The tight coordination between mitochondrial biogenesis and mitophagy can be dysregulated during aging, critically influencing whole-body metabolism, health, and lifespan. To date, caloric ...restriction (CR) appears to be the most effective intervention strategy to improve mitochondrial turnover in aging organisms. The development of pharmacological mimetics of CR has gained attention as an attractive and potentially feasible approach to mimic the CR phenotype. Polyphenols, ubiquitously present in fruits and vegetables, have emerged as well-tolerated CR mimetics that target mitochondrial turnover. Here, we discuss the molecular mechanisms that orchestrate mitochondrial biogenesis and mitophagy, and we summarize the current knowledge of how CR promotes mitochondrial maintenance and to what extent different polyphenols may mimic CR and coordinate mitochondrial biogenesis and clearance.
The maintenance of functional mitochondria is critical during development as well as throughout life. The slowdown of mitochondrial turnover associated with aging has been shown to contribute to the pathogenesis of age-related diseases.Caloric restriction is a well-known intervention that has been shown to ameliorate mitochondrial biogenesis and mitophagy, thereby attenuating age-related decline in mitochondrial function. However, the strict and life-long compliance with this dietary regimen has promoted the investigation of compounds with caloric restriction mimetic properties.Plant polyphenols may represent an attractive source of caloric restriction mimetics. Recent research has confirmed that these compounds may partly mimic the beneficial effects of caloric restriction, inducing molecular mechanisms that govern mitochondrial biogenesis and mitophagy.
Evidence from observational studies indicates that endometriosis and depression often co-occur. However, conflicting evidence exists, and the etiology as well as biological mechanisms underlying ...their comorbidity remain unknown. Utilizing genome-wide association study (GWAS) data, we comprehensively assessed the relationship between endometriosis and depression. Single nucleotide polymorphism effect concordance analysis (SECA) found a significant genetic overlap between endometriosis and depression (
P
Fsig
-
permuted
= 9.99 × 10
−4
). Linkage disequilibrium score regression (LDSC) analysis estimated a positive and highly significant genetic correlation between the two traits (
r
G
= 0.27,
P
= 8.85 × 10
−27
). A meta-analysis of endometriosis and depression GWAS (sample size = 709,111), identified 20 independent genome-wide significant loci (
P
< 5 × 10
−8
), of which eight are novel. Mendelian randomization analysis (MR) suggests a causal effect of depression on endometriosis. Combining gene-based association results across endometriosis and depression GWAS, we identified 22 genes with a genome-wide significant Fisher’s combined
P
value (
FCP
gene
< 2.75 × 10
−6
). Genes with a nominal gene-based association (
P
gene
< 0.05) were significantly enriched across endometriosis and depression (
P
binomial
-
test
= 2.90 × 10
−4
). Also, genes overlapping the two traits at
P
gene
< 0.1 (
P
binomial
-
test
= 1.31 × 10
−5
) were significantly enriched for the biological pathways ‘cell–cell adhesion’, ‘inositol phosphate metabolism’, ‘Hippo-Merlin signaling dysregulation’ and ‘gastric mucosa abnormality’. These results reveal a shared genetic etiology for endometriosis and depression. Indeed, additional analyses found evidence of a causal association between each of endometriosis and depression and at least one abnormal condition of gastric mucosa. Our study confirms the comorbidity of endometriosis and depression, implicates links with gastric mucosa abnormalities in their causal pathways and reveals potential therapeutic targets for further investigation.
Mitochondrial dysfunction is an important component of the aging process and has been implicated in the development of many human diseases. Mitochondrial DNA copy number (mtDNAcn), an indirect ...biomarker of mitochondrial function, is sensitive to oxidative damage. Few population-based studies have investigated the impact of fruit and vegetable consumption and cigarette smoke (2 major sources of exogenous antioxidants and oxidants) on leukocyte mtDNAcn.
We investigated the association between fruit and vegetable consumption, cigarette smoke, and leukocyte mtDNAcn based on data from the Nurses’ Health Study (NHS).
Data from 2769 disease-free women in the NHS were used to examine the cross-sectional associations between dietary sources of antioxidants, cigarette smoke, and leukocyte mtDNAcn. In vitro cell-based experiments were conducted to support the findings from the population-based study.
