Markers Of Mitochondrial Dysfunction Research Articles

High serum gamma-glutamyltransferase level after hepatitisC virus elimination is a risk factor for the development of hepatocellular carcinoma.

Gamma-glutamyltransferase (GGT) is known as an oxidative stress marker, induced by alcohol consumption and metabolic disorders, and is reported as a predictor of hepatocellular carcinoma (HCC) development after hepatitisC virus (HCV) elimination. However, it is not clear whether GGT serves simply as a surrogate marker for overlapping metabolic diseases or reflects HCV-specific carcinogenicity. We investigated the association between GGT and hepatocarcinogenesis after achieving a sustained viral response (SVR), accounting for drinking habits or diabetes, and examined predisposing factors associated with GGT levels after SVR. This is a prospective, multicenter, and observational study using the database of 1001 patients after HCV eradication with direct-acting antiviral agents. The association of GGT at SVR with cumulative HCC development was examined in a multivariate analysis using Cox proportional hazard models after adjustment for covariates including alcohol and diabetes. The association between oxidative stress markers or genetic factors and GGT levels was analyzed. High GGT levels at SVR were associated with HCC development (HR] 2.38, 95% CI 1.10-5.17). This association was also significant when restricted to patients without alcohol consumption or diabetes (HR 8.38, 95% CI 2.87-24.47). GGT levels were correlated with serum growth differentiation factor 15 levels, a marker of mitochondrial dysfunction. Single-nucleotide polymorphisms of ZNF827 and GDF15 were associated with high GGT levels. High GGT levels at SVR were associated with HCC development after accounting for alcohol consumption and diabetes. GGT levels are influenced by genetic predisposition and may reflect mitochondrial dysfunction after HCV eradication.

Influence of Fullerene–Ruboxyl Dyad on Markers of Mitochondrial Dysfunction In Vitro

Influence of Fullerene–Ruboxyl Dyad on Markers of Mitochondrial Dysfunction In Vitro

Ectopic expression of the mitochondrial protein COXFA4L3 in human sperm acrosome and its potential application in the selection of male infertility treatments.

Spermatogenesis requires a large amount of energy, which is primarily produced by the mitochondrial electron transfer chain. Mitochondrial dysfunction affects male infertility, suggesting a relationship between the electron transfer chain and male infertility. COXFA4L3 (C15ORF48) is an emerging subunit protein of cytochrome oxidase specifically expressed in germ cells during spermatogenesis, and it may be involved in male infertility. Therefore, to investigate whether COXFA4L3 could be a marker of mitochondrial dysfunction in the sperm, this study examined the protein expression and localization profile of COXFA4L3 in the sperm of male patients with infertility. Twenty-seven semen samples from a male infertility clinic at the Reproductive Center of Yokohama City University Medical Center were used to analyze sperm quality parameters and the expression and localization of energy production-related proteins. These data were compared with the outcomes of infertility treatment. The expression levels of COXFA4L3 varied significantly between samples. Furthermore, COXFA4L3 was ectopically localized to the acrosome. Ectopic expression of COXFA4L3 and PNA-stained acrosomes may be useful parameters for fertility treatment selection. Assessing the acrosomal localization of COXFA4L3 will expedite pregnancy treatment planning.

5-HT3 antagonist, tropisetron, ameliorates age-related renal injury induced by D-galactose in male mice: Up-regulation of sirtuin 1.

The kidney ages faster than other organs due to changes in energy metabolism, mitochondrial dysfunction, and oxidative stress. This study looked into the anti-aging effect of tropisetron. D-galactose was administrated subcutaneously in a mouse model for eight weeks in order to induce renal aging. Three separate intraperitoneal doses of tropisetron (1, 3, and 5 mg/kg body weight) were given at the same time. We assessed markers of mitochondrial dysfunction, oxidative stress, and inflammation. Via Real-Time PCR, the expressions of genes linked to aging (SIRT1) and apoptosis (Bax and Bcl-2) were ascertained. In addition, an assessment of histopathological changes, blood urea nitrogen, and creatinine concentrations was done. In kidney tissue, tropisetron reduces mitochondrial dysfunction and oxidative stress, which are caused by D-galactose-induced overproduction of inflammatory mediators. Additionally, tropisetron demonstrated antiapoptotic activity in renal tissue and augmented the decrease in SIRT1 gene expression associated with D-galactose administration. Besides, tropisetron significantly improved the histological alterations in the renal tissues of aged mice and effectively decreased the elevated levels of creatinine and also blood urea nitrogen. The results provided additional insight into the effect of tropisetron on renal aging and the underlying mechanisms, particularly through its ability to modulate SIRT1 signaling.

