Semaphorin 7A promotes human vascular smooth muscle cell proliferation and migration through theβ-catenin signaling pathway

Background:Vascular smooth muscle cells(VSMCs)undergo a conversion from a contractile phenotype to a proliferative synthetic phenotype,contributing to the pathogenesis of cardiovascular diseases.Semaphorin 7A(SEMA7A)is a glycosylphosphatidylinositol-anchored membrane protein that plays an important role in vascular homeostasis by regulating endothelial cell behaviors.However,the expression and role of SEMA7A in VSMCs remain unclear.Methods:In this study,we screened for VSMC-regulating genes in publicly available datasets and analyzed the expression of SEMA7A in human coronary artery smooth muscle cells(hCASMCs)treated with platelet-derived growth factor-BB(PDGF-BB).The effects of SEMA7A overexpression and knockdown on hCASMC proliferation and migration were examined.The signaling pathways involved in the action of SEMA7A in hCASMCs were determined.Results:Bioinformatic analysis showed that SEMA7A was significantly dysregulated in VSMCs treated with oxidized low-density lipoprotein or overexpressing progerin,a pro-atherogenic gene.The PDGF-BB stimulation led to a concentration-and time-dependent induction of SEMA7A.Depletion of SEMA7A attenuated PDGF-BB-induced hCASMC proliferation and migration.Conversely,overexpression of SEMA7A enhanced hCASMC proliferation and migration.Mechanistically,SEMA7A stimulated the activation of theβ-catenin pathway and upregulated c-Myc,CCND1,and MMP7.Knockdown ofβ-catenin impaired SEMA7A-induced hCASMC proliferation and migration.Conclusions:SEMA7A triggers phenotype switching in VSMCs through theβ-catenin signaling pathway and may serve as a potential therapeutic target for cardiovascular diseases.

The miR-21-5p enriched in the apoptotic bodies of M2 macrophage-derived extracellular vesicles alleviates osteoarthritis by changing macrophage phenotype

Macrophages (Mφs) play a crucial role in the pathological progression of osteoarthritis (OA) by regulating inflammation and tissue repair. Decreasing pro-inflammatory M1-Mφs and increasing anti-inflammatory M2-Mφs can alleviate OA-related inflammation and promote cartilage repair. Apoptosis is a natural process associated with tissue repair. A large number of apoptotic bodies (ABs), a type of extracellular vesicle, are produced during apoptosis, and this is associated with a reduction in inflammation. However, the functions of apoptotic bodies remain largely unknown. In this study, we investigated the role of M2-Mφs-derived apoptotic bodies (M2-ABs) in regulating the M1/M2 balance of macrophages in a mouse model of OA. Our data show that M2-ABs can be targeted for uptake by M1-Mφs, and this reprograms M1-to-M2 phenotypes within 24 h. The M2-ABs significantly ameliorated the severity of OA, alleviated the M1-mediated pro-inflammatory environment, and inhibited chondrocyte apoptosis in mice. RNA-seq revealed that M2-ABs were enriched with miR-21–5p, a microRNA that is negatively correlated with articular cartilage degeneration. Inhibiting the function of miR-21–5p in M1-Mφs significantly reduced M2-ABs-guided M1-to-M2 reprogramming following in vitro cell transfection. Together, these results suggest that M2-derived apoptotic bodies can prevent articular cartilage damage and improve gait abnormalities in OA mice by reversing the inflammatory response caused by M1 macrophages. The mechanism underlying these findings may be related to miR-21-5p-regulated inhibition of inflammatory factors. The application of M2-ABs may represent a novel cell therapy, and could provide a valuable strategy for the treatment of OA and/or chronic inflammation.

A STIR nucleic acid drug delivery system for stirring phenotypic switch of microglia in Parkinson’s disease treatments

Neuroinflammation is one of the three important pathological features in neurodegenerative diseases including Parkinson’s disease(PD).The regulation of neuroinflammation can reduce the severity of neurological damage to alleviate diseases.Numerous studies have shown that the phenotype switch of microglia is tightly associated with the nuclear factorκB(NF-κB)-mediated inflammatory pathway.Therefore,the small interfering RNA(siRNA)therapy for downregulating the expression of NF-κB,provides a promising therapeutic strategy for Parkinson’s disease treatments.Considering the brain delivery challenges of siRNA,a sequential targeting inflammation regulation(STIR)delivery system based on poly(amino acid)s is developed to improve the therapeutic effects of Parkinson’s disease treatments.The STIR system sequentially targets the blood–brain barrier and the microglia to enhance the effective concentration of siRNA in the targeted microglia.The results demonstrate that the STIR nanoparticles can transform microglial phenotypes and regulate brain inflammation,thus achieving neuronal recovery and abnormal aggregation ofα-synuclein protein(α-syn)reduction in the treatment of Parkinson’s disease.Herein,this STIR delivery system provides a promising therapeutic platform in PD treatments and has great potential for other neurodegenerative diseases’therapies.

Bioinspired therapeutic platform based on extracellular vesicles for prevention of arterial wall remodeling in hypertension

Arterial stiffness due to the vessel remodeling is closely linked to raised blood pressure,and its physiopathologic mechanism is still not fully understood.We here aimed to explore whether extracellular vesicle(EV)mediated intercellular communication between endothelium and smooth muscle cell contribute to the blood vessel remodeling under hypertension.We here revealed that the arterial endothelial cells robustly secreted EV,which in turn could be circulated and/or directly taken up by the subendothelial smooth muscle cells(SMC).Under hypertension,the EV secretion increased and the miRNA profile changed significantly mainly due to the raised mechanical force and subsequent enhanced reactive oxygen species generation.Among the miRNA cargos in the EV,miR-320d/423-5p were found increased most significantly.In vivo delivery of miR-320d/423-5p mimics via engineered EV increased their expression in arterial vessels,recapitulating the phenotype in hypertension.In contrast,therapeutic delivery of miR-320d/423-5p inhibitors via engineered EV alleviated the phenotype in spontaneous hypertension rat model.Together,we have found that the injured endothelium due to the raised mechanical force in hypertension contributes to the arterial wall remodeling via the secreted EV.Our study has not only provided novel insights on the mechanism of hypertension associated blood vessel wall remodeling,but also shed light on therapeutic intervention of hypertension associated vascular diseases.