AIM To investigate the role of calmodulin-dependent protein kinase Ⅱ(Ca MKⅡ) in colon cancer growth,migration and invasion.METHODS Ca MKⅡ expression in colon cancer and paracancerous tissues was evaluated via immun...AIM To investigate the role of calmodulin-dependent protein kinase Ⅱ(Ca MKⅡ) in colon cancer growth,migration and invasion.METHODS Ca MKⅡ expression in colon cancer and paracancerous tissues was evaluated via immunochemistry. Transcriptional and posttranscriptional levels of Ca MKⅡin tissue samples and MMP2,MMP9 and TIMP-1 expression in the human colon cancer cell line HCT116 were assessed by q RTPCR and western blot. Cell proliferation was detected with the MTT assay. Cancer cell migration and invasion were investigated with the Transwell culture system and woundhealing assay.RESULTS We first demonstrated that CaMK Ⅱ was ove rexpressed in human colon cancers and was associated with cancer differentiation. In the human colon cancer cell line HCT116,the Ca MKII-specific inhibitor KN93,but not its inactive analogue KN92,decreased cancer cell proliferation. Furthermore,KN93 also significantly prohibited HCT116 cell migration and invasion. The specific inhibition of ERK1/2 or p38 decreased the proliferation and migration of colon cancer cells.CONCLUSION Our findings highlight Ca MKⅡ as a potential critical mediator in human colon tumor development and metastasis.展开更多
In this study, primary cultured cerebral cortical neurons of Sprague-Dawley neonatal rats were treated with 0.25, 0.5, and 1.0 μM calmodulin-dependent protein kinase II inhibitor KN-93 after 50 μM N-methyI-D-asparti...In this study, primary cultured cerebral cortical neurons of Sprague-Dawley neonatal rats were treated with 0.25, 0.5, and 1.0 μM calmodulin-dependent protein kinase II inhibitor KN-93 after 50 μM N-methyI-D-aspartic acid-induced injury. Results showed that, compared with N-methyi-D- aspartic acid-induced injury neurons, the activity of cells markedly increased, apoptosis was significantly reduced, leakage of lactate dehydrogenase decreased, and intracellular Ca2＋ concentrations in neurons reduced after KN-93 treatment. The expression of caspase-3, phosphorylated calmodulin-dependent protein kinase II and total calmodulin-dependent protein kinase II protein decreased after KN-93 treatment. And the effect was apparent at a dose of 1.0 pM KN-93. Experimental findings suggest that KN-93 can induce a dose-dependent neuroprotective effect, and that the underlying mechanism may be related to the down-regulation of caspase-3 and calmodulin- dependent protein kinase II expression.展开更多
Septic encephalopathy is a frequent complication of sepsis,but there are few studies examining the role of micro RNAs（mi Rs） in its pathogenesis.In this study,a mi R-219 mimic was transfected into rat hippocampal ne...Septic encephalopathy is a frequent complication of sepsis,but there are few studies examining the role of micro RNAs（mi Rs） in its pathogenesis.In this study,a mi R-219 mimic was transfected into rat hippocampal neurons to model mi R-219 overexpression.A protective effect of mi R-219 was observed for glutamate-induced neurotoxicity of rat hippocampal neurons,and an underlying mechanism involving calmodulin-dependent protein kinase II γ（Ca MKIIγ） was demonstrated.mi R-219 and Ca MKIIγ m RNA expression induced by glutamate in hippocampal neurons was determined by quantitative real-time reverse transcription-polymerase chain reaction（q RT-PCR）.After neurons were transfected with mi R-219 mimic,effects on cell viability and apoptosis were measured by 3-（4,5-dimethylthiazolyl-2）-2,5-diphenyltetrazolium bromide（MTT） assay and flow cytometry.In addition,a luciferase reporter gene system was used to confirm Ca MKIIγ as a target gene of mi R-219.Western blot assay and rescue experiments were also utilized to detect Ca MKIIγ expression and further verify that mi R-219 in hippocampal neurons exerted its effect through regulation of Ca MKIIγ.MTT assay and q RT-PCR results revealed obvious decreases in cell viability and mi R-219 expression after glutamate stimulation,while Ca MKIIγ m RNA expression was increased.MTT,flow cytometry,and caspase-3 activity assays showed that mi R-219 overexpression could elevate glutamate-induced cell viability,and reduce cell apoptosis and caspase-3 activity.Moreover,luciferase Ca MKIIγ-reporter activity was remarkably decreased by co-transfection with mi R-219 mimic,and the results of a rescue experiment showed that Ca MKIIγ overexpression could reverse the biological effects of mi R-219.Collectively,these findings verify that mi R-219 expression was decreased in glutamate-induced neurons,Ca MKIIγ was a target gene of mi R-219,and mi R-219 alleviated glutamate-induced neuronal excitotoxicity by negatively controlling Ca MKIIγ expression.展开更多
Cardiac hypertrophy is an independent risk factor for sudden cardiac death in clinical settings and the incidence of sudden cardiac death and ventricular arrhythmias are closely related.The aim of this study was to de...Cardiac hypertrophy is an independent risk factor for sudden cardiac death in clinical settings and the incidence of sudden cardiac death and ventricular arrhythmias are closely related.The aim of this study was to determine the effects of the calmodulin-dependent protein kinase(CaMK) Ⅱ inhibitor,KN-93,on L-type calcium current(I Ca,L) and early after-depolarizations(EADs) in hypertrophic cardiomyocytes.A rabbit model of myocardial hypertrophy was constructed through abdominal aortic coarctation(LVH group).The control group(sham group) received a sham operation,in which the abdominal aortic was dissected but not coarcted.Eight weeks later,the degree of left ventricular hypertrophy(LVH) was evaluated using echocardiography.Individual cardiomyocyte was isolated through collagenase digestion.Action potentials(APs) and I Ca,L were recorded using the perforated patch clamp technique.APs were recorded under current clamp conditions and I Ca,L was recorded under voltage clamp conditions.The incidence of EADs and I ca,L in the hypertrophic cardiomyocytes were observed under the conditions of low potassium(2 mmol/L),low magnesium(0.25 mmol/L) Tyrode’s solution perfusion,and slow frequency(0.25-0.5 Hz) electrical stimulation.The incidence of EADs and I ca,L in the hypertrophic cardiomyocytes were also evaluated after treatment with different concentrations of KN-92(KN-92 group) and KN-93(KN-93 group).Eight weeks later,the model was successfully established.Under the conditions of low potassium,low magnesium Tyrode’s solution perfusion,and slow frequency electrical stimulation,the incidence of EADs was 0/12,11/12,10/12,and 5/12 in sham group,LVH group,KN-92 group(0.5 μmol/L),and KN-93 group(0.5 μmol/L),respectively.When the drug concentration was increased to 1 μmol/L in KN-92 group and KN-93 group,the incidence of EADs was 10/12 and 2/12,respectively.At 0 mV,the current density was 6.7±1.0 and 6.3±0.7 PA·PF-1 in LVH group and sham group,respectively(P>0.05,n=12).When the drug concentration was 0.5 μmol/L in KN-92 and KN-93 groups,the peak I Ca,L at 0 mV was decreased by(9.4±2.8)% and(10.5±3.0)% in the hypertrophic cardiomyocytes of the two groups,respectively(P>0.05,n=12).When the drug concentration was increased to 1 μmol/L,the peak I Ca,L values were lowered by(13.4±3.7)% and(40±4.9)%,respectively(P<0.01,n=12).KN-93,a specific inhibitor of CaMKII,can effectively inhibit the occurrence of EADs in hypertrophic cardiomyocytes partially by suppressing I Ca,L,which may be the main action mechanism of KN-93 antagonizing the occurrence of ventricular arrhythmias in hypertrophic myocardium.展开更多
Metabolic syndrome is a pre-diabetic state characterized by several biochemical and physiological alterations,including insulin resistance,visceral fat accumulation,and dyslipidemias,which increase the risk for develo...Metabolic syndrome is a pre-diabetic state characterized by several biochemical and physiological alterations,including insulin resistance,visceral fat accumulation,and dyslipidemias,which increase the risk for developing cardiovascular disease.Metabolic syndrome is associated with augmented sympathetic tone,which could account for the etiology of pre-diabetic cardiomyopathy.This review summarizes the current knowledge of the pathophysiological consequences of enhanced and sustainedβ-adrenergic response in pre-diabetes,focusing on cardiac dysfunction reported in diet-induced experimental models of pre-diabetic cardiomyopathy.The research reviewed indicates that both protein kinase A and Ca^(2+)/calmodulin-dependent protein kinase Ⅱ play important roles in functional responses mediated byβ1-adrenoceptors;therefore,alterations in the expression or function of these kinases can be deleterious.This review also outlines recent information on the role of protein kinase A and Ca^(2+)/calmodulin-dependent protein kinase Ⅱ in abnormal Ca^(2+)handling by cardiomyocytes from diet-induced models of pre-diabetic cardiomyopathy.展开更多
