Innovative Therapeutic Approaches in Non-Alcoholic Fatty Liver Disease: When Knowing Your Patient Is Key

Metabolic dysfunction-associated steatotic liver disease (MASLD): Exploring systemic impacts and innovative therapies

Metabolic dysfunction-associated steatotic liver disease (MASLD), which includes the inflammatory subtype metabolic dysfunction-associated steatohepatitis, is a prominent cause of chronic liver disease with systemic effects. Insulin resistance, obesity, and dyslipidaemia produce MASLD in over 30 % of adults. It is a global health issue. From MASLD to MASH, hepatic inflammation and fibrosis grow, leading to cirrhosis, hepatocellular cancer, and extrahepatic complications such CVD, CKD, and sarcopenia. Effects of MASLD to MASH are mediated through mechanisms that include inflammation, oxidative stress, dysbiosis, and predisposition through genetic makeup. Advances in diagnostic nomenclature in the past few years have moved the emphasis away from NAFLD to MASLD, focusing on the metabolic etiology and away from the stigma of an alcoholic-related condition. Epidemiological data show a large geographical variability and increasing prevalence in younger populations, particularly in regions with high carbohydrate-rich diets and central adiposity. Lifestyle modification is considered as the main management of MASLD currently. This may include dietary intervention, exercise, and weight loss management. Pharmaceutical management is primarily aimed at metabolic dysfunction with promising findings for GLP-1 receptor agonists, pioglitazone and SGLT-2 inhibitors, which can correct both hepatic and systemic outcome. However, it still depends on well-integrated multidisciplinary care models by considering complex relationships between MASLD and its effects on extrahepatic organs. Determining complications at an early stage; developing precision medicine strategies; exploring new therapeutic targets will represent crucial factors in improving their outcomes. This review discuss the systemic nature of MASLD and calls for multiple collaborations to reduce its far-reaching health impacts and our quest for understanding its pathological mechanisms. Thus, collective efforts that are required to address MASLD are under the public health, clinical care, and research angles toward effectively containing its rapidly increasing burden.

Redox regulation: mechanisms, biology and therapeutic targets in diseases

Redox signaling acts as a critical mediator in the dynamic interactions between organisms and their external environment, profoundly influencing both the onset and progression of various diseases. Under physiological conditions, oxidative free radicals generated by the mitochondrial oxidative respiratory chain, endoplasmic reticulum, and NADPH oxidases can be effectively neutralized by NRF2-mediated antioxidant responses. These responses elevate the synthesis of superoxide dismutase (SOD), catalase, as well as key molecules like nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH), thereby maintaining cellular redox homeostasis. Disruption of this finely tuned equilibrium is closely linked to the pathogenesis of a wide range of diseases. Recent advances have broadened our understanding of the molecular mechanisms underpinning this dysregulation, highlighting the pivotal roles of genomic instability, epigenetic modifications, protein degradation, and metabolic reprogramming. These findings provide a foundation for exploring redox regulation as a mechanistic basis for improving therapeutic strategies. While antioxidant-based therapies have shown early promise in conditions where oxidative stress plays a primary pathological role, their efficacy in diseases characterized by complex, multifactorial etiologies remains controversial. A deeper, context-specific understanding of redox signaling, particularly the roles of redox-sensitive proteins, is critical for designing targeted therapies aimed at re-establishing redox balance. Emerging small molecule inhibitors that target specific cysteine residues in redox-sensitive proteins have demonstrated promising preclinical outcomes, setting the stage for forthcoming clinical trials. In this review, we summarize our current understanding of the intricate relationship between oxidative stress and disease pathogenesis and also discuss how these insights can be leveraged to optimize therapeutic strategies in clinical practice.

Efect of N-acetylcysteine on HepG2 cells which were induced into fatty liver cells

Non-alcoholic fatty liver disease is a prevalent liver condition that can progress to fibrosis and cirrhosis. It also poses a risk for hepatocellular carcinoma, underscoring the importance of identifying effective treatments. N-acetylcysteine, an inhibitor of glutathione depletion, shows promise in modulating intracellular glutathione biosynthesis and combating oxidative stress, making it a potentially beneficial therapy for liver fibrosis in non-alcoholic fatty liver disease. This study assesses the impact of N-acetylcysteine on HepG2 cells which were induced into fatty liver cells was evaluated. HepG2 cells were cultured in DMEM and seeded onto six-well plates at a density of 5 × 105 cells. Following a 24-h incubation period, the cells were exposed to a medium inducing fat accumulation. Subsequently, the cells were treated with varying concentrations of N-acetylcysteine for 48 h. Some plates were utilized for Real-Time-PCR tests, while others underwent Oil Red staining. The findings indicated a significant increase in the expression of fatty acid β-oxidation genes in the group treated with 10mM N-acetylcysteine (p < 0.05), along with reduced expression of lipogenesis-related genes (p < 0.05) in N-acetylcysteine-treated groups. Analysis of apoptotic gene expression revealed decreased BAX expression but increased BCL2 expression in the N-acetylcysteine-treated groups. Oil Red staining demonstrated a dose-dependent reduction in lipid droplets compared to the control group. This study's results suggest that N-acetylcysteine has the potential to decrease lipid droplets and modulate lipid metabolism effectively.

