The α5 subunit-containing gamma-amino butyric acid type A receptors(α5 GABAARs) are a distinct subpopulation that are specifically distributed in the mammalian hippocampus and also mediate tonic inhibitory currents ...The α5 subunit-containing gamma-amino butyric acid type A receptors(α5 GABAARs) are a distinct subpopulation that are specifically distributed in the mammalian hippocampus and also mediate tonic inhibitory currents in hippocampal neurons. These tonic currents can be enhanced by low-dose isoflurane, which is associated with learning and memory impairment. Inverse agonists of α5 GABAARs, such as L-655,708, are able to reverse the short-term memory deficit caused by low-dose isoflurane in young animals. However, whether these negative allosteric modulators have the same effects on aged rats remains unclear. In the present study, we mainly investigated the effects of L-655,708 on low-dose(1.3%) isoflurane-induced learning and memory impairment in elderly rats. Young(3-month-old) and aged(24-month-old) Wistar rats were randomly assigned to receive L-655,708 0.5 hour before or 23.5 hours after 1.3% isoflurane anesthesia.The Morris Water Maze tests demonstrated that L-655,708 injected before or after anesthesia could reverse the memory deficit in young rats. But in aged rats, application of L-655,708 only before anesthesia showed similar effects. Reverse transcription-polymerase chain reaction showed that low-dose isoflurane decreased the mRNA expression of α5 GABAARs in aging hippocampal neurons but increased that in young animals. These findings indicate that L-655,708 prevented but could not reverse 1.3% isoflurane-induced spatial learning and memory impairment in aged Wistar rats. All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Academy of Military Medical Science of China(approval No. NBCDSER-IACUC-2015128) in December 2015.展开更多
Neuropathic pain,often featuring allodynia,imposes significant physical and psychological burdens on patients,with limited treatments due to unclear central mechanisms.Addressing this challenge remains a crucial unsol...Neuropathic pain,often featuring allodynia,imposes significant physical and psychological burdens on patients,with limited treatments due to unclear central mechanisms.Addressing this challenge remains a crucial unsolved issue in pain medicine.Our previous study,using protein kinase C gamma(PKCγ)-tdTomato mice,highlights the spinal feedforward inhibitory circuit involving PKCγ neurons in gating neuropathic allodynia.However,the regulatory mechanisms governing this circuit necessitate further elucidation.We used diverse transgenic mice and advanced techniques to uncover the regulatory role of the descending serotonin(5-HT)facilitation system on spinal PKCγ neurons.Our findings revealed that 5-HT neurons from the rostral ventromedial medulla hyperpolarize spinal inhibitory interneurons via 5-HT_(2C) receptors,disinhibiting the feedforward inhibitory circuit involving PKCγ neurons and exacerbating allodynia.Inhibiting spinal 5-HT_(2C) receptors restored the feedforward inhibitory circuit,effectively preventing neuropathic allodynia.These insights offer promising therapeutic targets for neuropathic allodynia management,emphasizing the potential of spinal 5-HT_(2C) receptors as a novel avenue for intervention.展开更多
Expanding the specific surface area of substrates and carrying out precise surface engineering of imprinted nanocavities are crucial methods for enhancing the identification efficiency of molecularly imprinted polymer...Expanding the specific surface area of substrates and carrying out precise surface engineering of imprinted nanocavities are crucial methods for enhancing the identification efficiency of molecularly imprinted polymers(MIPs).To implement this synergistic strategy,bioinspired surface engineering was used to incorporate dual covalent receptors via precise post-imprinting modifications(PIMs)onto mesoporous silica nanosheets.The prepared sorbents(denoted as‘‘D-PMIPs”)were utilized to improve the specific identification of adenosine 5-monophosphate(AMP).Significantly,the mesoporous silica nanosheets possess a high surface area of approximately 498.73 m^(2)·g^(-1),which facilitates the formation of abundant specific recognition sites in the D-PMIPs.The dual covalent receptors are valuable for estab-lishing the spatial orientation and arrangement of AMP through multiple cooperative interactions.PIMs enable precise site-specific functionalization within the imprinted cavities,leading to the tailor-made formation of complementary binding sites.The maximum number of high-affinity binding sites(Nmax)of the D-PMIPs is 39.99 lmol·g^(-1),which is significantly higher than that of imprinted sorbents with a sin-gle receptor(i.e.,S-BMIPs or S-PMIPs).The kinetic data of the D-PMIPs can be effectively described by a pseudo-second-order model,indicating that the main binding mechanism involves synergistic chemisorption from boronate affinity and the pyrimidine base.This study suggests that using dual cova-lent receptors and PIMs is a reliable approach for creating imprinted sorbents with high selectivity,allow-ing for the controlled engineering of imprinted sites.展开更多
Objective To explore the possible differential trafficking properties of the dopamine D 1-like receptor subtypes, D 1 receptor and D5 receptor. Methods To visualize distributions of dopamine D 1-like receptor subtypes...Objective To explore the possible differential trafficking properties of the dopamine D 1-like receptor subtypes, D 1 receptor and D5 receptor. Methods To visualize distributions of dopamine D 1-like receptor subtypes at subcellular level, the yellow and cyan variants of green fluorescent protein （GFP） were used to tag D1 and D5 receptors. After transfection with the tagged dopamine receptors, the neuroblastoma cells NG108-15 were treated with D1 agonist SKF38393 or acetylcholine （ACh）. Then we observed the subcellular distributions of the tagged receptors under the confocal microscopy and tried to determine trafficking properties by comparing their distribution patterns before and after the drug treatment. Results In resting conditions, D 1 receptors located in the plasma membrane of NG108-15 cells, while D5 receptors located in both plasma membrane and cytosol. With the pre-treatment of SKF38393, the subcellular distribution of D1 receptors was changed. The yellow particle-like fluorescence of tagged D 1 receptors appeared in the cytosol, indicating that D 1 receptors were internalized into cytosol from the cell surface. Same situation also occurred in ACh pre-treatment. In contrast, the subcellular distribution of D5 receptors was not changed after SKF38393 or ACh treatment, indicating that D5R was not translocated to cell surface. Interestingly, when D1 and D5 receptors were co-expressed in the same cell, both kept their distinct subcellular distribution patterns and the trafficking properties. Conclusion Our present study reveals that in NG108-15 nerve cells, dopamine D1 and D5 receptors exhibit differential subcellular distribution patterns, and only D1 receptor has a marked trafficking response to the drug stimulation. We further discuss the potential role of the differential trafficking properties of D1-like receptors in complex modulation of DA signaling.展开更多
It has been reported that augmentative effect of tetrandrine on pentobarbital hypnosis in mice may be related to serotonergic system. The present study was undertaken to investigate the interaction of tetrandrine and ...It has been reported that augmentative effect of tetrandrine on pentobarbital hypnosis in mice may be related to serotonergic system. The present study was undertaken to investigate the interaction of tetrandrine and different 5-HT receptors on pentobarbital-induced sleep by using the loss-of-righting reflex method. The results showed that augmentative effect of tetrandrine on pentobarbital hypnosis in mice were potentiated by the p-MPPI （5-HT1A receptor antagonist） （1 mg/kg, i.p.） and ketanserin （5-HT2A/2C receptor antagonist） （1.5 mg/kg, i.p.）, respectively. Pretreatment with either 8-OH-DPAT （5-HT1A receptor agonist） （0.1 mg/kg, s.c.） or DOI （5-HT2A/2C receptor agonist） （0.2 mg/kg, i.p.） significantly decreased pentobarbital-induced sleep time, and tetrandrine （60 mg/kg, i.g.） significantly reversed this effect. These results suggest that both the 5-HTLA and 5-HT2A/2C subfamily may be involved in the potentiating mechanism of tetrandrine＇s effects on pantobarbital hypnosis.展开更多
Insomnia is a common sleep disorder without effective therapy and can affect a person's life.The mechanism of the disease is not completely understood.Hence,there is a need to understand the targets related to ins...Insomnia is a common sleep disorder without effective therapy and can affect a person's life.The mechanism of the disease is not completely understood.Hence,there is a need to understand the targets related to insomnia,in order to develop innovative therapies and new compounds.Recently,increasing interest has been focused on complementary and alternative medicines for treating or preventing insomnia.Research into their molecular components has revealed that their sedative and sleep-promoting properties rely on the interactions with various neurotransmitter systems in the brain.In this review,the role of 5-hydroxytryptamine(5-HT)in insomnia development is summarized,while a systematic analysis of studies is conducted to assess the mechanisms of herbal medicines on different 5-HT receptors subtypes,in order to provide reference for subsequent research.展开更多
