High-Density Lipoproteins, Endothelial Function, and Mendelian Randomization

Worst spasticity in patients post-stroke associated with MNSOD ALA16VAL polymorphism and interleukin-1β

The MnSOD Ala16Val single nucleotide polymorphism (SNP) has shown to be associated to risk factors of several metabolic and vascular diseases. However, little is known about interaction between MnSOD Ala16Val SNP in stroke, a frequent neurologic disease that involves clinic manifestations such as motor deficits and spasticity. In this sense, we decided to investigate the relationship between MnSOD Ala16Val SNP with spasticity in stroke and also its influence on interleukin levels, BDNF, and glycolipid parameters. Eighty post-stroke subjects and 80 healthy controls were investigated. We showed a higher spasticity, levels of total cholesterol, LDL, IL-1β, IL-6, and INF-γ in VV post-stroke group. Interesting, we found a correlation between IL-1β levels and spasticity in VV post-stroke. Triglycerides, glucose levels and caspases (1 and 3) activation were significantly higher, as well as BDNF levels were lower in VV and AV post-stroke. DNA damage was higher in post-stroke group. Thus, we can suggest that the V allele has a worse glycolipid profile, which would facilitate changes in neurovascular homeostasis. These events associated with an increase in inflammatory markers and a reduction in BDNF can contribute with the stroke and a worse clinical evolution in relation to spasticity in patients with VV genotype.

Recombinant LCAT (Lecithin:Cholesterol Acyltransferase) Rescues Defective HDL (High-Density Lipoprotein)-Mediated Endothelial Protection in Acute Coronary Syndrome

Objective- Aim of this study was to evaluate changes in LCAT (lecithin:cholesterol acyltransferase) concentration and activity in patients with an acute coronary syndrome, to investigate if these changes are related to the compromised capacity of HDL (high-density lipoprotein) to promote endothelial nitric oxide (NO) production, and to assess if rhLCAT (recombinant human LCAT) can rescue the defective vasoprotective HDL function. Approach and Results- Thirty ST-segment-elevation myocardial infarction (STEMI) patients were enrolled, and plasma was collected at hospital admission, 48 and 72 hours thereafter, at hospital discharge, and at 30-day follow-up. Plasma LCAT concentration and activity were measured and related to the capacity of HDL to promote NO production in cultured endothelial cells. In vitro studies were performed in which STEMI patients' plasma was added with rhLCAT and HDL vasoprotective activity assessed by measuring NO production in endothelial cells. The plasma concentration of the LCAT enzyme significantly decreases during STEMI with a parallel significant reduction in LCAT activity. HDL isolated from STEMI patients progressively lose the capacity to promote NO production by endothelial cells, and the reduction is related to decreased LCAT concentration. In vitro incubation of STEMI patients' plasma with rhLCAT restores HDL ability to promote endothelial NO production, possibly related to significant modification in HDL phospholipid classes. Conclusions- Impairment of cholesterol esterification may be a major factor in the HDL dysfunction observed during acute coronary syndrome. rhLCAT is able to restore HDL-mediated NO production in vitro, suggesting LCAT as potential therapeutic target for restoring HDL functionality in acute coronary syndrome.

Trials and Tribulations of CETP Inhibitors

The development of CETP (cholesteryl ester transfer protein) inhibitors has had a long and difficult course with 3 compounds failing in phase III clinical trials. Finally, the REVEAL (Randomized Evaluation of the Effects of Anacetrapib through Lipid modification) trial has shown that the CETP inhibitor anacetrapib decreased coronary heart disease when added to statin therapy. Although the result is different to earlier studies, this is likely related to the size and duration of the trial. The benefit of anacetrapib seems to be largely explained by lowering of non-HDL-C (high-density lipoprotein cholesterol), rather than increases in HDL-C. Although the magnitude of benefit for coronary heart disease appeared to be moderate, in part this may have reflected aspects of the trial design. Anacetrapib treatment was associated with a small increase in blood pressure, but was devoid of major side effects and was also associated with a small reduction in diabetes mellitus. Treatment with CETP inhibitors, either alone or in combination with statins, could provide another option for patients with coronary disease who require further reduction in LDL (low-density lipoprotein) and non-HDL-C.