Overexpression of HSP27 in cultured human aortic smooth muscular cells reduces apoptosis induced by low-frequency and low-energy ultrasound by inhibition of an intrinsic pathway.

We investigated in vitro the effect of low-frequency and low-energy ultrasound (LFLEU) on apoptosis of an overexpressed HSP27 human aortic smooth muscle cell (HASMC) line. A frequency of 42.6 kHz was used in all experiments. HASMC were exposed to ultrasound and cell viability was evaluated by MTT reduction. Overexpressed HSP27-HASMC was constructed on a pcDNA3.1 vector. Apoptosis was determined 24 h after treatment by flow cytometry; gene display was evaluated with Affimax chips, and HSP27 mRNA and protein expression levels were measured by RT-PCR and Western blotting. The apoptosis rate (at 30 s) was significantly lower in HASMC transfected with HSP27 (7.14 ± 1.73%), compared with cells transfected with a mock plasmid (17.31 ± 2.72%) or a control group (14.23 ± 2.77%), indicating a protective function for apoptosis induced by LFLEU. Gene display analysis showed that caspase-9 expression in HSP27 cell lines was downregulated and caspase-3 upregulated. However, RT-PCR and Western blotting analysis indicated that both caspase-9 and caspase-3 were inhibited at both the mRNA and protein levels. We suggest that overexpressed HSP27 is capable of protecting the LFLEU from apoptosis and that the pathway for this protection is via downregulated caspase-9 and caspase-3 expression.

Colombian study to assess the use of noninvasive determination of endothelium-mediated vasodilatation (CANDEV). Normal values and factors associated.

The endothelium plays a critical role in vascular homeostasis. Recently, a noninvasive method has been developed to assess flow mediated vasodilatation of the brachial artery (FMD). This test is remarkably stable overtime but no clear set of normal values has been developed. The purposes of our study were to evaluate the accuracy and reproducibility and to identify a set of normal values of FMD. We included 253 normotensive healthy volunteers from three Colombian cities (mean age: 38.2 years; 33% were women). All subjects underwent ultrasound evaluation of endothelial and smooth muscle function. Flow mediated vessel diameter change was measured by two independent observers. The interobserver Lin's concordance correlation coefficient was 0.88% (95% CI: 0.82, 0.94) and there was no evidence of systematic difference between the two measurements (mean difference of -0.30% with limits of agreement of -4.48 to 3.87). Mean %FMD was 11.98% (95% CI: 11.36, 12.61), 13.32% (95% CI: 12.39, 14.25) in women and 11.32% (95% CI: 10.52, 12.13) in men. Subjects with no cardiovascular risk factors had a mean %FMD of 13.74% (95% CI: 13.14, 14.35), in contrast to a mean of only 7.40% (95% CI: 4.33, 9.91) in those with at least one risk factor. A %FMD cut point of 10.4 had a sensitivity of 71.2% and an specificity of 77.2% to identify subjects with at least one cardiovascular risk factor. Using this cut point, endothelial dysfunction was 3.13 times more frequent in subjects with than in subjects without cardiovascular risk factors (95% CI: 2.30, 4.25). In addition, obesity, smoking and hypercholesterolemia were the modifiable risk factors with largest independent significant reduction effects on %FMD. FMD measurements can be made with high accuracy and precision, and a cut point of 10.4% is useful to discriminate between subjects with and without cardiovascular risk factors, and can be recommended as a screening test for the detection of patients at risk of CVD.