Impaired Mitochondrial Function Research Articles

E2F2 Reprograms Macrophage Function By Modulating Material and Energy Metabolism in the Progression of Metabolic Dysfunction-Associated Steatohepatitis.

Macrophages are essential for the development of steatosis, hepatic inflammation, and fibrosis in metabolic dysfunction-associated steatohepatitis(MASH). However, the roles of macrophage E2F2 in the progression of MASH have not been elucidated. This study reveals that the expression of macrophage E2F2 is dramatically downregulated in MASH livers from mice and humans, and that this expression is adversely correlated with the severity of the disease. Myeloid-specific E2F2 depletion aggravates intrahepatic inflammation, hepatic stellate cell activation, and hepatocyte lipid accumulation during MASH progression. Mechanistically, E2F2 can inhibit the SLC7A5 transcription directly. E2F2 deficiency upregulates the expression of SLC7A5 to mediate amino acids flux, resulting in enhanced glycolysis, impaired mitochondrial function, and increased macrophages proinflammatory response in a Leu-mTORC1-dependent manner. Moreover, bioinformatics analysis and CUT &Tag assay identify the direct binding of Nrf2 to E2F2 promoter to promote its transcription and nuclear translocation. Genetic or pharmacological activation of Nrf2 effectively activates E2F2 to attenuate the MASH progression. Finally, patients treated with CDK4/6 inhibitors demonstrate reduced E2F2 activity but increased SLC7A5 activity in PBMCs. These findings indicated macrophage E2F2 suppresses MASH progression by reprogramming amino acid metabolism via SLC7A5- Leu-mTORC1 signaling pathway. Activating E2F2 holds promise as a therapeutic strategy for MASH.

Ivabradine prevents doxorubicin-induced cardiotoxicity via attenuating mitochondrial dysfunction and mitochondrial dynamic imbalance in H9C2 cells and rats

Abstract Background Doxorubicin (DOX) is a widely used chemotherapeutic agent, and cardiotoxicity is one of its well-known side effects, which is mediated by cardiac mitochondrial dysfunction. Ivabradine (IVA), a heart rate reduction drug, exerts benefits in various cardiac diseases as shown in both preclinical and clinical studies. However, its roles on DOX-induced cardiotoxicity have never been investigated. Purpose We determined whether IVA reduces DOX-induced cardiotoxicity by directly promoting mitochondrial function and maintaining mitochondrial dynamic balance. Methods H9C2 cells were divided into 4 groups: 1) Control, 2) DOX (10 μM, 25 h), 3) IVA (3 μM, 25 h), 4) Pretreatment with IVA (3 μM, 1 h), followed by DOX treatment (10 μM, 24 h). Then, cell viability and mitochondrial function were determined. In animal study, male Wistar rats were divided into 4 groups: 1) Control, 2) IVA (10 mg/kg/d, PO), 3) DOX (3 mg/kg/d, 6 doses, IP), 4) Co-treatment with IVA (10 mg/kg/d, PO) and DOX (3 mg/kg/d, 6 doses, IP) for 30 days. Then, heart rate, cardiac function, and cardiac mitochondrial dynamic proteins were determined. Result DOX reduced %cell viability of H9C2 cells via increasing cellular and mitochondrial oxidative stress, and reducing mitochondrial respiration (Figure 1A, B). Under DOX-induced cellular injury condition, pretreatment with IVA resulted in increasing %cell viability by 11%, decreasing cellular and mitochondrial oxidative stress; however, IVA did not affect mitochondrial respiration. Consistent with in vitro study, DOX induced cardiac dysfunction as indicated by reduced heart rate and ejection fraction, impaired mitochondrial function and mitochondrial dynamics balance (Figure 1C, D). Co-treatment with DOX and IVA had no further impact on heart rate. DOX-IVA attenuated cardiac mitochondrial dysfunction and mitochondrial dynamics imbalance, thus prevented cardiac dysfunction. Conclusion IVA effectively protected against DOX-induced cardiotoxicity through improvement of mitochondrial function, mitochondrial dynamics, and reduction of oxidative stress. These findings suggest the therapeutic potential of IVA in preventing Dox-induced cardiotoxicity.

