Sex-associated differences in mitochondrial function in human peripheral blood mononuclear cells (PBMCs) and brain

A systematic review and meta-analysis of the acute effects of photobiomodulation therapy on the maximum number of repetitions in resistance exercise in young adults

Photobiomodulation therapy (PBMT) has reportedly improved muscle endurance in healthy individuals. However, the influence of possible moderating factors (light source, body limb, sex, and irradiation dose) on muscle endurance remains unknown. Therefore, this meta-analysis aimed to determine whether potential moderating factors (light source [laser vs. light-emitting diodes (LED)], body limb [upper vs. lower], sex [men vs. women], and irradiated dose]) influence the effects of PBMT on muscular endurance in terms of the maximum number of repetitions in resistance exercise in healthy young adults. The databases, PubMed, Central, Embase, Scopus, SPORTDiscus, and Web of Science (last updated February 5, 2025), were systematically searched for randomized controlled trials. The eligibility criteria were determined using the population, intervention, comparison, and outcome (PICO) method. The main outcome was the maximum number of repetitions, and the data were pooled using the random-effects model and expressed as the mean difference (MD) and 95% confidence interval (CI). The risk of bias was assessed using the RoB 2 tool, and evidence certainty was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines. Twelve studies (n = 346 participants) were included in the analyses. There was an overall effect in favor of PBMT (MD = 3.87 [95% CI: 1.06; 6.69], p = 0.01), compared with the placebo. Compared with the placebo, there was an effect in favor of laser (MD = 3.68 [95% CI: -0.07; 7.44], p = 0.05) and LED (MD = 4.12 [95% CI: -0.13; 8.37], p = 0.057), without difference between the light sources. There was a greater effect of PBMT for the upper limb compared with the lower limb (p = 0.02). Compared with the placebo, there was a significant effect of PBMT for the lower (MD = 1.17 [95% CI: 0.03; 2.32], p = 0.04) and upper limbs (MD = 5.87 [95% CI: 3.11; 8.63], p < 0.001). Compared with the placebo, PBMT had an effect for men (MD = 5.24 [95% CI: 1.61; 8.87], p = 0.005) but not for women (MD = 2.37 [95% CI: -1.78; 6.53], p = 0.26), without difference between sexes. The slope of the meta-regression showed a reduction in effect with increasing dose for the upper limb (slope; p = 0.05; Fig. 7A), but not for the lower limb (slope; p = 0.44; Fig. 7B). In conclusion, PBMT improved muscular endurance in terms of the maximum number of repetitions in healthy young adults. This effect was similar between laser and LED, and to a greater extent in upper limb muscles than in lower limb muscles. Furthermore, PBMT appears to promote greater benefits in men than in women. However, these results should be cautiously interpreted because literature still presents a limited number of studies, and the certainty of the evidence was rated as low or very low.

Mitochondrial DNA copy number and its association with venous thromboembolism in patients with cancer

Venous thromboembolism (VTE) is a common and serious complication among cancer patients. Mitochondrial DNA (mtDNA) copy number is known to influence various cellular pathways involved in cancer development. While an association between reduced mtDNA and VTE risk in non-cancer patients was previously reported, its relationship with VTE in cancer patients remains unclear. Therefore, we aimed to investigate the association between mtDNA copy number and VTE risk in a nested-case control study of 48 patients from the Vienna Cancer and Thrombosis Study (CATS), a prospective observational cohort study. The mtDNA copy number was measured in equally distributed age, sex, cancer type, and stage matched patients with and without VTE using a qPCR-based method. Of the 48 patients, 24 were diagnosed with VTE (median age [IQR] 62 [57-60] years, 54.2 % female) and 24 had no VTE event (median age [IQR] 63 [58-71] years, 54.2 % female). We found that patients who developed VTE had lower mtDNA copy numbers compared to those without VTE (216.73 [167.99-401.39] vs 301.47 [210.66-526.84]). Multivariable analysis adjusting for chronological age, D-dimer, sex, cancer stage and BMI revealed that each 10-unit increase in mtDNA copy number decreased the odds of VTE occurrence by 5.9 % (p = 0.021). Patients with distant metastatic cancer (M1) had lower mtDNA copy numbers than those without distant metastasis at study inclusion (220.34 [172.67-323.70] vs 328.48 [213.89-556.68; p = 0.052). Overall, our findings suggest a potential link between reduced mtDNA copy number and increased VTE risk in cancer patients.

The role of n-3-derived specialised pro-resolving mediators (SPMs) in microglial mitochondrial respiration and inflammation resolution in Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia globally and is characterised by reduced mitochondrial respiration and cortical deposition of amyloid-β plaques and neurofibrillary tangles comprised of hyper-phosphorylated tau. Despite its characterisation more than 110 years ago, the mechanisms by which AD develops are still unclear. Dysregulation of microglial phagocytosis of amyloid-β may play a key role. Microglia are the major innate immune cell of the central nervous system and are critical responders to pro-inflammatory states. Typically, microglia react with a short-lived inflammatory response. However, a dysregulation in the resolution of this microglial response results in the chronic release of inflammatory mediators. This prolongs the state of neuroinflammation, likely contributing to the pathogenesis of AD. In addition, the microglial specialised pro-resolving mediator (SPM) contribution to phagocytosis of amyloid-β is dysregulated in AD. SPMs are derivatives of dietary n-3 polyunsaturated fatty acids (PUFAs) and potentially represent a strategic target for protection against AD progression. However, there is little understanding of how mitochondrial respiration in microglia may be sustained long term by n-3-derived SPMs, and how this affects their clearance of amyloid-β. Here, we re-evaluate the current literature on SPMs in AD and propose that SPMs may improve phagocytosis of amyloid-β by microglia as a result of sustained mitochondrial respiration and allowing a pro-resolution response.

Sex-stratified genome-wide meta-analysis identifies novel loci for cognitive decline in older adults

INTRODUCTION

Many complex traits and diseases show sex-specific biases in clinical presentation and prevalence.

METHODS

To understand sex-specific genetic architecture of cognitive decline across five cognitive domains (attention, memory, executive function, language, and visuospatial function) and global cognitive function, we performed sex-stratified genome-wide meta-analysis in 3021 older adults aged ≥ 65 years (female = 1545, male = 1476) from three prospective cohorts. Gene-based and gene-set enrichment analyses were conducted for each cognitive trait.

RESULTS

We identified a novel genome-wide significant (GWS) intergenic locus for decline of memory in males near RPS23P3 on chromosome 4 (rs6851574: minor allele frequency [MAF] = 0.39, Pmale = 4.10E-08, βmale = 0.19; Pinteraction = 3.76E-04). We also identified a subthreshold GWS locus for decline of executive function on chromosome 12 in females near the NDUFA12 gene, involved in oxidative phosphorylation (rs11107823: MAF = 0.12, Pfemale  = 9.35E-08, βfemale = 0.28; Pinteraction = 7.42E-06).

DISCUSSION

Sex-aware genetic studies can help in the identification of novel genetic loci and enhance sex-specific understanding of cognitive decline.

HIGHLIGHTS

Our genome-wide meta-analysis of single variants identified two new genetic associations, one in males and one in females. The novel male association was observed with the decline of memory in the intergenic region near the RPS23P3 gene on chromosome 4. This intergenic region has previously been implicated in several brain and cognition related traits, including anatomical brain aging, brain shape, and educational attainment. The novel female-specific association was observed with decline in executive function on chromosome 12 near the NDUFA12 gene, which is involved in oxidative phosphorylation. Sex-stratified analyses offer sex-specific understanding of biological pathways involved in cognitive aging.

Analysis of Physiological Oxygen Concentrations in Different Abdominal Fat Layers by Body Mass Index

BACKGROUND

Physiological oxygen concentration in adipose tissue is closely linked to metabolic disorders such as chronic inflammation and insulin resistance. However, the nature of the variation in the oxygen levels of adipose tissue with body mass index (BMI) and depths of abdominal fat remain unclear. Therefore, this study aimed to elucidate the patterns of oxygen concentration in adipose tissue layers according to BMI.

METHODS

In this study, patients undergoing abdominal fat removal surgery were divided into the normal-weight (NW) or overweight-obese (OW) groups based on their BMI. Oxygen concentrations in abdominal superficial (sSAT) and deep subcutaneous adipose tissue (dSAT) were measured. The oxygen consumption rate, mean cell area, and capillary density in both tissue layers were compared between the two groups. Furthermore, the interaction between these three variables, BMI, and adipose tissue oxygen concentration, was analyzed using linear regression.

RESULTS

A total of 42 patients were recruited in this study and we observed that oxygen concentration in the sSAT was significantly lower than in the dSAT, irrespective of BMI. In terms of the oxygen concentration in the dSAT, OW's was significantly lower than that of NW's. Linear regression analysis revealed a significant correlation between dSAT oxygen concentration and BMI, mean adipocyte area, and vascular density.

CONCLUSION

Individuals who are obese have significantly lower oxygen levels in the deep abdominal adipose tissue, and this is influenced by BMI, adipocyte area, and capillary density.

