Polysaccharide from Fuzi protects against Ox‑LDL‑induced calcification of human vascular smooth muscle cells by increasing autophagic activity

Abstract

Polysaccharide from Fuzi (FPS) is a water-soluble polysaccharide isolated from the traditional Chinese herbal medicine Fuzi. It has been demonstrated to protect hepatocytes against ischemia-reperfusion injury through its potent antioxidant effects, and to attenuate starvation-induced cytotoxicity in H9c2 cells by increasing autophagic activity. In the present study, Alizarin Red S staining was used to detect mineral deposition and reverse transcription-quantitative polymerase chain reaction was used to detect the core binding factor α1 and smooth muscle 22α mRNA expression. To analyze autophagic activity, western blotting was used to detect microtubule-associated protein 1A/1B light chain 3 and nucleoporin P62 expression. In addition, green fluorescent protein-LC3 dots-per-cell was observed by fluorescence microscopy. It was demonstrated that oxidized low-density lipoprotein (Ox-LDL) could increase the calcification of human vascular smooth muscle cells (VSMCs) in a concentration-dependent manner, and that FPS treatment had a significant protective effect against Ox-LDL-induced calcification of human VSMCs. Furthermore, FPS treatment alleviated the Ox-LDL-induced downregulation of autophagic activity, and the protective effect of FPS on Ox-LDL-induced calcification was attenuated by the autophagy inhibitor 3-methyladenine. In conclusion, the present study demonstrated for the first time to the best of the authors' knowledge that FPS can protect against Ox-LDL-induced vascular calcification in human VSMCs, and that this likely occurs via the activation of autophagy. This supports the hypothesis that autophagy may be an endogenous protective mechanism counteracting vascular calcification, and that FPS may be used as a potential therapeutic for vascular calcification.

Spironolactone dose‑dependently alleviates the calcification of aortic rings cultured in hyperphosphatemic medium with or without hyperglycemia by suppressing phenotypic transition of VSMCs through downregulation of Pit‑1

“…The expression of VSMC differentiation marker genes, including smooth muscle 22α (SM22α) and smooth muscle α-actin (SMα-actin), is decreased during the smooth muscle cell phenotypic transition (10). Meanwhile, Runt-related transcription factor 2 (Runx2; also known as core binding factor α-1, cbfα-1), an important osteoblast-specific gene that regulates osteoblast and chondrocyte differentiation, is expressed in VC (11–13).…”

The Protective Effects of the Autophagic and Lysosomal Machinery in Vascular and Valvular Calcification: A Systematic Review

“…In contrast, intermittent administration of valproic acid did not ameliorate VCN [ 63 ]. Furthermore, FPS attenuated ox-LDL-induced VSMC calcification in vitro [ 64 ]. The authors stated that the protective effects of FPS on VCN are due to its ability to increase autophagy, characterized by an increased LC3-II/LC3-I ratio and decreased p62 expression.…”

“…Other studies confirmed that 3-MA aggravates VSMC calcification [ 52 , 53 , 72 ]. Furthermore, multiple studies added 3-MA, in combination with an autophagy, inducing pharmacological intervention, thereby showing that 3-MA abolishes the beneficial effects of autophagy induction on VCN [ 59 , 61 , 64 , 66 , 67 ]. Additionally, CD137 activation led to JNK-mediated disrupted autophagic flux and aggravated VCN [ 74 ].…”

Natural and non-natural antioxidative compounds: potential candidates for treatment of vascular calcification

“…We identified five types of potential antioxidants with therapeutic effects against VC based on the literature search, including linalool 61 , lipoic acid 22–24 , rosmarinic acid 63 , fermentation broth extracts from Actinobacteria 59 , and polysaccharide from Fuzi product 60 . Two (40%) of them have ROS scavenging ability, while the other three (60%) do not (Fig.…”

“…Finally, extracts of bacterial and plant products are also found to counteract VC experimentally. Preliminary results from Liao et al showed that polysaccharide extracted from Radix Aconiti Carmichaeli , a raw product with anti-oxidant activity, could reduce calcification severity of ox-LDL-treated VSMCs, partially by activating autophagy 60 . Salimi et al also found that metabolites extracted from cultured Nocardia strain could attenuate protein oxidation, reduce inflammation, and reduce VSMC calcification severity 59 .…”