Correlation between endothelial cell apoptosis and SIRT3 gene expression in atherosclerosis rats

OBJECTIVE

To investigate the correlation between the endothelial cell apoptosis and sirtuin-3 (SIRT3) gene expression in atherosclerosis (AS) rats.

MATERIALS AND METHODS

The AS model in rats was established through the high-fat diet. A total of 12 rats fed normally were enrolled as the control group, while 12 rats fed with high-fat diet were enrolled as the experimental group. After the experiment, the aortic tissues of rats were collected, and the relative area of the arterial plaque (total area of plaque/total area of the vessel) was measured via oil red O staining. The serum was collected to detect the levels of blood lipid, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). Moreover, the expression levels of SIRT3 and apoptotic genes were determined via Reverse Transcription-Polymerase Chain Reaction (RT-PCR), Western blotting and immunohistochemistry (IHC), respectively. The apoptosis was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining.

RESULTS

The area of aortic plaque in the experimental group [(36.15±9.52)%] was significantly larger than that in the control group [(11.62±3.25)%] (p<0.01). Compared with those in the control group, the serum TC, TG and LDL-C levels were significantly increased in the experimental group, while the HDL-C level was significantly decreased (p<0.05). Compared with those in the control group, the mRNA and protein expression levels of SIRT3 in the aorta of rats markedly declined in the experimental group (p<0.05), while Caspase-3 and Caspase-9 expressions were significantly increased (p<0.05), respectively. The results of TUNEL staining revealed that the apoptosis in the aorta of rats in the experimental group was remarkably higher than that in the control group (p<0.05).

CONCLUSIONS

The expression of SIRT3 is deleted in the aorta of AS rats and closely related to the apoptosis. SIRT3 may serve as a potential target for the treatment of AS.

The effect of hyperthermic treatment on electroencephalographic recovery after interruption of respiration in rats

Electroencephalography (EEG) was utilized for investigating the effect of hyperthermia followed by apneic hypoxia in rats. They were heated whole-bodily to 41 degrees C for 15 min under the control of an artificial rodent ventilator, after drug-induced generalized paralysis. A transcutaneous oxygen saturation monitor was applied to detect the hypoxic condition. EEG was monitored with bipolar needle electrodes. The 72-kDa heat-shock protein (HSP72) in brain was analyzed by sodium dodecyl sulfate-polyacrylamide electrophoresis, followed by immunostaining with an anti-HSP72 antibody. There was no difference in the time interval from onset of apneic hypoxia to flat EEG between the hyperthermic and control groups, but cortical electrical activity appeared earlier in the hyperthermia group than the control group, after 90 s of ventilation interruption. The cardiac function did not change in the two groups. The HSP72 synthesis significantly increased in the brain of the rats with hyperthermic treatment.

[Lysosomal enzyme activity of cultured fetal cells in Chinese and its clinical application]

Lysosomal storage diseases (LSD) are caused by deficient activity of specific lysosomal enzymes. Early diagnosis and selective termination is still the trend of therapy. The purpose of this study was to establish an assay system and investigate the reference range of lysosomal enzyme activity of cultured fetal cells in the Chinese population. Seventy amniotic fluid and 9 chorionic villi samples were collected and cultured in this study. Enzyme activity assay was done by synthesized 4-Mu-binded substrates. The activity was expressed as nmol/mg protein/hour. In cultured amniotic cells, the results showed 14-138 of alpha-glucosidase, 8-133 of alpha-galactosidase, 32-470 of alpha-mannosidase, 101-1121 of alpha-fucosidase, 106-1321 of beta-galactosidase, 15-268 of beta-glucosidase, 11-279 of beta-glucuronidase, 101-1193 of Hexosaminidase A, and 886-6204 of N-acetyl-alpha-glucosaminidase. In cultured chorionic villi samples, it showed 22-335 of alpha-glucosidase, 31-230 of alpha-galactosidase, 47-250 of alpha-mannosidase, 35-218 of alpha-fucosidase, 49-934 of beta-galactosidase, 34-329, of beta-glucosidase, 57-379 of beta-glucuronidase, and 328-3412 of Hexosaminidase A. The enzyme activity was not correlated with the gestation age when sample was obtained. Furthermore, there was no statistical significance among the range of amniotic cells, chorionic villi samples, skin fibroblasts and peripheral leukocytes for each enzyme studied. It is suggested that the synthesis of lysosomal enzymes has been mature since the early fetal state, and the samples obtained as early as 8 weeks of gestation age can be used for early diagnosis of lysosomal storage diseases.