Nonalcoholic fatty liver disease (NAFLD) is the most prevalent cause of chronic liver disease worldwide. NAFLD is considerably more frequent in patients with type 2 diabetes mellitus (T2DM) than in the general populat...Nonalcoholic fatty liver disease (NAFLD) is the most prevalent cause of chronic liver disease worldwide. NAFLD is considerably more frequent in patients with type 2 diabetes mellitus (T2DM) than in the general population and is also more severe histologically in this group. Sodium-glucose co-transporter-2 (SGLT2) inhibitors, the newest class of antidiabetic agents, appear to represent a promising option for the management of NAFLD in patients with T2DM. In a number of studies, treatment with SGLT2 inhibitors resulted in a reduction in hepatic steatosis and in transaminase levels. However, existing studies are small, their follow-up period was short and none evaluated the effects of SGLT2 inhibitors on liver histology. Accordingly, larger studies are needed to verify these preliminary results and define the role of SGLT2 inhibitors in the treatment of NAFLD in patients with T2DM.展开更多
AIM:To investigate the effects of the somatostatin analogue,octreotide,on maltose and sucrase activities and expression of glucose transporter type 2(GLUT2) in obese rat intestinal mucosa.METHODS:We divided 49 Sprague...AIM:To investigate the effects of the somatostatin analogue,octreotide,on maltose and sucrase activities and expression of glucose transporter type 2(GLUT2) in obese rat intestinal mucosa.METHODS:We divided 49 Sprague-Dawley rats into a group of 31 high fat diet-induced obese rats and a group of 18 normal controls.The obese rats were separated into an octreotide treated group of 16 rats and an obese group of 15.The intervention group was injected with octreotide at 40μg/kg body weight every 12 h for 8 d.Rat body weight was measured weekly to calculate Lee's index.After euthanization,maltase and sucrase activities in the small intestine were measuredby activity assays,and the fasting plasma glucose level was measured.The expression of GLUT2 in small intestinal mucosa was analyzed by immunohistochem-istry,reverse transcriptase polymerase chain reaction and Western blotting assays.RESULTS:Body weight,Lee's index,fasting plasma glucose level,maltase activity in small intestinal mucosa,mucosa and apical GLUT2,GLUT2 mRNA and protein expression levels were all significantly higher in the obese group than in the normal control group(605.61±141.00 vs 378.54±111.75,337.61 ±10.82 vs 318.73±20.10,8.60±1.38 vs 7.33± 0.70,156.01±58.81 vs 50.43±30.49,390 744.2 ±62 469.21 vs 170 546.50±50 646.14,26 740.18 ±3809.60 vs 354.98±57.19,0.26±0.11 vs 0.07 ±0.02,and 2.08±0.59 vs 1.27±0.38,respectively,all P<0.01).Sucrase activity did not differ between the two groups.Octreotide intervention significantly decreased the body weight and fasting plasma glucose level of obese rats(508.27±94.39 vs 605.61±141.00,7.58±1.51 vs 8.60±1.38,respectively,all P<0.05).The intestinal mucosa and apical GLUT2,expression of GLUT2 mRNA and protein were also significantly lower in the octreotide intervention group than in the obese group(269 975.2 ±53 730.94 vs 390 744.2±62 469.21,3758.06± 364.51 vs 26 740.18±3809.60,0.08±0.02 vs 0.26± 0.11,and 1.31±0.27 vs 2.08±0.59,respectively,all P<0.01).CONCLUSION:High fat dietinduced obesity is associated with elevated intestinal maltase activity,GLUT2 expression,and permanent apical GLUT2 in the small intestinal mucosa of rats.Octreotide can inhibit these effects.展开更多
BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are gener...BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are generated which activate free fatty acid receptors(FFAR)2 and 3.FFAR2 and FFAR3 genes are abundantly expressed in colonic epithelium and play an important role in the metabolic homeostasis of colonic epithelial cells.Earlier studies point to the involvement of FFAR2 in colorectal carcinogenesis.AIM To understand the role of short chain FFARs in CRC.METHODS Transcriptome analysis console software was used to analyse microarray data from CRC patients and cell lines.We employed short-hairpin RNA mediated down regulation of FFAR2 and FFAR3 genes,which was validated using quantitative real time polymerase chain reaction.Assays for glucose uptake and cyclic adenosine monophosphate(cAMP)generation was done along with immunofluorescence studies to study the effects of FFAR2/FFAR3 knockdown.For measuring cell proliferation,we employed real time electrical impedancebased assay available from xCELLigence.RESULTS Microarray data analysis of CRC patient samples showed a significant down regulation of FFAR2 gene expression.This prompted us to study the FFAR2 in CRC.Since,FFAR3 shares significant structural