Studies On Expressions Of Caspase-3, Caspase-8 And Caspase-9 And Apoptosis Of Hematopoietic Cells In Chronic Mountain Sickness

Objective Chronic mountain sickness (CMS) is a common disease in the plateau region, and its pathogenesis is very complex. Lots of studies confirmed that excessive proliferation of red blood cells played an important role in its pathophysiology. However, the study on the apoptosis of hematopoietic cells is limited. In fact, apoptosis changes of bone marrow hematopoietic cells is closely related with the occurrence and development of CMS. Lots researches proved that cysteinyl aspartate specific proteinase (caspase) plays an important role in cell apoptosis, and it is a key factor in determining the apoptosis change and the ways of apoptosis. The aims of this study is to observe the expressions of caspase-3, caspase-8 and caspase-9 in hematopoietic cells and the changes of apoptosis in patients with CMS, exploring the effect of apoptosis and caspase in CMS.Method The CMS was diagnosed according to"Qinghai diagnostic criteria for chronic mountain sickness". The bone marrow specimens were collected from 18 patients with CMS (CMS group) and 16 patients with fracture of orthopedics (Control group). They were all males. The average ages were (45.8±11.4) years old in CMS group and (44.6±11.1) years old in Control group. The bone marrow mononuclear cells (BMMNCs) were separated from the bone marrow specimens using lymphocytes separation medium. The apoptosis index (AI) of BMMNCs was measured by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) technique, and the caspase-3, caspase-8 and caspase-9 mRNA were measured by RT-PCR technique. These parameters mentioned above were compared between CMS group and Control group, and the correlations among caspase-3, caspase-8, caspase-9, hemoglobin (Hb) concentration and AI were analyzed. Results①The AI of BMMNCs in patients with CMS (8.51%±3.35%) was lower than that in controls (16.00%±4.28%), P<0.001.②The caspase-3, caspase-8 and caspase-9 mRNA expressions were (0.19±0.05), (0.28±0.07) and (0.23±0.08), respectively, in CMS patients, and were (0.47±0.10) and (0.45±0.09) and (0.41±0.09), respectively, in the controls. The expressions of caspase-3, caspase-8 and caspase-9 mRNA in CMS patients were lower than those in controls, respectively, P<0.001.③Hb was negatively correlated with caspase-3, caspase-8 and caspase-9 in CMS patients, r values were -0.96, -0.52 and -0.61, respectively, P<0.05. There was a negative relationship between AI and Hb (r=-0.89, P<0.01), and a positive relationship between AI and caspase-3 (r=-0.81, P<0.01) in CMS patients. However, the significant relationship was not found between the AI and caspase-8 or caspase-9 mRNA (P>0.05).④caspase-3 was positively correlated with caspase-8 and caspase-9 (r values were -0.53 and -0.72, respectively, P<0.01) in CMS patients.Conclusion The results of this study showed that the AI decreased in CMS, indicating the apoptosis of BMMNCs was downregulated. And the low expressions of caspase-3, caspase-8 and caspase-9 might be involved in the mechanism of the change of hematopoietic cells apoptosis.