Mitochondrial DNA copy number in patients with systemic sclerosis.

Introduction: Systemic scleroderma (SSc) is a chronic autoimmune disease of inflammatory origin. Mitochondrial dysfunction is considered as an important mechanism in the pathogenesis of SSc. Currently mitochondrial DNA (mtDNA) copy number is used as a surrogate marker of mitochondrial dysfunction. Previous studies demonstrate that innate immune cells are important participants in inflammatory and fibrotic processes in SSc. The aim of the study was to evaluate the number of mtDNA copies in CD14+ monocytes and whole blood of patients with SSc in comparison with healthy individuals. Methods: Absolute mtDNA copy number was measured using digital PCR. It was found that the number of mtDNA copies in CD14+ monocytes was significantly higher in patients with SSc compared to control, while the number of mtDNA copies in the whole blood did not have significant differences. Results: The correlation analysis revealed an inverse association of mtDNA copy number with disease duration and the relationship between pro-inflammatory activation of CD14+ monocytes in terms of LPS-stimulated IL-6 secretion and mtDNA copy number. At the same time, basal and LPS-stimulated secretion of IL-6 by cultured CD+ monocytes were significantly higher in SSc group in comparison with control. Discussion: The study results suggest that increase of mtDNA copy number in CD14+ monocytes is a possible mechanism to maintain the reduced function of defective mitochondria in monocytes from patients with SSc associated with the development and progression of SSc.

Senescence and Mitochondrial Transfer Ability of Bone Marrow Mesenchymal Stromal Cells Influence Patterns of Alloreactivity after Allogeneic Hematopoietic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only curative treatment for acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). However post-transplant disease recurrence and alloreactive complications (chiefly graft versus host diseases - GvHD) are still associated with severe morbidity and mortality. Proliferative advantage of transformed cells as well as immune and microenvironmental dysregulations contribute both to promoting relapse and escape from graft versus leukemia (GvL) effect. Bone marrow (BM) mesenchymal stromal cells (MSC) are well known for their role in hematopoiesis and immune modulation. MSCs have been shown able to transfer mitochondria (MT) to different cell populations, including immune effectors, in order to (re)establish a healthy oxidative metabolism within the recipient cell. Here we hypothesize that these mechanisms are highly active in BM microenvironment after allo-HSCT and may contribute to alloreactivity, modifying the immune environment. On this basis we stipulate that those intercellular exchanges are deeply impacted by MSCs' senescence, that could be deployed as a useful parameter to predict post-transplant outcomes. To that end, we conducted a translational research, based on BM specimens prospectively collected at our Institution (NCT03357172, NCT03964922), involving patients undergoing allo-HSCT for high-risk MDS and AML and receiving fludarabine/busulfan-based conditioning regimens, anti-lymphoglobuline and cyclosporin/mycophenolate mofetil. MSC phenotype and functionality at the pre-transplant stage, MT capacity, immunomodulation towards T cells and phenotype were studied by multiparametric flow cytometry. Cell metabolism, in terms of oxygen consumption and extracellular acidification rate, was characterized with Seahorse XF technology. Percentages of senescent MSCs were determined with SA β-galactosidase test. First, we compared phenotypic and metabolic characteristics of MSC from MDS/AML (N=29) patients with those retrieved from a cohort of healthy controls (N=8). We observed that patient MSCs were characterized by higher expression of CD157 and CD146 and lower expression of CD200 as compared to healthy MSCs. Pre-transplant senescence quantification highlighted a certain degree of heterogeneity within the MSC compartment in leukemic patients (median = 37.42% sd=16.30 for AML patient and m=11.74% sd=6.4 for HC). In an attempt to link clinical phenotypes to this heterogeneity, we observed that patients with high degree of MSC senescence in pretransplant samples (mean= 51.6% sd=16.6 cells/sample), developed more frequently acute GvHD, as compared to those with low degree of pre-transplant MSC senescence (mean= 23.8% sd=14.3) who experienced instead a higher incidence of disease relapse (p=0,004). Assuming that the link between senescence and alloreactivity could rely to different metabolic states and MT capabilities in MSCs, we analyzed these biological features in our samples. Indeed, we observed that low degree of MSC senescence was associated with higher MT to T cells, in particular to CD4+ cells, shifting their metabolism and phenotype toward an immunosuppressive state The characterization of cellular metabolism showed in highly senescent MSCs the presence of markers of mitochondrial dysfunction with high oxidative power, but reduced coupling efficiency of respiratory chain. This metabolic profile involved a high mitochondrial mass characterized by a high maximal respiration capacity compared to HC MSCs. The in vitro modulation of MSC senescence with nicotinamide administration restored healthy mitochondrial metabolism and improved coupling efficacy of oxidative phosphorylation, possibly impacting on the immunomodulation capabilities of this microenvironment component. Here for the first time, we provide the evidence that MSC senescence plays an pivotal role in defining an altered immune state in transplanted AML possibly shifting the degree of alloreactivity from a high GvH/GvL response (high GvHD and low relapse) to a high immunosuppressive state (low GvHD and high relapse). These findings pave the way for implementing MSC senescence as a biomarker able to predict post-transplant outcomes and show new biological rationales to integrate donor-derived MSC products to better adjust GvH responses.

