miR548ai antagonism attenuates exosome-induced endothelial cell dysfunction.

Endothelial cell (EC) and smooth muscle cell (SMC) are major cell types adjacent in the vascular wall. Recent progress indicates that their communication is crucial for vascular homeostasis and pathogenesis. In particular, dysfunctional (proliferative) SMCs through exosomes can induce EC dysfunction (impaired growth). The current study suggests that miR548ai, a rarely known microRNA, may provide a molecular target for protection against SMC/exosome-induced EC dysfunction. We performed microarray profiling of microRNAs of dysfunctional human primary aortic SMCs induced by different cytokines (PDGF-BB, TGFß1, TNFα, IL1ß). Among the microRNAs commonly upregulated by these cytokines, miR548ai showed the most robust changes, as also validated through quantitative PCR. This cytokine-induced miR548ai upregulation was recapitulated in the qPCR determination of SMC-derived exosomal microRNAs. Consistent with SMC-to-EC communication, the exosomes extracted from cytokine-stimulated SMCs impaired human EC proliferation and migration. Of particular interest, this SMC exosomal impingement on ECs was countered by transfection of miR548ai inhibitor microRNA into ECs. Furthermore, the miR548ai inhibitor transfected into SMCs attenuated SMC dysfunction/proliferation. Thus, these results identify miR548ai as a novel target; namely, miR548ai inhibitor mitigates EC dysfunction induced by exosomes derived from dysfunctional SMCs. This new knowledge may aid the future development of microRNA-based treatment of vascular disorders.

ALDH1A3 Regulations of Matricellular Proteins Promote Vascular Smooth Muscle Cell Proliferation.

Vascular smooth muscle cell (VSMC) proliferation promotes intimal hyperplasia (IH) in occluding vascular diseases. Here we identified a positive role of ALDH1A3 (an aldehyde dehydrogenase) in this pro-IH process. The expression of ALDH1A3, but not that of 18 other isoforms of the ALDH family, was substantially increased in cytokine-stimulated VSMCs. PDGF(BB) stimulated VSMC total ALDH activity and proliferation, whereas ALDH1A3 silencing abolished this effect. ALDH1A3 silencing also diminished the expression of two matricellular proteins (TNC1 and ESM1), revealing a previously unrecognized ALDH1A3 function. Loss-of-function experiments demonstrated that TNC1 and ESM1 mediated ALDH1A3's pro-proliferative function via activation of AKT/mTOR and/or MEK/ERK pathways. Furthermore, ALDH inhibition with disulfiram blocked VSMC proliferation/migration in vitro and decreased TNC1 and ESM1 and IH in angioplasty-injured rat carotid arteries. Thus, ALDH1A3 promotes VSMC proliferation at least partially through TNC1/ESM1 upregulation; dampening excessive ALDH1A3 activity represents a potential approach to IH mitigation.

National outcomes for the treatment of ruptured abdominal aortic aneurysm: comparison of open versus endovascular repairs.

OBJECTIVES: Endovascular repair (EVAR) of ruptured abdominal aortic aneurysms (rAAA) has been shown to acutely decrease procedural mortality compared to open aortic repair (OAR). However, little is known about the effect of choice of procedure; EVAR vs OAR, or the impact of physician and institution volume on long-term survival and outcome. METHODS: Patients hospitalized with rAAA who underwent either OAR or EVAR, were derived from the Medicare inpatient dataset (1995-2004) using ICD9 codes. We evaluated long-term survival after OAR and EVAR in the entire fee-for-service Medicare population, and then in patients matched by propensity score to create two similar cohorts for comparison with Kaplan-Meier analysis. Annual surgeon and hospital volumes of EVAR (elective and ruptured), OAR (elective and ruptured), and rAAA (EVAR and OAR) were divided into quintiles to determine if increasing volumes correlate with decreasing mortality. Predictors of survival were determined by Cox modeling. RESULTS: A total of 43,033 Medicare beneficiaries had rAAA repair: 41,969 had OAR and 1,064 had EVAR. The proportions of patients with diabetes, hypertension, cardiovascular, cerebrovascular, renal disease, hyperlipidemia, and cancer were statistically higher in the EVAR than in the OAR group, whereas lower extremity vascular disease was higher in the OAR group. The initial evaluation of EVAR vs OAR, prior to propensity matching, showed no statistical advantage in EVAR-survival after 90 days. The survival analysis of patients matched by propensity score showed a benefit of EVAR over OAR that persisted throughout the 4 years of follow-up (P = .0042). Perioperative and long-term survival after rAAA repair correlated with increasing annual surgeon and hospital volume in OAR and EVAR and also with rAAA experience. EVAR repair had a protective effect (HR = 0.857, P = .0061) on long-term survival controlling for comorbidities, demographics, and hospital and surgeon volume. CONCLUSION: When EVAR and OAR patients are compared using a reliable statistical technique such as propensity analysis, the perioperative survival advantage of rAAA repaired endovascularly is maintained over the long term. Institutional experience with rAAA is critical for survival after either OAR or EVAR.

Current management of extracranial carotid artery disease.

Stroke is the third most common cause of death in the United States. There are approximately 700,000 strokes/year, eighty percent are ischemic, and 20-30% of ischemic strokes are secondary to carotid disease. Carotid stenosis is traditionally treated by carotid endarterectomy (CEA). Multicenter randomized controlled trials have shown that surgery significantly reduces the risk of ipsilateral stroke in patients with severe symptomatic and asymptomatic carotid stenosis. Endovascular techniques for treating carotid stenosis have been developed over recent years. Carotid angioplasty and stenting (CAS) with cerebral protection has become an alternative to CEA for high-surgical-risk patients and the procedure of choice for stenoses inaccessible by surgery. In this review we summarize the existing data regarding the traditional state of management of extracranial carotid artery stenosis, and compare these data to a critical analysis of the recent results of CAS.