NO LEVEL ASSIGNED

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Mitochondrial respiration in white adipose tissue is dependent on body mass index and tissue location in patients undergoing oncological or parietal digestive surgery

Adipose tissue (AT), is a major endocrine organ that plays a key role in health and disease. However, adipose dysfunctions, especially altered energy metabolism, have been under-investigated as white adipocytes have relatively low mitochondrial density. Nevertheless, recent studies suggest that mitochondria could play a major role in AT disorders and that AT mitochondrial activity could depend on adiposity level and location. This clinical study aimed to evaluate mitochondrial respiration and metabolism in human visceral (vAT) and subcutaneous (scAT) AT and their relationship with body mass index (BMI). This clinical study enrolled 67 patients (30 females/37 males) scheduled for digestive surgery without chemotherapy and parietal infection. BMI ranged from 15.4 to 51.9 kg·m-2 and body composition was estimated by computed tomographic images. Mitochondrial respiration was measured in situ in digitonin-permeabilized AT using high-resolution respirometry and a substrate/inhibitor titration approach. Protein levels of mitochondrial and lipid metabolism key elements were evaluated by Western blot. Maximal mitochondrial respiration correlated negatively with BMI (p < .01) and AT area (p < .001) regardless of the anatomical location. However, oxidative phosphorylation respiration was significantly higher in vAT (2.22 ± 0.15 pmol·sec-1·mg-1) than scAT (1.79 ± 0.17 pmol·sec-1·mg-1) (p < 0.001). In line with oxygraphy results, there were higher levels of mitochondrial respiratory chain complexes in low-BMI patients and vAT. Mitochondrial respiration decreased with increasing BMI in both scAT and vAT, without sex-associated difference. Mitochondrial respiration appeared to be higher in vAT than scAT. These differences were both qualitative and quantitative. Clinical Trials Registration IDNCT05417581.

Mendelian randomization and genetic pleiotropy analysis for the connection between inflammatory bowel disease and Alzheimer's disease

BACKGROUND

The gut-microbiome-brain axis (GMBA) implies the connection between inflammatory bowel disease (IBD) and Alzheimer's disease (AD). We aimed to comprehensively explore the relation between IBD (and its subtypes) and AD, early-onset AD (EOAD) and late-onset AD (LOAD) from a genetic pleiotropy perspective.

METHODS

Relying on summary statistics (N = 472,868 for AD, 185,204 for EOAD, 191,061 for LOAD, 59,957 for IBD, 45,975 for CD, and 40,266 for UC), we first performed Mendelian Randomization to examine the causal association between IBD and AD by leveraging vertical pleiotropy. Then, we estimated global and local genetic correlations, followed by cross-trait association analysis to identify SNPs and genes with horizontal pleiotropy. Particularly, we utilized multi-trait colocalization analysis to assess the role of microbes in the common genetic etiology underlying the two types of diseases. Finally, we conducted functional enrichment analysis for pleiotropic genes.

RESULTS

We discovered suggestively causal relations between IBD (and its subtypes) and EOAD (ORIBD = 1.06 [1.01-1.11], ORCD = 1.05 [1.01-1.10], ORUC = 1.08 [1.01-1.15]) as well as between UC and LOAD (OR = 1.04 [1.01-1.08]), and discovered 44 local regions showing suggestively significant genetic correlations between IBD (and its subtypes) and AD (and EODA and LOAD). We further detected substantial genetic overlap, as characterized by 182  AD-associated, 3 EOAD-associated and 51 LOAD-associated pleiotropic SNPs as well as 291 pleiotropic genes. Pleiotropic genes more likely enriched in the GMBA-relevant tissues such as brain, intestine and esophagus. Moreover, we identified three microorganisms related to these disease pairs, including the Catenibacterium, Clostridia, and Prevotella species.

CONCLUSION

The suggestively causal associations and shared genetic basis between IBD and its subtypes with AD, EOAD and LOAD may commonly drive their co-occurrence, and gut microbes might partly explain the shared genetic etiology. Further studies are warranted to elaborate the possibly biological mechanisms underlying the two types of diseases.

Sexual Dimorphism in Migraine. Focus on Mitochondria

PURPOSE OF REVIEW

Migraine prevalence in females is up to 3 times higher than in males and females show higher frequency, longer duration, and increased severity of headache attacks, but the reason for that difference is not known. This narrative review presents the main aspects of sex dimorphism in migraine prevalence and discusses the role of sex-related differences in mitochondrial homeostasis in that dimorphism. The gender dimension is also shortly addressed.

RECENT FINDINGS

The imbalance between energy production and demand in the brain susceptible to migraine is an important element of migraine pathogenesis. Mitochondria are the main energy source in the brain and mitochondrial impairment is reported in both migraine patients and animal models of human migraine. However, it is not known whether the observed changes are consequences of primary disturbance of mitochondrial homeostasis or are secondary to the migraine-affected hyperexcitable brain. Sex hormones regulate mitochondrial homeostasis, and several reports suggest that the female hormones may act protectively against mitochondrial impairment, contributing to more effective energy production in females, which may be utilized in the mechanisms responsible for migraine progression. Migraine is characterized by several comorbidities that are characterized by sex dimorphism in their prevalence and impairments in mitochondrial functions. Mitochondria may play a major role in sexual dimorphism in migraine through the involvement in energy production, the dependence on sex hormones, and the involvement in sex-dependent comorbidities. Studies on the role of mitochondria in sex dimorphism in migraine may contribute to precise personal therapeutic strategies.

2D 1H sLASER Long-TE and 3D 31P Chemical Shift Imaging at 3 T for Monitoring Fasting-Induced Changes in Brain Tumor Tissue

BACKGROUND

Emerging evidence suggests that fasting could play a key role in cancer treatment. Its metabolic effects on gliomas require further investigation.

PURPOSE

To design a multi-voxel 1H/31P MR-spectroscopic imaging (MRSI) protocol for noninvasive metabolic monitoring of cerebral, fasting-induced changes on an individual patient/tumor level, and to assess its technical reliability/reproducibility.

STUDY TYPE

Prospective.

POPULATION

MRS phantom. Twenty-two patients (mean age = 61, 6 female) with suspected WHO grade II-IV glioma examined before and after 72-hour-fasting prior to biopsy/resection.

FIELD STRENGTH/SEQUENCE

3-T, 1H decoupled 3D 31P MRSI, 2D 1H sLASER MRSI at an echo time of 144 msec, 2D 1H MRSI (as water reference), T1-weighted, T1-weighted contrast-enhanced, T2-weighted, and FLAIR. sLASER and PRESS sequences were used for phantom measurements.

ASSESSMENT

Phantom measurements and spectral simulations were performed with various echo-times for protocol optimization. In vivo spectral analyses were conducted using LCModel and AMARES, obtaining quality/fitting parameters (linewidth, signal-to-noise-ratio, and uncertainty measures of fitting) and metabolite intensities. The volume of glioma sub-regions was calculated and correlated with MRS findings. Ex-vivo spectra of necrotic tumor tissues were obtained using high-resolution magic-angle spinning (HR-MAS) technique.

STATISTICAL TESTS

Wilcoxon signed-rank test, Bland-Altman plots, and coefficient of variation were used for repeatability analysis of quality/fitting parameters and metabolite concentrations. Spearman ρ correlation for the concentration of ketone bodies with volumes of glioma sub-regions was determined. A P-value <0.05 was considered statistically significant.

RESULTS

1H and 31P repeatability measures were highly consistent between the two sessions. β-hydroxybutyrate and acetoacetate were detectable (fitting-uncertainty <50%) in glioma sub-regions of all patients who completed the 72-hour-fasting cycle. β-hydroxybutyrate accumulation was significantly correlated with the necrotic/non-enhancing tumor core volume (ρ = 0.81) and validated using ex-vivo 1H HR-MAS.

DATA CONCLUSION

We propose a comprehensive MRS protocol that may be used for monitoring cerebral, fasting-induced changes in patients with glioma.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 4.

The mitochondrial function of peripheral blood cells in cognitive frailty patients

Background

Cognitive frailty (CF), characterized by the coexistence of physical frailty and cognitive impairment, is linked to increased morbidity and mortality in older adults. While CF has been linked to multiple physiological and lifestyle factors, the underlying biological mechanisms remain poorly understood. This study investigated the risk factors for CF and explored the relationship between mitochondrial function and CF in hospitalized patients.

Methods

A total of 279 hospitalized individuals were recruited from December 2020 to August 2022, conducted comprehensive clinical assessments, and collected peripheral blood samples. CF was evaluated using the Physical Frailty Phenotype and Montreal Cognitive Assessment scales. Nutritional status was assessed with the Mini Nutritional Assessment, and depression was measured using the Geriatric Depression Scale. DNA was obtained from the peripheral blood and interrogated for mitochondrial DNA copy number (mtDNAcn). Peripheral blood mononuclear cells isolated from peripheral blood were examined for respiratory function and reactive oxygen species (ROS) levels. Additionally, plasma samples were analyzed for inflammatory markers and Carnitine Palmitoyltransferase II (CPT2).

Results

Among the participants, 90 were classified as CF and 46 as non-CF. Logistic regression analysis revealed that increased age (OR 1.156, 95% CI 1.064-1.255), lower educational attainment (OR 0.115, 95% CI 0.024-0.550), malnutrition (OR 0.713, 95% CI 0.522-0.973), and higher depression scores (OR 1.345, 95% CI 1.065-1.699) were significantly associated with CF. The independent t tests and Mann-Whitney U tests showed the CF group exhibited impaired mitochondrial function, characterized by reduced mtDNAcn and respiratory activity, coupled with elevated ROS, interleukin-6, and CPT2 levels compared with the non-CF group. After adjusted for age, sex, and BMI, compared with non-CF group, the OR values for the CF group of mtDNAcn and ROS were 0.234 (95% CI = 0.065-0.849) (p = 0.027) and 1.203 (95% CI = 1.075-1.347) (p = 0.001), respectively. The Sensitive analysis showed that the area under curve values for mtDNAcn and ROS were 0.653 and 0.925.

Conclusion

Age, lower educational attainment, malnutrition, and depression are significant risk factors for CF. Moreover, mitochondrial dysfunction, characterized by decreased mtDNAcn, impaired respiratory function and increased ROS levels appears to be a critical phenotype of CF.