Chronic loss of sleep damages health and disturbs the quality of life.Long-lasting sleep deprivation(SD)as well as sleep abnormalities are substantial risk factors for major depressive disorder,although the underlying...Chronic loss of sleep damages health and disturbs the quality of life.Long-lasting sleep deprivation(SD)as well as sleep abnormalities are substantial risk factors for major depressive disorder,although the underlying mechanisms are not clear.Here,we showed that chronic SD in mice promotes a gradual elevation of extracellular ATP,which activates astroglial P2X7 receptors(P2X7Rs).Activated P2X7Rs,in turn,selectively down-regulated the expression of 5-HT2B receptors(5-HT2BRs)in astrocytes.Stimulation of P2X7Rs induced by SD selectively suppressed the phosphorylation of AKT and FoxO3 a in astrocytes,but not in neurons.The overexpression of FoxO3a in astrocytes inhibited the expression of 5-HT2BRs.Down-regulation of 5-HT2BsRs instigated by SD suppressed the activation of STAT3 and relieved the inhibition of Ca2+-dependent phospholipase A2.This latter cascade promoted the release of arachidonic acid and prostaglandin E2.The depression-like behaviors induced by SD were alleviated in P2X7R-KO mice.Our study reveals the mechanism underlying chronic SD-induced depression-like behaviors and suggests 5-HT2BRs as a key target for exploring therapeutic strategies aimed at the depression evoked by sleep disorders.展开更多
Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was app...Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was applied in a rat model, adenosine 5-triphosphate disodium in the extracellular space was broken down into adenosine, which in turn inhibited pain transmission by means of an adenosine A1 receptor-dependent process. Direct injection of an adenosine A1 receptor agonist enhanced the analgesic effect of acupuncture. The analgesic effect of acupuncture appears to be mediated by activation of A1 receptors located on ascending nerves. In neuropathic pain, there is upregulation of P2X purinoceptor 3 （P2X3） receptor expression in dorsal root ganglion neurons. Conversely, the onset of mechanical hyperalgesia was diminished and established hyperalgesia was significantly reversed when P2X3 receptor expression was downregulated. The pathways upon which electroacupuncture appear to act are interwoven with pain pathways, and electroacupuncture stimuli converge with impulses originating from painful areas. Electroacupuncture may act via purinergic A1 and P2X3 receptors simultaneously to induce an analgesic effect on neuropathic pain.展开更多
BACKGROUND：Motoneurons from the Onuf’s nucleus of the spinal cord, which innervate the striated muscle of the pelvic floor, play an important role in erection, ejaculation, and urine control. Serotonin （5-hydroxytr...BACKGROUND：Motoneurons from the Onuf’s nucleus of the spinal cord, which innervate the striated muscle of the pelvic floor, play an important role in erection, ejaculation, and urine control. Serotonin （5-hydroxytryptamine, 5-HT） regulates motoneuron activity from the Onuf’s nucleus of the spinal cord. However, few studies exist that describe 5-HT receptor distribution in the Onuf’s nucleus. In addition, the nature of the effects of 5-HT receptor on the innervating striated muscle of the pelvic floor is controversial. OBJECTIVE： To investigate the distribution of serotonin 5-HT2A and 5-HT7 receptors in motoneurons of Onuf’s nucleus in the spinal cord of male rats, and to analyze the relationship of 5-HT2A and 5-HT7 receptor to central modulation of urogenital function. DESIGN, TIME AND SETTING： The neural morphology experiment was performed at the Ultramicro-structure Laboratory of Reproductive Medicine, Basic Medical College, Chongqing Medical University, China from April to December 2007. MATERIALS： Ten adult, Sprague Dawley rats （eight males and two females） were randomly divided into gender control group （n = 4, 50% male and 50% female） and a retrograde tracing group （n = 6, 100% male） Recombinant pseudorabies virus （PRV-152） was provided by Professor LW Enquist from Princeton University, USA. Rabbit anti-5-HT2A and 5-HT7 receptor antibodies were purchased from Diasorin, France. METHODS： In the gender control group, the spinal L5-6 segments were harvested, sliced, and then incubate antibodies specific against 5-HT2A or 5-HT7 receptors for immunohistochemical staining. In the retrograde tracing group, PRV-152 was separately injected into the right ischiocavernosus （ischiocavernosus subgroup, n = 3） and the right external urethral sphincter （external urethral sphincter subgroup, n = 3）. Four days after injection, L5-6 segments were harvested, sliced, and incubated with antibodies specific against 5-HT2A or 5-HT7 receptors for double-labeling immunofluorescence staining. MAIN OUTCOME MEASURES： Distribution analysis of 5-HT2A and 5-HT7 receptors in Onuf’s nucleus utilizing optical or laser confocal microscopy. RESULTS： 5-HT2A receptor immunoreactivity was revealed primarily in the medial region of the dorsolateral nucleus of Onuf’s nucleus. 5-HT7 receptor expression was observed in the lateral part of the dorso-lateral nucleus. 5-HT2A and 5-HT7 receptor expressions in the Onuf’s nucleus were significantly greater in male rats, compared to female rats. Double-labeling immunofluorescence demonstrated that 5-HT2A recepto were distributed primarily in the surrounding motoneurons innervating the ischiocavernosus, and 5-HT7 receptors were primarily expressed in motoneurons innervating the external urethral sphincter. CONCLUSION： Motoneurons innervating the ischiocavernosus and external urethral sphincter are located primarily in the medial and lateral region of the dorsolateral nucleus of L5-6 segments. The 5-HT2A receptor-innervating ischiocavernosus may be preferentially involved in the regulation of sexual reflex, and the 5-HT7 receptor-innervating external urethral sphincter may mainly join in regulating micturition reflex.展开更多
Metabotropic glutamate receptor subtype 5 (mGluR5) is a Group I mGlu subfamily of receptors coupled to the inositol trisphosphate/diacylglycerol pathway. Like other mGluR subtypes, mGluR5s contain a phylogenetically c...Metabotropic glutamate receptor subtype 5 (mGluR5) is a Group I mGlu subfamily of receptors coupled to the inositol trisphosphate/diacylglycerol pathway. Like other mGluR subtypes, mGluR5s contain a phylogenetically conserved, extracellular orthosteric binding site and a more variable allosteric binding site, located on the heptahelical transmembrane domain. The mGluR5 receptor has proved to be a key pharmacological target in conditions affecting the central nervous system (CNS) but its presence outside the CNS underscores its potential role in pathologies affecting peripheral organs such as the gastrointestinal (GI) tract and accessory digestive organs such as the tongue, liver and pancreas. Following identification of mGluR5s in the mouth, various studies have subsequently demonstrated its involvement in mechanical allodynia, inflammation, pain and oral cancer. mGluR5 expression has also been identified in gastroesophageal vagal pathways. Indeed, experimental and human studies have demonstrated that mGluR5 blockade reduces transient lower sphincter relaxation and reflux episodes. In the intestine, mGluR5s have been shown to be involved in the control of intestinal inflammation, visceral pain and the epithelial barrier function. In the liver, mGluR5s have a permissive role in the onset of ischemic injury in rat and mice hepatocytes. Conversely, livers from mice treated with selective negative allosteric modulators and mGluR5 knockout mice are protected against ischemic injury. Similar results have been observed in experimental models of free-radical injury and in vivo mouse models of acetaminophen intoxication. Finally, mGluR5s in the pancreas are associated with insulin secretion control. The picture is, however, far from complete as the review attempts to establish in particular as regards identifying specific targets and innovative therapeutic approaches for the treatment of GI disorders.展开更多
