title: Vitamin D/VDR signaling pathway ameliorates 2,4,6-trinitrobenzene sulfonic acid-induced colitis by inhibiting intestinal epithelial apoptosis.
abstract: Increasing epidemiological data have suggested a link between vitamin D deficiency and the incidence of inflammatory bowel disease (IBD). In the present study, we confirmed that vitamin D deficiency, as well as the decreased local expression of vitamin D receptor (VDR), was prevalent in an IBD cohort. The excessive apoptosis of intestinal epithelial cells (IECs) partly accounts for the development of colonic inflammation and eventually results in IBD. Based on the established inhibitory effects of the vitamin D/VDR pathway on IEC apoptosis, we treated mice with 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis with paricalcitol, a vitamin D analog, in order to investigate the mechanisms responsible for the inhibitory effects of the vitamin D/VDR pathway. We observed that following treatment with vitamin D, the mice presented with only minor bodyweight loss, and the mice also showed improved histological scores and decreased intestinal epithelial permeability compared with the vehicle-treated group. The colonic mRNA expression of inflammatory cytokines and chemokines was markedly suppressed, indicating less severe colitis in the vitamin D-treated mice. Subsequently, we investigated p53 upregulated modulator of apoptosis (PUMA) and p53, two major independent pathways of apoptosis, as well as caspase-3. We found that the vitamin D-treated mice had lower expression levels of caspase-3 than the vehicle-treated mice. PUMA expression showed the same tendency; however, the p53 protein level was not altered. The present study indicates that vitamin D attenuates the development of TNBS-induced colitis by inhibiting the apoptosis of IECs. The mechanisms involved include the downregulation of PUMA expression. Our data provide experimental support for the clinical trials of vitamin D intervention in patients with IBD.
authors: Department of Pediatric Orthopedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors: Tong
authors: T
authors: Zhu
authors: Department of Pediatric Orthopedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors: Tian-Jing
authors: TJ
authors: Liu
authors: Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors: Yong-Yan
authors: YY
authors: Shi
authors: Department of Pediatric Orthopedics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China.
authors: Qun
authors: Q
authors: Zhao
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D016022:Case-Control Studies; D003092:Colitis / Q000139:chemically induced / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D015212:Inflammatory Bowel Diseases / Q000378:metabolism / Q000473:pathology; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051379:Mice; D010539:Permeability / Q000187:drug effects; D018167:Receptors, Calcitriol / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D014302:Trinitrobenzenesulfonic Acid / Q000009:adverse effects; D014807:Vitamin D / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D018167:Receptors, Calcitriol; D014807:Vitamin D; D014302:Trinitrobenzenesulfonic Acid