The prevalence of FGID in adolescents was relatively high. The presences of FGID worsen the QOSL score. Medical intervention and/or counseling are needed for such students to improve the QOSL.
ObjectivesIt is controversial whether sodium glucose transporter (SGLT) 2 inhibitors increase glucagon secretion via direct inhibition of SGLT2 in pancreatic α cells. The role of SGLT1 in α cells is also unclear. We aimed to elucidate these points that are important not only for basic research but also for clinical insight.MethodsPlasma glucagon levels were assessed in the high-fat, high-sucrose diet (HFHSD) fed C57BL/6J mice treated with dapagliflozin or canagliflozin. RT-PCR, RNA sequence, and immunohistochemistry were conducted to test the expression of SGLT1 and SGLT2 in α cells. We also used αTC1 cells and mouse islets to investigate the molecular mechanism by which SGLT1 modulates glucagon secretion.ResultsDapagliflozin, but not canagliflozin, increased plasma glucagon levels in HFHSD fed mice. SGLT1 and glucose transporter 1 (GLUT1), but not SGLT2, were expressed in αTC1 cells, mouse islets and human islets. A glucose clamp study revealed that the plasma glucagon increase associated with dapagliflozin could be explained as a response to acute declines in blood glucose. Canagliflozin suppressed glucagon secretion by inhibiting SGLT1 in α cells; consequently, plasma glucagon did not increase with canagliflozin, even though blood glucose declined. SGLT1 effect on glucagon secretion depended on glucose transport, but not glucose metabolism. Islets from HFHSD and db/db mice displayed higher SGLT1 mRNA levels and lower GLUT1 mRNA levels than the islets from control mice. These expression levels were associated with higher glucagon secretion. Furthermore, SGLT1 inhibitor and siRNA against SGLT1 suppressed glucagon secretion in isolated islets.ConclusionsThese data suggested that a novel mechanism regulated glucagon secretion through SGLT1 in α cells. This finding possibly explained the distinct effects of dapagliflozin and canagliflozin on plasma glucagon levels in mice.
Background and aims: Induction of apoptosis of cancer cells through ligands of nuclear hormone receptors (NHRs) is a new approach in cancer therapy. Recently, one of the NHRs, peroxisome proliferator activated receptor γ (PPARγ), has been shown to influence cell growth in certain cancer cells although its effect on hepatocellular carcinoma (HCC) has not been analysed. Methods: Experiments were conducted using three human liver cancer cell lines, PLC/PRF/5, Hep G2 and HuH-7, in vitro. These cells were exposed to troglitazone, a synthetic ligand for PPARγ, and the effects on cell growth were analysed. Results: Expression of PPARγ mRNA was detected in all three liver cancer cell lines. Activation of PPARγ by troglitazone caused a marked growth inhibition in a dose dependent manner in three hepatoma cell lines. The DNA fragmentation ELISA assay and Hoechst 33258 staining revealed that the growth inhibitory effect by adding troglitazone was due to apoptosis of PLC/PRF/5, which strongly expressed PPARγ. Troglitazone also induced activation of the cell death protease, caspase 3, but not caspase 8, in PLC/PRF/5 cells. However, expression levels of antiapoptotic factor bcl-2 and apoptosis inducing factor bax were not affected. Conclusion: Our study showed that PPARγ was expressed in human liver cancer cells and that the ligand for PPARγ, troglitazone, inhibited the growth of these cells by inducing apoptosis through caspase 3 activation, indicating that troglitazone could be potentially useful as an apoptosis inducer for the treatment of HCC.
