In recent years, cellular senescence has generated a lot of interest among researchers because of its involvement in both the normal aging process and common human diseases. During senescence, cells undergo alterations that include telomere shortening, nuclear area enlargement, and genomic and mitochondrial DNA damage, leading to irreversible cell cycle arrest, and secretion of proinflammatory cytokines. Evidence suggests that the complex process of senescence is involved in the development of a plethora of chronic diseases including metabolic and inflammatory disorders and tumorigenesis. Recently, several human and animal studies have emphasized the involvement of senescence in the pathogenesis and development of liver steatosis including the progression to nonalcoholic steatohepatitis (NASH) as characterized by the additional emergence of inflammation, hepatocyte ballooning, and liver fibrosis. The development of nonalcoholic fatty liver disease (NAFLD) and its progression to NASH are commonly accompanied by several pathophysiological events including metabolic dysregulation and inflammatory phenomena occurring within the liver that may contribute to or derive from cellular senescence, implying that the latter may be both a stimulus and a consequence of the disease. Conclusion: In this review, we summarize the current literature on the impact of cellular senescence in NAFLD/NASH and discuss the effectiveness and safety of novel senolytic drugs and therapeutic options available to delay or treat the disease. Finally, we identify the open questions and issues to be addressed in the near future.

Senescence is considered to be a cardinal player in several chronic inflammatory and metabolic pathologies. The two dominant mechanisms of senescence include replicative senescence, predominantly depending on age-induced telomere shortening, and stress-induced senescence, triggered by external or intracellular harmful stimuli. Recent data indicate that hepatocyte senescence is involved in the development of nonalcoholic fatty liver disease (NAFLD). However, previous studies have mainly focused on age-related senescence during NAFLD, in the presence or absence of obesity, while information about whether the phenomenon is characterized by replicative or stress-induced senescence, especially in non-aged organisms, is scarce. Herein, we subjected young mice to two different diet-induced NAFLD models which differed in the presence of obesity. In both models, liver fat accumulation and increased hepatic mRNA expression of steatosis-related genes were accompanied by hepatic senescence, indicated by the increased expression of senescence-associated genes and the presence of a robust hybrid histo-/immunochemical senescence-specific staining in the liver. Surprisingly, telomere length and global DNA methylation did not differ between the steatotic and the control livers, while malondialdehyde, a marker of oxidative stress, was upregulated in the mouse NAFLD livers. These findings suggest that senescence accompanies NAFLD emergence, even in non-aged organisms, and highlight the role of stress-induced senescence during steatosis development independently of obesity.

Affecting one fourth of the global population, non-alcoholic fatty liver disease (NAFLD) is the commonest chronic liver disorder. It encompasses the simple liver fat accumulation to more progressive steatosis, inflammation, and fibrosis characterized as non-alcoholic steatohepatitis (NASH) and in some cases cirrhosis and hepatocellular carcinoma. NAFLD regularly coexists with metabolic disorders, such as obesity and mostly type 2 diabetes mellitus (T2DM). A relatively new class of antidiabetic drugs, the sodium glucose co-transporter 2 (SGLT2) inhibitors exert their action by increasing the urinary glucose and calorie excretion leading to ameliorated plasma glucose levels and lower bodyweight. Recently, several animal studies and human clinical trial have emphasized the possible beneficial impact of SGLT2 inhibitors on NAFLD and its progression to NASH. In this present review, we summarize the current literature regarding the efficacy of the aforementioned category of drugs on anthropometric, laboratory, and histological features of patients with NAFLD. Conclusively, as SGLT2 inhibitors seem to be an appealing therapeutic opportunity for NAFLD management, we identify the open issues and questions to be addressed in order to clarify the impact in choosing antidiabetic medication to treat NAFLD patients associated with T2DM.

Background: Hippo signaling pathway de-regulation has been strongly associated with tumorigenesis, metastasis, and drug resistance. Pregnancy-associated breast cancer, the most frequently diagnosed malignancy during gestation, demonstrates an intricate molecular nature. The aim of the present study is to evaluate Hippo pathway transducers TAZ and YAP1 expression in pregnancy-associated breast cancer in relation to the clinicopathological characteristics of the disease.Methods: Formalin-fixed paraffin-embedded tissues from 21 PABC patients treated at Alexandra Hospital in Athens, Greece were immunohistochemically analyzed. Statistical analysis was performed to investigate a possible correlation among the Hippo pathway signaling and the clinical features of the disease.Results: In 48% of patients included in the study strong nuclear TAZ/YAP1 staining in tumor cells was identified. Additionally, the hormone receptor negative status was statistically correlated with strong positivity of the TAZ/YAP1 co-transcriptional factors. No association was observed with the overall-survival and the disease-free survival rate. Conclusions: Hippo pathway is proven to be de-regulated in a subset of pregnancy-associated breast cancer patients highlighting the complex molecular background of the disease which certainly requires further investigation.

Background/Aim: The Hippo pathway is a molecular pathway recently associated with tumorigenesis, metastasis, and drug resistance. Pregnancy-associated breast cancer (PABC) is the most common malignancy diagnosed during gestation; however, the molecular mechanisms underlying PABC are largely unknown. The aim of the present study was to evaluate Hippo pathway transducers TAZ and YAP1 expression in PABC in relation to the clinicopathological characteristics of the disease. Patients and Methods: Formalinfixed paraffin-embedded (FFPE) tissues from 21 PABC patients treated at Alexandra Hospital in Athens, Greece, were analyzed with immunohistochemistry. Results: Strong nuclear TAZ/YAP1 stanning was found in 48% of the PABC patients analyzed. Hormone receptor negative patients had a statistically significant correlation with strong positive expression of TAZ/YAP1 co-transcription factors. No association was observed with overall and disease-free survival. Conclusion:The Hippo pathway is de-regulated in a subset of PABC patients, highlighting the complex molecular background of the disease, which certainly requires further investigation.