Magnetic targeting enhances the neuroprotective function of human mesenchymal stem cell-derived iron oxide exosomes by delivering miR-1228-5p

BackgroundTreating mitochondrial dysfunction is a promising approach for the treatment of post-stroke cognitive impairment (PSCI). HuMSC-derived exosomes (H-Ex) have shown powerful therapeutic effects in improving mitochondrial function, but the specific effects are unclear and its brain tissue targeting needs to be further optimized.ResultsIn this study, we found that H-Ex can improve mitochondrial dysfunction of neurons and significantly enhance the cognitive behavior performance of MCAO mice in OGD/R-induced SHSY5Y cells and MCAO mouse models. Based on this, we have developed an exosome delivery system loaded with superparamagnetic iron oxide nanoparticles (Spion-Ex) that can effectively penetrate the blood-brain barrier (BBB). The research results showed that under magnetic attraction, Spion-Ex can more effectively target the brain tissue and significantly improve mitochondrial function of neurons after stroke. Meanwhile, we further confirmed that miR-1228-5p is a key factor for H-Ex to improve mitochondrial function and cognitive behavior both in vivo and in vitro. The specific mechanism is that the increase of miR-1228-5p mediated by H-Ex can inhibit the expression of TRAF6 and activate the TRAF6-NADPH oxidase 1 (NOX1) pathway, thereby exerting protective effects against oxidative damage. More importantly, we found that under magnetic attraction, Spion-Ex exhibited excellent cognitive improvement effects by delivering miR-1228-5p.ConclusionsOur research found that H-Ex has a good therapeutic effect on PSCI by increasing the expression of miR-1228-5p in PSCI, while H-Ex loaded with Spion-Ex exhibited more excellent effects on improving mitochondrial function and cognitive impairment under magnetic attraction, which can be used as a novel strategy for the treatment of PSCI.

The mechanism of paclitaxel induced damage on placental trophoblast cells

ObjectiveChemotherapy during pregnancy has a certain risk of causing a series of complications, such as miscarriage, premature birth, or fetal growth restriction, although the relationship between these complications and chemotherapy is currently unclear. This experiment focuses on the possible damage mechanism of the chemotherapeutic drug paclitaxel on placental trophoblast cells, and explores whether chemotherapy can affect pregnancy outcomes by directly damaging placental tissue.MethodsThis study explored the mechanism of paclitaxel induced damage on placental trophoblast cell lines JEG-3 and BEWO through immunofluorescence staining, Western blot experiments, cell flow cytometry, Seahorese cell metabolism experiments, and mouse modeling verification.ResultsThe experiment found that paclitaxel could induce JEG-3 and BEWO cells to produce reactive oxygen species (ROS), and elevate the ratio of Bax/Bcl-2 expression. Besides, paclitaxel mediated the reduction of mitochondrial membrane potential in JEG-3 and BEWO cells, causing damage and leading to mitochondrial autophagy and the occurrence of unfolded protein response. Paclitaxel inhibited the glycolysis rate of JEG-3 and BEWO cells, and leaded to impaired mitochondrial function, including decreased basal respiratory values, decreased respiratory reserve capacity, and proton leakage. In pregnant mice with tumor modeling, paclitaxel could cause DNA damage in placental tissue cells, and might lead to apoptosis of chemotherapy mice placental tissue cells and impairment of normal physiological functions.ConclusionPaclitaxel may directly or indirectly affect the normal physiological functions of placental trophoblast cells, including energy metabolism and protein synthesis dysfunction, which may be related to the adverse pregnancy outcomes caused by paclitaxel chemotherapy.

Monocytes perturbation implicated in the association of stress hyperglycemia with postoperative poor prognosis in non-diabetic patients with Stanford type-A acute aortic dissection

ObjectivesThe study aimed to investigate the interaction of intraoperative stress hyperglycemia with monocyte functions and their impact on major adverse events (MAEs) in acute aortic dissection (AAD) patients who underwent open repair surgery.MethodsA total of 321 adults who underwent open surgery for AAD at two tertiary medical centers in China were enrolled in the study. The primary endpoint was defined as the incidence and characteristics of perioperative stress hyperglycemia. The secondary endpoints included the incidence of postoperative MAEs, postoperative monocyte counts and inflammatory cytokine expression. Multi-logistic, linear regression and receiver operating characteristic (ROC) curve analyses were used to establish relationships between intraoperative time-weighted average glucose (TWAG), day-one postoperative monocyte counts, serum inflammatory cytokines and postoperative outcomes. In addition, in vitro experiments were conducted to evaluate changes in the inflammatory features of monocytes under high glucose conditions.ResultsIntraoperative hyperglycemia, as indicated by a TWAG level over 142 mg/dL, was associated with elevated postoperative monocyte counts and inflammatory cytokines, which correlated with extended intensive care unit (ICU) stays and worsened outcomes. In vitro, high glucose treatment induced mitochondrial impairment in monocytes, increased the release of inflammatory cytokines and the proportion of classical monocytes from AAD patients.ConclusionsIntraoperative stress hyperglycemia, in combination with day-one postoperative monocyte counts, were clinically significant for predicting adverse outcomes in AAD patients undergoing open repair surgery. Elevated glucose concentrations shaped the inflammatory features of monocytes in AAD by impairing mitochondrial functions.Graphical abstractHigh glucose-driven mitochondrial functional impairment mediates a more pronounced monocytic inflammatory state in Stanford type-A AAD.