In the multivariable-adjusted model, both whole-fruit consumption and intake of flavanones (a group of antioxidants abundant in fruit) were positively associated with leukocyte mtDNAcn (P-trend = 0.005 and 0.02, respectively), whereas pack-years of smoking and smoking duration were inversely associated with leukocyte mtDNAcn (P-trend = 0.01 and 0.007, respectively). These findings are supported by in vitro cell-based experiments showing that the administration of naringin, a major flavanone in fruit, led to a substantial increase in mtDNAcn in human leukocytes, whereas exposure to nicotine-derived nitrosamine ketone, a key carcinogenic ingredient of cigarette smoke, resulted in a significant decrease in mtDNAcn of cells (all P < 0.05). Further in vitro studies showed that alterations in leukocyte mtDNAcn were functionally linked to the modulation of mitochondrial biogenesis and function.
Fruit consumption and intake of dietary flavanones were associated with increased leukocyte mtDNAcn, whereas cigarette smoking was associated with decreased leukocyte mtDNAcn, which is a promising biomarker for oxidative stress–related health outcomes.
Leukocyte telomere length (LTL), which reflects telomere length in other somatic tissues, is a complex genetic trait. Eleven SNPs have been shown in genome-wide association studies to be associated ...with LTL at a genome-wide level of significance within cohorts of European ancestry. It has been observed that LTL is longer in African Americans than in Europeans. The underlying reason for this difference is unknown. Here we show that LTL is significantly longer in sub-Saharan Africans than in both Europeans and African Americans. Based on the 11 LTL-associated alleles and genetic data in phase 3 of the 1000 Genomes Project, we show that the shifts in allele frequency within Europe and between Europe and Africa do not fit the pattern expected by neutral genetic drift. Our findings suggest that differences in LTL within Europeans and between Europeans and Africans is influenced by polygenic adaptation and that differences in LTL between Europeans and Africans might explain, in part, ethnic differences in risks for human diseases that have been linked to LTL.
Omega-3 (n–3) and omega-6 (n–6) fatty acids may contribute to oxidative stress and inflammation, which are related to telomere shortening. Evidence supporting an association between intake of n–3 or ...n–6 fatty acids and leukocyte telomere length (LTL) in males has been limited.
We conducted a cross-sectional study to examine the associations of total or individual n–3 or total n–6 fatty acid intake with LTL in US males.
We included 2,494 US males with LTL measurement from 4 nested case–control studies within the Health Professionals Follow-Up Study. Individuals with previous histories of cancers, diabetes, and cardiovascular diseases at or before blood collection were excluded. Blood collection was performed between 1993 and 1995, and relevant information including n–3 and n–6 intake was collected in 1994 by questionnaire. The LTL was log-transformed and Z scores of the LTL were calculated for statistical analyses by standardizing the LTL in comparison with the mean within each selected nested case–control study.
We found that consumption of DHA (22:6n–3) was positively associated with LTL. In the multivariable-adjusted model, compared with individuals who had the lowest intake of DHA (i.e., first quartile group), the percentage differences (95% CIs) of LTL were −3.7 (−13.7, 7.5), 7.0 (−4.3, 19.7), and 8.2 (−3.5, 21.3) for individuals in the second, third, and fourth quartiles of consumption, respectively (P-trend = 0.0498). We did not find significant associations between total n–3 or total n–6 fatty acid intakes and LTL. In addition, we found that males who consumed canned tuna had longer LTL than those who did not; in the multivariable-adjusted model, the percentage difference of LTL was 10.5 (95% CI: 1.3, 20.4) (P = 0.02).
Our results suggest that higher intakes of DHA and canned tuna consumption are associated with longer LTL.
Poor lifestyles have been linked to insulin insensitivity/hyperinsulinemia, which may contribute to downstream changes such as inflammation and oxidative damage and the development of chronic ...diseases. As a biomarker of intracellular oxidative stress, leukocyte mitochondrial DNA copy number (mtDNA-CN) has been related to lifestyle factors including diet and weight. No epidemiologic study has examined the relation between combined insulinemic potential of lifestyle and mtDNA-CN.
