BACKGROUND Cancer stem cells(CSCs)are a subpopulation of cancer cells with the potential of self-renewal and differentiation.CSCs play critical roles in tumorigenesis,recurrence,metastasis,radiation tolerance and chem...BACKGROUND Cancer stem cells(CSCs)are a subpopulation of cancer cells with the potential of self-renewal and differentiation.CSCs play critical roles in tumorigenesis,recurrence,metastasis,radiation tolerance and chemoresistance.AIM To assess the expression patterns and clinical potential of doublecortin-like kinase 1(DCLK1)and leucine-rich repeat-containing G-protein-coupled receptor 5(Lgr5),as prognostic CSC markers of colorectal cancer(CRC).METHODS The expression of DCLK1 and Lgr5 in CRC tissue sections from 92 patients was determined by immunohistochemistry.Each case was evaluated using a combined scoring method based on signal intensity staining(scored 0-3)and the proportion of positively stained cancer cells(scored 0-3).The final staining score was calculated as the intensity score multiplied by the proportion score.Low expression of DCLK1 and Lgr5 was defined as a score of 0-3;high expression of DCLK1 and Lgr5 was defined as a score of≥4.Specimens were categorized as either high or low expression,and the correlation between the expression of DCLK1 or Lgr5 and clinicopathological factors was investigated.RESULTS DCLK1 and Lgr5 expression levels were significantly positively correlated.CRC patients with high DCLK1,Lgr5 and DCLK1/Lgr5 expressions had poorer progression-free survival and overall survival.Moreover,high expression of DCLK1 was an independent prognostic factor for recurrence and overall survival in patients with CRC by multivariate analysis(P=0.026 and P=0.049,respectively).CONCLUSION DCLK1 may be a potential CSC marker for the recurrence and survival of CRC patients.展开更多
Background:Triple-negative breast cancer(TNBC)is a heterogeneous,recurring cancer characterized by a high rate of metastasis,poor prognosis,and lack of efficient therapies.KBU2046,a small molecule inhibitor,can inhibi...Background:Triple-negative breast cancer(TNBC)is a heterogeneous,recurring cancer characterized by a high rate of metastasis,poor prognosis,and lack of efficient therapies.KBU2046,a small molecule inhibitor,can inhibit cell motility in malignant tumors,including breast cancer.However,the specific targets and the corresponding mechanism of its function remain unclear.Methods:In this study,we employed(3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H tetrazolium)(MTS)assay and transwell assay to investigate the impact of KBU2046 on the proliferation and migration of TNBC cells in vitro.RNA-Seq was used to explore the targets of KBU2046 that inhibit the motility of TNBC.Finally,confirmed the predicted important signaling pathways through RT-qPCR and western blotting.Results:In this study,we found that KBU2046 functioned as a novel transforming growth factor-β(TGF-β1)inhibitor,effectively suppressing tumor cell motility in vitro.Mechanistically,it directly down-regulated leucine-rich repeat-containing 8 family,member E(LRRC8E),latent TGFβ-binding protein 3(LTBP3),dynein light chain 1(DNAL1),and MAF family of bZIP transcription factors(MAFF)genes,along with reduced protein expression of the integrin family.Additionally,KBU2046 decreased phosphorylation levels of Raf and ERK.This deactivation of the ERK signaling pathway impeded cancer invasion and metastasis.Conclusions:In summary,these findings advocate for the utilization of TGF-β1 as a diagnostic and prognostic biomarker and as a therapeutic target in TNBC.Furthermore,our data underscore the potential of KBU2046 as a novel therapeutic strategy for combating cancer metastasis.展开更多
Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascula...Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascular perforation method and exposed the mice to intermittent hypoxia for 8 hours daily for 2 consecutive days to simulate sleep apnea.We found that sleep apnea aggravated brain edema,increased hippocampal neuron apoptosis,and worsened neurological function in this mouse model of subarachnoid hemorrhage.Then,we established an in vitro HT-22 cell model of hemin-induced subarachnoid hemorrhage/intermittent hypoxia and found that the cells died,and lactate dehydrogenase release increased,after 48 hours.We further investigated the underlying mechanism and found that sleep apnea increased the expression of hippocampal neuroinflammatory factors interleukin-1β,interleukin-18,inte