Recent advances associated with cardiometabolic remodeling in diabetes-induced heart failure.

Diabetes mellitus (DM) is characterized by chronic hyperglycemia, and despite intensive glycemic control, the risk of heart failure in patients with diabetes remains high. Diabetes-induced heart failure (DHF) presents a unique metabolic challenge, driven by significant alterations in cardiac substrate metabolism, including increased reliance on fatty acid oxidation, reduced glucose utilization, and impaired mitochondrial function. These metabolic alterations lead to oxidative stress, lipotoxicity, and energy deficits, contributing to the progression of heart failure. Emerging research has identified novel mechanisms involved in the metabolic remodeling of diabetic hearts, such as autophagy dysregulation, epigenetic modifications, polyamine regulation, and branched-chain amino acid (BCAA) metabolism. These processes exacerbate mitochondrial dysfunction and metabolic inflexibility, further impairing cardiac function. Therapeutic interventions targeting these pathways-such as enhancing glucose oxidation, modulating fatty acid metabolism, and optimizing ketone body utilization-show promise in restoring metabolic homeostasis and improving cardiac outcomes. This review explores the key molecular mechanisms driving metabolic remodeling in diabetic hearts, highlights advanced methodologies, and presents the latest therapeutic strategies for mitigating the progression of DHF. Understanding these emerging pathways offers new opportunities to develop targeted therapies that address the root metabolic causes of heart failure in diabetes.

Machine Perfusion or Straight to Transplant? Predictive Value of Flavin Mononucleotide Levels in Flush Solution of Human Liver Allograft.

This study examined the predictive value of Flavin Mononucleotide (FMN) levels in the flush solution used during cold storage of donor livers on outcomes post-transplantation. Static cold storage for liver grafts induces hypoxia with subsequent impaired mitochondrial function and Flavin Mononucleotide (FMN) release upon reperfusion. This study enrolled 62 recipients who received whole liver grafts from donation after brain death (n=50) and circulatory death donors (n=12) between June 2022 and July 2023. FMN concentrations were measured in flush solutions on the back-table. ROC-curve analysis identified an FMN level cut-off for graft survival. Post-transplant outcomes were examined according to FMN levels. FMN level was significantly associated with graft survival, with an area-under-the-curve (AUC) of 0.858 (95%CI: 0.754-0.963, P<0.001), outperforming the donor risk index (AUC 0.571, 95%CI: 0.227-0.915, P=0.686). The study cohort was divided into low-FMN (<37.5ng/mL, n=40) and high-FMN groups (≥37.5ng/mL, n=22). The low-FMN group had superior one-year graft survival compared with the high-FMN group (100% vs. 77%, P=0.003). Levels of transaminases within 7 days post-transplant were significantly higher in the high-FMN group (P=0.003). The high-FMN group developed acute rejections (41% vs. 15%, P=0.023) and early allograft dysfunction (50% vs. 20%, P=0.014) more frequently. Median comprehensive complication index in the high-FMN group was significantly higher (54 [interquartile range, 40-78] vs. 42 [interquartile range, 28-52], P=0.017). The FMN level measured in donor livers' cold storage flush solution is a valid biomarker to predict post-transplant outcomes. Liver grafts with high FMN levels may benefit from machine perfusion to improve outcomes.