Mitochondrial Alterations in Alzheimer's Disease: Insight from the 5xFAD Mouse Model

Mitochondrial dysfunction is increasingly recognized as a key factor in Alzheimer's disease (AD) pathogenesis, but the precise relationship between mitochondrial dynamics and proteinopathies in AD remains unclear. This study investigates the role of mitochondrial dynamics and function in the hippocampal tissue and peripheral blood mononuclear cells (PBMCs) of 5xFAD transgenic mice, as a model of AD. The levels of mitochondrial fusion proteins OPA1 and MFN2 and fission proteins DRP1 and phospho-DRP1 (S616) at 3, 6, and 9 months of age were assessed. Western blot analysis revealed significantly lower levels of OPA1 and MFN2 in the hippocampus of 6- and 9-month-old transgenic (TG) 5xFAD mice compared to controls (CTR), while DRP1 and pDRP1 levels were increased in 9-month-old TG mice. Additionally, MFN2 were decreased in the PBMCs of 9-month-old TG mice, indicating systemic mitochondrial alterations. Ultrastructural analysis of hippocampal tissues showed substantial alterations in mitochondrial morphology, including abnormalities in size and shape, a preponderance of teardrop-shaped mitochondria, and alterations in the somatic mitochondria-ER complex. Notably, mitochondria-associated ER contact sites were more distant in TG mice, suggesting functional impairments. Flow cytometric measurements demonstrated decreased mitochondrial membrane potential and mass, along with increased superoxide production, in the PBMCs of TG mice, particularly at 9 months, highlighting compromised mitochondrial function. Levels of key mitochondrial proteins including VDAC, TOM2O, and mitophagy-related protein PINK1 levels altered in both central and peripheral tissue of TG mice. These findings suggest that mitochondrial dysfunction and altered dynamics are early events in AD development in 5xFAD mice, manifesting in both central and peripheral tissues, and support the notion that mitochondrial abnormalities are an integral component of AD pathology. These insights might lead to the development of targeted therapies that modulate mitochondrial dynamics and function to mitigate AD progression.

Differences in cardiorespiratory fitness by gonadotropin-releasing hormone agonist treatment before and after testosterone in transgender adolescents

There are known sex differences in cardiorespiratory fitness (CRF). Little is known about the impact of pubertal blockade with a gonadotropin-releasing hormone agonist (GnRHa) followed by hormone therapy on CRF for transgender adolescents. We aimed to 1) determine the effect of GnRHa monotherapy on CRF and mitochondrial function and associations with metabolomic profiles and 2) evaluate changes after 1 and 12 mo of testosterone therapy among transgender adolescents. Participants assigned female at birth (n = 19, baseline age of 15.0 ± 1.0 yr) from two groups: GnRHa+ (n = 8) and GnRHa- (n = 11) were examined at baseline and 1- and 12-mo post-testosterone therapy in a longitudinal observational study to assess cardiorespiratory fitness, mitochondrial respiration, and metabolic profile. Fasted morning labs included assessment of metabolomics and peripheral blood mononuclear cell mitochondrial respiration and degree of mitochondrial coupling (respiratory control ratio, RCR). A graded cycle ergometer test was performed. Baseline differences were evaluated between groups. Changes were compared with mixed linear regression models evaluating time (baseline, 1 mo, and 12 mo), group (GnRHa treatment yes/no), and their interaction. At baseline GnRHa+ individuals had higher relative V̇o2peak (30.1 ± 4.83 vs. 25.24 ± 4.47 mL/kg/min, P = 0.042) than GnRHa- individuals. In regression models, GnRHa+ individuals had a significant increase in peak watts (P = 0.011) and total exercise time (P = 0.005) after 12 mo of testosterone (P = 0.012) but not GnRHa- individuals. GnRHa+ individuals have significantly higher RCR under carbohydrate (P = 0.0007) and lipid (P = 0.0002) conditions than GnRHa+ individuals. Pretreatment with GnRHa positively influences peak CRF and mitochondrial respiration in adolescent transgender males undergoing testosterone therapy.NEW & NOTEWORTHY This study demonstrates differences in exercise capacity and mitochondrial respiration at baseline based on whether or not individuals had feminizing puberty blocked. Individuals who had puberty blocked had greater improvements in cardiopulmonary exercise testing parameters after 12 mo of testosterone than those who went through feminizing puberty.

The multiple roles of chronic stress and glucocorticoids in Alzheimer's disease pathogenesis

Chronic stress and the accompanying long-term elevation of glucocorticoids (GCs), the stress hormones of the body, increase the risk and accelerate the progression of Alzheimer's disease (AD). Signatures of AD include intracellular tau (MAPT) tangles, extracellular amyloid β (Aβ) plaques, and neuroinflammation. A growing body of work indicates that stress and GCs initiate cellular processes underlying these pathologies through dysregulation of protein homeostasis and trafficking, mitochondrial bioenergetics, and response to damage-associated stimuli. In this review, we integrate findings from mechanistic studies in rodent and cellular models, wherein defined chronic stress protocols or GC administration have been shown to elicit AD-related pathology. We specifically discuss the effects of chronic stress and GCs on tau pathogenesis, including hyperphosphorylation, aggregation, and spreading, amyloid precursor protein (APP) processing and trafficking culminating in Aβ production, immune priming by proinflammatory cytokines and disease-associated molecular patterns, and alterations to glial cell and blood-brain barrier (BBB) function.

Mitochondrial DNA copy number and neurocognitive outcomes in children

BACKGROUND

Low mitochondria DNA copy number (mtDNAcn) has been linked to cognitive decline. However, the role of mtDNAcn in healthy cognitive development is unclear. We hypothesized early-life mtDNAcn would be associated with children's learning and memory.

METHODS

We quantified mtDNAcn in umbilical cord blood and child blood at ages 5-7 from participants in a prospective birth cohort. We administered the Children's Memory Scale (CMS) at ages 9-14 (N = 342) and the Wechsler Intelligence Scale for Children (WISC-IV) at ages 7 and 9 (N = 457). Associations between mtDNAcn tertiles and CMS and WISC were evaluated with linear regression and linear mixed-effects models, respectively. We examined non-linear associations using generalized additive mixed models.

RESULTS

Relative to the middle tertile of mtDNAcn, lower childhood mtDNAcn was associated with lower WISC Working Memory (β = -2.65, 95% CI [-5.24, -0.06]) and Full-Scale IQ (β = -3.71 [-6.42, -1.00]), and higher CMS Visual Memory (β = 4.70 [0.47, 8.93]). Higher childhood mtDNAcn was linked to higher CMS Verbal Memory (β = 7.75 [2.50, 13.01]). In non-linear models, higher childhood mtDNAcn was associated with lower WISC Verbal Comprehension.

CONCLUSIONS

Our study provides novel evidence that mtDNAcn measured in childhood is associated with children's neurocognitive performance. mtDNAcn may be a marker of healthy child development.

IMPACT

Mitochondrial DNA copy number (mtDNAcn) may serve as a biomarker for early-life neurocognitive performances in the children's population. Both low and high mtDNAcn may contribute to poorer neurocognition, reflected through learning and memory abilities. This research elucidated the importance of investigating mitochondrial biomarkers in healthy populations and facilitated advancements of future studies to better understand the associations between mitochondrial markers and adverse children's health outcomes.

Mitochondrial heterogeneity and crosstalk in aging: Time for a paradigm shift?

The hallmarks of aging have been influential in guiding the biology of aging research, with more recent and growing recognition of the interdependence of these hallmarks on age-related health outcomes. However, a current challenge is personalizing aging trajectories to promote healthy aging, given the diversity of genotypes and lived experience. We suggest that incorporating heterogeneity-including intrinsic (e.g., genetic and structural) and extrinsic (e.g., environmental and exposome) factors and their interdependence of hallmarks-may move the dial. This editorial perspective will focus on one hallmark, namely mitochondrial dysfunction, to exemplify how consideration of heterogeneity and interdependence or crosstalk may reveal new perspectives and opportunities for personalizing aging research. To this end, we highlight heterogeneity within mitochondria as a model.

Multifaceted role of dynamin-related protein 1 in cardiovascular disease: From mitochondrial fission to therapeutic interventions

Mitochondria are central to cellular energy production and metabolic regulation, particularly in cardiomyocytes. These organelles constantly undergo cycles of fusion and fission, orchestrated by key proteins like Dynamin-related Protein 1 (Drp-1). This review focuses on the intricate roles of Drp-1 in regulating mitochondrial dynamics, its implications in cardiovascular health, and particularly in myocardial infarction. Drp-1 is not merely a mediator of mitochondrial fission; it also plays pivotal roles in autophagy, mitophagy, apoptosis, and necrosis in cardiac cells. This multifaceted functionality is often modulated through various post-translational alterations, and Drp-1's interaction with intracellular calcium (Ca2 + ) adds another layer of complexity. We also explore the pathological consequences of Drp-1 dysregulation, including increased reactive oxygen species (ROS) production and endothelial dysfunction. Furthermore, this review delves into the potential therapeutic interventions targeting Drp-1 to modulate mitochondrial dynamics and improve cardiovascular outcomes. We highlight recent findings on the interaction between Drp-1 and sirtuin-3 and suggest that understanding this interaction may open new avenues for therapeutically modulating endothelial cells, fibroblasts, and cardiomyocytes. As the cardiovascular system increasingly becomes the focal point of aging and chronic disease research, understanding the nuances of Drp-1's functionality can lead to innovative therapeutic approaches.