The constitutive active receptor (CAR) regulates the induction of the cytochrome P450 2B6 (CYP2B6) gene by phenobarbital-type inducers, such as 1,4 bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) via the distal phenobarbital-responsive enhancer module (PBREM, at ؊1732/؊1685 bp). Activation of the PBREM by TCPOBOP generated a 10-fold induction of CYP2B6 mRNA in HepG2 cells stably expressing mouse CAR (Ym17). Co-treatment with the protein phosphatase inhibitor okadaic acid (OA) synergistically increased this induction over 100-fold without directly activating CAR or the PBREM. Although OA synergy required the presence of PBREM, deletion assays delineated the OA-responsive activity to a proximal 24-bp (؊256/؊233) sequence (OARE) in the CYP2B6 promoter. CAR did not directly bind to the OARE in electrophoretic mobility shift assays. However, both DNA affinity and chromatin immunoprecipitation assays showed a significant increase in CAR association with the OARE after co-treatment with TCPOBOP and OA, indicating the indirect binding of CAR to the OARE. The two cis-acting elements, the distal PBREM and the proximal OARE, within the chromatin structure are both regulated by CAR in response to TCPOBOP and OA, respectively, to maximally induce the CYP2B6 promoter. This functional interaction between the two sites expands the current understanding of the mechanism of CAR-mediated inducible transcription.
More severe liver disease can be suspected or ruled out based on factors identified in this study. Utilisation of structured lifestyle program, vitamin E and pioglitazone was limited despite this being a cohort of biopsy-proven NAFLD patients with majority of patients having NASH.
Background: Non-alcoholic fatty liver disease is a common liver injury, but the pathophysiological mechanisms leading to the development of non-alcoholic steatohepatitis (NASH) remain unclear. The pathological roles of the nuclear receptor constitutive androstane receptor (CAR), a key regulator of drugmetabolising enzymes, in the development of NASH were investigated. Methods and results: CAR +/+ and CAR 2/2 mice were given a methionine and choline-deficient (MCD) diet to establish a dietary model of NASH. Increases in serum alanine aminotransferase (ALT) and in infiltration of inflammatory cells were dominant in CAR +/+ mice at 8 weeks. There was no significant difference in the lipid concentration of the liver-namely, the first hit between CAR +/+ and CAR 2/2 mice. The index of lipid peroxidation increased in liver of the CAR +/+ mice, as demonstrated by 8-iso-prostaglandin F2a (F2-isoprostanes). Western blotting analysis showed that nuclear translocation of CAR occurred in CAR +/+ mice fed the MCD diet. As a result, the CAR activation caused the lipid peroxidation-namely, the second hit. The expressions of cytochrome P450 (CYP)2B10, 2C29, 3A11 all increased considerably in the CAR +/+ mice. Furthermore, a smooth muscle actin immunohistochemistry and Sirius red staining showed an increase in the degree of fibrosis in CAR +/+ mice fed the MCD diet at 16 weeks. The mRNA expressions of collagen a1(1) and the tissue inhibitor of metalloproteinase-1 were found to be elevated in CAR +/+ mice. Conclusion: CAR caused the worsening of the hepatic injury and fibrosis in the dietary model of NASH. Our results suggest that the CAR nuclear receptor may thus play a critical role in the pathogenesis of NASH.
Nine patients with hepatocellular carcinoma (HCC) in nonalcoholic steatohepatitis (NASH) (six men and three women, median age 71.5 years) and one patient with intrahepatic cholangiocarcinoma (ICC), a 50-year-old man, in NASH are described. Most patients were associated with obesity, diabetes, hypertension, hypercholesterolemia, or hypertriglyceridemia. Seven patients showed insulin resistance and hyperinsulinemia. All patients except one met the criteria for metabolic syndrome. An HCC or ICC diagnosis was confirmed by tumor biopsy, surgery or autopsy except in two patients, who were diagnosed by computed tomography or hepatic angiography. The underlying liver disease was liver cirrhosis in six patients and chronic liver disease including mild hepatic fibrosis in four patients. The treatment of liver cancers consisted of surgery, radio-frequency ablation (RFA), transcatheter arterial embolization and transcatheter arterial infusion. Although the follow-up period was relatively short (median 27.5 months, average 32.1 months), all postoperative and post-RFA patients have not had a recurrence of HCC to date, except for one patient who had a palliative operation with intra-arterial infusion of anticancer drugs through an implanted reservoir port. Older age and liver cirrhosis are considered risk factors for HCC in NASH, and regular screening of these patients is necessary. Diabetes may contribute to the development of ICC in NASH. Curative therapy (surgery or RFA) and weight loss by the active therapeutic intervention (nutritional care and exercise therapy) after curative therapy may help us improve the prognosis of HCC in NASH.
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