Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce cardiovascular events in humans with type 2 diabetes (T2D); however, the underlying mechanism remains unclear. Activation of the NLR family, ...pyrin domain-containing 3 (NLRP3) inflammasome and subsequent interleukin (IL)-1β release induces atherosclerosis and heart failure. Here we show the effect of SGLT2 inhibitor empagliflozin on NLRP3 inflammasome activity. Patients with T2D and high cardiovascular risk receive SGLT2 inhibitor or sulfonylurea for 30 days, with NLRP3 inflammasome activation analyzed in macrophages. While the SGLT2 inhibitor's glucose-lowering capacity is similar to sulfonylurea, it shows a greater reduction in IL-1β secretion compared to sulfonylurea accompanied by increased serum β-hydroxybutyrate (BHB) and decreased serum insulin. Ex vivo experiments with macrophages verify the inhibitory effects of high BHB and low insulin levels on NLRP3 inflammasome activation. In conclusion, SGLT2 inhibitor attenuates NLRP3 inflammasome activation, which might help to explain its cardioprotective effects.
Sarcopenia is associated with nonalcoholic fatty liver disease (NAFLD). This study investigated whether sarcopenia is associated with significant liver fibrosis in subjects with NAFLD. Data from the ...Korean National Health and Nutrition Examination Surveys 2008‐2011 database were analyzed. NALFD was defined by NAFLD liver fat score, comprehensive NAFLD score, or hepatic steatosis index. Degree of liver fibrosis was assessed by NAFLD fibrosis score (NFS), FIB‐4, and Forns index. Significant liver fibrosis was defined as FIB‐4 ≥2.67 and the highest quartile values of NFS and Forns index. Sarcopenia index (= total appendicular skeletal muscle mass kg/body mass index (kg/m2) was calculated using dual‐energy X‐ray absorptiometry. Using the NAFLD liver fat score, NAFLD was identified in 2761 (28.5%) of 9676 subjects. Of subjects with NAFLD, sarcopenia was identified in 337 (12.2%). Sarcopenia was significantly associated with significant liver fibrosis assessed in fibrosis prediction models (all P < 0.05). In subgroups stratified according to body mass index and homeostasis model assessment of insulin resistance, a significant association between sarcopenia and significant liver fibrosis by NFS was consistently present (odds ratio = 1.76‐2.68 depending on the subgroup, all P < 0.05). Multivariate logistic regression analysis demonstrated an independent association between SI and significant liver fibrosis by NFS after adjusting for other confounders (odds ratio = 0.52‐0.67, all P < 0.01). Other NAFLD (comprehensive NAFLD score, hepatic steatosis index) and fibrosis prediction models (FIB‐4 and Forns index) produced similar results. Conclusion: Sarcopenia is associated with significant liver fibrosis in subjects with NAFLD, and the association is independent of obesity and insulin resistance. (Hepatology 2016;63:776–786)
Metformin activates both PRKA and SIRT1. Furthermore, autophagy is induced by either the PRKA-MTOR-ULK1 or SIRT1-FOXO signaling pathways. We aimed to elucidate the mechanism by which metformin ...alleviates hepatosteatosis by examining the molecular interplay between SIRT1, PRKA, and autophagy. ob/ob mice were divided into 3 groups: one with ad libitum feeding of a standard chow diet, one with 300 mg/kg intraperitoneal metformin injections, and one with 3 g/d caloric restriction (CR) for a period of 4 wk. Primary hepatocytes or HepG2 cells were treated with oleic acid (OA) plus high glucose in the absence or presence of metformin. Both CR and metformin significantly improved body weight and glucose homeostasis, along with hepatic steatosis, in ob/ob mice. Furthermore, CR and metformin both upregulated SIRT1 expression and also stimulated autophagy induction and flux in vivo. Metformin also prevented OA with high glucose-induced suppression of both SIRT1 expression and SIRT1-dependent activation of autophagy machinery, thereby alleviating intracellular lipid accumulation in vitro. Interestingly, metformin treatment upregulated SIRT1 expression and activated PRKA even after siRNA-mediated knockdown of PRKAA1/2 and SIRT1, respectively. Taken together, these results suggest that metformin alleviates hepatic steatosis through PRKA-independent, SIRT1-mediated effects on the autophagy machinery.
Metabolic (dysfunction) associated fatty liver disease (MAFLD) is generally developed with excessive accumulation of lipids in the liver. Ketogenesis is an efficient pathway for the disposal of fatty ...acids in the liver and its metabolic benefits have been reported. In this review, we examined previous studies on the association between ketogenesis and MAFLD and reviewed the candidate mechanisms that can explain this association.
Non-alcoholic fatty liver disease (NAFLD) is a prevalent and rapidly increasing disease worldwide; however, no widely accepted screening models to assess the risk of NAFLD are available. Therefore, ...we aimed to develop and validate a self-assessment score for NAFLD in the general population using two independent cohorts.
