Statin can reduce the risk of hepatocellular carcinoma among patients with nonalcoholic fatty liver disease: a systematic review and meta-analysis

Currently, nonalcoholic fatty liver disease (NAFLD) is the main cause of chronic liver disease and liver-related mortality worldwide. Hepatocellular carcinoma (HCC) is a fatal complication in patients with NAFLD. However, whether statins can reduce the risk of HCC in patients with NAFLD remains controversial. We aimed to determine the relationship between statin use and HCC occurrence among patients with NAFLD. We independently retrieved related studies from PubMed, EMBASE, Cochrane Library, Web of Science, and ClinicalTrial.gov (from 1 January 2000 to 27 February 2022). The main outcome was the development of HCC. A fixed-effects model was used to merge odds ratio (OR) in the meta-analysis. Five studies involving 684 363 patients were included. The results of the meta-analysis suggested a significantly lower risk of HCC among statin users with NAFLD [OR = 0.59; 95% confidence interval (CI), 0.39-0.89; I2 = 87.90%]. Additionally, a lower risk of HCC was observed among patients with NAFLD aged less than 65 years (OR = 0.59; 95% CI, 0.46-0.77; I2 = 20.50%). Statins can reduce the risk of HCC in patients aged less than 65 years with NAFLD.

Cathepsin B deficiency ameliorates liver lipid deposition, inflammatory cell infiltration, and fibrosis after diet-induced nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a severe form of nonalcoholic fatty liver disease characterized by fat accumulation and inflammation in liver. Yet, the mechanistic insight and diagnostic and therapeutic options of NASH remain incompletely understood. This study tested the roles of cysteine protease cathepsin B (CatB) in mouse NASH development. Immunoblot revealed increased liver CatB expression in NASH mice. Fructose-palmitate-cholesterol diet increased body weight gain, liver to body weight ratio, blood fasting glucose, plasma total cholesterol and alanine transaminase levels, and liver triglyceride, but decreased plasma high-density lipoprotein in wild-type mice. All these changes were blunted in CatB-deficient (Ctsb^-/-) mice. In parallel to reduced expression of genes involved in liver lipid transport and lipogenesis, liver CD36, FABP4, and PPARγ protein levels were also significantly decreased in Ctsb^-/- mice, although CatB deficiency did not affect liver gluconeogenesis and fatty acid beta-oxidation-associated gene expression. Mechanistic studies showed that CatB deficiency decreased liver expression of adhesion molecules, inflammatory cytokine, and chemokine, along with reduced liver inflammatory cell infiltration. CatB deficiency also promoted M2 macrophage polarization and reduced liver TGF-β1 signaling and fibrosis. Together, CatB deficiency improves liver function in NASH mice by suppressing de novo lipogenesis and liver inflammation and fibrosis.

Cellular senescence and liver disease: Mechanisms and therapeutic strategies

Cellular senescence is a fundamental cell fate caused by several cellular injuries which results in irreversible cell cycle arrest yet remaining metabolically active across all species. Cellular senescence not only can prevent tumor occurrence by inhibiting the proliferation of injured cells, but also can affect the surrounding cells through the senescence-associated secretory phenotype (SASP). Attractively, accumulating evidence shows that cellular senescence is closely related to various liver diseases. Therapeutic opportunities based on targeting senescent cells and the SASP are considered to be potential strategy for liver diseases. However, although research on cell senescence has attracted widespread attention, the overview on detailed mechanism and biological function of cell senescence in liver disease is still largely unknown. The present review summarizes the specific role of cell senescence in various liver diseases, and updates the molecular mechanisms underlying cell senescence. Moreover, the review also explores new strategies for prevention and treatment of liver disease through promoting senescence or counteracting excessive pathological senescence.

Exercise, oxidants, and antioxidants change the shape of the bell-shaped hormesis curve

It is debated whether exercise-induced ROS production is obligatory to cause adaptive response. It is also claimed that antioxidant treatment could eliminate the adaptive response, which appears to be systemic and reportedly reduces the incidence of a wide range of diseases. Here we suggest that if the antioxidant treatment occurs before the physiological function-ROS dose-response curve reaches peak level, the antioxidants can attenuate function. On the other hand, if the antioxidant treatment takes place after the summit of the bell-shaped dose response curve, antioxidant treatment would have beneficial effects on function. We suggest that the effects of antioxidant treatment are dependent on the intensity of exercise, since the adaptive response, which is multi pathway dependent, is strongly influenced by exercise intensity. It is further suggested that levels of ROS concentration are associated with peak physiological function and can be extended by physical fitness level and this could be the basis for exercise pre-conditioning. Physical inactivity, aging or pathological disorders increase the sensitivity to oxidative stress by altering the bell-shaped dose response curve.

Statins in oncological research: from experimental studies to clinical practice

Statins, 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors are commonly used drugs in the treatment of dyslipidemias, primarily raised cholesterol. Recently, many epidemiological and preclinical studies pointed to anti-tumor properties of statins, including anti-proliferative activities, apoptosis, decreased angiogenesis and metastasis. These processes play an important role in carcinogenesis and, therefore, the role of statins in cancer disease is being seriously discussed among oncologists. Anti-neoplastic properties of statins combined with an acceptable toxicity profile in the majority of individuals support their further development as anti-tumor drugs. The mechanism of action, current preclinical studies and clinical efficacy of statins are reviewed in this paper. Moreover, promising results have been reported regarding the statins' efficacy in some cancer types, especially in esophageal and colorectal cancers, and hepatocellular carcinoma. Statins' hepatotoxicity has traditionally represented an obstacle to the prescription of this class of drugs and this issue is also discussed in this review.

Hepatic steatosis and steatohepatitis: Are they really two distinct entities?

Non-alcoholic fatty liver disease affects nearly 30% of Americans. A histopathological spectrum exists from simple steatosis to NASH which may progress to cirrhosis and HCC. NASH is currently the third most common indication for liver transplant with increasing incidence. Steatosis can be considered the hepatic manifestation of the metabolic syndrome as insulin resistance is a major risk factor for its development. While liver biopsy is the gold standard for diagnosis, non-invasive methods are currently being developed to appropriately determine who needs histologic evaluation. Management focuses on mitigation of risk factors, since targeted therapies to halt progression of fibrosis have not been validated. Simple steatosis does not affect overall survival, but NASH conveys increased mortality. Because of this, non-invasive strategies to diagnose patients and management algorithms are needed. This review supports the definitions of simple steatosis and NASH as two distinct entities based on pathophysiology, diagnosis, management, and prognosis.

Pharmacological agents for nonalcoholic steatohepatitis

The rationale for specific pharmacologic therapy in nonalcoholic steatohepatitis (NASH) is determined by the potential for disease progression and the difficulties, in many patients, to successfully implement diet and lifestyle changes in the long term. Because they correct insulin resistance, insulin-sensitizing agents are attractive candidates for the treatment of NASH. However, two randomized studies have shown that vitamin E, despite having no effect on insulin sensitivity, achieves interesting histological and biochemical efficacy. This review provides an insight into the therapeutic efficacy and safety issues of different pharmacological agents tested in human NASH.