Objectives To investigate the effect of Gαq/11 signaling pathway and ATP-sensitive potassium channel ( KATP channel ) on ischemic preconditioning (IPC) protection in rat hearts. Methods Two series of experiments were...Objectives To investigate the effect of Gαq/11 signaling pathway and ATP-sensitive potassium channel ( KATP channel ) on ischemic preconditioning (IPC) protection in rat hearts. Methods Two series of experiments were performed in Wistar rat hearts. In the first series of experiment, ischemic preconditioning was induced by left anterior descending occlusion (three, 5 min episodes separated by 5 min of reperfusion), ischemia-reperfusion injury was induced by 30 min coronary artery occlusion followed by 90 min reperfusion. Hemodynamics, infarct size and scores of ventricular arrhythmias were measured. The expression of Gαq/11 protein in the heart was measured by Western blot analysis in the second series. Results Ischemic preconditioning rats showed decreased infarct size and scores of ventricular arrhythmia vs non-IP control rats. The effect of IPC was significantly attenuated by glibenclamide (1 mg/kg, ip), a nonselective KATP channel inhibitor. IPC caused a significant increase in the expression of Gαq/11 protein. Conclusions Activations of Gαq/11 signal pathway and KATP channel played significant roles in the classical cardioprotection of ischemic precon-ditioning rat heart and might be an important mechanism of signal transduction pathway during the ischemic preconditioning.展开更多
鸟嘌呤核苷酸结合蛋白q多肽(Guanine nucleotide binding protein q polypeptide,GNAQ)是GTP结合蛋白异源三聚体的组成部分,能够通过结合细胞表面受体介导下游信号通路。最近的研究发现,葡萄酒色斑(Port-wine stains,PWS)中GNAQ p.Arg18...鸟嘌呤核苷酸结合蛋白q多肽(Guanine nucleotide binding protein q polypeptide,GNAQ)是GTP结合蛋白异源三聚体的组成部分,能够通过结合细胞表面受体介导下游信号通路。最近的研究发现,葡萄酒色斑(Port-wine stains,PWS)中GNAQ p.Arg183点突变,可能介导细胞外信号调节激酶(Extracellular signal-regulated kinase,ERK)信号通路。本文对GNAQ基因突变可能介导的下游信号通路,包括丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)、G蛋白信号调节因子5(regulator of G protein signaling 5,RGS5)、蛋白激酶C(protein kinase C,PKC)和YAP等信号通路进行综述。展开更多
Constitutive activation of GNAQ/11 is the initiative oncogenic event in uveal melanoma(UM).Direct targeting GNAQ/11 has yet to be proven feasible as they are vital for a plethora of cellular functions.In search of gen...Constitutive activation of GNAQ/11 is the initiative oncogenic event in uveal melanoma(UM).Direct targeting GNAQ/11 has yet to be proven feasible as they are vital for a plethora of cellular functions.In search of genetic vulnerability for UM,we found that inhibition of euchromatic histone lysine methyltransferase 2(EHMT2)expression or activity significantly reduced the proliferation and migration capacity of cancer cells.Notably,elevated expression of EHMT2 had been validated in UM samples.Furthermore,Kaplan-Meier survival analysis indicated high EHMT2 protein level was related to poor recurrence-free survival and a more advanced T stage.Chromatin immunoprecipitation sequencing analysis and the following mechanistic investigation showed that ARHGAP29 was a downstream target of EHMT2.Its transcription was suppressed by EHMT2 in a methyltransferasedependent pattern in GNAQ/11-mutant UM cells,leading to elevated RhoA activity.Rescuing constitutively active RhoA in UM cells lacking EHMT2 restored oncogenic phenotypes.Simultaneously blocking EHMT2 and GNAQ/11 signaling in vitro and in vivo showed a synergistic effect on UM growth,suggesting the driver role of these two key molecules.In summary,our study shows evidence for an epigenetic program of EHMT2 regulation that influences UM progression and indicates inhibiting EHMT2 and MEK/ERK simultaneously as a therapeutic strategy in GNAQ/11-mutant UM.展开更多