Upregulation of ALOX12−12-HETE pathway impairs AMPK-dependent modulation of vascular metabolism in ApoE/LDLR−/− mice

Mitochondrial dysfunction and 12-lipoxygenase (ALOX12)-derived 12(S)-HETE production have been associated with vascular inflammation and the pathogenesis of atherosclerosis. However, the role of ALOX12 in regulating vascular energy metabolism in vascular inflammation has not been studied to date. Using mitochondrial and glycolysis functional profiling with the Seahorse extracellular flux analyzer, metabolipidomics, and proteomic analysis (LC-MS/MS), we characterized alterations in vascular energy metabolism in 2- and 6-month-old ApoE/LDLR−/− vs. control C57BL/6 mice. We identified that aorta of 6-month-old ApoE/LDLR−/− mice displayed compromised mitochondrial metabolism manifested by the reduced expression of mitochondrial enzymes, impaired mitochondrial respiration, and consequently diminished respiratory reserve capacity. An increased flux through the glycolysis/lactate shuttle, the hexosamine biosynthetic pathway (HBP), and the pentose phosphate pathway (PPP) was also recognized. Interestingly, ALOX12−12-HETE was the most upregulated axis in eicosanoid metabolism and histological examinations indicated that ApoE/LDLR−/− mice showed increased aortic expression of ALOX12, particularly in early atherosclerotic plaque areas. Remarkably, the joint blocking of ALOX12 and activation of AMPK, but not AMPK activation alone, resulted in the reprogramming of vascular metabolism, with improved mitochondrial respiration and suppressed auxiliary pathways (HBP, PPP, itaconate shunt). In conclusion, excessive activation of the ALOX12–12-HETE pathway in vascular inflammation in early atherosclerosis inhibits AMPK-dependent regulation of vascular metabolism. Consequently, ALOX12 may represent a novel target to boost impaired vascular mitochondrial function in pro-atherosclerotic vascular inflammation.

AdipoRon Alleviates Liver Injury by Protecting Hepatocytes from Mitochondrial Damage Caused by Ionizing Radiation

Radiation liver injury is a common complication of hepatocellular carcinoma radiotherapy. It is mainly caused by irreversible damage to the DNA of hepatocellular cells directly by radiation, which seriously interferes with metabolism and causes cell death. AdipoRon can maintain lipid metabolism and stabilize blood sugar by activating adiponectin receptor 1 (AdipoR1). However, the role of AdipoRon/AdipoR1 in the regulation of ionizing radiation (IR)-induced mitochondrial damage remains unclear. In this study, we aimed to elucidate the roles of AdipoRon/AdipoR1 in IR-induced mitochondrial damage in normal hepatocyte cells. We found that AdipoRon treatment rescued IR-induced liver damage in mice and mitochondrial damage in normal hepatocytes in vivo and in vitro. AdipoR1 deficiency exacerbated IR-induced oxidative stress, mitochondrial dynamics, and biogenesis disorder. Mechanistically, the absence of AdipoR1 inhibits the activity of adenosine monophosphate-activated protein kinase α (AMPKα), subsequently leading to disrupted mitochondrial dynamics by decreasing mitofusin (MFN) and increasing dynamin-related protein 1 (DRP1) protein expression. It also controls mitochondrial biogenesis by suppressing the peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC1α) and transcription factor A (TFAM) signaling pathway, ultimately resulting in impaired mitochondrial function. To sum up, AdipoRon/AdipoR1 maintain mitochondrial function by regulating mitochondrial dynamics and biogenesis through the AdipoR1-AMPKα signaling pathway. This study reveals the significant role of AdipoR1 in regulating IR-induced mitochondrial damage in hepatocytes and offers a novel approach to protecting against damage caused by IR.

FgUbiH Is Essential for Vegetative Development, Energy Metabolism, and Antioxidant Activity in Fusarium graminearum

Fusarium head blight in wheat is mainly caused by Fusarium graminearum and results in significant economic losses. Coenzyme Q (CoQ) is ubiquitously produced across organisms and functions as a hydrogen carrier in energy metabolism. While UbiH in Escherichia coli serves as a hydroxylase in CoQ biosynthesis, its role in phytopathogenic fungi is not well understood. This study explored the role of the hydroxylase FgUbiH in F. graminearum. Using a FgUbiH deletion mutant, we observed reduced hyphal growth, conidial production, germination, toxin synthesis, and pathogenicity compared to the wild-type. A transcriptome analysis indicated FgUbiH’s involvement in regulating carbohydrate and amino acid metabolism. Deletion of FgUbiH impaired mitochondrial function, reducing adenosine triphosphate synthesis and increasing reactive oxygen species. Additionally, genes related to terpene skeleton synthesis and aldehyde dehydrogenase were downregulated. Our results underscore the importance of FgUbiH in F. graminearum’s growth, toxin production, and energy metabolism, aiding in the development of strategies for disease management.

