Dapagliflozin protects against nonalcoholic steatohepatitis in db/db mice

Bioinformatics analysis combined with experimental validation reveals the novel mechanisms of multi-targets of dapagliflozin attenuating diabetic liver injury

Objective

Diabetic liver injury, a chronic complication of diabetes mellitus (DM), has been extensively documented. Dapagliflozin, a sodium-glucose co-transporter 2 (SGLT2) inhibitor, has shown significant therapeutic benefits in clinical trials for the management of diabetes However, the specific mechanism on the treatment of diabetic liver injury with dapagliflozin is not fully understood. Therefore, this study aims to further explore the potential mechanism of dapagliflozin on diabetic liver injury based on bioinformatics analysis and experimental verification.

Methods

Diabetic liver injury was induced by a high-fat diet combined with STZ in mice. Biochemical kit detection and H&E staining were used to observe lipid aggregation and oxidative stress in liver tissue. Moreover, the expression of inflammatory and apoptosis-related factors was detected using western blotting (WB) and quantitative polymerase chain reaction (qPCR). Subsequently, differential expressions genes analysis, weighted gene co-expression network analysis (WGCNA), molecular docking, as well as molecular dynamics was conducted based on the Gene Expression Omnibus (GEO) and pharmacology databases. Finally, WB and qPCR were performed to validate the mechanism of dapagliflozin on diabetic liver injury in vivo and in vitro.

Results

Dapagliflozin alleviated diabetic liver injury by decreasing lipid deposition, oxidative stress levels, the inflammatary and apoptosis-related proteins and mRNA levels, while it also reducing blood glucose. Mechanically, 78 overlapping genes of dapagliflozin and diabetic liver injury were obtained. Notably, Mapk3, Mapk1, Ikbkb, and Nfkb1 as the hub genes involved in dapagliflozin attenuating diabetic liver injury were identified, and dapagliflozin exhibited better affinity with these proteins. Moreover, dapagliflozin inhibited the elevated protein (genes) levels of ERK1/2 (Mapk3, Mapk1), IKKβ(Ikbkb), and NF-κB (Nfkb1), which are induced by diabetic liver injury, as confirmed by both in vivo and in vitro experiments.

Conclusion

Dapagliflozin ameliorated diabetic liver injury by inhibiting the ERK/IKKβ/NF-κB signalling pathway, as demonstrated by bioinformatics analysis combined with in vivo and in vitro experiments.

Therapeutic Potential of Sotagliflozin in Animal Models of Non-alcoholic Fatty Liver Disease with and without Diabetes

Sotagliflozin, a dual SGLT1/2 inhibitor, enhances glucagon like peptide-1 (GLP-1) levels and GLP-1 receptor agonists are used to manage non-alcoholic fatty liver disease (NAFLD). Study investigates the effects of sotagliflozin on NAFLD, alone and combined with linagliptin, comparing outcomes in normoglycemic and hyperglycemic animal models.Obese fatty liver disease (FLD) model was induced by high-fat diet (HFD) feeding, while a diabetic non-alcoholic steatohepatitis (NASH) model was developed by administering a single dose of streptozotocin to neonatal mice, followed by HFD feeding post-weaning. At termination of the study, parameters including biochemical markers, inflammatory cytokines, hepatic lipid content, and histopathology were assessed.In NASH mice, sotagliflozin and linagliptin reduced hepatic triglycerides by 60% and 44%, respectively, and cholesterol by 46% and 49%. Their combination further decreased triglycerides by 68.5% and cholesterol by 83.9%. In FLD mice, sotagliflozin and linagliptin reduced triglycerides by 33% and 17%, respectively, and cholesterol by 46% and 21%. Combination treatment offered no benefit, reducing triglycerides by 38% and cholesterol by 27%. Both the treatments improved plasma fibroblast growth factor 21, hepatic interlukin-6, glucose tolerance, steatosis and mitigated fat pad weight, but their combination did not show additional benefit. However, combination treatment demonstrated added benefit in modulating NAFLD activity score, liver enzymes, glycogenated hepatic nuclei, plasma glucose and active GLP-1 levels.Study underscores sotagliflozin's potential to mitigate NAFLD and highlights the benefit of combining it with linagliptin in hyperglycemic NASH model, which showed limited efficacy in normoglycemic FLD mice.