and functional homology with FFAR2,we knocked down both these receptors in CRC cell line HCT 116.These modified cell lines exhibited higher proliferation rate and were found to have increased glucose uptake as well as increased level of glucose transporter 1.Since,FFAR2 and FFAR3 signal through G protein subunit(Gαi),knockdown of these receptors was associated with increased cAMP.Inhibition of protein kinase A(PKA)did not alter the growth and proliferation of these cells indicating a mechanism independent of cAMP/PKA pathway.CONCLUSION Our results suggest role of FFAR2/FFAR3 genes in increased proliferation of colon cancer cells via enhanced glucose uptake and exclude the role of PKA mediated cAMP signalling.Alternate pathways could be involved that would ultimately result in increased cell proliferation as a result of down regulated FFAR2/FFAR3 genes.This study paves the way to understand the mechanism of action of short chain FFARs in CRC.展开更多
BACKGROUND Uncarboxylated osteocalcin(GluOC)has been reported to improve glucose metabolism,prevent type 2 diabetes,and decrease the severity of obesity in mice with type 2 diabetes.GluOC can increase glucose uptake i...BACKGROUND Uncarboxylated osteocalcin(GluOC)has been reported to improve glucose metabolism,prevent type 2 diabetes,and decrease the severity of obesity in mice with type 2 diabetes.GluOC can increase glucose uptake in a variety of cells.Glucose metabolism is the main source of energy for osteoblast proliferation and differentiation.We hypothesized that decarboxylated osteocalcin(dcOC),a kind of GluOC,can increase glucose uptake in MG63 cells(osteoblast-like osteosarcoma cells)and influence their proliferation and differentiation.AIM To investigate the effects of dcOC on glucose uptake in human osteoblast-like osteosarcoma cells and the possible signaling pathways involved.METHODS MG63 cells(human osteoblast-like osteosarcoma cells)were treated with dcOC(0,0.3,3,10,or 30 ng/mL)for 1 and 72 h,and glucose uptake was measured by flow cytometry.The effect of dcOC on cell proliferation was measured with a CCK-8 assay,and alkaline phosphatase(ALP)enzyme activity was measured.PI3K was inhibited with LY294002,and hypoxia-inducible factor 1 alpha(HIF-1α)was silenced with siRNA.Then,GPRC6A(G protein-coupled receptor family C group 6 subtype A),total Akt,phosphorylated Akt,HIF-1α,and glucose transporter 1(GLUT1)levels were measured by Western blot to elucidate the possible pathways by which dcOC modulates glucose uptake.RESULTS The glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after short-term(1 h)treatment with dcOC at different concentrations(0.3,3,and 10 ng/mL groups,P<0.01;30 ng/mL group,P<0.05).Glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after long-term(72 h)treatment with dcOC at different concentrations(0.3,3,and 10 ng/mL groups,P<0.01;30 ng/mL group,P<0.05).DcOC triggered Akt phosphorylation in a dose-dependent manner,and the most effective stimulatory concentration of dcOC for short-term(1 h)was 3 ng/mL(P<0.01).LY294002 abolished the dcOC-mediated(1 h)promotion of Akt phosphorylation and glucose uptake without affecting GLUT1 protein expression.Long-term dcOC stimulation triggered Akt phosphorylation and increased the protein levels of HIF-1α,GLUT1,and Runx2 in a dose-dependent manner.Inhibition of HIF-1αwith siRNA abolished the dcOC-mediated glucose uptake and substantially decreased GLUT1 protein expression.DcOC interven-tion promoted cell proliferation in a time-and dose-dependent manner as determined by the CCK-8 assay.Treatment with both 3 ng/mL and 10 ng/mL dcOC affected the ALP activity in MG63 cells after 72 h(P<0.01).CONCLUSION Short-and long-term dcOC treatment can increase glucose uptake and affect proliferation and ALP activity in MG63 cells.This effect may occur through the PI3K/Akt,HIF-1α,and GLUT1 signaling factors.展开更多
文摘Nonalcoholic fatty liver disease (NAFLD) is the most prevalent cause of chronic liver disease worldwide. NAFLD is considerably more frequent in patients with type 2 diabetes mellitus (T2DM) than in the general population and is also more severe histologically in this group. Sodium-glucose co-transporter-2 (SGLT2) inhibitors, the newest class of antidiabetic agents, appear to represent a promising option for the management of NAFLD in patients with T2DM. In a number of studies, treatment with SGLT2 inhibitors resulted in a reduction in hepatic steatosis and in transaminase levels. However, existing studies are small, their follow-up period was short and none evaluated the effects of SGLT2 inhibitors on liver histology. Accordingly, larger studies are needed to verify these preliminary results and define the role of SGLT2 inhibitors in the treatment of NAFLD in patients with T2DM.