Constitutively activated G proteins caused by specific mutations mediate the development of multiple malignancies. The mutated Gaq/11 are perceived as oncogenic drivers in the vast majority of uveal melanoma(UM) cases...Constitutively activated G proteins caused by specific mutations mediate the development of multiple malignancies. The mutated Gaq/11 are perceived as oncogenic drivers in the vast majority of uveal melanoma(UM) cases, making directly targeting Gaq/11 to be a promising strategy for combating UM. Herein, we report the optimization of imidazopiperazine derivatives as Gaq/11 inhibitors, and identified GQ262 with improved Gaq/11 inhibitory activity and drug-like properties. GQ262 efficiently blocked UM cell proliferation and migration in vitro. Analysis of the apoptosis-related proteins, extracellular signal-regulated kinase(ERK), and yes-associated protein(YAP) demonstrated that GQ262 distinctly induced UM cells apoptosis and disrupted the downstream effectors by targeting Gaq/11directly. Significantly, GQ262 showed outstanding antitumor efficacy in vivo with good safety at the testing dose. Collectively, our findings along with the favorable pharmacokinetics of GQ262 revealed that directly targeting Gaq/11 may be an efficient strategy against uveal melanoma.展开更多
Type 2 diabetes mellitus is a metabolic disorder of deranged fat, protein and carbohydrate metabolism resulting in hyperglycemia as a result of insulin resistance and inadequate insulin secretion. Although a wide vari...Type 2 diabetes mellitus is a metabolic disorder of deranged fat, protein and carbohydrate metabolism resulting in hyperglycemia as a result of insulin resistance and inadequate insulin secretion. Although a wide variety of diabetes therapies is available, yet limited efficacy, adverse effects, cost, contraindications, renal dosage adjustments, inflexible dosing schedules and weight gain significantly limit their use. In addition, many patients in the United States fail to meet the therapeutic HbA1c goal of 【 7% set by the American Diabetes Association. As such new and emerging diabetes therapies with different mechanisms of action hope to address some of these drawbacks to improve the patient with type 2 diabetes. This article reviews new and emerging classes, including the sodium-glucosecotransporter-2 inhibitors, 11β-Hydroxysteroid dehydrogenase type 1 inhibitors, glycogen phosphorylase inhibitors; protein tyrosine phosphatase 1B inhibitors, G Protein-Coupled receptor agonists and glucokinase activators. These emerging diabetes agents hold the promise of providing benefit of glucose lowering, weight reduction, low hypoglycemia risk, improve insulin sensitivity, pancreatic β cell preservation, and oral formulation availability. However, further studies are needed to evaluate their safety profile, cardiovascular effects, and efficacy durability in order to determine their role in type 2 diabetes management.展开更多
Colorectal cancer(CRC)is a type of malignant tumor that seriously threatens human health and life,and its treatment has always been a difficulty and hotspot in research.Herein,this study for the first time reports tha...Colorectal cancer(CRC)is a type of malignant tumor that seriously threatens human health and life,and its treatment has always been a difficulty and hotspot in research.Herein,this study for the first time reports that antipsychotic aripiprazole(Ari)against the proliferation of CRC cells both in vitro and in vivo,but with less damage in normal colon cells.Mechanistically,the results showed that5-hydroxytryptamine 2B receptor(HTR2B)and its coupling protein G protein subunit alpha q(Gaq)were highly distributed in CRC cells.Ari had a strong affinity with HTR2B and inhibited HTR2B downstream signaling.Blockade of HTR2B signaling suppressed the growth of CRC cells,but HTR2B was not found to have independent anticancer activity.Interestingly,the binding of Gaq to HTR2B was decreased after Ari treatment.Knockdown of Gaq not only restricted CRC cell growth,but also directly affected the antiCRC efficacy of Ari.Moreover,an interaction between Ari and Gaq was found in that the mutation at amino acid 190 of Gaq reduced the efficacy of Ari.Thus,these results confirm that Gaq coupled to HTR2B was a potential target of Ari in mediating CRC proliferation.Collectively,this study provides a novel effective strategy for CRC therapy and favorable evidence for promoting Ari as an anticancer agent.展开更多