BACKGROUND Melanocortin 3 and 5 receptors(i.e.,MC3R and MC5R)belong to the melanocortin family.However,data regarding their role in inflammatory bowel diseases(IBD)are currently unavailable.AIM This study aims to asce...BACKGROUND Melanocortin 3 and 5 receptors(i.e.,MC3R and MC5R)belong to the melanocortin family.However,data regarding their role in inflammatory bowel diseases(IBD)are currently unavailable.AIM This study aims to ascertain their expression profiles in the colonic mucosa of Crohn’s disease(CD)and ulcerative colitis(UC),aligning them with IBD disease endoscopic and histologic activity.METHODS Colonic mucosal biopsies from CD/UC patients were sampled,and immunohisto-chemical analyses were conducted to evaluate the expression of MC3R and MC5R.Colonic sampling was performed on both traits with endoscopic scores(Mayo endoscopic score and CD endoscopic index of severity)consistent with inflamed mucosa and not consistent with disease activity(i.e.,normal appearing mucosa).RESULTS In both CD and UC inflamed mucosa,MC3R(CD:+7.7 fold vs normal mucosa,P<0.01;UC:+12 fold vs normal mucosa,P<0.01)and MC5R(CD:+5.5 fold vs normal mucosa,P<0.01;UC:+8.1 fold vs normal mucosa,P<0.01)were significantly more expressed compared to normal mucosa.CONCLUSION MC3R and MC5R are expressed in the colon of IBD patients.Furthermore,expression may differ according to disease endoscopic activity,with a higher degree of expression in the traits affected by disease activity in both CD and UC,suggesting a potential use of these receptors in IBD pharmacology.展开更多
5-Hydroxytryptamine(5-HT)type 3 receptor(5-HT_(3)R)is the only type of ligand-gated ion channel in the 5-HT receptor family.Through the high permeability of Na+,K+,and Ca2+and activation of subsequent voltage-gated ca...5-Hydroxytryptamine(5-HT)type 3 receptor(5-HT_(3)R)is the only type of ligand-gated ion channel in the 5-HT receptor family.Through the high permeability of Na+,K+,and Ca2+and activation of subsequent voltage-gated calcium channels(VGCCs),5-HT_(3)R induces a rapid increase of neuronal excitability or the release of neurotransmitters from axon terminals in the central nervous system(CNS).5-HT_(3)Rs are widely expressed in the medial prefrontal cortex(mPFC),amygdala(AMYG),hippocampus(HIP),periaqueductal gray(PAG),and other brain regions closely associated with anxiety reactions.They have a bidirectional regulatory effect on anxiety reactions by acting on different types of cells in different brain regions.5-HT_(3)Rs mediate the activation of the cholecystokinin(CCK)system in the AMYG,and theγ-aminobutyric acid(GABA)“disinhibition”mechanism in the prelimbic area of the mPFC promotes anxiety by the activation of GABAergic intermediate inhibitory neurons(IINs).In contrast,a 5-HT_(3)R-induced GABA“disinhibition”mechanism in the infralimbic area of the mPFC and the ventral HIP produces anxiolytic effects.5-HT_(2)R-mediated regulation of anxiety reactions are also activated by 5-HT_(3)R-activated 5-HT release in the HIP and PAG.This provides a theoretical basis for the treatment of anxiety disorders or the production of anxiolytic drugs by targeting 5-HT_(3)Rs.However,given the circuit specific modulation of 5-HT_(3)Rs on emotion,systemic use of 5-HT_(3)R agonism or antagonism alone seems unlikely to remedy anxiety,which deeply hinders the current clinical application of 5-HT_(3)R drugs.Therefore,the exploitation of circuit targeting methods or a combined drug strategy might be a useful developmental approach in the future.展开更多
AIM： To delineate the mechanisms of renal vasoconstriction in hepatorenal syndrome （HRS）, we investigated the expression of type I inositol 1, 4, 5-triphosphate receptors （IP3R I） of kidney in mice with fulminant...AIM： To delineate the mechanisms of renal vasoconstriction in hepatorenal syndrome （HRS）, we investigated the expression of type I inositol 1, 4, 5-triphosphate receptors （IP3R I） of kidney in mice with fulminant hepatic failure （FHF）. METHODS： FHF was induced by lipopolysaccharide （LPS） in D-galactosamine （GAIN） sensitized BALB/c mice. There were 20 mice in normal saline （NS）-treated group, 20 mice in LPS-treated group, 20 mice in GaIN- treated group, and 60 mice in GalN/LPS-treated group （FHF group）. Liver and kidney tissues were obtained at 2, 6, and 9 h after administration. The liver and kidney specimens were stained with hematoxylin-eosin for studying morphological changes under light microscope. The expression of IP3R I in kidney tissue was tested by immunohistochemistry, Western blot and reverse transcription （RT）-PCR. RESULTS： Kidney tissues were morphologically normal at all time points in all groups. IP3R I proteins were found localized in the plasma region of glomerular mesangial cells （GMC） and vascular smooth muscle cells （VSMC） in kidney by immunohistochemical staining. In kidney of mice with FHF at 6 h and 9 h IP3R I staining was upregulated. Results from Western blot demonstrated consistent and significant increment of IP3R I expression in mice with FHF at 6 h and 9 h （t = 3.16, P 〈 0.05; t = 5.43, P 〈 0.01）. Furthermore, we evaluated IP3R I mRNA expression by RT-PCR and observed marked upregulation of IP3R I mRNA in FHF samples at 2 h, 6 h and 9 h compared to controls （t = 2.97, P 〈 0.05; t = 4.42, P 〈 0.01; t = 3.81, P 〈 0.01）. CONCLUSION： The expression of IP3R I protein increased in GMC and renal VSMC of mice with FHF, possibly caused by up-regulation of IP3R I mRNA.展开更多
BACKGROUND C-X-C chemokine receptor type 5(CXCR5)^(+)CD8^(+)T cells represent a unique immune subset with dual roles,functioning as cytotoxic cells in persistent viral infections while promoting B cell responses.Despi...BACKGROUND C-X-C chemokine receptor type 5(CXCR5)^(+)CD8^(+)T cells represent a unique immune subset with dual roles,functioning as cytotoxic cells in persistent viral infections while promoting B cell responses.Despite their importance,the specific role of CXCR5^(+)CD8^(+)T cells in chronic hepatitis B(CHB),particularly during interferon-alpha(IFN-α)treatment,is not fully understood.This study aims to elucidate the relationship between CXCR5^(+)CD8^(+)T cells and sustained serologic response(SR)in patients undergoing 48 weeks of pegylated IFN-α(peg-IFN-α)treatment for CHB.AIM To elucidate the relationship between CXCR5^(+)CD8^(+)T cells and sustained SR in patients undergoing 48 weeks of peg-IFN-αtreatment for CHB.METHODS This study enrolled 60 patients with hepatitis Be antigen(HBeAg)-positive CHB undergoing 48 weeks of peg-IFN-αtreatment.Participants were assessed for eligibility based on criteria such as persistent HBsAg-positive status for at least six months,HBeAb-negative,hepatitis B virus DNA levels exceeding 2×10^(4) copies/mL,and alanine aminotransferase(ALT)levels between 2 and 10 times the upper limit of normal.Blood samples were collected at baseline and at weeks 12,24,48,and a 24-week treatment-free follow-up(week 72)to measure serum interleukin(IL)-21 concentration via ELISA and to analyze CXCR5 and programmed death-ligand 1(PD-L1)expression on CD8^(+)T cells by flow cytometry,CXCR5 is a chemokine receptor that directs immune cells to specific tissues,while PD-L1 is a protein that regulates immune responses by inhibiting T cell activity.RESULTS Patients with CHB exhibited significantly lower levels of circulating CXCR5^(+)CD8^(+)T cells compared to healthy controls(P<0.01).Notably,CXCR5^(+)CD8^(+)T cells were prominently expressed in patients who achieved sustained SR compared to non-SR(NSR).A significant correlation was observed between CXCR5 and PD-L1 expression(r=-0.189,P=0.002).However,there was no significant correlation between serum IL-21 levels and CXCR5+CD8+lymphocytes(r=-0.03,P=0.625)or serum ALT levels(r=0.026,P=0.678).CONCLUSION The enhanced expression of CXCR5^(+)CD8^(+)T cells in patients achieving HBeAg seroconversion during IFN-αtreatment suggests that these cells play a crucial role in antiviral immune responses against hepatitis B.This study highlights the potential of CXCR5^(+)CD8^(+)T cells as immune regulators in CHB,which may inform future therapeutic strategies to optimize antiviral treatments.展开更多
Irritable bowel syndrome(IBS)is a common functional bowel disorder characterized by abdominal pain and visceral hypersensitivity.Reducing visceral hypersensitivity is the key to effectively relieving abdominal pain in...Irritable bowel syndrome(IBS)is a common functional bowel disorder characterized by abdominal pain and visceral hypersensitivity.Reducing visceral hypersensitivity is the key to effectively relieving abdominal pain in IBS.Increasing evidence has confirmed that the thalamic nucleus reuniens(Re)and 5-hydroxytryptamine(5-HT)neurotransmitter system play an important role in the development of colorectal visceral pain,whereas the exact mechanisms remain largely unclear.In this study,we found that high expression of the 5-HT2B receptors in the Re glutamatergic neurons promoted colorectal visceral pain.Specifically,we found that neonatal maternal deprivation(NMD)mice exhibited visceral hyperalgesia and enhanced spontaneous synaptic transmission in the Re brain region.Colorectal distension(CRD)stimulation induced a large amount of c-Fos expression in the Re brain region of NMD mice,predominantly in glutamatergic neurons.Furthermore,optogenetic manipulation of glutamatergic neuronal activity in the Re altered colorectal visceral pain responses in CON and NMD mice.In addition,we demonstrated that 5-HT2B receptor expression on the Re glutamatergic neurons was upregulated and ultimately promoted colorectal visceral pain in NMD mice.These findings suggest a critical role of the 5HT2B receptors on the Re glutamatergic neurons in the regulation of colorectal visceral pain.展开更多
