NFE2-Related transcription factor 2 coordinates antioxidant defense with thyroglobulin production and iodination in the thyroid gland

Background: The thyroid gland has a special relationship with oxidative stress. While generation of oxidative substances is part of normal iodide metabolism during thyroid hormone synthesis, the gland must also defend itself against excessive oxidation in order to maintain normal function. Antioxidant and detoxification enzymes aid thyroid cells to maintain homeostasis by ameliorating oxidative insults, including during exposure to excess iodide, but the factors that coordinate their expression with the cellular redox status are not known. The antioxidant response system comprising the ubiquitously expressed NFE2-related transcription factor 2 (Nrf2) and its redox-sensitive cytoplasmic inhibitor Kelch-like ECH-associated protein 1 (Keap1) defends tissues against oxidative stress, thereby protecting against pathologies that relate to DNA, protein, and/or lipid oxidative damage. Thus, it was hypothesized that Nrf2 should also have important roles in maintaining thyroid homeostasis. Methods: Ubiquitous and thyroid-specific male C57BL6J Nrf2 knockout (Nrf2-KO) mice were studied. Plasma and thyroids were harvested for evaluation of thyroid function tests by radioimmunoassays and of gene and protein expression by real-time polymerase chain reaction and immunoblotting, respectively. Nrf2-KO and Keap1-KO clones of the PCCL3 rat thyroid follicular cell line were generated using CRISPR/Cas9 technology and were used for gene and protein expression studies. Software-predicted Nrf2 binding sites on the thyroglobulin enhancer were validated by site-directed in vitro mutagenesis and chromatin immunoprecipitation. Results: The study shows that Nrf2 mediates antioxidant transcriptional responses in thyroid cells and protects the thyroid from oxidation induced by iodide overload. Surprisingly, it was also found that Nrf2 has a dramatic impact on both the basal abundance and the thyrotropin-inducible intrathyroidal abundance of thyroglobulin (Tg), the precursor protein of thyroid hormones. This effect is mediated by cell-autonomous regulation of Tg gene expression by Nrf2 via its direct binding to two evolutionarily conserved antioxidant response elements in an upstream enhancer. Yet, despite upregulating Tg levels, Nrf2 limits Tg iodination both under basal conditions and in response to excess iodide. Conclusions: Nrf2 exerts pleiotropic roles in the thyroid gland to couple cell stress defense mechanisms to iodide metabolism and the thyroid hormone synthesis machinery, both under basal conditions and in response to excess iodide.Fil: Ziros, Panos G. Lausanne University; SuizaFil: Habeos, Ioannis. Patras University; GreciaFil: Chartoumpekis, Dionysios V. University of Pittsburgh; Estados UnidosFil: Ntalampyra, Eleni. Universite de Lausanne; SuizaFil: Somm, Emmanuel. Universite de Lausanne; SuizaFil: Renaud, Cédric O.. Universite de Lausanne; SuizaFil: Bongiovanni, Massimo. Institute Of Pathology Locarno; SuizaFil: Trougakos, Ioannis P. Universidad Nacional y Kapodistríaca de Atenas; GreciaFil: Yamamoto, Masayuki. University Of Tohoku; JapónFil: Kensler, Thomas W.. University of Pittsburgh at Johnstown; Estados UnidosFil: Santisteban, Pilar. Universidad Autónoma de Madrid; EspañaFil: Carrasco, Nancy. University of Yale. School of Medicine; Estados UnidosFil: Ris Stalpers, Carrie. Academic Medical Center; Países BajosFil: Amendola, Elena. Universidad de Nápoles; ItaliaFil: Liao, Xiao-Hui. University of Chicago; Estados UnidosFil: Rossich, Luciano Esteban. Comisión Nacional de Energía Atómica de Argentina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Thomasz, Lisa. Comisión Nacional de Energía Atómica de Argentina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Juvenal, Guillermo Juan. Comisión Nacional de Energía Atómica de Argentina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Refetoff, Samuel. University of Chicago; Estados UnidosFil: Sykiotis, Gerasimos P.. Universite de Lausanne; Suiz

EMT Factors and Metabolic Pathways in Cancer.

