Epstein-Barr Virus Facilitates Expression of KLF14 by Regulating the Cooperative Binding of the E2F-Rb-HDAC Complex in Latent Infection

Kruppel-like factor 14 ameliorated obesity and related metabolic disorders by promoting adipose tissue browning

Obesity has been identified as a serious and debilitating disease that threatens human health, but the current treatment strategies still have some shortcomings. Exercise and dieting are difficult for many people to adhere to, and a series of surgical risks and pain brought about by volume reduction have made it difficult for the current weight loss effect to meet human expectations. In this study, we first found that mice with overexpression of the transcription factor Kruppel-like factor 14 (KLF14) in subcutaneous adipose tissue gained weight more slowly while consuming a high-fat diet than did control mice, and these mice also showed reduced insulin resistance and liver lipid deposition abnormalities. Mechanistically, the browning of white adipose tissue was promoted in adipose tissue with KLF14 overexpression; therefore, we preliminarily concluded that KLF14 can improve obesity by promoting the browning of white adipose tissue and energy consumption, thus ameliorating obesity and related metabolic disturbances. In summary, our results revealed that KLF14 may promote white adipose tissue browning, thus ameliorating high-fat diet-induced obesity and hepatic steatosis, as well as serum lipid levels and insulin resistance, thereby achieving a positive effect on metabolism.NEW & NOTEWORTHY Our study first explored the role of KLF14 in the development and progression of HFD-induced obesity in male mice. Its beneficial effect on adipose browning and metabolic disorders suggests that KLF14 may provide us a new therapeutic strategy for obesity and related metabolic complications. This health problem is of global concern and needs to be addressed.

Comprehensive insight into altered host cell-signaling cascades upon Helicobacter pylori and Epstein-Barr virus infections in cancer

Cancer is characterized by mutagenic events that lead to disrupted cell signaling and cellular functions. It is one of the leading causes of death worldwide. Literature suggests that pathogens, mainly Helicobacter pylori and Epstein-Barr virus (EBV), have been associated with the etiology of human cancer. Notably, their co-infection may lead to gastric cancer. Pathogen-mediated DNA damage could be the first and crucial step in the carcinogenesis process that modulates numerous cellular signaling pathways. Altogether, it dysregulates the metabolic pathways linked with cell growth, apoptosis, and DNA repair. Modulation in these pathways leads to abnormal growth and proliferation. Several signaling pathways such RTK, RAS/MAPK, PI3K/Akt, NFκB, JAK/STAT, HIF1α, and Wnt/β-catenin are known to be altered in cancer. Therefore, this review focuses on the oncogenic roles of H. pylori, EBV, and its associated signaling cascades in various cancers. Scrutinizing these signaling pathways is crucial and may provide new insights and targets for preventing and treating H. pylori and EBV-associated cancers.

Epigenetic control of the Epstein-Barr lifecycle

Epstein-Barr virus (EBV) infects 95% of adults worldwide, causes infectious mononucleosis, is etiologically linked to multiple sclerosis and is associated with 200 000 cases of cancer each year. EBV manipulates host epigenetic pathways to switch between a series of latency programs and to reactivate from latency in order to colonize the memory B-cell compartment for lifelong infection and to ultimately spread to new hosts. Here, we review recent advances in the understanding of epigenetic mechanisms that control EBV latency and lytic gene expression in EBV-transformed B and epithelial cells. We highlight newly appreciated roles of DNA methylation epigenetic machinery, host histone chaperones, the Hippo pathway, m6A RNA modification and nonsense mediated decay in control of the EBV lifecycle.

Metabolic Control by DNA Tumor Virus-Encoded Proteins

Viruses co-opt a multitude of host cell metabolic processes in order to meet the energy and substrate requirements for successful viral replication. However, due to their limited coding capacity, viruses must enact most, if not all, of these metabolic changes by influencing the function of available host cell regulatory proteins. Typically, certain viral proteins, some of which can function as viral oncoproteins, interact with these cellular regulatory proteins directly in order to effect changes in downstream metabolic pathways. This review highlights recent research into how four different DNA tumor viruses, namely human adenovirus, human papillomavirus, Epstein-Barr virus and Kaposi's associated-sarcoma herpesvirus, can influence host cell metabolism through their interactions with either MYC, p53 or the pRb/E2F complex. Interestingly, some of these host cell regulators can be activated or inhibited by the same virus, depending on which viral oncoprotein is interacting with the regulatory protein. This review highlights how MYC, p53 and pRb/E2F regulate host cell metabolism, followed by an outline of how each of these DNA tumor viruses control their activities. Understanding how DNA tumor viruses regulate metabolism through viral oncoproteins could assist in the discovery or repurposing of metabolic inhibitors for antiviral therapy or treatment of virus-dependent cancers.