[Study on apoptosis, cytochrome C and mitochondrial membrane potential in CD71(+) nucleated erythrocytes in patients with chronic mountain sickness].

Objective: To investigate the changes of CD71(+) nucleated erythrocyte apoptosis, cytochrome C (Cyt-C) and mitochondrial membrane potential (MMP) in bone marrow of chronic mountain sickness (CMS). Methods: 14 patients with CMS and 15 patients with simple old fracture were divided into CMS group and control group, respectively.Bone marrow mononuclear cells (BMMNC) were separated, marked with CD71 monoclonal antibody and stained with Annexin V-FITC/PI.Then the apoptotic index of CD71(+) nucleated erythrocytes was determined by flow cytometry.CD71(+) nucleated erythrocytes were sorted out by magnetic column separation, and Cyt-C mRNA was detected by RT-qPCR, MMP was detected by JC-1 staining flow cytometry. Results: The apoptotic index of CD71(+) nucleated erythrocytes was (1.9±1.4)% in the CMS group, and was (3.2±1.5)% in the control group, with significant difference between the two groups ( P <0.05). The expression of Cyt-C mRNA was (0.72±0.14) in the CMS group, and was (1.00±0.15) in the control group, with significant difference between the two groups ( P <0.01). The MMP was (5.0±2.2) in the CMS group, and was (3.3±0.9) in the control group, with significant difference between the two groups ( P <0.05). The apoptotic index of CD71(+) nucleated erythrocytes was negatively correlated with hemoglobin in CMS group ( r =-0.569, P =0.034). But there was no significant correlation among apoptosis index, MMP and Cyt-C mRNA. Conclusions: The apoptosis index of CD71(+) nucleated erythrocytes decreased in CMS patients, which was negatively correlated with the level of hemoglobin, indicating that the decline of apoptosis index of CD71(+) nucleated erythrocytes may be related to the accumulation of red blood cells in CMS.The MMP increased and Cyt-C mRNA expression decreased in CD71(+) nucleated erythrocytes of CMS patients, which suggests that the change of mitochondrial pathway of apoptosis might be involved in the down-regulation of CD71(+) nucleated erythrocytes apoptosis in CMS patients.But there was no significant correlation among CD71(+) nucleated erythrocyte apoptosis index, MMP and Cyt-C mRNA levels, which indicates that the mechanism of CD71(+) nucleated erythrocytes apoptosis is complex in CMS.