BACKGROUND ATP sensitive K+(K_(ATP))channels are ubiquitously distributed in various of cells and tissues,including the liver.They play a role in the pathogenesis of myocardial and liver ischemia.AIM To evaluate the r...BACKGROUND ATP sensitive K+(K_(ATP))channels are ubiquitously distributed in various of cells and tissues,including the liver.They play a role in the pathogenesis of myocardial and liver ischemia.AIM To evaluate the radiation-induced changes in the expression of K_(ATP)channel subunits in the mouse liver to understand the potential role of K_(ATP)channels in radiation injury.METHODS Adult C57BL/6 mice were randomly exposed toγ-rays at 0 Gy(control,n=2),0.2 Gy(n=6),1 Gy(n=6),or 5 Gy(n=6).The livers were removed 3 and 24 h after radiation exposure.Hematoxylin and eosin staining was used for morphological observation;immunohistochemical staining was applied to determine the expression of K_(ATP)channel subunits in the liver tissue.RESULTS Compared with the control group,the livers exposed to 0.2 Gyγ-ray showed an initial increase in the expression of Kir6.1 at 3 h,followed by recovery at 24 h after exposure.Exposure to a high dose of 5.0 Gy resulted in decreased expression of Kir6.1 and increased expression of SUR2B at 24 h.However,the expression of Kir6.2,SUR1,or SUR2A had no remarkable changes at 3 and 24 h after exposure to any of these doses.CONCLUSION The expression levels of Kir6.1 and SUR2B in mouse liver changed differently in response to different radiation doses,suggesting a potential role for them in radiation-induced liver injury.展开更多
To evaluate a calcium activated potassium channel (KCa3.1) inhibitor attenuates liver disease in models of non-alcoholic fatty liver disease (NAFLD).METHODSWe have performed a series of in vitro and in vivo studies us...To evaluate a calcium activated potassium channel (KCa3.1) inhibitor attenuates liver disease in models of non-alcoholic fatty liver disease (NAFLD).METHODSWe have performed a series of in vitro and in vivo studies using the KCa3.1 channel inhibitor, Senicapoc. Efficacy studies of Senicapoc were conducted in toxin-, thioacetamide (TAA) and high fat diet (HFD)-induced models of liver fibrosis in rats. Efficacy and pharmacodynamic effects of Senicapoc was determined through biomarkers of apoptosis, inflammation, steatosis and fibrosis.RESULTSUpregulation of KCa3.1 expression was recorded in TAA-induced and high fat diet-induced liver disease. Treatment with Senicapoc decreased palmitic acid-driven HepG2 cell death. (P < 0.05 vs control) supporting the finding that Senicapoc reduces lipid-driven apoptosis in HepG2 cell cultures. In animals fed a HFD for 6 wk, co-treatment with Senicapoc, (1) reduced non-alcoholic fatty liver disease (NAFLD) activity score (NAS) (0-8 scale), (2) decreased steatosis and (3) decreased hepatic lipid content (Oil Red O, P < 0.05 vs vehicle). Randomization of TAA animals and HFD fed animals to Senicapoc was associated with a decrease in liver fibrosis as evidenced by hydroxyproline and Masson’s trichrome staining (P < 0.05 vs vehicle). These results demonstrated that Senicapoc mitigates both steatosis and fibrosis in liver fibrosis models.CONCLUSIONThese data suggest that Senicapoc interrupts more than one node in progressive fatty liver disease by its anti-steatotic and anti-fibrotic activities, serving as a double-edged therapeutic sword.展开更多
BACKGROUND ATP-sensitive K^+(KATP)channels were originally found in cardiac myocytes by Noma in 1983.KATP channels were formed by potassium ion-passing poreforming subunits(Kir6.1,Kir6.2)and regulatory subunits SUR1,S...BACKGROUND ATP-sensitive K^+(KATP)channels were originally found in cardiac myocytes by Noma in 1983.KATP channels were formed by potassium ion-passing poreforming subunits(Kir6.1,Kir6.2)and regulatory subunits SUR1,SU2A and SUR2B.A number of cells and tissues have been revealed to contain these channels including hepatocytes,but detailed localization of these subunits in different types of liver cells was still