Serum Non-Esterified Fatty Acids, Carotid Artery Intima-Media Thickness and Flow-Mediated Dilation in Older Adults: The Cardiovascular Health Study (CHS)

Association of serum CTRP4 levels with vascular endothelial function in patients with type 2 diabetes mellitus: CTRP4 ameliorating inflammation, proliferation and migration in human umbilical vein endothelial cells

OBJECTIVE

We investigated the correlation between serum C1q/TNF-related protein 4 (CTRP4) level and flow-mediated dilation (FMD) in patients with type 2 diabetes mellitus (T2DM), and evaluated the biological effects of CTRP4 on human umbilical vein endothelial cells (HUVECs).

METHODS

A group of 165 patients diagnosed with T2DM were included in this study. Endothelial function was measured with the examination of brachial artery FMD. ELISA kit was used to measure the levels of CTRP4 in serum. HUVECs were stimulated with recombinant CTRP4 protein to assess its biological functions.

RESULTS

The levels of CTRP4 showed a significant variation among three groups based on FMD tertiles (p = 0.001). What's more, FMD had a significant difference among three CTRP4 tertile groups (p < 0.05) and was negatively related to serum CTRP4 levels (r = -0.270, p < 0.001). In T2DM patients, logistic regression analysis demonstrated that CTRP4 was the primary influence factor of low FMD (p < 0.01). In receiver operating characteristic curve analysis, the area under the curve of CTRP4 for predicting low FMD was 0.66 (95%CI 0.58-0.75). When stimulated HUVECs with recombinant CTRP4 protein, we found that CTRP4 could concentration-dependently ameliorate proliferation and migration of HUVECs in wounding healing and transwell assay. This protein could also decrease the expression of IL-6 and TNF-α and promote the release of NO in HUVEC supernatants, with suppression of NF-κB and STAT3 phosphorylation.

CONCLUSIONS

Serum CTRP4 concentrations were negatively associated with FMD. CTRP4 alleviated proliferation, migration and inflammation in HUVECs through the suppression of NF-κB and STAT3 signaling pathways.

Fatty acids act on vascular endothelial cells and influence the development of cardiovascular disease

Endothelial cells (ECs) maintain the health of blood vessels and prevent the development of cardiovascular disease (CVD). Free saturated fatty acids (FAs) induce EC damage and increase the risk of CVD by promoting arteriosclerosis. Conversely, polyunsaturated FAs (PUFAs), such as docosahexaenoic acid, are thought to suppress EC damage induced during the early stages of CVD. This review describes the effects of multiple dietary FAs on EC disorders involved in the development of CVD. The roles of FAs in atherosclerosis and CVD were analyzed by evaluating articles published in PubMed, Science Direct, and Web of Science. Saturated FAs were found to induce EC damage by reducing the production and action of EC-derived nitric oxide. Oxidative stress, inflammation, and the renin-angiotensin system were found to be involved in EC disorder. Furthermore, n-3 PUFAs were found to reduce EC dysfunction and prevent the development of EC disorder. These results indicate that FAs may affect EC failure induced during the early stages of CVD and reduce the risk of developing the disease.

Conjugated Linoleic Acids Have Anti-Inflammatory Effects in Cultured Endothelial Cells

Conjugated linoleic acid (CLA) isomers may have a role in preventing atherosclerosis through the modulation of inflammation, particularly of the endothelium. However, whether low concentrations of CLAs are able to affect basal unstimulated endothelial cell (EC) responses is not clear. The aim of this study was to evaluate the effects of two CLAs (cis-9, trans-11 (CLA9,11) and trans-10, cis-12 (CLA10,12)) on the basal inflammatory responses by ECs. EA.hy926 cells (HUVEC lineage) were cultured under standard conditions and exposed to individual CLAs for 48 h. Both CLAs were incorporated into ECs in a dose-dependent manner. CLA9,11 (1 μM) significantly decreased concentrations of MCP-1 (p < 0.05), IL-6 (p < 0.05), IL-8 (p < 0.01) and RANTES (p < 0.05) in the culture medium. CLA10,12 (10 μM) decreased the concentrations of MCP-1 (p < 0.05) and RANTES (p < 0.05) but increased the concentration of IL-6 (p < 0.001). At 10 μM both CLAs increased the relative expression of the NFκβ subunit 1 gene (p < 0.01 and p < 0.05, respectively), while decreasing the relative expression of PPARα (p < 0.0001), COX-2 (p < 0.0001) and IL-6 (p < 0.0001) genes. CLA10,12 increased the relative expression of the gene encoding IκK-β at 10 μM compared with CLA9,11 (p < 0.05) and increased the relative expression of the gene encoding IκBα at 1 and 10 μM compared with linoleic acid (both p < 0.05). Neither CLA affected the adhesion of monocytes to ECs. These results suggest that low concentrations of both CLA9,11 and CLA10,12 have modest anti-inflammatory effects in ECs. Thus, CLAs may influence endothelial function and the risk of vascular disease. Nevertheless, at these low CLA concentrations some pro-inflammatory genes are upregulated while others are downregulated, suggesting complex effects of CLAs on inflammatory pathways.

Increasing circulating ESM-1 and adhesion molecules are associated with earlystage atherosclerosis in OSA patients:A cross-sectional study

BACKGROUND

There are increasing evidences for a direct relationship between the vascular system and obstructive sleep apnea (OSA). The aim of this study was to investigate the relationship between circulating endothelial cell specific molecule-1 (ESM-1), adhesion molecules and subclinical atherosclerosis in patients with OSA.

METHODS

This was a cross-sectional study in which 161 patients with OSA and 56 controls were recruited. Demographic data, biochemical and polysomnography parameters were collected. We used a powerful high-throughput Multiplex Immunobead Assay technique to simultaneously test plasm levels of ESM-1, P-selectin, E-selectin, L-selectin, inter-cellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1). Carotid intima-media thickness (CIMT) were measured as parameters of vascular endothelial dysfunction and early atherosclerosis.

RESULTS

Increasing circulating levels of ESM-1, P-selectin, E-selectin, L-selectin, ICAM-1 and VCAM-1 were found increased in patients with OSA (all P &lt; 0.001). Furthermore, OSA patients exhibited increased CIMT than controls (P &lt; 0.05). Multivariate linear analysis indicated that elevated ESM-1, P-Selectin, E-selectin, and L-selectin levels were associated with AHI (all P &lt; 0.05). Moreover, multivariate analysis showed that increasing ESM-1, VCAM-1, P-Selectin, and L-selectin were significantly associated with thick CIMT in OSA patients (all P &lt; 0.05).

CONCLUSIONS

Increased circulating ESM-1 and adhesion molecules associated with thick CIMT in OSA, which is a marker of subclinical atherosclerosis. Strict attention to monitor circulating ESM-1 and adhesion molecules is necessary for early detection of subclinical atherosclerosis in OSA patients.