Hepatic stellate cell (HSC), initially analyzed by von Kupffer, in 1876, revealed to be an extraordinary mesenchymal cell, essential for both hepatocellular function and lesions, being the hallmark of hepatic fibrogenesis and carcinogenesis. Apart from their implications in hepatic injury, HSCs play a vital role in liver development and regeneration, xenobiotic response, intermediate metabolism, and regulation of immune response. In this review, we discuss the current state of knowledge regarding HSCs morphology, human HSCs markers and human HSC cell lines. We also summarize the latest findings concerning their roles in normal and liver pathology, focusing on their impact in fibrogenesis, chronic viral hepatitis and liver tumors.

The central nervous system (CNS) represents a complex network of different cells, such as neurons, glial cells, and blood vessels. In tumor pathology, glial cells result in the highest number of cancers, and glioblastoma (GB) is considered the most lethal tumor in this region. The development of GB leads to the infiltration of healthy tissue through the interaction between all the elements of the brain network. This results in a GB microenvironment, a complex peritumoral hallo composed of tumor cells and several non-tumor cells (e.g., nervous cells, stem cells, fibroblasts, vascular and immune cells), which might be the principal factor for the ineffective treatment due to the fact that the microenvironment modulates the biologic status of the tumor with the increase in its evasion capacity. Crosstalk between glioma cells and the brain microenvironment finally inhibits the beneficial action of molecular pathways, favoring the development and invasion of the tumor and its increasing resistance to treatment. A deeper understanding of cell–cell interactions in the tumor microenvironment (TME) and with the tumor cells could be the basis for a more efficient therapy.

The tumor microenvironment is a highly dynamic accumulation of resident and infiltrating tumor cells, responsible for growth and invasion. The authors focused on the leading-edge concepts regarding the glioblastoma microenvironment. Due to the fact that the modern trend in the research and treatment of glioblastoma is represented by multiple approaches that target not only the primary tumor but also the neighboring tissue, the study of the microenvironment in the peritumoral tissue is an appealing direction for current and future therapies.

Background and Aims: The aim of this study is to determine whether activated hepatic stellate cells (HSCs) may represent a prognostic marker of progressive liver fibrosis in chronic viral hepatitis C (VHC) before antiviral therapy. The possible correlation between HSCs immunohistochemical features, histopathological aspects and clinical data before therapy were also studied. Methods: This retrospective pilot study was conducted on 27 liver biopsies from VHC patients before antiviral therapy. HSCs’s immunohistochemical analysis used the antibodies alpha-smooth muscle actin (α-SMA), glial fibrillary acidic protein (GFAP) and vinculin. We correlated immunopositive HSCs with HCV load, liver stiffness (LS), fibrosis stage and necro-inflammatory degree before treatment. Also, we assessed the association between liver fibrosis after therapy, the sustained virological response at 12 weeks after therapy (SVR 12) and the type of therapy. Results: HSCs were increased in VHC patients compared to controls, mainly in the intermediate and periportal lobular regions. α-SMA and vinculin HSCs correlated positively with fibrosis stage (p=0.044), (p=0.028). Furthermore, α-SMA and vinculin HSCs were associated with LS (p=0.027), (p=0.002) and viral load (p=0.021), (p=0.006), but not with necro-inflammation degree. GFAP HSCs inversely correlated with fibrosis stage (r= -0.475), LS (r= -0.422) and HCV load (r= -0.517), but positively with necro-inflammation degree (p=0.038). Liver fibrosis post therapy correlated positively with SVR12 (p<0.001) and the type of therapy (p=0.006) and SVR12 correlated positively with treatment’s type (p=0.002). Conclusions: Activated HSCs may represent a marker of increased liver fibrosis in VHC. Different immunohistochemical markers can detect various HSCs subpopulations involved in the evolution of VHC and liver fibrosis.

This article focuses on the latest histological knowledge in the field regarding the peripheral lymphoid system [mucosa-associated lymphoid tissue (MALT), bronchus-associated lymphoid tissue (BALT), gut-associated lymphoid tissue (GALT)], the thymus stroma, some of the various corpuscles of the human body (Hassall's corpuscles in thymus, arenaceous corpuscles in pineal gland, corpora amylacea in prostate and other locations) and Fañanas glial cells in the cerebellum.