Pharmaceutics & Pharmacokinetics, CSIR-Central Drug Research Institute, Sitapur Road, Lucknow 226031, India.
Pharmaceutics & Pharmacokinetics, CSIR-Central Drug Research Institute, Sitapur Road, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India.
Int J Biol Macromol. 2021 Jul 1;182:760-771. doi: 10.1016/j.ijbiomac.2021.04.064. Epub 2021 Apr 16.
Recent findings suggest that the accumulation of misfolded aggregates of islet amyloid peptide (IAPP) plays an essential role in pancreatic damage and type 2 diabetes (T2D). Pancreastatin (PST), a chromogranin derived peptide, instigates insulin resistance (IR) and promotes T2D. Here, we aimed to investigate whether PST induces IAPP aggregation in the pancreas, liver, and skeletal muscles. Foremost, we unraveled kinetics of fibril formation by ThT kinetic assay, ANS binding, turbidity, and far UV-CD. Subsequently, we checked the microarchitecture of fibril by TEM. Moreover, the PST action on IAPP expression was examined by immunocytochemistry, immunohistochemistry, western blotting, and real-time PCR. The outcome of spectral analysis and TEM demonstrated the fibril formation in the alone IAPP group but not in the alone PST; however, PST with IAPP produced stronger fibril. Moreover, PST was found to stimulate IAPP aggregation and expression more prominently in PANC1 and HepG2 cells, and pancreas and liver tissues than in L6 and skeletal muscle. Subsequently, pancreastatin inhibitor manifested a decline in the extent of the IAPP fibril formation and its expression. To conclude, PST upon combination induces the aggregation of IAPP in the pancreas, liver, and skeletal muscle, which may have the potential to generate IR and cause T2D.
最近的研究结果表明,胰岛淀粉样肽(IAPP)错误折叠聚集体的积累在胰腺损伤和 2 型糖尿病(T2D)中起着至关重要的作用。胰抑素(PST),一种源自嗜铬粒蛋白的肽,会引发胰岛素抵抗(IR)并促进 T2D 的发生。在这里,我们旨在研究 PST 是否会在胰腺、肝脏和骨骼肌中诱导 IAPP 聚集。首先,我们通过 ThT 动力学测定、ANS 结合、浊度和远紫外-CD 揭示了纤维形成的动力学。随后,我们通过 TEM 检查了纤维的微结构。此外,通过免疫细胞化学、免疫组织化学、western blot 和实时 PCR 检查了 PST 对 IAPP 表达的作用。光谱分析和 TEM 的结果表明,在单独的 IAPP 组中形成了纤维,但在单独的 PST 中没有;然而,PST 与 IAPP 产生了更强的纤维。此外,与 L6 和骨骼肌相比,PST 在 PANC1 和 HepG2 细胞以及胰腺和肝脏组织中更能显著刺激 IAPP 聚集和表达。随后,PST 抑制剂表现出 IAPP 纤维形成及其表达程度的下降。总之,PST 结合后会诱导胰腺、肝脏和骨骼肌中 IAPP 的聚集,这可能有潜力产生 IR 并导致 T2D。