Dorsal root ganglion （DRG） neurons from newborn Wistar rats cultured in vitro were pressurized with 20, 40, 80 or 120 mm Hg compressive Ioadings （1 mm Hg = 0.133 kPa） for 12, 24, 48 or 72 hours, respectively. The ...Dorsal root ganglion （DRG） neurons from newborn Wistar rats cultured in vitro were pressurized with 20, 40, 80 or 120 mm Hg compressive Ioadings （1 mm Hg = 0.133 kPa） for 12, 24, 48 or 72 hours, respectively. The 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide test showed that pressures less than 80 mm Hg had no obvious impact on the activity of DRG neurons. The protein expression levels of transient receptor potential vanilloid receptor 4 （TRPV4）, transient receptor potential vanilloid receptor 1, transient receptor potential channel of melastatin type 8, and transient receptor potential subtype ankyrin 1 were assessed by western blot analysis. The mRNA expression of TRPV4 was assessed by real-time PCR. The results showed that sustained mechanical compression up-regulated TRPV4 mRNA and protein expression in the rat DRG neurons, in a time-dependent fashion. Similar changes were not found in the protein expression of transient receptor potential vanilloid receptor 1, transient receptor potential channel of melastatin type 8, and transient receptor potential subtype ankyrin 1. Images of cells using a laser scanning confocal microscope showed that the sustained mechanical pressure increased the number of responsive DRG neurons and was synergistic on the enhanced Ca^2＋ responses to the TRPV4 phorbol ester agonist 4a-phorbo112, 13-didecanoate and hypotonic solutions. These findings demonstrate that sustained mechanical compressive loading in vitro increases the expression of TRPV4 mRNA and protein in DRG neurons and sensitizes TRPV4 Ca^2＋ signals. Mechanical compression does not impact other ion channels in the transient receptor potential family.展开更多
BACKGROUND Serotonin receptor 2B(5-HT2B receptor)plays a critical role in many chronic pain conditions.The possible involvement of the 5-HT2B receptor in the altered gut sensation of irritable bowel syndrome with diar...BACKGROUND Serotonin receptor 2B(5-HT2B receptor)plays a critical role in many chronic pain conditions.The possible involvement of the 5-HT2B receptor in the altered gut sensation of irritable bowel syndrome with diarrhea(IBS-D)was investigated in the present study.AIM To investigate the possible involvement of 5-HT2B receptor in the altered gut sensation in rat model and patients with IBS-D.METHODS Rectosigmoid biopsies were collected from 18 patients with IBS-D and 10 patients with irritable bowel syndrome with constipation who fulfilled the Rome IV criteria and 15 healthy controls.The expression level of the 5-HT2B receptor in colon tissue was measured using an enzyme-linked immunosorbent assay and correlated with abdominal pain scores.The IBS-D rat model was induced by intracolonic instillation of acetic acid and wrap restraint.Alterations in visceral sensitivity and 5-HT2B receptor and transient receptor potential vanilloid type 1(TRPV1)expression were examined following 5-HT2B receptor antagonist adminis-tration.Changes in visceral sensitivity after administration of the TRPV1 antago-INTRODUCTION Irritable bowel syndrome(IBS)is a chronic functional bowel disorder characterized by recurrent abdominal pain with altered bowel habits that affects approximately 15%of the population worldwide[1].IBS significantly impacts the quality of life of patients.Although the pathogenesis of IBS is not completely understood,the role of abnormal visceral sensitivity in IBS has recently emerged[2,3].5-Hydroxytryptamine(5-HT)is known to play a key role in the physiological states of the gastrointestinal tract.Plasma 5-HT levels in IBS with diarrhea(IBS-D)patients were greater than those in healthy controls[4],suggesting a possible role of 5-HT in the pathogenesis of IBS-D.The serotonin receptor 2(5-HT2 receptor)family comprises three subtypes:5-HT2A,5-HT2B,and 5-HT2c.All 5-HT2 receptors exhibit 46%-50%overall sequence identity,and all of these receptors preferentially bind to Gq/11 to increase inositol phosphates and intracellular calcium mobilization[5].5-HT2B