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 × 10⁶ MSCs/rat (i.p., 2 h after CLP surgery); the MSC-CM rats received the conditioned medium (CM) from 1 × 10⁶ 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/Bcl₂ 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，我们假设败血症诱导会损害大鼠的记忆恢复，而移植的间充质干细胞（MSCs）和MSC条件培养基（MSC-CM）的应用能够减轻这些并发症。从大鼠的脂肪组织和第二次培养传代中获得了MSC。收集了MSC和MSC-CM。将大鼠随机分为四个实验组：假手术，CLP，MSC和MSC-CM。通过盲肠结扎和穿刺（CLP）模型在CLP，MSC和MSC-CM组中诱发败血症。MSC组接受1×10 ⁶ MSCs /大鼠（CLP手术后2 h ip）；MSC-CM大鼠接受1×10 ⁶的条件培养基（CM）败血症诱导后2小时腹膜内的MSC。治疗后24小时进行新的物体识别测试，败血症评分和血压测量。取右海马用于蛋白质印迹分析。CLP大鼠表现出明显更高的败血症评分和收缩压。与假手术组相比，它们的磷酸化形式的CAMKII-α也明显增加，裂解的半胱天冬酶3和Bax / Bcl2比率显着增加，海马组织样品中的c-fos蛋白减少。与CLP大鼠相比，MSC移植和MSC-CM给药显着降低了败血症的平均评分，并防止了败血症引起的血压下降。MSC和MSC-CM组的动物表现出更好的记忆恢复能力，以CAMKII-α磷酸化形式，裂解的caspase 3和Bax / Bcl减弱与CLP组相比，c-fos蛋白表达增加_2个比率，并且c-fos蛋白表达增加。似乎CAMKII和c-fos反过来参与海马的记忆过程的调节。CaMKII-α的过磷酸化形式可能会损害物体识别的能力。我们的研究结果证实，与移植的MSC相比，MSC-CM的应用具有更多的优势，并且可以作为炎症性疾病（如严重脓毒症）的有希望的疗法。