Biomarkers and molecular endotypes of sarcoidosis: lessons from omics and non-omics studies.

Sarcoidosis is a chronic granulomatous disorder characterized by unknown etiology, undetermined mechanisms, and non-specific therapies except TNF blockade. To improve our understanding of the pathogenicity and to predict the outcomes of the disease, the identification of new biomarkers and molecular endotypes is sorely needed. In this study, we systematically evaluate the biomarkers identified through Omics and non-Omics approaches in sarcoidosis. Most of the currently documented biomarkers for sarcoidosis are mainly identified through conventional "one-for-all" non-Omics targeted studies. Although the application of machine learning algorithms to identify biomarkers and endotypes from unbiased comprehensive Omics studies is still in its infancy, a series of biomarkers, overwhelmingly for diagnosis to differentiate sarcoidosis from healthy controls have been reported. In view of the fact that current biomarker profiles in sarcoidosis are scarce, fragmented and mostly not validated, there is an urgent need to identify novel sarcoidosis biomarkers and molecular endotypes using more advanced Omics approaches to facilitate disease diagnosis and prognosis, resolve disease heterogeneity, and facilitate personalized medicine.

"Modern Endovascular Therapy".

INTRODUCTION: The past 25 years have been witness to a revolution in how vascular care is delivered. The majority of arterial and venous interventions have converted from open surgery to minimally invasive percutaneous endovascular procedures. METHODS: This surgical innovations symposium article reviews current endovascular therapy in multiple vascular beds with a primary focus on carotid artery occlusive disease, aortic pathologies, and lower extremity arterial occlusive disease. Mesenteric arterial occlusive disease and lower extremity venous endovascular therapies are also briefly discussed. Indications for intervention, treatment examples and outcomes analysis are presented. While not reviewed in this article, endovascular therapy has also become first line in the treatment of coronary artery disease, chronic mesenteric arterial occlusive disease, superficial venous reflux, central vein occlusion, and acute venous thrombus intervention when indicated. CONCLUSION: Endovascular therapies are used in all vascular beds to treat the full spectrum of vascular pathologies. Aneurysm disease, atherosclerotic arterial occlusive disease, acute arterial and venous thrombosis, ongoing hemorrhage, and venous reflux are among the issues which can be addressed by endovascular means. The minimally invasive nature of endovascular treatments in what is largely a very co-morbid patient cohort is an attractive method of avoiding major procedural related morbidity and mortality.

Thrombospondin-5 and fluvastatin promote angiogenesis and are protective against endothelial cell apoptosis.

The thrombospondins (TSPs), multifunctional matricellular proteins, are known mediators of endothelial cell (EC) angiogenesis and apoptosis. TSP-1, an antiangiogenic molecule, is important in the progression of vascular disease, in part by inducing EC apoptosis. TSP-2, although less studied, also induces EC apoptosis and inhibits angiogenesis. The effects of TSP-5 are largely unexplored in ECs, but TSP-5 is believed to be protective against arterial disease. Statin drugs have been shown to have beneficial pleiotropic effects, including decreasing EC apoptosis, increasing angiogenesis, and blocking TSP signaling. We hypothesized TSP-5 will be proangiogenic and antiapoptotic, and statin pretreatment would reverse the proapoptotic and antiangiogenic phenotype of TSP-1 and TSP-2. ECs were exposed to serum-free medium, TSP-1, TSP-2, or TSP-5 with or without fluvastatin pretreatment. Quantitative real-time polymerase chain reaction was performed on 96 apoptosis and 96 angiogenesis-related genes using microfluidic card assays. Angiogenesis was measured using Matrigel assays, while apoptosis was measured by fluorescent caspase assay. TSP-5 suppressed apoptotic genes and had a mixed effect on the angiogenic genes; however, TSP-5 did not alter apoptois but was proangiogenic. Pretreatment with fluvastatin downregulated proapoptotic genes and apoptosis and upregulated proangiogenic genes and angiogenesis. Findings indicate TSP-5 and fluvastatin have a protective effect on ECs, being proangiogenic and reversing the antiangiogenic effects of TSP-1 and TSP-2. In conclusion, TSP-5 and fluvastatin may be beneficial for inducing angiogenesis in the setting of ischemia.