基金Supported by Grants from the National Natural Sciences Foundation of China,No.30870919Sichuan Provincial Department of Science and Technology,No.2010SZ0176
文摘AIM:To investigate the effects of the somatostatin analogue,octreotide,on maltose and sucrase activities and expression of glucose transporter type 2(GLUT2) in obese rat intestinal mucosa.METHODS:We divided 49 Sprague-Dawley rats into a group of 31 high fat diet-induced obese rats and a group of 18 normal controls.The obese rats were separated into an octreotide treated group of 16 rats and an obese group of 15.The intervention group was injected with octreotide at 40μg/kg body weight every 12 h for 8 d.Rat body weight was measured weekly to calculate Lee's index.After euthanization,maltase and sucrase activities in the small intestine were measuredby activity assays,and the fasting plasma glucose level was measured.The expression of GLUT2 in small intestinal mucosa was analyzed by immunohistochem-istry,reverse transcriptase polymerase chain reaction and Western blotting assays.RESULTS:Body weight,Lee's index,fasting plasma glucose level,maltase activity in small intestinal mucosa,mucosa and apical GLUT2,GLUT2 mRNA and protein expression levels were all significantly higher in the obese group than in the normal control group(605.61±141.00 vs 378.54±111.75,337.61 ±10.82 vs 318.73±20.10,8.60±1.38 vs 7.33± 0.70,156.01±58.81 vs 50.43±30.49,390 744.2 ±62 469.21 vs 170 546.50±50 646.14,26 740.18 ±3809.60 vs 354.98±57.19,0.26±0.11 vs 0.07 ±0.02,and 2.08±0.59 vs 1.27±0.38,respectively,all P<0.01).Sucrase activity did not differ between the two groups.Octreotide intervention significantly decreased the body weight and fasting plasma glucose level of obese rats(508.27±94.39 vs 605.61±141.00,7.58±1.51 vs 8.60±1.38,respectively,all P<0.05).The intestinal mucosa and apical GLUT2,expression of GLUT2 mRNA and protein were also significantly lower in the octreotide intervention group than in the obese group(269 975.2 ±53 730.94 vs 390 744.2±62 469.21,3758.06± 364.51 vs 26 740.18±3809.60,0.08±0.02 vs 0.26± 0.11,and 1.31±0.27 vs 2.08±0.59,respectively,all P<0.01).CONCLUSION:High fat dietinduced obesity is associated with elevated intestinal maltase activity,GLUT2 expression,and permanent apical GLUT2 in the small intestinal mucosa of rats.Octreotide can inhibit these effects.