Mechanisms of pathogenicity in the hypertrophic cardiomyopathy-associated TNNI3 c.235C > T variant

BackgroundHypertrophic cardiomyopathy (HCM) is typically manifested as a hereditary disorder, with 30 %–60 % of cases linked to cardiac sarcomere gene mutations. Despite numerous identified TNNI3 mutations associated with HCM, their severity, prevalence, and disease progression vary. The link between TNNI3 variants and phenotypes remains largely unexplored. This study aims to elucidate the impact of the TNNI3 c.235C > T mutation on HCM through clinical research and cell experiments and to explore its mechanism in HCM development. MethodsWe screened an HCM family for pathogenic gene mutations using gene sequencing. The proband and family members were assessed through electrocardiography, echocardiography, and cardiac MRI, and a pedigree map was created for disease prediction analysis. Mutant plasmids were constructed with the TNNI3 c.235C > T mutation and transfected into the AC16 human cardiomyocyte cell line to investigate the mutation's effects. ResultsThe TNNI3 c.235C > T mutation was identified as the disease-causing variant in the family. This mutation led to the upregulation of hypertrophy-associated genes ANP, BNP, and MYH7, increased cardiomyocyte size, and activation of the ERK signaling pathway. Further investigations revealed that the TNNI3 c.235C > T mutation impaired mitochondrial function, disrupted cardiomyocyte metabolism, and increased cellular autophagy and apoptosis. ConclusionsThe TNNI3 c.235C > T gene mutation may be a pathogenic factor for HCM, showing heterogeneous features and clinical phenotypes. This mutation induces myocardial hypertrophy, activates the ERK signaling pathway, and exacerbates mitochondrial dysfunction, apoptosis, and autophagy in cardiomyocytes. These findings provide insights into the mechanism of HCM caused by gene mutations and may inform HCM treatment strategies.

Maternal total sleep deprivation causes oxidative stress and mitochondrial dysfunction in oocytes associated with fertility decline in mice.

Previous studies have shown sleep deprivation is increasingly reported as one of the causes of female infertility. However, how and by what relevant mechanisms it affects female fertility remains unclear. In this study, female mice underwent 72 hours of total sleep deprivation (TSD) caused by rotating wheel or 2 different controls: a stationary wheel, or forced movement at night. Even though, there was no significant difference in the number of eggs ovulated by the TSD mice compared to the control groups. Overall levels of estrogen and FSH were lower throughout the estrus cycle. A total of 42 genes showed significant differential expression in GV oocytes after TSD by RNA sequencing (RNA-Seq). These included genes were enriched in gene ontology terms of mitochondrial protein complex, oxidoreductase activity, cell division, cell cycle G1/S phase transition, as well as others. The increased concentrations of reactive oxygen species (ROS) in germinal vesicle (GV) and metaphase II (MII) oocytes from TSD mice were observed, which might be induced by impaired mitochondrial function caused by TSD. The GV oocytes displayed increased mitochondrial DNA (mtDNA) copy number and a significant transient increase in inner mitochondrial membrane potential (Δψm) from the TSD mice probably due to compensatory effect. In contrast, MII oocytes in the TSD group showed a decrease in the mtDNA copy number and a lower Δψm compared with the controls. Furthermore, abnormal distribution of mitochondria in the GV and MII oocytes was also observed in TSD mice, suggesting mitochondrial dysfunction. In addition, abnormal spindle and abnormal arrangement of chromosomes in MII oocytes were markedly increased in the TSD mice compared with the control mice. In conclusion, our results suggest that TSD significantly alters the oocyte transcriptome, contributing to oxidative stress and disrupted mitochondrial function, which then resulted in oocyte defects and impaired early embryo development in female mice.

O-GlcNAc participates in the meiosis of aging oocytes by mediating mitochondrial function.

O-GlcNAc plays an important role in many age-related diseases. This study shows that O-GlcNAc participates in oocyte aging and that reducing O-GlcNAc levels in aging oocytes improves oocyte quality. With an increase in the mean age at parturition worldwide, female reproductive aging has become a key health problem. Advanced maternal age is reflected by decreased oocyte quality; however, the molecular mechanisms of oocyte aging are uncharacterized. O-linked N-acetylglucosamine (O-GlcNAc), a dynamic posttranslational modification, plays a critical role in the development of many age-related diseases; yet, it remains unclear whether and how O-GlcNAc participates in oocyte aging. Here, we found that global O-GlcNAc was elevated in normal biological aging mice oocytes (9 months), which were characterized by meiotic maturation failure and impaired mitochondrial function. Specifically, O-GlcNAc targeted the mitochondrial fission protein dynamic-related protein 1 to mediate mitochondrial distribution in the process of aging. Using the O-GlcNAcase (OGA) pharmacological inhibitor Thiamet-G and Oga knockdown (Oga-KD) to mimic the age-related high O-GlcNAc in young oocytes from 6-8 week-old mice mimicked the phenotype of oocyte aging. Moreover, reducing O-GlcNAc levels in aging oocytes restored spindle organization to improve oocyte quality. Our results demonstrate that O-GlcNAc is a key regulator of meiotic maturation that participates in the progression of oocyte aging.

