Department of Physiology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, 1417613151, Iran.
Department of Immunology, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran.
Mol Neurobiol. 2020 Sep;57(9):3633-3645. doi: 10.1007/s12035-020-01991-6. Epub 2020 Jun 19.
In this study, we hypothesized that sepsis induction impairs memory retrieval in rats while transplanted mesenchymal stem cells (MSCs) and MSC-conditioned medium (MSC-CM) application are capable of attenuating those complications. MSCs were obtained from adipose tissue of rats and at the second culture passage; MSCs and MSC-CM were collected. Rats were randomly divided into four experimental groups: sham, CLP, MSC, and MSC-CM. Sepsis was induced by cecal ligation and puncture (CLP) model in the CLP, MSC, and MSC-CM groups. The MSC group received 1 × 10 MSCs/rat (i.p., 2 h after CLP surgery); the MSC-CM rats received the conditioned medium (CM) from 1 × 10 MSCs intraperitoneally 2 h after sepsis induction. Novel object recognition test, sepsis score, and blood pressure measurement were performed 24 h after the treatments. The right hippocampus was taken for western blot analysis. CLP rats showed a significantly higher sepsis score and systolic blood pressure. They also had a significant increase in the phosphorylated form of CAMKII-α, cleaved caspase 3 and Bax/Bcl2 ratio, and a reduction in c-fos protein in the hippocampus tissue samples compared with the sham group. MSC transplantation and MSC-CM administration significantly decreased the mean sepsis score and prevented sepsis-induced attenuation of blood pressure compared with the CLP rats. Animals in the MSC and MSC-CM groups showed a better memory retrieval, attenuation in phosphorylated form of CAMKII-α, cleaved caspase 3 and Bax/Bcl ratio, and an increase in c-fos protein expression compared with the CLP group. It seems that CAMKII and c-fos are inversely involved in regulating memory processes in hippocampus. Phosphorylated form of CaMKII-α overexpression may impair the ability of object recognition. Our findings confirmed that MSC-CM application has more advantages compared with transplanted MSCs and may be offered as a promising therapy for inflammatory diseases such as severe sepsis.
在这项研究中，我们假设脓毒症诱导会损害大鼠的记忆检索，而移植间充质干细胞（MSCs）和 MSC 条件培养基（MSC-CM）的应用能够减轻这些并发症。MSCs 从大鼠脂肪组织中获得，并在第二培养传代时收集。大鼠随机分为四组：假手术组、CLP 组、MSC 组和 MSC-CM 组。CLP 组、MSC 组和 MSC-CM 组通过盲肠结扎和穿刺（CLP）模型诱导脓毒症。MSC 组在 CLP 手术后 2 小时给予 1×10 MSCs/大鼠（腹腔内）；MSC-CM 组在脓毒症诱导后 2 小时给予来自 1×10 MSCs 的条件培养基（腹腔内）。治疗后 24 小时进行新物体识别试验、脓毒症评分和血压测量。取右侧海马进行 Western blot 分析。CLP 组大鼠的脓毒症评分和收缩压明显升高。与假手术组相比，它们的海马组织样本中 CAMKII-α 磷酸化形式、裂解的 caspase 3 和 Bax/Bcl2 比值明显增加，c-fos 蛋白减少。与 CLP 组相比，MSC 移植和 MSC-CM 给药显著降低了平均脓毒症评分，并预防了脓毒症引起的血压下降。与 CLP 组相比，MSC 和 MSC-CM 组的动物表现出更好的记忆检索、CAMKII-α 磷酸化形式、裂解的 caspase 3 和 Bax/Bcl2 比值降低以及 c-fos 蛋白表达增加。CAMKII 和 c-fos 似乎参与调节海马中的记忆过程。CaMKII-α 的过度磷酸化可能会损害物体识别能力。我们的研究结果证实，与移植的 MSCs 相比，MSC-CM 的应用具有更多优势，可作为严重脓毒症等炎症性疾病的有前途的治疗方法。
