Dapagliflozin Improves Angiogenesis after Hindlimb Ischemia through the PI3K-Akt-eNOS Pathway.

Recently, the vascular protective effect of anti-diabetic agents has been receiving much attention. Sodium glucose cotransporter 2 (SGLT2) inhibitors had demonstrated reductions in cardiovascular (CV) events. However, the therapeutic effect of dapagliflozin on angiogenesis in peripheral arterial disease was unclear. This study aimed to explore the effect and mechanism of dapagliflozin on angiogenesis after hindlimb ischemia. We first evaluated the effect of dapagliflozin on post-ischemic angiogenesis in the hindlimbs of rats. Laser doppler imaging was used to detect the hindlimb blood perfusion. In addition, we used immunohistochemistry to detect the density of new capillaries after ischemia. The relevant signaling pathways of dapagliflozin affecting post-ischemic angiogenesis were screened through phosphoproteomic detection, and then the mechanism of dapagliflozin affecting post-ischemic angiogenesis was verified at the level of human umbilical vein endothelial cells (HUVECs). After subjection to excision of the left femoral artery, all rats were randomly distributed into two groups: the dapagliflozin group (left femoral artery resection, receiving intragastric feeding with dapagliflozin (1 mg/kg/d), for 21 consecutive days) and the model group, that is, the positive control group (left femoral artery resection, receiving intragastric feeding with citric acid-sodium citrate buffer solution (1 mg/kg/d), for 21 consecutive days). In addition, the control group, that is the negative control group (without left femoral artery resection, receiving intragastric feeding with citric acid-sodium citrate buffer solution (1 mg/kg/d), for 21 consecutive days) was added. At day 21 post-surgery, the dapagliflozin-treatment group had the greatest blood perfusion, accompanied by elevated capillary density. The results showed that dapagliflozin could promote angiogenesis after hindlimb ischemia. Then, the ischemic hindlimb adductor-muscle tissue samples from three rats of model group and dapagliflozin group were taken for phosphoproteomic testing. The results showed that the PI3K-Akt-eNOS signaling pathway was closely related to the effect of dapagliflozin on post-ischemic angiogenesis. Our study intended to verify this mechanism from the perspective of endothelial cells. In vitro, dapagliflozin enhanced the tube formation, migration, and proliferation of HUVECs under ischemic and hypoxic conditions. Additionally, the dapagliflozin administration upregulated the expression of angiogenic factors phosphorylated Akt (p-Akt) and phosphorylated endothelial nitric oxide synthase (p-eNOS), as well as vascular endothelial growth factor A (VEGFA), both in vivo and in vitro. These benefits could be blocked by either phosphoinositide 3-kinase (PI3K) or eNOS inhibitor. dapagliflozin could promote angiogenesis after ischemia. This effect might be achieved by promoting the activation of the PI3K-Akt-eNOS signaling pathway. This study provided a new perspective, new ideas, and a theoretical basis for the treatment of peripheral arterial disease.

Erratum: Comparative study of nanostructured carriers of calcium phosphate and magnesium phosphate loaded with SRT1720 for the protection of H2O2-induced senescent endothelium.

[This corrects the article on p. 2068 in vol. 10, PMID: 30093944.].

Atorvastatin plus therapeutic ultrasound improve postnatal neovascularization in response to hindlimb ischemia via the PI3K-Akt pathway.

Statins and therapeutic ultrasound (TUS) have been shown to ameliorate angiogenesis on ischemic hindlimb animals and promote human umbilical vein endothelial cells (HUVECs) tube formation and proliferation. Here, we evaluate the therapeutic effect of TUS in combination with atorvastatin (Ator) therapy on angiogenesis in hindlimb ischemia and HUVECs. After subjecting excision of the left femoral artery, all mice were randomly distributed to one of four groups: Control; Ator treated mice (Ator); TUS treated mice (TUS); and Ator plus TUS treated mice (Ator+TUS). At day 14 post-surgery, the Ator plus TUS treatment cohort had the greatest blood perfusion, accompanied by elevated capillary density. In vitro, Ator plus TUS augmented tube formation, migration and proliferative capacities of HUVECs. Additionally, the united administration upregulated expression of angiogenic factors phosphorylated Akt (p-Akt), phosphorylated endothelial nitric oxide synthase (p-eNOS), as well as vascular endothelial growth factor (VEGF), both in vivo and in vitro. These benefits could be blocked by either phosphoinositide 3-kinase (PI3K) or eNOS inhibitor. Our data indicated that the united administration could significantly enhance ischemia-mediated angiogenesis and exert a protective effect against ischemic/hypoxia induced damage among HUVECs through up-regulating VEGF expression and activating the PI3K-Akt-eNOS pathway.

Comparative study of nanostructured carriers of calcium phosphate and magnesium phosphate loaded with SRT1720 for the protection of H2O2-induced senescent endothelium.

Nanostructured calcium phosphate (CaP) and magnesium phosphate (MgP) are promising for the application as the nanocarriers in drug delivery. However, the difference between CaP and MgP nanocarriers in drug delivery is rarely investigated. In this work, we comparatively investigated nanostructured CaP, MgP and calcium magnesium phosphate (CMP) for the delivery of SRT1720, which is a silent information regulator (SIRT1) specific activator with pro-angiogenic and anti-aging properties in response to hydrogen peroxide (H2O2)-induced endothelial senescence. The protection of SRT1720-loaded CaP nanospheres, MgP nanosheets and CMP microspheres on the H2O2-induced senescent endothelium was examined by using human umbilical vein endothelial cells (HUVECs), demonstrating the improved cell viability, anti-aging, tube formation and migration. In addition, the SRT1720-loaded CaP nanospheres, MgP nanosheets and CMP microspheres can rescue the impaired angiogenic potential of HUVECs via activation of Akt/eNOS/VEGF pathway. The SRT1720-loaded MgP nanosheets and CMP microspheres have a similar protective effect compared with the pure SRT1720, while the SRT1720-loaded CaP nanospheres decrease the protective capability of SRT1720. These results lead us to figure out both MgP nanosheets and CMP microspheres are suitable and effective delivery for SRT1720 and this system can be further applied in vivo treatment.

Erratum: Comparative study of nanostructured carriers of calcium phosphate and magnesium phosphate loaded with SRT1720 for the protection of H2O2-induced senescent endothelium.

[This corrects the article on p. 2068 in vol. 10, PMID: 30093944.].