OBJECTIVE To determine the functional role of hydrogen sulfide(H_2S) in protecting against mitochondrial dysfunction in heart failure through the inhibition of Ca^(2+)/calmodulin-dependent protein kinaseⅡ(Ca MKⅡ) us...OBJECTIVE To determine the functional role of hydrogen sulfide(H_2S) in protecting against mitochondrial dysfunction in heart failure through the inhibition of Ca^(2+)/calmodulin-dependent protein kinaseⅡ(Ca MKⅡ) using wild type and CSE knockout mouse models.METHODS Continuous subcutaneous injection isoprenaline(7.5 mg·kg^(-1) per day),once a day for 4 weeks to induce heart failure in male C57BL/6(6-8 weeks old) mice and CSE-/-mice.150 μmol·L^(-1) H_2O_2 was used to induce oxidative stress in H9c2 cells.Echocardiograph was used to detect cardiac parameters.H&E stain and Masson stain was to observation histopathological changes.Western blot was used to detect protein expression and activity.The si RNA was used to silence protein expression.HPLC was used to detect H_2S level.Biotin assay was used to detect the level of S-sulfhydration protein.RESULTS Treatment with S-propyl-L-cysteine(SPRC) or sodium hydrosulfide(Na HS),modulators of blood H_2S levels,attenuated the development of heart failure in animals,reduced lipid peroxidation,and preserved mitochondrial function.The inhibition Ca MKⅡ phosphorylation by SPRC and Na HS as demonstrated using both in vivo and in vitro models corresponded with the cardioprotective effects of these compounds.Interestingly,Ca MKⅡ activity was found to be elevated in CSE-/-mice as compared to wild type animals and the phosphorylation status of Ca MK Ⅱ appeared to relate to the severity of heart failure.Importantly,in wild type mice SPRC was found to promote S-sulfhydration of Ca MKⅡ leading to reduced activity of this protein however,in CSE-/-mice S-sulfhydration was abolished following SPRC treatment.CONCLUSION A novel mechanism depicting a role of S-sulfhydration in the regulation of Ca MKⅡ is presented.SPRC mediated S-sulfhydration of Ca MKⅡ was found to inhibit Ca MKⅡ activity and to preserve cardiovascular homeostasis.展开更多
Using nystatin-perforated whole-cell recording configuration, the modulatory effect of N-methyl-D-aspartate (NMDA) on γ-aminobutyric acid (GABA)-activated whole-cell currents was investigated in neurons freshly disso...Using nystatin-perforated whole-cell recording configuration, the modulatory effect of N-methyl-D-aspartate (NMDA) on γ-aminobutyric acid (GABA)-activated whole-cell currents was investigated in neurons freshly dissociated from the rat sacral dorsal commissural nucleus (SDCN). The results showed that: (i) NMDA suppressed GABA- and muscimol (Mus)-activated currents (IGABA and IMUS), respectively in the Mg2+-free external solution containing 1 μmol/L glycine at a holding potential (VH) of -40 mV in SDCN neurons. The selective NMDA receptor antagonist, D-2-amino-5-phosphonovaleric acid (APV, 100 μmol/L), inhibited the NMDA-evoked currents and blocked the NMDA-induced suppression of IGABA; (ii) when the neurons were incubated in a Ca2+-free bath or pre-loaded with a membrane-permeable Ca2+ chelator, BAPTA AM (10 nmol/L), the inhibitory effect of NMDA on IGABA disappeared. Cd2+ (10 μmol/L) or La3+(30 μmol/L), the non-selective blockers of voltage-dependent calcium channels, did not affect the suppression of IGABA by NMDA application; (iii) the suppression of IGABA by NMDA was inhibited by KN-62, a cal-cium/calmodulin-dependent protein kinase II (CaMKII) inhibitor. These results indicated that the inhibition of GABA response by NMDA is Ca2+-dependent and CaMKII is involved in the process of the Ca2+-dependent inhibition.展开更多
Objective:The aim of this study was to investigate the protective effects of ginsenoside Rb1 and assess whether these protective effects are related to calcium/calmodulin-dependent protein kinaseⅡ(Ca MKⅡ).Methods:A ...Objective:The aim of this study was to investigate the protective effects of ginsenoside Rb1 and assess whether these protective effects are related to calcium/calmodulin-dependent protein kinaseⅡ(Ca MKⅡ).Methods:A myocardial ischemia(IS)rat.model and a myocardial H9 C2 cell hypoxia model were established.MI was induced by occluding the left anterior descending artery for 120 min.Ginsenoside Rb1(10 mg/kg)was administered 30 min before ischemia induction,and the treatment continued for 7 days.Results:In the rat IS injury model,ginsenoside Rb1 reduced myocardial infarct size,mean left ventricular diastolic pressure,incidence of arrhythmia,and levels of serum creatine kinase,lactate dehydrogenase,and malondialdehyde.However,the mean left ventricular systolic pressure,and maximal rising and falling rates of ventricular pressure(±dp/dtmax)increased.In the myocardial H9 C2 cell hypoxia model,ginsenoside Rb1 reduced intracellular calcium concentrations([Ca2+]i)during hypoxia,and markedly reversed the hypoxia-induced decrease in cell survival.Ginsenoside Rb1 was involved in the downregulation of CaMKⅡand the ryanodine receptor,as well as hypoxia-induced H9 C2 cell survival.Conclusion:The findings of the present study suggest that ginsenoside Rb1 attenuates MI injury in rats,partially through the downregulation of CaMKⅡexpression.展开更多
A calmodulin-dependent protein kinase (MCK1) appeared important in regulating flowering in tobacco. The expression of modified MCK1 that lacks the C-terminal including calmodulin-binding domain upsets the flowering de...A calmodulin-dependent protein kinase (MCK1) appeared important in regulating flowering in tobacco. The expression of modified MCK1 that lacks the C-terminal including calmodulin-binding domain upsets the flowering developmental program, leading to the abortion of flower primordia initiated on the main axis of the plant and, as well, caused the prolongation of the vegetative phase in axillary buds. The abortion process of flowers began first in the developing anthers and subsequently the entire flower senesces. In axillary buds the prolonged vegetative phase was characterized by atypical elongated, narrow, twisted leaves. These results suggested a role for calmodulin-dependent protein kinase homologs in mediating flowering.展开更多
Many of the effects of Ca^2＋ signaling are mediated through the Ca^2＋/calmodulin complex and its acceptors, the Ca^2＋/calmodulin-dependent protein kinases, including PSKHI. Studies of the proteins involved in the c...Many of the effects of Ca^2＋ signaling are mediated through the Ca^2＋/calmodulin complex and its acceptors, the Ca^2＋/calmodulin-dependent protein kinases, including PSKHI. Studies of the proteins involved in the calcium metabolism in oysters will help elucidate the pearl formation mechanism. This paper describes a full-length PSKH1 cDNA isolated from pearl oyster Pinctada fucata. Oyster PSKH1 shares 65% homology with human PSKH1 and 48% similarity with rat CaM kinase I in the amino acid sequence, and contains a calmodulin-binding domain. The results of semi-quantitative reverse transcription-polymerase chain reaction and in situ hybridization revealed that oyster PSKH1 mRNA is highly expressed in the outer epithelial cells of the mantle pallial and in the gill epithelial cells. These studies provide important information describing the complex Ca^2＋ signaling mechanism in oyster calcium metabolism.展开更多
