Janjetovic Zorica, Postlethwaite Arnold, Kang Hong Soon, Kim Tae-Kang, Tuckey Robert C, Crossman David K, Qayyum Shariq, Jetten Anton M, Slominski Andrzej T
Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama.
Department of Medicine, University of Tennessee Health Science Center, Veteran Administration Medical Center, Memphis, Tennessee.
Endocrinology. 2021 Jan 1;162(1). doi: 10.1210/endocr/bqaa198.
Previous studies showed that noncalcemic 20(OH)D3, a product of CYP11A1 action on vitamin D3, has antifibrotic activity in human dermal fibroblasts and in a bleomycin mouse model of scleroderma. In this study, we tested the role of retinoic acid-related orphan receptor γ (RORγ), which is expressed in skin, in the action of CYP11A1-derived secosteroids using murine fibroblasts isolated from the skin of wild-type (RORγ +/+), knockout (RORγ -/-), and heterozygote (RORγ +/-) mice. CYP11A1-derived 20(OH)D3, 20,23(OH)2D3, 1,20(OH)2D3, and 1,20,23(OH)3D3 inhibited proliferation of RORγ +/+ fibroblasts in a dose-dependent manner with a similar potency to 1,25(OH)2D3. Surprisingly, this effect was reversed in RORγ +/- and RORγ -/- fibroblasts, with the most pronounced stimulatory effect seen in RORγ -/- fibroblasts. All analogs tested inhibited TGF-β1-induced collagen synthesis in RORγ +/+ fibroblasts and the expression of other fibrosis-related genes. This effect was curtailed or reversed in RORγ -/- fibroblasts. These results show that the antiproliferative and antifibrotic activities of the vitamin D hydroxy derivatives are dependent on a functional RORγ. The dramatic changes in the transcriptomes of fibroblasts of RORγ -/- versus wild-type mice following treatment with 20(OH)D3 or 1,20(OH)2D3 provide a molecular basis to explain, at least in part, the observed phenotypic differences.
先前的研究表明，非钙调的20(OH)D3（CYP11A1作用于维生素D3的产物）在人皮肤成纤维细胞和硬皮病博来霉素小鼠模型中具有抗纤维化活性。在本研究中，我们利用从野生型（RORγ +/+）、基因敲除型（RORγ -/-）和杂合子（RORγ +/-）小鼠皮肤中分离出的鼠成纤维细胞，测试了在皮肤中表达的视黄酸相关孤儿受体γ（RORγ）在CYP11A1衍生的甾醇类化合物作用中的作用。CYP11A1衍生的20(OH)D3、20,23(OH)2D3、1,20(OH)2D3和1,20,23(OH)3D3以剂量依赖的方式抑制RORγ +/+成纤维细胞的增殖，其效力与1,25(OH)2D3相似。令人惊讶的是，这种作用在RORγ +/-和RORγ -/-成纤维细胞中发生了逆转，在RORγ -/-成纤维细胞中观察到最明显的刺激作用。所有测试的类似物均抑制RORγ +/+成纤维细胞中TGF-β1诱导的胶原蛋白合成以及其他纤维化相关基因的表达。这种作用在RORγ -/-成纤维细胞中减弱或逆转。这些结果表明，维生素D羟基衍生物的抗增殖和抗纤维化活性依赖于功能性RORγ。用20(OH)D3或1,20(OH)2D3处理后，RORγ -/-与野生型小鼠成纤维细胞转录组的显著变化至少部分地为解释观察到的表型差异提供了分子基础。
