Familial longevity study reveals a significant association of mitochondrial DNA copy number between centenarians and their offspring.

Reduced mitochondrial function is an important cause of aging and age-related diseases. We previously revealed a relatively higher level of mitochondrial DNA (mtDNA) content in centenarians. However, it is still unknown whether such an mtDNA content pattern of centenarians could be passed on to their offspring and how it was regulated. To address these issues, we recruited 60 longevity families consisting of 206 family members (cohort 1) and explored their mtDNA copy number. The results showed that the first generation of the offspring (F1 offspring) had a higher level of mtDNA copy number than their spouses (p < 0.05) independent of a gender effect. In addition, we found a positive association of mtDNA copy number in centenarians with that in F1 offspring (r = 0.54, p = 0.0008) but not with that in F1 spouses. These results were replicated in another independent cohort consisting of 153 subjects (cohort 2). RNA sequencing analysis suggests that the single-stranded DNA-binding protein 4 was significantly associated with mtDNA copy number and was highly expressed in centenarians as well as F1 offspring versus the F1 spouses, thus likely regulates the mtDNA copy number in the long-lived family members. In conclusion, our results suggest that the pattern of high mtDNA copy number is likely inheritable, which may act as a favorable factor to familial longevity through assuring adequate energy supply.

Mitochondrial DNA plays an equal role in influencing female and male longevity in centenarians.

The mitochondrion is a double membrane-bound organelle which plays important functional roles in aging and many other complex phenotypes. Transmission of the mitochondrial genome in the matrilineal line causes the evolutionary selection sieve only in females. Theoretically, beneficial or neutral variations are more likely to accumulate and be retained in the female mitochondrial genome during evolution, which may be an initial trigger of gender dimorphism in aging. The asymmetry of evolutionary processes between gender could lead to males and females aging in different ways. If so, gender specific variation loads could be an evolutionary result of maternal heritage of mitochondrial genomes, especially in centenarians who live to an extreme age and are considered as good models for healthy aging. Here, we tested whether the mitochondrial variation loads were associated with altered aging patterns by investigating the mtDNA haplogroup distribution and genetic diversity between female and male centenarians. We found no evidence of differences in aging patterns between genders in centenarians. Our results indicate that the evolutionary consequence of gender dimorphism in mitochondrial genomes is not a factor in the altered aging patterns in human, and that mitochondrial DNA contributes equally to longevity in males and females.

Improved lipids, diastolic pressure and kidney function are potential contributors to familial longevity: a study on 60 Chinese centenarian families.

Centenarians are a good healthy aging model. Interestingly, centenarians' offspring are prone to achieve longevity. Here we recruited 60 longevity families and investigated the blood biochemical indexes of family members to seek candidate factors associated with familial longevity. First, associations of blood indexes with age were tested. Second, associations of blood parameters in centenarians (CEN) with their first generation of offspring (F1) and F1 spouses (F1SP) were analyzed. Third, genes involved in regulating target factors were investigated. We found that total cholesterol (TC) and triglyceride (TG) increased with age (20-80 years), but decreased in CEN. Similarly, blood urea nitrogen (BUN) and blood creatinine (BCr) increased with age (20-80 years), but were maintained on a plateau in CEN. Importantly, we first revealed dual changes in blood pressure, i.e., decreased diastolic blood pressure but increased systolic blood pressure in CEN, which associated with altered CST3 expression. Genetic analysis revealed a significant association of blood uric acid (BUA) and BCr in CEN with F1 but not with F1SP, suggesting they may be heritable traits. Taken together, our results suggest serum lipids, kidney function and especially diastolic pressure rather than systolic pressure were improved in CEN or their offspring, suggesting these factors may play an important role in familial longevity.

Role of AIF-1 in the regulation of inflammatory activation and diverse disease processes.

Allograft Inflammatory Factor-1 (AIF-1) is a 17kDa cytoplasmic, calcium-binding, inflammation-responsive scaffold protein that is mainly expressed in immunocytes. AIF-1 influences the immune system at several key points and thus modulates inflammatory diseases. AIF-1 boosts the expression of inflammatory mediators such as cytokines, chemokines, inducible nitric oxide synthase (iNOS) and promotes inflammatory cell proliferation and migration. Here we provide an overview of the different pathological processes regulated by AIF-1 mainly including allograft rejection, autoimmune diseases, central nervous system (CNS) injury, vasculopathy and cancer et al.

Daintain/AIF-1 (allograft inflammatory factor-1) promotes erythrocyte lysis and heme release probably via binding to hemoglobin.

Free heme is potentially cytotoxic, particularly in the presence of oxidants or activated phagocytes. Daintain/AIF-1 (allograft inflammatory factor-1) is a macrophage factor that has been implicated in the regulation of inflammation. In the present study, daintain/AIF-1 was found to induce cytolysis of erythrocytes, resulting in heme release in vitro. Furthermore, the interacting protein of daintain/AIF-1 was purified by daintain/AIF-1-6 histidine antigen fusion protein nickel affinity chromatography. MALDI-TOF-MS analysis identified hemoglobin subunit beta-1 as an interacting protein of daintain/AIF-1.These data suggest that daintain/AIF-1 may be involved in heme-associated diseases.

17ß-Estradiol increased the expression of daintain/AIF-1 in RAW264.7 macrophages.

We investigated the effect of 17ß-estradiol (E2) on the expression of daintain/AIF-1, a marker of activated macrophages, in RAW264.7. E2 upregulated the protein and mRNA levels of daintain/AIF-1 in similar manners under physiological concentrations of 10(-11) M to 10(-7) M. The application of ICI 182,780, an estrogen receptor (ER) antagonist, attenuated E2-induced daintain/AIF-1 production, suggesting the involvement of ER in this process.