uncertain.AIM To investigate the expression of KATP channel subunits in rat liver and their localization in different cells of the liver.METHODS Rabbit anti-rat SUR1 peptide antibody was raised and purified by antigen immunoaffinity column chromatography.Four of Sprague-Dawley rats were used for liver protein extraction for immunoblot analysis,seven of them were used for immunohistochemistry both for the ABC method and immunofluorescence staining.Four of Wistar rats were used for the isolation of hepatic stellate cells(HSCs)and Kupffer cells for both primary culture and immunocytochemistry.RESULTS Immunoblot analysis showed that the five kinds of KATP channel subunits,i.e.Kir6.1,Kir6.2,SUR1,SUR2A,and SUR2B,were detected in liver.Immunohistochemical staining showed that Kir6.1 and Kir6.2 were weakly to moderately expressed in parenchymal cells and sinusoidal lining cells,while SUR1,SUR2A,and SUR2B were mainly localized to sinusoidal lining cells,such as HSCs,Kupffer cells,and sinusoidal endothelial cells.Immunoreactivity for SUR2A and SUR2B was expressed in the hepatocyte membrane.Double immunofluorescence staining further showed that the pore-forming subunits Kir6.1 and/or Kir6.2 colocalized with GFAP in rat liver sections and primary cultured HSCs.These KATP channel subunits also colocalized with CD68 in liver sections and primary cultured Kupffer cells.The SUR subunits colocalized with GFAP in liver sections and colocalized with CD68 both in liver sections and primary cultured Kupffer cells.In addition,five KATP channel subunits colocalized with SE-1 in sinusoidal endothelial cells.CONCLUSION Observations from the present study indicated that KATP channel subunits expressed in rat liver and the diversity of KATP channel subunit composition might form different types of KATP channels.This is applicable to hepatocytes,HSCs,various types of Kupffer cells and sinusoidal endothelial cells.展开更多
Nonalcoholic fatty liver disease (NAFLD) is a group of diseases with excess fat in liver in the absence of a poorly defined limit of alcohol consumption. Most common variety, a universal public health problem, is asso...Nonalcoholic fatty liver disease (NAFLD) is a group of diseases with excess fat in liver in the absence of a poorly defined limit of alcohol consumption. Most common variety, a universal public health problem, is associated with insulin resistance caused by a host of genetic and epigenetic defects modulated by life style and environmental factors. In fact the term NAFLD is loose to incorporate so many etiologies except alcoholism and few other etiologies, presenting as fat in liver. However as a sign fatty liver is very important in predicting the risk of diabetes, cardiovascular disease, stroke, cirrhosis and cancer. Abnormal fat accumulation can result from several defects in nuclear receptors associated with lipid sensing, synthesis and oxidation like LXR, FXR, SREBP, ChREBP and PPAR; defects in the lipid influx-efflux channels, insulin signaling, proteins involved in fatty acid catabolism, defects in adipose tissue development and function, inappropriate nutrition and finally defects in neural regulatory mechanisms. The progress of the disease is determined by the basic defects which results in fat accumulation, an individual’s immunological response to the accumulated fat and its derivatives and the oxidant stress response. Congregation of unrelated genetic defects under same diagnosis ‘NAFLD’ can result in inefficient patient management. Further studies are required to understand the molecular basis of fatty liver to enable a personalized management of diseases presenting as fatty liver in the absence of alcohol abuse.展开更多