receptors are widely expressed throughout the gut,and experimental evidence suggests that the primary function of 5-HT2B receptors is to mediate contractile responses to 5-HT through its action on smooth muscle[6].The 5-HT2B receptor is localized to both neurons of the myenteric nerve plexus and smooth muscle in the human colon.The 5-HT2B receptor mediates 5-HT-evoked contraction of longitudinal smooth muscle[6].These findings suggest that the 5-HT2B receptor could play an important role in modulating colonic motility,which could affect sensory signaling in the gut.Other laboratories have shown that the 5-HT2B receptor participates in the development of mechanical and formalin-induced hyperalgesia[7,8].A 5-HT2B receptor antagonist reduced 2,4,6-trinitrobenzene sulfonic acid(TNBS)and stress-induced visceral hyperalgesia in rats[9,10].However,the role of the 5-HT2B receptor in IBS-D patients and in acetic acid-and wrap restraint-induced IBS-D rat models was not investigated.展开更多
AIM: To explore the expression of transient receptor potential vanilloid 4(TRPV4) and its physiological meaning in mouse and rat gastric epithelia. METHODS: RT-PCR and immunochemistry were used to detect TRPV4 m RNA a...AIM: To explore the expression of transient receptor potential vanilloid 4(TRPV4) and its physiological meaning in mouse and rat gastric epithelia. METHODS: RT-PCR and immunochemistry were used to detect TRPV4 m RNA and protein expression in mouse stomach and a rat normal gastric epithelial cell line(RGE1-01), while Ca2+-imaging and electrophysiology were used to evaluate TRPV4 channel activity. ATP release was measured by a luciferin-luciferase assay. Gastric emptying was also compared between WT and TRPV4 knockout mice. RESULTS: TRPV4 m RNA and protein were detected in mouse tissues and RGE1-01 cells. A TRPV4-specific agonist(GSK1016790A) increased intracellular Ca2+ concentrations and/or evoked TRPV4-like current activities in WT mouse gastric epithelial cells andRGE1-01 cells, but not TRPV4 KO cells. GSK1016790 A or mechanical stimuli induced ATP release from RGE1-01 cells while TRPV4 knockout mice displayed delayed gastric emptying in vivo. CONCLUSION: TRPV4 is expressed in mouse and rat gastric epithelium and contributes to ATP release and gastric emptying.展开更多
BACKGROUND Transient receptor potential vanilloid-1(TRPV1),a nonselective cation channel,is activated by capsaicin,a pungent ingredient of hot pepper.Previous studies have suggested a link between obesity and capsaici...BACKGROUND Transient receptor potential vanilloid-1(TRPV1),a nonselective cation channel,is activated by capsaicin,a pungent ingredient of hot pepper.Previous studies have suggested a link between obesity and capsaicin-associated pathways,and activation of TRPV1 may provide an alternative approach for obesity treatment.However,data on the TRPV1 distribution in human gastric mucosa are limited,and the degree of TRPV1 distribution in the gastric and duodenal mucosal cells of obese people in comparison with normal-weight individuals is unknown.AIM To clarify gastric and duodenal mucosal expression of TRPV1 in humans and compare TRPV1 expression in obese and healthy individuals.METHODS Forty-six patients with a body mass index(BMI)of>40 kg/m^(2) and 20 patients with a BMI between 18-25 kg/m^(2) were included.Simultaneous biopsies from the fundus,antrum,and duodenum tissues were obtained from subjects between the ages of 18 and 65 who underwent esophagogastroduodenoscopy.Age,sex,history of alcohol and cigarette consumption,and past medical history regarding chronic diseases and medications were accessed from patient charts and were analyzed accordingly.Evaluation with anti-TRPV1 antibody was performed separately according to cell types in the fundus,antrum,and duodenum tissues using an immunoreactivity score.Data were analyzed using SPSS 17.0.RESULTS TRPV1 expression was higher in the stomach than in the duodenum and was predominantly found in parietal and chief cells of the fundus and mucous and foveolar cells of the antrum.Unlike foveolar cells in the antrum,TRPV1 was relatively low in foveolar cells in the fundus(4.92±0.49 vs 0.48±0.16,P<0.01,Mann-Whitney