Systemic impacts of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) on heart, muscle, and kidney related diseases

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease (NAFLD), is the most common liver disorder worldwide, with an estimated global prevalence of more than 31%. Metabolic dysfunction-associated steatohepatitis (MASH), formerly known as non-alcoholic steatohepatitis (NASH), is a progressive form of MASLD characterized by hepatic steatosis, inflammation, and fibrosis. This review aims to provide a comprehensive analysis of the extrahepatic manifestations of MASH, focusing on chronic diseases related to the cardiovascular, muscular, and renal systems. A systematic review of published studies and literature was conducted to summarize the findings related to the systemic impacts of MASLD and MASH. The review focused on the association of MASLD and MASH with metabolic comorbidities, cardiovascular mortality, sarcopenia, and chronic kidney disease. Mechanistic insights into the concept of lipotoxic inflammatory "spill over" from the MASH-affected liver were also explored. MASLD and MASH are highly associated (50%-80%) with other metabolic comorbidities such as impaired insulin response, type 2 diabetes, dyslipidemia, hypertriglyceridemia, and hypertension. Furthermore, more than 90% of obese patients with type 2 diabetes have MASH. Data suggest that in middle-aged individuals (especially those aged 45-54), MASLD is an independent risk factor for cardiovascular mortality, sarcopenia, and chronic kidney disease. The concept of lipotoxic inflammatory "spill over" from the MASH-affected liver plays a crucial role in mediating the systemic pathological effects observed. Understanding the multifaceted impact of MASH on the heart, muscle, and kidney is crucial for early detection and risk stratification. This knowledge is also timely for implementing comprehensive disease management strategies addressing multi-organ involvement in MASH pathogenesis.

MAFLD Pandemic: Updates in Pharmacotherapeutic Approach Development

With around one billion of the world's population affected, the era of the metabolic-associated fatty liver disease (MAFLD) pandemic has entered the global stage. MAFLD is a chronic progressive liver disease with accompanying metabolic disorders such as type 2 diabetes mellitus and obesity which can progress asymptomatically to liver cirrhosis and subsequently to hepatocellular carcinoma (HCC), and for which to date there are almost no approved pharmacologic options. Because MAFLD has a very complex etiology and it also affects extrahepatic organs, a multidisciplinary approach is required when it comes to finding an effective and safe active substance for MAFLD treatment. The optimal drug for MAFLD should diminish steatosis, fibrosis and inflammation in the liver, and the winner for MAFLD drug authorisation seems to be the one that significantly improves liver histology. Saroglitazar (Lipaglyn®) was approved for metabolic-dysfunction-associated steatohepatitis (MASH) in India in 2020; however, the drug is still being investigated in other countries. Although the pharmaceutical industry is still lagging behind in developing an approved pharmacologic therapy for MAFLD, research has recently intensified and many molecules which are in the final stages of clinical trials are expected to be approved in the coming few years. Already this year, the first drug (Rezdiffra™) in the United States was approved via accelerated procedure for treatment of MAFLD, i.e., of MASH in adults. This review underscores the most recent information related to the development of drugs for MAFLD treatment, focusing on the molecules that have come furthest towards approval.

Diet-Induced Gut Dysbiosis and Leaky Gut Syndrome

Chronic gut inflammation promotes the development of metabolic diseases such as obesity. There is growing evidence which suggests that dysbiosis in gut microbiota and metabolites disrupt the integrity of the intestinal barrier and significantly impact the level of inflammation in various tissues, including the liver and adipose tissues. Moreover, dietary sources are connected to the development of leaky gut syndrome through their interaction with the gut microbiota. This review examines the effects of these factors on intestinal microorganisms and the communication pathways between the gut-liver and gut-brain axis. The consumption of diets rich in fats and carbohydrates has been found to weaken the adherence of tight junction proteins in the gastrointestinal tract. Consequently, this allows endotoxins, such as lipopolysaccharides produced by detrimental bacteria, to permeate through portal veins, leading to metabolic endotoxemia and alterations in the gut microbiome composition with reduced production of metabolites, such as short-chain fatty acids. However, the precise correlation between gut microbiota and alternative sweeteners remains uncertain, necessitating further investigation. This study highlights the significance of exploring the impact of diet on gut microbiota and the underlying mechanisms in the gut-liver and gut-brain axis. Nevertheless, limited research on the gut-liver axis poses challenges in comprehending the intricate connections between diet and the gut-brain axis. This underscores the need for comprehensive studies to elucidate the intricate gut-brain mechanisms underlying intestinal health and microbiota.

Analysis of gene expression changes during lipid droplet formation in HepG2 human liver cancer cells

Fatty liver is a condition of excessive triglyceride accumulation in hepatocytes. Additionally, hepatocytes exhibit a high degree of fat droplet accumulation during excessive alcohol consumption and metabolic syndrome. However, the molecular mechanisms involved in fat droplet formation remain unknown. The present study used an in vitro fatty liver formation model of the human liver cancer cell line, HepG2, to comprehensively search for fat droplet formation-related genes, and which exhibit changes in expression during fat droplet formation. Microarray analysis with extracted total RNA determined the genes that are involved in fat droplet formation and their expression was confirmed using quantitative polymerase chain reaction following the culture of the HepG2 cells in culture medium containing 0, 50, 200 and 500 µM of oleic acid for 24 h. The results revealed 142 genes demonstrating increased expression levels by >2.0-fold with oleic acid treatment and 426 genes demonstrating decreased expression levels. Perilipin 2 (PLIN2) was estimated as the gene most closely associated with fatty liver. Lipid droplet formation in the HepG2 cells induced by oleic acid led to the upregulation of PLIN2 in a concentration-dependent manner. On the whole, the findings of the present study indicate the involvement of genes in oleic acid-induced lipid droplet formation in HepG2 cells; PLIN2 in particular may play a crucial role in this process.