文摘Objectives To investigate the effect of Gαq/11 signaling pathway and ATP-sensitive potassium channel ( KATP channel ) on ischemic preconditioning (IPC) protection in rat hearts. Methods Two series of experiments were performed in Wistar rat hearts. In the first series of experiment, ischemic preconditioning was induced by left anterior descending occlusion (three, 5 min episodes separated by 5 min of reperfusion), ischemia-reperfusion injury was induced by 30 min coronary artery occlusion followed by 90 min reperfusion. Hemodynamics, infarct size and scores of ventricular arrhythmias were measured. The expression of Gαq/11 protein in the heart was measured by Western blot analysis in the second series. Results Ischemic preconditioning rats showed decreased infarct size and scores of ventricular arrhythmia vs non-IP control rats. The effect of IPC was significantly attenuated by glibenclamide (1 mg/kg, ip), a nonselective KATP channel inhibitor. IPC caused a significant increase in the expression of Gαq/11 protein. Conclusions Activations of Gαq/11 signal pathway and KATP channel played significant roles in the classical cardioprotection of ischemic precon-ditioning rat heart and might be an important mechanism of signal transduction pathway during the ischemic preconditioning.
文摘鸟嘌呤核苷酸结合蛋白q多肽(Guanine nucleotide binding protein q polypeptide,GNAQ)是GTP结合蛋白异源三聚体的组成部分,能够通过结合细胞表面受体介导下游信号通路。最近的研究发现,葡萄酒色斑(Port-wine stains,PWS)中GNAQ p.Arg183点突变,可能介导细胞外信号调节激酶(Extracellular signal-regulated kinase,ERK)信号通路。本文对GNAQ基因突变可能介导的下游信号通路,包括丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)、G蛋白信号调节因子5(regulator of G protein signaling 5,RGS5)、蛋白激酶C(protein kinase C,PKC)和YAP等信号通路进行综述。
基金supported by the Science and Technology Commission of Shanghai(20DZ2270800,China)the National Natural Science Foundation of China(grants 82073889)+1 种基金the Innovative Research Team of High-level Local Universities in Shanghai(SHSMU-ZDCX20210900,China)China Postdoctoral Science Foundation(2022M722120,China)and Shanghai Sailing Program(22YF1422800,China)。
文摘Constitutive activation of GNAQ/11 is the initiative oncogenic event in uveal melanoma(UM).Direct targeting GNAQ/11 has yet to be proven feasible as they are vital for a plethora of cellular functions.In search of genetic vulnerability for UM,we found that inhibition of euchromatic histone lysine methyltransferase 2(EHMT2)expression or activity significantly reduced the proliferation and migration capacity of cancer cells.Notably,elevated expression of EHMT2 had been validated in UM samples.Furthermore,Kaplan-Meier survival analysis indicated high EHMT2 protein level was related to poor recurrence-free survival and a more advanced T stage.Chromatin immunoprecipitation sequencing analysis and the following mechanistic investigation showed that ARHGAP29 was a downstream target of EHMT2.Its transcription was suppressed by EHMT2 in a methyltransferasedependent pattern in GNAQ/11-mutant UM cells,leading to elevated RhoA activity.Rescuing constitutively active RhoA in UM cells lacking EHMT2 restored oncogenic phenotypes.Simultaneously blocking EHMT2 and GNAQ/11 signaling in vitro and in vivo showed a synergistic effect on UM growth,suggesting the driver role of these two key molecules.In summary,our study shows evidence for an epigenetic program of EHMT2 regulation that influences UM progression and indicates inhibiting EHMT2 and MEK/ERK simultaneously as a therapeutic strategy in GNAQ/11-mutant UM.