The association of circulating bioenergetic metabolites with healthy human aging

Aging is an inevitable and gradual decline in several biological functions. Mitochondrial dysfunction is one of the most important hallmarks of aging. In this context, alterations in metabolites associated with mitochondrial dysfunction may serve as a significant biomarker. This study aimed to investigate the existence of a relationship between the key metabolites involved in bioenergetics metabolism and aging. 53 volunteers ranged 20-85 years participated in the study. We tested the association between different tricarboxylic acid (TCA) cycle metabolites, fatty acid metabolism, and amino acid metabolism with age, sex, body composition, and proxy markers of aging such as walking speed, grip strength and chair test. We found that lactic acid negatively correlated with age while several fatty acid metabolites, such as azelaic, sebacic, and linoleic acids, showed positive correlations with age (p < 0.05). Sex-specific trends, such as glycerol, and dodecanoic acid, were also observed for certain metabolites. Furthermore, citric acid levels were found to have a significant association with physical function and body composition measures. Participants with higher citric acid levels displayed improved performance in physical tests and favorable body composition indices. Additionally, fumaric acid and adipic acid showed positive correlations with fat-free body mass, while sebacic acid was negatively associated with measures of fat mass. These findings underscore the importance of understanding the role of circulating bioenergetics metabolites with age, sex variations, and their potential implications in body composition and physical performance.

Markers of Mitochondrial Function and DNA Repair Associated with Physical Function in Centenarians

Mitochondrial dysfunction and genomic instability are key hallmarks of aging. The aim of this study was to evaluate whether maintenance of physical capacities at very old age is associated with key hallmarks of aging. To investigate this, we measured mitochondrial bioenergetics, mitochondrial DNA (mtDNA) copy number and DNA repair capacity in peripheral blood mononuclear cells from centenarians. In addition, circulating levels of NAD+/NADH, brain-derived neurotrophic factor (BDNF) and carbonylated proteins were measured in plasma and these parameters were correlated to physical capacities. Centenarians without physical disabilities had lower mitochondrial respiration values including ATP production, reserve capacity, maximal respiration and non-mitochondrial oxygen-consumption rate and had higher mtDNA copy number than centenarians with moderate and severe disabilities (p < 0.05). In centenarian females, grip strength had a positive association with mtDNA copy number (p < 0.05), and a borderline positive trend for activity of the central DNA repair enzyme, APE 1 (p = 0.075), while a negative trend was found with circulating protein carbonylation (p = 0.07) in the entire cohort. Lastly, a trend was observed for a negative association between BDNF and activity of daily living disability score (p = 0.06). Our results suggest that mechanisms involved in maintaining mitochondrial function and genomic stability may be associated with maintenance of physical function in centenarians.

Pre-exercise cryotherapy reduces myoglobin and creatine kinase levels after eccentric muscle stress in young women

Introduction: The aim of this study was to investigate the effect of pre-exercise whole-body cryotherapy (WBC) on muscle damage indicators following eccentric treadmill exercise in young women. Methods: Twenty-seven participants underwent two 1-h downhill treadmill runs, replicating 60% of their maximal oxygen uptake, with a 4-week intermission for recovery and treatment application. In this intermission, one group underwent 20 sessions of WBC, delivered five times a week at -120°C for 3 min each, while the comparison group received no such treatment. Markers of muscle injury-serum myoglobin concentration, creatine kinase and lactate dehydrogenase activity and also uric acid, and cell-free DNA concentration-were measured before and after downhill runs. Results: The study observed a notable reduction in post-exercise myoglobin and CK levels in the WBC group after the second running session. Discussion: The results suggest that WBC can have a protective effects against muscle damage resulting from eccentric exercise.

In vivo translocator protein in females with autism spectrum disorder: a pilot study

Sex-based differences in the prevalence of autism spectrum disorder (ASD) are well-documented, with a male-to-female ratio of approximately 4:1. The clinical presentation of the core symptoms of ASD can also vary between sexes. Previously, positron emission tomography (PET) studies have identified alterations in the in vivo levels of translocator protein (TSPO)-a mitochondrial protein-in primarily or only male adults with ASD, with our group reporting lower TSPO relative to whole brain mean in males with ASD. However, whether in vivo TSPO levels are altered in females with ASD, specifically, is unknown. This is the first pilot study to measure in vivo TSPO in the brain in adult females with ASD using [11C]PBR28 PET-magnetic resonance imaging (MRI). Twelve adult females with ASD and 10 age- and TSPO genotype-matched controls (CON) completed one or two [11C]PBR28 PET-MRI scans. Females with ASD exhibited elevated [11C]PBR28 standardized uptake value ratio (SUVR) in the midcingulate cortex and splenium of the corpus callosum compared to CON. No brain area showed lower [11C]PBR28 SUVR in females with ASD compared to CON. Test-retest over several months showed stable [11C]PBR28 SUVR across time in both groups. Elevated regional [11C]PBR28 SUVR in females with ASD stand in stark contrast to our previous findings of lower regional [11C]PBR28 SUVR in males with ASD. Preliminary evidence of regionally elevated mitochondrial protein TSPO relative to whole brain mean in ASD females may reflect neuroimmuno-metabolic alterations specific to females with ASD.

Decreased mitochondrial respiration associates with frailty in community-dwelling older adults

Aging population has led to an increased prevalence of chronic and degenerative pathologies. A manifestation of unhealthy aging is frailty, a geriatric syndrome that implies a non-specific state of greater vulnerability. Currently, methods for frailty diagnosis are based exclusively on clinical observation. The aim of this study is to determine whether the bioenergetic capacity defined as mitochondrial oxygen consumption rate (OCR) of peripheral circulation mononuclear cells (PBMC) associates with the frailty phenotype in older adults and with their nutritional status. This is a cross-sectional analytic study of 58 participants 70 years and older, 18 frail and 40 non-frail adults, from the ALEXANDROS cohort study, previously described. Participants were characterized through sociodemographic and anthropometric assessments. Frail individuals displayed a higher frequency of osteoporosis and depression. The mean age of the participants was 80.2 ± 5.2 years, similar in both groups of men and women. Regarding the nutritional status defined as the body mass index, most non-frail individuals were normal or overweight, while frail participants were mostly overweight or obese. We observed that OCR was significantly decreased in frail men (p < 0.01). Age was also associated with significant differences in oxygen consumption in frail patients, with lower oxygen consumption being observed in those over 80 years of age. Therefore, the use of PBMC can result in an accessible fingerprint that may identify initial stages of frailty in a minimally invasive way.

Peripheral Blood Cells From Older Adults Exhibit Sex-Associated Differences in Mitochondrial Function

Blood-based mitochondrial bioenergetic profiling is a feasible, economical, and minimally invasive approach that can be used to examine mitochondrial function and energy metabolism in human subjects. In this study, we use 2 complementary respirometric techniques to evaluate mitochondrial bioenergetics in both intact and permeabilized peripheral blood mononuclear cells (PBMCs) and platelets to examine sex dimorphism in mitochondrial function among older adults. Employing equal numbers of PBMCs and platelets to assess mitochondrial bioenergetics, we observe significantly higher respiration rates in female compared to male participants. Mitochondrial bioenergetic differences remain significant after controlling for independent parameters including demographic parameters (age, years of education), and cognitive parameters (mPACC5, COGDX). Our study illustrates that circulating blood cells, immune cells in particular, have distinctly different mitochondrial bioenergetic profiles between females and males. These differences should be taken into account as blood-based bioenergetic profiling is now commonly used to understand the role of mitochondrial bioenergetics in human health and aging.

Lack of detectable sex differences in the mitochondrial function of Caenorhabditis elegans

BACKGROUND

Sex differences in mitochondrial function have been reported in multiple tissue and cell types. Additionally, sex-variable responses to stressors including environmental pollutants and drugs that cause mitochondrial toxicity have been observed. The mechanisms that establish these differences are thought to include hormonal modulation, epigenetic regulation, double dosing of X-linked genes, and the maternal inheritance of mtDNA. Understanding the drivers of sex differences in mitochondrial function and being able to model them in vitro is important for identifying toxic compounds with sex-variable effects. Additionally, understanding how sex differences in mitochondrial function compare across species may permit insight into the drivers of these differences, which is important for basic biology research. This study explored whether Caenorhabditis elegans, a model organism commonly used to study stress biology and toxicology, exhibits sex differences in mitochondrial function and toxicant susceptibility. To assess sex differences in mitochondrial function, we utilized four male enriched populations (N2 wild-type male enriched, fog-2(q71), him-5(e1490), and him-8(e1498)). We performed whole worm respirometry and determined whole worm ATP levels and mtDNA copy number. To probe whether sex differences manifest only after stress and inform the growing use of C. elegans as a mitochondrial health and toxicologic model, we also assessed susceptibility to a classic mitochondrial toxicant, rotenone.

RESULTS

We detected few to no large differences in mitochondrial function between C. elegans sexes. Though we saw no sex differences in vulnerability to rotenone, we did observe sex differences in the uptake of this lipophilic compound, which may be of interest to those utilizing C. elegans as a model organism for toxicologic studies. Additionally, we observed altered non-mitochondrial respiration in two him strains, which may be of interest to other researchers utilizing these strains.

CONCLUSIONS

Basal mitochondrial parameters in male and hermaphrodite C. elegans are similar, at least at the whole-organism level, as is toxicity associated with a mitochondrial Complex I inhibitor, rotenone. Our data highlights the limitation of using C. elegans as a model to study sex-variable mitochondrial function and toxicological responses.

Mechanisms of sex differences in Alzheimer's disease

Alzheimer's disease (AD) and the mechanisms underlying its etiology and progression are complex and multifactorial. The higher AD risk in women may serve as a clue to better understand these complicated processes. In this review, we examine aspects of AD that demonstrate sex-dependent effects and delve into the potential biological mechanisms responsible, compiling findings from advanced technologies such as single-cell RNA sequencing, metabolomics, and multi-omics analyses. We review evidence that sex hormones and sex chromosomes interact with various disease mechanisms during aging, encompassing inflammation, metabolism, and autophagy, leading to unique characteristics in disease progression between men and women.