U test).Additionally,the mucous cells in the duodenum also had low levels of TRPV1 compared to mucous cells in the antrum(1.33±0.31 vs 2.95±0.46,P<0.01,Mann-Whitney U test).TRPV1 expression levels of different cell types in the fundus,antrum,and duodenum tissues of the morbidly obese group were similar to those of the control group.Staining with TRPV1 in fundus chief cells and antrum and duodenum mucous cells was higher in patients aged≥45 years than in patients<45 years(3.03±0.42,4.37±0.76,2.28±0.55 vs 1.9±0.46,1.58±0.44,0.37±0.18,P=0.03,P<0.01,P<0.01,respectively,Mann-Whitney U test).The mean staining levels of TRPV1 in duodenal mucous cells in patients with diabetes and hypertension were higher than those in patients without diabetes and hypertension(diabetes:2.11±0.67 vs 1.02±0.34,P=0.04;hypertension:2.42±0.75 vs 1.02±0.33,P<0.01 Mann-Whitney U test).CONCLUSION The expression of TRPV1 is unchanged in the gastroduodenal mucosa of morbidly obese patients demonstrating that drugs targeting TRPV1 may be effective in these patients.展开更多
●AIM:To explore whether autophagy functions as a cellular adaptation mechanism in lens epithelial cells(LECs)under hyperosmotic stress.●METHODS:LECs were treated with hyperosmotic stress at the concentration of 270,...●AIM:To explore whether autophagy functions as a cellular adaptation mechanism in lens epithelial cells(LECs)under hyperosmotic stress.●METHODS:LECs were treated with hyperosmotic stress at the concentration of 270,300,400,500,or 600 mOsm for 6,12,18,24h in vitro.Polymerase chain reaction(PCR)was employed for the mRNA expression of autophagyrelated genes,while Western blotting detected the targeted protein expression.The transfection of stub-RFP-sens-GFPLC3 autophagy-related double fluorescence lentivirus was conducted to detect the level of autophagy flux.Scanning electron microscopy was used to detect the existence of autolysosome.Short interfering RNA of autophagy-related gene(ATG)7,transient receptor potential vanilloid(TRPV)1 overexpression plasmid,related agonists and inhibitors were employed to their influence on autophagy related pathway.Flow cytometry was employed to test the apoptosis and intracellular Ca^(2+)level.Mitochondrial membrane potential was measured by JC-1 staining.The cell counting kit-8 assay was used to calculate the cellular viability.The wound healing assay was used to evaluate the wound closure rate.GraphPad 6.0 software was utilized to evaluate the data.●RESULTS:The hyperosmotic stress activated autophagy in a pressure-and time-dependent manner in LECs.Beclin 1 protein expression and conversion of LC3B II to LC3B I increased,whereas sequestosome-1(SQSTM1)protein expression decreased.Transient Ca^(2+)influx was stimulated caused by hyperosmotic stress,levels of mammalian target of rapamycin(mTOR)phosphorylation decreased,and the level of AMP-activated protein kinase(AMPK)phosphorylation increased in the early stage.Based on this evidence,autophagy activation through the Ca^(2+)-dependent AMPK/mTOR pathway might represent an adaptation process in LECs under hyperosmotic stress.Hyperosmotic stress decreased cellular viability and accelerated apoptosis in LECs and cellular migration decreased.Inhibition of autophagy by ATG7 knockdown had similar results.TRPV1 overexpression increased autophagy and might be crucial in the occurrence of autophagy promoted by hyperosmotic stress.●CONCLUSION:A combination of hyperosmotic stress and autophagy inhibition may be a promising approach to decrease the number of LECs in the capsular bag and pave the way for improving prevention of posterior capsular opacification and capsular fibrosis.展开更多