In order to solve the problem of intraperitoneal haemorrhage and bile leakage caused by the iatrogenic trauma, sixty-four sequence of puncture were performed on twenty canine livers and thirty-two sequences selected b...In order to solve the problem of intraperitoneal haemorrhage and bile leakage caused by the iatrogenic trauma, sixty-four sequence of puncture were performed on twenty canine livers and thirty-two sequences selected by chance were perfused with thrombin solution. The results revealed that the bleeding time was shortened and amounts lessened significantly after application of thrombin compared with counterparts of control (P< 0. 001,t test).There was no significant difference between the levels of plasma fibringgeu prc-and Post-thrombin's using (P > 0.4,t test).The thrombin clotting time of patients with obstructive jaundice was similar to that of the group of control(P> 0. 05, t test).We conclude that thrombin is characterized by the ability of rapid,effective and safe haemostasis to the traumatic channel made by the liver puncture,and it's adaptive to most of the patients with hepatobiliary disease,and worth using and developing in clinical practice.展开更多
The objectives of this study were as follows: 1) to establish a baseline ethoxyresorufin-O-deethylase (EROD) activity level in channel catfish (Ictalurus punctatus), 2) to assess changes in induction of cytochrome P45...The objectives of this study were as follows: 1) to establish a baseline ethoxyresorufin-O-deethylase (EROD) activity level in channel catfish (Ictalurus punctatus), 2) to assess changes in induction of cytochrome P450 enzyme in channel catfish following exposure to creek water at the discharge point from the Troy (Alabama) Wastewater Treatment Plant (TWWTP) compared to upstream samples from Walnut Creek, 3) to compare EROD activity in populations maintained in laboratory and field settings, and 4) to quantify cytochrome P450 gene expression. Enzyme activity was measured fluorometrically and CYP1 gene expression was analyzed by quantitative real-time reverse transcription polymerase chain reaction. A mean EROD baseline was established at 0.03 nmol/min/μg of protein. The overall mean field effluent (TF) EROD had a significant 5-fold increase over field upstream (UF) exposed catfish;and overall mean laboratory effluent (TL) exposed catfish EROD had a significant 1.8-fold increase over laboratory upstream (UL) exposed catfish. Field exposures generally showed more robust enzyme induction over laboratory exposures on all sampling days. Ex- pression of the CYP1B gene following TF exposure was 6-fold over UF. Results suggested that in situ exposure to wastewater pollutants using caged test organisms provided a much more sensitive local monitor of pollutant exposure and biological impact than ex situ toxicological studies.展开更多
基金Supported by the Program of the Network-type Joint Usage/Research Center for Radiation Disaster Medical Science of Hiroshima University,Nagasaki University.
文摘BACKGROUND ATP sensitive K+(K_(ATP))channels are ubiquitously distributed in various of cells and tissues,including the liver.They play a role in the pathogenesis of myocardial and liver ischemia.AIM To evaluate the radiation-induced changes in the expression of K_(ATP)channel subunits in the mouse liver to understand the potential role of K_(ATP)channels in radiation injury.METHODS Adult C57BL/6 mice were randomly exposed toγ-rays at 0 Gy(control,n=2),0.2 Gy(n=6),1 Gy(n=6),or 5 Gy(n=6).The livers were removed 3 and 24 h after radiation exposure.Hematoxylin and eosin staining was used for morphological observation;immunohistochemical staining was applied to determine the expression of K_(ATP)channel subunits in the liver tissue.RESULTS Compared with the control group,the livers exposed to 0.2 Gyγ-ray showed an initial increase in the expression of Kir6.1 at 3 h,followed by recovery at 24 h after exposure.Exposure to a high dose of 5.0 Gy resulted in decreased expression of Kir6.1 and increased expression of SUR2B at 24 h.However,the expression of Kir6.2,SUR1,or SUR2A had no remarkable changes at 3 and 24 h after exposure to any of these doses.CONCLUSION The expression levels of Kir6.1 and SUR2B in mouse liver changed differently in response to different radiation doses,suggesting a potential role for them in radiation-induced liver injury.