Background:Glioma is the most common tumor of the central nervous system with a poor prognosis.This study aims to explore the role of calcium/calmodulin-dependent protein kinase IIβ(CAMK2B)in regulating the malignant...Background:Glioma is the most common tumor of the central nervous system with a poor prognosis.This study aims to explore the role of calcium/calmodulin-dependent protein kinase IIβ(CAMK2B)in regulating the malignant progression of glioma cells,as well as the molecular mechanisms underlying these malignant behaviors.Methods:The correlation between CAMK2B expression in gliomas and patient prognosis was analyzed using immunohistochemistry,quantitative reverse transcription polymerase chain reaction(qRT-PCR),and western blot.Furthermore,the study explored the role of CAMK2B in glioma cell proliferation,invasion,and migration using cell counting kit-8(CCK-8),5-Ethynyl-2′-deoxyuridine(EdU),wound healing,transwell,and in vivo tumor xenograft assays.Result:Patients with high CAMK2B expression exhibited significantly better prognostic outcomes compared to those with low expression levels.Furthermore,CAMK2B expression was significantly lower in glioma tissues and cells compared to both normal brain tissue and human astrocyte cell lines.Notably,overexpression of CAMK2B in glioma cells led to an approximate 40%reduction in proliferative capacity and a 60–70%decrease in invasive and migratory abilities,compared to control glioma cells.These differences were statistically significant at p<0.05.Conversely,knockdown of CAMK2B using siRNA-CAMK2B significantly enhanced the proliferative,invasive,and migratory capabilities of glioma cells in both in vitro and in vivo settings,enhancing these abilities by 1.5 to 3 times.Notably,these effects were reversed through the application of the Rat Sarcoma viral oncogene homolog(Ras)pathway inhibitor,Salirasib.Western blot analysis revealed that knockdown of CAMK2B led to activation of the Ras/Rapidly Accelerated Fibrosarcoma(Raf)/Mitogen-activated protein kinase kinase(MEK)/Extracellular signal-regulated kinase(ERK)signaling pathway in glioma cell lines,whereas overexpression of CAMK2B resulted in the suppression of this pathway.Conclusion:CAMK2B inhibits glioma proliferation,invasion,andmigration through the Ras/Raf/MEK/ERK signaling pathway.展开更多
Protein-protein interactions represent an important mechanism for posttranslational modifications of protein expression and function.In brain cells,surface-expressed and membrane-bound neurotransmitter receptors are c...Protein-protein interactions represent an important mechanism for posttranslational modifications of protein expression and function.In brain cells,surface-expressed and membrane-bound neurotransmitter receptors are common proteins that undergo dynamic protein-protein interactions between their intracellular domains and submembranous regulatory proteins.Recently,the Gφi/o -coupled muscarinic M4 receptor（M4R）has been revealed to be one of these receptors.Through direct interaction with the intracellular loops or C-terminal tails of M4Rs,M4R interacting proteins（M4RIPs）vigorously regulate the efficacy of M4R signaling.A synapse-enriched protein kinase,Ca2＋/calmodulin-dependent protein kinase II （CaMKII）,exemplifies a prototype model of M4RIPs,and is capable of binding to the second intracellular loop of M4Rs. Through an activity-and phosphorylation-dependent mechanism,CaMKII potentiates the M4R/Gφi/o-mediated inhibition of M4R efficacy in inhibiting adenylyl cyclase and cAMP production.In striatal neurons where M4Rs are most abundantly expressed,M4RIPs dynamically control M4R activity to maintain a proper cholinergic tone in these neurons.This is critical for maintaining the acetylcholine-dopamine balance in the basal ganglia,which determines the behavioral responsiveness to dopamine stimulation by psychostimulants.展开更多
In the present study, we examined the analgesic effect of repeated electroacupuncture at bilateral Zusanfi （ST36） and Yanglingquan （GB34） once a day for 14 consecutive days in a rat model of chronic sciatic nerve ...In the present study, we examined the analgesic effect of repeated electroacupuncture at bilateral Zusanfi （ST36） and Yanglingquan （GB34） once a day for 14 consecutive days in a rat model of chronic sciatic nerve constriction injury-induced neuropathic pain. In addition, concomitant changes in calcium/calmodulin-dependent protein kinase II expression and synaptic ultrastructure of neurons in the hippocampal CA3 region were examined. The thermal pain threshold （paw withdrawal latency） was increased significantly in both groups at 2 weeks after electroacupuncture intervention compared with 2 days of electroacupuncture. In ovariectomized rats with chronic constriction injury, the analgesic effect was significantly reduced. Electroacupuncture for 2 weeks significantly diminished the injury-induced increase in synaptJc cleft width and thinning of the postsynaptJc density, and it significantly suppressed the down-regulation of intracellular calcium/ calmodulin-dependent protein kinase II expression in the hippocampal CA3 region. Repeated electroacupuncture intervention had a cumulative analgesic effect on injury-induced neuropathic pain reactions, and it led to synaptic remodeling of hippocampal neurons and upregulated calcium/calmodulin-dependent protein kJnase II expression in the hippocampal CA3 region.展开更多
Accumulating evidence indicates that inhalation anesthetics induce or increase the risk of cognitive impairment. GLYX-13（rapastinel） acts on the glycine site of N-methyl-D-aspartate receptors（NMDARs） and has been ...Accumulating evidence indicates that inhalation anesthetics induce or increase the risk of cognitive impairment. GLYX-13（rapastinel） acts on the glycine site of N-methyl-D-aspartate receptors（NMDARs） and has been shown to enhance hippocampus-dependent learning and memory function. However, the mechanisms by which GLYX-13 affects learning and memory function are still unclear. In this study, we investigated these mechanisms in a mouse model of long-term anesthesia exposure. Mice were intravenously administered 1 mg/kg GLYX-13 at 2 hours before isoflurane exposure（1.5% for 6 hours）. Cognitive function was assessed using the contextual fear conditioning test and the novel object recognition test. The mRNA expression and phosphorylated protein levels of NMDAR pathway components, N-methyl-D-aspartate receptor subunit 2B（NR2B）-Ca2+/calmodulin dependent protein kinase II（CaMKII）-cyclic adenosine monophosphate response element binding protein（CREB）, in the hippocampus were evaluated by quantitative RT-PCR and western blot assay. Pretreatment with GLYX-13 ameliorated isoflurane exposure-induced cognitive impairment and restored NR2B, CaMKII and CREB mRNA and phosphorylated protein levels. Intracerebroventricular injection of KN93, a selective CaMKII inhibitor, significantly diminished the effect of GLYX-13 on cognitive function and NR2B, CaMKII and CREB levels in the hippocampus. Taken together, our findings suggest that GLYX-13 pretreatment alleviates isoflurane-induced cognitive dysfunction by protecting against perturbation of the NR2B/CaMKII/CREB signaling pathway in the hippocampus. Therefore, GLYX-13 may have therapeutic potential for the treatment of anesthesia-induced cognitive dysfunction. This study was approved by the Experimental Animal Ethics Committee of Drum Tower Hospital affiliated to the Medical College of Nanjing University, China（approval No. 20171102） on November 20, 2017.展开更多
Objective:Cardiac hypertrophy is an adaptive reaction of the heart against cardiac overloading,but continuous cardiac hypertrophy can lead to cardiac remodeling and heart failure.Cardiac hypertrophy is mostly consider...Objective:Cardiac hypertrophy is an adaptive reaction of the heart against cardiac overloading,but continuous cardiac hypertrophy can lead to cardiac remodeling and heart failure.Cardiac hypertrophy is mostly considered reversible,and recent studies have indicated that decorin not only prevents cardiac fibrosis associated with hypertension,but also achieves therapeutic effects by blocking fibrosis-related signaling pathways.However,the mechanism of action of decorin remains unknown and unconfirmed.Methods:We determined the degree of myocardial hypertrophy by measuring the ratios of the heart weight/body weight and left ventricular weight/body weight,histological analysis and immunohistochemistry.Western blotting was performed to detect the expression levels of CaMKⅡ,p-CaMKⅡ and MEF-2 in the heart.Results:Our results confirmed that decorin can regulate the CaMKⅡ/MEF-2 signaling pathway,with inhibition thereof being similar to that of decorin in reducing cardiac hypertrophy.Conclusion:Taken together,the results of the present study showed that decorin induced cardiac hypertrophy by regulating the CaMKⅡ/MEF-2 signaling pathway in vivo,revealing a new therapeutic approach for the prevention of cardiac hypertrophy.展开更多
