Suppressive myeloid cells inhibit antitumor immunity by preventing T-cell responses. Immunoglobulin-like transcript 3 (ILT3; also known as LILRB4) is highly expressed on tumor-associated myeloid cells and promotes their suppressive phenotype. However, the ligand that engages ILT3 within the tumor microenvironment and renders tumor-associated myeloid cells suppressive is unknown.
View Article and Find Full Text PDFCancer cachexia is a highly prevalent condition associated with poor quality of life and reduced survival. Tumor-induced perturbations in the endocrine, immune and nervous systems drive anorexia and catabolic changes in adipose tissue and skeletal muscle, hallmarks of cancer cachexia. However, the molecular mechanisms driving cachexia remain poorly defined, and there are currently no approved drugs for the condition.
View Article and Find Full Text PDFUnder homeostatic conditions, animals use well-defined hypothalamic neural circuits to help maintain stable body weight, by integrating metabolic and hormonal signals from the periphery to balance food consumption and energy expenditure. In stressed or disease conditions, however, animals use alternative neuronal pathways to adapt to the metabolic challenges of altered energy demand. Recent studies have identified brain areas outside the hypothalamus that are activated under these 'non-homeostatic' conditions, but the molecular nature of the peripheral signals and brain-localized receptors that activate these circuits remains elusive.
View Article and Find Full Text PDFHepatocellular carcinoma (HCC), one of the leading causes of cancer-related death, develops from premalignant lesions in chronically damaged livers. Although it is well established that FGF19 acts through the receptor complex FGFR4-β-Klotho (KLB) to regulate bile acid metabolism, FGF19 is also implicated in the development of HCC. In humans, FGF19 is amplified in HCC and its expression is induced in the liver under cholestatic and cirrhotic conditions.
View Article and Find Full Text PDFGastrointestinal bypass surgeries that result in rerouting and subsequent exclusion of nutrients from the duodenum appear to rapidly alleviate hyperglycemia and hyperinsulinemia independent of weight loss. While the mechanism(s) responsible for normalization of glucose homeostasis remains to be fully elucidated, this rapid normalization coupled with the well-known effects of vagal inputs into glucose homeostasis suggests a neurohormonally mediated mechanism. Our results show that duodenal bypass surgery on obese, insulin-resistant Zucker fa/fa rats restored insulin sensitivity in both liver and peripheral tissues independent of body weight.
View Article and Find Full Text PDFA large body of literature provides compelling evidence for the role of evolutionarily conserved core histone residues in various biological processes. However, site-directed mutagenesis of individual residues that are known to be sites of posttranslational modifications often does not result in clear phenotypic defects. In some cases, the combination of multiple mutations can give rise to stronger phenotypes, implying functional redundancy between distinct residues on histones.
View Article and Find Full Text PDFThe TCT motif (polypyrimidine initiator) encompasses the transcription start site of nearly all ribosomal protein genes in Drosophila and mammals. The TCT motif is required for transcription of ribosomal protein gene promoters. The TCT element resembles the Inr (initiator), but is not recognized by TFIID and cannot function in lieu of an Inr.
View Article and Find Full Text PDFThe regulation of gene transcription is critical for the proper development and growth of an organism. The transcription of protein-coding genes initiates at the RNA polymerase II core promoter, which is a diverse module that can be controlled by many different elements such as the TATA box and downstream core promoter element (DPE). To understand the basis for core promoter diversity, we explored potential biological functions of the DPE.
View Article and Find Full Text PDFThe RNA polymerase II core promoter is a structurally and functionally diverse transcriptional module. RNAi depletion and overexpression experiments revealed a genetic circuit that controls the balance of transcription from two core promoter motifs, the TATA box and the downstream core promoter element (DPE). In this circuit, TBP activates TATA-dependent transcription and represses DPE-dependent transcription, whereas Mot1 and NC2 block TBP function and thus repress TATA-dependent transcription and activate DPE-dependent transcription.
View Article and Find Full Text PDFThe RNA polymerase II core promoter is generally defined to be the sequence that directs the initiation of transcription. This simple definition belies a diverse and complex transcriptional module. There are two major types of core promoters - focused and dispersed.
View Article and Find Full Text PDFMot1 is an essential Snf2/Swi2-related Saccharomyces cerevisiae protein that binds the TATA-binding protein (TBP) and removes TBP from DNA using ATP hydrolysis. Mot1 functions in vivo both as a repressor and as an activator of transcription. Mot1 catalysis of TBP.
View Article and Find Full Text PDF