The mechanisms of epidural-associated fever remain incompletely understood [1-3]. We propose that action of local anesthetic on TPRV1. The transient receptor potential cation channel subfamily V member 1 (TRPV1), also...The mechanisms of epidural-associated fever remain incompletely understood [1-3]. We propose that action of local anesthetic on TPRV1. The transient receptor potential cation channel subfamily V member 1 (TRPV1), also known as the capsaicin receptor and the vanilloid receptor can explain this effect and explain mechanism of burning sensation on local anesthetic injected subcutaneously or intramuscular. Role of TRPV1 receptor was not discussed previously in Obstetric Anesthesia literature. Based on available data, we propose that Local Anesthetics work as agonist/antagonist on TPRV1 receptors. Antagonist action may cause hyperthermia through modifying thermoregulation [4], agonist action may cause hyperthermia thru release of IL-6 and other mediators of inflammation [5-10]. Agonist action may explain burning sensation on injection of Local Anesthetics. Burning sensation can be diminished by increasing pH of Local Anesthetic solution, because vanillin receptors are stimulated by acidification through lower pH [11,12].展开更多
The transient receptor potential cation channel subfamily V member 1（TRPV1） provides the sensation of pain（nociception）. However, it remains unknown whether TRPV1 is activated after peripheral nerve injury, or whe...The transient receptor potential cation channel subfamily V member 1（TRPV1） provides the sensation of pain（nociception）. However, it remains unknown whether TRPV1 is activated after peripheral nerve injury, or whether activation of TRPV1 affects neural regeneration. In the present study, we established rat models of unilateral sciatic nerve crush injury, with or without pretreatment with AMG517（300 mg/kg）, a TRPV1 antagonist, injected subcutaneously into the ipsilateral paw 60 minutes before injury. At 1 and 2 weeks after injury, we performed immunofluorescence staining of the sciatic nerve at the center of injury, at 0.3 cm proximal and distal to the injury site, and in the dorsal root ganglia. Our results showed that Wallerian degeneration occurred distal to the injury site, and neurite outgrowth and Schwann cell regeneration occurred proximal to the injury. The number of regenerating myelinated and unmyelinated nerve clusters was greater in the AMG517-pretreated rats than in the vehicle-treated group, most notably 2 weeks after injury. TRPV1 expression in the injured sciatic nerve and ipsilateral dorsal root ganglia was markedly greater than on the contralateral side. Pretreatment with AMG517 blocked this effect. These data indicate that TRPV1 is activated or overexpressed after sciatic nerve crush injury, and that blockade of TRPV1 may accelerate regeneration of the injured sciatic nerve.展开更多
基金the National Natural Science Foundation of China (General Program),No. 30872732the National Natural Science Foundation of China for Youths,No.81101453
文摘Dorsal root ganglion （DRG） neurons from newborn Wistar rats cultured in vitro were pressurized with 20, 40, 80 or 120 mm Hg compressive Ioadings （1 mm Hg = 0.133 kPa） for 12, 24, 48 or 72 hours, respectively. The 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide test showed that pressures less than 80 mm Hg had no obvious impact on the activity of DRG neurons. The protein expression levels of transient receptor potential vanilloid receptor 4 （TRPV4）, transient receptor potential vanilloid receptor 1, transient receptor potential channel of melastatin type 8, and transient receptor potential subtype ankyrin 1 were assessed by western blot analysis. The mRNA expression of TRPV4 was assessed by real-time PCR. The results showed that sustained mechanical compression up-regulated TRPV4 mRNA and protein expression in the rat DRG neurons, in a time-dependent fashion. Similar changes were not found in the protein expression of transient receptor potential vanilloid receptor 1, transient receptor potential channel of melastatin type 8, and transient receptor potential subtype ankyrin 1. Images of cells using a laser scanning confocal microscope showed that the sustained mechanical pressure increased the number of responsive DRG neurons and was synergistic on the enhanced Ca^2＋ responses to the TRPV4 phorbol ester agonist 4a-phorbo112, 13-didecanoate and hypotonic solutions. These findings demonstrate that sustained mechanical compressive loading in vitro increases the expression of TRPV4 mRNA and protein in DRG neurons and sensitizes TRPV4 Ca^2＋ signals. Mechanical compression does not impact other ion channels in the transient receptor potential family.