Our aim was to examine the association between Empirical Lifestyle Index for Hyperinsulinemia (ELIH) and leukocyte mtDNA-CN in US men and women.
This cross-sectional analysis included 2835 white adults without cancers, diabetes, or cardiovascular disease at blood collection, including 2160 women from the Nurses' Health Study and 675 men from the Health Professionals Follow-Up Study. ELIH is an index based on plasma C-peptide that characterizes the insulinemic potential of lifestyle (diet, body weight, and physical activity). Relative mtDNA-CN in peripheral blood leukocytes was measured by qPCR-based assay.
We found a significant inverse association between ELIH and mtDNA-CN. In multivariable-adjusted linear models, absolute least squares means ± SDs of mtDNA-CN z score across ELIH quintiles in women were as follows: Q1: 0.14 ± 0.05; Q2: 0.04 ± 0.06; Q3: 0.008 ± 0.05; Q4: 0.01 ± 0.05; and Q5: −0.06 ± 0.05 (P-trend = 0.006). Means ± SDs in men were as follows: Q1: 0.25 ± 0.09; Q2: 0.23 ± 0.09; Q3: 0.07 ± 0.09; Q4: 0.02 ± 0.09; and Q5: −0.04 ± 0.09 (P-trend = 0.007). Means ± SDs in all participants were as follows: Q1: 0.16 ± 0.05; Q2: 0.07 ± 0.05; Q3: 0.01 ± 0.05; Q4: 0.01 ± 0.05; and Q5: −0.05 ± 0.05 (P-trend = 0.0004).
Hyperinsulinemic lifestyles (i.e., higher ELIH) were associated with lower leukocyte mtDNA-CN among subjects without major diseases, suggesting that the difference in lifestyle insulinemic potential may be related to excessive oxidative stress damage.
Accelerated telomere shortening has been associated with several age-related diseases and/or decreased lifespan in humans. The Mediterranean diet (MedDiet) is considered to be 1 of the most ...recognized diets for disease prevention and healthy aging, partially due to its demonstrated anti-inflammatory and antioxidative properties which may impact on telomere length (TL). The aim of this meta-analysis was to determine the associations between MedDiet adherence and TL maintenance. MEDLINE-PubMed and Cochrane databases were searched up to December 2018 for studies evaluating the association between MedDiet adherence and TL in blood cells. Two reviewers, working independently, screened all titles and abstracts to identify studies that met the inclusion criteria cross-sectional, case-control, and prospective cohort studies and randomized clinical trials (RCTs) published in English and excluded nonoriginal articles. Data were pooled by the generic inverse variance method using the random effects model and expressed as standardized mean difference (SMD). Heterogeneity was identified using the Cochran Q test and quantified by the I2 statistic. A total of 8 original cross-sectional studies were included for the quantitative meta-analysis, comprising a total of 13,733 participants from 5 countries. A positive association between adherence to the MedDiet and TL was observed in all meta-analyses, with the exception of those conducted only in men: SMD (95% CI) of 0.130 (0.029; 0.231) for all subjects, 0.078 (0.005; 0.152) for women, and 0.095 (–0.005; 0.195) for men. Only 1 prospective cohort study and 1 RCT were identified, therefore, we could not undertake a meta-analysis for these study designs. The present meta-analysis of cross-sectional studies demonstrates that higher MedDiet adherence is associated with longer TL. At the same time, larger and high-quality prospective studies and clinical trials are warranted to confirm this association.
Abstract
Background
Adherence to healthy lifestyles/behaviours promotes healthy ageing. However, little is known about whether age, sex and/or race/ethnicity moderate associations of ...lifestyle/behavioural factors with relative telomere length (RTL), a potential biomarker of ageing.
Methods
We included 749 midlife to older non-Hispanic White (n = 254), Black (n = 248) and Hispanic (n = 247) US participants mean (standard deviation) age = 69.3 (7.2) years; women: 50.5%. We extracted genomic DNA from peripheral leucocytes. RTL was assayed using real-time quantitative polymerase chain reaction. Multivariable regression was used to examine associations between lifestyle/behavioural exposures (i.e. physical activity, alcohol consumption, smoking and depression) with RTL.
