Laboratory of bioengineering and regenerative medicine, Center for Life Sciences, National Laboratory Astana, Nazarbayev University, 53 Kabanbay Batyr Ave, Astana, Kazakhstan, Z05H0P9.
Division of Cancer and Genetics, Cardiff University School of Medicine, Heath Park, Cardiff, CF14 4XN, UK.
Biogerontology. 2018 Jul;19(3-4):287-301. doi: 10.1007/s10522-018-9757-5. Epub 2018 May 26.
Mesenchymal stem cells (MSCs) represent a promising cell source for cellular therapy and tissue engineering and are currently being tested in a number of clinical trials for various diseases. However, like other somatic cells, MSCs age, and this senescence is accompanied by a progressive decline in stem cell function. Several lines of evidence suggest a role for the Rho family GTPase Cdc42 activity in cellular senescence processes. In the present study, we have examined aging-associated Cdc42 activity in rat adipose-derived mesenchymal stem cells (ADMSCs) and the consequences of pharmacological inhibition of Cdc42 in ADMSCs from aged rats. We demonstrate that ADMSCs show a decreased rate of cell growth and a decreased ability to differentiate into chrodrogenic, osteogenic and adipogenic cell lineages as a function of rat age. This is accompanied with an increased staining for SA-β-Gal activity and increased levels of Cdc42 bound to GTP. Treatment of ADMSCs from 24-month old rats with three Cdc42 inhibitors significantly increased proliferation rates, decreased SA-β-Gal staining, and reduced Cdc42-GTP. The Cdc42 inhibitor CASIN increased adipogenic and osteogenic differentiation potential in ADMSCs from 24-month old rats, and decreased the levels of radical oxygen species (ROS), p16 levels, F-actin, and the activity of the ERK1/2 and JNK signaling pathways that were all elevated in these cells. These data suggest that ADMSCs show increased rates of senescence as rats age that appear to be due to elevated Cdc42 activity. Thus, Cdc42 plays important roles in MSC senescence and differentiation potential, and pharmacological reduction of Cdc42 activity can, at least partially, rejuvenate aged MSCs.
间充质干细胞（MSCs）是细胞治疗和组织工程有前途的细胞来源，目前正在多项临床试验中针对各种疾病进行测试。然而，与其他体细胞一样，MSCs 会衰老，这种衰老伴随着干细胞功能的逐渐下降。有几条证据表明 Rho 家族 GTPase Cdc42 的活性在细胞衰老过程中起作用。在本研究中，我们研究了与衰老相关的 Cdc42 活性在大鼠脂肪来源间充质干细胞（ADMSCs）中的作用，以及药理学抑制老年大鼠 ADMSCs 中的 Cdc42 的后果。我们证明 ADMSCs 的细胞生长速度降低，并且向软骨细胞、成骨细胞和脂肪细胞谱系分化的能力随着大鼠年龄的增加而降低。这伴随着 SA-β-Gal 活性染色增加和与 GTP 结合的 Cdc42 水平增加。用三种 Cdc42 抑制剂处理来自 24 月龄大鼠的 ADMSCs 显著增加了增殖率，降低了 SA-β-Gal 染色，并减少了 Cdc42-GTP。Cdc42 抑制剂 CASIN 增加了来自 24 月龄大鼠的 ADMSCs 的成脂和成骨分化潜能，并降低了这些细胞中升高的活性氧（ROS）、p16 水平、F-肌动蛋白和 ERK1/2 和 JNK 信号通路的活性。这些数据表明，随着大鼠年龄的增长，ADMSCs 的衰老速度加快，这似乎是由于 Cdc42 活性升高所致。因此，Cdc42 在 MSC 衰老和分化潜能中发挥重要作用，药理学降低 Cdc42 活性至少可以部分恢复老年 MSCs。
