The most common form of primary liver malignancy is hepatocellular carcinoma (HCC)

Fibrogenic progression of chronic liver disease, whatever the etiology, is characterized by persistent chronic parenchymal injury, chronic activation of inflammatory response, and sustained activation of liver fibrogenesis, and of pathological wound healing response. A critical role in liver fibrogenesis is played by hepatic myofibroblasts (MFs), a heterogeneous population of α smooth-muscle actin—positive cells that originate from various precursor cells through a process of activation and transdifferentiation. In this review, we focus the attention on the role of extracellular signal-regulated kinase (ERK) signaling pathway as a critical one in modulating selected profibrogenic phenotypic responses operated by liver MFs. We will also analyze major therapeutic antifibrotic strategies developed in the last two decades in preclinical studies, some translated to clinical conditions, designed to interfere directly or indirectly with the Ras/Raf/MEK/ERK signaling pathway in activated hepatic MFs, but that also significantly increased our knowledge on the biology and pathobiology of these fascinating profibrogenic cells.

Hepatocellular carcinoma is the most common primary liver cancer, ranking third among the leading causes of cancer-related mortality worldwide and whose incidence varies according to geographical area and ethnicity. Metabolic rewiring was recently introduced as an emerging hallmark able to affect tumor progression by modulating cancer cell behavior and immune responses. This review focuses on the recent studies examining HCC’s metabolic traits, with particular reference to the alterations of glucose, fatty acid and amino acid metabolism, the three major metabolic changes that have gained attention in the field of HCC. After delivering a panoramic picture of the peculiar immune landscape of HCC, this review will also discuss how the metabolic reprogramming of liver cancer cells can affect, directly or indirectly, the microenvironment and the function of the different immune cell populations, eventually favoring the tumor escape from immunosurveillance.

Liver fibrosis is a potentially reversible pathophysiological event, leading to excess deposition of extracellular matrix (ECM) components and taking place as the net result of liver fibrogenesis, a dynamic and highly integrated process occurring during chronic liver injury of any etiology. Liver fibrogenesis and fibrosis, together with chronic inflammatory response, are primarily involved in the progression of chronic liver diseases (CLD). As is well known, a major role in fibrogenesis and fibrosis is played by activated myofibroblasts (MFs), as well as by macrophages and other hepatic cell populations involved in CLD progression. In the present review, we will focus the attention on the emerging pathogenic role of hypoxia, hypoxia-inducible factors (HIFs) and related mediators in the fibrogenic progression of CLD.

Non-Alcoholic Fatty Liver Disease (NAFLD) is a major form of chronic liver disease in the general population in relation to its high prevalence among overweight/obese individuals and patients with diabetes type II or metabolic syndrome. NAFLD can progress to steatohepatitis (NASH), fibrosis and cirrhosis and end-stage of liver disease but mechanisms involved are still incompletely characterized. Within the mechanisms proposed to mediate the progression of NAFLD, lipotoxicity is believed to play a major role. In the present study we provide data suggesting that microvesicles (MVs) released by fat-laden cells undergoing lipotoxicity can activate NLRP3 inflammasome following internalization by either cells of hepatocellular origin or macrophages. Inflammasome activation involves NF-kB-mediated up-regulation of NLRP3, pro-caspase-1 and pro-Interleukin-1, then inflammasome complex formation and Caspase-1 activation leading finally to an increased release of IL-1β. Since the release of MVs from lipotoxic cells and the activation of NLRP3 inflammasome have been reported to occur in vivo in either clinical or experimental NASH, these data suggest a novel rational link between lipotoxicity and increased inflammatory response.