The development cohort comprised 15676 subjects (8313 males and 7363 females) who visited the National Health Insurance Service Ilsan Hospital in Korea in 2008-2010. Anthropometric, clinical, and laboratory data were examined during regular health check-ups and fatty liver diagnosed by abdominal ultrasound. Logistic regression analysis was conducted to determine predictors of prevalent NAFLD and to derive risk scores/models. We validated our models and compared them with other existing methods using an external cohort (N = 66868).
The simple self-assessment score consists of age, sex, waist circumference, body mass index, history of diabetes and dyslipidemia, alcohol intake, physical activity and menopause status, which are independently associated with NAFLD, and has a value of 0-15. A cut-off point of ≥ 8 defined 58% of males and 36% of females as being at high-risk of NAFLD, and yielded a sensitivity of 80% in men (77% in women), a specificity of 67% (81%), a positive predictive value of 72% (63%), a negative predictive value of 76% (89%) and an AUC of 0.82 (0.88). Comparable results were obtained using the validation dataset. The comprehensive NAFLD score, which includes additional laboratory parameters, has enhanced discrimination ability, with an AUC of 0.86 for males and 0.91 for females. Both simple and comprehensive NAFLD scores were significantly increased in subjects with higher fatty liver grades or severity of liver conditions (e.g., simple steatosis, steatohepatitis).
The new non-laboratory-based self-assessment score may be useful for identifying individuals at high-risk of NAFLD. Further studies are warranted to evaluate the utility and feasibility of the scores in various settings.
Aim
To investigate the effectiveness and safety of teneligliptin over placebo in patients with type 2 diabetes (T2D) inadequately controlled by triple therapy.
Materials and Methods
This trial was a ...prospective, multicentre, randomized, double‐blind, placebo‐controlled study. The 12‐week double‐blind period was followed by a 12‐week, open‐label clinical trial. One hundred patients with T2D who failed to achieve the glycaemic target (7.1% ≤ HbA1c ≤ 9.0%) with conventional triple oral antidiabetic drugs (OADs) of metformin, sulphonylurea, and sodium‐glucose co‐transporter‐2 inhibitor were assigned randomly 1:1 into teneligliptin and placebo‐teneligliptin groups. The primary endpoint was mean change in HbA1c level from baseline in each group at 12 weeks.
Results
For a total of 99 patients (n = 51 for the teneligliptin group, and n = 48 for the placebo‐teneligliptin group), the mean age and duration of diabetes were 60.7 and 13.6 years, respectively, and HbA1c was 7.8% at baseline. At 12 weeks, the teneligliptin group achieved a significant reduction in HbA1c from baseline (−0.9% ± 0.6%, P < .001), with an intergroup difference of −0.75% compared with the placebo group (95% CI –0.99%, –0.51%, P < .001). At the end of the 24‐week treatment period, both groups showed significant reductions in HbA1c level from baseline (placebo‐teneligliptin group, –0.8% ± 0.6% P < .001, teneligliptin group, –0.9% ± 0.6% P < .001), without significant intergroup difference (−0.17%, 95% CI −0.41%, 0.07%, P = .156). There was no significant difference between the groups in the rate of adverse events (placebo‐teneligliptin group, n = 3 6.3%; teneligliptin group, n = 11 11.1%; P = .550), and the safety profiles were favourable in both groups.
Conclusions
The current study shows that teneligliptin could be a valid option as a fourth OAD for the treatment of patients with T2D inadequately controlled with a triple combination of OADs.
Impairment in macroautophagy/autophagy flux and inflammasome activation are common characteristics of nonalcoholic steatohepatitis (NASH). Considering the lack of approved agents for treating NASH, ...drugs that can enhance autophagy and modulate inflammasome pathways may be beneficial. Here, we investigated the novel mechanism of ezetimibe, a widely prescribed drug for hypercholesterolemia, as a therapeutic option for ameliorating NASH. Human liver samples with steatosis and NASH were analyzed. For in vitro studies of autophagy and inflammasomes, primary mouse hepatocytes, human hepatoma cells, mouse embryonic fibroblasts with Ampk or Tsc2 knockout, and human or primary mouse macrophages were treated with ezetimibe and palmitate. Steatohepatitis and fibrosis were induced by feeding Atg7 wild-type, haploinsufficient, and knockout mice a methionine- and choline-deficient diet with ezetimibe (10 mg/kg) for 4 wk. Human livers with steatosis or NASH presented impaired autophagy with decreased nuclear TFEB and increased SQSTM1, MAP1LC3-II, and NLRP3 expression. Ezetimibe increased autophagy flux and concomitantly ameliorated lipid accumulation and apoptosis in palmitate-exposed hepatocytes. Ezetimibe induced AMPK phosphorylation and subsequent TFEB nuclear translocation, related to MAPK/ERK. In macrophages, ezetimibe blocked the NLRP3 inflammasome-IL1B pathway in an autophagy-dependent manner and modulated hepatocyte-macrophage interaction via extracellular vesicles. Ezetimibe attenuated lipid accumulation, inflammation, and fibrosis in liver-specific Atg7 wild-type and haploinsufficient mice, but not in knockout mice. Ezetimibe ameliorates steatohepatitis by autophagy induction through AMPK activation and TFEB nuclear translocation, related to an independent MTOR ameliorative effect and the MAPK/ERK pathway. Ezetimibe dampens NLRP3 inflammasome activation in macrophages by modulating autophagy and a hepatocyte-driven exosome pathway.