Efficacy and safety of dapagliflozin compared to pioglitazone in diabetic and non-diabetic patients with non-alcoholic steatohepatitis: A randomized clinical trial

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is a serious end-stage spectrum of non-alcoholic fatty liver disease (NAFLD) with associated high risk of hepatic and extrahepatic complications. Several studies showed the significant beneficial effect of dapagliflozin on body composition, hepatic and metabolic parameters on NAFLD/NASH patients. The study aimed to investigate the efficacy and safety of dapagliflozin in both diabetic and non-diabetic biopsy-proven NASH patients; compared to pioglitazone.

METHODS

This was a four-group, prospective, randomized, parallel, open label study in which 100 biopsy-proven NASH patients were selected, stratified to diabetics and non-diabetics and randomized with 1:1 allocation to either 30 mg pioglitazone or 10 mg dapagliflozin, once daily for 24 weeks. Histological evaluation, anthropometric measures, hepatic, metabolic biochemical markers, fibrosis non-invasive markers, quality of life (QOL) and medications adverse events were examined.

RESULTS

Dapagliflozin showed a comparable histological effect to pioglitazone in both diabetic and non-diabetic patients (P>0.05). As assessed by transient elastography, it also showed a comparable effect on liver fibrosis grade improvement from baseline in diabetics (P=0.287) versus a significant superiority in non-diabetics (P=0.018). Dapagliflozin showed a significant superiority in all anthropometric measures (P<0.001) and QOL (P<0.05) among both diabetics and non-diabetics. There was a significant interaction between interventions and diabetes status on change from baseline of hepatic and metabolic panel collectively (P=0.023) in favor to dapagliflozin among diabetics.

CONCLUSION

Compared to pioglitazone, dapagliflozin had a comparable effect histologically, superior effect biochemically among diabetics and superior effect on liver fibrosis, steatosis and insulin resistance among non-diabetics.

TRIAL REGISTRATION

The study was registered on clinicaltrials.gov, identifier number NCT05254626.

SGLT2i and GLP1-RA exert additive cardiorenal protection with a RAS blocker in uninephrectomized db/db mice

Introduction

Diabetic Kidney Disease (DKD) is the main cause of end-stage renal disease in the developed world. The current treatment of the DKD with renin-angiotensin system (RAS) blockade does not totally halt the progression to end stage kidney disease. Currently, several drugs have shown to delay DKD progression such as sodium-glucose co-transporter-2 inhibitors (SGLT2i) and glucagon-like-1 receptor agonists (GLP-1RA). We hypothesized that by combining several drugs that prevent DKD progression on top of RAS blockade a synergistic effect would be achieved in terms of cardiorenal protection. In the present study, we analysed if the combination of a RAS blocker (ramipril) with a SGLT2i (empagliflozin) and/or GLP-1RA (semaglutide) in a type 2 diabetic mouse model could have add-on effects in kidney and heart protection.

Methods

Male and female uninephrectomized type 2 diabetic db/db mice were treated with empagliflozin and/or semaglutide on top of ramipril during 8 weeks. During the study body weight, water and food intake were weekly monitored, glycaemia biweekly and albuminuria and glomerular filtration rate (GFR) before and after the treatment. At the end of the experiment, kidney and heart were isolated for histological and gene expression studies as well as for intrarenal RAS state assessment.

Results

Semaglutide combined with ramipril and/or empagliflozin significantly decreased albuminuria but only when combined with both compounds, semaglutide further decreased blood glucose, glomerular hyperfiltration in male mice and glomerular mesangial matrix expansion. In kidney, only the triple treatment with empagliflozin, semaglutide and ramipril reduced the expression of the proinflammatory and profibrotic genes ccl2 and TGFß1. In addition, the combination of empagliflozin and semaglutide on top of RAS blockade was superior in decreasing cardiomyocyte hypertrophy and heart fibrosis in db/db mice.