The NADase CD38 may not dictate NAD levels in brain mitochondria of aged mice but regulates hydrogen peroxide generation

Aging is a time-related functional decline that affects many species. One of the hallmarks of aging is mitochondrial dysfunction, which leads to metabolic decline. The NAD decline during aging, in several tissues, correlates with increase in NADase activity of CD38. Knock out or pharmacological inhibition of CD38 activity can rescue mitochondrial function in several tissues, however, the role of CD38 in controlling NAD levels and metabolic function in the aging brain is unknown. In this work, we investigated CD38 NADase activity controlling NAD levels and mitochondrial function in mice brain with aging. We demonstrate that NADase activity of CD38 does not dictate NAD total levels in brain of aging mice and does not control mitochondrial oxygen consumption nor other oxygen parameters markers of mitochondrial dysfunction. However, for the first time we show that CD38 regulates hydrogen peroxide (H2O2) generation, one of the reactive oxygen species (ROS) in aging brain, through regulation of pyruvate dehydrogenase and alfa-ketoglutarate dehydrogenase, as mitochondria H2O2 leakage sites. The effect may be related to mitochondrial calcium handling differences in CD38 absence. Our study highlights a novel role of CD38 in brain energy metabolism and aging.

Abstract P183: Porcupine Protects The Kidney By Suppressing Tubular Inflammation And Preserving Mitochondrial Integrity

