A novelTRAF3IP2variant causing familial scarring alopecia with mixed features of discoid lupus erythematosus and folliculitis decalvans
CLINICAL GENETICS
Authors: Nemer, Georges; El-Hachem, Nehme; Eid, Edward; Hamie, Lamiaa; Bardawil, Tara; Khalil, Samar; El-Rassy, Inaam; Safi, Remi; Khalil, Athar; Abbas, Ossama; Shimomura, Yutaka; Kurban, Mazen
Abstract
Discoid lupus erythematosus (DLE) is an autoimmune disorder with a poorly defined etiology. Despite epidemiologic gender and ethnic biases, a clear genetic basis for DLE remains elusive. In this study, we used exome and RNA sequencing technologies to characterize a consanguineous Lebanese family with four affected individuals who presented with classical scalp DLE and generalized folliculitis. Our results unraveled a novel biallelic variant c.1313C > A leading to a missense substitution p.(Thr438Asn) inTRAF3IP2(NM_147200.3). Expression studies in cultured cells revealed mis-localization of the mutated protein. Functional characterization of the mutated protein showed significant reduction in the physical interaction with the interleukin 17-A receptor (IL17RA), while interaction with TRAF6 was unaffected. By conducting a differential genome-wide transcriptomics analysis between affected and non-affected individuals, we showed that the hair follicle differentiation pathway is drastically suppressed, whereas cytokine and inflammation responses are significantly upregulated. Furthermore, our results were highly concordant with molecular signatures in patients with DLE from a public dataset. In conclusion, this is the first report on a new putative role forTRAF3IP2in the etiology of DLE. The identified molecular features associated with this gene could pave the way for better DLE-targeted treatment.
MicroRNA-31 Reduces Inflammatory Signaling and Promotes Regeneration in Colon Epithelium, and Delivery of Mimics in Microspheres Reduces Colitis in Mice
GASTROENTEROLOGY
Authors: Tian, Yuhua; Xu, Jiuzhi; Li, Yuan; Zhao, Ran; Du, Sujuan; Lv, Cong; Wu, Wei; Liu, Ruiqi; Sheng, Xiaole; Song, Yongli; Bi, Xueyun; Li, Guilin; Li, Mengzhen; Wu, Xi; Lou, Pengbo; You, Huiwen; Cui, Wei; Sun, Jinyue; Shuai, Jianwei; Ren, Fazheng; Zhang, Bing; Guo, Mingzhou; Hou, Xiaohua; Wu, Kaichun; Xue, Lixiang; Zhang, Hongquan; Plikus, Maksim V.; Cong, Yingzi; Lengner, Christopher J.; Liu, Zhanju; Yu, Zhengquan
Abstract
BACKGROUND & AIMS: Levels of microRNA 31 (MIR31) are increased in intestinal tissues from patients with inflammatory bowel diseases and colitis-associated neoplasias. We investigated the effects of this microRNA on intestinal inflammation by studying mice with colitis. METHODS: We obtained colon biopsy samples from 82 patients with ulcerative colitis (UC), 79 patients with Crohn's disease (CD), and 34 healthy individuals (controls) at Shanghai Tenth People's Hospital. MIR31-knockout mice and mice with conditional disruption of Mir31 specifically in the intestinal epithelium (MIR31 conditional knockouts) were given dextran sulfate sodium (DSS) or 2,4,6-trinitrobenzene sulfonic acid (TNBS) to induce colitis. We performed chromatin immunoprecipitation and luciferase assays to study proteins that regulate expression of MIR31, including STAT3 and p65, in LOVO colorectal cancer cells and organoids derived from mouse colon cells. Partially hydrolyzed alpha-lactalbumin was used to generate peptosome nano-particles, and MIR31 mimics were loaded onto their surface using electrostatic adsorption. Peptosome-MIR31 mimic particles were encapsulated into oxidized konjac glucomannan (OKGM) microspheres, which were administered by enema into the large intestines of mice with DSS-induced colitis. Intestinal tissues were collected and analyzed by histology and immunohistochemistry. RESULTS: Levels of MIR31 were increased in inflamed mucosa from patients with CD or UC, and from mice with colitis, compared with controls. STAT3 and nuclear factor-kappa B activated transcription of MIR31 in colorectal cancer cells and organoids in response to tumor necrosis factor and interleukin (IL) 6. MIR31-knockout and conditional-knockout mice developed more severe colitis in response to DSS and TNBS, with increased immune responses, compared with control mice. MIR31 bound to 3' untranslated regions of Il17ra and Il7r messenger RNAs (RNAs) (which encode receptors for the inflammatory cytokines IL17 and IL7) and Il6st mRNA (which encodes GP130, a cytokine signaling protein). These mRNAs and proteins were greater in MIR31-knockout mice with colitis, compared with control mice; MIR31 and MIR31 mimics inhibited their expression. MIR31 also promoted epithelial regeneration by regulating the WNT and Hippo signaling pathways. OKGM peptosome-MIR31 mimic microspheres localized to colonic epithelial cells in mice with colitis; they reduced the inflammatory response, increased body weight and colon length, and promoted epithelial cell proliferation. CONCLUSIONS: MIR31, increased in colon tissues from patients with CD or UC, reduces the inflammatory response in colon epithelium of mice by preventing expression of inflammatory cytokine receptors (Il7R and Il17RA) and signaling proteins (GP130). MIR31 also regulates the WNT and Hippo signaling pathways to promote epithelial regeneration following injury. OKGM peptosome-MIR31 microspheres localize to the colon epithelium of mice to reduce features of colitis. Transcript Profiling: GSE123556