Skin Biology Laboratory, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
J Cell Physiol. 2022 Feb;237(2):1429-1439. doi: 10.1002/jcp.30614. Epub 2021 Oct 22.
The loss of melanocytes in vitiligo is associated with architectural, transcriptional, and cellular perturbations of keratinocytes and manifests as a reduced proliferation potential in vitro and delayed re-epithelialization in vivo. To understand the molecular mechanisms underlying this delay, microRNA (miRNA) profiling was performed on split skin biopsies collected on Day 1 (basal level) and Day 14 (wound re-epithelialization) from nonlesional (NL) and lesional (L) skin of five subjects with stable nonsegmental vitiligo and 129 miRNAs were found to be differentially regulated between the NL and L healed epidermis. miR-21-5p, expressed at comparable levels on NL and L Day 1 samples, demonstrated significant upregulation during re-epithelialization. However, the extent of its upregulation was relatively lower in L (10 times compared to Day 1) as compared to NL skin (17 times compared to Day 1). The overexpression of miR-21 in keratinocytes led to a significant increase in the expression of proliferation markers (Ki67 and MCM6 messenger RNA, Ki67 positivity), along with an increase in keratinocyte migration. Using a small interfering RNA mediated knockdown approach, we further demonstrated that miR-21-5p mediates its effects by suppressing the expression of programmed cell death 4 (PDCD4) and mammary serine protease inhibitor (Maspin), both tumor-suppressor genes. Investigation of clinical samples corroborated the lower miR-21 levels and a higher expression of PDCD4 and Maspin in L Day 14 compared to the NL Day 14 epidermis. In conclusion, this study revealed that a relatively lower upregulation of miR-21-5p in L skin leads to significantly higher levels of PDCD4 and Maspin, delaying wound re-epithelialization by reducing the proliferation and migration of keratinocytes.
白癜风患者黑素细胞的丢失与角质形成细胞的结构、转录和细胞扰动有关,表现为体外增殖潜力降低和体内再上皮化延迟。为了了解这种延迟的分子机制,对来自 5 名稳定非节段性白癜风患者的非病变(NL)和病变(L)皮肤的第 1 天(基础水平)和第 14 天(伤口再上皮化)的分裂皮肤活检进行了 microRNA(miRNA)谱分析,发现 129 种 miRNA 在 NL 和 L 愈合表皮之间存在差异调节。miR-21-5p 在 NL 和 L 第 1 天样本中的表达水平相当,在再上皮化过程中表现出显著上调。然而,与 NL 皮肤相比(与第 1 天相比增加 17 倍),L 皮肤(与第 1 天相比增加 10 倍)的上调程度相对较低。miR-21 在角质形成细胞中的过表达导致增殖标志物(Ki67 和 MCM6 信使 RNA,Ki67 阳性)的表达显著增加,同时角质形成细胞迁移增加。使用小干扰 RNA 介导的敲低方法,我们进一步证明 miR-21-5p 通过抑制程序性细胞死亡 4(PDCD4)和乳腺丝氨酸蛋白酶抑制剂(Maspin)的表达来发挥其作用,这两种基因都是肿瘤抑制基因。对临床样本的研究证实,与 NL 第 14 天相比,L 第 14 天的 miR-21 水平较低,PDCD4 和 Maspin 的表达较高。总之,这项研究表明,L 皮肤中 miR-21-5p 的相对较低上调导致 PDCD4 和 Maspin 的水平显著升高,通过降低角质形成细胞的增殖和迁移,延迟伤口再上皮化。