Role of acyl-coenzyme A: cholesterol transferase 1 (ACAT1) in retinal neovascularization.

BACKGROUND: We have investigated the efficacy of a new strategy to limit pathological retinal neovascularization (RNV) during ischemic retinopathy by targeting the cholesterol metabolizing enzyme acyl-coenzyme A: cholesterol transferase 1 (ACAT1). Dyslipidemia and cholesterol accumulation have been strongly implicated in promoting subretinal NV. However, little is known about the role of cholesterol metabolism in RNV. Here, we tested the effects of inhibiting ACAT1 on pathological RNV in the mouse model of oxygen-induced retinopathy (OIR). METHODS: In vivo studies used knockout mice that lack the receptor for LDL cholesterol (LDLR-/-) and wild-type mice. The wild-type mice were treated with a specific inhibitor of ACAT1, K604 (10 mg/kg, i.p) or vehicle (PBS) during OIR. In vitro studies used human microglia exposed to oxygen-glucose deprivation (OGD) and treated with the ACAT1 inhibitor (1 µM) or PBS. RESULTS: Analysis of OIR retinas showed that increased expression of inflammatory mediators and pathological RNV were associated with significant increases in expression of the LDLR, increased accumulation of neutral lipids, and formation of toxic levels of cholesterol ester (CE). Deletion of the LDLR completely blocked OIR-induced RNV and significantly reduced the AVA. The OIR-induced increase in CE formation was accompanied by significant increases in expression of ACAT1, VEGF and inflammatory factors (TREM1 and MCSF) (p < 0.05). ACAT1 was co-localized with TREM1, MCSF, and macrophage/microglia makers (F4/80 and Iba1) in areas of RNV. Treatment with K604 prevented retinal accumulation of neutral lipids and CE formation, inhibited RNV, and decreased the AVA as compared to controls (p < 0.05). The treatment also blocked upregulation of LDLR, ACAT1, TREM1, MCSF, and inflammatory cytokines but did not alter VEGF expression. K604 treatment of microglia cells also blocked the effects of OGD in increasing expression of ACAT1, TREM1, and MCSF without altering VEGF expression. CONCLUSIONS: OIR-induced RNV is closely associated with increases in lipid accumulation and CE formation along with increased expression of LDLR, ACAT1, TREM1, and MCSF. Inhibiting ACAT1 blocked these effects and limited RNV independently of alterations in VEGF expression. This pathway offers a novel strategy to limit vascular injury during ischemic retinopathy.

Diagnosis of Statin-Induced Necrotizing Myopathy: Contribution of Anti-HMGCR Antibodies.

Over the last few years, several cases of statin-induced necrotizing myopathy have been described. This myopathy is characterized by the necrosis of muscle fibers and the presence of anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) antibodies. Although the diagnosis of myopathies relies on muscle biopsy, which is considered the gold-standard, the search for autoantibodies has proved to be an essential contribution to the diagnosis of immune-mediated myopathies. The detection of anti-HMGCR antibodies in the patient's serum can be performed by enzyme immunoassays, and more recently, by imunofluorescence. As for the latter, the detection of anti-HMGCR antibodies is performed on tissue sections by indirect immunofluorescence and is characterized by a typical fluorescence pattern called "HMGCR Associated Liver IFL Pattern". The authors present two case reports that show the importance of diagnosing statin-induced necrotizing myopathy as quickly as possible and the contribution of anti-HMGCR antibody detection for the diagnosis.

Nos últimos anos foram descritos vários casos de miopatia necrotizante induzida por estatinas. Esta miopatia caracteriza-se por necrose das fibras musculares e pela presença de anticorpos anti-3-hidroxi-3-metilglutaril-coenzima A redutase (anti-HMGCR). Apesar do diagnóstico das miopatias depender da biópsia muscular, considerada o gold-standard, a pesquisa dos auto-anticorpos tem-se revelado uma contribuição fundamental para o diagnóstico das miopatias imuno-mediadas. A pesquisa dos anticorpos anti-HMGCR no soro do doente pode ser efetuada por recurso a imunoensaios enzimáticos e mais recentemente foi descrita a possibilidade da sua deteção por imunofluorescência. Neste caso, a pesquisa de anticorpos anti-HMGCR é efetuada em seções de tecido, por imunofluorescência indireta e caracteriza-se pela deteção de um padrão de fluorescência típico denominado "HMGCR Associated Liver IFL Pattern". Os autores apresentam dois casos-clínicos que evidenciam não só a importância de diagnosticar o mais rapidamente possível a miopatia necrotizante induzida por estatinas como também a contribuição da deteção de anticorpos anti-HMGCR para o diagnóstico desta miopatia.

Efficacy and safety of coenzyme A versus fenofibrate in patients with hyperlipidemia: a multicenter, double-blind, double-mimic, randomized clinical trial.