Chronic Kidney Disease (CKD) progression may be slowed or stopped with early diagnosis and intervention, so developing novel therapies is paramount. The Wnt acyl transferase porcupine (PORCN) regulates the secretion of all 19 Wnt ligand isoforms that propagate β-catenin signaling. We find that mice with deletion of PORCN from kidney epithelia (PORCN iKKO) had augmented kidney injury in the nephrotoxic serum nephritis (NTS) model of CKD, with higher BUNs (202 ± 12 vs. 101 ± 38, mg/dL; p<0.01), and renal mRNA levels for NGAL (6.1±1.14 vs. 1.0±0.35 au, p=0.0013), KIM-1(2.5±0.65 vs. 1.0±0.26 au, p=0.046), collagen I (2.4±0.31 vs. 1.0±0.38 au, p=0.025), and fibronectin (2.5±0.35 vs. 1.0±0.27 au, p=0.006) compared to wild-type (WT) controls. PORCN iKKOs also had upregulated renal protein levels for collagen I (1.5 ± 0.2 vs. 1.0 ± 0.1 au; p=0.01) and fibronectin (1.8 ± 0.3 vs. 1.0 ± 0.1 au; p<0.01), recapitulating the mRNA patterns. We also detected marked TNFα mRNA upregulation in the PORCN iKKO kidneys vs WTs during CKD (2.6±0.67 vs. 1.0±0.30 au, p=0.036). TNFα is a potent driver of renal injury and fibrosis, acting via TNFα receptor 1(TNFR1) to promote ROS generation. At day 14 of NTS, PORCN iKKO kidneys contained higher levels of the ROS metabolite, 8-isoprostane (2348 ± 718 vs. 486 ± 77, pg/mg kidney; p=0.02), and expressed higher levels of mitochondrial dysfunction markers, including Drp1 (1.26 ± 0.06 vs. 1.0 ± 0.04 au; p<0.01) and p62 (1.3 ± 0.09 vs. 1.0 ± 0.07 au; p=0.07). TNFR1 inhibition (R-7050, 12mg/kg, IP, every other day) reduced BUNs (94.13 ± 3 vs. 90.26 ± 4.1, mg/dL; p=0.46) and renal Drp1 protein levels (1.4 ± 0.17 vs. 1.0 ± 0.15 au; p=0.11) in the PORCN iKKO cohort to WT levels. In primary renal tubular cells (RTCs), TNFα treatment (50ng/ml, 12hrs) induced 8-isoprostane generation (387 ± 119 vs. 121 ± 39, pg/ml in medium; p=0.07), corroborating our in vivo studies. Moreover, treatment of the RTCs with the Drp1 inhibitor mdivi-1 (MD1, 10μm) for 12 hours attenuated TNFα-induced accumulation of fibronectin and collagen I. Our studies suggest that PORCN in renal epithelia protects against kidney damage by limiting TNFα induction, thereby diminishing Drp1-mediated mitochondrial dysfunction and ROS generation.

TDP-43 is a potential marker of dopaminergic neuronal damage caused by atrazine exposure

Atrazine (ATR) is one of the herbicides widely used worldwide. Meanwhile, it is an environmental endocrine disruptor that can cross the blood-brain barrier and cause damage to the endocrine-nervous system, especially by affecting the normal secretion of dopamine (DA). Regrettably, effector markers and cascade response mechanisms in damaged dopaminergic neurons induced by ATR exposure remain elusive. In this paper, we focus on investigating aggregation and position change of transactive response DNA-binding protein-43 (TDP-43) after ATR exposure, and illustrating whether TDP-43 can serve as a potential marker of mitochondrial dysfunction which causes damage to dopaminergic neurons. In our study, we used rat adrenal pheochromocytoma cell line 12 (PC12) to establish an in vitro model of dopaminergic neurons. After PC12 was intervened by ATR, we found reduced DA cycling and DA levels, and that TDP-43 aggregated continuously in the cytoplasm and then translocated to mitochondria. Furthermore, the studies we have performed showed that the translocation can cause mitochondrial dysfunction through activating the unfolded mitochondrial protein response (UPRmt), ultimately causing damage to dopaminergic neuron. The research we have done suggests that TDP-43 can serve as a potential effector marker of dopaminergic neuron damaged caused by ATR exposure.

Neuroinflammation, Energy and Sphingolipid Metabolism Biomarkers Are Revealed by Metabolic Modeling of Autistic Brains

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders generally characterized by repetitive behaviors and difficulties in communication and social behavior. Despite its heterogeneous nature, several metabolic dysregulations are prevalent in individuals with ASD. This work aims to understand ASD brain metabolism by constructing an ASD-specific prefrontal cortex genome-scale metabolic model (GEM) using transcriptomics data to decipher novel neuroinflammatory biomarkers. The healthy and ASD-specific models are compared via uniform sampling to identify ASD-exclusive metabolic features. Noticeably, the results of our simulations and those found in the literature are comparable, supporting the accuracy of our reconstructed ASD model. We identified that several oxidative stress, mitochondrial dysfunction, and inflammatory markers are elevated in ASD. While oxidative phosphorylation fluxes were similar for healthy and ASD-specific models, and the fluxes through the pathway were nearly undisturbed, the tricarboxylic acid (TCA) fluxes indicated disruptions in the pathway. Similarly, the secretions of mitochondrial dysfunction markers such as pyruvate are found to be higher, as well as the activities of oxidative stress marker enzymes like alanine and aspartate aminotransferases (ALT and AST) and glutathione-disulfide reductase (GSR). We also detected abnormalities in the sphingolipid metabolism, which has been implicated in many inflammatory and immune processes, but its relationship with ASD has not been thoroughly explored in the existing literature. We suggest that important sphingolipid metabolites, such as sphingosine-1-phosphate (S1P), ceramide, and glucosylceramide, may be promising biomarkers for the diagnosis of ASD and provide an opportunity for the adoption of early intervention for young children.

