Department of Urology, China-Japan Union Hospital of Jilin University, Changchun, P. R. China.
FASEB J. 2020 Oct;34(10):13345-13360. doi: 10.1096/fj.202000102RR. Epub 2020 Aug 17.
Erectile dysfunction (ED) is a common comorbidity in males with diabetes mellitus (DM), whose pathogenesis might be induced by dysregulation of corpus cavernosum smooth muscle cells (CCSMCs). Gene Expression Omnibus repository-based analysis identified the differentially expressed PDCD4 in DM rats. PDCD4 has also been determined as a putative gene under the regulatory control of microRNA-21-5p (miR-21-5p). This study aimed to further determine the functional role of miR-21-5p in CCSMCs in a rat model of diabetes mellitus-induced erectile dysfunction (DMED). CCSMCs were isolated from penile cavernous tissue and cultured in high glucose (HG) medium. The expression of miR-21-5p and/or PDCD4 was altered in CCSMCs, as directly or indirectly measured by CCK-8 assay, flow cytometry, and TUNEL assays. Furthermore, exosomes were isolated from mesenchymal stem cells (MSCs) transfected with miR-21-5p mimic or miR-21-5p inhibitor and co-cultured with CCSMCs. DMED rats were injected with lentivirus carrying PDCD4/siRNA-PDCD4 plasmids, or exosomes from MSCs containing miR-21-5p-agomir to explore their roles in vivo. The experimental data validated that PDCD4 was upregulated in cavernous tissue of DMED rats. miR-21-5p targeted and inhibited PDCD4. miR-21-5p was enriched in MSC-exosomes. Moreover, PDCD4 downregulation, miR-21-5p elevation or MSC-derived exosomal miR-21-5p reduced apoptosis and enhanced proliferation of CCSMCs cultured in HG medium. PDCD4 silencing or miR-21-5p-containing MSC-exosomes improved erectile function and smooth muscle density in DMED rats. Collectively, our findings suggested that MSC-derived exosomal miR-21-5p suppressed PDCD4 expression and ED in rats with DM.
勃起功能障碍（ED）是糖尿病（DM）男性的常见合并症，其发病机制可能是由海绵体平滑肌细胞（CCSMCs）的失调引起的。基于基因表达综合数据库的分析确定了糖尿病大鼠中差异表达的 PDCD4。PDCD4 也被确定为 microRNA-21-5p（miR-21-5p）调控下的假定基因。本研究旨在进一步确定 miR-21-5p 在糖尿病诱导的勃起功能障碍（DMED）大鼠模型中海马体平滑肌细胞中的功能作用。从阴茎海绵体组织中分离出 CCSMCs，并在高糖（HG）培养基中培养。通过 CCK-8 测定、流式细胞术和 TUNEL 测定等直接或间接方法改变 CCSMCs 中 miR-21-5p 和/或 PDCD4 的表达。此外，从转染 miR-21-5p 模拟物或 miR-21-5p 抑制剂的间充质干细胞（MSCs）中分离出外泌体，并与 CCSMCs 共培养。DMED 大鼠注射携带 PDCD4/siRNA-PDCD4 质粒的慢病毒或含有 miR-21-5p-agonist 的 MSC 来源的外泌体，以探索它们在体内的作用。实验数据验证了 PDCD4 在 DMED 大鼠海绵组织中上调。miR-21-5p 靶向并抑制 PDCD4。miR-21-5p 在 MSC 外泌体中富集。此外，CCSMCs 在 HG 培养基中培养时，下调 PDCD4、上调 miR-21-5p 或 MSC 衍生的外泌体 miR-21-5p 均可减少细胞凋亡并增强细胞增殖。沉默 PDCD4 或含有 miR-21-5p 的 MSC 来源的外泌体可改善 DMED 大鼠的勃起功能和平滑肌密度。综上所述，我们的研究结果表明，MSC 来源的外泌体 miR-21-5p 抑制 DM 大鼠的 PDCD4 表达和 ED。