Childhood adverse life events and skeletal muscle mitochondrial function

Social stress experienced in childhood is associated with adverse health later in life. Mitochondrial function has been implicated as a mechanism for how stressful life events "get under the skin" to influence physical well-being. Using data from the Study of Muscle, Mobility, and Aging (n = 879, 59% women), linear models examined whether adverse childhood events (i.e., physical abuse) were associated with two measures of skeletal muscle mitochondrial energetics in older adults: (i) maximal adenosine triphosphate production (ATPmax) and (ii) maximal state 3 respiration (Max OXPHOS). Forty-five percent of the sample reported experiencing one or more adverse childhood events. After adjustment, each additional event was associated with -0.08 SD (95% confidence interval = -0.13, -0.02) lower ATPmax. No association was observed with Max OXPHOS. Adverse childhood events are associated with lower ATP production in later life. Findings indicate that mitochondrial function may be a mechanism for understanding how early social stress influences health in later life.

Sex-specific associations of serum cortisol with brain biomarkers of Alzheimer's risk

Emerging evidence implicates chronic psychological stress as a risk factor for Alzheimer's disease (AD). Herein, we examined the relationships between serum cortisol and multimodality brain AD biomarkers in 277 cognitively normal midlife individuals at risk for AD. Overall, higher cortisol was associated with lower total brain volume, lower glucose metabolism (CMRglc) in frontal cortex, and higher β-amyloid (Aβ) load in AD-vulnerable regions; and marginally associated with phosphocreatine to ATP ratios (PCr/ATP) in precuneus and parietal regions. Sex-specific modification effects were noted: in women, cortisol exhibited stronger associations with Aβ load and frontal CMRglc, the latter being more pronounced postmenopause. In men, cortisol exhibited stronger associations with gray matter volume and PCr/ATP measures. Higher cortisol was associated with poorer delayed memory in men but not in women. Results were adjusted for age, Apolipoprotein E (APOE) epsilon 4 status, midlife health factors, and hormone therapy use. These results suggest sex-specific neurophysiological responses to stress, and support a role for stress reduction in AD prevention.

Bioenergetic signatures of neurodevelopmental regression

Background: Studies have linked autism spectrum disorder (ASD) to physiological abnormalities including mitochondrial dysfunction. Mitochondrial dysfunction may be linked to a subset of children with ASD who have neurodevelopmental regression (NDR). We have developed a cell model of ASD which demonstrates a unique mitochondrial profile with mitochondrial respiration higher than normal and sensitive to physiological stress. We have previously shown similar mitochondrial profiles in individuals with ASD and NDR. Methods: Twenty-six ASD individuals without a history of NDR (ASD-NoNDR) and 15 ASD individuals with a history of NDR (ASD-NDR) were recruited from 34 families. From these families, 30 mothers, 17 fathers and 5 typically developing (TD) siblings participated. Mitochondrial respiration was measured in peripheral blood mononuclear cells (PBMCs) with the Seahorse 96 XF Analyzer. PBMCs were exposed to various levels of physiological stress for 1 h prior to the assay using 2,3-dimethoxy-1,4-napthoquinone. Results: ASD-NDR children were found to have higher respiratory rates with mitochondria that were more sensitive to physiological stress as compared to ASD-NoNDR children, similar to our cellular model of NDR. Differences in mitochondrial respiration between ASD-NDR and TD siblings were similar to the differences between ASD-NDR and ASD-NoNDR children. Interesting, parents of children with ASD and NDR demonstrated patterns of mitochondrial respiration similar to their children such that parents of children with ASD and NDR demonstrated elevated respiratory rates with mitochondria that were more sensitive to physiological stress. In addition, sex differences were seen in ASD children and parents. Age effects in parents suggested that mitochondria of older parents were more sensitive to physiological stress. Conclusion: This study provides further evidence that children with ASD and NDR may have a unique type of mitochondrial physiology that may make them susceptible to physiological stressors. Identifying these children early in life before NDR occurs and providing treatment to protect mitochondrial physiology may protect children from experiencing NDR. The fact that parents also demonstrate mitochondrial respiration patterns similar to their children implies that this unique change in mitochondrial physiology may be a heritable factor (genetic or epigenetic), a result of shared environment, or both.

Age-related changes in energy metabolism in peripheral mononuclear blood cells (PBMCs) and the brains of cognitively healthy seniors

Mitochondrial dysfunction is a hallmark of cellular senescence and many age-related neurodegenerative diseases. We therefore investigated the relationship between mitochondrial function in peripheral blood cells and cerebral energy metabolites in young and older sex-matched, physically and mentally healthy volunteers. Cross-sectional observational study involving 65 young (26.0 ± 0.49 years) and 65 older (71.7 ± 0.71 years) women and men recruited. Cognitive health was evaluated using established psychometric methods (MMSE, CERAD). Blood samples were collected and analyzed, and fresh peripheral blood mononuclear cells (PBMCs) were isolated. Mitochondrial respiratory complex activity was measured using a Clarke electrode. Adenosine triphosphate (ATP) and citrate synthase activity (CS) were determined by bioluminescence and photometrically. N-aspartyl-aspartate (tNAA), ATP, creatine (Cr), and phosphocreatine (PCr) were quantified in brains using 1H- and 31P-magnetic resonance spectroscopic imaging (MRSI). Levels of insulin-like growth factor 1 (IGF-1) were determined using a radio-immune assay (RIA). Complex IV activity (CIV) (- 15%) and ATP levels (- 11%) were reduced in PBMCs isolated from older participants. Serum levels of IGF-1 were significantly reduced (- 34%) in older participants. Genes involved in mitochondrial activity, antioxidant mechanisms, and autophagy were unaffected by age. tNAA levels were reduced (- 5%), Cr (+ 11%), and PCr (+ 14%) levels were increased, and ATP levels were unchanged in the brains of older participants. Markers of energy metabolism in blood cells did not significantly correlate with energy metabolites in the brain. Age-related bioenergetic changes were detected in peripheral blood cells and the brains of healthy older people. However, mitochondrial function in peripheral blood cells does not reflect energy related metabolites in the brain. While ATP levels in PBMCs may be be a valid marker for age-related mitochondrial dysfunction in humans, cerebral ATP remained constant.

Ex Vivo 13C-Metabolic Flux Analysis of Porcine Circulating Immune Cells Reveals Cell Type-Specific Metabolic Patterns and Sex Differences in the Pentose Phosphate Pathway

In general, females present with stronger immune responses than males, but scarce data are available on sex-specific differences in immunometabolism. In this study, we characterized porcine peripheral blood mononuclear cell (PBMC) and granulocyte energy metabolism using a Bayesian 13C-metabolic flux analysis, which allowed precise determination of the glycolytic, pentose phosphate pathway (PPP), and tricarboxylic acid cycle (TCA) fluxes, together with an assessment of the superoxide anion radical (O2•-) production and mitochondrial O2 consumption. A principal component analysis allowed for identifying the cell type-specific patterns of metabolic plasticity. PBMCs displayed higher TCA cycle activity, especially glutamine-derived aspartate biosynthesis, which was directly related to mitochondrial respiratory activity and inversely related to O2•- production. In contrast, the granulocytes mainly utilized glucose via glycolysis, which was coupled to oxidative PPP utilization and O2•- production rates. The granulocytes of the males had higher oxidative PPP fluxes compared to the females, while the PBMCs of the females displayed higher non-oxidative PPP fluxes compared to the males associated with the T helper cell (CD3+CD4+) subpopulation of PBMCs. The observed sex-specific differences were not directly attributable to sex steroid plasma levels, but we detected an inverse correlation between testosterone and aldosterone plasma levels and showed that aldosterone levels were related with non-oxidative PPP fluxes of both cell types.

International society of sports nutrition position stand: nutritional concerns of the female athlete

Based on a comprehensive review and critical analysis of the literature regarding the nutritional concerns of female athletes, conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society: 1. Female athletes have unique and unpredictable hormone profiles, which influence their physiology and nutritional needs across their lifespan. To understand how perturbations in these hormones affect the individual, we recommend that female athletes of reproductive age should track their hormonal status (natural, hormone driven) against training and recovery to determine their individual patterns and needs and peri and post-menopausal athletes should track against training and recovery metrics to determine the individuals' unique patterns. 2. The primary nutritional consideration for all athletes, and in particular, female athletes, should be achieving adequate energy intake to meet their energy requirements and to achieve an optimal energy availability (EA); with a focus on the timing of meals in relation to exercise to improve training adaptations, performance, and athlete health. 3. Significant sex differences and sex hormone influences on carbohydrate and lipid metabolism are apparent, therefore we recommend first ensuring athletes meet their carbohydrate needs across all phases of the menstrual cycle. Secondly, tailoring carbohydrate intake to hormonal status with an emphasis on greater carbohydrate intake and availability during the active pill weeks of oral contraceptive users and during the luteal phase of the menstrual cycle where there is a greater effect of sex hormone suppression on gluconogenesis output during exercise. 4. Based upon the limited research available, we recommend that pre-menopausal, eumenorrheic, and oral contraceptives using female athletes should aim to consume a source of high-quality protein as close to beginning and/or after completion of exercise as possible to reduce exercise-induced amino acid oxidative losses and initiate muscle protein remodeling and repair at a dose of 0.32-0.38 g·kg-1. For eumenorrheic women, ingestion during the luteal phase should aim for the upper end of the range due to the catabolic actions of progesterone and greater need for amino acids. 5. Close to the beginning and/or after completion of exercise, peri- and post-menopausal athletes should aim for a bolus of high EAA-containing (~10 g) intact protein sources or supplements to overcome anabolic resistance. 6. Daily protein intake should fall within the mid- to upper ranges of current sport nutrition guidelines (1.4-2.2 g·kg-1·day-1) for women at all stages of menstrual function (pre-, peri-, post-menopausal, and contraceptive users) with protein doses evenly distributed, every 3-4 h, across the day. Eumenorrheic athletes in the luteal phase and peri/post-menopausal athletes, regardless of sport, should aim for the upper end of the range. 7. Female sex hormones affect fluid dynamics and electrolyte handling. A greater predisposition to hyponatremia occurs in times of elevated progesterone, and in menopausal women, who are slower to excrete water. Additionally, females have less absolute and relative fluid available to lose via sweating than males, making the physiological consequences of fluid loss more severe, particularly in the luteal phase. 8. Evidence for sex-specific supplementation is lacking due to the paucity of female-specific research and any differential effects in females. Caffeine, iron, and creatine have the most evidence for use in females. Both iron and creatine are highly efficacious for female athletes. Creatine supplementation of 3 to 5 g per day is recommended for the mechanistic support of creatine supplementation with regard to muscle protein kinetics, growth factors, satellite cells, myogenic transcription factors, glycogen and calcium regulation, oxidative stress, and inflammation. Post-menopausal females benefit from bone health, mental health, and skeletal muscle size and function when consuming higher doses of creatine (0.3 g·kg-1·d-1). 9. To foster and promote high-quality research investigations involving female athletes, researchers are first encouraged to stop excluding females unless the primary endpoints are directly influenced by sex-specific mechanisms. In all investigative scenarios, researchers across the globe are encouraged to inquire and report upon more detailed information surrounding the athlete's hormonal status, including menstrual status (days since menses, length of period, duration of cycle, etc.) and/or hormonal contraceptive details and/or menopausal status.