The present study aimed at evaluation of prophylactic efficacy and possible mechanisms of asiaticoside （AS） based standardized extract of Centella asiatica （L.） Urban leaves （INDCA） in animal models of migraine....The present study aimed at evaluation of prophylactic efficacy and possible mechanisms of asiaticoside （AS） based standardized extract of Centella asiatica （L.） Urban leaves （INDCA） in animal models of migraine. The effects of oral and intranasal （i.n.） pretreatment of INDCA （acute and 7-days subacute） were evaluated against nitroglycerine （NTG, 10 mg·kg^-1, i.p.） and bradykinin （BK, 10 μg, intra-arterial） induced hyperalgesia in rats. Tail flick latencies （from 0 to 240 rain） post-NTG treatment and the number of vocalizations post-BK treatment were recorded as a measure of hyperalgesia. Separate groups of rats for negative （Normal） and positive （sumatriptan, 42 mg.kg ^-1, s.c.） controls were included. The interaction of 1NDCA with selective 5-HT1A, 5-HT1B, and 5-HTI D receptor antagonists （NAN-190, Isamoltane hemifumarate, and BRL-15572 respectively） against NTG-induced hyperalgesia was also evaluated. Acute and sub-acute pre-treatment of INDCA [10 and 30 mg.kg^-1 （oral） and 100 μg/rat （i.n.） showed significant anti-nociception activity, and reversal of the NTG-induced hypera｜gesia and brain 5-HT concentration decline. Oral pre-treatment with INDCA （30 mg·kg ^-1, 7 d） showed significant reduction in the number of vocalization. The anti-nociceptive effects of INDCA were blocked by 5-HTIA and 5-HT1B but not 5-HT1D receptor antagonists. In conclusion, 1NDCA demonstrated promising anti-nociceptive effects in animal models of migraine, probably through 5-HT1A/1B medicated action.展开更多
Uncariae Ramulus Cum Uncis(Gou-Teng),the dried hook-bearing stems of several Uncaria plants(Rubiaceae),is a wellknown herbal medicine in China.The clinical application of Gou-Teng is bewildered for the morphological a...Uncariae Ramulus Cum Uncis(Gou-Teng),the dried hook-bearing stems of several Uncaria plants(Rubiaceae),is a wellknown herbal medicine in China.The clinical application of Gou-Teng is bewildered for the morphological and chemical similarity between diferent species.In order to discern their chemical and biological diference,an ultra-fast liquid chromatography equipped with ion trap time-of-fight mass spectrometry(UFLC-IT/TOF-MS)combining with melatonin(MT1 and MT2)and 5-hydroxytryptamine(5-HT1A and 5-HT2C)receptors agonistic assay in vitro was conducted on seven Uncaria species.As a result,57 compounds including 35 indole alkaloids,ten favonoids,fve triterpenoids,fve chlorogenic analogues,and two other compounds were characterized based on their MS/MS patterns and UV absorptions.Specifcally,cadambine-type and corynanthein-type alkaloids were exclusively present in U.rhynchophylla and U.scandens,whereas corynoxine-type alkaloids were commonly detected in all the seven Uncaria plants.Three Uncaria species,U.rhynchophylla,U.macrophylla,and U.yunnanensis showed obviously agnostic activity on four neurotransmitter receptors(MT1,MT2,5-HT1A,and 5-HT_(2C)).This frst-time UFLCMS-IT-TOF analyses integrated with biological assay on seven Uncaria plants will provide scientifc viewpoints for the clinical application of Gou-Teng.展开更多
This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique...This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique. The results showed that: (1) The majority of examined neurons (78.70%) were sensitive to 5-HT (3–300 μmol/L). 5-HT induced inward currents in a concentration-dependent manner and the currents were blocked by ICS 205-930 (1 μmol/L), a selective antagonist of the 5-HT3 receptor; (2) Pre-application of WIN55,212-2 (0.01–1 μmol/L) significantly inhibited I5-HT3 reversibly in concentration-dependent and voltage-independent manners. The concentra-tion-response curve of 5-HT3 receptor was shifted downward by WIN55,212-2 without any change of the threshold value. The EC50 values of two curves were very close (17.5±4.5) mmol/L vs. (15.2±4.5) mmol/L and WIN55,212-2 decreased the maximal amplitude of I5-HT3 by (48.65±4.15)%; (3) Neither AM281, a selective CB1 receptor antagonist, nor AM630, a selective CB2 receptor antagonist reversed the inhibition of I5-HT3 by WIN55,212-2; (4) When WIN55,212-2 was given from 15 to 120 s before 5-HT application, inhibitory effect was gradually increased and the maximal inhibition took place at 90 s, and the inhibition remained at the same level after 90 s. We are led to concluded that-WIN55,212-2 inhibited I5-HT3 significantly and neither CB1 receptor antagonist nor CB2 receptor antagonist could reverse the inhibition of I5-HT3 by WIN55,212-2. Moreover, WIN55,212-2 is not an open channel blocker (OCB) of 5-HT3 receptor. WIN55,212-2 significantly inhibited 5-HT-activated currents in a non-competitive manner. The inhibition of I5-HT3 by WIN55,212-2 is probably new one of peripheral analgesic mechanisms of WIN55,212-2, but the mechanism by which WIN55,212-2 inhibits I5-HT3 warrants further investigation.展开更多
BACKGROUND The global prevalence of metabolic dysfunction-associated steatotic liver disease(MASLD)has continued to increase annually.Recent studies have indicated that inhibition of metabotropic glutamate receptor 5(...BACKGROUND The global prevalence of metabolic dysfunction-associated steatotic liver disease(MASLD)has continued to increase annually.Recent studies have indicated that inhibition of metabotropic glutamate receptor 5(mGluR5)may alleviate hepatic steatosis.However,the precise mechanism warrants further exploration.AIM To investigate the potential mechanism by which mGluR5 attenuates hepatocyte steatosis in vitro and in vivo.METHODS Free fatty acids(FFAs)-stimulated HepG2 cells were treated with the mGluR5 antagonist MPEP and the mGluR5 agonist CHPG.Oil Red O staining and a triglyceride assay kit were used to evaluate lipid content.Western blot analysis was conducted to detect the expression of the autophagy-associated proteins p62 and LC3-II,as well as the expression of the key signaling molecules AMPK and ULK1,in the treated cells.To further elucidate the contributions of autophagy and AMPK,we used chloroquine(CQ)to inhibit autophagy and compound C(CC)to inhibit AMPK activity.In parallel,wild-type mice and mGluR5 knockout(KO)mice fed a normal chow diet or a high-fat diet(HFD)were used to evaluate the effect of mGluR5 inhibition in vivo.RESULTS mGluR5 inhibition by MPEP attenuated hepatocellular steatosis and increased LC3-II and p62 protein expression.The autophagy inhibitor CQ reversed the effects of MPEP.In addition,MPEP promoted AMPK and ULK1 expression in HepG2 cells exposed to FFAs.MPEP treatment led to the nuclear translocation of transcription factor EB,which is known to promote p62 expression.This effect was negated by the AMPK inhibitor CC.mGluR5 KO mice presented reduced body weight,improved glucose tolerance and reduced hyperlipidemia when fed a HFD.Additionally,the livers of HFD-fed mGluR5 KO mice presented increases in LC3-II and p62.CONCLUSION Our results suggest that mGluR5 inhibition promoted autophagy and reduced hepatocyte steatosis through activation of the AMPK signaling pathway.These findings reveal a new functional mechanism of mGluR5 as a target in the treatment of MASLD.展开更多
文摘The α5 subunit-containing gamma-amino butyric acid type A receptors(α5 GABAARs) are a distinct subpopulation that are specifically distributed in the mammalian hippocampus and also mediate tonic inhibitory currents in hippocampal neurons. These tonic currents can be enhanced by low-dose isoflurane, which is associated with learning and memory impairment. Inverse agonists of α5 GABAARs, such as L-655,708, are able to reverse the short-term memory deficit caused by low-dose isoflurane in young animals. However, whether these negative allosteric modulators have the same effects on aged rats remains unclear. In the present study, we mainly investigated the effects of L-655,708 on low-dose(1.3%) isoflurane-induced learning and memory impairment in elderly rats. Young(3-month-old) and aged(24-month-old) Wistar rats were randomly assigned to receive L-655,708 0.5 hour before or 23.5 hours after 1.3% isoflurane anesthesia.The Morris Water Maze tests demonstrated that L-655,708 injected before or after anesthesia could reverse the memory deficit in young rats. But in aged rats, application of L-655,708 only before anesthesia showed similar effects. Reverse transcription-polymerase chain reaction showed that low-dose isoflurane decreased the mRNA expression of α5 GABAARs in aging hippocampal neurons but increased that in young animals. These findings indicate that L-655,708 prevented but could not reverse 1.3% isoflurane-induced spatial learning and memory impairment in aged Wistar rats. All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Academy of Military Medical Science of China(approval No. NBCDSER-IACUC-2015128) in December 2015.
