FGFR1 governs iron homeostasis via regulating intracellular protein degradation pathways of IRP2 in prostate cancer cells.

The acquisition of ectopic fibroblast growth factor receptor 1 (FGFR1) expression is well documented in prostate cancer (PCa) progression, notably in conferring tumor growth advantage and facilitating metastasis. However, how FGFR1 contributes to PCa progression is not fully revealed. Here we report that ectopic FGFR1 in PCa cells promotes transferrin receptor 1 (TFR1) expression and expands the labile iron pool (LIP), and vice versa. We further demonstrate that FGFR1 stabilizes iron regulatory proteins 2 (IRP2) and therefore, upregulates TFR1 via promoting IRP2 binding to the IRE of TFR1. Deletion of FGFR1 in DU145 cells decreases the LIP, which potentiates the anticancer efficacy of iron chelator. Intriguingly, forced expression of IRP2 in FGFR1 depleted cells reinstates TFR1 expression and LIP, subsequently restoring the tumorigenicity of the cells. Together, our results here unravel a new mechanism by which FGFR1 drives PCa progression and suggest a potential novel target for PCa therapy.

Excited-State Symmetry Breaking and Localization in a Noncentrosymmetric Electron Donor-Acceptor-Donor Molecule.

Electronic excitation in quadrupolar conjugated molecules rapidly localizes on a single electron donor-acceptor (DA) branch when in polar environments. The loss of center of inversion upon this excited-state symmetry breaking (ES-SB) can be monitored by exploiting the relaxation of the exclusion rules for IR and Raman vibrational transitions. Here, we compare ES-SB in a right-angled (1) and a centrosymmetric (2) DAD dyes using time-resolved IR spectroscopy. We show that the localization of the excitation can also be identified with the bent molecule 1. We find that contrary to dye 2, subpopulations with localized and delocalized excitation coexist for 1 in weak to medium polar solvents. This difference originates from the torsional disorder present in the excited state of 1 but not of 2. Additionally, irreversible localization in a bent molecule is shown to require higher solvent polarity than in a centrosymmetric one.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomes Alleviate Nuclear Pulposus Cells Degeneration Through the miR-145a-5p/USP31/HIF-1α Signaling Pathway.

Bone marrow mesenchymal stem cell (BMSC)-derived exosomes possess therapeutic potential against degenerative diseases. This study aimed to investigate the effects of BMSC-derived exosomes on intervertebral disc degeneration (IVDD) and explore the underlying molecular mechanisms. Through transcriptome sequencing and histological analysis, we observed a significant increase in HIF-1α expression in degenerative nucleus pulposus (NP) tissues. The addition of HIF-1α resulted in elevated expression of inflammatory factors IL-1ß and IL-6, higher levels of matrix-degrading enzyme MMP13, and lower expression of aggrecan in NP cells. Co-culturing with BMSCs diminished the expression of HIF-1α, MMP13, IL-1ß, and IL-6 in degenerative NP cells induced by overload pressure. miRNA chip analysis and PCR validation revealed that miR-145a-5p was the primary miRNA carried by BMSC-derived exosomes. Overexpression of miR-145a-5p was effective in minimizing the expression of HIF-1α, MMP13, IL-1ß, and IL-6 in degenerative NP cells. Luciferase reporter assays confirmed USP31 as the target gene of miR-145a-5p, and the regulation of NP cells by BMSC-derived exosomes via miR-145a-5p was dependent on USP31. In conclusion, BMSC-derived exosomes alleviated IVDD through the miR-145a-5p/USP31/HIF-1α signaling pathway, providing valuable insights into the treatment of IVDD.

FOXO-regulated OSER1 reduces oxidative stress and extends lifespan in multiple species.