Blood pool MR angiography of aortic stent-graft endoleak.

OBJECTIVE: The purpose of our research was to investigate the value of a blood pool contrast agent in detecting endoleaks on MR angiography after endoluminal stent-graft repair of infrarenal aortic aneurysms. CONCLUSION: Blood pool MR angiography using Ferumoxytol reveals more aortic stent-graft endoleaks than does CT angiography and depicts more endoleaks 24 hr after administration than during the immediate arterial phase because of a 50-fold increase in the volume of enhancement in the aneurysmal sac outside the stent-graft.

Transduction of peptide analogs of the small heat shock-related protein HSP20 inhibits intimal hyperplasia.

BACKGROUND: Human saphenous vein (HSV) is the autologous conduit of choice for peripheral vascular reconstructions. However, vasospasm can lead to early graft failure. The leading cause of delayed graft failure is intimal hyperplasia. OBJECTIVE: To develop a proteomic approach to prevent vein-graft spasm and intimal hyperplasia. METHODS: Biomimetic peptide analogs of the small heat shock-related protein HSP20, containing a protein transduction domain (PTD), a phosphorylated serine, and a sequence of HSP20 surrounding the phosphorylation site (PTD-pHSP20), or a scrambled sequence of the same amino acids surrounding the phosphorylation site (PTD-scHSP20) were synthesized. The peptides were used in muscle bath and organ culture experiments with human saphenous vein (HSV) segments. Cultured smooth muscle cell lines were used to determine the effect of the peptides on proliferation and migration. RESULTS: In HSV rings precontracted with norepinephrine, PTD-pHSP20 but not PTD-scHSP20 led to relaxation. There was no significant difference in smooth muscle cell proliferation in cells treated with PTD-pHSP20 compared with PTD-scHSP20. Treatment with PTD-pHSP20 significantly inhibited cellular migration compared with PTD-scHSP20. Control, untreated, and PTD-scHSP20-treated saphenous veins had significant increases in intimal thickness after culture. This intimal thickening was completely inhibited by treatment with PTD-pHSP20. CONCLUSIONS: Protein transduction of biologically active motifs of HSP20 can affect pathologic and physiologic responses of HSV and represents a novel proteomic-based therapeutic approach. CLINICAL RELEVANCE: We have been a part of the genomics era and are now viewing the emergence of "proteomics." The genome is linear and relatively easy to examine; however the proteome is much more complex and dynamic. In essence, the purpose of gene therapy is to manipulate the genome to produce a particular protein. This manuscript describes a new proteomic approach in which the biologically active part of a protein is directly introduced into vascular cells. Peptides were synthesized which contained a total of 24 amino acids, 11 of which represent a protein transduction domain or "carrier" while the other 13 are the biologically active "cargo." These synthetic peptides prevent spasm (contraction) and intimal hyperplasia in segments of human saphenous vein treated ex vivo. Preclinical development is currently underway to develop these molecules as a proteomic-based vein harvest solution to enhance vein-graft patency.

Naked plasmid DNA encoding fibroblast growth factor type 1 for the treatment of end-stage unreconstructible lower extremity ischemia: preliminary results of a phase I trial.

OBJECTIVE: The objective of this study was to evaluate the safety and tolerance of increasing single and repeated (n = 2) doses of intramuscular naked plasmid DNA encoding for fibroblast growth factor (FGF) type 1 (NV1FGF) administered to patients with unreconstructible end-stage peripheral arterial occlusive disease (PAD). The secondary objectives were to determine the biologic activity of NV1FGF on hemodynamic and clinical parameters associated with improved perfusion. METHODS: Fifty-one patients with unreconstructible peripheral arterial occlusive disease with rest pain or tissue necrosis underwent treatment with intramuscular NV1FGF. Increasing single (500, 1000, 2000, 4000, 8000, and 16,000 microg) and repeated (2 x 500, 2 x 1000, 2 x 2000, 2 x 4000, and 2 x 8000 microg) doses of NV1FGF were injected into the ischemic thigh and calf. Arteriography was performed before treatment and was repeated 12 weeks after treatment. Side effects and serious adverse events were monitored. Measurements of plasma and urine levels were performed to evaluate NV1FGF plasmid distribution. Serum FGF-1 was measured as an analysis of gene expression at the protein level. Transcutaneous oxygen pressure, ankle brachial index, toe brachial index, pain assessment with visual analog scale, and ulcer healing also were assessed. The safety results are presented for 51 patients, and the clinical outcomes are presented for the first 15 patients (500 to 4000 microg) who completed the 6-month follow-up study. RESULTS: NV1FGF was well tolerated. Sixty-six serious adverse events were reported; however, none were considered to be related to NV1FGF. Four patients had adverse events that were possibly or probably related to the study treatment: injection site pain, pain, peripheral edema, myasthenia, and paresthesia. No laboratory adverse events were related to the study treatment. Two deaths remote from the treatment were considered not related. Biodistribution of plasmid was limited and transient in plasma and absent in urine. No increase in the FGF-1 serum level was detected. A significant reduction in pain (P <.001) and aggregate ulcer size (P <.01) was associated with an increased transcutaneous oxygen pressure (P <.01) as compared with baseline pretreatment values. A significant increase in ankle brachial index (P <.01) was seen. CONCLUSION: NV1FGF is well tolerated and potentially could be effective for the treatment of patients with end-stage limb ischemia. Biologic parameters indicate improved perfusion after NV1FGF administration. Dose response is not yet evident. The safety of NV1FGF and the magnitude of improvement observed in this study encourage further investigation with a placebo-controlled, double-blind clinical trial.