Discussion

Our results suggest that the combination of SGLT2i with GLP-1RA is superior in cardiorenal protection in DKD than the drugs administered alone on top of RAS blockade.

Research advances in the anti-inflammatory effects of SGLT inhibitors in type 2 diabetes mellitus

Diabetes mellitus is one of the most significant global burden diseases. It is well established that a chronic, systemic, low-grade inflammatory condition is strongly correlated with type 2 diabetes mellitus (T2D) and the development of target-organ damage (TOD). Sodium-glucose cotransporter inhibitors (SGLTis), novel oral drugs for the treatment of diabetes, act mainly by reducing glucose reabsorption in proximal renal tubules and/or the intestine. Several high-quality clinical trials and large observational studies have revealed that SGLTis significantly improve cardiovascular and renal outcomes in T2D patients. Increasing evidence suggests that this is closely related to their anti-inflammatory properties, which are mainly manifested by a reduction in plasma concentrations of inflammatory biomarkers. This review analyses the potential mechanisms behind the anti-inflammatory effects of SGLTis in diabetes and presents recent evidence of their therapeutic efficacy in treating diabetes and related TOD.

Dapagliflozin ameliorates hepatic steatosis via suppressing LXRα-mediated synthesis of lipids and bile acids

Nonalcoholic fatty liver disease (NAFLD) prevalence is rising globally with no pharmacotherapies approved. Hepatic steatosis is closely associated with progression and prognosis of NAFLD. Dapagliflozin, kind of sodium-glucose cotransporter 2 (SGLT2) inhibitor, was found to improve NAFLD in clinical trials, while the underlying mechanism remains poorly elucidated. Here, we reported that dapagliflozin effectively mitigated liver injury and relieved lipid metabolism disorders in vivo. Further investigation showed that dapagliflozin markedly suppressed Liver X Receptor α (LXRα)-mediated synthesis of de novo lipids and bile acids (BAs). In AML12 cells, our results proved dapagliflozin decreased lipid contents via inhibiting the expression of LXRα and downstream liposynthesis genes. Proteosome inhibitor MG132 eliminated the effect of dapagliflozin on LXRα-mediated signaling pathway, which suggested that dapagliflozin downregulated LXRα expression through increasing LXRα degradation. Knockdown of LXRα with siRNA abolished the reduction of lipogenesis from dapagliflozin treatment, indicating that LXRα might be the pivotal target for dapagliflozin to exhibit the aforementioned benefits. Furthermore, the data showed that dapagliflozin reversed gut dysbiosis induced by BAs disruption and altered gut microbiota profile to reduce intestinal lipids absorption. Together, our study deciphered a novel mechanism by which dapagliflozin relieved hepatic steatosis and highlighted the potential benefit of dapagliflozin in treating NAFLD.

Dapagliflozin alleviates arsenic trioxide-induced hepatic injury in rats via modulating PI3K/AkT/mTOR, STAT3/SOCS3/p53/MDM2 signaling pathways and miRNA-21, miRNA-122 expression

Dapagliflozin (DPG) is a sodium-glucose co-transporter 2 inhibitor that is commonly used in the treatment of type 2 diabetes. However, studies have shown that DPG has a protective effect under a variety of experimental conditions through its antioxidative and anti-inflammatory properties. DPG's effect on experimental hepatotoxicity caused by arsenic trioxide (ATO) has yet to be investigated. The purpose of this study was to investigate the protective effect of DPG in preventing hepatic damage caused by ATO and discover the underlying mechanisms. The effect of DPG (1 mg/kg, orally) on ATO (5 mg/kg, i.p.)-induced hepatic injury was evaluated in rats. Serum liver function parameters, as well as oxidative stress biomarkers and inflammatory cytokine levels were assessed. Histopathological changes in the liver were detected using H&E staining. Using Western blotting and PCR techniques, the molecular mechanisms of DPG in ameliorating hepatic injury were investigated. DPG improved liver function by inhibiting histopathological changes, decreasing levels of hepatic function and toxicity parameters measured in both serum and tissues, and exhibiting antioxidant and anti-inflammatory effects, according to the findings. Consistent with the PCR results, DPG also decreased the expression of LC3-II, micro-RNA-122, and micro-RNA-21 while increased the expression of SOCS3. Furthermore, according to western blotting results, DPG was able to reduce the protein expression of AKT, mTOR, PI3K, and STAT3. Although further clinical research is necessary, this study highlights the potential of DPG in preventing liver damage in a rat model of hepatotoxicity induced by ATO.