基金financial support by National Natural Science Foundation of China (No.22077144 and 81973359)Guangdong Natural Science Funds for Distinguished Young Scholar (No.2018B030306017,China)+4 种基金Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery (2019B030301005,China)Key Reasearch and Development Program of Guangdong Province (2020B1111110003,China)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01Y093,China)National Engineering and Technology Research Center for New Drug Druggability Evaluation (Seed Program of Guangdong Province,2017B090903004)Jilin Province Science and Technology Development Project (20200404105YY)。
文摘Constitutively activated G proteins caused by specific mutations mediate the development of multiple malignancies. The mutated Gaq/11 are perceived as oncogenic drivers in the vast majority of uveal melanoma(UM) cases, making directly targeting Gaq/11 to be a promising strategy for combating UM. Herein, we report the optimization of imidazopiperazine derivatives as Gaq/11 inhibitors, and identified GQ262 with improved Gaq/11 inhibitory activity and drug-like properties. GQ262 efficiently blocked UM cell proliferation and migration in vitro. Analysis of the apoptosis-related proteins, extracellular signal-regulated kinase(ERK), and yes-associated protein(YAP) demonstrated that GQ262 distinctly induced UM cells apoptosis and disrupted the downstream effectors by targeting Gaq/11directly. Significantly, GQ262 showed outstanding antitumor efficacy in vivo with good safety at the testing dose. Collectively, our findings along with the favorable pharmacokinetics of GQ262 revealed that directly targeting Gaq/11 may be an efficient strategy against uveal melanoma.
文摘Type 2 diabetes mellitus is a metabolic disorder of deranged fat, protein and carbohydrate metabolism resulting in hyperglycemia as a result of insulin resistance and inadequate insulin secretion. Although a wide variety of diabetes therapies is available, yet limited efficacy, adverse effects, cost, contraindications, renal dosage adjustments, inflexible dosing schedules and weight gain significantly limit their use. In addition, many patients in the United States fail to meet the therapeutic HbA1c goal of 【 7% set by the American Diabetes Association. As such new and emerging diabetes therapies with different mechanisms of action hope to address some of these drawbacks to improve the patient with type 2 diabetes. This article reviews new and emerging classes, including the sodium-glucosecotransporter-2 inhibitors, 11β-Hydroxysteroid dehydrogenase type 1 inhibitors, glycogen phosphorylase inhibitors; protein tyrosine phosphatase 1B inhibitors, G Protein-Coupled receptor agonists and glucokinase activators. These emerging diabetes agents hold the promise of providing benefit of glucose lowering, weight reduction, low hypoglycemia risk, improve insulin sensitivity, pancreatic β cell preservation, and oral formulation availability. However, further studies are needed to evaluate their safety profile, cardiovascular effects, and efficacy durability in order to determine their role in type 2 diabetes management.
基金supported by Chongqing basic research and frontier exploration project(cstc2022ycjh-bgzxm0119,China)。
文摘Colorectal cancer(CRC)is a type of malignant tumor that seriously threatens human health and life,and its treatment has always been a difficulty and hotspot in research.Herein,this study for the first time reports that antipsychotic aripiprazole(Ari)against the proliferation of CRC cells both in vitro and in vivo,but with less damage in normal colon cells.Mechanistically,the results showed that5-hydroxytryptamine 2B receptor(HTR2B)and its coupling protein G protein subunit alpha q(Gaq)were highly distributed in CRC cells.Ari had a strong affinity with HTR2B and inhibited HTR2B downstream signaling.Blockade of HTR2B signaling suppressed the growth of CRC cells,but HTR2B was not found to have independent anticancer activity.Interestingly,the binding of Gaq to HTR2B was decreased after Ari treatment.Knockdown of Gaq not only restricted CRC cell growth,but also directly affected the antiCRC efficacy of Ari.Moreover,an interaction between Ari and Gaq was found in that the mutation at amino acid 190 of Gaq reduced the efficacy of Ari.Thus,these results confirm that Gaq coupled to HTR2B was a potential target of Ari in mediating CRC proliferation.Collectively,this study provides a novel effective strategy for CRC therapy and favorable evidence for promoting Ari as an anticancer agent.