Childhood adverse life events and skeletal muscle mitochondrial function

Social stress experienced in childhood is associated with adverse health later in life. Mitochondrial function has been implicated as a mechanism for how stressful life events "get under the skin" to influence physical wellbeing. Using data from the Study of Muscle, Mobility and Aging (n=879, 59% women), linear models examined whether adverse childhood events (i.e., physical abuse) were associated with two measures of skeletal muscle mitochondrial energetics in older adults: (1) maximal adenosine triphosphate production (ATP max ) and (2) maximal state 3 respiration (Max OXPHOS). Forty-five percent of the sample reported experiencing 1+ adverse childhood event. After adjustment, each additional event was associated with -0.07 SD (95% CI= - 0.12, -0.01) lower ATP max . No association was observed with Max OXPHOS. Adverse childhood events are associated with lower ATP production in later life. Findings indicate that mitochondrial function may be a mechanism in understanding how early social stress influences health in later life.

Randomized controlled trial investigating potential effects of relaxation on mitochondrial function in immune cells: A pilot experiment

This study aimed to investigate the effect of a relaxation response induced by hypnosis on the mitochondrial energy production of immune cells compared to an everyday relaxing situation. Chronically stressed individuals (88% women) with at least moderate suggestibility were randomized to a hypnosis (20 min relaxation hypnosis; n = 20) or a control condition (20 min documentary; n = 22). Before and after intervention, peripheral blood was collected. The primary outcomes were mitochondrial respiration and density in immune cells measured by high-resolution respirometry and citrate synthase activity assays. As secondary outcome, perceived stress, anxiety, and depressive mood were assessed. The intervention led to no significant Group × Time effects on mitochondrial bioenergetic parameters but a significant Time effect (ηp2 = .09 -.10). Thus, there were no differences in the experimental conditions concerning the measured parameters of mitochondrial bioenergetics. Exploratory subanalyses indicated that stress, anxiety, and depressive mood were linked to lower mitochondrial respiration. Individuals with higher anxiety had less decrease in routine respiration over time than those with lower anxiety (ηp2 = .09). This study explores the effects of relaxation in the form of hypnosis compared to watching a video on the energy metabolism of immune cells. Relaxation, whether in targeted (hypnosis) or untargeted (documentary) form, affected mitochondrial respiration. Further research should focus on the long-term effects of relaxation on bioenergetics. The trial was retrospectively registered on 07/12/2021, DRKS00027356, https://drks.de/search/de/trial/DRKS00027356.

Remdesivir increases mtDNA copy number causing mild alterations to oxidative phosphorylation

SARS-CoV-2 causes the severe respiratory disease COVID-19. Remdesivir (RDV) was the first fast-tracked FDA approved treatment drug for COVID-19. RDV acts as an antiviral ribonucleoside (adenosine) analogue that becomes active once it accumulates intracellularly. It then diffuses into the host cell and terminates viral RNA transcription. Previous studies have shown that certain nucleoside analogues unintentionally inhibit mitochondrial RNA or DNA polymerases or cause mutational changes to mitochondrial DNA (mtDNA). These past findings on the mitochondrial toxicity of ribonucleoside analogues motivated us to investigate what effects RDV may have on mitochondrial function. Using in vitro and in vivo rodent models treated with RDV, we observed increases in mtDNA copy number in Mv1Lu cells (35.26% increase ± 11.33%) and liver (100.27% increase ± 32.73%) upon treatment. However, these increases only resulted in mild changes to mitochondrial function. Surprisingly, skeletal muscle and heart were extremely resistant to RDV treatment, tissues that have preferentially been affected by other nucleoside analogues. Although our data suggest that RDV does not greatly impact mitochondrial function, these data are insightful for the treatment of RDV for individuals with mitochondrial disease.

The effect of hypomagnetic field on survival and mitochondrial functionality of active Paramacrobiotus experimentalis females and males of different age

Even for tardigrades, often called the toughest animals on Earth, a hypomagnetic field (HMF) is an extreme environment. However, studies on the effect of HMF on tardigrades and other invertebrates are scarce. Mitochondria play an important role in an organism's response to extreme conditions. The effect of HMF on the mitochondrial inner membrane potential (Δψ), a well-known marker of mitochondria functionality, shows that mitochondria are very sensitive to HMF. To measure the HMF effect on Paramacrobiotus experimentalis, we calculated the tardigrade survival rate and Δψ level after HMF treatments of different durations. We also estimated the relationship between the age and sex of the tardigrade and the HMF effect. We observed age- and sex-related differences in Δψ and found that Δψ changes after HMF treatment were dependent on its duration as well as the animal's age and sex. Furthermore, active P. experimentalis individuals displayed a high survival rate after HMF treatment. The data may contribute to the understanding of tardigrade aging and their resistance to extreme conditions including HMF, which in turn may be useful for future space explorations.

Peri-Operative Kinetics of Plasma Mitochondrial DNA Levels during Living Donor Kidney Transplantation

During ischemia and reperfusion injury (IRI), mitochondria may release mitochondrial DNA (mtDNA). mtDNA can serve as a propagator of further injury but in specific settings has anti-inflammatory capacities as well. Therefore, the aim of this study was to study the perioperative dynamics of plasma mtDNA during living donor kidney transplantation (LDKT) and its potential as a marker of graft outcome. Fifty-six donor-recipient couples from the Volatile Anesthetic Protection of Renal Transplants-1 (VAPOR-1) trial were included. Systemic venous, systemic arterial, and renal venous samples were taken at multiple timepoints during and after LDKT. Levels of mtDNA genes changed over time and between vascular compartments. Several donor, recipient, and transplantation-related variables significantly explained the course of mtDNA genes over time. mtDNA genes predicted 1-month and 24-month estimated glomerular filtration rate (eGFR) and acute rejection episodes in the two-year follow-up period. To conclude, mtDNA is released in plasma during the process of LDKT, either from the kidney or from the whole body in response to transplantation. While circulating mtDNA levels positively and negatively predict post-transplantation outcomes, the exact mechanisms and difference between mtDNA genes are not yet understood and need further exploration.

SS-31 alleviated nociceptive responses and restored mitochondrial function in a headache mouse model via Sirt3/Pgc-1α positive feedback loop

Migraine is the second highest cause of disability worldwide, bringing a huge socioeconomic burden. Improving mitochondrial function has promise as an effective treatment strategy for migraine. Szeto-Schiller peptide (SS-31) is a new mitochondria-targeted tetrapeptide molecule that has been shown to suppress the progression of diseases by restoring mitochondrial function, including renal disease, cardiac disease, and neurodegenerative disease. However, whether SS-31 has a therapeutic effect on migraine remains unclear. The aim of this study is to clarify the treatment of SS-31 for headache and its potential mechanisms. Here we used a mouse model induced by repeated dural infusion of inflammatory soup (IS), and examined roles of Sirt3/Pgc-1α positive feedback loop in headache pathogenesis and mitochondrial function. Our results showed that repeated IS infusion impaired mitochondrial function, mitochondrial ultrastructure and mitochondrial homeostasis in the trigeminal nucleus caudalis (TNC). These IS-induced damages in TNC were reversed by SS-31. In addition, IS-induced nociceptive responses were simultaneously alleviated. The effects of SS-31 on mitochondrial function and mitochondrial homeostasis (mainly mitochondrial biogenesis) were attenuated partially by the inhibitor of Sirt3/Pgc-1α. Overexpression of Sirt3/Pgc-1α increased the protein level of each other. These results indicated that SS-31 alleviated nociceptive responses and restored mitochondrial function in an IS-induced headache mouse model via Sirt3/Pgc-1α positive feedback loop. SS-31 has the potential to be an effective drug candidate for headache treatment.

Succinate prodrugs as treatment for acute metabolic crisis during fluoroacetate intoxication in the rat

Sodium fluoroacetate (FA) is a metabolic poison that systemically inhibits the tricarboxylic acid (TCA) cycle, causing energy deficiency and ultimately multi-organ failure. It poses a significant threat to society because of its high toxicity, potential use as a chemical weapon and lack of effective antidotal therapy. In this study, we investigated cell-permeable succinate prodrugs as potential treatment for acute FA intoxication. We hypothesized that succinate prodrugs would bypass FA-induced mitochondrial dysfunction, provide metabolic support, and prevent metabolic crisis during acute FA intoxication. To test this hypothesis, rats were exposed to FA (0.75 mg/kg) and treated with the succinate prodrug candidate NV354. Treatment efficacy was evaluated based on cardiac and cerebral mitochondrial respiration, mitochondrial content, metabolic profiles and tissue pathology. In the heart, FA increased concentrations of the TCA metabolite citrate (+ 4.2-fold, p < 0.01) and lowered ATP levels (- 1.9-fold, p < 0.001), confirming the inhibition of the TCA cycle by FA. High-resolution respirometry of cardiac mitochondria further revealed an impairment of mitochondrial complex V (CV)-linked metabolism, as evident by a reduced phosphorylation system control ratio (- 41%, p < 0.05). The inhibition of CV-linked metabolism is a novel mechanism of FA cardiac toxicity, which has implications for drug development and which NV354 was unable to counteract at the given dose. In the brain, FA induced the accumulation of β-hydroxybutyrate (+ 1.4-fold, p < 0.05) and the reduction of mitochondrial complex I (CI)-linked oxidative phosphorylation (OXPHOSCI) (- 20%, p < 0.01), the latter of which was successfully alleviated by NV354. This promising effect of NV354 warrants further investigations to determine its potential neuroprotective effects.

