Blocking exosomal miRNA-153-3p derived from bone marrow mesenchymal stem cells ameliorates hypoxia-induced myocardial and microvascular damage by targeting the ANGPT1-mediated VEGF/PI3k/Akt/eNOS pathway.

It has been widely reported that exosomes derived from mesenchymal stem cells (MSCs) have a protective effect on myocardial infarction (MI). However, the specific molecules which play a damaging role in MSCs shuttled miRNAs are much less explored. MiRNA-153-3p (miR-153-3p) is a vital miRNA which has been proved to modulate cell proliferation, apoptosis, angiogenesis, peritoneal fibrosis and aortic calcification. Here, we aim to study the effect and mechanism of miR-153-3p in MSC-derived exosomes on hypoxia-induced myocardial and microvascular damage. The exosomes of MSCs were isolated and identified, and the MSCs-exosomes with low expression of miR-153-3p (exo-miR-153-3p-) were constructed to interfere with the endothelial cells and cardiomyocytes in the oxygen-glucose deprivation (OGD) model. The viability, apoptosis, angiogenesis of endothelial cells and cardiomyocytes were determined. Additionally, ANGPT1/VEGF/VEGFR2/PI3K/Akt/eNOS pathway was detected by ELISA and/or western blot. The results illustrated that exo-miR-153-3p- significantly reduced the apoptosis of endothelial cells and cardiomyocytes and promoted their viability. Meanwhile, exo-miR-153-3p- can promote the angiogenesis of endothelial cells. Mechanistically, miR-153-3p regulates the VEGF/VEGFR2/PI3K/Akt/eNOS pathways by targeting ANGPT1. Intervention with VEGFR2 inhibitor (SU1498, 1 µM) remarkably reversed the protective effect of exo-miR-153-3p- in vascular endothelial cells and cardiomyocytes treated by OGD. Collectively, MSCs-derived exosomes with low-expressed miR-153-3p notably promotes the activation of ANGPT1 and the VEGF/VEGFR2 /PI3K/Akt/eNOS pathways, thereby preventing the damages endothelial cells and cardiomyocytes against hypoxia.

Impact of CYP2C19 Polymorphism on Antiplatelet Potency of Prasugrel 5 and 10 mg Daily Maintenance.

BACKGROUND: Whether genetic polymorphisms (GP) impact residual platelet aggregation (RPA) following prasugrel is unclear, especially during maintenance phase. We assessed the influence of CYP2C19 GP carriers on RPA in the prospective observational cohort study. METHODS AND RESULTS: All post-stent patients (n = 206) received prasugrel 60 mg loading and either 5 or 10 mg daily maintenance with aspirin100 mg. RPA levels by light transmission aggregometry (LTA), multiplate electrode aggregometry (MEA), and VerifyNow (P2Y12 reaction units, PRU) with CYP2C19 GP were measured simultaneously. Demographics and clinical characteristics were not useful for predicting response after prasugrel. GP carriers exhibited higher RPA (PRU: p = 0.001, LTA: p = 0.001, MEA: p = 0.023) than noncarriers. CYP2C19 carriers had higher RPA for 5 mg (n = 35; LTA: p = 0.043, MEA: p = 0.023) and reached significance for 10 mg (n = 27; LTA: p = 0.001, PRU: p = 0.001) prasugrel. When divided into extensive, intermediate, and poor metabolizers, all exhibited statistical differences among the 3 groups (LTA: 14.9 ± 12.3%, 22.6 ± 14.9%, 22.9 ± 15.6%, p = 0.002; PRU: 104.1 ± 70.8%, 141.8 ± 78.0%, 151.0 ± 84.8%, p = 0.003; MEA: 19.7 ± 8.9%, 24.4 ± 12.2%, 28.1 ± 14.7%, p = 0.002). CONCLUSION: CYP2C19 GP impacts RPA during maintenance phase prasugrel in Korean outpatients. This effect is consistent for both of the approved prasugrel doses potentially affecting long-term outcomes including bleeding risks. However, the clinical utility of these findings is still uncertain, and requires more evidence from larger randomized trials beyond East Asians.

CYP2C19 but not CYP2B6, CYP3A4, CYP3A5, ABCB1, PON1 or P2Y12 genetic polymorphism impacts antiplatelet response after clopidogrel in Koreans.