Inhibition of heat shock protein 90 attenuates post­angioplasty intimal hyperplasia.

Intimal hyperplasia (IH) is a pathologic process that leads to restenosis after treatment for peripheral arterial disease. Heat shock protein 90 (HSP90) is a molecular chaperone that regulates protein maturation. Activation of HSP90 results in increased cell migration and proliferation. 17­N­allylamino­17­demethoxygeldanamycin (17­AAG) and 17­dimethylaminoethylamino­17­demethoxygeldanamycin (17­DMAG) are low toxicity Food and Drug Association approved HSP90 inhibitors. The current study hypothesized that HSP90 inhibition was predicted to reduce vascular smooth muscle cell (VSMC) migration and proliferation. In addition, localized HSP90 inhibition may inhibit post­angioplasty IH formation. For proliferation, VSMCs were treated with serum­free media (SFM), 17­DMAG or 17­AAG. The selected proliferative agents were SFM, platelet derived growth factor (PDGF) or fibronectin. After three days, proliferation was measured. For migration, VSMCs were treated with SFM, 17­AAG or 17­DMAG with SFM, PDGF or fibronectin as chemoattractants. Balloon injury to the carotid artery was performed in rats. The groups included in the present study were the control, saline control, 17­DMAG in 20% pluronic gel delivered topically to the adventitia or intraluminal delivery of 17­DMAG. After 14 days, arteries were fixed and sectioned for morphometric analysis. Data was analyzed using ANOVA or a student's t­test. P<0.05 was considered to indicate a statistically significant difference. The results revealed that 17­AAG and 17­DMAG had no effect on cell viability. PDGF and fibronectin also increased VSMC proliferation and migration. Furthermore, both 17­AAG and 17­DMAG decreased cell migration and proliferation in all agonists. Topical adventitial treatment with 17­DMAG after balloon arterial injury reduced IH. HSP90 inhibitors suppressed VSMC proliferation and migration without affecting cell viability. Topical treatment with a HSP90 inhibitor (DMAG) decreased IH formation after arterial injury. It was concluded that 17­DMAG may be utilized as an effective therapy to prevent restenosis after revascularization.

The role of the Vascular Surgery Board in surgical education.

The American Board of Surgery (ABS) has more than 80 years of both direct and indirect involvement in US surgical education, with its primary role being certification of graduates of Accreditation Council for Graduate Medical Education-approved surgical training programs. The ABS's impact on education has been at multiple levels, including the development of the content and administration of qualifying and certifying examinations; original education research based on the Board's unique data sets; and surgical training and education-related initiatives in partnership with multiple regulatory bodies and surgical societies. Within these efforts, by incremental steps, the specialty of vascular surgery attained recognition as a primary specialty of the ABS, and the Vascular Surgery Board of the ABS was established 20 years ago, in 1998. The 2 decades that followed have witnessed significant transformations in the evaluation and treatment of vascular disease, the paradigms for training vascular and endovascular surgeons, and the Vascular Surgery Board has partnered with stakeholder organizations to continually ensure quality education for the evolving vascular surgical workforce. Looking forward, while surgical education remains outside of its primary mission, the ABS and Vascular Surgery Board will continue as key stakeholders and leaders in the complex network of professional societies and training institutions that will guide the evolution of vascular surgery training.

Frailty and Biomarkers of Frailty Predict Outcome in Veterans After Open and Endovascular Revascularization.