文摘BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are generated which activate free fatty acid receptors(FFAR)2 and 3.FFAR2 and FFAR3 genes are abundantly expressed in colonic epithelium and play an important role in the metabolic homeostasis of colonic epithelial cells.Earlier studies point to the involvement of FFAR2 in colorectal carcinogenesis.AIM To understand the role of short chain FFARs in CRC.METHODS Transcriptome analysis console software was used to analyse microarray data from CRC patients and cell lines.We employed short-hairpin RNA mediated down regulation of FFAR2 and FFAR3 genes,which was validated using quantitative real time polymerase chain reaction.Assays for glucose uptake and cyclic adenosine monophosphate(cAMP)generation was done along with immunofluorescence studies to study the effects of FFAR2/FFAR3 knockdown.For measuring cell proliferation,we employed real time electrical impedancebased assay available from xCELLigence.RESULTS Microarray data analysis of CRC patient samples showed a significant down regulation of FFAR2 gene expression.This prompted us to study the FFAR2 in CRC.Since,FFAR3 shares significant structural and functional homology with FFAR2,we knocked down both these receptors in CRC cell line HCT 116.These modified cell lines exhibited higher proliferation rate and were found to have increased glucose uptake as well as increased level of glucose transporter 1.Since,FFAR2 and FFAR3 signal through G protein subunit(Gαi),knockdown of these receptors was associated with increased cAMP.Inhibition of protein kinase A(PKA)did not alter the growth and proliferation of these cells indicating a mechanism independent of cAMP/PKA pathway.CONCLUSION Our results suggest role of FFAR2/FFAR3 genes in increased proliferation of colon cancer cells via enhanced glucose uptake and exclude the role of PKA mediated cAMP signalling.Alternate pathways could be involved that would ultimately result in increased cell proliferation as a result of down regulated FFAR2/FFAR3 genes.This study paves the way to understand the mechanism of action of short chain FFARs in CRC.
基金Supported by Provincial Science and Technology Department Natural Fund Guidance Project,No.2019-ZD-0774National Natural Science Foundation of China,No.81470998+1 种基金Liaoning Ministry of Education,No.LQNK201715and Liaoning Provincial Doctor Start up Fund,No.20180540008.
文摘BACKGROUND Uncarboxylated osteocalcin(GluOC)has been reported to improve glucose metabolism,prevent type 2 diabetes,and decrease the severity of obesity in mice with type 2 diabetes.GluOC can increase glucose uptake in a variety of cells.Glucose metabolism is the main source of energy for osteoblast proliferation and differentiation.We hypothesized that decarboxylated osteocalcin(dcOC),a kind of GluOC,can increase glucose uptake in MG63 cells(osteoblast-like osteosarcoma cells)and influence their proliferation and differentiation.AIM To investigate the effects of dcOC on glucose uptake in human osteoblast-like osteosarcoma cells and the possible signaling pathways involved.METHODS MG63 cells(human osteoblast-like osteosarcoma cells)were treated with dcOC(0,0.3,3,10,or 30 ng/mL)for 1 and 72 h,and glucose uptake was measured by flow cytometry.The effect of dcOC on cell proliferation was measured with a CCK-8 assay,and alkaline phosphatase(ALP)enzyme activity was measured.PI3K was inhibited with LY294002,and hypoxia-inducible factor 1 alpha(HIF-1α)was silenced with siRNA.Then,GPRC6A(G protein-coupled receptor family C group 6 subtype A),total Akt,phosphorylated Akt,HIF-1α,and glucose transporter 1(GLUT1)levels were measured by Western blot to elucidate the possible pathways by which dcOC modulates glucose uptake.RESULTS The glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after short-term(1 h)treatment with dcOC at different concentrations(0.3,3,and 10 ng/mL groups,P<0.01;30 ng/mL group,P<0.05).Glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after long-term(72 h)treatment with dcOC at different concentrations(0.3,3,and 10 ng/mL groups,P<0.01;30 ng/mL group,P<0.05).DcOC triggered Akt phosphorylation in a dose-dependent manner,and the most effective stimulatory concentration of dcOC for short-term(1 h)was 3 ng/mL(P<0.01).LY294002 abolished the dcOC-mediated(1 h)promotion of Akt phosphorylation and glucose uptake without affecting GLUT1 protein expression.Long-term dcOC stimulation triggered Akt phosphorylation and increased the protein levels of HIF-1α,GLUT1,and Runx2 in a dose-dependent manner.Inhibition of HIF-1αwith siRNA abolished the dcOC-mediated glucose uptake and substantially decreased GLUT1 protein expression.DcOC interven-tion promoted cell proliferation in a time-and dose-dependent manner as determined by the CCK-8 assay.Treatment with both 3 ng/mL and 10 ng/mL dcOC affected the ALP activity in MG63 cells after 72 h(P<0.01).CONCLUSION Short-and long-term dcOC treatment can increase glucose uptake and affect proliferation and ALP activity in MG63 cells.This effect may occur through the PI3K/Akt,HIF-1α,and GLUT1 signaling factors.