Abstract TP235: Temporal Change Of Brain Mitochondrial Function In A Rodent Model Of Subarachnoid Hemorrhage

Introduction: Subarachnoid hemorrhage (SAH) is a devastating disease. A third of the patients die and a large percentage of the survivors require support in daily living and suffers from reduced quality of life. As part of clinical practice for these patients, a cerebral microdialysis catheter may be placed to monitor cerebral metabolic function. Using this monitoring technique, the patients often demonstrate an increase in the lactate-pyruvate ratio, despite adequate supply of glucose and oxygen, which may be an indirect marker of mitochondrial dysfunction. We wanted to identify a possible mitochondrial dysfunction in a rat SAH model at different time points by directly measuring mitochondrial function in brain tissue ex vivo . Method: The pre-chiasmatic single injection model of SAH was used. Oroboros Oxygraph high resolution respirometry was used to evaluate the electron transport chain of the mitochondria. We also analyzed ROS generation simultaneously at the same time points using the Oroboros LED2 module. We measured tissue from the cortex and the hippocampus. Results: 45 rats at four different timepoints, 6-, 24-, 48- and 96 hours after surgery, were included. We identified a significant reduction in respiration through complexes I and II of the electron transport chain in hippocampal tissue at 96 hours after SAH compared to sham. The respiration of cortical tissue at the same time point was reduced compared to sham but did not reach significance. No differences were identified at other time points and no differences in ROS generation were identified. Conclusion: We conclude that the SAH model can be used as a suitable model to identify mitochondrial dysfunction and that the respiratory capacity of the electron transport chain is reduced in the hippocampus at 96 h post insult in this rat model of SAH.

Novel insights into the synergistic effects of selenium nanoparticles and metformin treatment of letrozole - induced polycystic ovarian syndrome: targeting PI3K/Akt signalling pathway, redox status and mitochondrial dysfunction in ovarian tissue

ABSTRACTPurposePolycystic ovary syndrome (PCOS) has a series of reproductive and metabolic consequences. Although the link between PCOS, IR, and obesity, their impact on the pathogenesis of PCOS has yet to be determined. Dysfunction of PI3K/AKT pathway has been reported as the main cause of IR in PCOS. This study purposed to explore the effects of selenium nanoparticles (SeNPs) alone and combined with metformin (MET) in a PCOS-IR rat model.MethodsAfter 3 weeks of treatment with SeNPs and/or MET, biochemical analysis of glycemic & lipid profiles, and serum reproductive hormones was performed. Inflammatory, oxidative stress, and mitochondrial dysfunction markers were determined colormetrically. The expression of PI3K and Akt genes were evaluated by Real-time PCR. Histopathological examination and Immunohistochemical analysis of Ki-67 expression were performed.ResultsThe results showed that treatment with SeNPs and/or MET significantly attenuated insulin sensitivity, lipid profile, sex hormones levels, inflammatory, oxidative stress and mitochondrial functions markers. Additionally, PI3K and Akt genes expression were significantly upregulated with improved ovarian histopathological changes.ConclusionCombined SeNPs and MET therapy could be potential therapeutic agent for PCOS-IR model via modulation of the PI3K/Akt pathway, enhancing anti-inflammatory and anti-oxidant properties and altered mitochondrial functions.HighlightsThe strong relationship between obesity, insulin resistance, and polycystic ovarian syndrome.Disturbance of the PI3K/Akt signaling pathway is involved in the progression of polycystic ovary syndrome-insulin resistance (PCOS-IR).In PCOS-IR rats, combined SeNPs and metformin therapy considerably alleviated IR by acting on the PI3K/Akt signaling pathway.The combination of SeNPs and metformin clearly repaired ovarian polycystic pathogenesis and improved hormonal imbalance in PCOS-IR rats.