rleukin-6,nuclear factorκB,pyro ptosis-related protein caspase-1,pro-caspase-1,and NLRP3,promoted the prolife ration of astrocytes,and increased the expression of hypoxia-inducible factor 1αand apoptosis-associated speck-like protein containing a CARD,which are the key proteins in the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.We also found that knockdown of hypoxia-inducible factor 1αexpression in vitro greatly reduced the damage to HY22 cells.These findings suggest that sleep apnea aggravates early brain injury after subarachnoid hemorrhage by aggravating neuroinflammation and pyroptosis,at least in part through the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.展开更多
Objective To investigate the effects of insulin-like growth factor-1 (IGF-1) and oxidized low density lipoprotein (oxLDL) on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells (VSMCs). Methods Rabb...Objective To investigate the effects of insulin-like growth factor-1 (IGF-1) and oxidized low density lipoprotein (oxLDL) on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells (VSMCs). Methods Rabbit aortic VSMCs were cultured. VSMCs proliferation ability was determined by measuring cell number and mitochondrial dehydrogenase (MD) activity with MTT assay. Western blot was used to detect the protein expression ofphosphatase PHLPP1. Results IGF-1 (100ug/L) increased cell number and MD activity to 3.02 and 3.59 times of that in control group, oxLDL(501xg/ml) elevated the above two parameters to 2.03 and 2.91 times respectively. Western blot showed that IGF-1 and oxLDL inhibited the expression of PHLPPI to 39.27% and 40.26% of the control group (P〈0.01 ). Conclusion IGF- 1 and oxLDL may enhance the proliferation of VSMCs by decreasing the expression ofphosphatase PHLPP 1.展开更多
Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibi...Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.展开更多
Proline-, glutamic acid-, and leucine-rich protein 1 (PELP1) is a scaffolding protein involved in both genomic and nongenomic estrogen signal transduction pathways. To date, the role of PELP1 protein has yet to be c...Proline-, glutamic acid-, and leucine-rich protein 1 (PELP1) is a scaffolding protein involved in both genomic and nongenomic estrogen signal transduction pathways. To date, the role of PELP1 protein has yet to be characterized in human sperm and has not been associated with sperm parameters. To confirm the presence of PELP1 in human sperm, fresh semen samples were obtained from 178 donors. The study was designed to establish both mRNA and protein presence, and protein cellular localization. Additionally, the number of PELP1-positive spermatozoa was analyzed in men with normal and abnormal semen parameters. Sperm parameters were assessed according to the World Health Organization (WHO) 2010 standards. The presence of PELP1 in spermatozoa was investigated using four precise, independent techniques. The qualitative presence of transcripts and protein was assessed using reverse transcription-polymerase chain reaction (RT-PCR) and western blot protocols, respectively. The cellular localization of PELP1 was investigated by immunocytochemistry. Quantitative analysis of PELP1-positive cells was done by flow cytometry. PELP1 mRNA and protein was confirmed in spermatozoa. Immunocytochemical analysis identified the presence of PELP1 in the midpieces of human sperm irrespective of sperm parameters. Becton Dickinson fluorescence-activated cell sorting (FACSCalibur^Tm) analysis revealed a significantly lower number of PELP1-positive cells in males with normal semen parameters versus abnormal samples (42.78% ± 11.77% vs 61.05% ± 21.70%, respectively; P = 0.014). The assessment of PELP1 may be a time-saving method used to obtain information about sperm quality. The results of our study suggest that PEPL1 may be utilized as an indicator of sperm quality; thereby, PELP1 may be an additional biomarker useful in the evaluation of male infertility.展开更多
Large-conductance Ca^(2+)-activated K+channels(BK channels)constitute an key physiological link between cellular Ca^(2+) signaling and electrical signaling at the plasma membrane.Thus these channels are critical to th...Large-conductance Ca^(2+)-activated K+channels(BK channels)constitute an key physiological link between cellular Ca^(2+) signaling and electrical signaling at the plasma membrane.Thus these channels are critical to the control of action potential firing and neurotrans-mitter release in several types of neurons,as well as the dynamic control of smooth muscle tone in resis-tance arteries,airway,and bladder.Recent advances in our understanding of K^(+) channel structure and function have led to new insight toward the molecular mecha-nisms of opening and closing(gating)of these chan-nels.Here we will focus on mechanisms of BK channel gating by Ca^(2+),transmembrane voltage,and auxiliary subunit proteins.展开更多