Liver fat as risk factor of hepatic and cardiometabolic diseases

Non-alcoholic fatty liver disease (NAFLD) is a disorder characterized by excessive accumulation of fat in the liver that can progress to liver inflammation (non-alcoholic steatohepatitis [NASH]), liver fibrosis, and cirrhosis. Although most efforts for drug development are focusing on the treatment of the latest stages of NAFLD, where significant fibrosis and NASH are present, findings from studies suggest that the amount of liver fat may be an important independent risk factor and/or predictor of development and progression of NAFLD and metabolic diseases. In this review, we first describe the current tools available for quantification of liver fat in humans and then present the clinical and pathophysiological evidence that link liver fat with NAFLD progression as well as with cardiometabolic diseases. Finally, we discuss current pharmacological and non-pharmacological approaches to reduce liver fat and present open questions that have to be addressed in future studies.

Antioxidant and anti-inflammatory agents in chronic liver diseases: Molecular mechanisms and therapy

Chronic liver disease (CLD) is a continuous process that causes a reduction of liver function lasting more than six months. CLD includes alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), chronic viral infection, and autoimmune hepatitis, which can lead to liver fibrosis, cirrhosis, and cancer. Liver inflammation and oxidative stress are commonly associated with the development and progression of CLD. Molecular signaling pathways such as AMP-activated protein kinase (AMPK), C-Jun N-terminal kinase, and peroxisome proliferator-activated receptors (PPARs) are implicated in the pathogenesis of CLD. Therefore, antioxidant and anti-inflammatory agents from natural products are new potent therapies for ALD, NAFLD, and hepatocellular carcinoma (HCC). In this review, we summarize some powerful products that can be potential applied in all the stages of CLD, from ALD/NAFLD to HCC. The selected agents such as β-sitosterol, curcumin, genistein, and silymarin can regulate the activation of several important molecules, including AMPK, Farnesoid X receptor, nuclear factor erythroid 2-related factor-2, PPARs, phosphatidylinositol-3-kinase, and lysyl oxidase-like proteins. In addition, clinical trials are undergoing to evaluate their efficacy and safety.

Recent Advances in the Digestive, Metabolic and Therapeutic Effects of Farnesoid X Receptor and Fibroblast Growth Factor 19: From Cholesterol to Bile Acid Signaling

Bile acids (BA) are amphiphilic molecules synthesized in the liver (primary BA) starting from cholesterol. In the small intestine, BA act as strong detergents for emulsification, solubilization and absorption of dietary fat, cholesterol, and lipid-soluble vitamins. Primary BA escaping the active ileal re-absorption undergo the microbiota-dependent biotransformation to secondary BA in the colon, and passive diffusion into the portal vein towards the liver. BA also act as signaling molecules able to play a systemic role in a variety of metabolic functions, mainly through the activation of nuclear and membrane-associated receptors in the intestine, gallbladder, and liver. BA homeostasis is tightly controlled by a complex interplay with the nuclear receptor farnesoid X receptor (FXR), the enterokine hormone fibroblast growth factor 15 (FGF15) or the human ortholog FGF19 (FGF19). Circulating FGF19 to the FGFR4/β-Klotho receptor causes smooth muscle relaxation and refilling of the gallbladder. In the liver the binding activates the FXR-small heterodimer partner (SHP) pathway. This step suppresses the unnecessary BA synthesis and promotes the continuous enterohepatic circulation of BAs. Besides BA homeostasis, the BA-FXR-FGF19 axis governs several metabolic processes, hepatic protein, and glycogen synthesis, without inducing lipogenesis. These pathways can be disrupted in cholestasis, nonalcoholic fatty liver disease, and hepatocellular carcinoma. Thus, targeting FXR activity can represent a novel therapeutic approach for the prevention and the treatment of liver and metabolic diseases.