Chronic pain is a leading cause of disability and affects over 30%of military veterans and active duty personnel[1].Pharmacological approaches to long-term chronic pain management increase the risk of negative effects...Chronic pain is a leading cause of disability and affects over 30%of military veterans and active duty personnel[1].Pharmacological approaches to long-term chronic pain management increase the risk of negative effects such as addiction,cardiovascular complications,and immunosuppression[2].In contrast,non-drug treatments like audio analgesia have demonstrated efficacy in pain relief without these side effects.Given the prevalence of chronic pain in the military population,it is essential to explore new treatments that effectively target its underlying mechanisms.One promising option is the Pannexin 1(Panx1)channel-forming protein.Panx1 is a large-pore ion channel in the plasma membrane of dorsal root ganglion(DRG)neurons that allows for the release of Adenosine triphosphate(ATP).Th is commentary elaborates on the fi ndings of Xing et al.[3],who investigated the role of Panx1 in peripheral pain sensitization following infl ammatory stimuli.We examine the role of Panx1 in chronic pain,critique Xing et al.’s[3]adjuvant selection and power analysis,and discuss the challenges of translating fi ndings from animal models to human conditions.展开更多
Background:The channel-forming protein Pannexin1(Panx1)has been implicated in both human studies and animal models of chronic pain,but the underlying mechanisms remain incompletely understood.Methods:Wild-type(WT,n=24...Background:The channel-forming protein Pannexin1(Panx1)has been implicated in both human studies and animal models of chronic pain,but the underlying mechanisms remain incompletely understood.Methods:Wild-type(WT,n=24),global Panx1 KO(n=24),neuron-specific Panx1 KO(n=20),and glia-specific Panx1 KO(n=20)mice were used in this study at Albert Einstein College of Medicine.The von Frey test was used to quantify pain sensitivity in these mice following complete Freund’s adjuvant(CFA)injection(7,14,and 21 d).The qRT-PCR was employed to measure mRNA levels of Panx1,Panx2,Panx3,Cx43,Calhm1,andβ-catenin.Laser scanning confocal microscopy imaging,Sholl analysis,and electrophysiology were utilized to evaluate the impact of Panx1 on neuronal excitability and morphology in Neuro2a and dorsal root ganglion neurons(DRGNs)in which Panx1 expression or function was manipulated.Ethidium bromide(EtBr)dye uptake assay and calcium imaging were employed to investigate the role of Panx1 in adenosine triphosphate(ATP)sensitivity.β-galactosidase(β-gal)staining was applied to determine the relative cellular expression levels of Panx1 in trigeminal ganglia(TG)and DRG of transgenic mice.Results:Global or neuron-specific Panx1 deletion markedly decreased pain thresholds after CFA stimuli(7,14,and 21 d;P<0.01 vs.WT group),indicating that Panx1 was positively correlated with pain sensitivity.In Neuro2a,global Panx1 deletion dramatically reduced neurite extension and inward currents compared to the WT group(P<0.05),revealing that Panx1 enhanced neurogenesis and excitability.Similarly,global Panx1 deletion significantly suppressed Wnt/β-catenin dependent DRG neurogenesis following 5 d of nerve growth factor(NGF)treatment(P<0.01 vs.WT group).Moreover,Panx1 channels enhanced DRG neuron response to ATP after CFA injection(P<0.01 vs.Panx1 KO group).Furthermore,ATP release increased Ca2+responses in DRGNs and satellite glial cells surrounding them following 7 d of CFA treatment(P<0.01 vs.Panx1 KO group),suggesting that Panx1 in glia also impacts exaggerated neuronal excitability.Interestingly,neuron-specific Panx1 deletion was found to markedly reduce differentiation in cultured DRGNs,as evidenced by stunted neurite outgrowth(P<0.05 vs.Panx1 KO group;P<0.01 vs.WT group or GFAP-Cre group),blunted activation of Wnt/β-catenin signaling(P<0.01 vs.WT,Panx1 KO and GFAP-Cre groups),and diminished cell excitability(P<0.01 vs.GFAP-Cre group)and response to ATP stimulation(P<0.01 vs.WT group).Analysis ofβ-gal staining showed that cellular expression levels of Panx1 in neurons are significantly higher(2.5-fold increase)in the DRG than in the TG.Conclusions:The present study revealed that neuronal Panx1 is a prominent driver of peripheral sensitivity in the setting of inflammatory pain through cell-autonomous effects on neuronal excitability.This hyperexcitability dependence on neuronal Panx1 contrasts with inflammatory orofacial pain,where similar studies revealed a prominent role for glial Panx1.The apparent differences in Panx1 expression in neuronal and non-neuronal TG and DRG cells are likely responsible for the distinct impact of these cell types in the two pain models.展开更多