As evolutionarily conserved signals,roof plate-specific spondins(R-spondins;RSPOs)are a family with four members(RSPO1e4)exerting distinctly different functions.RSPOs have five receptors and correlate with different s...As evolutionarily conserved signals,roof plate-specific spondins(R-spondins;RSPOs)are a family with four members(RSPO1e4)exerting distinctly different functions.RSPOs have five receptors and correlate with different signaling pathways through these receptors and then perform various functions.Moreover,their best-known molecular function is the capacity to enhance WNT signaling pathways,which play critical roles in several processes.A recent study shows that RSPOs not only potentiate the WNT/beta(b)-catenin signaling pathway but are also involved in the WNT/planar cell polarity signaling pathway.RSPOs influence liver homeostasis and the development of multiple liver diseases.RSPO1 increases cell proliferation,protects hepatocytes from injury,improves liver regenerative potential,and affects liver metabolic zonation.RSPO2 not only regulates proliferation-associated genes and promotes differentiation in the liver but also participates in liver fibrosis through the WNT/b-catenin signaling pathway.RSPO3 is a key determinant of proper liver function,such as promoting hepatocyte regeneration and maintaining liver zonation.RSPO3 is upregulated in liver fibrosis and livers of patients with nonalcoholic steatohepatitis.Besides,RSPO2 and RSPO3 are confirmed as oncogenes and involved in the occurrence of liver cancer.The role of RSPO4 in the liver remains unclear.In this review,the structural and biochemical properties of RSPOs and their receptors and their roles in liver homeostasis and disease are summarized.展开更多
Voltage-gated potassium channels(VGKCs)represent a group of tetrameric signaling proteins with several functions,including modulation of neuronal excitability and neurotransmitter release.Moreover,VGKCs give a key con...Voltage-gated potassium channels(VGKCs)represent a group of tetrameric signaling proteins with several functions,including modulation of neuronal excitability and neurotransmitter release.Moreover,VGKCs give a key contribution to the generation of the action potential.VGKCs are complexed with other neuronal proteins,and it is now widely known that serum autoantibodies directed against VGKCs are actually directed against the potassium channel subunits only in a minority of patients.By contrast,these autoantibodies more commonly target three proteins that are complexed with alpha-dendrotoxin-labeled potassium channels in brain extracts.These three proteins are contactin-associated protein-2(Caspr-2),leucine-rich,glioma inactivated 1(LGI-1)protein and the protein Tag-1/contactin-2.Neoplasms are detected only in a minority of seropositive patients for VGKC complex-IgG and do not significantly associate with Caspr-2 or LGI-1.Among all the cancers described in association with VGKC complex-IgG,lung carcinoma,thymoma,and hematologic malignancies are the most commonly detected.We will review all the major neurological conditions associated with VGKC complex-IgG.These include Isaacs’syndrome,Morvan syndrome,limbic encephalitis,facio-brachial dystonic seizures,chorea and other movement disorders,epilepsy,psychosis,gastrointestinal neuromuscular diseases,a subacute encephalopathy that mimics Creutzfeldt-Jakob prion disease both clinically and radiologically and autoimmune chronic pain.The vast majority of these conditions are reversible by immunotherapy,and it is becoming increasingly recognized that early diagnosis and detection of VGKC complex-IgG is critical in order to rapidly start the treatment.As a result,VGKC complex-IgG are now part of the investigation of patients with unexplained subacute onset of epilepsy,memory or cognitive problems,or peripheral nerve hyperexcitability syndromes.展开更多
基金Supported by Sanming Project of Shenzhen,No.SZSM201612041Shenzhen Science and Technology Innovation Commission Project,No.GJHZ20180420180754917 and No.ZDSYS20190902092855097Postdoctoral Science Foundation of China,No.2018M633095.