基金supported by the National Natural Science Foundation of China(81971058,82371226,82101295,82301398)the National Funded Postdoctoral Researcher Program(GZC20233585)The Boost Plan of Xijing Hospital(XJZT24QN25,XJZT25CX22).
文摘Neuropathic pain,often featuring allodynia,imposes significant physical and psychological burdens on patients,with limited treatments due to unclear central mechanisms.Addressing this challenge remains a crucial unsolved issue in pain medicine.Our previous study,using protein kinase C gamma(PKCγ)-tdTomato mice,highlights the spinal feedforward inhibitory circuit involving PKCγ neurons in gating neuropathic allodynia.However,the regulatory mechanisms governing this circuit necessitate further elucidation.We used diverse transgenic mice and advanced techniques to uncover the regulatory role of the descending serotonin(5-HT)facilitation system on spinal PKCγ neurons.Our findings revealed that 5-HT neurons from the rostral ventromedial medulla hyperpolarize spinal inhibitory interneurons via 5-HT_(2C) receptors,disinhibiting the feedforward inhibitory circuit involving PKCγ neurons and exacerbating allodynia.Inhibiting spinal 5-HT_(2C) receptors restored the feedforward inhibitory circuit,effectively preventing neuropathic allodynia.These insights offer promising therapeutic targets for neuropathic allodynia management,emphasizing the potential of spinal 5-HT_(2C) receptors as a novel avenue for intervention.
基金supported by the National Natural Science Foundation of China(22078132,22108103,and U22A20413)the Open Funding Project of the National Key Labora-tory of Biochemical Engineering(2021KF-02)+3 种基金China Postdoctoral Science Foundation(2021M691301)Jiangsu Key Research and Development Program(BE2022356)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(CPSF)(GZ20230989)Jiangsu Agricultural Independent Innovation Fund Project(CX(21)3079).
文摘Expanding the specific surface area of substrates and carrying out precise surface engineering of imprinted nanocavities are crucial methods for enhancing the identification efficiency of molecularly imprinted polymers(MIPs).To implement this synergistic strategy,bioinspired surface engineering was used to incorporate dual covalent receptors via precise post-imprinting modifications(PIMs)onto mesoporous silica nanosheets.The prepared sorbents(denoted as‘‘D-PMIPs”)were utilized to improve the specific identification of adenosine 5-monophosphate(AMP).Significantly,the mesoporous silica nanosheets possess a high surface area of approximately 498.73 m^(2)·g^(-1),which facilitates the formation of abundant specific recognition sites in the D-PMIPs.The dual covalent receptors are valuable for estab-lishing the spatial orientation and arrangement of AMP through multiple cooperative interactions.PIMs enable precise site-specific functionalization within the imprinted cavities,leading to the tailor-made formation of complementary binding sites.The maximum number of high-affinity binding sites(Nmax)of the D-PMIPs is 39.99 lmol·g^(-1),which is significantly higher than that of imprinted sorbents with a sin-gle receptor(i.e.,S-BMIPs or S-PMIPs).The kinetic data of the D-PMIPs can be effectively described by a pseudo-second-order model,indicating that the main binding mechanism involves synergistic chemisorption from boronate affinity and the pyrimidine base.This study suggests that using dual cova-lent receptors and PIMs is a reliable approach for creating imprinted sorbents with high selectivity,allow-ing for the controlled engineering of imprinted sites.
文摘Objective To explore the possible differential trafficking properties of the dopamine D 1-like receptor subtypes, D 1 receptor and D5 receptor. Methods To visualize distributions of dopamine D 1-like receptor subtypes at subcellular level, the yellow and cyan variants of green fluorescent protein （GFP） were used to tag D1 and D5 receptors. After transfection with the tagged dopamine receptors, the neuroblastoma cells NG108-15 were treated with D1 agonist SKF38393 or acetylcholine （ACh）. Then we observed the subcellular distributions of the tagged receptors under the confocal microscopy and tried to determine trafficking properties by comparing their distribution patterns before and after the drug treatment. Results In resting conditions, D 1 receptors located in the plasma membrane of NG108-15 cells, while D5 receptors located in both plasma membrane and cytosol. With the pre-treatment of SKF38393, the subcellular distribution of D1 receptors was changed. The yellow particle-like fluorescence of tagged D 1 receptors appeared in the cytosol, indicating that D 1 receptors were internalized into cytosol from the cell surface. Same situation also occurred in ACh pre-treatment. In contrast, the subcellular distribution of D5 receptors was not changed after SKF38393 or ACh treatment, indicating that D5R was not translocated to cell surface. Interestingly, when D1 and D5 receptors were co-expressed in the same cell, both kept their distinct subcellular distribution patterns and the trafficking properties. Conclusion Our present study reveals that in NG108-15 nerve cells, dopamine D1 and D5 receptors exhibit differential subcellular distribution patterns, and only D1 receptor has a marked trafficking response to the drug stimulation. We further discuss the potential role of the differential trafficking properties of D1-like receptors in complex modulation of DA signaling.
基金National Natural Science Foundation of China(Grant No.30772556 and 30640070)Research Fund of Janssen Research Council and the‘985'Project in Peking University.
文摘It has been reported that augmentative effect of tetrandrine on pentobarbital hypnosis in mice may be related to serotonergic system. The present study was undertaken to investigate the interaction of tetrandrine and different 5-HT receptors on pentobarbital-induced sleep by using the loss-of-righting reflex method. The results showed that augmentative effect of tetrandrine on pentobarbital hypnosis in mice were potentiated by the p-MPPI （5-HT1A receptor antagonist） （1 mg/kg, i.p.） and ketanserin （5-HT2A/2C receptor antagonist） （1.5 mg/kg, i.p.）, respectively. Pretreatment with either 8-OH-DPAT （5-HT1A receptor agonist） （0.1 mg/kg, s.c.） or DOI （5-HT2A/2C receptor agonist） （0.2 mg/kg, i.p.） significantly decreased pentobarbital-induced sleep time, and tetrandrine （60 mg/kg, i.g.） significantly reversed this effect. These results suggest that both the 5-HTLA and 5-HT2A/2C subfamily may be involved in the potentiating mechanism of tetrandrine＇s effects on pantobarbital hypnosis.
基金supported by the National Natural Science Foundation of China(Nos.82174091,82122066,81973291,and 82003909)the National Key R&D Program of China(No.2022YFC2704603).
文摘Insomnia is a common sleep disorder without effective therapy and can affect a person's life.The mechanism of the disease is not completely understood.Hence,there is a need to understand the targets related to insomnia,in order to develop innovative therapies and new compounds.Recently,increasing interest has been focused on complementary and alternative medicines for treating or preventing insomnia.Research into their molecular components has revealed that their sedative and sleep-promoting properties rely on the interactions with various neurotransmitter systems in the brain.In this review,the role of 5-hydroxytryptamine(5-HT)in insomnia development is summarized,while a systematic analysis of studies is conducted to assess the mechanisms of herbal medicines on different 5-HT receptors subtypes,in order to provide reference for subsequent research.