BACKGROUND: Frailty predicts poor outcome after vascular surgery. We determined the predictive utility of the modified frailty index (mFI) after first-time revascularization and identified biomarkers of frailty predictive of outcome in veterans with peripheral arterial disease. METHODS: A retrospective study was performed of first-time revascularizations (open surgery [OS] and endovascular surgery [ES]) in male veterans (2003-2016). Preoperative mFI scores were calculated, and serum and nonserum biomarkers of frailty were recorded. The primary endpoint was 2-y incidence of reintervention, amputation, and mortality. Secondary endpoints included 30-day morbidity and readmissions. RESULTS: Four hundred and thirty one patients (OS, n = 188; ES, n = 243), mean age of 66 ± 9 y, and 16 mo of median follow-up were studied. Mean mFI was 0.39 ± 0.16 for OS and 0.38 ± 0.15 for ES (P = 0.43). 30-day complications (adjusted odds ratio, 4.89; 95% confidence interval [CI]: 1.67-14.33) and readmissions (adjusted hazard ratio [aHR] 3.32; 95% CI: 1.16-9.55) were increased in the OS versus ES group when stratified by mFI. Survival analysis showed a correlation between risk of amputation, death, and composite outcome with increasing mFI (P < 0.005) in both groups. Frailty independently predicted major amputation (aHR 2.16; 1.06-4.39), mortality (aHR 2.62; 95% CI: 1.17-5.88), and composite outcome (aHR 1.97; 95% CI: 1.06-3.68) when the groups are combined. Except for absolute neutrophil count, all preoperative lab values correlated with mFI (P < 0.5). Higher albumin was independently associated with lower risk of amputation (aHR: 0.58 [0.36-0.94]) and mortality (aHR: 0.45 [0.25-0.83]); higher hemoglobin predicted limb salvage (aHR 0.7 [0.62-0.84]). CONCLUSIONS: Frailty predicts short- and long-term outcomes after first-time revascularization in veterans. Hypoalbuminemia and anemia are associated with higher mFI and independently predict poor outcome, suggesting albumin and hemoglobin are viable biomarkers of frailty in veterans.

Intraluminal Delivery of Simvastatin Attenuates Intimal Hyperplasia After Arterial Injury.

INTRODUCTION: Oral statins reduce intimal hyperplasia (IH) after arterial injury by only ∼25%. Alternative drug delivery systems have gained attention as carriers for hydrophobic drugs. We studied the effects of simvastatin (free vs hyaluronic acid-tagged polysialic acid-polycaprolactone micelles) on vascular smooth muscle cell (VSMC) migration, VSMC proliferation and intimal hyperplasia. We hypothesized both free and micelle containing simvastatin would inhibit VSMC chemotaxis and proliferation, and local statin treatment would be more effective than oral in reducing IH in rats following carotid balloon injury. METHODS: VSMCs pretreated with free simvastatin (20 minutes or 20 hours) or simvastatin-loaded micelles underwent chemotaxis and proliferation to platelet-derived growth factor. Next, rats that underwent balloon injury of the common carotid artery received statin therapy-intraluminal simvastatin-loaded micelles prior to injury, periadventitial pluronic gel following injury, or combinations of gel, micelle, and oral simvastatin. After 14 days, morphometric analysis determined the -intimal to medial ratio. Findings were compared to controls receiving oral simvastatin or no statin therapy. Statistical analysis was by analysis of variance for the in vitro experiments and a factorial general linear model for the in vivo experiments. RESULTS: The simvastatin-loaded micelles and free simvastatin inhibited VSMC chemotaxis (54%-60%). IH was induced in all injured vessels. Simvastatin in pluronic gel or micelles reduced IH compared to untreated controls (0.208 ± 0.04 or 0.160 ± 0.03 vs 0.350 ± 0.03, respectively); however, neither gel nor simvastatin-loaded micelles were superior to oral statins (0.261 ± 0.03). Addition of oral statins or combining both local therapies did not provide additional benefit. Micelles were the single greatest contributing factor in IH attenuation. CONCLUSIONS: Intraluminally or topically delivered statins reduced IH. The efficacy of single-dose, locally delivered statin alone may lead to novel treatments to prevent IH. The different routes of administration may allow for treatment during endovascular procedures, without the need for systemic therapy.

Fluvastatin inhibits intimal hyperplasia in wild-type but not Thbs1-null mice.