The epithelial-mesenchymal transition (EMT) represents a biological program during which epithelial cells lose their cell identity and acquire a mesenchymal phenotype. EMT is normally observed during organismal development, wound healing and tissue fibrosis. However, this process can be hijacked by cancer cells and is often associated with resistance to apoptosis, acquisition of tissue invasiveness, cancer stem cell characteristics, and cancer treatment resistance. It is becoming evident that EMT is a complex, multifactorial spectrum, often involving episodic, transient or partial events. Multiple factors have been causally implicated in EMT including transcription factors (e.g., SNAIL, TWIST, ZEB), epigenetic modifications, microRNAs (e.g., miR-200 family) and more recently, long non-coding RNAs. However, the relevance of metabolic pathways in EMT is only recently being recognized. Importantly, alterations in key metabolic pathways affect cancer development and progression. In this review, we report the roles of key EMT factors and describe their interactions and interconnectedness. We introduce metabolic pathways that are involved in EMT, including glycolysis, the TCA cycle, lipid and amino acid metabolism, and characterize the relationship between EMT factors and cancer metabolism. Finally, we present therapeutic opportunities involving EMT, with particular focus on cancer metabolic pathways

The Transcriptomic Response of the Murine Thyroid Gland to Iodide Overload and the Role of the Nrf2 Antioxidant System

Background: Thyroid follicular cells have physiologically high levels of reactive oxygen species because oxidation of iodide is essential for the iodination of thyroglobulin (Tg) during thyroid hormone synthesis. Thyroid follicles (the functional units of the thyroid) also utilize incompletely understood autoregulatory mechanisms to defend against exposure to excess iodide. To date, no transcriptomic studies have investigated these phenomena in vivo. Nuclear erythroid factor 2 like 2 (Nrf2 or Nfe2l2) is a transcription factor that regulates the expression of numerous antioxidant and other cytoprotective genes. We showed previously that the Nrf2 pathway regulates the antioxidant defense of follicular cells, as well as Tg transcription and Tg iodination. We, thus, hypothesized that Nrf2 might be involved in the transcriptional response to iodide overload. Methods: C57BL6/J wild-type (WT) or Nrf2 knockout (KO) male mice were administered regular water or water supplemented with 0.05% sodium iodide for seven days. RNA from their thyroids was prepared for next-generation RNA sequencing (RNA-Seq). Gene expression changes were assessed and pathway analyses were performed on the sets of differentially expressed genes. Results: Analysis of differentially expressed messenger RNAs (mRNAs) indicated that iodide overload upregulates inflammatory-, immune-, fibrosis- and oxidative stress-related pathways, including the Nrf2 pathway. Nrf2 KO mice showed a more pronounced inflammatory–autoimmune transcriptional response to iodide than WT mice. Compared to previously published datasets, the response patterns observed in WT mice had strong similarities with the patterns typical of Graves’ disease and papillary thyroid carcinoma (PTC). Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) also responded to iodide overload, with the latter targeting mRNAs that participate mainly in inflammation pathways. Conclusions: Iodide overload induces the Nrf2 cytoprotective response and upregulates inflammatory, immune, and fibrosis pathways similar to autoimmune hyperthyroidism (Graves’ disease) and PTC

Differential Expression of MicroRNAs in Adipose Tissue after Long-Term High-Fat Diet-Induced Obesity in Mice

Obesity is a major health concern worldwide which is associated with increased risk of chronic diseases such as metabolic syndrome, cardiovascular disease and cancer. The elucidation of the molecular mechanisms involved in adipogenesis and obesogenesis is of essential importance as it could lead to the identification of novel biomarkers and therapeutic targets for the development of anti-obesity drugs. MicroRNAs (miRNAs) have been shown to play regulatory roles in several biological processes. They have become a growing research field and consist of promising pharmaceutical targets in various fields such as cancer, metabolism, etc. The present study investigated the possible implication of miRNAs in adipose tissue during the development of obesity using as a model the C57BLJ6 mice fed a high-fat diet

The Role of Aldosterone and the Mineralocorticoid Receptor in Metabolic Dysfunction-Associated Steatotic Liver Disease

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) is one of the fastest-growing hepatic disorders worldwide. During its natural course, MASLD tends to progress from isolated steatosis of the liver to Metabolic Dysfunction-Associated Alcoholic Steatohepatitis (MASH), advanced fibrosis, and finally cirrhosis, with the risk of developing hepatocellular carcinoma (HCC). Although frequently related to overweight or obesity and other components of the metabolic syndrome (MS), MASLD can also be present in individuals without such risk factors. The mechanisms leading to MASLD are incompletely elucidated and may involve many proinflammatory and pro-fibrotic pathways, disrupted biliary acid homeostasis, and gut microbiota dysbiosis. Aldosterone and its interaction with the mineralocorticoid receptor (MR) are thought to participate in the pathogenesis of MASLD through the modulation of inflammation and fibrosis. Remarkably, blockade of the MR in experimental models was shown to improve MASH and fibrosis through mechanisms that need further characterization. So far, however, few clinical studies have explored the effect of MR blockade in the management of MASH and associated fibrosis. This review is intended to summarize the recent animal and human data concerning the interaction between MR pathways and MASLD