Prognostic significance of cumulus cells mitochondrial dysfunction markers in obtaining optimal quality embryos in assisted reproductive technologies protocols

Prognostic significance of cumulus cells mitochondrial dysfunction markers in obtaining optimal quality embryos in assisted reproductive technologies protocols

The evaluation of S-(2-succinyl)cysteine, a marker for mitochondrial dysfunction, in chronic kidney disease

The evaluation of S-(2-succinyl)cysteine, a marker for mitochondrial dysfunction, in chronic kidney disease

Myocardial inflammation in ischaemic and non-ischaemic heart failure relates to impaired mitochondria

Abstract Background Mitochondrial dysfunction is a driving factor in the development of heart failure (HF) and relates to poor cardiac function. Through elevated oxidative stress it is linked to myocardial inflammation. Both mechanisms promote the development of cardiac fibrosis, a key contributor to adverse outcomes in ischaemic and non-ischaemic HF. Differences in myocardial mitochondrial function and inflammation between patients with ischaemic and non-ischaemic HF have been indicated. While immunosuppression in non-ischaemic HF with myocardial inflammation has improved long-term results, little is known about possible benefits in ischaemic HF. Purpose We hypothesised that: 1. Myocardial lymphocytic inflammation and fibrosis differ in patients with HF due to ischaemic cardiomyopathy (ICM) compared to patients with dilated cardiomyopathy (DCM). 2. Inflammation and fibrosis are associated with markers of mitochondrial dysfunction. Methods Myocardial tissue specimens were obtained from the left ventricular (LV) apex of 65 patients (n[ICM] = 33, n[DCM] = 32) with HF requiring an LV assist device or heart transplantation. We assessed oxidative phosphorylation capacity (OXPHOS) via high resolution respirometry in saponine-permeabilised myocardial fibres (OROBOROS Oxygraph-2k). Reactive oxygen species (ROS) production was measured fluoroscopically via the Amplex Red method. Immunohistochemistry staining for CD3 was performed on snap-frozen tissue and digitally analysed. Azan staining was used for quantification of fibrotic area. Statistical analysis was conducted with GraphPad Prism v9.0 and IBM SPSS v27.0. Results ICM and DCM patients did not differ significantly regarding age (60.9±5.4 vs. 55.8±12.4 years, p=0.11), sex (91% vs. 90% male, p=0.93), BMI (27.6±5.1 vs. 26.5±6.0 kg/m2, p=0.82), or diabetic status (31% vs. 20% Type 2 Diabetes mellitus, p=0.31). Tissue specimens of ICM patients displayed about three times larger fibrotic areas compared to DCM (20.9±21.2 vs. 7.2±5.6%, p=0.001). Cellular inflammation (>14 CD3+ cells/mm2) was significantly more common in ICM than DCM patients. (27 vs. 6%, p=0.024). Inflammation and fibrosis did not correlate significantly (r=0.09, p=0.46). Fibrosis was not associated with OXPHOS capacity (r=−0.129, p=0.33). In patients with inflammation, OXPHOS capacity was lower compared to patients without inflammation (92.3±40.1 vs. 131.6±55.6 pmol/(s*mg), p=0.031) and inflammation was associated with lower OXPHOS capacity (r=−0.296, p=0.019). There was a trend towards lower electron transfer capacity in patients with inflammation (98.6±43.1 vs. 129.7±48.3 pmol/(s*mg), p=0.053). ROS production was not significantly different between tissue specimens with or without inflammation (0.51±0.21 vs. 0.67±0.33 pmol/(s*ml), p=0.17). Conclusions Myocardial cellular inflammation is prominent in ICM patients and relates to impaired mitochondria. Future studies may evaluate possible benefits from immunosuppression in ICM patients. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Research Foundation (DFG)

Abstract 008: Genetic Studies Identify A Novel Role Of CCDC93 In Arterial Relaxation And Central Systolic Blood Pressure