基金The Health Commission of Jinshan District,Shanghai,China,No.JSKJ-KTMS-2019-01The Youth Research Foundation of Jinshan Hospital of Fudan University,No.JYQN-JC-202101 and No.JYQN-JC-202216The Reserve Discipline Construction of Jinshan Hospital of Fudan University,No.HBXK-2021-2.
文摘BACKGROUND Serotonin receptor 2B(5-HT2B receptor)plays a critical role in many chronic pain conditions.The possible involvement of the 5-HT2B receptor in the altered gut sensation of irritable bowel syndrome with diarrhea(IBS-D)was investigated in the present study.AIM To investigate the possible involvement of 5-HT2B receptor in the altered gut sensation in rat model and patients with IBS-D.METHODS Rectosigmoid biopsies were collected from 18 patients with IBS-D and 10 patients with irritable bowel syndrome with constipation who fulfilled the Rome IV criteria and 15 healthy controls.The expression level of the 5-HT2B receptor in colon tissue was measured using an enzyme-linked immunosorbent assay and correlated with abdominal pain scores.The IBS-D rat model was induced by intracolonic instillation of acetic acid and wrap restraint.Alterations in visceral sensitivity and 5-HT2B receptor and transient receptor potential vanilloid type 1(TRPV1)expression were examined following 5-HT2B receptor antagonist adminis-tration.Changes in visceral sensitivity after administration of the TRPV1 antago-INTRODUCTION Irritable bowel syndrome(IBS)is a chronic functional bowel disorder characterized by recurrent abdominal pain with altered bowel habits that affects approximately 15%of the population worldwide[1].IBS significantly impacts the quality of life of patients.Although the pathogenesis of IBS is not completely understood,the role of abnormal visceral sensitivity in IBS has recently emerged[2,3].5-Hydroxytryptamine(5-HT)is known to play a key role in the physiological states of the gastrointestinal tract.Plasma 5-HT levels in IBS with diarrhea(IBS-D)patients were greater than those in healthy controls[4],suggesting a possible role of 5-HT in the pathogenesis of IBS-D.The serotonin receptor 2(5-HT2 receptor)family comprises three subtypes:5-HT2A,5-HT2B,and 5-HT2c.All 5-HT2 receptors exhibit 46%-50%overall sequence identity,and all of these receptors preferentially bind to Gq/11 to increase inositol phosphates and intracellular calcium mobilization[5].5-HT2B receptors are widely expressed throughout the gut,and experimental evidence suggests that the primary function of 5-HT2B receptors is to mediate contractile responses to 5-HT through its action on smooth muscle[6].The 5-HT2B receptor is localized to both neurons of the myenteric nerve plexus and smooth muscle in the human colon.The 5-HT2B receptor mediates 5-HT-evoked contraction of longitudinal smooth muscle[6].These findings suggest that the 5-HT2B receptor could play an important role in modulating colonic motility,which could affect sensory signaling in the gut.Other laboratories have shown that the 5-HT2B receptor participates in the development of mechanical and formalin-induced hyperalgesia[7,8].A 5-HT2B receptor antagonist reduced 2,4,6-trinitrobenzene sulfonic acid(TNBS)and stress-induced visceral hyperalgesia in rats[9,10].However,the role of the 5-HT2B receptor in IBS-D patients and in acetic acid-and wrap restraint-induced IBS-D rat models was not investigated.
基金Supported by Grants from the University of Toyama and JSPS KAKENHI to Mihara H,No.26870214
文摘AIM: To explore the expression of transient receptor potential vanilloid 4(TRPV4) and its physiological meaning in mouse and rat gastric epithelia. METHODS: RT-PCR and immunochemistry were used to detect TRPV4 m RNA and protein expression in mouse stomach and a rat normal gastric epithelial cell line(RGE1-01), while Ca2+-imaging and electrophysiology were used to evaluate TRPV4 channel activity. ATP release was measured by a luciferin-luciferase assay. Gastric emptying was also compared between WT and TRPV4 knockout mice. RESULTS: TRPV4 m RNA and protein were detected in mouse tissues and RGE1-01 cells. A TRPV4-specific agonist(GSK1016790A) increased intracellular Ca2+ concentrations and/or evoked TRPV4-like current activities in WT mouse gastric epithelial cells andRGE1-01 cells, but not TRPV4 KO cells. GSK1016790 A or mechanical stimuli induced ATP release from RGE1-01 cells while TRPV4 knockout mice displayed delayed gastric emptying in vivo. CONCLUSION: TRPV4 is expressed in mouse and rat gastric epithelium and contributes to ATP release and gastric emptying.
