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
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
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
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
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
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
BACKGROUND N6-methyladenosine(m6A)modification represents the predominant alteration found in eukaryotic messenger RNA and plays a crucial role in the progression of various tumors.However,despite its significance,the...BACKGROUND N6-methyladenosine(m6A)modification represents the predominant alteration found in eukaryotic messenger RNA and plays a crucial role in the progression of various tumors.However,despite its significance,the comprehensive investigation of METTL5,a key m6A methyltransferase,in colorectal cancer(CRC)remains limited.AIM To investigate the role of METTL5 in CRC.METHODS We assessed METTL5 expression levels in clinical samples obtained from CRC patients as well as in CRC cell lines.To elucidate the downstream targets of METTL5,we performed RNA-sequencing analysis coupled with correlation analysis,leading us to identify Toll-like receptor 8(TLR8)as a potential downstream target.In vitro functional assessments of METTL5 and TLR8 were conducted using CCK-8 assays,scratch assays,as well as assays measuring cell migration and invasion.RESULTS Our findings reveal a pronounced upregulation of METTL5 expression in both CRC cells and tissues,which correlated significantly with an unfavorable prognosis.In vitro experiments unequivocally demonstrated the oncogenic role of METTL5,as evidenced by its promotion of CRC cell proliferation,invasion,and migration.Notably,we identified TLR8 as a downstream target of METTL5,and subsequent down-regulation of TLR8 led to a significant inhibition of CRC cell proliferation,invasion,and tumor growth.CONCLUSION The heightened expression of METTL5 in CRC is strongly associated with clinicopathological features and a poor prognosis,thereby underscoring its potential utility as a critical marker for facilitating early diagnosis and prognostication in CRC.展开更多
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 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 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.
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.
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 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.
基金Supported by Natural Science Foundation in Anhui Province of China,No.2008085MH279Key Project of Anhui Translational Medicine Research Institute,No.2022zhyx-B08.
文摘BACKGROUND N6-methyladenosine(m6A)modification represents the predominant alteration found in eukaryotic messenger RNA and plays a crucial role in the progression of various tumors.However,despite its significance,the comprehensive investigation of METTL5,a key m6A methyltransferase,in colorectal cancer(CRC)remains limited.AIM To investigate the role of METTL5 in CRC.METHODS We assessed METTL5 expression levels in clinical samples obtained from CRC patients as well as in CRC cell lines.To elucidate the downstream targets of METTL5,we performed RNA-sequencing analysis coupled with correlation analysis,leading us to identify Toll-like receptor 8(TLR8)as a potential downstream target.In vitro functional assessments of METTL5 and TLR8 were conducted using CCK-8 assays,scratch assays,as well as assays measuring cell migration and invasion.RESULTS Our findings reveal a pronounced upregulation of METTL5 expression in both CRC cells and tissues,which correlated significantly with an unfavorable prognosis.In vitro experiments unequivocally demonstrated the oncogenic role of METTL5,as evidenced by its promotion of CRC cell proliferation,invasion,and migration.Notably,we identified TLR8 as a downstream target of METTL5,and subsequent down-regulation of TLR8 led to a significant inhibition of CRC cell proliferation,invasion,and tumor growth.CONCLUSION The heightened expression of METTL5 in CRC is strongly associated with clinicopathological features and a poor prognosis,thereby underscoring its potential utility as a critical marker for facilitating early diagnosis and prognostication in CRC.