Background: We investigated the lipid-lowering efficacy and safety of coenzyme A (CoA) versus fenofibrate in Chinese patients with moderate dyslipidemia.Methods: A total of 417 subjects (aged 18-75 years) diagnosed with moderate dyslipidemia (triglyceride 2.3-6.5 mmol/L) from 13 large cardiovascular centers in China were recruited and randomly divided into a fenofibrate group (n = 207), which received 200 mg of fenofibrate orally once daily, and a CoA group (n = 210), which received 400 mg of CoA orally once a day. Blood lipoproteins, liver and renal function, creatine kinase, and blood glucose were measured at baseline, and after 4 and 8 weeks of treatment.Results: The baseline triglyceride (TG) level in the fenofibrate group and the CoA group was 3.39 ± 0.99 mmol/L and 3.60 ± 1.11 mmol/L, respectively. After treatment for 4 and 8 weeks with fenofibrate, TG was reduced by 31.62% and 33.13%. In the CoA group, TG was reduced by 17.29% and 23.80%. Compared with baseline, total cholesterol (TC) was significantly decreased in both groups after either 4 or 8 weeks of treatment (p < .05). CoA increased high-density lipoprotein cholesterol (HDL-C) after 4 weeks of treatment, whereas it had no significant effect on HDL-C after 8 weeks of treatment. Low-density lipoprotein cholesterol (LDL-C) was not modified in either group. The incidence of side effects was significantly lower in the CoA group compared with the fenofibrate group (p < .05).Conclusions: Compared with fenofibrate, CoA has less effect on reducing plasma TG levels in subjects with moderate dyslipidemia. However, it has fewer adverse effects.

Efficacy and tolerability of coenzyme A vs pantethine for the treatment of patients with hyperlipidemia: A randomized, double-blind, multicenter study.

BACKGROUND: New, safer, and more effective agents to treat hyperlipidemia and thereby prevent cardiovascular events are under research. OBJECTIVE: To evaluate the lipid-lowering effects and safety of a natural hypolipidemic compound, coenzyme A (CoA) capsule, in Chinese patients with moderate dyslipidemia, compared with pantethine. METHODS: Overall, 216 subjects (124 males and 92 females; age, 18-75 years) with moderate dyslipidemia (triglyceride [TG], 2.3-6.5 mmol/L) were randomly divided into 2 groups administered CoA 400 U/d (n = 111) or pantethine 600 U/d (n = 105). Blood lipoproteins, liver and renal function, blood glucose, and complete blood count were measured at baseline and after 4- and 8-week treatment. RESULTS: TG reduction was 26.0% with CoA and 17.4% with pantethine after 4 weeks and 33.3% and 16.5% after 8 weeks; compared with baseline, the reduction was significant (P < .01) in both groups. The difference between the 2 groups was significant at both 4 weeks (P = .0413) and 8 weeks (P < .001). Compared with baseline, total cholesterol and non-high-density lipoprotein cholesterol (non-HDL-C) were reduced, whereas HDL-C was increased with CoA after 8 weeks (all P < .05). Compared with pantethine, total cholesterol (P = .026) and non-HDL-C (P = .005) were significantly reduced after 8 weeks of CoA treatment. There was no statistical difference in low-density lipoprotein cholesterol or HDL-C between the 2 groups (P > .05) and no difference in blood glucose, hepatic or renal function, myopathy, or gastrointestinal tract symptoms. CONCLUSIONS: CoA can improve TG and other lipoprotein parameters to a greater extent than pantethine in moderate dyslipidemia, with no obvious adverse effects.

Efficacy and tolerability of adding coenzyme A 400 U/d capsule to stable statin therapy for the treatment of patients with mixed dyslipidemia: an 8-week, multicenter, double-blind, randomized, placebo-controlled study.

BACKGROUND: Patients with mixed hyperlipidemia usually are in need of combination therapy to achieve low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) target values for reduction of cardiovascular risk. This study investigated the efficacy and safety of adding a new hypolipidemic agent, coenzyme A (CoA) to stable statin therapy in patients with mixed hyperlipidemia. METHODS: In this multi-center, 8-week, double-blind study, adults who had received ≥8 weeks of stable statin therapy and had hypertriglyceridemia (TG level at 2.3-6.5 mmol/L) were randomized to receive CoA 400 U/d or placebo plus stable dosage of statin. Efficacy was assessed by the changes in the levels and patterns of lipoproteins. Tolerability was assessed by the incidence and severity of adverse events (AEs). RESULTS: A total of 304 patients with mixed hyperlipidemia were randomized to receive CoA 400 U/d plus statin or placebo plus statin (n = 152, each group). After treatment for 8 weeks, the mean percent change in TG was significantly greater with CoA plus statin compared with placebo plus statin (-25.9% vs -4.9%, respectively; p = 0.0003). CoA plus statin was associated with significant reductions in TC (-9.1% vs -3.1%; p = 0.0033), LDL-C (-9.9% vs 0.1%; p = 0.003), and non- high-density lipoprotein cholesterol (-13.5% vs -5.7%; p = 0.0039). There was no significant difference in the frequency of AEs between groups. No serious AEs were considered treatment related. CONCLUSIONS: In these adult patients with persistent hypertriglyceridemia, CoA plus statin therapy improved TG and other lipoprotein parameters to a greater extent than statin alone and has no obviously adverse effect. TRIAL REGISTRATION: Current Controlled Trials ClinicalTrials.gov ID NCT01928342.