Membrane depolarization induces the release of the serine proteinase tissue-type plasminogen activator（t PA） from the presynaptic terminal of cerebral cortical neurons.Once in the synaptic cleft this t PA promotes t...Membrane depolarization induces the release of the serine proteinase tissue-type plasminogen activator（t PA） from the presynaptic terminal of cerebral cortical neurons.Once in the synaptic cleft this t PA promotes the exocytosis and subsequent endocytic retrieval of glutamate-containing synaptic vesicles,and regulates the postsynaptic response to the presynaptic release of glutamate.Indeed,t PA has a bidirectional effect on the composition of the postsynaptic density（PSD） that does not require plasmin generation or the presynaptic release of glutamate,but varies according to the baseline level of neuronal activity.Hence,in inactive neurons t PA induces phosphorylation and accumulation in the PSD of the Ca^（2＋）/calmodulin-dependent protein kinase IIα（pCa MKIIα）,followed by pCa MKIIα-induced phosphorylation and synaptic recruitment of Glu R1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid（AMPA） receptors.In contrast,in active neurons with increased levels of pCa MKIIα in the PSD t PA induces pCa MKIIα and p Glu R1 dephosphorylation and their subsequent removal from the PSD.These effects require active synaptic N-methyl-D-aspartate（NMDA） receptors and cyclin-dependent kinase 5（Cdk5）-induced phosphorylation of the protein phosphatase 1（PP1） at T320.These data indicate that t PA is a homeostatic regulator of the postsynaptic response of cerebral cortical neurons to the presynaptic release of glutamate via bidirectional regulation of the pCa MKIIα/PP1 switch in the PSD.展开更多
Intramuscular fat （IMF） content in chickens significantly contributes to meat quality. The main objective of this study was to assess the expression of calcineudn （CAN） and Ca^2＋/calmodutin-dependent protein kina...Intramuscular fat （IMF） content in chickens significantly contributes to meat quality. The main objective of this study was to assess the expression of calcineudn （CAN） and Ca^2＋/calmodutin-dependent protein kinase （CAME） in lipogene- sis in chicken muscle. The chickens were slaughtered and sampled at the ages of 4, 8, and 16 weeks, respectively. IMF content and the expression of CaN subunits and CaMK isoforms were measured in thigh muscle tissue. The results showed that the IMF contents were higher in chickens at the age of 16 weeks compared with those in chickens at the ages of 4 and 8 weeks （P〈0.05）. The expression levels of fatty acid synthase （FAS） and fatty acid translocase CD36 （FAT/CD36） mRNA in 16-week-old chickens were all significantly up-regulated compared with those in 4-week-old chickens （P〈0.05）. The mRNA levels of CaNB and CaMK IV in 16-week-old chickens were significantly lower than those in 4-week-old chickens （P〈0.05）. But the CaMK II mRNA levels in 16-week-old chickens were significantly higher than those in 4-week-old chickens （P〈0.05）. To investigate the roles of CaMK and CaN in adipogenesis, SV cells were incubated in standard adipogenesis medium for 24 h and treated with specific inhibitor of CaMK and CaN. The ex- pressions of CCAAT/enhancer binding protein β（C/EBPJ3）, sterol regulatory element- binding protein 1 （SREBP1） and peroxisome proliferation-activated receptor ）, （PPARy） were dramatically enhanced by CsA and CaN inhibitor （P〈0.05）. KN93, a CaMK Ⅱ inhibitor, dramatically repressed the expression of those lipogenic genes （P〈0.05）. All the results above indicated that CaN and CaMK had different effects on adipogenesis in the muscle of chickens.展开更多
Background:As many as 80%of patients with neuropsychiatric lupus develop cognitive dysfunction,yet its diagnosis and treatment are underdeveloped.Objective:This study aimed to investigate the therapeutic effects and u...Background:As many as 80%of patients with neuropsychiatric lupus develop cognitive dysfunction,yet its diagnosis and treatment are underdeveloped.Objective:This study aimed to investigate the therapeutic effects and underlying mechanisms of Liuwei Dihuang Pill on cognitive dysfunction in mice with neuropsychiatric lupus,utilizing research involving the hippocampal neuronal cell line HT22.Methods:A combination of animal and cellular experiments was employed to investigate the preventive treatment of systemic lupus erythematosus associated with cognitive dysfunction using Liuwei dihuang pill.BALB/c mice were induced with imiquimod and pristane,followed by oral administration of Liuwei Dihuang Pill.Behavioral alterations,levels of anti-dsDNA and anti-ribosomal P protein antibodies,hippocampal indices,changes in hip-pocampal tissue and neurons,and levels of NMDARs and CaMKII in the hippocampus were assessed.Lipopolysac-charide was utilized to induce damage in HT22 cells.The efficacy of serum containing Liuwei Dihuang Pill on these cells was evaluated by observing morphological changes,assessing cell viability,and analyzing protein and mRNA content.Results:Treatment with Liuwei dihuang pill significantly improved levels of autoantibodies,urinary protein,behavioral symptoms,nuclear pyknosis,and apoptosis of hippocampal neurons in mice with neuropsychiatric lupus.Furthermore,there was a notable upregulation in the expression levels of NMDARs and CaMKII.Pretreat-ment with serum containing Liuwei Dihuang Pill markedly increased the survival rate of HT22 cells and elevated both protein and mRNA levels of NMDARs and CaMKII compared to the lipopolysaccharide stimulation group.Conclusion:Liuwei dihuang pill has the potential to improve cognitive function of Pritam and imiquimod induce dysfunction in neuropsychiatric lupus of mice through modulation of CaMKII/NMDAR.展开更多
Background:Diabetic cardiomyopathy(DCM)is a common heart problem in people with diabetes.It is a big public health problem that needs to be treated effectively.Shengmai San(SMS)can be used to treat diabetic cardiomyop...Background:Diabetic cardiomyopathy(DCM)is a common heart problem in people with diabetes.It is a big public health problem that needs to be treated effectively.Shengmai San(SMS)can be used to treat diabetic cardiomyopathy,coronary heart disease,and heart damage,but it is unclear whether it can protect the calcium balance of diabetic cardiomyopathy in the early stages.Objective:To investigate the regulatory mechanism of SMS on sarcoplasmic reticulum calcium transport in diabetic mice.Methods:Eight-week-old db/db mouse models were randomly divided into a diabetic model group(model),SMS intervention group(SMS),and CaMKⅡ inhibitor group(KN-93).Age-matched db/m mice were used as a control group.After 8 weeks of treatment,cardiac function and morphology were assessed,and calcium transients in cardiomyocytes and sarcoplasmic reticulum calcium transport were detected.Western blot was used to detect the expression of CaMKⅡ and proteins related to myocardial calcium transport.Results:In 16-week-old db/db mice,there was no obvious abnormality in myocardial contractile function,the ventricular wall was not thickened,and the cross-sectional area of cardiomyocytes was not significantly enlarged.Compared with the model group,in the SMS group,the calcium transient amplitude was increased,the calcium content of the sarcoplasmic reticulum was upregulated,the calcium elimination time constant was decreased,calcium elimination was accelerated,and the proportion of calcium released from the sarcoplasmic reticulum during the calcium transient was increased.At the same time,SMS could reduce cytosolic free calcium in diabetic mice,and its possible mechanism was to reduce calcium leakage from the sarcoplasmic reticulum,and its effect was similar to that of the KN93 group.The expressions of CaMKⅡ protein and p-CaMKⅡ protein were significantly upregulated in the model group,while SMS could significantly downregulate the expressions of both.Conclusions:SMS can reduce sarcoplasmic reticulum calcium leak and protect the calcium homeostasis of diabetic myocardium.Its mechanism may be by reducing the expression of CaMKⅡ protein and the phosphorylation level of CaMKⅡ protein.展开更多
基金Supported by the National Natural Science Foundation of China,No.81302131
文摘AIM To investigate the role of calmodulin-dependent protein kinase Ⅱ(Ca MKⅡ) in colon cancer growth,migration and invasion.METHODS Ca MKⅡ expression in colon cancer and paracancerous tissues was evaluated via immunochemistry. Transcriptional and posttranscriptional levels of Ca MKⅡin tissue samples and MMP2,MMP9 and TIMP-1 expression in the human colon cancer cell line HCT116 were assessed by q RTPCR and western blot. Cell proliferation was detected with the MTT assay. Cancer cell migration and invasion were investigated with the Transwell culture system and woundhealing assay.RESULTS We first demonstrated that CaMK Ⅱ was ove rexpressed in human colon cancers and was associated with cancer differentiation. In the human colon cancer cell line HCT116,the Ca MKII-specific inhibitor KN93,but not its inactive analogue KN92,decreased cancer cell proliferation. Furthermore,KN93 also significantly prohibited HCT116 cell migration and invasion. The specific inhibition of ERK1/2 or p38 decreased the proliferation and migration of colon cancer cells.CONCLUSION Our findings highlight Ca MKⅡ as a potential critical mediator in human colon tumor development and metastasis.
