该研究旨在鉴定具有减轻肾损伤潜力的小分子。首先在25、50和75mg/kg体重的不同剂量的缺血再灌注的急性肾损伤模型下评估了两种天然化合物环(Val-Pro)(1)和环(Leu-羟基-Pro)(2)。Further,对化合物进行抗霉素A诱导的缺血体外研究(NRK-52E细胞系)。两种化合物均显著降低血浆IL-1β水平(P<0.05)。此外,炎症标志物的mRNA表达水平(TNF-α,IL-6和IL-1β)和肾损伤标志物(KIM-1,NGAL,由于缺血再灌注,肾脏组织中的α-GST和π-GST)随着组织学损伤的改善和对中性粒细胞浸润的控制而显着减轻(P<0.01)。体外研究表明,通过调节Bax对抗霉素A诱导的细胞毒性(P<0.05)和抗凋亡作用,半胱天冬酶3(pro和裂解)和BCL2,膜联蛋白+PI+细胞减少。Further,在小鼠肾损伤的慢性单侧输尿管梗阻模型和TGF-β诱导的体外纤维化模型(NRK-49F细胞系)中评估了化合物cyclo(Val-Pro)(1)(50mg/kg体重剂量)。Cyclo(Val-Pro)(1)显着降低纤维化标志物(胶原蛋白1,α-SMA和TGF-β)的表达水平,并显示肾纤维化的显着缓解(天狼星红染色)。此外,在免疫组织化学研究中,TGF-β诱导的NRK-49F细胞的增殖显着降低,胶原蛋白1和α-SMA的水平降低。总之,该化合物通过抑制肾脏炎症和肾小管上皮细胞凋亡而显著消除缺血性损伤。Further,cyclo(Val-Pro)(1)通过抑制成纤维细胞活化和增殖表现出显著的抗纤维化活性。因此,这些基于脯氨酸的环状二肽被推荐作为治疗肾损伤的药物先导.
The study aimed to identify small molecules having potentiality in alleviating renal injury. Two natural compounds cyclo(Val-Pro) (1) and cyclo(Leu-Hydroxy-Pro) (2) were first evaluated under acute renal injury model of ischemic reperfusion at different doses of 25, 50 and 75 mg/kg body weight. Further, the compounds were subjected to antimycin A-induced ischemic in vitro study (NRK-52E cell lines). Both the compounds significantly decreased plasma IL-1β levels (P < 0.05). Also, the mRNA expression levels of inflammatory markers (TNF-α, IL-6 and IL-1β) and renal injury markers (KIM-1, NGAL, α-GST and π-GST) in the renal tissues were significantly alleviated (P < 0.01) along with the improvement in histological damage and control over neutrophil infiltration as a result of ischemic reperfusion. The in vitro study revealed the protective effect against antimycin A-induced cytotoxicity (P < 0.05) and antiapoptotic effect acting through the regulation of Bax, caspase 3 (pro and cleaved) and BCL2 with reduction in Annexin+PI+ cells. Further, the compound cyclo(Val-Pro) (1) was evaluated (50 mg/kg body weight dose) in chronic unilateral ureter obstruction model of renal injury in mice and TGF-β-induced in vitro fibrotic model (NRK-49F cell lines). Cyclo(Val-Pro) (1) significantly reduced the expression levels of fibrotic markers (collagen-1, α-SMA and TGF-β) and showed marked alleviation of renal fibrosis (sirius red staining). Also, the proliferation of TGF-β-induced NRK-49F cells was significantly reduced along with decreased levels of collagen-1 and α-SMA in immunohistochemistry studies. In conclusion, the compounds significantly abrogated ischemic injury by inhibiting renal inflammation and tubular epithelial apoptosis. Further, cyclo (Val-Pro) (1) exhibited significant anti-fibrotic activity through the inhibition of fibroblast activation and proliferation. Thus, these proline-based cyclic dipeptides are recommended as drug leads for treating renal injury.