文摘BACKGROUND Transient receptor potential vanilloid-1(TRPV1),a nonselective cation channel,is activated by capsaicin,a pungent ingredient of hot pepper.Previous studies have suggested a link between obesity and capsaicin-associated pathways,and activation of TRPV1 may provide an alternative approach for obesity treatment.However,data on the TRPV1 distribution in human gastric mucosa are limited,and the degree of TRPV1 distribution in the gastric and duodenal mucosal cells of obese people in comparison with normal-weight individuals is unknown.AIM To clarify gastric and duodenal mucosal expression of TRPV1 in humans and compare TRPV1 expression in obese and healthy individuals.METHODS Forty-six patients with a body mass index(BMI)of>40 kg/m^(2) and 20 patients with a BMI between 18-25 kg/m^(2) were included.Simultaneous biopsies from the fundus,antrum,and duodenum tissues were obtained from subjects between the ages of 18 and 65 who underwent esophagogastroduodenoscopy.Age,sex,history of alcohol and cigarette consumption,and past medical history regarding chronic diseases and medications were accessed from patient charts and were analyzed accordingly.Evaluation with anti-TRPV1 antibody was performed separately according to cell types in the fundus,antrum,and duodenum tissues using an immunoreactivity score.Data were analyzed using SPSS 17.0.RESULTS TRPV1 expression was higher in the stomach than in the duodenum and was predominantly found in parietal and chief cells of the fundus and mucous and foveolar cells of the antrum.Unlike foveolar cells in the antrum,TRPV1 was relatively low in foveolar cells in the fundus(4.92±0.49 vs 0.48±0.16,P<0.01,Mann-Whitney U test).Additionally,the mucous cells in the duodenum also had low levels of TRPV1 compared to mucous cells in the antrum(1.33±0.31 vs 2.95±0.46,P<0.01,Mann-Whitney U test).TRPV1 expression levels of different cell types in the fundus,antrum,and duodenum tissues of the morbidly obese group were similar to those of the control group.Staining with TRPV1 in fundus chief cells and antrum and duodenum mucous cells was higher in patients aged≥45 years than in patients<45 years(3.03±0.42,4.37±0.76,2.28±0.55 vs 1.9±0.46,1.58±0.44,0.37±0.18,P=0.03,P<0.01,P<0.01,respectively,Mann-Whitney U test).The mean staining levels of TRPV1 in duodenal mucous cells in patients with diabetes and hypertension were higher than those in patients without diabetes and hypertension(diabetes:2.11±0.67 vs 1.02±0.34,P=0.04;hypertension:2.42±0.75 vs 1.02±0.33,P<0.01 Mann-Whitney U test).CONCLUSION The expression of TRPV1 is unchanged in the gastroduodenal mucosa of morbidly obese patients demonstrating that drugs targeting TRPV1 may be effective in these patients.