Clopidogrel response variability (CRV) is well documented, and may affect clinical outcomes. Impact of genetic polymorphisms is important for assessing and predicting CRV. The extensive evidence indicates the importance of CYP2C19 variants in reducing efficacy of clopidogrel. This study defined the impact of numerous genetic polymorphisms on CRV before and after percutaneous coronary interventions (PCI) exclusively in a Korean cohort assuming less genetic variability noise. One hundred and thirty-six patients of Korean origin undergoing PCI were included. Platelet reactivity was measured by VerifyNow assay before and after PCI. Genetic polymorphism of seven single nucleotides of CYP2B6, CYP2C19, CYP3A4, CYP3A5, ABCB1, PON1, and P2Y12 were evaluated and matched with platelet reactivity. Carriers of at least one CYP2C19*2 or *3 allele uniformly exhibited higher platelet reactivity compared to 0-carrier pre-PCI (odds ratio 3.1, 95% confidence interval 1.4-6.9, P < 0.01) and post-PCI (odds ratio 3.4, 95% confidence interval 1.7-6.8, P < 0.001). The carriers of other gene allele variants lack uniformed impact on CRV. The Korean carriers of CYP2C19*2 or *3 allele are linked to CRV, whereas CYP2B6, CYP3A4, CYP3A5, ABCB1, PON1, and P2Y12 failed to predict CRV. The exact clinical utility of these findings is uncertain, and requires a large randomized national trial for proof of concept.

Characteristics of circulating CD31(+) cells from patients with coronary artery disease.

Recently, we reported the properties of CD31-expressing cells in healthy individuals. However, the characteristics of CD31-expressing cells derived from coronary artery disease (CAD) patients remain unknown. This study aimed to investigate the relationship between circulating CD31(+) cells and CAD as well as their biological characteristics. Analysis with flow cytometry revealed that CD31(+) cells (C-CD31) from the peripheral blood (PB) of CAD patients exhibited low levels of T-cell marker and high levels of macrophage marker compared with the PB-CD31(+) cells from healthy individuals (H-CD31). In addition, the expression levels of multiple pro-angiogenic and chemokine genes were significantly down-regulated in C-CD31. However, inflammatory gene IL-1α was highly up-regulated in C-CD31. Patients with unstable angina (UA) had significantly more CD31(+) cells in the PB than healthy control group (P < 0.001). Moreover, there were significant correlations between the number of CD31(+) cells and cardiovascular (CV) disease activity (R = 0.318, P = 0.006) and the number of diseased coronaries (R = 0.312, P = 0.005). For the diagnostic category of UA, the area under curve was 0.803 (P < 0.001). In conclusion, C-CD31 have impaired angiogenic potential and the number of circulating CD31(+) cells were correlated with CV risk. These findings may contribute to the understanding of the pathogenesis of CAD.

Amniotic mesenchymal stem cells display neurovascular tropism and aid in the recovery of injured peripheral nerves.

Recently, we reported that human amniotic membrane-derived mesenchymal stem cells (AMMs) possess great angiogenic potential. In this study, we determined whether local injection of AMMs ameliorates peripheral neuropathy. AMMs were transplanted into injured sciatic nerves. AMM injection promoted significant recovery of motor nerve conduction velocity and voltage amplitude compared to human adipose-derived mesenchymal stem cells. AMM implantation also augmented blood perfusion and increased intraneural vascularity. Whole-mount fluorescent imaging analysis demonstrated that AMMs exhibited higher engraftment and endothelial incorporation abilities in the sciatic nerve. In addition, the higher expression of pro-angiogenic factors was detected in AMMs injected into the peripheral nerve. Therefore, these data provide novel therapeutic and mechanistic insights into stem cell biology, and AMM transplantation may represent an alternative therapeutic option for treating peripheral neuropathy.

Amniotic mesenchymal stem cells enhance wound healing in diabetic NOD/SCID mice through high angiogenic and engraftment capabilities.

Although human amniotic mesenchymal stem cells (AMMs) have been recognised as a promising stem cell resource, their therapeutic potential for wound healing has not been widely investigated. In this study, we evaluated the therapeutic potential of AMMs using a diabetic mouse wound model. Quantitative real-time PCR and ELISA results revealed that the angiogenic factors, IGF-1, EGF and IL-8 were markedly upregulated in AMMs when compared with adipose-derived mesenchymal stem cells (ADMs) and dermal fibroblasts. In vitro scratch wound assays also showed that AMM-derived conditioned media (CM) significantly accelerated wound closure. Diabetic mice were generated using streptozotocin and wounds were created by skin excision, followed by AMM transplantation. AMM transplantation significantly promoted wound healing and increased re-epithelialization and cellularity. Notably, transplanted AMMs exhibited high engraftment rates and expressed keratinocyte-specific proteins and cytokeratin in the wound area, indicating a direct contribution to cutaneous closure. Taken together, these data suggest that AMMs possess considerable therapeutic potential for chronic wounds through the secretion of angiogenic factors and enhanced engraftment/differentiation capabilities.