BACKGROUND: Thrombospondin-1 (TSP-1) is functionally important to intimal hyperplasia (IH) development. Statin drugs have beneficial pleiotropic effects, including reduced IH; however, the effect of statins on IH in a TSP-1-independent setting is unknown. HYPOTHESIS: Statins will be less effective in attenuating IH after vascular injury in TSP-1-null (Thbs1-/-) mice compared with wild-type (WT) mice. MATERIALS AND METHODS: Carotid artery ligation was performed on WT and Thbs1-/- mice. Each strain was divided into two groups: no statin control or standard chow containing fluvastatin (10 or 40 mg/kg/d). After 28 d, analysis included morphometric analysis and real-time quantitative reverse transcription polymerase chain reaction on the arteries and enzyme-linked immunosorbent assay on plasma (TSP-1 WT, TSP-2 WT, and Thbs1-/-). Comparisons were made by analysis of variance, with P < 0.05 considered significant. RESULTS: In no statin controls, WT mice had more IH than Thbs1-/- mice (0.46 ± 0.09 versus 0.15 ± 0.04). Fluvastatin reduced IH in the WT (0.46 ± 0.09 versus 0.23 ± 0.06), but not in Thbs1-/- groups (0.15 ± 0.04 versus 0.22 ± 0.07). No difference in IH existed between Thbs1-/- no statin controls and fluvastatin WT and Thbs1-/- groups. Statin dose did not affect IH. TSP-1 plasma levels were increased in fluvastatin WT. TSP-2 levels were decreased in fluvastatin WT and elevated in fluvastatin Thbs1-/-. Fluvastatin had no effect on tissue Thbs1 or Thbs2 gene expression. CONCLUSIONS: TSP-1 is necessary for robust IH after arterial injury. Because fluvastatin had no effect on IH in Thbs1-/-, the data suggest that the statin effect on IH may be largely TSP-1 dependent. Both statins and the presence of TSP-1 affect TSP-1 and TSP-2 plasma levels.

Postoperative conversion disorder.

Conversion disorder is a psychiatric disorder in which psychological stress causes neurologic deficits. A 28-year-old female surgical patient had uneventful general anesthesia and emergence but developed conversion disorder 1 hour postoperatively. She reported difficulty speaking, right-hand numbness and weakness, and right-leg paralysis. Neurologic examination and imaging revealed no neuronal damage, herniation, hemorrhage, or stroke. The patient mentioned failing examinations the day before surgery and discontinuing her prescribed antidepressant medication, leading us to diagnose conversion disorder, with eventual confirmation by neuroimaging and follow-up examinations.

Dyslipidemia Part 2: Review of Dyslipidemia Treatment in Patients With Noncoronary Vascular Disease.

Dyslipidemia is one of the major modifiable risk factors associated with atherosclerotic cardiovascular disease. Appropriate modification of lipid profiles reduces the progression of atherosclerosis in vessel walls across all vascular beds. The management of dyslipidemia has evolved over the last several decades, especially since the discovery of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, also known as statins. Statin use in atherosclerotic heart disease is well described in observational and prospective placebo-controlled studies, citing both lipid-lowering and pleiotropic effects. However, the effect of statins and other lipid-lowering agents on noncoronary arterial beds (the aorta, arteries to the extremities, renal, and carotid arteries) is less understood. This article is part 2 of a 2-part review, with part 1 having focused on lipid metabolism and the downstream effects of lipids on the development of atherosclerosis. The current review (part 2) will discuss trials, retrospective reviews, and observational cohort studies regarding the use of statins and/or other lipid-lowering drugs for primary and secondary prevention of peripheral noncoronary atherosclerotic disease.

Dyslipidemia Part 1--Review of Lipid Metabolism and Vascular Cell Physiology.

Dyslipidemia, more specifically, high-serum low-density lipoproteins and low-serum high-density lipoproteins, are known risk factors for cardiovascular disease. The current clinical treatment of dyslipidemia represents the outcome of a large body of fundamental basic science research on lipids, lipid metabolism, and the effects of different lipids on cellular components of the artery, inflammatory cells, and platelets. In general, lower density lipids activate intracellular pathways to increase local and systemic inflammation, monocyte adhesion, endothelial cell dysfunction and apoptosis, and smooth muscle cell proliferation, resulting in foam cell formation and genesis of atherosclerotic plaque. In contrast, higher density lipids prevent or attenuate atherosclerosis. This article is part 1 of a 2-part review, with part 1 focusing on lipid metabolism and the downstream effects of lipids on the development of atherosclerosis, and part 2 on the clinical treatment of dyslipidemia and the role of these drugs for patients with arterial disease exclusive of the coronary arteries.

Thrombospondin-1 differentially regulates microRNAs in vascular smooth muscle cells.