FOXO transcription factors modulate aging-related pathways and influence longevity in multiple species, but the transcriptional targets that mediate these effects remain largely unknown. Here, we identify an evolutionarily conserved FOXO target gene, Oxidative stress-responsive serine-rich protein 1 (OSER1), whose overexpression extends lifespan in silkworms, nematodes, and flies, while its depletion correspondingly shortens lifespan. In flies, overexpression of OSER1 increases resistance to oxidative stress, starvation, and heat shock, while OSER1-depleted flies are more vulnerable to these stressors. In silkworms, hydrogen peroxide both induces and is scavenged by OSER1 in vitro and in vivo. Knockdown of OSER1 in Caenorhabditis elegans leads to increased ROS production and shorter lifespan, mitochondrial fragmentation, decreased ATP production, and altered transcription of mitochondrial genes. Human proteomic analysis suggests that OSER1 plays roles in oxidative stress response, cellular senescence, and reproduction, which is consistent with the data and suggests that OSER1 could play a role in fertility in silkworms and nematodes. Human studies demonstrate that polymorphic variants in OSER1 are associated with human longevity. In summary, OSER1 is an evolutionarily conserved FOXO-regulated protein that improves resistance to oxidative stress, maintains mitochondrial functional integrity, and increases lifespan in multiple species. Additional studies will clarify the role of OSER1 as a critical effector of healthy aging.

Effectiveness of Sodium-Glucose Cotransporter 2 Inhibitors in Patients With Acute Myocardial Infarction With or Without Type 2 Diabetes: A Systematic Review and Meta-analysis.

ABSTRACT: Recent studies have revealed the benefits of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in heart failure patients. However, their effects on acute myocardial infarction (AMI) remain uncertain. Therefore, we conducted this meta-analysis to assess the effectiveness of SGLT2i in patients with AMI with or without diabetes. We conducted a comprehensive search of PubMed, Embase, and Cochrane Library encompassing data from inception until November 30, 2023. Relevant studies comparing SGLT2i with placebo or non-SGLT2i in patients with AMI were included. The mean difference and/or odds ratio (OR) with 95% confidence intervals were pooled using a fixed-effects model when the heterogeneity statistic (I2) was less than 50%; otherwise, a random-effects model was employed. Four randomized controlled trials and 4 observational studies involving 9397 patients with AMI were included in this meta-analysis. Patients treated with SGLT2i exhibited a significantly lower rate of hospitalization for heart failure (OR = 0.50, 95% CI: 0.32-0.80) and all-cause death (OR = 0.65, 95% CI: 0.44-0.95) compared with those treated with placebo or non-SGLT2i. Furthermore, the use of SGLT2i was associated with a significant increase in left ventricular ejection fraction (mean difference = 1.90, 95% CI: 1.62-2.17) and a greater reduction of N-terminal prohormone of brain natriuretic peptide (OR = 0.88, 95% CI 0.82-0.94). Subgroup analysis revealed that in patients with diabetes, SGLT2i exhibited similar effects. The present meta-analysis provided evidence indicating the effectiveness of SGLT2i in patients with AMI; SGLT2i may serve as an additional therapeutic option for patients with AMI, regardless of the presence or absence of diabetes.

Effectiveness of sodium-glucose co-transporter 2 inhibitors on atrial fibrillation recurrence after catheter ablation: A systemic review and meta-analysis.

BACKGROUND: Studies have revealed the beneficial effects of sodium-glucose co-transporter 2 inhibitors (SGLT2i) for the treatment of heart failure (HF) regardless of the presence of diabetes. Besides, SGLT2i can decrease the incidence of atrial fibrillation (AF) in a broad population. However, the effects of SGLT2i on AF recurrence following catheter ablation (CA) remain uncertain. Therefore, this meta-analysis was undertaken to elucidate the effects of SGLT2i on AF recurrence after CA in AF patients. METHODS: A comprehensive search of PubMed, Embase, and Cochrane library was conducted for relevant studies, encompassing data from inception until March 20, 2024. The data were pooled using a fixed-effects model if the I2 value was <50%; otherwise, a random-effects model was adopted. RESULTS: One randomized controlled trial (RCT) and five observational studies involving 5623 patients with AF who underwent CA were included. SGLT2i treatment was associated with a significantly lower rate of AF recurrence (odds ratio [OR] = 0.45, 95% confidence interval [CI]: 0.31-0.66). Subgroup analysis demonstrated that patients treated with SGLT2i exhibited a lower incidence of AF recurrence compared to those treated with dipeptidyl peptidase-4 inhibitors (DPP4i). The favorable effects of SGLT2i on AF recurrence were more pronounced in male patients and patients with persistent AF. CONCLUSIONS: This meta-analysis provided evidence supporting the effectiveness of SGLT2i in reducing the risk of AF recurrence after CA in AF patients. SGLT2i may serve as an additional therapy option in this population.

