Department of Nephrology, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
Department of Stem Cell Biology and Medicine, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
Stem Cell Res Ther. 2023 Nov 22;14(1):337. doi: 10.1186/s13287-023-03553-8.
Contrast-induced nephropathy (CIN) is a major clinical problem associated with acute kidney injury during hospitalization. However, effective treatments for CIN are currently lacking. Mesenchymal stem cells (MSCs) have protective effects against kidney injury by suppressing inflammation and fibrosis. We previously showed that MSCs cultured in serum-free medium (SF-MSCs) enhance their anti-inflammatory and anti-fibrotic effects. However, whether SF-MSCs potentiate their anti-apoptotic effects is unknown. Here, we investigated the effects of SF-MSCs on a CIN mouse model.
To create CIN model mice, we removed right kidney at first. One week later, the left renal artery was clamped for 30 min to cause ischemia-reperfusion injury, and mice were injected with iohexol. Then the kidney received 10 Gy of irradiation, and MSCs or SF-MSCs were injected immediately. At 24 h post-injection, mice were sacrificed, and their blood and kidneys were collected to evaluate renal function, DNA damage, and apoptosis. In addition, apoptosis was induced in HEK-293 cells by irradiation and cells were treated with conditioned medium from MSCs or SF-MSCs.
Treatment of CIN model mice with SF-MSCs markedly improved renal function compared with MSCs treatment. Cleaved caspase-3 levels and TUNEL-positive cell numbers were strongly suppressed in CIN model mice treated with SF-MSCs compared with the findings in those treated with MSCs. γH2AX levels, a chromosome damage marker, were reduced by MSCs and further reduced by SF-MSCs. In addition, cleaved caspase-3 in irradiated HEK-293 cells was more strongly suppressed by conditioned medium from SF-MSCs than by that from MSCs. Secretion of epidermal growth factor (EGF) was enhanced by culturing MSCs in serum-free medium. Knockdown of EGF by siRNA attenuated the inhibitory effects of SF-MSCs on CIN-induced renal dysfunction and tubular apoptosis.
These findings strongly suggest that SF-MSCs improve CIN in model mice by exerting anti-apoptotic effects in a paracrine manner. Thus, SF-MSCs represent a potential novel therapy for CIN.
造影剂肾病（CIN）是住院期间急性肾损伤相关的主要临床问题。然而，目前缺乏有效的 CIN 治疗方法。间充质干细胞（MSCs）通过抑制炎症和纤维化对肾损伤具有保护作用。我们之前的研究表明，在无血清培养基中培养的 MSCs（SF-MSCs）增强了其抗炎和抗纤维化作用。然而，SF-MSCs 是否增强其抗细胞凋亡作用尚不清楚。在此，我们研究了 SF-MSCs 对 CIN 小鼠模型的影响。
为了建立 CIN 模型小鼠，我们首先切除右肾。一周后，夹闭左肾动脉 30 分钟造成缺血再灌注损伤，并给小鼠注射碘海醇。然后对肾脏进行 10Gy 照射，并立即注射 MSCs 或 SF-MSCs。注射后 24 小时，处死小鼠，采集其血液和肾脏，评估肾功能、DNA 损伤和细胞凋亡。此外，通过照射诱导 HEK-293 细胞凋亡，并将条件培养基从 MSCs 或 SF-MSCs 处理细胞。
与 MSC 治疗相比，SF-MSCs 治疗 CIN 模型小鼠可显著改善肾功能。与 MSC 治疗组相比，SF-MSCs 治疗的 CIN 模型小鼠中 cleaved caspase-3 水平和 TUNEL 阳性细胞数量明显降低。γH2AX 水平，一种染色体损伤标志物，被 MSCs 降低，并被 SF-MSCs 进一步降低。此外，SF-MSCs 条件培养基比 MSCs 条件培养基更能抑制照射后的 HEK-293 细胞中的 cleaved caspase-3。在无血清培养基中培养 MSCs 可增强表皮生长因子（EGF）的分泌。siRNA 敲低 EGF 可减弱 SF-MSCs 对 CIN 诱导的肾功能障碍和肾小管凋亡的抑制作用。
这些发现强烈表明，SF-MSCs 通过旁分泌方式发挥抗细胞凋亡作用改善了模型小鼠的 CIN。因此，SF-MSCs 代表了一种治疗 CIN 的潜在新方法。
