The conversion of simple steatosis into nonalcoholic steatohepatitis (NASH) in patients with nonalcoholic fatty liver disease (NAFLD) has attracted many attentions in recent years. The role of the hedgehog (HH) pathway in the regulation of lipogenesis has been addressed in the literature. This study aimed to investigate the levels of the sonic hedgehog (SHH) and Indian hedgehog (IHH) ligands and the correlation of these ligands with levels of proteins involved in the transforming growth factor‐β1 (TGF‐β1) pathway, as well as the evaluation of the transcriptional coactivator with PDZ binding motif (TAZ) expression in human simple steatosis, NASH cirrhosis, and controls. Patients were divided into two groups: the first group consisted of patients diagnosed with simple steatosis (n = 16) and the second group included those diagnosed with NASH cirrhosis (n = 15). As a control group, 18 histologically normal liver tissues were collected in this study. The expression of the TGF‐β1pathway components and SHH and IHH ligands were analyzed by means of the quantitative real‐time polymerase chain reaction and western blot analyses. A significant decrease was found in the hepatic expression of the SHH, IHH, and TGF‐β1 pathways along with the expression of TAZ in tissue specimens with simple steatosis in comparison with patients affected by NASH cirrhosis and controls. Also, the levels of SHH and IHH proteins were significantly correlated with the expression of proteins involved in the TGF‐β1 pathway. Moreover, the expression of the HH pathway ligands was positively associated with the expression of TAZ, supporting the notion that TAZ may play a role in the activation of the HH pathway thereby regulating the expression of its ligands. It seems that in patients with NAFLD, the downregulation of the HH pathway ligands may stem from steatosis; however, at the same time, it may prevent the conversion of simple steatosis into NASH in patients with liver diseases. © 2019 IUBMB Life, 71(9):1382–1390, 2019

Numerous investigations have been performed on the role of the transforming growth factor‐β1 (TGF‐β1) pathway in the development of chronic liver diseases (CLDs); however, they failed to explain the underlying mechanism of its pathogenesis, suggesting that other alternative pathways might have been overlooked. The involvement of yes‐associated protein1 (YAP1) has been attributed to liver fibrosis; yet, the precise function of this protein has not been fully understood. Therefore, this study aimed to investigate the activity of the YAP1 pathway in human liver cirrhosis (regardless of its causality) and its correlation with the TGF‐β1 and sonic hedgehog (SHH) pathways. In this case–control study, the immunohistochemical and quantitative real‐time polymerase chain reaction analyses were carried out to determine the activation of the YAP1 pathway in patients with liver cirrhosis (n = 38) and control 1 individuals (n = 10). The western blot analysis and ELISA method were also performed to assess the SHH and TGF‐β1 pathways. Although significantly increased expression of cytoplasmic YAP1 was found in patients with liver cirrhosis (P < 0.045), the rate of the nuclear YAP1 expression was similar to that of the control 1 subjects. Moreover, the hepatic expression of amphiregulin (AREG), known as the YAP1 target, along with proteins involved in the TGF‐β1 pathway was significantly elevated in all cirrhotic patients, compared with the control subjects. Our results showed that the increased activity of the TGF‐β1 pathway is strongly associated with the expression of AREG, denoting a direct and positive relationship between the TGF‐β1 and YAP1 pathways. It seems that, unlike the TGF‐β1 and SHH pathways, the YAP1 pathway does not play a significant role in the development of liver cirrhosis.

The pivotal role of the extracellular matrix (ECM) as both a cause and consequence of liver fibrosis is striking. However, mechanotransducer molecules and profibrogenic factors induced by liver stiffness are still unclear. The current study aimed to investigate liver stiffness and its correlation with the expression of the transcriptional coactivator with PDZ‐binding motif (TAZ) and serum osteopontin (OPN) in human cirrhosis. In this case−control study, liver tissue stiffness was determined using atomic force microscopy in cirrhotic livers (n = 38) of different etiologies and in controls (n = 10). Immunohistochemical and qRT‐PCR analyses were performed to analyze TAZ expression. Besides, western blotting and ELISA were performed to assess liver Indian hedgehog and serum OPN levels, respectively. Liver stiffness, TAZ expression, and hepatic gene expression and serum protein levels of OPN were significantly increased in patients with cirrhosis compared with the control groups (all P < 0.001), specifically in autoimmune‐ and alcohol‐related cirrhosis. In cirrhotic patients, liver stiffness was significantly associated with the expression of nuclear TAZ and OPN. The correlation between matrix stiffness as a mechanical property, TAZ as a potential mechanotransducer, and OPN as a matricellular factor suggests possible effects of mechanical features of the ECM on the expression of the aforementioned profibrogenic markers, which is predominant in autoimmune‐ and alcohol‐related cirrhosis.

Background and aim: Cirrhosis is a major public health problem worldwide. The prevalence of cirrhosis is various in different geographical regions. The aim of the present study was to determine the distribution of the etiologies of cirrhosis and their proportional changes through recent 11 years in Iran. Methods: In this retrospective, observational study, the data of cirrhotic patients who have been listed for liver transplantation in the Namazi Transplant Center (Shiraz, Iran) between January 2006 and December 2016 were analyzed. Demographic and clinical data of the patients including model for end-stage liver disease score, year of registration, and the etiologic diagnosis for each patient were retrieved. Results: The ratio of males to females was the highest (2.6:1) in patients with age over 50 years. Of 4891 patients, hepatitis B virus cirrhosis had the highest frequency (23.53%) and alcoholic cirrhosis had the lowest frequency (1.70%). The percentages of waiting list patients with hepatitis B virus (34.48%–17.48%) (P < 0.001), autoimmune hepatitis (12.64%–8.50%) (P = 0.037), and alcoholic cirrhosis (2.30%–1.10%) were decreased (P = 0.008) and the percentages of waiting list patients with cholestatic (12.64%–25.20%) and nonalcoholic steatohepatitis cirrhosis (0.77%–8.82%) were increased over 11 years (both P < 0.001). Hepatitis B virus and autoimmune hepatitis cirrhosis were the most prevalent in male and female patients, respectively. Conclusion: The results of the present study showed an increase in the frequency of cholestasis and nonalcoholic steatohepatitis cirrhosis and therefore it should be considered in the health policy implementation.