基金supported by Liaoning Social Development Key Projects of Scientific and Technological Department of Liaoning Province, No. 2012225019
文摘In this study, primary cultured cerebral cortical neurons of Sprague-Dawley neonatal rats were treated with 0.25, 0.5, and 1.0 μM calmodulin-dependent protein kinase II inhibitor KN-93 after 50 μM N-methyI-D-aspartic acid-induced injury. Results showed that, compared with N-methyi-D- aspartic acid-induced injury neurons, the activity of cells markedly increased, apoptosis was significantly reduced, leakage of lactate dehydrogenase decreased, and intracellular Ca2＋ concentrations in neurons reduced after KN-93 treatment. The expression of caspase-3, phosphorylated calmodulin-dependent protein kinase II and total calmodulin-dependent protein kinase II protein decreased after KN-93 treatment. And the effect was apparent at a dose of 1.0 pM KN-93. Experimental findings suggest that KN-93 can induce a dose-dependent neuroprotective effect, and that the underlying mechanism may be related to the down-regulation of caspase-3 and calmodulin- dependent protein kinase II expression.
基金supported by the National Natural Science Foundation of China,No.81101159the Natural Science Foundation of Jiangsu Province of China,No.BK20151268
文摘Septic encephalopathy is a frequent complication of sepsis,but there are few studies examining the role of micro RNAs（mi Rs） in its pathogenesis.In this study,a mi R-219 mimic was transfected into rat hippocampal neurons to model mi R-219 overexpression.A protective effect of mi R-219 was observed for glutamate-induced neurotoxicity of rat hippocampal neurons,and an underlying mechanism involving calmodulin-dependent protein kinase II γ（Ca MKIIγ） was demonstrated.mi R-219 and Ca MKIIγ m RNA expression induced by glutamate in hippocampal neurons was determined by quantitative real-time reverse transcription-polymerase chain reaction（q RT-PCR）.After neurons were transfected with mi R-219 mimic,effects on cell viability and apoptosis were measured by 3-（4,5-dimethylthiazolyl-2）-2,5-diphenyltetrazolium bromide（MTT） assay and flow cytometry.In addition,a luciferase reporter gene system was used to confirm Ca MKIIγ as a target gene of mi R-219.Western blot assay and rescue experiments were also utilized to detect Ca MKIIγ expression and further verify that mi R-219 in hippocampal neurons exerted its effect through regulation of Ca MKIIγ.MTT assay and q RT-PCR results revealed obvious decreases in cell viability and mi R-219 expression after glutamate stimulation,while Ca MKIIγ m RNA expression was increased.MTT,flow cytometry,and caspase-3 activity assays showed that mi R-219 overexpression could elevate glutamate-induced cell viability,and reduce cell apoptosis and caspase-3 activity.Moreover,luciferase Ca MKIIγ-reporter activity was remarkably decreased by co-transfection with mi R-219 mimic,and the results of a rescue experiment showed that Ca MKIIγ overexpression could reverse the biological effects of mi R-219.Collectively,these findings verify that mi R-219 expression was decreased in glutamate-induced neurons,Ca MKIIγ was a target gene of mi R-219,and mi R-219 alleviated glutamate-induced neuronal excitotoxicity by negatively controlling Ca MKIIγ expression.
基金supported by grants from the Fujian Provincial Natural Science Foundation of China (No. 2008J0075)the Fujian Provincial Science and Technology Project of China(No. 2010Y0011)
文摘Cardiac hypertrophy is an independent risk factor for sudden cardiac death in clinical settings and the incidence of sudden cardiac death and ventricular arrhythmias are closely related.The aim of this study was to determine the effects of the calmodulin-dependent protein kinase(CaMK) Ⅱ inhibitor,KN-93,on L-type calcium current(I Ca,L) and early after-depolarizations(EADs) in hypertrophic cardiomyocytes.A rabbit model of myocardial hypertrophy was constructed through abdominal aortic coarctation(LVH group).The control group(sham group) received a sham operation,in which the abdominal aortic was dissected but not coarcted.Eight weeks later,the degree of left ventricular hypertrophy(LVH) was evaluated using echocardiography.Individual cardiomyocyte was isolated through collagenase digestion.Action potentials(APs) and I Ca,L were recorded using the perforated patch clamp technique.APs were recorded under current clamp conditions and I Ca,L was recorded under voltage clamp conditions.The incidence of EADs and I ca,L in the hypertrophic cardiomyocytes were observed under the conditions of low potassium(2 mmol/L),low magnesium(0.25 mmol/L) Tyrode’s solution perfusion,and slow frequency(0.25-0.5 Hz) electrical stimulation.The incidence of EADs and I ca,L in the hypertrophic cardiomyocytes were also evaluated after treatment with different concentrations of KN-92(KN-92 group) and KN-93(KN-93 group).Eight weeks later,the model was successfully established.Under the conditions of low potassium,low magnesium Tyrode’s solution perfusion,and slow frequency electrical stimulation,the incidence of EADs was 0/12,11/12,10/12,and 5/12 in sham group,LVH group,KN-92 group(0.5 μmol/L),and KN-93 group(0.5 μmol/L),respectively.When the drug concentration was increased to 1 μmol/L in KN-92 group and KN-93 group,the incidence of EADs was 10/12 and 2/12,respectively.At 0 mV,the current density was 6.7±1.0 and 6.3±0.7 PA·PF-1 in LVH group and sham group,respectively(P>0.05,n=12).When the drug concentration was 0.5 μmol/L in KN-92 and KN-93 groups,the peak I Ca,L at 0 mV was decreased by(9.4±2.8)% and(10.5±3.0)% in the hypertrophic cardiomyocytes of the two groups,respectively(P>0.05,n=12).When the drug concentration was increased to 1 μmol/L,the peak I Ca,L values were lowered by(13.4±3.7)% and(40±4.9)%,respectively(P<0.01,n=12).KN-93,a specific inhibitor of CaMKII,can effectively inhibit the occurrence of EADs in hypertrophic cardiomyocytes partially by suppressing I Ca,L,which may be the main action mechanism of KN-93 antagonizing the occurrence of ventricular arrhythmias in hypertrophic myocardium.