文摘BACKGROUND Cancer stem cells(CSCs)are a subpopulation of cancer cells with the potential of self-renewal and differentiation.CSCs play critical roles in tumorigenesis,recurrence,metastasis,radiation tolerance and chemoresistance.AIM To assess the expression patterns and clinical potential of doublecortin-like kinase 1(DCLK1)and leucine-rich repeat-containing G-protein-coupled receptor 5(Lgr5),as prognostic CSC markers of colorectal cancer(CRC).METHODS The expression of DCLK1 and Lgr5 in CRC tissue sections from 92 patients was determined by immunohistochemistry.Each case was evaluated using a combined scoring method based on signal intensity staining(scored 0-3)and the proportion of positively stained cancer cells(scored 0-3).The final staining score was calculated as the intensity score multiplied by the proportion score.Low expression of DCLK1 and Lgr5 was defined as a score of 0-3;high expression of DCLK1 and Lgr5 was defined as a score of≥4.Specimens were categorized as either high or low expression,and the correlation between the expression of DCLK1 or Lgr5 and clinicopathological factors was investigated.RESULTS DCLK1 and Lgr5 expression levels were significantly positively correlated.CRC patients with high DCLK1,Lgr5 and DCLK1/Lgr5 expressions had poorer progression-free survival and overall survival.Moreover,high expression of DCLK1 was an independent prognostic factor for recurrence and overall survival in patients with CRC by multivariate analysis(P=0.026 and P=0.049,respectively).CONCLUSION DCLK1 may be a potential CSC marker for the recurrence and survival of CRC patients.
基金support from various funding sources,including the National Natural Science Foundation of China(Grant Nos.U21A20415,82002531)Hebei Provincial Key Research Projects(Grant No.223777157D)the Beijing Health Promotion Association,China(2022).
文摘Background:Triple-negative breast cancer(TNBC)is a heterogeneous,recurring cancer characterized by a high rate of metastasis,poor prognosis,and lack of efficient therapies.KBU2046,a small molecule inhibitor,can inhibit cell motility in malignant tumors,including breast cancer.However,the specific targets and the corresponding mechanism of its function remain unclear.Methods:In this study,we employed(3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H tetrazolium)(MTS)assay and transwell assay to investigate the impact of KBU2046 on the proliferation and migration of TNBC cells in vitro.RNA-Seq was used to explore the targets of KBU2046 that inhibit the motility of TNBC.Finally,confirmed the predicted important signaling pathways through RT-qPCR and western blotting.Results:In this study,we found that KBU2046 functioned as a novel transforming growth factor-β(TGF-β1)inhibitor,effectively suppressing tumor cell motility in vitro.Mechanistically,it directly down-regulated leucine-rich repeat-containing 8 family,member E(LRRC8E),latent TGFβ-binding protein 3(LTBP3),dynein light chain 1(DNAL1),and MAF family of bZIP transcription factors(MAFF)genes,along with reduced protein expression of the integrin family.Additionally,KBU2046 decreased phosphorylation levels of Raf and ERK.This deactivation of the ERK signaling pathway impeded cancer invasion and metastasis.Conclusions:In summary,these findings advocate for the utilization of TGF-β1 as a diagnostic and prognostic biomarker and as a therapeutic target in TNBC.Furthermore,our data underscore the potential of KBU2046 as a novel therapeutic strategy for combating cancer metastasis.