Previous genome-wide association studies (GWAS) have identified and validated variants at more than 1000 loci with modest effects on population blood pressure (BP), explaining in aggregate ~6% of the trait variance and highlighting genetic differences in BP regulation in ethnically diverse populations. We performed an exome-wide association study (EWAS) in Han Chinese population (N=5,954) from Beijing and identified 4 EWAS single nucleotide polymorphism (SNP)-trait associations with 3 SNPs, including two novel associations (rs2165468-peripheral systolic BP and rs33975708-central systolic BP (cSBP). rs33975708 is a coding variant in the coiled-coil domain containing 93 ( CCDC93 ) gene, c.535C>T, p.Arg179Cys (MAF=0.15%) and was associated with substantially increased cSBP (β=29.3 mmHg, P =1.23E-7) in Han Chinese population. CRISPR/Cas9 was used to introduce this variant in mice to investigate vascular molecular mechanisms. While this did not yield a viable mouse with the specific SNP, we did generate mice with an out of frame deletion making a gene knock-out. Ccdc93 deletion ( Ccdc93 -/- ) in its homozygous form was embryonic lethal (<E10.5). Ccdc93 +/- heterozygous mice were viable and morphologically normal and displayed 1.31-fold lower aortic Ccdc93 protein expression (P=0.0041, N=6). Systolic BP was higher in Ccdc93 +/- mice (110±8 mmHg vs 125±10 mmHg, P=0.016, N=5-7) and showed impaired acetylcholine (Ach)-induced relaxation (max Ach 86% vs 68%, P<0.03) and enhanced phenylephrine (PE)-induced contraction (max PE 123% vs 198% normalized to KCL response, P<0.03, N=5) in thoracic aorta ex vivo . Transcriptome analysis by RNA-seq of thoracic aorta identified significantly enriched biological processes in Ccdc93 +/- among the pathways altered in fatty acid metabolic process (adjusted P=2.9E-9) together with mitochondrial metabolism (P=1.3E-14). Plasma free fatty acid levels were higher in Ccdc93 +/- mice (96±7 μM vs 124±13 μM, P=0.0031, N=6) and aortic parkin protein expression, a marker of mitochondrial dysfunction, was 1.63-fold higher (P=0.028, N=6). In conclusion, our genetic and functional studies indicate a potential novel role of CCDC93 on blood pressure regulation through its effects on vascular mitochondrial function.

Glucose- and Non-Glucose-Induced Mitochondrial Dysfunction in Diabetic Kidney Disease.

Mitochondrial dysfunction plays an important role in the pathogenesis and progression of diabetic kidney disease (DKD). In this review, we will discuss mitochondrial dysfunction observed in preclinical models of DKD as well as in clinical DKD with a focus on oxidative phosphorylation (OXPHOS), mitochondrial reactive oxygen species (mtROS), biogenesis, fission and fusion, mitophagy and urinary mitochondrial biomarkers. Both glucose- and non-glucose-induced mitochondrial dysfunction will be discussed. In terms of glucose-induced mitochondrial dysfunction, the energetic shift from OXPHOS to aerobic glycolysis, called the Warburg effect, occurs and the resulting toxic intermediates of glucose metabolism contribute to DKD-induced injury. In terms of non-glucose-induced mitochondrial dysfunction, we will review the roles of lipotoxicity, hypoxia and vasoactive pathways, including endothelin-1 (Edn1)/Edn1 receptor type A signaling pathways. Although the relative contribution of each of these pathways to DKD remains unclear, the goal of this review is to highlight the complexity of mitochondrial dysfunction in DKD and to discuss how markers of mitochondrial dysfunction could help us stratify patients at risk for DKD.

Mitochondrial Dysfunction in Primary Open-Angle Glaucoma Characterized by Flavoprotein Fluorescence at the Optic Nerve Head

To investigate the presence of flavoprotein fluorescence (FPF) at the optic nerve head (ONH) rim as a marker of mitochondrial dysfunction in primary open-angle glaucoma (POAG) and control eyes. Retrospective cross-sectional study of patients recruited from the New York Eye and Ear Infirmary of Mount Sinai. A total of 86 eyes (50 eyes of 30 patients with POAG and 36 eyes of 20 control participants) were enrolled. The presence of POAG was defined by circumpapillary retinal nerve fiber layer thickness (cpRNFLT) of less than the bottom fifth percentile of the normative database, glaucomatous ONH changes, and visual field defects on 24-2 tests. Primary open-angle glaucoma and control eyes were imaged using the OcuMet Beacon. A 23°× 23° infrared scan was obtained, and an FPF scan was performed within a capture field spanning 13° in diameter. The ONH margins on the infrared image were identified by software algorithms. Then, FPF was measured within an elliptical annulus around the ONH rim, with the inner and outer boundaries corresponding to 0.5 to 1.1 times the ONH rim size. Flavoprotein fluorescence at the OHN rim in POAG and control eyes. Differences in FPF between POAG and control eyes were characterized through mixed-effects logistic regression, adjusted for age and interocular pressure. Flavoprotein fluorescence was significantly higher in POAG versus control eyes, with a mean ± SD of 46.4 ± 27.9 versus 28.0 ± 11.7 (P < 0.001), respectively. Among POAG eyes, FPF showed correlation to visual field mean deviation (P < 0.001), visual field pattern standard deviation (P= 0.003), and cpRNFLT (P= 0.001) on linear mixed-effects models. Higher FPF in POAG versus control eyes suggests the presence of mitochondrial dysfunction at the ONH rim in eyes with glaucomatous damage. The degree of FPF corresponds to disease severity, as measured by visual field and nerve fiber layer thickness metrics. Thus, FPF may represent a metabolic indicator of disease status that reveals the extent of injury in glaucoma.

