Aim: To assess the potential of human induced pluripotent stem cell-derived smooth muscle cells (hiPSC-SMC) to accelerate diabetic wound healing. Methods: hiPSC-SMC were embedded in 3D collagen scaffolds and cultured in vitro for 72 h; scaffolds were then applied to diabetic, nude mouse, splinted back wounds to assess in vivo healing. Cultured medium after scaffold incubation was collected and analyzed for expression of pro-angiogenic cytokines. Results: hiPSC-SMC secrete increased concentration of pro-angiogenic cytokines, compared with murine adipose derived stem cells. Delivery of hiPSC-SMC-containing collagen scaffolds accelerates diabetic wound healing and is associated with an increased number of total and M2 type macrophages. Conclusion: hiPSC-SMC promote angiogenesis and accelerate diabetic wound healing, making them a promising new candidate for treatment of diabetic wounds.

Objective: Arteriovenous fistulae (AVF) are the preferred vascular access for hemodialysis, but the primary success rate of AVF remains poor. Successful AVF maturation requires vascular wall thickening and outward remodeling. A key factor determining successful AVF maturation is inflammation that is characterized by accumulation of both T-cells and macrophages. We have previously shown that anti-inflammatory (M2) macrophages are critically important for vascular wall thickening during venous remodeling; therefore, regulation of macrophage accumulation may be an important mechanism promoting AVF maturation. Since CD4+ T-cells such as T-helper type 1 cells, T-helper type 2 cells, and regulatory T-cells can induce macrophage migration, proliferation, and polarization, we hypothesized that CD4+ T-cells regulate macrophage accumulation to promote AVF maturation. Approach and Results: In a mouse aortocaval fistula model, T-cells temporally precede macrophages in the remodeling AVF wall. CsA (cyclosporine A; 5 mg/kg, sq, daily) or vehicle (5% dimethyl sulfoxide) was administered to inhibit T-cell function during venous remodeling. CsA reduced the numbers of T-helper type 1 cells, T-helper type 2, and regulatory T-cells cells, as well as M1- and M2-macrophage accumulation in the wall of the remodeling fistula; these effects were associated with reduced vascular wall thickening and increased outward remodeling in wild-type mice. However, these effects were eliminated in nude mice, showing that the effects of CsA on macrophage accumulation and adaptive venous remodeling are T-cell-dependent. Conclusions: T-cells regulate macrophage accumulation in the maturing venous wall to control adaptive remodeling. Regulation of T-cells during AVF maturation may be a strategy that can improve AVF maturation.

No abstract

Objective The glucocorticoid receptor (GR) is a member of the nuclear receptor family that controls key biological processes in the cardiovascular system and has recently been shown to modulate Wnt signaling in endothelial cells. Wnt/β-catenin signaling has been demonstrated to be crucial in the process of angiogenesis. In the current study, we studied whether GR could regulate angiogenesis via the Wnt/β-catenin pathway. Approach and Resultsa Key components of the Wnt/β-catenin pathway were evaluated using quantitative PCR and Western blot in the presence or absence of GR. Enhanced angiogenesis was found in GR deficiency in vitro and confirmed with cell viability assays, proliferation assays and tube formation assays. Consistent with these in vitro findings, endothelial cell-specific GR loss GR in vivo promoted angiogenesis in both a hind limb ischemia model and sponge implantation assay. Results were further verified in a novel mouse model lacking endothelial LRP5/6, a key receptor in canonical Wnt signaling, and showed substantially suppressed angiogenesis using these same in vitro and in vivo assays. To further investigate the mechanism of GR regulation of Wnt signaling, autophagy flux was investigated in endothelial cells by visualizing auto phagolysosomes as well as by assessing P62 degradation and LC3B conversion. Results indicated that potentiated autophagy flux participated in GR-Wnt regulation. Conclusions Lack of endothelial GR triggers autophagy flux, leads to activation of Wnt/β-catenin signaling and promotes angiogenesis. There may also be a synergistic interaction between autophagy and Wnt/β-catenin signaling.