文摘Metabolic syndrome is a pre-diabetic state characterized by several biochemical and physiological alterations,including insulin resistance,visceral fat accumulation,and dyslipidemias,which increase the risk for developing cardiovascular disease.Metabolic syndrome is associated with augmented sympathetic tone,which could account for the etiology of pre-diabetic cardiomyopathy.This review summarizes the current knowledge of the pathophysiological consequences of enhanced and sustainedβ-adrenergic response in pre-diabetes,focusing on cardiac dysfunction reported in diet-induced experimental models of pre-diabetic cardiomyopathy.The research reviewed indicates that both protein kinase A and Ca^(2+)/calmodulin-dependent protein kinase Ⅱ play important roles in functional responses mediated byβ1-adrenoceptors;therefore,alterations in the expression or function of these kinases can be deleterious.This review also outlines recent information on the role of protein kinase A and Ca^(2+)/calmodulin-dependent protein kinase Ⅱ in abnormal Ca^(2+)handling by cardiomyocytes from diet-induced models of pre-diabetic cardiomyopathy.
文摘OBJECTIVE To determine the functional role of hydrogen sulfide(H_2S) in protecting against mitochondrial dysfunction in heart failure through the inhibition of Ca^(2+)/calmodulin-dependent protein kinaseⅡ(Ca MKⅡ) using wild type and CSE knockout mouse models.METHODS Continuous subcutaneous injection isoprenaline(7.5 mg·kg^(-1) per day),once a day for 4 weeks to induce heart failure in male C57BL/6(6-8 weeks old) mice and CSE-/-mice.150 μmol·L^(-1) H_2O_2 was used to induce oxidative stress in H9c2 cells.Echocardiograph was used to detect cardiac parameters.H&E stain and Masson stain was to observation histopathological changes.Western blot was used to detect protein expression and activity.The si RNA was used to silence protein expression.HPLC was used to detect H_2S level.Biotin assay was used to detect the level of S-sulfhydration protein.RESULTS Treatment with S-propyl-L-cysteine(SPRC) or sodium hydrosulfide(Na HS),modulators of blood H_2S levels,attenuated the development of heart failure in animals,reduced lipid peroxidation,and preserved mitochondrial function.The inhibition Ca MKⅡ phosphorylation by SPRC and Na HS as demonstrated using both in vivo and in vitro models corresponded with the cardioprotective effects of these compounds.Interestingly,Ca MKⅡ activity was found to be elevated in CSE-/-mice as compared to wild type animals and the phosphorylation status of Ca MK Ⅱ appeared to relate to the severity of heart failure.Importantly,in wild type mice SPRC was found to promote S-sulfhydration of Ca MKⅡ leading to reduced activity of this protein however,in CSE-/-mice S-sulfhydration was abolished following SPRC treatment.CONCLUSION A novel mechanism depicting a role of S-sulfhydration in the regulation of Ca MKⅡ is presented.SPRC mediated S-sulfhydration of Ca MKⅡ was found to inhibit Ca MKⅡ activity and to preserve cardiovascular homeostasis.
文摘Using nystatin-perforated whole-cell recording configuration, the modulatory effect of N-methyl-D-aspartate (NMDA) on γ-aminobutyric acid (GABA)-activated whole-cell currents was investigated in neurons freshly dissociated from the rat sacral dorsal commissural nucleus (SDCN). The results showed that: (i) NMDA suppressed GABA- and muscimol (Mus)-activated currents (IGABA and IMUS), respectively in the Mg2+-free external solution containing 1 μmol/L glycine at a holding potential (VH) of -40 mV in SDCN neurons. The selective NMDA receptor antagonist, D-2-amino-5-phosphonovaleric acid (APV, 100 μmol/L), inhibited the NMDA-evoked currents and blocked the NMDA-induced suppression of IGABA; (ii) when the neurons were incubated in a Ca2+-free bath or pre-loaded with a membrane-permeable Ca2+ chelator, BAPTA AM (10 nmol/L), the inhibitory effect of NMDA on IGABA disappeared. Cd2+ (10 μmol/L) or La3+(30 μmol/L), the non-selective blockers of voltage-dependent calcium channels, did not affect the suppression of IGABA by NMDA application; (iii) the suppression of IGABA by NMDA was inhibited by KN-62, a cal-cium/calmodulin-dependent protein kinase II (CaMKII) inhibitor. These results indicated that the inhibition of GABA response by NMDA is Ca2+-dependent and CaMKII is involved in the process of the Ca2+-dependent inhibition.
基金supported by the National Natural Science Funds(81073134)085 First-Class Discipline Construction Innovation Science and Technology Support Project of Shanghai University of TCM(085ZY1206)E-institutes of Shanghai Municipal Education Commission(No E 03008)。
文摘Objective:The aim of this study was to investigate the protective effects of ginsenoside Rb1 and assess whether these protective effects are related to calcium/calmodulin-dependent protein kinaseⅡ(Ca MKⅡ).Methods:A myocardial ischemia(IS)rat.model and a myocardial H9 C2 cell hypoxia model were established.MI was induced by occluding the left anterior descending artery for 120 min.Ginsenoside Rb1(10 mg/kg)was administered 30 min before ischemia induction,and the treatment continued for 7 days.Results:In the rat IS injury model,ginsenoside Rb1 reduced myocardial infarct size,mean left ventricular diastolic pressure,incidence of arrhythmia,and levels of serum creatine kinase,lactate dehydrogenase,and malondialdehyde.However,the mean left ventricular systolic pressure,and maximal rising and falling rates of ventricular pressure(±dp/dtmax)increased.In the myocardial H9 C2 cell hypoxia model,ginsenoside Rb1 reduced intracellular calcium concentrations([Ca2+]i)during hypoxia,and markedly reversed the hypoxia-induced decrease in cell survival.Ginsenoside Rb1 was involved in the downregulation of CaMKⅡand the ryanodine receptor,as well as hypoxia-induced H9 C2 cell survival.Conclusion:The findings of the present study suggest that ginsenoside Rb1 attenuates MI injury in rats,partially through the downregulation of CaMKⅡexpression.
基金the National Basic Research Program (Grant No. G1999 0116), theNational Science Fund for Outstanding Youth (Grant No. 39725015), the National Natural Science Foundation of China (Grant No. 39780015), the National Fund for Transgenic Project (Grant No.
文摘A calmodulin-dependent protein kinase (MCK1) appeared important in regulating flowering in tobacco. The expression of modified MCK1 that lacks the C-terminal including calmodulin-binding domain upsets the flowering developmental program, leading to the abortion of flower primordia initiated on the main axis of the plant and, as well, caused the prolongation of the vegetative phase in axillary buds. The abortion process of flowers began first in the developing anthers and subsequently the entire flower senesces. In axillary buds the prolonged vegetative phase was characterized by atypical elongated, narrow, twisted leaves. These results suggested a role for calmodulin-dependent protein kinase homologs in mediating flowering.
基金Supported by the National High-Tech Research and Development (863) Program of China (No. 2003AA603430) and the National Natural Science Foundation of China (No. 30371092)
文摘Many of the effects of Ca^2＋ signaling are mediated through the Ca^2＋/calmodulin complex and its acceptors, the Ca^2＋/calmodulin-dependent protein kinases, including PSKHI. Studies of the proteins involved in the calcium metabolism in oysters will help elucidate the pearl formation mechanism. This paper describes a full-length PSKH1 cDNA isolated from pearl oyster Pinctada fucata. Oyster PSKH1 shares 65% homology with human PSKH1 and 48% similarity with rat CaM kinase I in the amino acid sequence, and contains a calmodulin-binding domain. The results of semi-quantitative reverse transcription-polymerase chain reaction and in situ hybridization revealed that oyster PSKH1 mRNA is highly expressed in the outer epithelial cells of the mantle pallial and in the gill epithelial cells. These studies provide important information describing the complex Ca^2＋ signaling mechanism in oyster calcium metabolism.
基金supported by the Natural Science Foundation of Hebei Province(H2021206037)the Government-funded Project on Training of Outstanding Clinical Medical Personnel of Hebei Province in the year 2021(303-16-20-06)the Medical Research Project of Hebei Provincial Health Commission(20230031).