Human fibroblasts from sporadic Alzheimer's disease (AD) patients show mitochondrial alterations and lysosome dysfunction.

Mitophagy is a mechanism that maintains mitochondrial integrity and homeostasis and is thought to promote longevity and reduce the risk of age-related neurodegenerative diseases, including Alzheimer's disease (AD). Here, we investigate the abundance of mitochondrial reactive oxygen species (ROS), mitochondrial function, and mitophagy in primary fibroblasts from patients with sporadic AD (sAD) and normal healthy controls. The results show increased levels of mitochondrial ROS, changes in mitochondrial morphology, altered bioenergetic properties, and defects in autophagy, mitophagy, and lysosome-mediated degradation pathways in sAD fibroblasts relative to control fibroblasts. Interestingly, lysosome abundance and the staining of lysosomal markers remained high, while the capacity of lysosome-dependent degradation was lower in sAD fibroblasts than in controls fibroblasts. Nicotinamide riboside supplementation decreased mitochondrial ROS, while capacity for lysosomal degradation remained unchanged in sAD fibroblasts relative to healthy control fibroblasts. These findings provide insight into molecular mechanisms involving the dysregulation of lysosome and autophagy/mitophagy pathways that may contribute significantly to clinical signs and pathological features of sAD.

Continued stepped care model improves early-stage self-report quality of life and knee function after total knee arthroplasty.

BACKGROUND: The Stepped Care Model (SCM) is an evidence-based treatment approach that tailors treatment intensity based on patients' health status, aiming to achieve the most positive treatment outcomes with the least intensive and cost-effective interventions. Currently, the effectiveness of the Stepped Care Model in postoperative rehabilitation for TKA (Total Knee Arthroplasty) patients has not been reported. OBJECTIVE: The present study aimed to investigate whether the stepped care model could improve early-stage self-report quality of life and knee function after total knee arthroplasty via a prospective randomized controlled design. METHODS: It was a mono-center, parallel-group, open-label, prospective randomized controlled study. Patients who aging from 60-75 years old as well as underwent unilateral primary total knee arthroplasty due to end-stage knee osteoarthritis between 2020.06 to 2022.02 were enrolled. Participants were randomized and arranged into two groups in a 1:1 allocation. The control group was given traditional rehabilitation guidance, while the stepped care model group was given continued stepped care. Hospital for special surgery knee score, daily living ability (ADL), knee flexion range, and adverse events at 1, 3, and 6 months after total knee arthroplasty were recorded. RESULTS: 88 patients proceeded to the final analysis. There was no significant difference of age, gender, length of stay, BMI, and educational level between the two groups at the baseline. After specific stepped care model interventions, patients showed significant improvements in HHS in 1 month (85.00 (82.25, 86.00) vs. 80.00 (75.00, 83.00), p< 0.001), 3 months (88.00 (86.00, 92.00) vs. 83.00 (76.75, 85.00), p< 0.001), and 6 months (93.00 (90.25, 98.00) vs. 88.00 (84.25, 91.75), p< 0.001) when compared with the control group. Similar results were also found in both daily living ability and knee flexion angle measurements. No adverse event was observed during the follow-up. CONCLUSION: The present study found that the stepped care model intervention significantly improved early-stage knee function and self-reported life quality after total knee arthroplasty due to knee osteoarthritis. Female patients and those less than 70 years old benefit more from the stepped care model intervention after total knee arthroplasty.

Epirubicin induces cardiotoxicity through disrupting ATP6V0A2-dependent lysosomal acidification and triggering ferroptosis in cardiomyocytes.