基金the National Natural Science Foundation of China(81871852,81200935,81671862,and 81871529)Liaoning Revitalization Talents Program(XLYC1807137)+1 种基金the Scientific Research Foundation for Overseas Scholars of the Education Ministry of China(20151098)the Natural Science Foundation of Liaoning Province,China(20170541030)。
文摘Chronic loss of sleep damages health and disturbs the quality of life.Long-lasting sleep deprivation(SD)as well as sleep abnormalities are substantial risk factors for major depressive disorder,although the underlying mechanisms are not clear.Here,we showed that chronic SD in mice promotes a gradual elevation of extracellular ATP,which activates astroglial P2X7 receptors(P2X7Rs).Activated P2X7Rs,in turn,selectively down-regulated the expression of 5-HT2B receptors(5-HT2BRs)in astrocytes.Stimulation of P2X7Rs induced by SD selectively suppressed the phosphorylation of AKT and FoxO3 a in astrocytes,but not in neurons.The overexpression of FoxO3a in astrocytes inhibited the expression of 5-HT2BRs.Down-regulation of 5-HT2BsRs instigated by SD suppressed the activation of STAT3 and relieved the inhibition of Ca2+-dependent phospholipase A2.This latter cascade promoted the release of arachidonic acid and prostaglandin E2.The depression-like behaviors induced by SD were alleviated in P2X7R-KO mice.Our study reveals the mechanism underlying chronic SD-induced depression-like behaviors and suggests 5-HT2BRs as a key target for exploring therapeutic strategies aimed at the depression evoked by sleep disorders.
文摘Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was applied in a rat model, adenosine 5-triphosphate disodium in the extracellular space was broken down into adenosine, which in turn inhibited pain transmission by means of an adenosine A1 receptor-dependent process. Direct injection of an adenosine A1 receptor agonist enhanced the analgesic effect of acupuncture. The analgesic effect of acupuncture appears to be mediated by activation of A1 receptors located on ascending nerves. In neuropathic pain, there is upregulation of P2X purinoceptor 3 （P2X3） receptor expression in dorsal root ganglion neurons. Conversely, the onset of mechanical hyperalgesia was diminished and established hyperalgesia was significantly reversed when P2X3 receptor expression was downregulated. The pathways upon which electroacupuncture appear to act are interwoven with pain pathways, and electroacupuncture stimuli converge with impulses originating from painful areas. Electroacupuncture may act via purinergic A1 and P2X3 receptors simultaneously to induce an analgesic effect on neuropathic pain.
基金the Natural Science Foundation of Chongqing City, No. CSTC2006BB5037
文摘BACKGROUND：Motoneurons from the Onuf’s nucleus of the spinal cord, which innervate the striated muscle of the pelvic floor, play an important role in erection, ejaculation, and urine control. Serotonin （5-hydroxytryptamine, 5-HT） regulates motoneuron activity from the Onuf’s nucleus of the spinal cord. However, few studies exist that describe 5-HT receptor distribution in the Onuf’s nucleus. In addition, the nature of the effects of 5-HT receptor on the innervating striated muscle of the pelvic floor is controversial. OBJECTIVE： To investigate the distribution of serotonin 5-HT2A and 5-HT7 receptors in motoneurons of Onuf’s nucleus in the spinal cord of male rats, and to analyze the relationship of 5-HT2A and 5-HT7 receptor to central modulation of urogenital function. DESIGN, TIME AND SETTING： The neural morphology experiment was performed at the Ultramicro-structure Laboratory of Reproductive Medicine, Basic Medical College, Chongqing Medical University, China from April to December 2007. MATERIALS： Ten adult, Sprague Dawley rats （eight males and two females） were randomly divided into gender control group （n = 4, 50% male and 50% female） and a retrograde tracing group （n = 6, 100% male） Recombinant pseudorabies virus （PRV-152） was provided by Professor LW Enquist from Princeton University, USA. Rabbit anti-5-HT2A and 5-HT7 receptor antibodies were purchased from Diasorin, France. METHODS： In the gender control group, the spinal L5-6 segments were harvested, sliced, and then incubate antibodies specific against 5-HT2A or 5-HT7 receptors for immunohistochemical staining. In the retrograde tracing group, PRV-152 was separately injected into the right ischiocavernosus （ischiocavernosus subgroup, n = 3） and the right external urethral sphincter （external urethral sphincter subgroup, n = 3）. Four days after injection, L5-6 segments were harvested, sliced, and incubated with antibodies specific against 5-HT2A or 5-HT7 receptors for double-labeling immunofluorescence staining. MAIN OUTCOME MEASURES： Distribution analysis of 5-HT2A and 5-HT7 receptors in Onuf’s nucleus utilizing optical or laser confocal microscopy. RESULTS： 5-HT2A receptor immunoreactivity was revealed primarily in the medial region of the dorsolateral nucleus of Onuf’s nucleus. 5-HT7 receptor expression was observed in the lateral part of the dorso-lateral nucleus. 5-HT2A and 5-HT7 receptor expressions in the Onuf’s nucleus were significantly greater in male rats, compared to female rats. Double-labeling immunofluorescence demonstrated that 5-HT2A recepto were distributed primarily in the surrounding motoneurons innervating the ischiocavernosus, and 5-HT7 receptors were primarily expressed in motoneurons innervating the external urethral sphincter. CONCLUSION： Motoneurons innervating the ischiocavernosus and external urethral sphincter are located primarily in the medial and lateral region of the dorsolateral nucleus of L5-6 segments. The 5-HT2A receptor-innervating ischiocavernosus may be preferentially involved in the regulation of sexual reflex, and the 5-HT7 receptor-innervating external urethral sphincter may mainly join in regulating micturition reflex.
基金Supported by Italian ministry of University,Research and Instruction
文摘Metabotropic glutamate receptor subtype 5 (mGluR5) is a Group I mGlu subfamily of receptors coupled to the inositol trisphosphate/diacylglycerol pathway. Like other mGluR subtypes, mGluR5s contain a phylogenetically conserved, extracellular orthosteric binding site and a more variable allosteric binding site, located on the heptahelical transmembrane domain. The mGluR5 receptor has proved to be a key pharmacological target in conditions affecting the central nervous system (CNS) but its presence outside the CNS underscores its potential role in pathologies affecting peripheral organs such as the gastrointestinal (GI) tract and accessory digestive organs such as the tongue, liver and pancreas. Following identification of mGluR5s in the mouth, various studies have subsequently demonstrated its involvement in mechanical allodynia, inflammation, pain and oral cancer. mGluR5 expression has also been identified in gastroesophageal vagal pathways. Indeed, experimental and human studies have demonstrated that mGluR5 blockade reduces transient lower sphincter relaxation and reflux episodes. In the intestine, mGluR5s have been shown to be involved in the control of intestinal inflammation, visceral pain and the epithelial barrier function. In the liver, mGluR5s have a permissive role in the onset of ischemic injury in rat and mice hepatocytes. Conversely, livers from mice treated with selective negative allosteric modulators and mGluR5 knockout mice are protected against ischemic injury. Similar results have been observed in experimental models of free-radical injury and in vivo mouse models of acetaminophen intoxication. Finally, mGluR5s in the pancreas are associated with insulin secretion control. The picture is, however, far from complete as the review attempts to establish in particular as regards identifying specific targets and innovative therapeutic approaches for the treatment of GI disorders.
基金The study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of University of Campania Luigi Vanvitelli(Protocol code 795 on December 23,2019).