基金the Natural Science Foundation of Jiangsu Province(Youth Program),No.BK20190129National Scientific Program of Jiangsu Colleges and Universities of China,No.19KJB320012(both to LY)。
文摘Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascular perforation method and exposed the mice to intermittent hypoxia for 8 hours daily for 2 consecutive days to simulate sleep apnea.We found that sleep apnea aggravated brain edema,increased hippocampal neuron apoptosis,and worsened neurological function in this mouse model of subarachnoid hemorrhage.Then,we established an in vitro HT-22 cell model of hemin-induced subarachnoid hemorrhage/intermittent hypoxia and found that the cells died,and lactate dehydrogenase release increased,after 48 hours.We further investigated the underlying mechanism and found that sleep apnea increased the expression of hippocampal neuroinflammatory factors interleukin-1β,interleukin-18,inte rleukin-6,nuclear factorκB,pyro ptosis-related protein caspase-1,pro-caspase-1,and NLRP3,promoted the prolife ration of astrocytes,and increased the expression of hypoxia-inducible factor 1αand apoptosis-associated speck-like protein containing a CARD,which are the key proteins in the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.We also found that knockdown of hypoxia-inducible factor 1αexpression in vitro greatly reduced the damage to HY22 cells.These findings suggest that sleep apnea aggravates early brain injury after subarachnoid hemorrhage by aggravating neuroinflammation and pyroptosis,at least in part through the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.
文摘Objective To investigate the effects of insulin-like growth factor-1 (IGF-1) and oxidized low density lipoprotein (oxLDL) on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells (VSMCs). Methods Rabbit aortic VSMCs were cultured. VSMCs proliferation ability was determined by measuring cell number and mitochondrial dehydrogenase (MD) activity with MTT assay. Western blot was used to detect the protein expression ofphosphatase PHLPP1. Results IGF-1 (100ug/L) increased cell number and MD activity to 3.02 and 3.59 times of that in control group, oxLDL(501xg/ml) elevated the above two parameters to 2.03 and 2.91 times respectively. Western blot showed that IGF-1 and oxLDL inhibited the expression of PHLPPI to 39.27% and 40.26% of the control group (P〈0.01 ). Conclusion IGF- 1 and oxLDL may enhance the proliferation of VSMCs by decreasing the expression ofphosphatase PHLPP 1.
基金a Ph D fellowship by FCT-Fundacao para a Ciência Tecnologia (SFRH/BD/135868/2018)(to SSC)。
文摘Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.
文摘Proline-, glutamic acid-, and leucine-rich protein 1 (PELP1) is a scaffolding protein involved in both genomic and nongenomic estrogen signal transduction pathways. To date, the role of PELP1 protein has yet to be characterized in human sperm and has not been associated with sperm parameters. To confirm the presence of PELP1 in human sperm, fresh semen samples were obtained from 178 donors. The study was designed to establish both mRNA and protein presence, and protein cellular localization. Additionally, the number of PELP1-positive spermatozoa was analyzed in men with normal and abnormal semen parameters. Sperm parameters were assessed according to the World Health Organization (WHO) 2010 standards. The presence of PELP1 in spermatozoa was investigated using four precise, independent techniques. The qualitative presence of transcripts and protein was assessed using reverse transcription-polymerase chain reaction (RT-PCR) and western blot protocols, respectively. The cellular localization of PELP1 was investigated by immunocytochemistry. Quantitative analysis of PELP1-positive cells was done by flow cytometry. PELP1 mRNA and protein was confirmed in spermatozoa. Immunocytochemical analysis identified the presence of PELP1 in the midpieces of human sperm irrespective of sperm parameters. Becton Dickinson fluorescence-activated cell sorting (FACSCalibur^Tm) analysis revealed a significantly lower number of PELP1-positive cells in males with normal semen parameters versus abnormal samples (42.78% ± 11.77% vs 61.05% ± 21.70%, respectively; P = 0.014). The assessment of PELP1 may be a time-saving method used to obtain information about sperm quality. The results of our study suggest that PEPL1 may be utilized as an indicator of sperm quality; thereby, PELP1 may be an additional biomarker useful in the evaluation of male infertility.
基金supported in part by the National Institute of General Medical Science of the National Institutes of Health(Grant No.R01GM068523).