Epirubicin (EPI) is effective in the treatment of malignant cancers, but its application is limited by life-threatening cardiotoxicity. Iron homeostasis disturbance has been implicated in anthracycline induced cardiotoxicity (AIC), and ferroptosis is involved in AIC which dependent upon intracellular iron. However, the role and exact mechanisms of ferroptosis in the pathogenesis of epirubicin-induced cardiotoxicity (EIC) remain elusive. In this study, we aimed to investigate mechanisms underlying ferroptosis-driven EIC. Epirubicin triggered ferroptosis both in vivo and in cultured cardiomyocytes, and pretreatment with ferroptosis inhibitor, Ferrostatin-1(Fer-1) alleviates EIC. Microarray analysis was performed to screen for potential molecules involved in EIC in neonatal primary mouse ventricular cardiomyocytes (NMVMs). We found that the transcript level of ATP6V0A2, a subunit of vacuolar ATPase (V-ATPase), was significantly downregulated when NMVMs were subjected to EPI, which was verified in vivo and in vitro as measured by real time quantitative reverse transcription PCR (qRT-PCR) and immunoblotting. Intriguingly, overexpression of ATP6V0A2 effectively decreased excessive oxidative stress and lipid-peroxidation accumulation, thereby inhibiting ferroptosis and protecting cardiomyocytes against EIC, as evidenced by functional, enzymatic, and morphological changes. Mechanistically, forced expression of ATP6V0A2 restored lysosomal acidification in EPI-treated cardiomyocytes and protected cardiomyocytes and mice hearts from ferroptosis-driven EIC. In this study, our data elucidate that ferroptosis is involved in EIC, which is ignited by ATP6V0A2-dependent lysosomal acidification dysfunction. Our study provides a new potential therapeutic target for ameliorating EIC.

Coumarin-Based Photodegradable Hydrogels Enable Two-Photon Subtractive Biofabrication at 300†mm s-1.

Spatiotemporally controlled two-photon photodegradation of hydrogels has gained increasing attention for high-precision subtractive tissue engineering. However, conventional photolabile hydrogels often have poor efficiency upon two-photon excitation in the near-infrared (NIR) region and thus require high laser dosage that may compromise cell activity. As a result, high-speed two-photon hydrogel erosion in the presence of cells remains challenging. Here we introduce the design and synthesis of efficient coumarin-based photodegradable hydrogels to overcome these limitations. A set of photolabile coumarin-functionalized polyethylene glycol linkers are synthesized through a Passerini multicomponent reaction. After mixing these linkers with thiolated hyaluronic acid, semi-synthetic photodegradable hydrogels are formed in situ via Michael addition crosslinking. The efficiency of photodegradation in these hydrogels is significantly higher than that in nitrobenzyl counterparts upon two-photon irradiation at 780 nm. A complex microfluidic network mimicking the bone microarchitecture is successfully fabricated in preformed coumarin hydrogels at high speeds of up to 300 mm s-1 and low laser dosage down to 10 mW. Further, we demonstrate fast two-photon printing of hollow microchannels inside a hydrogel to spatiotemporally direct cell migration in 3D. Collectively, these hydrogels may open new avenues for fast laser-guided tissue fabrication at high spatial resolution.

Photocatalytic Hydrosilylation over Pt@UiO-66-NH2: Enhanced Activity and Polymerization Kinetics.

Metal-organic frameworks (MOFs) have shown great research and application value in various types of hydrosilylation reactions. However, studies on photocatalysis-induced hydrosilylation using MOFs are extremely rare. Metal nanoparticles (MNPs)@MOFs are extensively studied for their excellent structural tunability and photocatalytic activity, but there are few reports on their application in photocatalytic hydrosilylation. Here, a novel photocatalyst consisting of platinum (Pt) nanoparticles immobilized in a MOF framework is synthesized and used for photocatalytic hydrosilylation. The effects of various factors on hydrosilylation conversion are investigated, including catalyst concentration, substrate ratio, and irradiation intensity. Furthermore, the photoreactivity of the synthesized Pt catalyst is evaluated in the presence of different concentrations of 2-chlorothixanthone as a photosensitizer. It is noteworthy that the conversion of the reaction increases with increasing catalyst concentration or photosensitizer concentration, whereas increasing the polymethylhydrosiloxane content does not lead to a significant increase in conversion. This study demonstrates the potential of MNPs@MOFs as efficient photocatalysts for photoinduced hydrosilylation reactions and paves the way for future applications in this area.

