Biology subjects

Huang, W. J. M.

Publications and source records attributed to Huang, W. J. M..

4 recordsLinked to original sources

bioRxiv2022

Chromatin-associated lncRNA Malat1 regulates Th17 effector program and promotes intestinal inflammation

Interleukin IL-17 cytokines are central regulators of mucosal homeostasis and disease. In mouse models of colonic tissue injury, IL-17A promotes epithelial barrier functions and restricts local inflammation. Here, we report that IL-17A production by the diverse T lymphocyte subsets is dynamically regulated at different stages of colitis pathogenesis. During the onset and peak of the disease, T{gamma}{delta}17 cells are the major IL-17A producers, while Th17 activity is temporally restricted by long non-coding RNA (lncRNA) Malat1. In response to IL-6 and TGF{beta} signaling, Malat1 is recruited to the Th17-specific cis-regulatory elements, CNS3 and CNS4, of the Il17a locus to fine-tune bivalent super-enhancer activities and repress local transcription. During the resolution phase of inflammation, Malat1 expression is down-regulated to enhance Th17 activities, allowing Th17 cells to emerge as the main producers of IL-17A in the colonic lamina propria. Genetic ablation of Malat1 potentiates IL-17A production in Th17 cells and improves disease outcomes in mouse models of colitis. These findings uncover a surprising role of a chromatin-associated lncRNA in regulating colonic Th17-specific responses to control the timing of inflammation resolution. Significance StatementT cells are critical modulators of mucosal barrier function and inflammation. The function of long-noncoding RNAs (lncRNAs) in T cells and their role in mucosal inflammation remain elusive. Here, we identify an essential role of the lncRNA Malat1 restricting transcription of the Il17a locus in Th17 cells encoding a cytokine implicated in epithelial barrier function post-injury. By controlling the activity of the bivalent super-enhancer at the Il17a locus, Malat1 regulates the timing of inflammation resolution in the intestine. The Malat1-Il17a pathway reveals new targets for combating mucosal diseases. Graphic Abstract O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

immunology↗

bioRxiv2021

Serine 182 on RORγt regulates T helper 17 and regulatory T cell functions to resolve inflammation

Intestine homeostasis is maintained by the delicate balance of Th17 effector cells and Treg cells. Dysregulation of these cell populations contributes to inflammation, tissue damage, and chronic conditions. ROR{gamma}t is essential for the differentiation of Th17 and a subset of Treg (ROR{gamma}t+ Treg) cells involved in intestinal inflammation. ROR{gamma}t belongs to the nuclear receptor family of transcription factors with hinge regions that are highly flexible for co-activator/co-repressor interactions. Serine 182 at the hinge region of ROR{gamma}t is phosphorylated. This study aims to uncover how S182 on ROR{gamma}t contributes to mucosal homeostasis and diseases. We used CRISRP technology to generate a phosphor-null knock-in mutant mouse line (ROR{gamma}tS182A) to assess its role in intestine physiology. scRNA-seq was performed on WT and ROR{gamma}tS182A cohoused littermates to evaluate colonic T cell heterogeneity under steady state and colitis settings. Single-cell transcriptomics revealed that ROR{gamma}tS182 maintains colonic T cell heterogeneity under steady state, without interfering T cell development and differentiation. In inflamed tissues, ROR{gamma}tS182 simultaneously restricts IL-1{beta}-mediated Th17 activities and promotes anti-inflammatory cytokine IL-10 production in LT-like Treg cells. Phospho-null ROR{gamma}tS182A knock-in mice challenged with DSS induced colitis and EAE experienced delayed recovery and exacerbated pathology. The double switch role of ROR{gamma}tS182 is critical in resolving T cell-mediated inflammation and provides a potential therapeutic target to combat autoimmune diseases.

immunology↗

bioRxiv2020

RNA adenosine deaminase ADAR2 modulates T helper 17 cell effector function

ADAR1 and ADAR2 catalyze adenosine-to-inosine (A-to-I) editing, the most common post-transcriptional modification in RNA. While ADAR1 is ubiquitously expressed and plays a critical role in preventing activation of the host immune system, ADAR2 exhibits tissue-specific and inducible expression patterns, and its function in the immune system is not known. Here, we identify an intragenic super-enhancer involved in the dramatic induction of ADAR2 when naive helper T cells differentiate toward the Th17 lineage. By editing the inverted repeat sequences at the 3 untranslated region (UTR) of Malt1, which encodes a component of the NF-{kappa}B activation complex, ADAR2 promotes MALT1 expression and Th17 effector function. Interference with the ADAR2-MALT1 pathway dampens the production of Th17 cytokines and promotes T cell-mediated colitis. This study expands our understanding of RNA editing in adaptive immunity and identifies the ADAR2-MALT1-IL-17A axis as a potential therapeutic target for inflammatory conditions in the intestine.

immunology↗

bioRxiv2020

DDX5 targets tissue-specific RNAs to promote intestine tumorigenesis

Tumorigenesis in different segments of the intestinal tract involves tissue-specific oncogenic drivers. In the colon, complement component 3 (C3) activation is a major contributor to inflammation and malignancies. By contrast, tumorigenesis in the small intestine involves fatty acid-binding protein 1 (FABP1). However, little is known of the upstream mechanisms driving their expressions in different segments of the intestinal tract. Here, we report that an RNA binding protein DDX5 augments C3 and FABP1 expressions post-transcriptionally to promote tumorigenesis in the colon and small intestine, respectively. Mice with epithelial-specific knockout of DDX5 are protected from intestine tumorigenesis. The identification of DDX5 as the common upstream regulator of tissue-specific oncogenic molecules provides a new therapeutic target for intestine cancers.

cancer biology↗