Thrombospondin-1 (TSP-1) is an important regulator of vascular smooth muscle cell (VSMC) physiology and gene expression. MicroRNAs (microRNA), small molecules that regulate protein translation, have emerged as potent regulators of cell function. MicroRNAs have been shown to be involved in intimal hyperplasia, atherosclerosis, and upregulated in the vasculature in diabetes. The purpose of this study was to identify microRNAs regulated by TSP-1 in vascular smooth muscle cells (VSMCs). Human VSMCs were treated for 6 h with basal media or TSP-1 both supplemented with 0.2% FBS. Cells were then snap frozen and RNA extracted. An Affymetrix GeneChip microRNA array analysis was performed in triplicate on three separate collections. Confirmatory qrtPCR was performed. Data were analyzed by ANOVA or t test, with significance set at p < 0.05. MicroRNAs identified were subjected to KEGG pathway analysis using the DIANA tools miRPath online tool. TSP-1 upregulated 22 microRNAs and downregulated 18 microRNAs in VSMCs (p < 0.05). The most upregulated microRNA was miR-512-3p (45.12 fold). The microRNA most downregulated by TSP-1 was miR-25-5p, which was decreased by 9.61. Of note, five members of the mir-17-92 cluster were downregulated. KEGG analysis revealed that thirty-three cellular signaling pathways were impacted by these microRNAs and that nine pathways were relevant to vascular disease. MicroRNAs regulate protein expression at the level of translation and may represent a significant mechanism by which TSP-1 regulates VSMC function. Several of the microRNAs identified have a role in vascular function. The miR-17-92 cluster family, which was found to exhibit reduced expression in this study, is known to be involved in angiogenesis and vascular function. TSP-1 regulates multiple microRNAs in VSMCs adding a new layer of complexity to TSP-1 regulation of VSMC function.

Endovascular stent graft exclusion of a thoracic arteriovenous malformation in a patient with Cobb syndrome.

Cobb syndrome is a rare neurocutaneous disorder characterized by spinal vascular abnormalities in association with a vascular lesion of the skin at the same metamere. Patients present after the onset of symptoms such as paraplegia, back pain, and, less commonly, fatigue due to heart failure. Available treatment options to date have included neurosurgical resection and endovascular embolization. We present a patient with Cobb syndrome with a progressively symptomatic arteriovenous malformation involving the thoracic vertebrae and left hemithorax, with extensive blood supply from the T3 to T10 intercostal arteries, and demonstrate successful endovascular thoracic stent graft placement and coil embolization.

Dyslipidemia regulates thrombospondin-1-induced vascular smooth muscle cell chemotaxis.

UNLABELLED: Dyslipidemia is a risk factor for intimal hyperplasia (IH). Key to IH is vascular smooth muscle cell (VSMC) migration. Thrombospondin-1 (TSP-1) is a matricellular protein that stimulates VSMC migration. HYPOTHESIS: HDL will inhibit and LDL will augment TSP-1-induced VSMC chemotaxis. VSMC chemotaxis will be inhibited by the HDL moiety, S1P, through the S1PR1 receptor, and augmented by the LDL component, LPA, through the LPAR1 receptor. The goal of this study was to determine the effect of HDL and LDL and their receptors on TSP-1-induced VSMC chemotaxis. For VSMC chemotaxis to TSP-1 cells received the following pretreatments: low (25 µg/ml) or optimal (75 µg/ml) concentration of HDL, S1P, optimal (75 µg/ml) or high (175 µg/ml) concentration of LDL, or LPA. For the receptor studies, VSMCs were transfected with siRNA to S1PR1, S1PR3, LPAR1, LPAR2, LPAR3, or a S1PR2 receptor antagonist. The TSP-1-induced chemotaxis results were (1) HDL (25 µg/ml) or LDL (75 µg/ml) exhibited no effect on chemotaxis; (2) HDL (75 µg/ml) inhibited chemotaxis by 50.9 ± 8 % and S1P by 43.4 ± 11.6 %; (3) LDL (175 µg/ml) augmented chemotaxis by 30 ± 10.4 % and LPA by 25.6 ± 12.3 %; (4) S1PR1 and S1PR3 knockdown and S1PR2 antagonist-treated cells augmented chemotaxis; and (5) LPAR1 and LPAR2 knockdown inhibited and LPAR3 knockdown had no effect on chemotaxis. In conclusion, HDL/S1P inhibits, while LDL/LPA stimulates TSP-1-induced VSMC chemotaxis. The HDL/S1P effect is mediated by the S1PR1-3 receptors. The LDL/LPA effects are mediated by the LPAR1 and LPAR2 receptors, but not LPAR3. Therefore, lipids have significant effects on TSP-1-induced VSMC chemotaxis.