Results
Increasing chronological age was associated with shorter RTL (P < 0.01). Higher physical activity was associated with longer RTL (P-trend = 0.03); daily versus never/rare alcohol consumption and 30+ versus <5 smoking pack-year were associated with shorter RTLs (P-trend = 0.02). Associations varied significantly by sex and race/ethnicity. The association between physical activity and longer RTL appeared strongest among non-Hispanic Whites (P-interaction = 0.01). Compared to men, women had stronger associations between heavy smoking and shorter RTLs (P-interaction = 0.03). Light/moderate alcohol consumption (monthly/weekly) was associated with longer RTL among non-Hispanic Whites, while daily consumption was related to shorter RTLs among Blacks and Hispanics (P-interactions < 0.01). Associations of daily alcohol and heavy smoking with shorter RTLs were particularly apparent among Black women.
Conclusion
We observed novel variations by sex and race/ethnicity in associations between lifestyle/behavioural factors and RTL. Further work is needed to replicate these findings and to address potential public health implications for modifying strategies by sex or across racial/ethnic groups to optimise lifestyles/behaviours for healthy ageing.
Posttraumatic stress disorder (PTSD) is a common and debilitating mental disorder with a particularly high burden for women. Emerging evidence suggests PTSD may be more heritable among women and ...evidence from animal models and human correlational studies suggest connections between sex-linked biology and PTSD vulnerability, which may extend to the disorder's genetic architecture. We conducted a genome-wide association study (GWAS) of PTSD in a primarily African American sample of women from the Detroit Neighborhood Health Study (DNHS) and tested for replication in an independent cohort of primarily European American women from the Nurses Health Study II (NHSII).
We genotyped 413 DNHS women – 94 PTSD cases and 319 controls exposed to at least one traumatic event – on the Illumina HumanOmniExpress BeadChip for >700,000 markers and tested 578 PTSD cases and 1963 controls from NHSII for replication. We performed a network-based analysis integrating data from GWAS-derived independent regions of association and the Reactome database of functional interactions.
We found genome-wide significant association for one marker mapping to a novel RNA gene, lincRNA AC068718.1, for which we found suggestive evidence of replication in NHSII. Our network-based analysis indicates that our top GWAS results were enriched for pathways related to telomere maintenance and immune function. Our findings implicate a novel RNA gene, lincRNA AC068718.1, as risk factor for PTSD in women and add to emerging evidence that non-coding RNA genes may play a crucial role in shaping the landscape of gene regulation with putative pathological effects that lead to phenotypic differences.
Purpose
Endometriosis is associated with ovarian cancer, but the relation with endometrial cancer is unclear. Prior studies generally were retrospective and had potential limitations, including use ...of self-reported endometriosis, failure to account for delays between symptom onset and endometriosis diagnosis, and changes in risk factors post-endometriosis diagnosis. We evaluated whether these limitations obscured a weak association with endometrial cancer and the extent to which these limitations impacted associations with ovarian cancer.
Methods
Cox proportional hazards regression models were used to assess associations between endometriosis and cancer risk, evaluating the impacts of self-reported vs. laparoscopically confirmed endometriosis, delayed diagnosis, and post-endometriosis diagnosis changes in risk factor exposures on relative risk estimates.
Results
Over 18 years of follow-up, we identified 228 ovarian and 166 endometrial cancers among 102,025 and 97,109 eligible women, respectively. Self-reported endometriosis was associated with ovarian cancer relative risk (RR): 1.81; 95% confidence interval (CI): 1.26–2.58; this association was stronger for laparoscopically confirmed endometriosis (HR: 2.14; 95% CI 1.45–3.15). No association was observed with endometrial cancer (self-report RR: 0.78; 95% CI 0.42–1.44; laparoscopic-confirmation RR: 0.76; 95% CI 0.35–1.64). Accounting for diagnosis delays or post-endometriosis diagnosis changes in risk factors had a little impact.
Conclusions
This study adds to the evidence that endometriosis is not strongly linked to endometrial cancer risk and that the association with ovarian cancer is robust to misclassification, diagnostic delay, and changes in exposures post-endometriosis diagnosis. Our analysis suggests that confounding and misclassification do not obscure a weak association for endometrial cancer risk, although our results should be replicated.
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