Innate immunity and nonalcoholic fatty liver disease

Role of the type 3 cytokines IL-17 and IL-22 in modulating metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) comprises a spectrum of liver diseases that span simple steatosis, metabolic dysfunction-associated steatohepatitis (MASH) and fibrosis and may progress to cirrhosis and cancer. The pathogenesis of MASLD is multifactorial and is driven by environmental, genetic, metabolic and immune factors. This review will focus on the role of the type 3 cytokines IL-17 and IL-22 in MASLD pathogenesis and progression. IL-17 and IL-22 are produced by similar adaptive and innate immune cells such as Th17 and innate lymphoid cells, respectively. IL-17-related signaling is upregulated during MASLD resulting in increased chemokines and proinflammatory cytokines in the liver microenvironment, enhanced recruitment of myeloid cells and T cells leading to exacerbation of inflammation and liver disease progression. IL-17 may also act directly by activating hepatic stellate cells resulting in increased fibrosis. In contrast, IL-22 is a pleiotropic cytokine with a dominantly protective signature in MASLD and is currently being tested as a therapeutic strategy. IL-22 also exhibits beneficial metabolic effects and abrogates MASH-related inflammation and fibrosis development via inducing the production of anti-oxidants and anti-apoptotic factors. A sex-dependent effect has been attributed to both cytokines, most importantly to IL-22 in MASLD or related conditions. Altogether, IL-17 and IL-22 are key effectors in MASLD pathogenesis and progression. We will review the role of these two cytokines and cells that produce them in the development of MASLD, their interaction with host factors driving MASLD including sexual dimorphism, and their potential therapeutic benefits.

Effect of metabolic dysfunction‑associated fatty liver disease on the risk of hepatocellular carcinoma in patients with chronic hepatitis B: A systematic review and meta‑analysis

Hepatocellular carcinoma (HCC) remains an important complication in patients with chronic hepatitis B (CHB). An association between the presence of metabolic dysfunction-associated fatty liver disease (MAFLD) and an increased HCC risk in patients with CHB may exist; however, the exact nature of this possible association remains unclear. The present study conducted a comprehensive meta-analysis by pooling data from 18 studies encompassing 23,927 participants. The odds ratios (ORs) were calculated using a random-effects inverse-variance model, and heterogeneity was assessed using Cochran's Q test and the I² statistic. In addition, subgroup analyses were performed on the basis of geographical region, study design and follow-up length. Publication bias and meta-regression were also assessed. The overall pooled OR for the association between MAFLD and HCC risk in patients with CHB was 1.053 (95% CI, 0.704-1.576), which suggested a lack of association. Heterogeneity was observed across studies. Subgroup analyses demonstrated a potentially protective effect for MAFLD on the risk of HCC in patients in Asian countries (OR, 0.783; 95% CI, 0.568-1.080) and the opposite effect in other regions (OR, 4.380; 95% CI, 2.440-7.864). Analysis of the prospective cohort studies suggested a significant protective effect for MAFLD (OR, 0.479; 95% CI, 0.365-0.629), while analysis of retrospective cohorts did not. The publication bias assessment was inconclusive and the meta-regression failed to identify heterogeneity sources. The association between MAFLD and HCC risk in patients with CHB appeared to be multifactorial and may vary on the basis of geographical region and study design. While the exact mechanisms remain elusive, the potential protective effect demonstrated in certain subgroups warrants further investigation.

Pyroptosis: a new insight into intestinal inflammation and cancer

Pyroptosis is an innate immune response triggered by the activation of inflammasomes by various influencing factors, characterized by cell destruction. It impacts the immune system and cancer immunotherapy. In recent years, the roles of pyroptosis and inflammasomes in intestinal inflammation and cancer have been continuously confirmed. This article reviews the latest progress in pyroptosis mechanisms, new discoveries of inflammasomes, mutual regulation between inflammasomes, and their applications in intestinal diseases. Additionally, potential synergistic treatment mechanisms of intestinal diseases with pyroptosis are summarized, and challenges and future directions are discussed, providing new ideas for pyroptosis therapy.

Traditional Chinese medicines and natural products targeting immune cells in the treatment of metabolic-related fatty liver disease

MAFLD stands for metabolic-related fatty liver disease, which is a prevalent liver disease affecting one-third of adults worldwide, and is strongly associated with obesity, hyperlipidemia, and type 2 diabetes. It encompasses a broad spectrum of conditions ranging from simple liver fat accumulation to advanced stages like chronic inflammation, tissue damage, fibrosis, cirrhosis, and even hepatocellular carcinoma. With limited approved drugs for MAFLD, identifying promising drug targets and developing effective treatment strategies is essential. The liver plays a critical role in regulating human immunity, and enriching innate and adaptive immune cells in the liver can significantly improve the pathological state of MAFLD. In the modern era of drug discovery, there is increasing evidence that traditional Chinese medicine prescriptions, natural products and herb components can effectively treat MAFLD. Our study aims to review the current evidence supporting the potential benefits of such treatments, specifically targeting immune cells that are responsible for the pathogenesis of MAFLD. By providing new insights into the development of traditional drugs for the treatment of MAFLD, our findings may pave the way for more effective and targeted therapeutic approaches.