文摘Background:Glioma is the most common tumor of the central nervous system with a poor prognosis.This study aims to explore the role of calcium/calmodulin-dependent protein kinase IIβ(CAMK2B)in regulating the malignant progression of glioma cells,as well as the molecular mechanisms underlying these malignant behaviors.Methods:The correlation between CAMK2B expression in gliomas and patient prognosis was analyzed using immunohistochemistry,quantitative reverse transcription polymerase chain reaction(qRT-PCR),and western blot.Furthermore,the study explored the role of CAMK2B in glioma cell proliferation,invasion,and migration using cell counting kit-8(CCK-8),5-Ethynyl-2′-deoxyuridine(EdU),wound healing,transwell,and in vivo tumor xenograft assays.Result:Patients with high CAMK2B expression exhibited significantly better prognostic outcomes compared to those with low expression levels.Furthermore,CAMK2B expression was significantly lower in glioma tissues and cells compared to both normal brain tissue and human astrocyte cell lines.Notably,overexpression of CAMK2B in glioma cells led to an approximate 40%reduction in proliferative capacity and a 60–70%decrease in invasive and migratory abilities,compared to control glioma cells.These differences were statistically significant at p<0.05.Conversely,knockdown of CAMK2B using siRNA-CAMK2B significantly enhanced the proliferative,invasive,and migratory capabilities of glioma cells in both in vitro and in vivo settings,enhancing these abilities by 1.5 to 3 times.Notably,these effects were reversed through the application of the Rat Sarcoma viral oncogene homolog(Ras)pathway inhibitor,Salirasib.Western blot analysis revealed that knockdown of CAMK2B led to activation of the Ras/Rapidly Accelerated Fibrosarcoma(Raf)/Mitogen-activated protein kinase kinase(MEK)/Extracellular signal-regulated kinase(ERK)signaling pathway in glioma cell lines,whereas overexpression of CAMK2B resulted in the suppression of this pathway.Conclusion:CAMK2B inhibits glioma proliferation,invasion,andmigration through the Ras/Raf/MEK/ERK signaling pathway.
基金supported by thegrants from the Saint Luke’s Hospital Foundation(Kansas City,MO,USA)the National Institute of Health(Bethesda,MD,USA)(No.R01-DA010355-16,R01-MH061469-10)
文摘Protein-protein interactions represent an important mechanism for posttranslational modifications of protein expression and function.In brain cells,surface-expressed and membrane-bound neurotransmitter receptors are common proteins that undergo dynamic protein-protein interactions between their intracellular domains and submembranous regulatory proteins.Recently,the Gφi/o -coupled muscarinic M4 receptor（M4R）has been revealed to be one of these receptors.Through direct interaction with the intracellular loops or C-terminal tails of M4Rs,M4R interacting proteins（M4RIPs）vigorously regulate the efficacy of M4R signaling.A synapse-enriched protein kinase,Ca2＋/calmodulin-dependent protein kinase II （CaMKII）,exemplifies a prototype model of M4RIPs,and is capable of binding to the second intracellular loop of M4Rs. Through an activity-and phosphorylation-dependent mechanism,CaMKII potentiates the M4R/Gφi/o-mediated inhibition of M4R efficacy in inhibiting adenylyl cyclase and cAMP production.In striatal neurons where M4Rs are most abundantly expressed,M4RIPs dynamically control M4R activity to maintain a proper cholinergic tone in these neurons.This is critical for maintaining the acetylcholine-dopamine balance in the basal ganglia,which determines the behavioral responsiveness to dopamine stimulation by psychostimulants.
基金supported by the National Natural Science Foundation of China,No.30472241,90709031 and 30973796the Ministry of Science and Technology of China("973"Project),No.2007CB512505+1 种基金provided by the Foundation of Hainan Province,No.310054the Health Department of Hainan Province,Qiong-Wei-45
文摘In the present study, we examined the analgesic effect of repeated electroacupuncture at bilateral Zusanfi （ST36） and Yanglingquan （GB34） once a day for 14 consecutive days in a rat model of chronic sciatic nerve constriction injury-induced neuropathic pain. In addition, concomitant changes in calcium/calmodulin-dependent protein kinase II expression and synaptic ultrastructure of neurons in the hippocampal CA3 region were examined. The thermal pain threshold （paw withdrawal latency） was increased significantly in both groups at 2 weeks after electroacupuncture intervention compared with 2 days of electroacupuncture. In ovariectomized rats with chronic constriction injury, the analgesic effect was significantly reduced. Electroacupuncture for 2 weeks significantly diminished the injury-induced increase in synaptJc cleft width and thinning of the postsynaptJc density, and it significantly suppressed the down-regulation of intracellular calcium/ calmodulin-dependent protein kinase II expression in the hippocampal CA3 region. Repeated electroacupuncture intervention had a cumulative analgesic effect on injury-induced neuropathic pain reactions, and it led to synaptic remodeling of hippocampal neurons and upregulated calcium/calmodulin-dependent protein kJnase II expression in the hippocampal CA3 region.
基金supported by the National Natural Science Foundation of China,No.81730033(to XPG),81701371(to TJX),81801380(to XZ)Natural Science Foundation of Jiangsu Province of China,No.BK20170654(to TJX),BK20170129(to XZ)
文摘Accumulating evidence indicates that inhalation anesthetics induce or increase the risk of cognitive impairment. GLYX-13（rapastinel） acts on the glycine site of N-methyl-D-aspartate receptors（NMDARs） and has been shown to enhance hippocampus-dependent learning and memory function. However, the mechanisms by which GLYX-13 affects learning and memory function are still unclear. In this study, we investigated these mechanisms in a mouse model of long-term anesthesia exposure. Mice were intravenously administered 1 mg/kg GLYX-13 at 2 hours before isoflurane exposure（1.5% for 6 hours）. Cognitive function was assessed using the contextual fear conditioning test and the novel object recognition test. The mRNA expression and phosphorylated protein levels of NMDAR pathway components, N-methyl-D-aspartate receptor subunit 2B（NR2B）-Ca2+/calmodulin dependent protein kinase II（CaMKII）-cyclic adenosine monophosphate response element binding protein（CREB）, in the hippocampus were evaluated by quantitative RT-PCR and western blot assay. Pretreatment with GLYX-13 ameliorated isoflurane exposure-induced cognitive impairment and restored NR2B, CaMKII and CREB mRNA and phosphorylated protein levels. Intracerebroventricular injection of KN93, a selective CaMKII inhibitor, significantly diminished the effect of GLYX-13 on cognitive function and NR2B, CaMKII and CREB levels in the hippocampus. Taken together, our findings suggest that GLYX-13 pretreatment alleviates isoflurane-induced cognitive dysfunction by protecting against perturbation of the NR2B/CaMKII/CREB signaling pathway in the hippocampus. Therefore, GLYX-13 may have therapeutic potential for the treatment of anesthesia-induced cognitive dysfunction. This study was approved by the Experimental Animal Ethics Committee of Drum Tower Hospital affiliated to the Medical College of Nanjing University, China（approval No. 20171102） on November 20, 2017.
文摘Objective:Cardiac hypertrophy is an adaptive reaction of the heart against cardiac overloading,but continuous cardiac hypertrophy can lead to cardiac remodeling and heart failure.Cardiac hypertrophy is mostly considered reversible,and recent studies have indicated that decorin not only prevents cardiac fibrosis associated with hypertension,but also achieves therapeutic effects by blocking fibrosis-related signaling pathways.However,the mechanism of action of decorin remains unknown and unconfirmed.Methods:We determined the degree of myocardial hypertrophy by measuring the ratios of the heart weight/body weight and left ventricular weight/body weight,histological analysis and immunohistochemistry.Western blotting was performed to detect the expression levels of CaMKⅡ,p-CaMKⅡ and MEF-2 in the heart.Results:Our results confirmed that decorin can regulate the CaMKⅡ/MEF-2 signaling pathway,with inhibition thereof being similar to that of decorin in reducing cardiac hypertrophy.Conclusion:Taken together,the results of the present study showed that decorin induced cardiac hypertrophy by regulating the CaMKⅡ/MEF-2 signaling pathway in vivo,revealing a new therapeutic approach for the prevention of cardiac hypertrophy.