文摘BACKGROUND Melanocortin 3 and 5 receptors(i.e.,MC3R and MC5R)belong to the melanocortin family.However,data regarding their role in inflammatory bowel diseases(IBD)are currently unavailable.AIM This study aims to ascertain their expression profiles in the colonic mucosa of Crohn’s disease(CD)and ulcerative colitis(UC),aligning them with IBD disease endoscopic and histologic activity.METHODS Colonic mucosal biopsies from CD/UC patients were sampled,and immunohisto-chemical analyses were conducted to evaluate the expression of MC3R and MC5R.Colonic sampling was performed on both traits with endoscopic scores(Mayo endoscopic score and CD endoscopic index of severity)consistent with inflamed mucosa and not consistent with disease activity(i.e.,normal appearing mucosa).RESULTS In both CD and UC inflamed mucosa,MC3R(CD:+7.7 fold vs normal mucosa,P<0.01;UC:+12 fold vs normal mucosa,P<0.01)and MC5R(CD:+5.5 fold vs normal mucosa,P<0.01;UC:+8.1 fold vs normal mucosa,P<0.01)were significantly more expressed compared to normal mucosa.CONCLUSION MC3R and MC5R are expressed in the colon of IBD patients.Furthermore,expression may differ according to disease endoscopic activity,with a higher degree of expression in the traits affected by disease activity in both CD and UC,suggesting a potential use of these receptors in IBD pharmacology.
基金supported by the National Natural Science Foundation of China(Nos.82071516,32171065,91949105,and 81771227)the Innovation Capability Support Program of Shannxi Province in China(No.2020TD-037)the Fundamental Research Funds for the Central Universities(Nos.GK202105001,GK202205019,and CK202205022),China.
文摘5-Hydroxytryptamine(5-HT)type 3 receptor(5-HT_(3)R)is the only type of ligand-gated ion channel in the 5-HT receptor family.Through the high permeability of Na+,K+,and Ca2+and activation of subsequent voltage-gated calcium channels(VGCCs),5-HT_(3)R induces a rapid increase of neuronal excitability or the release of neurotransmitters from axon terminals in the central nervous system(CNS).5-HT_(3)Rs are widely expressed in the medial prefrontal cortex(mPFC),amygdala(AMYG),hippocampus(HIP),periaqueductal gray(PAG),and other brain regions closely associated with anxiety reactions.They have a bidirectional regulatory effect on anxiety reactions by acting on different types of cells in different brain regions.5-HT_(3)Rs mediate the activation of the cholecystokinin(CCK)system in the AMYG,and theγ-aminobutyric acid(GABA)“disinhibition”mechanism in the prelimbic area of the mPFC promotes anxiety by the activation of GABAergic intermediate inhibitory neurons(IINs).In contrast,a 5-HT_(3)R-induced GABA“disinhibition”mechanism in the infralimbic area of the mPFC and the ventral HIP produces anxiolytic effects.5-HT_(2)R-mediated regulation of anxiety reactions are also activated by 5-HT_(3)R-activated 5-HT release in the HIP and PAG.This provides a theoretical basis for the treatment of anxiety disorders or the production of anxiolytic drugs by targeting 5-HT_(3)Rs.However,given the circuit specific modulation of 5-HT_(3)Rs on emotion,systemic use of 5-HT_(3)R agonism or antagonism alone seems unlikely to remedy anxiety,which deeply hinders the current clinical application of 5-HT_(3)R drugs.Therefore,the exploitation of circuit targeting methods or a combined drug strategy might be a useful developmental approach in the future.
基金Supported by National Natural Science Foundation of China, No. 30270607
文摘AIM： To delineate the mechanisms of renal vasoconstriction in hepatorenal syndrome （HRS）, we investigated the expression of type I inositol 1, 4, 5-triphosphate receptors （IP3R I） of kidney in mice with fulminant hepatic failure （FHF）. METHODS： FHF was induced by lipopolysaccharide （LPS） in D-galactosamine （GAIN） sensitized BALB/c mice. There were 20 mice in normal saline （NS）-treated group, 20 mice in LPS-treated group, 20 mice in GaIN- treated group, and 60 mice in GalN/LPS-treated group （FHF group）. Liver and kidney tissues were obtained at 2, 6, and 9 h after administration. The liver and kidney specimens were stained with hematoxylin-eosin for studying morphological changes under light microscope. The expression of IP3R I in kidney tissue was tested by immunohistochemistry, Western blot and reverse transcription （RT）-PCR. RESULTS： Kidney tissues were morphologically normal at all time points in all groups. IP3R I proteins were found localized in the plasma region of glomerular mesangial cells （GMC） and vascular smooth muscle cells （VSMC） in kidney by immunohistochemical staining. In kidney of mice with FHF at 6 h and 9 h IP3R I staining was upregulated. Results from Western blot demonstrated consistent and significant increment of IP3R I expression in mice with FHF at 6 h and 9 h （t = 3.16, P 〈 0.05; t = 5.43, P 〈 0.01）. Furthermore, we evaluated IP3R I mRNA expression by RT-PCR and observed marked upregulation of IP3R I mRNA in FHF samples at 2 h, 6 h and 9 h compared to controls （t = 2.97, P 〈 0.05; t = 4.42, P 〈 0.01; t = 3.81, P 〈 0.01）. CONCLUSION： The expression of IP3R I protein increased in GMC and renal VSMC of mice with FHF, possibly caused by up-regulation of IP3R I mRNA.
基金Supported by Changsha Science and Technology Program,No.kq2022397Natural Science Foundation of Hunan Province(Departmental Joint Fund),No.2023JJ60440+2 种基金Research Program of Health Commission of Hunan Province,No.202303088786Clinical Medical Research Center for Viral Hepatitis of Hunan Province,No.2023SK4009the Scientific Research Program of FuRong Laboratory,No.2023SK2108.
文摘BACKGROUND C-X-C chemokine receptor type 5(CXCR5)^(+)CD8^(+)T cells represent a unique immune subset with dual roles,functioning as cytotoxic cells in persistent viral infections while promoting B cell responses.Despite their importance,the specific role of CXCR5^(+)CD8^(+)T cells in chronic hepatitis B(CHB),particularly during interferon-alpha(IFN-α)treatment,is not fully understood.This study aims to elucidate the relationship between CXCR5^(+)CD8^(+)T cells and sustained serologic response(SR)in patients undergoing 48 weeks of pegylated IFN-α(peg-IFN-α)treatment for CHB.AIM To elucidate the relationship between CXCR5^(+)CD8^(+)T cells and sustained SR in patients undergoing 48 weeks of peg-IFN-αtreatment for CHB.METHODS This study enrolled 60 patients with hepatitis Be antigen(HBeAg)-positive CHB undergoing 48 weeks of peg-IFN-αtreatment.Participants were assessed for eligibility based on criteria such as persistent HBsAg-positive status for at least six months,HBeAb-negative,hepatitis B virus DNA levels exceeding 2×10^(4) copies/mL,and alanine aminotransferase(ALT)levels between 2 and 10 times the upper limit of normal.Blood samples were collected at baseline and at weeks 12,24,48,and a 24-week treatment-free follow-up(week 72)to measure serum interleukin(IL)-21 concentration via ELISA and to analyze CXCR5 and programmed death-ligand 1(PD-L1)expression on CD8^(+)T cells by flow cytometry,CXCR5 is a chemokine receptor that directs immune cells to specific tissues,while PD-L1 is a protein that regulates immune responses by inhibiting T cell activity.RESULTS Patients with CHB exhibited significantly lower levels of circulating CXCR5^(+)CD8^(+)T cells compared to healthy controls(P<0.01).Notably,CXCR5^(+)CD8^(+)T cells were prominently expressed in patients who achieved sustained SR compared to non-SR(NSR).A significant correlation was observed between CXCR5 and PD-L1 expression(r=-0.189,P=0.002).However,there was no significant correlation between serum IL-21 levels and CXCR5+CD8+lymphocytes(r=-0.03,P=0.625)or serum ALT levels(r=0.026,P=0.678).CONCLUSION The enhanced expression of CXCR5^(+)CD8^(+)T cells in patients achieving HBeAg seroconversion during IFN-αtreatment suggests that these cells play a crucial role in antiviral immune responses against hepatitis B.This study highlights the potential of CXCR5^(+)CD8^(+)T cells as immune regulators in CHB,which may inform future therapeutic strategies to optimize antiviral treatments.
基金supported by grants from the National Natural Science Foundation of China (81920108016 and 32230041)the Priority Academic Program Development of Jiangsu Higher Education Institutions of Chinathe Chinese Red Cross Foundation National Brain Nutrition Research Fund.
