Abstract：
BACKGROUND: Both we and others have found that RBC counts are significantly lower in older compared to younger. However, when gender is factored in, a significant age-related decrease of RBC counts is observed only in men but not in women.
METHODS: qPCR and confocal microscopy were used to detect the presence of mtDNA in RBCs. Flow cytometry and specific inhibitors were used to determine how RBCs uptake cf-mtDNA. The peripheral blood was collected from 202 young adults and 207 older adults and RBC and plasma were isolated. The levels of TLR9+RBCs and apoptotic RBCs after uptake of cf-mtDNA by RBCs were measured by flow cytometry. The kit detects changes in SOD and MDA levels after cf-mtDNA uptake by RBCs. Young RBCs (YR) and old RBCs (OR) from single individuals were separated by Percoll centrifugation.
RESULTS: We found a significant decrease in RBC counts and a significant increase in the RDW with aging only in men. We also found that significantly elevated mtDNA content in RBCs was observed only in men during aging and was not found in women. Further studies demonstrated that RBCs could take up cf-mtDNA via TLR9, and the uptake of mtDNA might lead to a decrease in the RBC number and an increase in RDW due to an increase of oxidative stress.
CONCLUSIONS: The RBC mtDNA content might be a potential marker of RBC aging and the elevated RBC mtDNA content might be the cause of faster senescence in males than females.
METHODS: qPCR and confocal microscopy were used to detect the presence of mtDNA in RBCs. Flow cytometry and specific inhibitors were used to determine how RBCs uptake cf-mtDNA. The peripheral blood was collected from 202 young adults and 207 older adults and RBC and plasma were isolated. The levels of TLR9+RBCs and apoptotic RBCs after uptake of cf-mtDNA by RBCs were measured by flow cytometry. The kit detects changes in SOD and MDA levels after cf-mtDNA uptake by RBCs. Young RBCs (YR) and old RBCs (OR) from single individuals were separated by Percoll centrifugation.
RESULTS: We found a significant decrease in RBC counts and a significant increase in the RDW with aging only in men. We also found that significantly elevated mtDNA content in RBCs was observed only in men during aging and was not found in women. Further studies demonstrated that RBCs could take up cf-mtDNA via TLR9, and the uptake of mtDNA might lead to a decrease in the RBC number and an increase in RDW due to an increase of oxidative stress.
CONCLUSIONS: The RBC mtDNA content might be a potential marker of RBC aging and the elevated RBC mtDNA content might be the cause of faster senescence in males than females.
摘要：
背景：我们和其他人都发现，与年轻人相比，老年人的RBC计数显着降低。然而,当性别被考虑在内时，仅在男性中观察到与年龄相关的RBC计数显著下降,而在女性中未观察到.
方法：使用qPCR和共聚焦显微镜检测红细胞中mtDNA的存在。流式细胞术和特异性抑制剂用于确定红细胞如何摄取cf-mtDNA。收集202名年轻人和207名老年人的外周血，并分离出红细胞和血浆。通过流式细胞术测量RBC摄取cf-mtDNA后TLR9+RBC和凋亡RBC的水平。该试剂盒检测红细胞摄取cf-mtDNA后SOD和MDA水平的变化。通过Percoll离心分离来自单个个体的年轻RBC(YR)和老RBC(OR)。
结果：我们发现仅在男性中，随着年龄的增长，RBC计数显着减少，RDW显着增加。我们还发现，红细胞中mtDNA含量显着升高仅在男性衰老期间观察到，而在女性中未发现。进一步的研究表明，红细胞可以通过TLR9吸收cf-mtDNA，mtDNA的吸收可能导致RBC数量减少和由于氧化应激增加而导致的RDW增加。
结论：红细胞mtDNA含量可能是红细胞衰老的潜在标志，红细胞mtDNA含量升高可能是男性衰老快于女性的原因。
方法：使用qPCR和共聚焦显微镜检测红细胞中mtDNA的存在。流式细胞术和特异性抑制剂用于确定红细胞如何摄取cf-mtDNA。收集202名年轻人和207名老年人的外周血，并分离出红细胞和血浆。通过流式细胞术测量RBC摄取cf-mtDNA后TLR9+RBC和凋亡RBC的水平。该试剂盒检测红细胞摄取cf-mtDNA后SOD和MDA水平的变化。通过Percoll离心分离来自单个个体的年轻RBC(YR)和老RBC(OR)。
结果：我们发现仅在男性中，随着年龄的增长，RBC计数显着减少，RDW显着增加。我们还发现，红细胞中mtDNA含量显着升高仅在男性衰老期间观察到，而在女性中未发现。进一步的研究表明，红细胞可以通过TLR9吸收cf-mtDNA，mtDNA的吸收可能导致RBC数量减少和由于氧化应激增加而导致的RDW增加。
结论：红细胞mtDNA含量可能是红细胞衰老的潜在标志，红细胞mtDNA含量升高可能是男性衰老快于女性的原因。