Urolithin A improves Alzheimer's disease cognition and restores mitophagy and lysosomal functions.

BACKGROUND: Compromised autophagy, including impaired mitophagy and lysosomal function, plays pivotal roles in Alzheimer's disease (AD). Urolithin A (UA) is a gut microbial metabolite of ellagic acid that stimulates mitophagy. The effects of UA's long-term treatment of AD and mechanisms of action are unknown. METHODS: We addressed these questions in three mouse models of AD with behavioral, electrophysiological, biochemical, and bioinformatic approaches. RESULTS: Long-term UA treatment significantly improved learning, memory, and olfactory function in different AD transgenic mice. UA also reduced amyloid beta (Aß) and tau pathologies and enhanced long-term potentiation. UA induced mitophagy via increasing lysosomal functions. UA improved cellular lysosomal function and normalized lysosomal cathepsins, primarily cathepsin Z, to restore lysosomal function in AD, indicating the critical role of cathepsins in UA-induced therapeutic effects on AD. CONCLUSIONS: Our study highlights the importance of lysosomal dysfunction in AD etiology and points to the high translational potential of UA. HIGHLIGHTS: Long-term urolithin A (UA) treatment improved learning, memory, and olfactory function in Alzheimer's disease (AD) mice. UA restored lysosomal functions in part by regulating cathepsin Z (Ctsz) protein. UA modulates immune responses and AD-specific pathophysiological pathways.

Discrimination and prediction of Qingzhuan tea storage year using quantitative chemical profile combined with multivariate analysis: Advantages of MRMHR based targeted quantification metabolomics.

The duration of storage significantly influences the quality and market value of Qingzhuan tea (QZT). Herein, a high-resolution multiple reaction monitoring (MRMHR) quantitative method for markers of QZT storage year was developed. Quantitative data alongside multivariate analysis were employed to discriminate and predict the storage year of QZT. Furthermore, the content of the main biochemical ingredients, catechins and alkaloids, and free amino acids (FAA) were assessed for this purpose. The results show that targeted marker-based models exhibited superior discrimination and prediction performance among four datasets. The R2Xcum, R2Ycum and Q2cum of orthogonal projection to latent structure-discriminant analysis discrimination model were close to 1. The correlation coefficient (R2) and the root mean square error of prediction of the QZT storage year prediction model were 0.9906 and 0.63, respectively. This study provides valuable insights into tea storage quality and highlights the potential application of targeted markers in food quality evaluation.

Interactions between mitochondrial dysfunction and other hallmarks of aging: Paving a path toward interventions that promote healthy old age.

Current research on human aging has largely been guided by the milestone paper "hallmarks of aging," which were first proposed in the seminal 2013 paper by Lopez-Otin et al. Most studies have focused on one aging hallmark at a time, asking whether the underlying molecular perturbations are sufficient to drive the aging process and its associated phenotypes. More recently, researchers have begun to investigate whether aging phenotypes are driven by concurrent perturbations in molecular pathways linked to not one but to multiple hallmarks of aging and whether they present different patterns in organs and systems over time. Indeed, preliminary results suggest that more complex interactions between aging hallmarks must be considered and addressed, if we are to develop interventions that successfully promote healthy aging and/or delay aging-associated dysfunction and diseases. Here, we summarize some of the latest work and views on the interplay between hallmarks of aging, with a specific focus on mitochondrial dysfunction. Indeed, this represents a significant example of the complex crosstalk between hallmarks of aging and of the effects that an intervention targeted to a specific hallmark may have on the others. A better knowledge of these interconnections, of their cause-effect relationships, of their spatial and temporal sequence, will be very beneficial for the whole aging research field and for the identification of effective interventions in promoting healthy old age.

