Mitochondria-related Pathways Research Articles

Mitochondrial dysfunction in Alzheimer’s disease: a key frontier for future targeted therapies

Alzheimer’s disease (AD) is the most common neurodegenerative disorder, accounting for approximately 70% of dementia cases worldwide. Patients gradually exhibit cognitive decline, such as memory loss, aphasia, and changes in personality and behavior. Research has shown that mitochondrial dysfunction plays a critical role in the onset and progression of AD. Mitochondrial dysfunction primarily leads to increased oxidative stress, imbalances in mitochondrial dynamics, impaired mitophagy, and mitochondrial genome abnormalities. These mitochondrial abnormalities are closely associated with amyloid-beta and tau protein pathology, collectively accelerating the neurodegenerative process. This review summarizes the role of mitochondria in the development of AD, the latest research progress, and explores the potential of mitochondria-targeted therapeutic strategies for AD. Targeting mitochondria-related pathways may significantly improve the quality of life for AD patients in the future.

INF2 mutations cause kidney disease through a gain-of-function mechanism.

Heterozygosity for inverted formin-2 (INF2) mutations causes focal segmental glomerulosclerosis (FSGS) with or without Charcot-Marie-Tooth disease. A key question is whether the disease is caused by gain-of-function effects on INF2 or loss of function (haploinsufficiency). Despite established roles in multiple cellular processes, neither INF2 knockout mice nor mice with a disease-associated point mutation display an evident kidney or neurologic phenotype. Here, we compared responses to puromycin aminonucleoside (PAN)-induced kidney injury between INF2 R218Q and INF2 knockout mice. R218Q INF2 mice are susceptible to glomerular disease, in contrast to INF2 knockout mice. Colocalization, coimmunoprecipitation analyses, and cellular actin measurements showed that INF2 R218Q confers a gain-of-function effect on the actin cytoskeleton. RNA expression analysis showed that adhesion and mitochondria-related pathways were enriched in the PAN-treated R218Q mice. Both podocytes from INF2 R218Q mice and human kidney organoids with an INF2 mutation (S186P) recapitulate adhesion and mitochondrial phenotypes. Thus, gain-of-function mechanisms drive INF2-related FSGS and explain this disease's autosomal dominant inheritance.

Abstract 4121970: Early to Mid-Gestational Testosterone Excess Sex-specifically Reprograms Cardiac Transcriptome and Metabolome Profiles of Sheep Fetuses

Exposure of sheep to excess testosterone (T) from days 30-90 of gestation (term 147 days) perturbs maternal systemic lipidome in late gestation, induces fetal growth restriction and sexually dimorphic perturbation in the cardiac left ventricular (LV) transcriptome in gestational (GD) day 90 fetuses culminating in cardiometabolic dysfunction in adult female offspring. We hypothesized that the detrimental impact of prenatal T excess on fetal cardiac transcriptome is a programmed event that will persist even after cessation of excess T exposure and will be accompanied by changes in fetal metabolome. Pregnant ewes were injected with 100 mg intramuscular T propionate or vehicle (C), twice weekly from GD 30-90. On GD120±5, 30 days after cessation of T treatment fetal weights were recorded, left ventricle (LV) tissue and fetal plasma processed for transcriptomics by RNA sequencing and metabolomics analysis (Female C (FC) n=6, T (FT) n=7; Male C (MC) n=6, T (MT) n=7). LV transcriptome-based pathways enrichment analysis revealed 1) downregulation of pathways associated with oxidative phosphorylation, citric acid cycle, pyruvate metabolism; 2) upregulation of TGF-β signaling pathway in T fetuses compared to C (p<0.05, FDR<0.1); 3) selective downregulation of the glycolytic pathway in MT relative to MC as opposed to downregulation of mitochondria-related pathways in FT vs FC (p<0.05, FDR<0.1). LV lipidomics analyses found glycerophospholipids and sphingolipids as main class lipid metabolites to be enriched in FT relative to FC fetuses (p<0.05, ER>1). Fetal systemic lipidome main class metabolites enriched (p<0.05, ER>2) in T vs C fetuses included 1) sphingomyelins in both sexes 2) fatty acyls metabolites only in MT vs MC as opposed to glycerophospholipids only in FT vs FC. LV polar metabolites enriched (p<0.05, ER>2) included 1) arginine&proline metabolism pathways in T vs C in both sexes 2) nicotinate and nicotinamide metabolism only in MT vs MC (p<0.05, ER>3), and porphyrin, riboflavin metabolism and N-glycan biosynthesis pathways only in FT vs FC. Systemic polar metabolites enriched (p<0.05, ER>2) included 1) D-amino acid metabolism pathways in T vs. C, 2) valine, leucine, and isoleucine pathways only in FT vs FC and glycerophospholipid and sphingolipid metabolism only in MT vs MC. These results suggest persistence of sex-specific perturbation in fetal transcriptome and systemic and cardiac metabolome in late gestational fetuses exposed to prenatal T excess.

