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Lung cancer progression relies on angiogenesis, which is a response to hypoxia typically coordinated by hypoxia- inducible transcription factors (HIFs), but growing evidence indicates that transcriptional programs beyond HIFs control tumor angiogenesis. Here, we show that the redox-sensitive transcription factor BTB and CNC homology 1 (BACH1) controls the transcription of a broad range of angiogenesis genes. BACH1 is stabilized by lowering ROS levels; consequently, angiogenesis gene expression in lung cancer cells, tumor organoids, and xenograft tumors increased substantially following administration of vitamins C and E and N-acetylcysteine in a BACH1-dependent fashion under normoxia. Moreover, angiogenesis gene expression increased in endogenous BACH1-overexpressing cells and decreased in SACH7-knockout cells in the absence of antioxidants. BACH1 levels also increased upon hypoxia and following administration of prolyl hydroxylase inhibitors in both HfF7A-knockout and WT cells. BACH1 was found to be a transcriptional target of HIF1[alpha], but BACH1's ability to stimulate angiogenesis gene expression was HIF1[alpha] independent. Antioxidants increased tumor vascularity in vivo in a BACH1- dependent fashion, and overexpressing BACH1 rendered tumors sensitive to antiangiogenesis therapy. BACH1 expression in tumor sections from patients with lung cancer correlated with angiogenesis gene and protein expression. We conclude that BACH1 is an oxygen- and redox-sensitive angiogenesis transcription factor., Introduction Lung tumor growth and metastasis requires angiogenesis--the formation of new blood vessels (1, 2). Angiogenesis is typically triggered by hypoxia, which stabilizes hypoxia-inducible transcription factors (HIFs) including HIF1[alpha] and [...]

Humans with obesity differ in their susceptibility to developing insulin resistance and type 2 diabetes (T2D). This variation may relate to the extent of adipose tissue (AT) inflammation that develops as their obesity progresses. The state of macrophage activation has a central role in determining the degree of AT inflammation and thus its dysfunction, and these states are driven by epigenomic alterations linked to gene expression. The underlying mechanisms that regulate these alterations, however, are poorly defined. Here we demonstrate that a co-repressor complex containing G protein pathway suppressor 2 (GPS2) crucially controls the macrophage epigenome during activation by metabolic stress. The study of AT from humans with and without obesity revealed correlations between reduced GPS2 expression in macrophages, elevated systemic and AT inflammation, and diabetic status. The causality of this relationship was confirmed by using macrophage-specific Gps2-knockout (KO) mice, in which inappropriate co-repressor complex function caused enhancer activation, pro-inflammatory gene expression and hypersensitivity toward metabolic-stress signals. By contrast, transplantation of GPS2-overexpressing bone marrow into two mouse models of obesity (ob/ob and diet-induced obesity) reduced inflammation and improved insulin sensitivity. Thus, our data reveal a potentially reversible disease mechanism that links co-repressor-dependent epigenomic alterations in macrophages to AT inflammation and the development of T2D., Macrophages have a central role in innate immunity, but they also play a part in the coordination of metabolic inflammation linked to metabolic diseases, including obesity and T2D (1,2). As [...]

Low-grade chronic inflammation is a major characteristic of obesity and results from deregulated white adipose tissue function. Consequently, there is interest in identifying the underlying regulatory mechanisms and components that [...]

Coordinated regulation of bile acid biosynthesis, the predominant pathway for hepatic cholesterol catabolism, is mediated by few key nuclear receptors including the orphan receptors liver receptor homolog 1 (LRH-1), hepatocyte nuclear factor 4[alpha] (HNF4[alpha]), small heterodimer partner (SHP), and the bile acid receptor FXR (farnesoid X receptor). Activation of FXR initiates a feedback regulatory loop via induction of SHP, which suppresses LRH-1- and HNF4[alpha]-dependent expression of cholesterol 7[alpha] hydroxylase (CYPTA1) and sterol12[alpha] hydroxylase (CYP8B1), the two major pathway enzymes. Here we dissect the transcriptional network governing bile acid biosynthesis in human liver by identifying GPS2, a stoichiometric subunit of a conserved corepressor complex, as a differential coregulator of CYP7A1 and CYP8B1 expression. Direct interactions of GPS2 with SHP, LRH-1, HNF4[alpha], and FXR indicate alternative coregulator recruitment strategies to cause differential transcriptional outcomes. In addition, species-specific differences in the regulation of bile acid biosynthesis were uncovered by identifying human CYP8B1 as a direct FXR target gene, which has implications for therapeutic approaches in bile acid-related human disorders. cholesterol 7[alpha] hydroxylase | sterol 12[alpha] hydroxylase | farnesoid X receptor | small heterodimer partner

Recent studies have identified a series of estrogen receptor (ER)-interacting peptides that recognize sites that are distinct from the classic coregulator recruitment (AF2) region. Here, we report the structural and functional characterization of an ER[alpha]-specific peptide that binds to the liganded receptor in an AF2-independent manner. The 2-[Angstrom] crystal structure of the ER/peptide complex reveals a binding site that is centered on a shallow depression on the [beta]-hairpin face of the ligand-binding domain. The peptide binds in an unusual extended conformation and makes multiple contacts with the ligand-binding domain. The location and architecture of the binding site provides an insight into the peptide's ER subtype specificity and ligand interaction preferences, In vivo, an engineered coactivator containing the peptide motif is able to strongly enhance the transcriptional activity of liganded ER[alpha], particularly in the presence of 4-hydroxytamoxifen. Furthermore, disruption of this binding surface alters ER's response to the coregulator TIF2. Together, these results indicate that this previously unknown interaction site represents a bona fide control surface involved in regulating receptor activity. coregulator | phage display | structure

Molecular dynamics simulations were used to study the impact of the newly modified X-ray ligand, liver receptor homologue 1 (LRH-1 (NR5A2)) to phosphatidylserine, on the receptor and the interaction with different cofactor peptides. The diverse ligand binding response of the cofactor provides a new pathway for drug design to create agonist ligands to modify cofactor interaction.

New insights into estrogen receptors on estrogen as a morphogen and molecular mechanisms of anti-estrogen signaling are focused. It is observed that the multifaceted estrogen receptor signaling is important from both a preclinical and a clinical perspective.

I. INTRODUCTION II. ESTROGEN RECEPTOR TYPES α AND β STRUCTURE AND FUNCTIONAL DOMAINS More than 30 years ago Jensen and Jacobsen [156] came to the conclusion, based on the specific [...]