Keap1/Nrf2 pathway in the frontiers of cancer and non-cancer cell metabolism

Cancer cells adapt their metabolism to their increased needs for energy and substrates for protein, lipid and nucleic acid synthesis. Nuclear erythroid factor 2-like 2 (Nrf2) pathway is usually activated in cancers and has been suggested to promote cancer cell survival mainly by inducing a large battery of cytoprotective genes. This mini review focuses on metabolic pathways, beyond cytoprotection, which can be directly or indirectly regulated by Nrf2 in cancer cells to affect their survival. The pentose phosphate pathway (PPP) is enhanced by Nrf2 in cancers and aids their growth. PPP has also been found to be up-regulated in non-cancer tissues and other pathways, such as de novo lipogenesis, have been found to be repressed after activation of the Nrf2 pathway. The importance of these Nrf2-regulated metabolic pathways in cancer compared with non-cancer state remains to be determined. Last but not least, the importance of context about Nrf2 and cancer is highlighted as the Nrf2 pathway may be activated in cancers but its pharmacological activators are useful in chemoprevention.</jats:p

A Bibliometric Review of the Keap1/Nrf2 Pathway and its Related Antioxidant Compounds

Nrf2 is a master transcriptional regulator of antioxidant and cytoprotective pathways. Currently in its third decade, research on Nrf2 has expanded to encompass not only basic but also clinical studies. In the present bibliometric review, we employed the VOSviewer tool to describe the existing Nrf2 literature landscape. As of July 2019, 11,931 papers on Nrf2 were listed in the “Web of Science” database, with more than 1000 new papers published each year. As expected, terms related to oxidative stress and antioxidant molecules occur very often in the Nrf2 literature throughout the years. Interestingly, there is also a gradual increase in the occurrence of terms related to diseases or to natural compounds, the most prominent being sulforaphane, curcumin, and resveratrol that modulate the Nrf2 pathway. Going beyond molecular biology/biochemistry and related fields, Nrf2 research has begun to spread into more clinical areas like endocrinology/metabolism, cardiology, and nephrology, likely reflecting an increased interest in clinical applications of Nrf2 pathway activators. China has become the most prolific producer of Nrf2 papers the last five years followed by the USA and Japan, a reverse pattern compared to the past. In conclusion, Nrf2 is the subject of a globally active research field that keeps growing and extends from bench to bedside.</jats:p

Patent Review (2017–2020) of the Keap1/Nrf2 Pathway Using PatSeer Pro: Focus on Autoimmune Diseases

Research on the antioxidant pathway comprising the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and its cytoplasmic inhibitor Kelch-like ECH-associated protein 1 (Keap1) is ever increasing. As modulators of this pathway have started to be used in clinical trials and clinical practice, Nrf2 has become the subject of several patents. To assess the patent landscape of the last three years on Nrf2 and evaluate the main fields they refer to, we used the web-based tool PatSeer Pro to identify patents mentioning the Nrf2 pathway between January 2017 and May 2020. This search resulted in 509 unique patents that focus on topics such as autoimmune, neurodegenerative, liver, kidney, and lung diseases and refer to modulators (mainly activators) of the Nrf2 pathway as potential treatments. Autoimmunity emerged as the main theme among the topics of Nrf2 patents, including a broad range of diseases, such as systemic sclerosis, systemic lupus erythematosus, multiple sclerosis, inflammatory bowel diseases, Hashimoto’s thyroiditis, etc.; however, there was a dearth of experimental support for the respective patents’ claims. Given that chronic inflammation is the main element of the pathophysiology of most autoimmune diseases, the majority of patents referring to activation of Nrf2 as a method to treat autoimmune diseases base their claims on the well-established anti-inflammatory role of Nrf2. In conclusion, there is strong interest in securing intellectual property rights relating to the potential use of Nrf2 pathway activators in a variety of diseases, and this trend parallels the rise in related research publications. However, in the case of autoimmunity, more research is warranted to support the potential beneficial effects of Nrf2 modulation in each disease.</jats:p