Department of Internal Medicine, Division of Nephrology and Hypertension, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
Stem Cell Rev Rep. 2020 Oct;16(5):933-945. doi: 10.1007/s12015-020-09988-3.
Transplantation of autologous mesenchymal stem cells (MSCs) is an effective therapy for several diseases. Mitochondria modulate several important aspects of MSC function, but might be damaged by comorbidities and cardiovascular risk factors. We hypothesized that metabolic syndrome (MetS) compromises 3D mitochondrial structure, dynamics, and function in swine adipose tissue-derived MSCs. Domestic pigs were fed a Lean or MetS diet (n = 6 each) for 16 weeks. MSCs were collected from subcutaneous abdominal fat and their mitochondria analyzed using state-of-the-art Serial Block Face Electron Microscopy and 3D reconstruction. Mitochondrial dynamics (fusion/fission) were assessed by mRNA sequencing and Western blotting, and bioenergetics by membrane potential (TMRE), cytochrome-c oxidase (COX)-IV activity, and Seahorse Analyzer. Expression of mitochondria-associated microRNAs (mitomiRs) was measured by quantitative polymerase chain reaction (qPCR). MetS pigs developed obesity, hypertension, insulin resistance, and hyperlipidemia. Mitochondrial density was similar between the groups, but 3D mitochondrial and matrix volumes were lower in MetS-MSCs versus Lean-MSCs. Mitochondrial fission was higher, but fusion lower in MetS-MSCs versus Lean-MSCs, as were membrane potential, COX-IV activity, and ATP production. Contrarily, expression of the mitomiRs miR15a, miR-137, and miR-181c, which target mitochondrial genes that support mitochondrial structure, energy pathways, and dynamics, was higher in MetS-MSCs compared to Lean-MSCs, suggesting a potential to modulate their expression. MetS damages MSC 3D mitochondrial structure, dynamics, and function, and may modulate genes encoding for mitochondrial proteins. These observations support development of mitoprotective strategies to preserve the regenerative potency of MSCs and their suitability for autologous transplantation in patients with MetS.
自体间充质干细胞 (MSCs) 移植是几种疾病的有效治疗方法。线粒体调节 MSC 功能的几个重要方面，但可能会被合并症和心血管危险因素损害。我们假设代谢综合征 (MetS) 会损害猪脂肪组织来源的 MSC 的 3D 线粒体结构、动力学和功能。家猪喂食瘦素或 MetS 饮食（每组 6 只）16 周。从皮下腹部脂肪中收集 MSCs，并使用最先进的串行块面电子显微镜和 3D 重建分析其线粒体。通过 mRNA 测序和 Western blot 评估线粒体动力学（融合/裂变），通过膜电位 (TMRE)、细胞色素-c 氧化酶 (COX)-IV 活性和 Seahorse 分析仪评估生物能学。通过定量聚合酶链反应 (qPCR) 测量线粒体相关 microRNA (mitomiRs) 的表达。MetS 猪发展为肥胖、高血压、胰岛素抵抗和高脂血症。线粒体密度在两组之间相似，但 MetS-MSCs 中的 3D 线粒体和基质体积低于 Lean-MSCs。MetS-MSCs 中的线粒体裂变更高，但融合更低，膜电位、COX-IV 活性和 ATP 产生也更低。相反，靶向支持线粒体结构、能量途径和动力学的线粒体基因的 mitomiRs miR15a、miR-137 和 miR-181c 的表达在 MetS-MSCs 中高于 Lean-MSCs，这表明它们的表达可能受到调节。MetS 损害 MSC 的 3D 线粒体结构、动力学和功能，并可能调节编码线粒体蛋白的基因。这些观察结果支持开发 mitoprotective 策略来维持 MSC 的再生能力及其在 MetS 患者中自体移植的适用性。