Induced pluripotent stem cells (iPSC) represent an innovative, somatic cell-derived, easily obtained and renewable stem cell source without considerable ethical issues. iPSC and their derived cells may have enhanced therapeutic and translational potential compared with other stem cells. We previously showed that human iPSC-derived smooth muscle cells (hiPSC-SMC) promote angiogenesis and wound healing. Accordingly, we hypothesized that hiPSC-SMC may be a novel treatment for human patients with chronic limb-threatening ischemia who have no standard options for therapy. We determined the angiogenic potential of hiPSC-SMC in a murine hindlimb ischemia model. hiPSC-SMC were injected intramuscularly into nude mice after creation of hindlimb ischemia. Functional outcomes and perfusion were measured using standardized scores, laser Doppler imaging, microCT, histology and immunofluorescence. Functional outcomes and blood flow were improved in hiPSC-SMC-treated mice compared with controls (Tarlov score, p < 0.05; Faber score, p < 0.05; flow, p = 0.054). hiPSC-SMC-treated mice showed fewer gastrocnemius fibers (p < 0.0001), increased fiber area (p < 0.0001), and enhanced capillary density (p < 0.01); microCT showed more arterioles (<96 μm). hiPSC-SMC treatment was associated with fewer numbers of macrophages, decreased numbers of M1-type (p < 0.05) and increased numbers of M2-type macrophages (p < 0.0001). Vascular endothelial growth factor (VEGF) expression in ischemic limbs was significantly elevated with hiPSC-SMC treatment (p < 0.05), and inhibition of VEGFR-2 with SU5416 was associated with fewer capillaries in hiPSC-SMC-treated limbs (p < 0.0001). hiPSC-SMC promote VEGF-mediated angiogenesis, leading to improved hindlimb ischemia. Stem cell therapy using iPSC-derived cells may represent a novel and potentially translatable therapy for limb-threatening ischemia.

No abstract

The purpose of this article was to compare the efficiency and safety of drug-coated balloon angioplasty (DCB) and atherectomy with percutaneous transluminal angioplasty (PTA) in patients with femoropopliteal in-stent restenosis (ISR). Pubmed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) (all up to March 2019) were searched systematically. Trial sequential analysis (TSA) was conducted. 5 studies with 599 participants were included. Compared with PTA, DCB significantly increased the rate of patency (6 months: RR 1.65, 95% CI 1.30 to 2.09, P<0.01; 12 months: RR 2.38, 95% CI 1.71 to 3.30, P<0.01) and the rate freedom from target lesion revascularization (TLR) (6 months: RR 1.18, 95% CI 1.09 to 1.28, P<0.01; 12 months: RR 1.56, 95% CI 1.33 to 1.82, P<0.01) at 6 and 12 months follow-up, and the TSA results showed these outcomes were reliable. The rate of clinical improvement by ≥1 Rutherford category in the DCB group was higher than that in the PTA group (6 months: RR 1.35, 95% CI 1.03 to 1.75, P=0.03; 12 months: RR 1.46, 95% CI 1.17 to 1.82, P<0.01) at 6 and 12 months. There is no statistically difference of ABI, all-cause mortality, and incidence of amputation between DCB group and PTA group (MD 0.03, 95% CI -0.03 to 0.08, P=0.40; RR 1.24, 95% CI 0.46 to 3.34, P=0.67; RR 0.32, 95% CI 0.01 to 7.61, P=0.48). Compared with PTA, the rate of patency and freedom from TLR in the laser atherectomy (LD) group was higher than that in the PTA group (patency: 6 months: RR 1.28, 95% CI 1.01 to 1.64, P<0.05, 12 months: RR 2.25, 95% CI 1.14 to 4.44, P<0.05; freedom from TLR: 6 months: RR 1.27, 95% CI 1.05 to 1.53, P=0.01, 12 months: RR 1.59, 95% CI 1.12 to 2.25, P=0.01) at 6 and 12 months follow-up. In conclusion, DCB and LD had superior clinical (freedom from TLR and clinical improvement) and angiographic outcomes (patency rate) compared with PTA for the treatment of femoropopliteal ISR. Moreover, DCB and LD had a low incidence of amputation and mortality and were relatively safe methods.

To examine the complications of brachial and axillary artery punctures and the precautionary measures taken to lower their incidences. Retrospective analysis of 266 cases of brachial and axillary artery punctures was performed for angiography or angioplasty between January 2009 and December 2013 at the Department of Vascular Surgery, Xuanwu Hospital, Capital Medical University. Complications and their causes were assessed. Among all brachial artery punctures (n = 140), there were complications in 3.6 per cent of cases, including local hematoma in 1.4 per cent, pseudoaneurysm in 0.7 per cent, acute arterial thrombosis in 0.7 per cent, and median nerve injury in 0.7 per cent. Among all axillary artery punctures (n = 126), there were complications in 10.3 per cent of cases, including local hematoma in 4.8 per cent, pseudoaneurysm in 0.8 per cent, acute arterial thrombosis in 0.8 per cent, acute venous thrombosis in 0.8 per cent, and nerve injury in 3.2 per cent. The incidence of complications was significantly lower in brachial axillary artery puncture compared with axillary artery puncture ( P < 0.05). The main factors associated with complications might be patient's vascular condition, perioperative medication, anatomical features of the artery, puncture site, successful rate of first-attempt puncture, and bandage strength. Incidence of complications of brachial and axillary artery punctures could be lowered by strengthening the choice of indications, improving the perioperative managements, being fully aware of the anatomical characteristics of the brachial and axillary arteries, and applying the standardized techniques of puncture and compression hemostasis.