Effect of N-Acetylcysteine on Sleep: Impacts of Sex and Time of Day

Non-rapid eye movement sleep (NREMS) is accompanied by a decrease in cerebral metabolism, which reduces the consumption of glucose as a fuel source and decreases the overall accumulation of oxidative stress in neural and peripheral tissues. Enabling this metabolic shift towards a reductive redox environment may be a central function of sleep. Therefore, biochemical manipulations that potentiate cellular antioxidant pathways may facilitate this function of sleep. N-acetylcysteine increases cellular antioxidant capacity by serving as a precursor to glutathione. In mice, we observed that intraperitoneal administration of N-acetylcysteine at a time of day when sleep drive is naturally high accelerated the onset of sleep and reduced NREMS delta power. Additionally, N-acetylcysteine administration suppressed slow and beta electroencephalographic (EEG) activities during quiet wake, further demonstrating the fatigue-inducing properties of antioxidants and the impact of redox balance on cortical circuit properties related to sleep drive. These results implicate redox reactions in the homeostatic dynamics of cortical network events across sleep/wake cycles, illustrating the value of timing antioxidant administration relative to sleep/wake cycles. A systematic review of the relevant literature, summarized herein, indicates that this "chronotherapeutic hypothesis" is unaddressed within the clinical literature on antioxidant therapy for brain disorders such as schizophrenia. We, therefore, advocate for studies that systematically address the relationship between the time of day at which an antioxidant therapy is administered relative to sleep/wake cycles and the therapeutic benefit of that antioxidant treatment in brain disorders.

Progranulin deficiency results in sex-dependent alterations in microglia in response to demyelination

Heterozygous mutations in the granulin (GRN) gene, resulting in the haploinsufficiency of the progranulin (PGRN) protein, is a leading cause of frontotemporal lobar degeneration (FTLD). Complete loss of the PGRN protein causes neuronal ceroid lipofuscinosis (NCL), a lysosomal storage disorder. Polymorphisms in the GRN gene have also been associated with several other neurodegenerative diseases, including Alzheimer's disease (AD), and Parkinson's disease (PD). PGRN deficiency has been shown to cause myelination defects previously, but how PGRN regulates myelination is unknown. Here, we report that PGRN deficiency leads to a sex-dependent myelination defect with male mice showing more severe demyelination in response to cuprizone treatment. This is accompanied by exacerbated microglial proliferation and activation in the male PGRN-deficient mice. Interestingly, both male and female PGRN-deficient mice show sustained microglial activation after cuprizone removal and a defect in remyelination. Specific ablation of PGRN in microglia results in similar sex-dependent phenotypes, confirming a microglial function of PGRN. Lipid droplets accumulate in microglia specifically in male PGRN-deficient mice. RNA-seq analysis and mitochondrial function assays reveal key differences in oxidative phosphorylation in male versus female microglia under PGRN deficiency. A significant decrease in myelination and accumulation of myelin debris and lipid droplets in microglia were found in the corpus callosum regions of FTLD patients with GRN mutations. Taken together, our data support that PGRN deficiency leads to sex-dependent alterations in microglia with subsequent myelination defects.

Drosophila melanogaster as a model to study age and sex differences in brain injury and neurodegeneration after mild head trauma

Repetitive physical insults to the head, including those that elicit mild traumatic brain injury (mTBI), are a known risk factor for a variety of neurodegenerative conditions including Alzheimer's disease (AD), Parkinson's disease (PD), and chronic traumatic encephalopathy (CTE). Although most individuals who sustain mTBI typically achieve a seemingly full recovery within a few weeks, a subset experience delayed-onset symptoms later in life. As most mTBI research has focused on the acute phase of injury, there is an incomplete understanding of mechanisms related to the late-life emergence of neurodegeneration after early exposure to mild head trauma. The recent adoption of Drosophila-based brain injury models provides several unique advantages over existing preclinical animal models, including a tractable framework amenable to high-throughput assays and short relative lifespan conducive to lifelong mechanistic investigation. The use of flies also provides an opportunity to investigate important risk factors associated with neurodegenerative conditions, specifically age and sex. In this review, we survey current literature that examines age and sex as contributing factors to head trauma-mediated neurodegeneration in humans and preclinical models, including mammalian and Drosophila models. We discuss similarities and disparities between human and fly in aging, sex differences, and pathophysiology. Finally, we highlight Drosophila as an effective tool for investigating mechanisms underlying head trauma-induced neurodegeneration and for identifying therapeutic targets for treatment and recovery.

Sex differences in hippocampal-dependent memory and the hippocampal lipidome in adolescent rats raised on diets with or without DHA

Recent studies suggest the effects of DHA supplementation on human memory may differ between females and males during infancy, adolescence, and early adulthood, but the underlying mechanisms are not clear. As a result, this study sought to examine the spatial memory and brain lipidomic profiles in female and male adolescent rats with or without a DHA-enriched diet that began perinatally with the supplementation of dams. Spatial learning and memory were examined in adolescent rats using the Morris Water Maze beginning at 6 weeks of age and animals were sacrificed at 7 weeks of age to permit isolation of brain tissue and blood samples. Behavioral testing showed that there was a significant diet x sex interaction for two key measures of spatial memory (distance to zone and time spent in the correct quadrant during the probe test), with female rats benefiting the most from DHA supplementation. Lipidomic analyses suggest levels of arachidonic acid (ARA) and n-6 docosapentaenoic acid (DPA) containing phospholipid species were lower in the hippocampus of DHA supplemented compared with control animals, and principal component analyses revealed a potential dietary treatment effect for hippocampal PUFA. Females fed DHA had slightly more PE P-18:0_22:6 and maintained levels of PE 18:0_20:4 in the hippocampus in contrast with males fed DHA. Understanding how DHA supplementation during the perinatal and adolescent periods changes cognitive function in a sex-specific manner has important implications for determining the dietary requirements of DHA. This study adds to previous work highlighting the importance of DHA for spatial memory and provides evidence that further research needs to consider how DHA supplementation can cause sex-specific changes.

Association of telomere length and mitochondrial DNA copy number, two biomarkers of biological aging, with the risk of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is the third most common cardiovascular disease and occurs in all age groups, albeit the risk increases considerably with age. Previous research indicates mitochondrial dysfunction and telomere shortening in cardiovascular aging. However, in the context of VTE this has not been investigated in detail.

AIM

We aimed to explore biomarkers reflecting biological aging (i.e. human mitochondrial DNA copy number (mtDNA) and telomere length) and their association with VTE.

METHODS

mtDNA and telomere length were measured in a case-control study of 116 patients with a history of VTE and 128 age- and sex-matched healthy individuals from isolated blood using a qPCR-based assay kit. Cases had at least one unprovoked VTE event and were enrolled no earlier than 3 months after the last VTE event.

RESULTS

The mtDNA copy number was significantly lower in VTE cases compared to controls (median [IQR]: 663 per diploid cells [78.75-2204.5] vs. 2832 per diploid cells [724-4350]; p < 0.001). After adjustment for age, sex, BMI, and smoking, mtDNA copy number was independently associated with VTE risk (odds ratio per increase in 400 mtDNA per diploid cell: 0.889, 95%CI 0.834-0.947). mtDNA copy numbers were significantly different between women and men (2375 [455-3737] women vs. 893 [152-3154] men; p < 0.001). The analysis of telomere length showed no significant difference between patients and healthy controls.

CONCLUSION

Lower mtDNA levels were found in patients with VTE compared to controls, indicating an association of biological aging with risk of VTE.

Computational and mitochondrial functional studies of novel compound heterozygous variants in SPATA5 gene support a causal link with epileptogenic encephalopathy

The SPATA5 gene encodes a 892 amino-acids long protein that has a putative mitochondrial targeting sequence and has been proposed to function in maintenance of mitochondrial function and integrity during mouse spermatogenesis. Several studies have associated homozygous or compound heterozygous mutations in SPATA5 gene to microcephaly, intellectual disability, seizures and hearing loss. This suggests a role of the SPATA5 gene also in neuronal development. Recently, our group presented results validating the use of blood cells for the assessment of mitochondrial function for diagnosis and follow-up of mitochondrial disease, minimizing the need for invasive procedures such as muscle biopsy. In this study, we were able to diagnose a patient with epileptogenic encephalopathy using next generation sequencing. We found two novel compound heterozygous variants in SPATA5 that are most likely causative. To analyze the impact of SPATA5 mutations on mitochondrial functional studies directly on the patients' mononuclear cells and platelets were undertaken. Oxygen consumption rates in platelets and PBMCs were impaired in the patient when compared to a healthy control. Also, a decrease in mitochondrial mass was observed in the patient monocytes with respect to the control. This suggests a true pathogenic effect of the mutations in mitochondrial function, especially in energy production and possibly biogenesis, leading to the observed phenotype.