文摘Irritable bowel syndrome(IBS)is a common functional bowel disorder characterized by abdominal pain and visceral hypersensitivity.Reducing visceral hypersensitivity is the key to effectively relieving abdominal pain in IBS.Increasing evidence has confirmed that the thalamic nucleus reuniens(Re)and 5-hydroxytryptamine(5-HT)neurotransmitter system play an important role in the development of colorectal visceral pain,whereas the exact mechanisms remain largely unclear.In this study,we found that high expression of the 5-HT2B receptors in the Re glutamatergic neurons promoted colorectal visceral pain.Specifically,we found that neonatal maternal deprivation(NMD)mice exhibited visceral hyperalgesia and enhanced spontaneous synaptic transmission in the Re brain region.Colorectal distension(CRD)stimulation induced a large amount of c-Fos expression in the Re brain region of NMD mice,predominantly in glutamatergic neurons.Furthermore,optogenetic manipulation of glutamatergic neuronal activity in the Re altered colorectal visceral pain responses in CON and NMD mice.In addition,we demonstrated that 5-HT2B receptor expression on the Re glutamatergic neurons was upregulated and ultimately promoted colorectal visceral pain in NMD mice.These findings suggest a critical role of the 5HT2B receptors on the Re glutamatergic neurons in the regulation of colorectal visceral pain.
文摘The present study aimed at evaluation of prophylactic efficacy and possible mechanisms of asiaticoside （AS） based standardized extract of Centella asiatica （L.） Urban leaves （INDCA） in animal models of migraine. The effects of oral and intranasal （i.n.） pretreatment of INDCA （acute and 7-days subacute） were evaluated against nitroglycerine （NTG, 10 mg·kg^-1, i.p.） and bradykinin （BK, 10 μg, intra-arterial） induced hyperalgesia in rats. Tail flick latencies （from 0 to 240 rain） post-NTG treatment and the number of vocalizations post-BK treatment were recorded as a measure of hyperalgesia. Separate groups of rats for negative （Normal） and positive （sumatriptan, 42 mg.kg ^-1, s.c.） controls were included. The interaction of 1NDCA with selective 5-HT1A, 5-HT1B, and 5-HTI D receptor antagonists （NAN-190, Isamoltane hemifumarate, and BRL-15572 respectively） against NTG-induced hyperalgesia was also evaluated. Acute and sub-acute pre-treatment of INDCA [10 and 30 mg.kg^-1 （oral） and 100 μg/rat （i.n.） showed significant anti-nociception activity, and reversal of the NTG-induced hypera｜gesia and brain 5-HT concentration decline. Oral pre-treatment with INDCA （30 mg·kg ^-1, 7 d） showed significant reduction in the number of vocalization. The anti-nociceptive effects of INDCA were blocked by 5-HTIA and 5-HT1B but not 5-HT1D receptor antagonists. In conclusion, 1NDCA demonstrated promising anti-nociceptive effects in animal models of migraine, probably through 5-HT1A/1B medicated action.
基金supported by the National Natural Science Foundation of China(81573322)the Yunnan Wanren Project(YNWR-QNBJ-2018-061)+1 种基金the Youth Innovation Promotion Association,CAS(2013252)the Program of Yunling Scholarship,the Yunnan Science Fund for Excellent Young Scholars(2019FI017)。
文摘Uncariae Ramulus Cum Uncis(Gou-Teng),the dried hook-bearing stems of several Uncaria plants(Rubiaceae),is a wellknown herbal medicine in China.The clinical application of Gou-Teng is bewildered for the morphological and chemical similarity between diferent species.In order to discern their chemical and biological diference,an ultra-fast liquid chromatography equipped with ion trap time-of-fight mass spectrometry(UFLC-IT/TOF-MS)combining with melatonin(MT1 and MT2)and 5-hydroxytryptamine(5-HT1A and 5-HT2C)receptors agonistic assay in vitro was conducted on seven Uncaria species.As a result,57 compounds including 35 indole alkaloids,ten favonoids,fve triterpenoids,fve chlorogenic analogues,and two other compounds were characterized based on their MS/MS patterns and UV absorptions.Specifcally,cadambine-type and corynanthein-type alkaloids were exclusively present in U.rhynchophylla and U.scandens,whereas corynoxine-type alkaloids were commonly detected in all the seven Uncaria plants.Three Uncaria species,U.rhynchophylla,U.macrophylla,and U.yunnanensis showed obviously agnostic activity on four neurotransmitter receptors(MT1,MT2,5-HT1A,and 5-HT_(2C)).This frst-time UFLCMS-IT-TOF analyses integrated with biological assay on seven Uncaria plants will provide scientifc viewpoints for the clinical application of Gou-Teng.
基金supported by National Natural Science Foundation of China(No.30271500)Science and Tech-nology Research Project Fund from the Department of Edu-cation of Hubei Province of China(No.B20115101)
文摘This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique. The results showed that: (1) The majority of examined neurons (78.70%) were sensitive to 5-HT (3–300 μmol/L). 5-HT induced inward currents in a concentration-dependent manner and the currents were blocked by ICS 205-930 (1 μmol/L), a selective antagonist of the 5-HT3 receptor; (2) Pre-application of WIN55,212-2 (0.01–1 μmol/L) significantly inhibited I5-HT3 reversibly in concentration-dependent and voltage-independent manners. The concentra-tion-response curve of 5-HT3 receptor was shifted downward by WIN55,212-2 without any change of the threshold value. The EC50 values of two curves were very close (17.5±4.5) mmol/L vs. (15.2±4.5) mmol/L and WIN55,212-2 decreased the maximal amplitude of I5-HT3 by (48.65±4.15)%; (3) Neither AM281, a selective CB1 receptor antagonist, nor AM630, a selective CB2 receptor antagonist reversed the inhibition of I5-HT3 by WIN55,212-2; (4) When WIN55,212-2 was given from 15 to 120 s before 5-HT application, inhibitory effect was gradually increased and the maximal inhibition took place at 90 s, and the inhibition remained at the same level after 90 s. We are led to concluded that-WIN55,212-2 inhibited I5-HT3 significantly and neither CB1 receptor antagonist nor CB2 receptor antagonist could reverse the inhibition of I5-HT3 by WIN55,212-2. Moreover, WIN55,212-2 is not an open channel blocker (OCB) of 5-HT3 receptor. WIN55,212-2 significantly inhibited 5-HT-activated currents in a non-competitive manner. The inhibition of I5-HT3 by WIN55,212-2 is probably new one of peripheral analgesic mechanisms of WIN55,212-2, but the mechanism by which WIN55,212-2 inhibits I5-HT3 warrants further investigation.
基金Supported by National Natural Science Foundation of China,No.81800771 and No.81300702.
文摘BACKGROUND The global prevalence of metabolic dysfunction-associated steatotic liver disease(MASLD)has continued to increase annually.Recent studies have indicated that inhibition of metabotropic glutamate receptor 5(mGluR5)may alleviate hepatic steatosis.However,the precise mechanism warrants further exploration.AIM To investigate the potential mechanism by which mGluR5 attenuates hepatocyte steatosis in vitro and in vivo.METHODS Free fatty acids(FFAs)-stimulated HepG2 cells were treated with the mGluR5 antagonist MPEP and the mGluR5 agonist CHPG.Oil Red O staining and a triglyceride assay kit were used to evaluate lipid content.Western blot analysis was conducted to detect the expression of the autophagy-associated proteins p62 and LC3-II,as well as the expression of the key signaling molecules AMPK and ULK1,in the treated cells.To further elucidate the contributions of autophagy and AMPK,we used chloroquine(CQ)to inhibit autophagy and compound C(CC)to inhibit AMPK activity.In parallel,wild-type mice and mGluR5 knockout(KO)mice fed a normal chow diet or a high-fat diet(HFD)were used to evaluate the effect of mGluR5 inhibition in vivo.RESULTS mGluR5 inhibition by MPEP attenuated hepatocellular steatosis and increased LC3-II and p62 protein expression.The autophagy inhibitor CQ reversed the effects of MPEP.In addition,MPEP promoted AMPK and ULK1 expression in HepG2 cells exposed to FFAs.MPEP treatment led to the nuclear translocation of transcription factor EB,which is known to promote p62 expression.This effect was negated by the AMPK inhibitor CC.mGluR5 KO mice presented reduced body weight,improved glucose tolerance and reduced hyperlipidemia when fed a HFD.Additionally,the livers of HFD-fed mGluR5 KO mice presented increases in LC3-II and p62.CONCLUSION Our results suggest that mGluR5 inhibition promoted autophagy and reduced hepatocyte steatosis through activation of the AMPK signaling pathway.These findings reveal a new functional mechanism of mGluR5 as a target in the treatment of MASLD.