Background:Extracellular adenosine triphosphate(ATP)is an important signal molecule.In previous studies,intensive research had revealed the crucial roles of family with sequence similarity 3 member A(FAM3A)in controll...Background:Extracellular adenosine triphosphate(ATP)is an important signal molecule.In previous studies,intensive research had revealed the crucial roles of family with sequence similarity 3 member A(FAM3A)in controlling hepatic glucolipid metabolism,isletβcell function,adipocyte differentiation,blood pressure,and other biological and pathophysiological processes.Although mitochondrial protein FAM3A plays crucial roles in the regulation of glucolipid metabolism via stimulating ATP release to activate P2 receptor pathways,its mechanism in promoting ATP release in hepatocytes remains unrevealed.Methods:db/db,high-fat diet(HFD)-fed,and global pannexin 1(PANX1)knockout mice,as well as liver sections of individuals,were used in this study.Adenoviruses and adeno-associated viruses were utilized for in vivo gene overexpression or inhibition.To evaluate the metabolic status in mice,oral glucose tolerance test(OGTT),pyruvate tolerance test(PTT),insulin tolerance test(ITT),and magnetic resonance imaging(MRI)were conducted.Protein-protein interactions were determined by coimmunoprecipitation with mass spectrometry(MS)assays.Results:In livers of individuals and mice with steatosis,the expression of ATP-permeable channel PANX1 was increased(P<0.01).Hepatic PANX1 overexpression ameliorated the dysregulated glucolipid metabolism in obese mice.Mice with hepatic PANX1 knockdown or global PANX1 knockout exhibited disturbed glucolipid metabolism.Restoration of hepatic PANX1 rescued the metabolic disorders of PANX1-deficient mice(P<0.05).Mechanistically,ATP release is mediated by the PANX1-activated protein kinase B-forkhead box protein O1(Akt-FOXO1)pathway to inhibit gluconeogenesis via P2Y receptors in hepatocytes.PANX1-mediated ATP release also activated calmodulin(CaM)(P<0.01),which interacted with c-Jun N-terminal kinase(JNK)to inhibit its activity,thereby deactivating the transcription factor activator protein-1(AP1)and repressing fatty acid synthase(FAS)expression and lipid synthesis(P<0.05).FAM3A stimulated the expression of PANX1 via heat shock factor 1(HSF1)in hepatocytes(P<0.05).Notably,FAM3A overexpression failed to promote ATP release,inhibit the expression of gluconeogenic and lipogenic genes,and suppress gluconeogenesis and lipid deposition in PANX1-deficient hepatocytes and livers.Conclusions:PANX1-mediated release of ATP plays a crucial role in maintaining hepatic glucolipid homeostasis,and it confers FAM3A’s suppressive effects on hepatic gluconeogenesis and lipogenesis.展开更多
Connexins and pannexins are two protein families that play an important role in cellular communication. Pannexin 1 (PANX1), one of the members of pannexin family, is a channel protein. It is glycosylated and forms thr...Connexins and pannexins are two protein families that play an important role in cellular communication. Pannexin 1 (PANX1), one of the members of pannexin family, is a channel protein. It is glycosylated and forms three species, GLY0, GLY1, and GLY2. Here, we describe four independent families in which mutations in PANX1 cause familial or sporadic female infertility via a phenotype that we term “oocyte death.” The mutations, which are associated with oocyte death, alter the PANX1 glycosylation pattern, influence the subcellular localization of PANX1 in cultured cells, and result in aberrant PANX1 channel activity, ATP release in oocytes, and mutant PANX1 GLY1. Overexpression of a patient-derived mutation in mice causes infertility, recapitulating the human oocyte death phenotype. Our findings demonstrate the critical role of PANX1 in human oocyte development, provide a genetic explanation for a subtype of infertility, and suggest a potential target for therapeutic intervention for this disease.展开更多
基金supported by the Office of Naval Research Grant(N00014-22-1-2184).