Identification of the metabolic protein ATP5MF as a potential therapeutic target of TNBC

BackgroundTriple-negative breast cancer (TNBC), a distinct subtype of breast cancer, is characterized by its high invasiveness, high metastatic potential, proneness to relapse, and poor prognosis. Effective treatment regimens for non-BRCA1/2 mutation TNBC are still lacking. As a result, there is a pressing clinical necessity to develop novel treatment approaches for non-BRCA1/2 mutation TNBC.MethodsFor this research, the scRNA data was obtained from the GEO database, while the transcriptome data was obtained from the TCGA and METABRIC databases. Quality control procedures were conducted on single-cell sequencing data. and then annotation and the Copycat algorithm were applied for anlysis. Employing the high dimensional weighted gene coexpression network analysis (hdWGCNA) method, we analyzed the tumor epithelial cells from non-BRCA1/2 mutation TNBC to identify the functional module genes. PPI analysis and survival analysis were further emplyed to identify the key gene. siRNA-NC and siRNA-ATP5MF were transfected into two MDA-MB-231 and BT-549 TNBC cell lines. Cell growth was determined by CCK8 assay, colony formation and migration assay. Electron microscopy was used to examine the structure of mitochondria in cells. JC-1 staining was used to measure the potential of the mitochondrial membrane. A tumor xenograft animal model was established by injecting TNBC cells into nude mice. The animal model was usded to evaluated in vivo tumor response aftering ATP5MF silencing.ResultsUsing hdWGCNA, we have identified 136 genes in module 3. After PPI and survival analysis, we have identified ATP5MF as a potential therapeutic gene. High ATP5MF expression was associated with poor prognosis of non-BRCA1/2 mutation TNBC. The high expression of ATP5MF in TNBC tissues was evaluated using the TCGA database and IHC staining of clinical TNBC specimens. Silencing ATP5MF in two TNBC cell lines reduced the growth and colony formation of TNBC cells in vitro, and hindered the growth of TNBC xenografts in vivo. Additionally, ATP5MF knockdown impaired mitochondrial functions in TNBC cells.ConclusionIn summary, the metabolic protein ATP5MF plays a crucial role in the non-BRCA1/2 mutation TNBC cells, making it a potential novel diagnostic and therapeutic oncotarget for non-BRCA1/2 mutation TNBC.

AHR activation relieves deoxynivalenol-induced disruption of porcine intestinal epithelial barrier functions

Mycotoxins are ubiquitous natural pollutants that pose a serious threat to public health. Deoxynivalenol (DON) as one of the most prominent mycotoxins has a noticeable adverse effect on intestinal barrier function, which depends on the intestinal barrier integrity. However, the potential mechanisms and effective therapeutic strategies remain unclear. Aryl hydrocarbon receptor (AHR) has been implicated in the modulation of intestinal barrier function and inflammation. The study aims to investigate the unique role of AHR in mediating DON-induced intestinal epithelial barrier function. In the current study, we revealed that DON triggered mitochondrial structural damage and functional impairment, leading to oxidative stress and apoptosis in porcine jejunal epithelial cells (IPEC-J2). DON altered the integrity of IPEC-J2 cells by disrupting the distribution and function of tight junction proteins. Additionally, DON activated TNF-α/NF-κB/MLCK signaling pathway, thereby eliciting inflammatory response. Notably, DON inhibited AHR nuclear translocation and attenuated xenobiotic response element promoter activity and its target genes. However, overexpression of AHR mitigated DON-induced disruption of intestinal epithelial barrier functions by suppressing TNF-α/NF-κB/MLCK pathway in IPEC-J2 cells. Our findings indicate that AHR regulates intestinal epithelial barrier function and therefore is a novel therapeutic molecule for intestinal disorders.

Mitochondrial dysfunction, cause or consequence in neurodegenerative diseases?