Thrombospondin-1, -2 and -5 have differential effects on vascular smooth muscle cell physiology.

INTRODUCTION: The thrombospondins (TSPs) are matricellular proteins that exert multifunctional effects by binding cytokines, cell-surface receptors and other proteins. TSPs play important roles in vascular pathobiology and are all expressed in arterial lesions. The differential effects of TSP-1, -2, and -5 represent a gap in knowledge in vascular smooth muscle cell (VSMC) physiology. Our objective is to determine if structural differences of the TSPs imparted different effects on VSMC functions critical to the formation of neointimal hyperplasia. We hypothesize that TSP-1 and -2 induce similar patterns of migration, proliferation and gene expression, while the effects of TSP-5 are different. METHODS: Human aortic VSMC chemotaxis was tested for TSP-2 and TSP-5 (1-40 µg/mL), and compared to TSP-1 and serum-free media (SFM) using a modified Boyden chamber. Next, VSMCs were exposed to TSP-1, TSP-2 or TSP-5 (0.2-40 µg/mL). Proliferation was assessed by MTS assay. Finally, VSMCs were exposed to TSP-1, TSP-2, TSP-5 or SFM for 3, 6 or 24 h. Quantitative real-time PCR was performed on 96 genes using a microfluidic card. Statistical analysis was performed by ANOVA or t-test, with p < 0.05 being significant. RESULTS: TSP-1, TSP-2 and TSP-5 at 20 µg/mL all induce chemotaxis 3.1 fold compared to serum-free media. TSP-1 and TSP-2 induced proliferation 53% and 54% respectively, whereas TSP-5 did not. In the gene analysis, overall, cardiovascular system development and function is the canonical pathway most influenced by TSP treatment, and includes multiple growth factors, cytokines and proteases implicated in cellular migration, proliferation, vasculogenesis, apoptosis and inflammation pathways. CONCLUSIONS AND RELEVANCE: The results of this study indicate TSP-1, -2, and -5 play active roles in VSMC physiology and gene expression. Similarly to TSP-1, VSMC chemotaxis to TSP-2 and -5 is dose-dependent. TSP-1 and -2 induces VSMC proliferation, but TSP-5 does not, likely due conservation of N-terminal domains in TSP-1 and -2. In addition, TSP-1, -2 and -5 significantly affect VSMC gene expression; however, little overlap exists in the specific genes altered. This study further delineates TSP-1, -2 and -5's contributions to processes related to VSMC physiology.

Statins and nitric oxide donors affect thrombospondin 1-induced chemotaxis.

BACKGROUND: Thrombospondin 1 (TSP-1) induces vascular smooth muscle cell (VSMC) migration and intimal hyperplasia. Statins and nitric oxide (NO) donors decrease intimal hyperplasia. We previously showed that statins (long-term exposure) and NO donors inhibit TSP-1-induced VSMC chemotaxis. HYPOTHESES: (1) Pretreatment with short-term statin will inhibit TSP-1-induced VSMC chemotaxis and (2) NO donors will enhance statin inhibition of TSP-1-induced or platelet-derived growth factor (PDGF)-induced VSMC chemotaxis. METHODS: We examined these treatment effects on TSP-1-induced VSMC chemotaxis: (1) long-term (20 hours) versus short-term (20 minutes) pravastatin, (2) diethylenetriamine NONOate (DETA/NO) or S-nitroso-N-acetylpenicillamine (SNAP) in combination with pravastatin, and (3) comparison of TSP-1 to PDGF as a chemoattractant. RESULTS: Pravastatin (long term or short term) inhibited TSP-1-induced chemotaxis. Diethylenetriamine NONOate and SNAP impeded statin inhibition of TSP-1-induced chemotaxis. Platelet-derived growth factor and TSP-1 had opposite effects on DETA/NO-pravastatin treatment. CONCLUSION: Short-term statin pretreatment inhibited TSP-1-induced VSMC chemotaxis, suggesting a pleiotropic effect. High-dose NO reversed statin inhibition of TSP-1-induced chemotaxis, suggesting NO and statin combination therapies warrant further study.