文摘Chronic pain is a leading cause of disability and affects over 30%of military veterans and active duty personnel[1].Pharmacological approaches to long-term chronic pain management increase the risk of negative effects such as addiction,cardiovascular complications,and immunosuppression[2].In contrast,non-drug treatments like audio analgesia have demonstrated efficacy in pain relief without these side effects.Given the prevalence of chronic pain in the military population,it is essential to explore new treatments that effectively target its underlying mechanisms.One promising option is the Pannexin 1(Panx1)channel-forming protein.Panx1 is a large-pore ion channel in the plasma membrane of dorsal root ganglion(DRG)neurons that allows for the release of Adenosine triphosphate(ATP).Th is commentary elaborates on the fi ndings of Xing et al.[3],who investigated the role of Panx1 in peripheral pain sensitization following infl ammatory stimuli.We examine the role of Panx1 in chronic pain,critique Xing et al.’s[3]adjuvant selection and power analysis,and discuss the challenges of translating fi ndings from animal models to human conditions.
基金This work was NIH(R01NS092466),NSFC(U2004201)Central Plains Thousand People Plan of Henan Province(204200510013)+1 种基金Henan Overseas Expertise Introduction Center for Discipline Innovation(CXJD2021002)Key Special Project of Zhengzhou University Disciplinary Construction(XKZDJC202001)。
文摘Background:The channel-forming protein Pannexin1(Panx1)has been implicated in both human studies and animal models of chronic pain,but the underlying mechanisms remain incompletely understood.Methods:Wild-type(WT,n=24),global Panx1 KO(n=24),neuron-specific Panx1 KO(n=20),and glia-specific Panx1 KO(n=20)mice were used in this study at Albert Einstein College of Medicine.The von Frey test was used to quantify pain sensitivity in these mice following complete Freund’s adjuvant(CFA)injection(7,14,and 21 d).The qRT-PCR was employed to measure mRNA levels of Panx1,Panx2,Panx3,Cx43,Calhm1,andβ-catenin.Laser scanning confocal microscopy imaging,Sholl analysis,and electrophysiology were utilized to evaluate the impact of Panx1 on neuronal excitability and morphology in Neuro2a and dorsal root ganglion neurons(DRGNs)in which Panx1 expression or function was manipulated.Ethidium bromide(EtBr)dye uptake assay and calcium imaging were employed to investigate the role of Panx1 in adenosine triphosphate(ATP)sensitivity.β-galactosidase(β-gal)staining was applied to determine the relative cellular expression levels of Panx1 in trigeminal ganglia(TG)and DRG of transgenic mice.Results:Global or neuron-specific Panx1 deletion markedly decreased pain thresholds after CFA stimuli(7,14,and 21 d;P<0.01 vs.WT group),indicating that Panx1 was positively correlated with pain sensitivity.In Neuro2a,global Panx1 deletion dramatically reduced neurite extension and inward currents compared to the WT group(P<0.05),revealing that Panx1 enhanced neurogenesis and excitability.Similarly,global Panx1 deletion significantly suppressed Wnt/β-catenin dependent DRG neurogenesis following 5 d of nerve growth factor(NGF)treatment(P<0.01 vs.WT group).Moreover,Panx1 channels enhanced DRG neuron response to ATP after CFA injection(P<0.01 vs.Panx1 KO group).Furthermore,ATP release increased Ca2+responses in DRGNs and satellite glial cells surrounding them following 7 d of CFA treatment(P<0.01 vs.Panx1 KO group),suggesting that Panx1 in glia also impacts exaggerated neuronal excitability.Interestingly,neuron-specific Panx1 deletion was found to markedly reduce differentiation in cultured DRGNs,as evidenced by stunted neurite outgrowth(P<0.05 vs.Panx1 KO group;P<0.01 vs.WT group or GFAP-Cre group),blunted activation of Wnt/β-catenin signaling(P<0.01 vs.WT,Panx1 KO and GFAP-Cre groups),and diminished cell excitability(P<0.01 vs.GFAP-Cre group)and response to ATP stimulation(P<0.01 vs.WT group).Analysis ofβ-gal staining showed that cellular expression levels of Panx1 in neurons are significantly higher(2.5-fold increase)in the DRG than in the TG.Conclusions:The present study revealed that neuronal Panx1 is a prominent driver of peripheral sensitivity in the setting of inflammatory pain through cell-autonomous effects on neuronal excitability.This hyperexcitability dependence on neuronal Panx1 contrasts with inflammatory orofacial pain,where similar studies revealed a prominent role for glial Panx1.The apparent differences in Panx1 expression in neuronal and non-neuronal TG and DRG cells are likely responsible for the distinct impact of these cell types in the two pain models.