Systems level analysis of sex-dependent gene expression changes in Parkinson's disease

Parkinson's disease (PD) is a heterogeneous disorder, and among the factors which influence the symptom profile, biological sex has been reported to play a significant role. While males have a higher age-adjusted disease incidence and are more frequently affected by muscle rigidity, females present more often with disabling tremors. The molecular mechanisms involved in these differences are still largely unknown, and an improved understanding of the relevant factors may open new avenues for pharmacological disease modification. To help address this challenge, we conducted a meta-analysis of disease-associated molecular sex differences in brain transcriptomics data from case/control studies. Both sex-specific (alteration in only one sex) and sex-dimorphic changes (changes in both sexes, but with opposite direction) were identified. Using further systems level pathway and network analyses, coordinated sex-related alterations were studied. These analyses revealed significant disease-associated sex differences in mitochondrial pathways and highlight specific regulatory factors whose activity changes can explain downstream network alterations, propagated through gene regulatory cascades. Single-cell expression data analyses confirmed the main pathway-level changes observed in bulk transcriptomics data. Overall, our analyses revealed significant sex disparities in PD-associated transcriptomic changes, resulting in coordinated modulations of molecular processes. Among the regulatory factors involved, NR4A2 has already been reported to harbor rare mutations in familial PD and its pharmacological activation confers neuroprotective effects in toxin-induced models of Parkinsonism. Our observations suggest that NR4A2 may warrant further research as a potential adjuvant therapeutic target to address a subset of pathological molecular features of PD that display sex-associated profiles.

Porcine blood cell and brain tissue energy metabolism: Effects of "early life stress"

Background: Early Life Stress (ELS) may exert long-lasting biological effects, e.g., on PBMC energy metabolism and mitochondrial respiration. Data on its effect on brain tissue mitochondrial respiration is scarce, and it is unclear whether blood cell mitochondrial activity mirrors that of brain tissue. This study investigated blood immune cell and brain tissue mitochondrial respiratory activity in a porcine ELS model. Methods: This prospective randomized, controlled, animal investigation comprised 12 German Large White swine of either sex, which were weaned at PND (postnatal day) 28-35 (control) or PND21 (ELS). At 20-24 weeks, animals were anesthetized, mechanically ventilated and surgically instrumented. We determined serum hormone, cytokine, and "brain injury marker" levels, superoxide anion (O₂ ^•¯) formation and mitochondrial respiration in isolated immune cells and immediate post mortem frontal cortex brain tissue. Results: ELS animals presented with higher glucose levels, lower mean arterial pressure. Most determined serum factors did not differ. In male controls, TNFα and IL-10 levels were both higher than in female controls as well as, no matter the gender in ELS animals. MAP-2, GFAP, and NSE were also higher in male controls than in the other three groups. Neither PBMC routine respiration and brain tissue oxidative phosphorylation nor maximal electron transfer capacity in the uncoupled state (ETC) showed any difference between ELS and controls. There was no significant relation between brain tissue and PBMC, ETC, or brain tissue, ETC, and PBMC bioenergetic health index. Whole blood O₂ ^•¯ concentrations and PBMC O₂ ^•¯ production were comparable between groups. However, granulocyte O₂ ^•¯ production after stimulation with E. coli was lower in the ELS group, and this effect was sex-specific: increased O₂ ^•¯ production increased upon stimulation in all control animals, which was abolished in the female ELS swine. Conclusion: This study provides evidence that ELS i) may, gender-specifically, affect the immune response to general anesthesia as well as O₂ ^•¯ radical production at sexual maturity, ii) has limited effects on brain and peripheral blood immune cell mitochondrial respiratory activity, and iii) mitochondrial respiratory activity of peripheral blood immune cells and brain tissue do not correlate.

Sex-specific DNA methylation and associations with in utero tobacco smoke exposure at nuclear-encoded mitochondrial genes

Sex-linked differences in mitochondrial ATP production, enzyme activities, and reactive oxygen species generation have been reported in multiple tissue and cell types. While the effects of reproductive hormones underlie many of these differences, regulation of sexually dimorphic mitochondrial function has not been fully characterized. We hypothesized that sex-specific DNA methylation contributes to sex-specific expression of nuclear genes that influence mitochondrial function. Herein, we analysed DNA methylation data specifically focused on nuclear-encoded mitochondrial genes in 191 males and 190 females. We found 596 differentially methylated sites (DMSs) (FDR p < 0.05), corresponding to 324 genes, with at least a 1% difference in methylation between sexes. To investigate the potential functional significance, we utilized gene expression microarray data. Of the 324 genes containing DMSs, 17 showed differences in gene expression by sex. Particularly striking was that ATP5G2, encoding subunit C of ATP synthase, contains seven DMSs and exhibits a sex difference in expression (p = 0.04). Finally, we also found that alterations in DNA methylation associated with in utero tobacco smoke exposure were sex-specific in these nuclear-encoded mitochondrial genes. Interestingly, the level of sex differences in DNA methylation at nuclear-encoded mitochondrial genes and the level of methylation changes associated with smoke exposure were less prominent than that of other genes. This suggests more conservative regulation of DNA methylation at these nuclear-encoded mitochondrial genes as compared to others. Overall, our findings suggest that sex-specific DNA methylation may help establish sex differences in expression and function and that sex-specific alterations in DNA methylation in response to exposures could contribute to sex-variable toxicological responses.

Identification of mitochondrial genetic variants associated with human corneocyte size in Japanese women

Mitochondria have their own DNA (mtDNA). Genetic variants are likely to accumulate in mtDNA, and its base substitution rate is known to be very fast, 10-20 times faster than that of nuclear DNA. For this reason, mtSNPs (mitochondrial genome single nucleotide polymorphisms) are frequently detected in mtDNA. Several thousands of copies of mtDNA are considered to be present in a cell, and variants that have occurred in mtDNA are expected to markedly affect the intracellular energy production system and ROS (reactive oxygen species) kinetics. Therefore, recently, mtSNPs have come to be considered very important as a determinant of the individual constitution such as the life-span and disease susceptibility. In this study, we searched for mtSNPs that affect the individual corneocyte size using samples from 358 Japanese women. As a result, mtSNPs 10609C and 12406A were found to be significantly related to the corneocyte size in the outermost layer of the epidermis. There have been a large number of reports concerning the association between mtSNPs and individual constitution, but little evaluation of their relationships with epidermal properties has been made. The results of the present study first suggested that mtSNPs may affect the epidermal properties in Japanese women.

Autism: genetics, environmental stressors, maternal immune activation, and the male bias in autism

Autism spectrum disorder (ASD) is a class of neurodevelopmental disorders (NDD) characterized by deficits in three domains: impairments in social interactions, language, and communication, and increased stereotyped restrictive/repetitive behaviors and interests. The exact etiology of ASD remains unknown. Genetics, gestational exposure to inflammation, and environmental stressors, which combine to affect mitochondrial dysfunction and metabolism, are implicated yet poorly understood contributors and incompletely delineated pathways toward the relative risk of ASD. Many studies have shown a clear male bias in the incidence of ASD and other NDD. In other words, being male is a significant yet poorly understood risk factor for the development of NDD. This review discusses the link between these factors by looking at the current body of evidence. Understanding the link between the multiplicity of hits—from genes to environmental stressors and possible sexual determinants, contributing to autism susceptibility is critical to developing targeted interventions to mitigate these risks.

Integrative Profiling of Amyotrophic Lateral Sclerosis Lymphoblasts Identifies Unique Metabolic and Mitochondrial Disease Fingerprints

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease with a rapid progression and no effective treatment. Metabolic and mitochondrial alterations in peripheral tissues of ALS patients may present diagnostic and therapeutic interest. We aimed to identify mitochondrial fingerprints in lymphoblast from ALS patients harboring SOD1 mutations (mutSOD1) or with unidentified mutations (undSOD1), compared with age-/sex-matched controls. Three groups of lymphoblasts, from mutSOD1 or undSOD1 ALS patients and age-/sex-matched controls, were obtained from Coriell Biobank and divided into 3 age-/sex-matched cohorts. Mitochondria-associated metabolic pathways were analyzed using Seahorse MitoStress and ATP Rate assays, complemented with metabolic phenotype microarrays, metabolite levels, gene expression, and protein expression and activity. Pooled (all cohorts) and paired (intra-cohort) analyses were performed by using bioinformatic tools, and the features with higher information gain values were selected and used for principal component analysis and Naïve Bayes classification. Considering the group as a target, the features that contributed to better segregation of control, undSOD1, and mutSOD1 were found to be the protein levels of Tfam and glycolytic ATP production rate. Metabolic phenotypic profiles in lymphoblasts from ALS patients with mutSOD1 and undSOD1 revealed unique age-dependent different substrate oxidation profiles. For most parameters, different patterns of variation in experimental endpoints in lymphoblasts were found between cohorts, which may be due to the age or sex of the donor. In the present work, we investigated several metabolic and mitochondrial hallmarks in lymphoblasts from each donor, and although a high heterogeneity of results was found, we identified specific metabolic and mitochondrial fingerprints, especially protein levels of Tfam and glycolytic ATP production rate, that may have a diagnostic and therapeutic interest.

Sex bias in systemic lupus erythematosus: a molecular insight

Acknowledging sex differences in immune response is particularly important when we consider the differences between men and women in the incidence of disease. For example, over 80% of autoimmune disease occurs in women, whereas men have a higher incidence of solid tumors compared to women. In general women have stronger innate and adaptive immune responses than men, explaining their ability to clear viral and bacterial infections faster, but also contributing to their increased susceptibility to autoimmune disease. The autoimmune disease systemic lupus erythematosus (SLE) is the archetypical sexually dimorphic disease, with 90% of patients being women. Various mechanisms have been suggested to account for the female prevalence of SLE, including sex hormones, X-linked genes, and epigenetic regulation of gene expression. Here, we will discuss how these mechanisms contribute to pathobiology of SLE and how type I interferons work with them to augment sex specific disease pathogenesis in SLE.