Research on the correlation between activating transcription factor 3 expression in the human coronary artery and atherosclerotic plaque stability.

BACKGROUND: Activating transcription factor 3 (ATF3) is an early response gene that is activated in response to atherosclerotic stimulation and may be an important factor in inhibiting the progression of atherosclerosis. In this study, we directly measured the expression of ATF3 and inflammatory factors in human coronary atherosclerotic plaques to examine the relationship between ATF3 expression, inflammation and structural stability in human coronary atherosclerotic plaques. METHODS: A total of 68 coronary artery specimens were collected from the autopsy group, including 36 cases of sudden death from coronary heart disease (SCD group) and 32 cases of acute death caused by mechanical injury with coronary atherosclerosis (CHD group). Twenty-two patients who had no coronary heart disease were collected as the control group (Con group). The histological structure of the coronary artery was observed under a light microscope after routine HE staining, and the intimal and lesion thicknesses, thickness of the fibrous cap, thickness of necrosis core, degree of lumen stenosis were assessed by image analysis software. Western blotting and immunohistochemistry were used to measure the expression and distribution of ATF3, inflammatory factors (CD45, IL-1ß, TNF-α) and matrix metalloproteinase-9 (MMP-9) and vascular cell adhesion molecule 1 (VCAM1) in the coronary artery. The Pearson correlation coefficient was used to analyse the correlation between ATF3 protein expression and inflammatory factors and between ATF3 protein expression and structure-related indexes in the lesion group. RESULTS: Compared with those in the control group, the intima and necrotic core in the coronary artery were thickened, the fibrous cap became thin and the degree of vascular stenosis was increased in the lesion group, while the intima and necrotic core became thicker and the fibrous cap became thinner in the SCD group than in the CHD group (P < 0.05). There was no or low expression of ATF3, inflammatory factors, VCAM1 and MMP-9 in the control group, and the expression of inflammatory factors, VCAM1 and MMP-9 in the SCD group was higher than that in CHD group, while the expression of ATF3 in the SCD group was significantly lower than that in CHD group (P < 0.05). In the lesion group, the expression of ATF3 was negatively correlated with intimal and necrotic focus thickness, positively correlated with fibrous cap thickness (P < 0.01), and negatively correlated with inflammatory factors, VCAM1 and MMP-9 (P < 0.01). CONCLUSIONS: The expression of ATF3 may be related to the progression and stability of atherosclerotic plaques, and may affect the structural stability of atherosclerotic plaques by regulating the inflammatory response, thus participating in the regulation of atherosclerotic progression.

Age-Related Changes of Material Mechanics and Bone Material Parameters of Rat Skulls.

ABSTRACT: Objective To study the relationship between material mechanics and bone material parameters of rat skulls and their correlation with age by examination of the parameters. Methods Forty-eight healthy male SD rats were divided into 2, 4, 6, 8, 17, 26, 52 and 104 week groups according to their age. Each group had six rats. The right cranium was compressed by KD Ⅱ-0.2 microcomputer controlled electronic universal testing machine, and material mechanics parameters （ultimate load, compression strength and compression modulus） were measured, then the skull slices were cut off and scanned by Micro-CT system to detect bone material parameters （skull thickness, bone mineral density, bone volume, and trabecular thickness）. Results The differences in ultimate load, compression strength and compression modulus among all groups had statistical significance （P<0.05）, and were positively correlated with age within 26 weeks （P<0.05）. The differences in skull thickness, bone mineral density, bone volume and trabecular thickness among all groups had statistical significance （P<0.05）, and were positively correlated with age within 52 weeks （P<0.05）. All material mechanics parameters were positively correlated with bone material parameters （P<0.05）. Conclusion There is a positive correlation between bone material parameters （skull thickness, bone mineral density, bone volume, trabecular thickness）, material mechanics parameter （skull ultimate load, compression strength, compression modulus） and age in a certain range, which can be used to infer age.

Inhibitory effects of long-chain fatty acids on VFA degradation and beta-oxidation.

The inhibitory effects of major long-chain fatty acids (LCFA), which have 16 or 18 carbons, not only on acetate degradation, but also on propionate degradation and beta-oxidation were examined in anaerobic serum bottle tests at 35 degrees C with the acclimated granular sludges. A modified Gompertz equation described cumulative methane production to assess the rates of VFA degradation and beta-oxidation, which were applied to a simplified noncompetitive model and a simplified substrate inhibition model, respectively. The specific methane production rates on acetate decreased as LCFA concentration increased, which was in good agreement with the noncompetitive inhibition model. Unsaturated oleate (C18:1) and linoleate (C18:2) were more inhibitory than saturated stearate (C18:0) and palmitate (C16:0) on acetate degradation. LCFA inhibition on propionate degradation was similar to that for acetate; however, propionate degradation was less inhibited than acetate degradation. Beta-oxidation was the rate-limiting step in LCFA degradation in most cases. As LCFA concentration increased, beta-oxidation rate reached the maximum value, and then decreased, which confirmed the substrate inhibition of LCFA. Oleate, the most abundant LCFA in wastewater, could be degraded more quickly than saturated LCFA containing the same or even less carbon in spite of relatively high toxicity on acetate degradation.