Cystatin C as a potential therapeutic mediator against Parkinson’s disease via VEGF-induced angiogenesis and enhanced neuronal autophagy in neurovascular units

Abstract

Cystatin C (CYS C, Cst3) is an endogenous cysteine protease inhibitor that plays neuroprotective roles in neurodegenerative diseases. We aimed to explore the association of CYS C with Parkinson’s disease (PD) models and investigate its involvement in the role of neurovascular units (NVUs) in PD neuro-pathogenesis. We used A53T α-synuclein (SNCA) transgenic mice and 6-hydroxydopamine-lesioned DAergic PC12 cells as experimental PD models to investigate the mechanisms behind this association. The injections of CYS C were administered to the right substantia nigra (SN) of A53T SNCA transgenic mice to measure the effects of CYS C in transgenic A53T SNCA mice. To explore the angiogenesis in vivo and in vitro, we used the chick embryo chorioallantoic membrane (CAM) assay and tube formation (TF) assay. We found that CYS C has a neuroprotective effect in this in vivo PD model. We observed increased VEGF, NURR1 and autophagy markers LC3B and decreased SNCA and apoptosis marker cleaved CASP3 in different brain regions of CYS C-treated A53T SNCA transgenic mice. In vitro, we observed that CYS C-induced VEGF, a secreted protein, attenuated 6-OHDA-lesioned DAergic PC12 cell degeneration by regulating p-PKC-α/p-ERK1/2-Nurr1 signaling and inducing autophagy. VEGF-mediated angiogenesis was markedly enhanced in the conditioned media of 6-OHDA-lesioned PC12 cells with CYS C-overexpression, whereas blockage of autophagy in CYS C-overexpressing PC12 cells significantly downregulated VEGF expression and the associated angiogenesis. Our data indicate that CYS C displays dual neuronal–vascular functions, promoting PC12 cell survival and angiogenesis via regulating the level of secreted VEGF in NVUs. Our study provides evidence that may aid in the development of an alternative approach for the treatment of PD through modulation of CYS C-mediated neuronal-vascular pathways.

Single-cell transcriptomics of the aged mouse brain reveals convergent, divergent and unique aging signatures

“…Network analysis showed that both cystatin C ( Cst3 ; an aging-downregulated gene), and stromal cell-derived factor 1 ( Cxcl12 ; an aging-upregulated gene) (see Fig. 3B), which have been previously linked to multiple pathologies 40–43 , are common mediators of crosstalk between vascular cells and many brain cell types (Fig. 6B-C and Table S9).…”

Protein Kinase C Isozymes and Autophagy during Neurodegenerative Disease Progression

“…Each isozyme has a diverse role in the pathway due to its phosphorylation abilities. Various functions of PKCs in main autophagy pathways such as PI3K/Akt /mTOR/Erk have been reported in several studies [83][84][85][86] (Figure 4).…”

Autophagy attenuates postoperative cognitive dysfunction by up-regulating cystatin C in aged rats undergoing splenectomy

“…In our study, levels of Cys C protein and mRNA correlated positively with autophagy levels, suggesting that autophagy may activate Cys C expression in hippocampus. Up-regulation of Cys C exerts neuroprotective effects in Alzheimer's disease, amyotrophic lateral sclerosis and subarachnoid hemorrhage by inducing autophagy and angiogenesis in the brain [8,29,30].…”