Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism, The Second Affiliated Hospital of Harbin Medical University, 148 Baojian Road, Harbin, 150086, People's Republic of China.
Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, 148 Baojian Road, Harbin, 150086, People's Republic of China.
Stem Cell Res Ther. 2017 Oct 10;8(1):224. doi: 10.1186/s13287-017-0676-1.
Mesenchymal stem cells (MSCs) are emerging as an extremely promising therapeutic agent for tissue repair. However, limitations exist such as the low numbers of MSCs obtained from donors, and the poor survival and function of donor cells. Omentin-1, a new fat depot-specific secretory adipokine, exerts proproliferation, prosurvival, and proangiogenic functions in certain cells via an Akt-dependent mechanism; however, little is known about the influence of omentin-1 on MSCs.
MSCs were isolated from 60-80 g donor rats. Cell proliferation was assessed with CCK-8 and EdU assay. Cell cycle, apoptosis ratio, reactive oxygen species concentration, and mitochondrial membrane potential were detected by flow cytometry. Hoechst 33342 dye was used to assess morphological changes of apoptosis. Expression levels of Akt, FoxO3a, GSK-3β, and apoptosis- and cell cycle-associated proteins were detected by Western blotting. Tube formation assay was used to test the angiogenesis role of conditioned medium from MSCs in vitro. The cytokine secretion was assessed by ELISA.
After treatment with omentin-1 (100-800 ng/ml), MSCs displayed a higher proliferative capacity with an increasing number of cells in the S and G2 phase of the cell cycle. Moreover, omentin-1 preconditioning for 1 h could protect MSCs against HO-induced apoptosis in a concentration-dependent manner. Furthermore, omentin-1 pretreatment reduced the excessive reactive oxygen species. Western blots revealed that increased Bcl-2 and decreased Bax appeared in MSCs after omentin-1 incubation, which inhibited the mitochondrial apoptosis pathways with evidence showing inhibition of caspase-3 cleavage and preservation of mitochondrial membrane potential. Omentin-1 could enhance angiogenic growth factor secretion and elevate the ability of MSCs to stimulate tube formation by human umbilical vein endothelial cells (HUVECs). Furthermore, omentin-1 enhanced Akt phosphorylation; however, blockade of the PI3K/Akt pathway with an inhibitor, LY294002 (20 μM), suppressed the above beneficial effects of omentin-1.
Omentin-1 can exert beneficial effects on MSCs by promoting proliferation, inhibiting apoptosis, increasing secretion of angiogenic cytokines, and enhancing the ability for stimulating tube formation by HUVECs via the PI3K/Akt signaling pathway. Thus, omentin-1 may be considered a candidate for optimizing MSC-based cell therapy.
间充质干细胞（MSCs）作为组织修复的一种极有前途的治疗剂正在兴起。然而，从供体中获得的 MSC 数量较少、供体细胞的存活和功能较差等限制仍然存在。网膜素-1 是一种新的脂肪组织特异性分泌脂肪因子，通过 Akt 依赖性机制在某些细胞中发挥促增殖、抗凋亡和促血管生成作用;然而，关于网膜素-1 对 MSCs 的影响知之甚少。
从 60-80g 的供体大鼠中分离 MSC。用 CCK-8 和 EdU 检测细胞增殖。通过流式细胞术检测细胞周期、细胞凋亡率、活性氧浓度和线粒体膜电位。Hoechst 33342 染色用于评估凋亡的形态变化。用 Western blot 检测 Akt、FoxO3a、GSK-3β 和凋亡及细胞周期相关蛋白的表达水平。体外通过 MSC 条件培养基的管形成试验检测血管生成作用。ELISA 检测细胞因子分泌情况。
用网膜素-1（100-800ng/ml）处理后，MSC 细胞周期中 S 和 G2 期的细胞数量增加，增殖能力增强。此外，1h 的网膜素-1 预处理可浓度依赖性地保护 MSC 免受 HO 诱导的凋亡。此外，网膜素-1 预处理可减少过多的活性氧。Western blot 显示，网膜素-1 孵育后 MSC 中 Bcl-2 增加，Bax 减少，抑制线粒体凋亡途径，证据表明抑制 caspase-3 切割和保持线粒体膜电位。网膜素-1 可增强血管生成生长因子的分泌，并提高 MSC 刺激人脐静脉内皮细胞（HUVEC）管形成的能力。此外，网膜素-1 增强了 Akt 的磷酸化;然而，用抑制剂 LY294002（20μM）阻断 PI3K/Akt 通路抑制了网膜素-1 的上述有益作用。
网膜素-1 通过促进增殖、抑制凋亡、增加血管生成细胞因子的分泌以及增强 HUVEC 管形成能力，对 MSC 发挥有益作用，通过 PI3K/Akt 信号通路。因此，网膜素-1 可以被认为是优化基于 MSC 的细胞治疗的候选药物。