Salidroside promotes healthy longevity by interfering with HSP90 activity.

Aging is a risk factor for human health and quality of life. Screening and development of novel supplements and medications to combat aging and delay the incidence of age-related diseases are of great significance. In this study, salidroside (SA), a primary natural small molecule from Rhodiola rosea, was investigated regarding its effects on life and healthspan and the underlying molecular mechanism(s) of anti-aging and antioxidation. Our results showed that SA effectively prolonged lifespan and exhibited anti-aging and antioxidative properties. Computer-assisted methods, label-free interaction analysis, and in vitro assays showed that SA directly bound heat shock protein 90 (HSP90). Furthermore, SA significantly inhibited the ATPase activity of HSP90, affecting the interaction between HSP90 and its interacting proteins and the expression of downstream genes to regulate lifespan and the oxidative stress response. Our findings provided new insights into the pharmacological properties of SA across multiple species and its potential as an anti-aging drug.

Structural Engineering of Co-Metal-Organic Frameworks via Ce Incorporation for Improved Oxygen Evolution.

The rational design of metal-organic framework (MOF)-based electrocatalysts plays a key role in achieving high-efficiency oxygen evolution reaction (OER). Herein, a synergetic morphology and electronic structure engineering strategy are proposed to design a Co-MOF nanoflower grown on carbon paper via rare-earth cerium doping (CoCe-MOF/CP). Compared with Co-MOF/CP, the developed CoCe-MOF/CP exhibited superior OER performance with a low overpotential of 267 mV at 10 mA cm-2 and outstanding long-term stability over 100 h. Theoretical calculations show that the unique 4f valence electron structure of Ce induced charge redistribution of the Co-MOF surface through the strong Co 3d-O 2p-Ce 4f orbital electronic coupling below the Fermi level. Ce-doped plays a key role in the engineering of the electronic states of the Co sites to endow them with the optimal free energy landscape for enhanced OER catalytic activity. This work provides new insights into comprehending the RE-enhanced mechanism of electrocatalysis and provides an effective strategy for the design of MOF-based electrocatalysts.

Polyphenols in Oral Health: Homeostasis Maintenance, Disease Prevention, and Therapeutic Applications.

Polyphenols, a class of bioactive compounds with phenolic structures, are abundant in human diets. They have gained attention in biomedical fields due to their beneficial properties, including antioxidant, antibacterial, and anti-inflammatory activities. Therefore, polyphenols can prevent multiple chronic or infectious diseases and may help in the prevention of oral diseases. Oral health is crucial to our well-being, and maintaining a healthy oral microbiome is essential for preventing various dental and systemic diseases. However, the mechanisms by which polyphenols modulate the oral microbiota and contribute to oral health are still not fully understood, and the application of polyphenol products lies in different stages. This review provides a comprehensive overview of the advancements in understanding polyphenols' effects on oral health: dental caries, periodontal diseases, halitosis, and oral cancer. The mechanisms underlying the preventive and therapeutic effects of polyphenols derived from dietary sources are discussed, and new findings from animal models and clinical trials are included, highlighting the latest achievements. Given the great application potential of these natural compounds, novel approaches to dietary interventions and oral disease treatments may emerge. Moreover, investigating polyphenols combined with different materials presents promising opportunities for developing innovative therapeutic strategies in the treatment of oral diseases.

Revealing the chemical differences and their application in the storage year prediction of Qingzhuan tea by SWATH-MS based metabolomics analysis.

It's generally believed that the longer the storage, the better the quality of dark tea, but the chemical differences of Qingzhuan tea (QZT) with different storage years is still unclear. Herein, in this work, an untargeted metabolomic approach based on SWATH-MS was established to investigate the differential compounds of QZT with 0-9 years' storage time. These QZT samples were roughly divided into two categories by principal component analysis (PCA). After orthogonal projections to latent structures discriminant analysis (OPLS-DA), 18 differential compounds were putatively identified as chemical markers for the storage year variation of QZT. Heatmap visualization showed that the contents of catechins, fatty acids, and some phenolic acids significantly reduced, flavonoid glycosides, triterpenoids, and 8-C N-ethyl-2-pyrrolidinone-substituted flavan-3-ols (EPSFs) increased with the increase of storage time. Furthermore, these chemical markers were verified by the peak areas corresponding to MS2 ions from SWATH-MS. Based on the extraction chromatographic peak areas of MS and MS2 ions, a duration time prediction model was built for QZT with correlation coefficient R2 of 0.9080 and 0.9701, and RMSEP value of 0.85 and 1.24, respectively. This study reveals the chemical differences of QZT with different storage years and provides a theoretical basis for the quality evaluation of stored dark tea.

