Ablation of secreted phosphoprotein-1 in hepatocytes increases fatty acid oxidation and ameliorates alcohol-associated liver disease.

BACKGROUND: Previously, we demonstrated that Spp1-/- mice exhibit a greater susceptibility to alcohol-induced liver injury than wild-type (WT) mice. Notably, alcohol triggers the expression of osteopontin (encoded by SPP1) in hepatocytes. However, the specific role of hepatocyte-derived SPP1 in either mitigating or exacerbating alcohol-associated liver disease (AALD) has yet to be elucidated. We hypothesized that hepatocyte-derived SPP1 plays a role in AALD by modulating the regulation of steatosis. METHODS: We analyzed hepatic SPP1 expression using four publicly available datasets from patients with alcoholic hepatitis (AH). Additionally, we examined SPP1 expression in the livers of WT mice subjected to either a control or ethanol Lieber-DeCarli (LDC) diet for 6 weeks. We compared the relationship between SPP1 expression and significantly dysregulated genes in AH with controls using correlation and enrichment analyses. To investigate the specific impact of hepatocyte-derived SPP1, we generated hepatocyte-specific Spp1 knock-out (Spp1ΔHep) mice and subjected them to either a control or ethanol Lieber-DeCarli diet for 6 weeks. RESULTS: Alcohol induced hepatic SPP1 expression in both humans and mice. Our analysis, focusing on genes correlated with SPP1, revealed an enrichment of fatty acid oxidation (FAO) in three datasets, and peroxisome proliferator-activated receptor signaling in one dataset. Notably, FAO genes correlating with SPP1 were downregulated in patients with AH. Ethanol-fed WT mice exhibited higher serum-free fatty acids (FFAs), adipose tissue lipolysis, and hepatic fatty acid (FA) transporters. In contrast, ethanol-fed Spp1ΔHep mice displayed lower liver triglycerides, FFAs, and serum alanine transaminase and greater FAO gene expression than WT mice, indicating a protective effect against AALD. Primary hepatocytes from Spp1∆Hep mice exhibited heightened expression of genes encoding proteins involved in FAO. CONCLUSIONS: Alcohol induces the expression of SPP1 in hepatocytes, leading to impaired FAO and contributing to the development of AALD.

Augmenter of liver regeneration: Mitochondrial function and steatohepatitis.

Augmenter of liver regeneration (ALR), a ubiquitous fundamental life protein, is expressed more abundantly in the liver than other organs. Expression of ALR is highest in hepatocytes, which also constitutively secrete it. ALR gene transcription is regulated by NRF2, FOXA2, SP1, HNF4α, EGR-1 and AP1/AP4. ALR's FAD-linked sulfhydryl oxidase activity is essential for protein folding in the mitochondrial intermembrane space. ALR's functions also include cytochrome c reductase and protein Fe/S maturation activities. ALR depletion from hepatocytes leads to increased oxidative stress, impaired ATP synthesis and apoptosis/necrosis. Loss of ALR's functions due to homozygous mutation causes severe mitochondrial defects and congenital progressive multiorgan failure, suggesting that individuals with one functional ALR allele might be susceptible to disorders involving compromised mitochondrial function. Genetic ablation of ALR from hepatocytes induces structural and functional mitochondrial abnormalities, dysregulation of lipid homeostasis and development of steatohepatitis. High-fat diet-fed ALR-deficient mice develop non-alcoholic steatohepatitis (NASH) and fibrosis, while hepatic and serum levels of ALR are lower than normal in human NASH and NASH-cirrhosis. Thus, ALR deficiency may be a critical predisposing factor in the pathogenesis and progression of NASH.

Unveiling anticancer potential of glibenclamide: Its synergistic cytotoxicity with doxorubicin on cancer cells.

Drug repurposing has been an emerging therapeutic strategy, which involves exploration of a new therapeutic approach for the use of an existing drug. Glibenclamide (Gli) is an anti-diabetic sulfonylurea drug extensively used for the treatment of type-2 diabetes, it has also been shown to possess anti-proliferative effect against several types of tumors. The present study was executed to understand the mechanisms underlying the interaction of Gli with DNA under physiological conditions. The binding mechanism of Gli with DNA was scrutinized by UV-vis absorption spectroscopy and fluorescence emission spectroscopy. The conformational changes and electrochemical properties were analyzed by circular dichroism spectroscopy and cyclic voltammetry. Isothermal titration calorimetry was employed to examine the thermodynamic changes and molecular docking technique used to analyze the interaction mode of Gli with DNA. The spectroscopic studies revealed that Gli interacts with DNA through groove binding mode. Further, isothermal titration calorimetry depicted a stronger mode of interaction favorably groove-binding. Recently, systemic combination therapy has shown significant promise in inhibiting multiple targets simultaneously yielding high therapeutic competence with lesser side effects. With this concern, we intended to study the combined cytotoxicity of Gli with doxorubicin (Dox). The results of MTT assay and acridine orange (AO)/ethidium bromide (EtBr) staining showed synergistic cytotoxicity of Gli + Dox combination on HepG2 & A549 cells. The present study documents the intricate mechanism of Gli-DNA interaction and delivers a multifaceted access for chemotherapy by Gli + Dox combination.