Nonalcoholic fatty liver disease (NAFLD) and sarcopenia have a close association with an increased risk of atherosclerotic cardiovascular disease (ASCVD). This study investigated the influence of ...NAFLD and sarcopenia on ASCVD risk.
Data from the 2008-2011 Korean National Health and Nutrition Examination Surveys database were analyzed (n = 7,191). The sarcopenia index was calculated using dual-energy x-ray absorptiometry. Sarcopenia was defined as the lowest quintile sarcopenia index value (cutoffs = 0.882 for men and 0.582 for women). NAFLD was defined as a comprehensive NAFLD score ≥40. Liver fibrosis was assessed using the fibrosis-4 (FIB-4) index. ASCVD risk was evaluated using American College of Cardiology/American Heart Association guidelines. High probability of ASCVD was defined as ASCVD risk >10%.
The prevalence rates of NAFLD and sarcopenia were 31.2% (n = 2,241) and 19.5% (n = 1,400), respectively. The quartile-stratified ASCVD risk scores were positively associated with NAFLD and sarcopenia (all P for trend < 0.001). Subjects with both NAFLD and sarcopenia had a higher risk for high probability of ASCVD (odds ratio = 1.83, P = 0.014) compared with controls without NAFLD and sarcopenia. Among subjects with NAFLD, FIB-4-defined significant liver fibrosis and sarcopenia additively raised the risk for high probability of ASCVD (odds ratio = 3.56, P < 0.001) compared with controls without FIB-4-defined significant liver fibrosis or sarcopenia.
NAFLD and sarcopenia were significantly associated with an increased risk of ASCVD in the general population. In addition, NAFLD with significant liver fibrosis and sarcopenia were significantly associated with an increased risk of ASCVD in subjects with NAFLD.
Aim
To investigate sodium‐glucose cotransporter 2 inhibitor (SGLT2i)‐induced changes in ketogenic enzymes and transporters in normal and diabetic mice models.
Materials and methods
Normal mice were ...randomly assigned to receive either vehicle or SGLT2i (25 mg/kg/d by oral gavage) for 7 days. Diabetic mice were treated with vehicle, insulin (4.5 units/kg/d by subcutaneous injection) or SGLT2i (25 mg/kg/d by intra‐peritoneal injection) for 5 weeks. Serum and tissues of ketogenic organs were analysed.
Results
In both normal and diabetic mice, SGLT2i increased beta‐hydroxybutyrate (BHB) content in liver, kidney and colon tissue, as well as in serum and urine. In these organs, SGLT2i upregulated mRNA expression of ketogenic enzymes, 3‐hydroxy‐3‐methylglutaryl‐coenzyme A synthase 2 and 3‐hydroxy‐3‐methylglutaryl‐coenzyme A lyase. Similar patterns were observed in the kidney, ileum and colon for mRNA and protein expression of sodium‐dependent monocarboxylate transporters (SMCTs), which mediate the cellular uptake of BHB and butyrate, an important substrate for intestinal ketogenesis. In diabetic mice under euglycaemic conditions, SGLT2i increased major ketogenic enzymes and SMCTs, while insulin suppressed ketogenesis.
Conclusions
SGLT2i increased systemic and tissue BHB levels by upregulating ketogenic enzymes and transporters in the liver, kidney and intestine, suggesting the integrated physiological consequences for ketone body metabolism of SGLT2i administration.
Metabolic-associated fatty liver disease (MAFLD) and diabetic kidney disease (DKD) share various pathophysiological factors, and epidemiological evidence suggests that these two diseases are ...associated. Albuminuria and the estimated glomerular filtration rate, which are conventional biomarkers of DKD, are reportedly associated with the risk or severity of MAFLD. Recently, novel DKD biomarkers reflecting renal tubular injury have been introduced to complement conventional DKD markers. In this article, we looked at previous studies that showed an association between MAFLD and DKD, and also reviewed the significance of DKD biomarkers as predictive risk factors for MAFLD.
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