基金supported by the National Natural Science Foundation of China(82070844,82230024,82025008)the Natural Science Foundation of Beijing(7212123)+1 种基金the Peking University People’s Hospital Research and Development Funds(RZ2023-01)the Peking University Medicine Seed Fund for Interdisciplinary Research(BMU2023YFJHMX002,supported by the Fundamental Research Funds for the Central Universities).
文摘Background:Extracellular adenosine triphosphate(ATP)is an important signal molecule.In previous studies,intensive research had revealed the crucial roles of family with sequence similarity 3 member A(FAM3A)in controlling hepatic glucolipid metabolism,isletβcell function,adipocyte differentiation,blood pressure,and other biological and pathophysiological processes.Although mitochondrial protein FAM3A plays crucial roles in the regulation of glucolipid metabolism via stimulating ATP release to activate P2 receptor pathways,its mechanism in promoting ATP release in hepatocytes remains unrevealed.Methods:db/db,high-fat diet(HFD)-fed,and global pannexin 1(PANX1)knockout mice,as well as liver sections of individuals,were used in this study.Adenoviruses and adeno-associated viruses were utilized for in vivo gene overexpression or inhibition.To evaluate the metabolic status in mice,oral glucose tolerance test(OGTT),pyruvate tolerance test(PTT),insulin tolerance test(ITT),and magnetic resonance imaging(MRI)were conducted.Protein-protein interactions were determined by coimmunoprecipitation with mass spectrometry(MS)assays.Results:In livers of individuals and mice with steatosis,the expression of ATP-permeable channel PANX1 was increased(P<0.01).Hepatic PANX1 overexpression ameliorated the dysregulated glucolipid metabolism in obese mice.Mice with hepatic PANX1 knockdown or global PANX1 knockout exhibited disturbed glucolipid metabolism.Restoration of hepatic PANX1 rescued the metabolic disorders of PANX1-deficient mice(P<0.05).Mechanistically,ATP release is mediated by the PANX1-activated protein kinase B-forkhead box protein O1(Akt-FOXO1)pathway to inhibit gluconeogenesis via P2Y receptors in hepatocytes.PANX1-mediated ATP release also activated calmodulin(CaM)(P<0.01),which interacted with c-Jun N-terminal kinase(JNK)to inhibit its activity,thereby deactivating the transcription factor activator protein-1(AP1)and repressing fatty acid synthase(FAS)expression and lipid synthesis(P<0.05).FAM3A stimulated the expression of PANX1 via heat shock factor 1(HSF1)in hepatocytes(P<0.05).Notably,FAM3A overexpression failed to promote ATP release,inhibit the expression of gluconeogenic and lipogenic genes,and suppress gluconeogenesis and lipid deposition in PANX1-deficient hepatocytes and livers.Conclusions:PANX1-mediated release of ATP plays a crucial role in maintaining hepatic glucolipid homeostasis,and it confers FAM3A’s suppressive effects on hepatic gluconeogenesis and lipogenesis.
文摘Connexins and pannexins are two protein families that play an important role in cellular communication. Pannexin 1 (PANX1), one of the members of pannexin family, is a channel protein. It is glycosylated and forms three species, GLY0, GLY1, and GLY2. Here, we describe four independent families in which mutations in PANX1 cause familial or sporadic female infertility via a phenotype that we term “oocyte death.” The mutations, which are associated with oocyte death, alter the PANX1 glycosylation pattern, influence the subcellular localization of PANX1 in cultured cells, and result in aberrant PANX1 channel activity, ATP release in oocytes, and mutant PANX1 GLY1. Overexpression of a patient-derived mutation in mice causes infertility, recapitulating the human oocyte death phenotype. Our findings demonstrate the critical role of PANX1 in human oocyte development, provide a genetic explanation for a subtype of infertility, and suggest a potential target for therapeutic intervention for this disease.