文摘Large-conductance Ca^(2+)-activated K+channels(BK channels)constitute an key physiological link between cellular Ca^(2+) signaling and electrical signaling at the plasma membrane.Thus these channels are critical to the control of action potential firing and neurotrans-mitter release in several types of neurons,as well as the dynamic control of smooth muscle tone in resis-tance arteries,airway,and bladder.Recent advances in our understanding of K^(+) channel structure and function have led to new insight toward the molecular mecha-nisms of opening and closing(gating)of these chan-nels.Here we will focus on mechanisms of BK channel gating by Ca^(2+),transmembrane voltage,and auxiliary subunit proteins.
基金This work was supported by grants from the Scientific Research Common Program of Beijing Municipal Commission of Education(No.KM202010025029)the National Natural Science Foundation of China(No.82070623 and 81970532)the Beijing Natural Science Foundation(No.7202007).
文摘As evolutionarily conserved signals,roof plate-specific spondins(R-spondins;RSPOs)are a family with four members(RSPO1e4)exerting distinctly different functions.RSPOs have five receptors and correlate with different signaling pathways through these receptors and then perform various functions.Moreover,their best-known molecular function is the capacity to enhance WNT signaling pathways,which play critical roles in several processes.A recent study shows that RSPOs not only potentiate the WNT/beta(b)-catenin signaling pathway but are also involved in the WNT/planar cell polarity signaling pathway.RSPOs influence liver homeostasis and the development of multiple liver diseases.RSPO1 increases cell proliferation,protects hepatocytes from injury,improves liver regenerative potential,and affects liver metabolic zonation.RSPO2 not only regulates proliferation-associated genes and promotes differentiation in the liver but also participates in liver fibrosis through the WNT/b-catenin signaling pathway.RSPO3 is a key determinant of proper liver function,such as promoting hepatocyte regeneration and maintaining liver zonation.RSPO3 is upregulated in liver fibrosis and livers of patients with nonalcoholic steatohepatitis.Besides,RSPO2 and RSPO3 are confirmed as oncogenes and involved in the occurrence of liver cancer.The role of RSPO4 in the liver remains unclear.In this review,the structural and biochemical properties of RSPOs and their receptors and their roles in liver homeostasis and disease are summarized.
文摘Voltage-gated potassium channels(VGKCs)represent a group of tetrameric signaling proteins with several functions,including modulation of neuronal excitability and neurotransmitter release.Moreover,VGKCs give a key contribution to the generation of the action potential.VGKCs are complexed with other neuronal proteins,and it is now widely known that serum autoantibodies directed against VGKCs are actually directed against the potassium channel subunits only in a minority of patients.By contrast,these autoantibodies more commonly target three proteins that are complexed with alpha-dendrotoxin-labeled potassium channels in brain extracts.These three proteins are contactin-associated protein-2(Caspr-2),leucine-rich,glioma inactivated 1(LGI-1)protein and the protein Tag-1/contactin-2.Neoplasms are detected only in a minority of seropositive patients for VGKC complex-IgG and do not significantly associate with Caspr-2 or LGI-1.Among all the cancers described in association with VGKC complex-IgG,lung carcinoma,thymoma,and hematologic malignancies are the most commonly detected.We will review all the major neurological conditions associated with VGKC complex-IgG.These include Isaacs’syndrome,Morvan syndrome,limbic encephalitis,facio-brachial dystonic seizures,chorea and other movement disorders,epilepsy,psychosis,gastrointestinal neuromuscular diseases,a subacute encephalopathy that mimics Creutzfeldt-Jakob prion disease both clinically and radiologically and autoimmune chronic pain.The vast majority of these conditions are reversible by immunotherapy,and it is becoming increasingly recognized that early diagnosis and detection of VGKC complex-IgG is critical in order to rapidly start the treatment.As a result,VGKC complex-IgG are now part of the investigation of patients with unexplained subacute onset of epilepsy,memory or cognitive problems,or peripheral nerve hyperexcitability syndromes.