RESUMO
BACKGROUND: Although recent studies have indicated that both orthostatic hypotension and orthostatic hypertension independently predict cardiovascular events, the underlying mechanisms are still controversial. The aim of the study was to investigate the relationships between orthostatic changes and organ damage in subjects over 60 years old. METHODS: This is a prospective observational cohort study. One thousand nine hundred and ninety-seven subjects over 60 years old were enrolled. Participants were grouped according to whether they had a drop ≥ 20 mmHg in systolic or ≥ 10 mmHg in diastolic BP (orthostatic hypotension), an increase in mean orthostatic systolic blood pressure ≥ 20 mm Hg (orthostatic hypertension), or normal changes within 3 min of orthostatism. Multiple regression modeling was used to investigate the relationship between orthostatic hypotension, orthostatic hypertension and subclinical organ damage with adjustment for confounders. RESULTS: Orthostatic hypotension and orthostatic hypertension were found in 461 (23.1%) and 189 (9.5%) participants, respectively. Measurement of carotid intima-media thickness (IMT), brachial-ankle pulse wave velocity (baPWV), clearance of creatinine, and microalbuminuria were associated with orthostatic hypotension; measurement of IMT and baPWV were associated with orthostatic hypertension in a cruse model. After adjustment, IMT [odds ratio (OR), 95% confidence interval (CI) per one-SD increment: 1.385, 1.052-1.823; P = 0.02], baPWV (OR = 1.627, 95% CI: 1.041-2.544; P = 0.033) and microalbuminuria (OR = 1.401, 95% CI: 1.002-1.958; P = 0.049) were still associated with orthostatic hypotension, while orthostatic hypertension was only associated with IMT (OR = 1.730, 95% CI: 1.143-2.618; P = 0.009). CONCLUSIONS: Orthostatic hypotension seems to be independently correlated with increased carotid atherosclerosis, arterial stiffness and renal damage in subjects over 60 years old. Orthostatic hypertension correlates with carotid atherosclerosis only.
RESUMO
Osteosarcoma is the most common malignant bone tumor in children and adolescents. Aberrant expression of HOXA5 results in various diseases, including cancers. However, the specific function and molecular mechanism of HOXA5 in osteosarcoma is not fully understood. In the present study, we focused on HOXA5 in U2OS and MG63 cells in vitro. We observed lower expression of HOXA5 in U2OS, MG63, and SaOS2 human osteosarcoma cells, compared with hFOB1.19 human osteoblastic cells. HOXA5 overexpression in U2OS and MG63 cells markedly reduced cell survival and proliferation and elevated cell apoptosis and caspase-3 activity. HOXA5 also activated the p38α MAPK pathway by increasing p53. Treating U2OS and MG63 cells with the p53 inhibitor α-pifithrin or the p38α MAPK inhibitor SB203580 led to higher cell survival and proliferation and lower cell apoptosis, compared with the pcDNA3.1-HOXA5 group. In conclusion, our study showed that the p53 and p38α MAPK signal axis facilitated HOXA5's role in inhibiting growth and stimulating apoptosis of osteosarcoma cells.
