| Summary: | 碩士 === 國立陽明大學 === 生物藥學研究所 === 103 === The CDGSH iron sulfur domain2 (CISD2) is an evolutionarily conserved gene, which is related to longevity and mitochondria function in mammals. Also, it’s the causative gene for Wolfram syndrome 2 (WFS2).
WFS2 is a rare autosomal recessive neurodegenerative disorder characterized by diabetes mellitus, hearing loss, optic atrophy or neuropathy. Additionally, some of the WFS2 patients were accompanied with anemia.
In our study, we observed some abnormal conditions in erythrocyte maturation in Cisd2 knockout (KO) mice, which was an established animal model of WFS2. Though, there were subtle differences of total erythrocyte counts between WT and Cisd2 KO mice 〔WT = 11.20 ± 0.41 (1012/L) ; Cisd2 KO = 11.57 ± 0.69 (1012/L)，p = 0.043〕. Cisd2 KO mice showed ectopic accumulation of reticulocytes (WT = 1.67 ± 0.62 % ; Cisd2 KO = 3.15 ± 1.20 %，p = 0.0001). Although the possibility of anemia was excluded, these results showed reticulocytosis in Cisd2 KO mice. In addition, we found excessive numbers of remnant mitochondria in reticulocytes of Dendra2; Cisd2 KO mice (WT = 2.99 ± 0.16 % ; Cisd2 KO = 6.30 ± 1.12 %，p = 0.001) . Moreover, we used GFP-LC3; Cisd2 KO mice as a model to investigate the relations between Cisd2 protein and autophagy. Interestingly, a dramatic decreased of autophagosome in reticulocytes e was observed in Cisd2 KO mice (WT = 8.37 ± 3.18 % ; Cisd2 KO = 3.44 ± 1.18 %，p = 0.002) .
These results pointed out the potential function roles of Cisd2 protein in autophagosome formation and mitochondria elimination of reticulocytes.
To further examine the cause of unusual maturation of erythrocytes in Cisd2 KO mice, the expression of mitophagy-related genes in reticulocytes and the distribution of population of erythroid progenitors in bone marrow of Cisd2 KO mice were analyzed by reverse transcriptase PCR (RT-PCR) and flow cytometry analysis respectively.
Finally, we found the deficiency of Cisd2 affected both the expression of mitophagy-related genes and the differentiation of hematopoietic stem cell. According to these results, we suggested that Cisd2 protein might plays a crucial role in both mitophagy and the differentiation of erythroid progenitors.
|
|---|