基金supported in part by National Institutes of Health Grants NS-079331(to MY)and NS-091201(to MY)
文摘Membrane depolarization induces the release of the serine proteinase tissue-type plasminogen activator（t PA） from the presynaptic terminal of cerebral cortical neurons.Once in the synaptic cleft this t PA promotes the exocytosis and subsequent endocytic retrieval of glutamate-containing synaptic vesicles,and regulates the postsynaptic response to the presynaptic release of glutamate.Indeed,t PA has a bidirectional effect on the composition of the postsynaptic density（PSD） that does not require plasmin generation or the presynaptic release of glutamate,but varies according to the baseline level of neuronal activity.Hence,in inactive neurons t PA induces phosphorylation and accumulation in the PSD of the Ca^（2＋）/calmodulin-dependent protein kinase IIα（pCa MKIIα）,followed by pCa MKIIα-induced phosphorylation and synaptic recruitment of Glu R1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid（AMPA） receptors.In contrast,in active neurons with increased levels of pCa MKIIα in the PSD t PA induces pCa MKIIα and p Glu R1 dephosphorylation and their subsequent removal from the PSD.These effects require active synaptic N-methyl-D-aspartate（NMDA） receptors and cyclin-dependent kinase 5（Cdk5）-induced phosphorylation of the protein phosphatase 1（PP1） at T320.These data indicate that t PA is a homeostatic regulator of the postsynaptic response of cerebral cortical neurons to the presynaptic release of glutamate via bidirectional regulation of the pCa MKIIα/PP1 switch in the PSD.
基金Supported by Natural Science Foundation of Hubei Province of China(2011CDB012)Project of State Key Laboratory of Animal Nutrition(2004DA125184F1012)
文摘Intramuscular fat （IMF） content in chickens significantly contributes to meat quality. The main objective of this study was to assess the expression of calcineudn （CAN） and Ca^2＋/calmodutin-dependent protein kinase （CAME） in lipogene- sis in chicken muscle. The chickens were slaughtered and sampled at the ages of 4, 8, and 16 weeks, respectively. IMF content and the expression of CaN subunits and CaMK isoforms were measured in thigh muscle tissue. The results showed that the IMF contents were higher in chickens at the age of 16 weeks compared with those in chickens at the ages of 4 and 8 weeks （P〈0.05）. The expression levels of fatty acid synthase （FAS） and fatty acid translocase CD36 （FAT/CD36） mRNA in 16-week-old chickens were all significantly up-regulated compared with those in 4-week-old chickens （P〈0.05）. The mRNA levels of CaNB and CaMK IV in 16-week-old chickens were significantly lower than those in 4-week-old chickens （P〈0.05）. But the CaMK II mRNA levels in 16-week-old chickens were significantly higher than those in 4-week-old chickens （P〈0.05）. To investigate the roles of CaMK and CaN in adipogenesis, SV cells were incubated in standard adipogenesis medium for 24 h and treated with specific inhibitor of CaMK and CaN. The ex- pressions of CCAAT/enhancer binding protein β（C/EBPJ3）, sterol regulatory element- binding protein 1 （SREBP1） and peroxisome proliferation-activated receptor ）, （PPARy） were dramatically enhanced by CsA and CaN inhibitor （P〈0.05）. KN93, a CaMK Ⅱ inhibitor, dramatically repressed the expression of those lipogenic genes （P〈0.05）. All the results above indicated that CaN and CaMK had different effects on adipogenesis in the muscle of chickens.
基金supported by Zhejiang Provincial Natural Science Foundation of China under Grant No.ZCLMS25H2705the National Natural Science Foundation of China(No.81973778)+1 种基金2024 Zhejiang Province College Students Science and Technology Innovation Activity Plan(No.2024R410C067)the China Postdoctoral Science Founda-tion(2024M762959).
文摘Background:As many as 80%of patients with neuropsychiatric lupus develop cognitive dysfunction,yet its diagnosis and treatment are underdeveloped.Objective:This study aimed to investigate the therapeutic effects and underlying mechanisms of Liuwei Dihuang Pill on cognitive dysfunction in mice with neuropsychiatric lupus,utilizing research involving the hippocampal neuronal cell line HT22.Methods:A combination of animal and cellular experiments was employed to investigate the preventive treatment of systemic lupus erythematosus associated with cognitive dysfunction using Liuwei dihuang pill.BALB/c mice were induced with imiquimod and pristane,followed by oral administration of Liuwei Dihuang Pill.Behavioral alterations,levels of anti-dsDNA and anti-ribosomal P protein antibodies,hippocampal indices,changes in hip-pocampal tissue and neurons,and levels of NMDARs and CaMKII in the hippocampus were assessed.Lipopolysac-charide was utilized to induce damage in HT22 cells.The efficacy of serum containing Liuwei Dihuang Pill on these cells was evaluated by observing morphological changes,assessing cell viability,and analyzing protein and mRNA content.Results:Treatment with Liuwei dihuang pill significantly improved levels of autoantibodies,urinary protein,behavioral symptoms,nuclear pyknosis,and apoptosis of hippocampal neurons in mice with neuropsychiatric lupus.Furthermore,there was a notable upregulation in the expression levels of NMDARs and CaMKII.Pretreat-ment with serum containing Liuwei Dihuang Pill markedly increased the survival rate of HT22 cells and elevated both protein and mRNA levels of NMDARs and CaMKII compared to the lipopolysaccharide stimulation group.Conclusion:Liuwei dihuang pill has the potential to improve cognitive function of Pritam and imiquimod induce dysfunction in neuropsychiatric lupus of mice through modulation of CaMKII/NMDAR.
基金supported by the Fundamental Research Funds for the Central Public Welfare Research Institutes(JBGS2021006)the National Natural Science Foundation of China(82004244)the Scientific and Technological Innovation Project of the Chinese Academy of Chinese Medical Sciences(NLTS2025009).
文摘Background:Diabetic cardiomyopathy(DCM)is a common heart problem in people with diabetes.It is a big public health problem that needs to be treated effectively.Shengmai San(SMS)can be used to treat diabetic cardiomyopathy,coronary heart disease,and heart damage,but it is unclear whether it can protect the calcium balance of diabetic cardiomyopathy in the early stages.Objective:To investigate the regulatory mechanism of SMS on sarcoplasmic reticulum calcium transport in diabetic mice.Methods:Eight-week-old db/db mouse models were randomly divided into a diabetic model group(model),SMS intervention group(SMS),and CaMKⅡ inhibitor group(KN-93).Age-matched db/m mice were used as a control group.After 8 weeks of treatment,cardiac function and morphology were assessed,and calcium transients in cardiomyocytes and sarcoplasmic reticulum calcium transport were detected.Western blot was used to detect the expression of CaMKⅡ and proteins related to myocardial calcium transport.Results:In 16-week-old db/db mice,there was no obvious abnormality in myocardial contractile function,the ventricular wall was not thickened,and the cross-sectional area of cardiomyocytes was not significantly enlarged.Compared with the model group,in the SMS group,the calcium transient amplitude was increased,the calcium content of the sarcoplasmic reticulum was upregulated,the calcium elimination time constant was decreased,calcium elimination was accelerated,and the proportion of calcium released from the sarcoplasmic reticulum during the calcium transient was increased.At the same time,SMS could reduce cytosolic free calcium in diabetic mice,and its possible mechanism was to reduce calcium leakage from the sarcoplasmic reticulum,and its effect was similar to that of the KN93 group.The expressions of CaMKⅡ protein and p-CaMKⅡ protein were significantly upregulated in the model group,while SMS could significantly downregulate the expressions of both.Conclusions:SMS can reduce sarcoplasmic reticulum calcium leak and protect the calcium homeostasis of diabetic myocardium.Its mechanism may be by reducing the expression of CaMKⅡ protein and the phosphorylation level of CaMKⅡ protein.