Interactions Between Plasma Amyloid and Aging Markers to Determine Clinically Meaningful Cognitive Decline

Background: Brain amyloidosis is a well-known pathological hallmark of Alzheimer’s disease (AD) and can be early identified by measuring plasma amyloid-β (Aβ) status. Growing evidence implicates the biological mechanisms of aging, including chronic inflammation, mitochondrial dysfunction and neurodegeneration, in AD pathogenesis. This study aims to investigate the interactions between plasma Aβ status and aging markers on clinically meaningful cognitive decline. Methods: This secondary analysis from Multidomain Alzheimer Preventive Trial (MAPT) enrolled 401 community-dwelling older adults (mean age ± SD: 76.7 ± 4.6 years) who had clinical dementia rating (CDR) scale as 0 or 0.5, and who had their plasma biomarkers measured: amyloidosis: Aβ42/40 ratio; inflammatory: tumor necrosis factor receptor type 1 (TNFR-1), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), C-reactive protein (CRP); mitochondrial dysfunction: growth differentiation factor 15 (GDF-15); neurodegeneration: neurofilament light chain (NfL). Cognitive decline was determined by diagnosed dementia and worsening CDR status. Cox regression and moderation modeling were applied to examine the interrelationships between biomarkers and risk of cognitive decline. Results: Among 401 participants, 43.9% were cognitive normal (CDR=0) and 56.1% were mild cognitive impairment (CDR=0.5) initially. After 3.3 ± 1.1 years of follow-up, 7.0% of population evolved dementia and 34.2% had worsening CDR status. GDF-15 and NfL presented prospective associations with incident dementia. However, risk of dementia associated with plasma Aβ did not change after considering the serum level of GDF-15 and NfL. Conclusion: The markers of mitochondrial dysfunction and neurodegeneration did not partially explain the associations between plasma Aβ status and cognitive decline in older adults.

Interactions Between Plasma Amyloid and Aging Markers to Determine Clinically Meaningful Cognitive Decline

Older adults’ experiences with memory problems may be an important indicator of current and future well-being; however, these experiences and their impacts are poorly characterized, particularly in those with co-occurring affective symptoms. The purpose of this mixed-methods study was to examine how the experience of memory problems influences emotional well-being in older adults without dementia, and whether this differs based on cognitive status and current depressive symptoms or anxiety symptoms. A convergent parallel mixed methods design was used in which quantitative and qualitative data were collected simultaneously, analyzed separately, and then integrated to determine how participants’ experiences differed. Community-dwelling older adults (n=49, Mage = 74.5, 63% female) without severe cognitive impairment completed study questionnaires and two individual, semi-structured interviews. Five themes were identified that described the influence of memory problems on emotional well-being: Evoking Emotions, Fearing Future, Undermining Self, Normalizing Problems, and Adjusting Thinking. The extent to which memory problems impacted emotional well-being depended on multiple factors including current affective symptoms (primarily anxiety), characteristics of the experience (such as judgments of its importance), as well as personal experience with dementia. Notably, there were no thematic differences in the emotional impact of memory problems between older adults with normal cognition and those with evidence of mild cognitive impairment. Our findings suggest that thorough assessment of reports of memory problems, regardless of cognitive testing outcomes, should consider co-occurring subsyndromal affective disorders as well as older adults’ evaluations of how memory problems influence their daily lives and well-being.