文摘●AIM:To explore whether autophagy functions as a cellular adaptation mechanism in lens epithelial cells(LECs)under hyperosmotic stress.●METHODS:LECs were treated with hyperosmotic stress at the concentration of 270,300,400,500,or 600 mOsm for 6,12,18,24h in vitro.Polymerase chain reaction(PCR)was employed for the mRNA expression of autophagyrelated genes,while Western blotting detected the targeted protein expression.The transfection of stub-RFP-sens-GFPLC3 autophagy-related double fluorescence lentivirus was conducted to detect the level of autophagy flux.Scanning electron microscopy was used to detect the existence of autolysosome.Short interfering RNA of autophagy-related gene(ATG)7,transient receptor potential vanilloid(TRPV)1 overexpression plasmid,related agonists and inhibitors were employed to their influence on autophagy related pathway.Flow cytometry was employed to test the apoptosis and intracellular Ca^(2+)level.Mitochondrial membrane potential was measured by JC-1 staining.The cell counting kit-8 assay was used to calculate the cellular viability.The wound healing assay was used to evaluate the wound closure rate.GraphPad 6.0 software was utilized to evaluate the data.●RESULTS:The hyperosmotic stress activated autophagy in a pressure-and time-dependent manner in LECs.Beclin 1 protein expression and conversion of LC3B II to LC3B I increased,whereas sequestosome-1(SQSTM1)protein expression decreased.Transient Ca^(2+)influx was stimulated caused by hyperosmotic stress,levels of mammalian target of rapamycin(mTOR)phosphorylation decreased,and the level of AMP-activated protein kinase(AMPK)phosphorylation increased in the early stage.Based on this evidence,autophagy activation through the Ca^(2+)-dependent AMPK/mTOR pathway might represent an adaptation process in LECs under hyperosmotic stress.Hyperosmotic stress decreased cellular viability and accelerated apoptosis in LECs and cellular migration decreased.Inhibition of autophagy by ATG7 knockdown had similar results.TRPV1 overexpression increased autophagy and might be crucial in the occurrence of autophagy promoted by hyperosmotic stress.●CONCLUSION:A combination of hyperosmotic stress and autophagy inhibition may be a promising approach to decrease the number of LECs in the capsular bag and pave the way for improving prevention of posterior capsular opacification and capsular fibrosis.
文摘The mechanisms of epidural-associated fever remain incompletely understood [1-3]. We propose that action of local anesthetic on TPRV1. The transient receptor potential cation channel subfamily V member 1 (TRPV1), also known as the capsaicin receptor and the vanilloid receptor can explain this effect and explain mechanism of burning sensation on local anesthetic injected subcutaneously or intramuscular. Role of TRPV1 receptor was not discussed previously in Obstetric Anesthesia literature. Based on available data, we propose that Local Anesthetics work as agonist/antagonist on TPRV1 receptors. Antagonist action may cause hyperthermia through modifying thermoregulation [4], agonist action may cause hyperthermia thru release of IL-6 and other mediators of inflammation [5-10]. Agonist action may explain burning sensation on injection of Local Anesthetics. Burning sensation can be diminished by increasing pH of Local Anesthetic solution, because vanillin receptors are stimulated by acidification through lower pH [11,12].
基金supported by the National Natural Science Foundation of China,No.81171178the Natural Science Foundation of Shanxi Province in China,No.2012011036-3Scientific Research Foundation of Shanxi Province of China for the Returned Overseas Chinese Scholars,No.2013011054-2
文摘The transient receptor potential cation channel subfamily V member 1（TRPV1） provides the sensation of pain（nociception）. However, it remains unknown whether TRPV1 is activated after peripheral nerve injury, or whether activation of TRPV1 affects neural regeneration. In the present study, we established rat models of unilateral sciatic nerve crush injury, with or without pretreatment with AMG517（300 mg/kg）, a TRPV1 antagonist, injected subcutaneously into the ipsilateral paw 60 minutes before injury. At 1 and 2 weeks after injury, we performed immunofluorescence staining of the sciatic nerve at the center of injury, at 0.3 cm proximal and distal to the injury site, and in the dorsal root ganglia. Our results showed that Wallerian degeneration occurred distal to the injury site, and neurite outgrowth and Schwann cell regeneration occurred proximal to the injury. The number of regenerating myelinated and unmyelinated nerve clusters was greater in the AMG517-pretreated rats than in the vehicle-treated group, most notably 2 weeks after injury. TRPV1 expression in the injured sciatic nerve and ipsilateral dorsal root ganglia was markedly greater than on the contralateral side. Pretreatment with AMG517 blocked this effect. These data indicate that TRPV1 is activated or overexpressed after sciatic nerve crush injury, and that blockade of TRPV1 may accelerate regeneration of the injured sciatic nerve.