文摘To evaluate a calcium activated potassium channel (KCa3.1) inhibitor attenuates liver disease in models of non-alcoholic fatty liver disease (NAFLD).METHODSWe have performed a series of in vitro and in vivo studies using the KCa3.1 channel inhibitor, Senicapoc. Efficacy studies of Senicapoc were conducted in toxin-, thioacetamide (TAA) and high fat diet (HFD)-induced models of liver fibrosis in rats. Efficacy and pharmacodynamic effects of Senicapoc was determined through biomarkers of apoptosis, inflammation, steatosis and fibrosis.RESULTSUpregulation of KCa3.1 expression was recorded in TAA-induced and high fat diet-induced liver disease. Treatment with Senicapoc decreased palmitic acid-driven HepG2 cell death. (P < 0.05 vs control) supporting the finding that Senicapoc reduces lipid-driven apoptosis in HepG2 cell cultures. In animals fed a HFD for 6 wk, co-treatment with Senicapoc, (1) reduced non-alcoholic fatty liver disease (NAFLD) activity score (NAS) (0-8 scale), (2) decreased steatosis and (3) decreased hepatic lipid content (Oil Red O, P < 0.05 vs vehicle). Randomization of TAA animals and HFD fed animals to Senicapoc was associated with a decrease in liver fibrosis as evidenced by hydroxyproline and Masson’s trichrome staining (P < 0.05 vs vehicle). These results demonstrated that Senicapoc mitigates both steatosis and fibrosis in liver fibrosis models.CONCLUSIONThese data suggest that Senicapoc interrupts more than one node in progressive fatty liver disease by its anti-steatotic and anti-fibrotic activities, serving as a double-edged therapeutic sword.
基金Supported by the Program of the network-type joint Usage/Research Center for Radiation Disaster Medical Science of Hiroshima University,Nagasaki University,and Fukushima Medical University
文摘BACKGROUND ATP-sensitive K^+(KATP)channels were originally found in cardiac myocytes by Noma in 1983.KATP channels were formed by potassium ion-passing poreforming subunits(Kir6.1,Kir6.2)and regulatory subunits SUR1,SU2A and SUR2B.A number of cells and tissues have been revealed to contain these channels including hepatocytes,but detailed localization of these subunits in different types of liver cells was still uncertain.AIM To investigate the expression of KATP channel subunits in rat liver and their localization in different cells of the liver.METHODS Rabbit anti-rat SUR1 peptide antibody was raised and purified by antigen immunoaffinity column chromatography.Four of Sprague-Dawley rats were used for liver protein extraction for immunoblot analysis,seven of them were used for immunohistochemistry both for the ABC method and immunofluorescence staining.Four of Wistar rats were used for the isolation of hepatic stellate cells(HSCs)and Kupffer cells for both primary culture and immunocytochemistry.RESULTS Immunoblot analysis showed that the five kinds of KATP channel subunits,i.e.Kir6.1,Kir6.2,SUR1,SUR2A,and SUR2B,were detected in liver.Immunohistochemical staining showed that Kir6.1 and Kir6.2 were weakly to moderately expressed in parenchymal cells and sinusoidal lining cells,while SUR1,SUR2A,and SUR2B were mainly localized to sinusoidal lining cells,such as HSCs,Kupffer cells,and sinusoidal endothelial cells.Immunoreactivity for SUR2A and SUR2B was expressed in the hepatocyte membrane.Double immunofluorescence staining further showed that the pore-forming subunits Kir6.1 and/or Kir6.2 colocalized with GFAP in rat liver sections and primary cultured HSCs.These KATP channel subunits also colocalized with CD68 in liver sections and primary cultured Kupffer cells.The SUR subunits colocalized with GFAP in liver sections and colocalized with CD68 both in liver sections and primary cultured Kupffer cells.In addition,five KATP channel subunits colocalized with SE-1 in sinusoidal endothelial cells.CONCLUSION Observations from the present study indicated that KATP channel subunits expressed in rat liver and the diversity of KATP channel subunit composition might form different types of KATP channels.This is applicable to hepatocytes,HSCs,various types of Kupffer cells and sinusoidal endothelial cells.
文摘Nonalcoholic fatty liver disease (NAFLD) is a group of diseases with excess fat in liver in the absence of a poorly defined limit of alcohol consumption. Most common variety, a universal public health problem, is associated with insulin resistance caused by a host of genetic and epigenetic defects modulated by life style and environmental factors. In fact the term NAFLD is loose to incorporate so many etiologies except alcoholism and few other etiologies, presenting as fat in liver. However as a sign fatty liver is very important in predicting the risk of diabetes, cardiovascular disease, stroke, cirrhosis and cancer. Abnormal fat accumulation can result from several defects in nuclear receptors associated with lipid sensing, synthesis and oxidation like LXR, FXR, SREBP, ChREBP and PPAR; defects in the lipid influx-efflux channels, insulin signaling, proteins involved in fatty acid catabolism, defects in adipose tissue development and function, inappropriate nutrition and finally defects in neural regulatory mechanisms. The progress of the disease is determined by the basic defects which results in fat accumulation, an individual’s immunological response to the accumulated fat and its derivatives and the oxidant stress response. Congregation of unrelated genetic defects under same diagnosis ‘NAFLD’ can result in inefficient patient management. Further studies are required to understand the molecular basis of fatty liver to enable a personalized management of diseases presenting as fatty liver in the absence of alcohol abuse.