Rev1 deficiency induces a metabolic shift in MEFs that can be manipulated by the NAD+ precursor nicotinamide riboside.

Replication stress, caused by Rev1 deficiency, is associated with mitochondrial dysfunction, and metabolic stress. However, the overall metabolic alterations and possible interventions to rescue the deficits due to Rev1 loss remain unclear. Here, we report that loss of Rev1 leads to intense changes in metabolites and that this can be manipulated by NAD + supplementation. Autophagy decreases in Rev1-/- mouse embryonic fibroblasts (MEFs) and can be restored by supplementing the NAD+ precursor nicotinamide riboside (NR). The abnormal mitochondrial morphology in Rev1-/- MEFs can be partially reversed by NR supplementation, which also protects the mitochondrial cristae from rotenone-induced degeneration. In nematodes rev-1 deficiency causes sensitivity to oxidative stress but this cannot be rescued by NR supplementation. In conclusion, Rev1 deficiency leads to metabolic dysregulation of especially lipid and nucleotide metabolism, impaired autophagy, and mitochondrial anomalies, and all of these phenotypes can be improved by NR replenishment in MEFs.

Pooled analysis of frontal lobe transcriptomic data identifies key mitophagy gene changes in Alzheimer's disease brain.

Background: The growing prevalence of Alzheimer's disease (AD) is becoming a global health challenge without effective treatments. Defective mitochondrial function and mitophagy have recently been suggested as etiological factors in AD, in association with abnormalities in components of the autophagic machinery like lysosomes and phagosomes. Several large transcriptomic studies have been performed on different brain regions from AD and healthy patients, and their data represent a vast source of important information that can be utilized to understand this condition. However, large integration analyses of these publicly available data, such as AD RNA-Seq data, are still missing. In addition, large-scale focused analysis on mitophagy, which seems to be relevant for the aetiology of the disease, has not yet been performed. Methods: In this study, publicly available raw RNA-Seq data generated from healthy control and sporadic AD post-mortem human samples of the brain frontal lobe were collected and integrated. Sex-specific differential expression analysis was performed on the combined data set after batch effect correction. From the resulting set of differentially expressed genes, candidate mitophagy-related genes were identified based on their known functional roles in mitophagy, the lysosome, or the phagosome, followed by Protein-Protein Interaction (PPI) and microRNA-mRNA network analysis. The expression changes of candidate genes were further validated in human skin fibroblast and induced pluripotent stem cells (iPSCs)-derived cortical neurons from AD patients and matching healthy controls. Results: From a large dataset (AD: 589; control: 246) based on three different datasets (i.e., ROSMAP, MSBB, & GSE110731), we identified 299 candidate mitophagy-related differentially expressed genes (DEG) in sporadic AD patients (male: 195, female: 188). Among these, the AAA ATPase VCP, the GTPase ARF1, the autophagic vesicle forming protein GABARAPL1 and the cytoskeleton protein actin beta ACTB were selected based on network degrees and existing literature. Changes in their expression were further validated in AD-relevant human in vitro models, which confirmed their down-regulation in AD conditions. Conclusion: Through the joint analysis of multiple publicly available data sets, we identify four differentially expressed key mitophagy-related genes potentially relevant for the pathogenesis of sporadic AD. Changes in expression of these four genes were validated using two AD-relevant human in vitro models, primary human fibroblasts and iPSC-derived neurons. Our results provide foundation for further investigation of these genes as potential biomarkers or disease-modifying pharmacological targets.