Thrombospondin-1-induced vascular smooth muscle cell migration and proliferation are functionally dependent on microRNA-21.

OBJECTIVES: Thrombospondin-1 (TSP-1) is a matricellular glycoprotein released from platelets at sites of arterial injury and is important in neointima development after balloon angioplasty. MicroRNAs are small noncoding RNAs that function by binding target gene mRNA and inhibiting protein translation. MicroRNA-21 (miR-21) is up-regulated after angioplasty, and inhibition of miR-21 leads to decreased intimal hyperplasia. In this study, we examined the effects of miR-21 inhibition on vascular smooth muscle cell (VSMC) processes. METHODS: VSMCs were exposed to TSP-1 and miR-21 inhibitor for 20 minutes. TSP-1-induced migration was assessed with a modified Boyden microchemotaxis chamber and proliferation with calcein-AM fluorescence. Phosphorylated extracellular signaling kinase (ERK) 1/2 expression was determined by Western Blot and densitometry. Quantitative real-time polymerase chain reaction for TSP-1, hyaluronic acid synthase 2 (HAS2), and transforming growth factor beta 2 (TGFß2) was performed. Statistical analysis was performed with analysis of variance (P < .05). RESULTS: Inhibition of miR-21 blocked TSP-1-induced VSMC migration, proliferation, and ERK 1/2 phosphorylation (P < .05) and had no effect on TSP-1-stimulated expression of genes for TSP-1, HAS2, or TGFß2 (P > .05). CONCLUSION: Acute inhibition of miR-21 led to a decrease in VSMC migration and proliferation caused by TSP-1. The decrease in TSP-1's activation of ERK 1/2 after acute miR-21 inhibition indicates an active role for miR-21 in TSP-1's cell signaling cascade. No effect on TSP-1-induced expression of the pro-stenotic genes thbs1, tgfb2, or has2, occurred after acute miR-21 inhibition. These data indicate that miR-21 directly modulates cell function and signaling pathways in ways other than inhibition of protein translation.

Correlation of hemoglobin A1C level with surgical outcomes: Can tight perioperative glucose control reduce infection and cardiac events?

"Optimal" control of serum glucose levels is an important principle in the successful management of diabetes mellitus. Conversely, poorly controlled serum glucose levels are associated with negative sequelae, including accelerated progression of cardiovascular disease, increased mortality, and increased perioperative complications. The importance of glycemic control as a part of appropriate perioperative management is reviewed and target values are recommended.

Thrombospondin-1-induced smooth muscle cell chemotaxis and proliferation are dependent on transforming growth factor-ß2 and hyaluronic acid synthase.

Angioplasty causes local vascular injury, leading to the release of thrombospondin-1 (TSP-1), which stimulates vascular smooth muscle cell (VSMC) migration and proliferation, important steps in the development of intimal hyperplasia. Transforming growth factor beta 2 (TGF-ß2) and hyaluronic acid synthase (HAS) are two pro-stenotic genes upregulated in VSMCs by TSP-1. We hypothesized that inhibition of TGF-ß2 or HAS would inhibit TSP-1-induced VSMC migration, proliferation, and TSP-1 signaling. Our data demonstrate that Inhibition of either TGF-ß2 or HAS inhibited TSP-1-induced VSMC migration and proliferation. Activation of ERK 1 was decreased by TGF-ß2 inhibition and unaffected by HAS inhibition. TGF-ß2 and HAS are not implicated in TSP-1-induced thbs1 expression, while they are each implicated in TSP-1-induced expression of their own gene. In summary, TSP-1-induced VSMC migration and proliferation rely on intact TGF-ß2 signaling and HAS function. TSP-1 activation of ERK 1 is dependent on TGF-ß2. These data further expand our understanding of the complexity of TSP-1 cellular signaling and the involvement of TGF-ß2 and HAS.