文摘In order to solve the problem of intraperitoneal haemorrhage and bile leakage caused by the iatrogenic trauma, sixty-four sequence of puncture were performed on twenty canine livers and thirty-two sequences selected by chance were perfused with thrombin solution. The results revealed that the bleeding time was shortened and amounts lessened significantly after application of thrombin compared with counterparts of control (P< 0. 001,t test).There was no significant difference between the levels of plasma fibringgeu prc-and Post-thrombin's using (P > 0.4,t test).The thrombin clotting time of patients with obstructive jaundice was similar to that of the group of control(P> 0. 05, t test).We conclude that thrombin is characterized by the ability of rapid,effective and safe haemostasis to the traumatic channel made by the liver puncture,and it's adaptive to most of the patients with hepatobiliary disease,and worth using and developing in clinical practice.
文摘The objectives of this study were as follows: 1) to establish a baseline ethoxyresorufin-O-deethylase (EROD) activity level in channel catfish (Ictalurus punctatus), 2) to assess changes in induction of cytochrome P450 enzyme in channel catfish following exposure to creek water at the discharge point from the Troy (Alabama) Wastewater Treatment Plant (TWWTP) compared to upstream samples from Walnut Creek, 3) to compare EROD activity in populations maintained in laboratory and field settings, and 4) to quantify cytochrome P450 gene expression. Enzyme activity was measured fluorometrically and CYP1 gene expression was analyzed by quantitative real-time reverse transcription polymerase chain reaction. A mean EROD baseline was established at 0.03 nmol/min/μg of protein. The overall mean field effluent (TF) EROD had a significant 5-fold increase over field upstream (UF) exposed catfish;and overall mean laboratory effluent (TL) exposed catfish EROD had a significant 1.8-fold increase over laboratory upstream (UL) exposed catfish. Field exposures generally showed more robust enzyme induction over laboratory exposures on all sampling days. Ex- pression of the CYP1B gene following TF exposure was 6-fold over UF. Results suggested that in situ exposure to wastewater pollutants using caged test organisms provided a much more sensitive local monitor of pollutant exposure and biological impact than ex situ toxicological studies.
文摘肝脏是哺乳动物基础代谢产热的关键器官。温敏瞬时受体电位通道蛋白(Thermosensitive transient receptor potential channels,Thermo-TRPs)参与了调控肝细胞的生理功能。为了解Thermo-TRPs是否参与肝脏的代谢产热,以成年布氏田鼠(Lasiopodomys brandtii)为研究对象,测定了不同驯化温度下6种Thermo-TRPs在肝脏中的表达,分析其与肝脏产热相关蛋白和信号通路蛋白的关系。结果显示:(1)与高温组相比,低温增加了肝脏解偶联蛋白1(uncoupling protein 1,UCP1)的表达;而与常温组相比,低温降低了肝脏解偶联蛋白3(uncoupling protein 3,UCP3)的表达;(2)6种Thermo-TRPs均在肝脏中表达,与高温组相比,低温显著降低了TRP vanilloid 4(TRPV4)的表达,同时显著增加了腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)的表达;(3)低温显著增加了布氏田鼠血清三碘甲状腺原氨酸(T_(3))水平,提高了T_(3)/T_(4)比值;T_(3)/T_(4)比值与肝脏UCP1和AMPK呈显著正相关,肝脏中UCP1与TRPM2和AMPK呈显著正相关。这些结果表明,肝脏TRPV4和AMPK可能参与了低温环境中代谢产热等生理功能的调节过程。