Neurodegenerative diseases encompass a spectrum of conditions characterized by the gradual deterioration of neurons in the central and peripheral nervous system. While their origins are multifaceted, emerging data underscore the pivotal role of impaired mitochondrial functions and endolysosomal homeostasis to the onset and progression of pathology. This article explores whether mitochondrial dysfunctions act as causal factors or are intricately linked to the decline in endolysosomal function. As research delves deeper into the genetics of neurodegenerative diseases, an increasing number of risk loci and genes associated with the regulation of endolysosomal and autophagy functions are being identified, arguing for a downstream impact on mitochondrial health. Our hypothesis centers on the notion that disturbances in endolysosomal processes may propagate to other organelles, including mitochondria, through disrupted inter-organellar communication. We discuss these views in the context of major neurodegenerative diseases including Alzheimer's and Parkinson's diseases, and their relevance to potential therapeutic avenues.

Downregulation of glucose-energy metabolism via AMPK signaling pathway in granulosa cells of diminished ovarian reserve patients

Glucose metabolism plays a crucial role in the function of granulosa cells (GCs) and the development of follicles. In cases of diminished ovarian reserve (DOR), alterations in these processes can impact female fertility. This study aims to investigate changes in glucose-energy metabolism in GCs of young DOR patients aged 20 to 35 years and their correlation with the onset and progression of DOR. 72 DOR cases and 75 women with normal ovarian reserve (NOR) as controls were included based on the POSEIDON and Bologna criteria. Samples of GCs and follicular fluid (FF) were collected for a comprehensive analysis involving transcriptomics, metabolomics, RT-qPCR, JC-1 staining, and flow cytometry. The study identified differentially expressed genes and metabolites in GCs of DOR and NOR groups, revealing 7 common pathways related to glucose-energy metabolism, along with 11 downregulated genes and 14 metabolites. Key substances in the glucose-energy metabolism pathway, such as succinate, lactate, NADP, ATP, and ADP, showed decreased levels, with the DOR group exhibiting a reduced ADP/ATP ratio. Downregulation of genes involved in glycolysis (HK, PGK, LDH1), the TCA cycle (CS), and gluconeogenesis (PCK) was observed, along with reduced glucose content and expression of glucose transporter genes (GLUT1 and GLUT3) in DOR GCs. Additionally, decreased AMPK pathway activity and impaired mitochondrial function in DOR suggest a connection between mitochondrial dysfunction and disrupted energy metabolism. Above all, the decline in glucose-energy metabolism in DOR is closely associated with its onset and progression. Reduced glucose uptake and impaired mitochondrial function in DOR GCs lead to internal energy imbalances, hindering the AMPK signaling pathway, limiting energy production and supply, and ultimately impacting follicle development and maturation.

Effect of Mesenchymal Stem Cell–Derived Extracellular Vesicles Induced by Advanced Glycation End Products on Energy Metabolism in Vascular Endothelial Cells

IntroductionAdvanced glycation end products (AGEs) play a critical role in the development of vascular diseases in diabetes. While stem cell therapies often involve exposure to AGEs, the impact of this environment on extracellular vesicles (EVs) and endothelial cell metabolism remains unclear. MethodsHuman umbilical cord mesenchymal stem cells (MSC) were treated with either 0 ng/mL or 100 ng/mL AGEs in a serum-free medium for 48 hours, after which MSC-EVs were isolated. The EVs were characterized for morphology, particle size, and protein markers of MSC-EVs, and performed miRNA sequencing to identify differentially expressed miRNAs. MSC-EVs were co-cultured with HUVEC cells to assess effects on cell viability, metabolic activity, oxidative stress, and antioxidant capacity. Tube formation and glucose transporter protein analyses were conducted to evaluate the angiogenic ability and glucose metabolism capacity. ResultsMSC-EVs ranged from 30 to 150 nm, consistenting with exosomal properties. AGEs treatment reduced MSC viability but had minimal effect on EV morphology and protein markers. miRNAs sequencing showed downregulation of hsa-miR-223-3p, hsa-miR-126-3p_R-1, with upregulation of hsa-miR-574-5p, implicating changes in glycolytic and oxidative phosphorylation pathways. MSC-EVs treated with AGEs decreased HUVEC viability (P<0.05), pH (P<0.05), ATP metabolism (P<0.05), glucose metabolism (P<0.05), while enhancing glycolysis processes, including glycolytic activity, capacity, and reserve (P<0.05). This likely resulted from impaired mitochondrial function, including reduced ATP production, maximal respiration, basal respiration, and spare respiratory capacity (P<0.05), or increased ROS (P<0.05) and G6PD activity (P<0.05). Additionally, AGEs reduced GLUT1, GLUT3, GLUT4, and SCO2 expression (P<0.05), along with angiogenic capacity (P<0.05) in HUVEC cells. ConclusionExposure to AGEs diminishes the therapeutic potential of MSC-derived EVs by disrupting energy metabolism and promoting metabolic reprogramming in endothelial cells. These findings suggest that adjusting the dosage or frequency of MSC-EVs may enhance their efficacy for treating diabetes-related vascular conditions. Further research is warranted to evaluate AGEs' broader impact on various cell types and metabolic pathways for improved exosome-based therapies.

The mitochondrial function of peripheral blood mononuclear cells in frail older patients

BackgroundFrailty increases the incidence of geriatric syndromes and even the risk of death in old adults. However, the diagnostic criteria for frailty are inconsistent because of complex pathological processes and diverse clinical manifestations. To determine the effective biomarker and recognize frail status early, we investigated the correlation of mitochondrial morphology and function of human peripheral blood mononuclear cells (PBMCs) with frailty status in older adults. MethodsThis Cross-sectional study followed 393 participants (aged 25–100 years, female 31.04 %) from the First Affiliated Hospital of Nanjing Medical University. The frailty status of subjects was assessed by the physical frailty phenotype (PFP) scale. We analyzed mitochondria functions including mitochondria copy number (mtDNAcn), the mRNA expressions of mitochondrial dynamics-related genes mitofusin 1(MFN1), mitofusin 2(MFN2), optic atrophy protein-1(OPA1), fission protein-1(FIS1) and dynamin-related protein 1(DRP1), mitochondrial oxidative respiration and reactive oxygen species(ROS) levels in PBMCs. Mitochondria morphology, size, and number were observed by transmission electron microscopy (TEM). ResultsAfter adjustment for sex and BMI, mtDNAcn, the mRNA expression of FIS1, mitochondrial respiratory function (proton leak, maximum oxygen consumption, and respiratory reserve) and ROS level were significantly correlated with age (P = 0.031, 0.030, 0.042, 0.003, 0.002, 0.022, respectively). After correcting for age, sex, and BMI, mtDNAcn and the mRNA expression of OPA1 were correlated with 4 m gait speed respectively (P = 0.003, 0.028, respectively). Compared with non-frail people, mtDNAcn, the mRNA expression of MFN1, mitochondrial basal respiration, proton leak, maximum oxygen consumption, ATP production and space capacity were significantly decreased in frail older adults (P = 0.013, 0.036, 0.026, 0.024, 0.012, 0.032, 0.020, respectively). ROS levels were significantly increased in the frail group (P = 0.016). Compared with non-frail people, the number, length, and perimeter, area of mitochondria were reduced in frail group under TEM (all P < 0.001). ConclusionMitochondrial dysfunctions (decreased mtDNAcn, impaired mitochondrial morphology, imbalanced mitochondrial dynamic, impaired mitochondrial respiratory function, and increased ROS levels) were significantly correlated with frail status.

Alterations of Hepatic Lipidome Occur in a Gouty Model: A Shotgun Lipidomics Study.

Liver injury, such as nonalcoholic fatty liver disease, is a common symptom observed in patients with gout/hyperuricaemia. However, the exact mechanisms are still unclear. There is ongoing controversy about whether representative agents like colchicine and febuxostat, commonly used to manage gout, could also help prevent the liver injury. Liver plays a crucial role in uric acid (UA) production and lipid metabolism. Thus, the study aimed to investigate the aberrant lipid metabolism in the liver during injury and the effects of these drugs. An advanced multi-dimensional mass spectrometry-based shotgun lipidomics technology was employed for class-targeted lipid analysis of cellular lipidomes in hepatic tissue of a gouty model induced by a combination of monosodium urate crystals and high-fat diet with or without treatment with colchicine and febuxostat. Serum UA, blood urea nitrogen, creatinine, proinflammatory cytokines, expression of AMP-activated protein kinase protein, footpad histopathology, and footpad swelling and pain threshold of these mice were assessed to evaluate the progression of gout. Lipidomics analysis clearly demonstrated that the ectopic fat accumulation as well as changes in fatty acyls composition in TAG pool, impaired mitochondrial function resulted by decreased tetra 18:2 cardiolipin, and reduced 4-hydroxyalkenal bioavailability in liver tissue could contribute to liver damage to the gouty model. Treatment with colchicine or febuxostat not only ameliorated gouty symptoms but also corrected these abnormal hepatic lipid metabolism patterns. This study shed light on underlying mechanism(s) for liver injury in gout/hyperuricaemia and suggested that administration of drugs like colchicine and febuxostat could prevent liver injury.