Comprehensive analysis of a necroptosis-associated diagnostic signature for myelodysplastic syndromes based on single-cell RNA-seq and bulk RNA-seq

BackgroundMyelodysplastic syndromes (MDS) are heterogeneous and clonal hematological disorders. The role and mechanism of necroptosis in MDS remain poorly understood.MethodsmRNA expression profiles and single-cell RNA-sequencing (scRNA-seq) data were sourced from the GEO database. ScRNA-seq data were processed using the “Seurat” package. After cell annotation, necroptosis-related scores (NRscores) for each cell were calculated using the “UCell” package. Differentially expressed genes (DEGs) and their associated biological functions in NRscore-related cell populations were identified. Additionally, DEGs and necroptosis-related genes (DE-NRGs) between MDS patients and healthy controls were identified. Consensus clustering was employed to classify MDS patients into distinct subclusters based on DE-NRGs. The biological functions and immune characteristics of these classifications were analyzed. Prognostic gene signatures were determined using LASSO and SVM-RFE analyses, and a nomogram was constructed based on the prognostic gene signature.ResultsA total of 12 cell types were identified in MDS and healthy controls. NRscore was found to be elevated in monocytes and common lymphoid precursors (CLPs). Enrichment analysis revealed that monocytes and CLPs with high NRscore were associated with mitochondria-related and immune-related pathways. Eleven DEGs in monocytes and CLPs between MDS patients and healthy controls were identified. Additionally, 13 DE-NRGs were identified from 951 DEGs between MDS and healthy controls. MDS patients were classified into two distinct subclusters based on these 13 DE-NRGs, revealing several immune-related processes and signaling pathways. Differences in immune subpopulations between the two subclusters were observed. A necroptosis-related diagnostic gene signature (IRF9, PLA2G4A, MLKL, BAX, JAK2, and STAT3) was identified as predictive of MDS prevalence.ConclusionNecroptosis plays a role in MDS progression by inducing inflammation. A novel necroptotic gene signature has been developed to distinguish and diagnose MDS at early stages of the disease.

Association of serum lactate dehydrogenase with prognosis and tumor metabolism in patients with hepatocellular carcinoma treated with atezolizumab plus bevacizumab therapy.

Treatment outcomes are predicted by analyzing peripheral blood markers such as serum lactate dehydrogenase (LDH). We conducted this study to investigate whether serum LDH levels can predict the prognosis of patients treated with atezolizumab plus bevacizumab (ATZ/BEV) therapy for hepatocellular carcinoma (HCC) and whether LDH levels correlate with metabolic changes. We enrolled 66 HCC patients treated with ATZ/BEV. Based on the change in serum LDH levels before and after treatment, the patients were divided into two groups, and the prognosis of each group was examined. Moreover, the association of LDH levels with tumor metabolism was analyzed by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). There were 32 patients categorized as the LDH-decrease group. Kaplan-Meier survival analysis indicated worse progression-free survival (PFS) in the LDH-increase group than in the LDH-decrease group (p = 0.0029). Multivariate analysis showed that an increase in the LDH level was an independent risk factor for worse PFS (p = 0.0045). The baseline LDH level correlated significantly with a high maximum standardized uptake value of 18F-FDG, according to the PET/CT findings. Transcriptomic analyses of specimens resected after ATZ/BEV therapy showed downregulated mitochondria-related pathways. Serum LDH levels are a potential prognostic marker and an indicator of tumor metabolism.

Identification of key mitochondria-related genes and their relevance to the immune system linking Parkinson's disease and primary Sjögren's syndrome through integrated bioinformatics analyses

BackgroundMitochondria are the metabolic hubs of cells, regulating energy production and antigen presentation, which are essential for activation, proliferation, and function of immune cells. Recent evidence indicates that mitochondrial antigen presentation may have an impact on diseases such as Parkinson's disease (PD) and autoimmune diseases. However, there is limited knowledge about the mechanisms that regulate the presentation of mitochondrial antigens in these diseases. MethodsIn the current study, RNA sequencing was performed on labial minor salivary gland (LSG) from 25 patients with primary Sjögren's syndrome (pSS) and 14 non-pSS aged controls. Additionally, we obtained gene expression omnibus datasets associated with PD patients from NCBI Gene Expression Omnibus (GEO) databases. Single-sample Gene Set Enrichment Analysis (ssGSEA), ESTIMATE and Spearman correlations were conducted to explore the association between mitochondrial related genes and the immune system. Furthermore, we applied weighted Gene Co-expression Network Analysis (WGCNA) to identify hub mitochondria-related genes and investigate the correlated networks in both diseases. Single cell transcriptome analysis, immunohistochemical (IHC) staining and quantitative real-time PCR (qRT–PCR) were used to verify the activation of the hub mitochondria-related pathway. Pearson correlations and the CIBERSORT algorithms were employed to further reveal the correlation between hub mitochondria-related pathways and immune infiltration. ResultsThe transcriptome analysis revealed the presence of overlapping mitochondria-related genes and mitochondrial DNA damage in patients with pSS and PD. Reactive oxygen species (ROS), the senescence marker p53, and the inflammatory markers CD45 and Bcl-2 were found to be regionally distributed in LSGs of pSS patients. WGCNA analysis identified the STING pathway as the central mitochondria-related pathway closely associated with the immune system. Single cell analysis, IHC staining, and qRT-PCR confirmed the activation of the STING pathway. Subsequent, bioinformatic analysis revealed the proportion of infiltrating immune cells in the STING-high and STING-low groups of pSS and PD. Furthermore, the study demonstrated the association of the STING pathway with innate and adaptive immune cells, as well as functional cells, in the immune microenvironment of PD and pSS. ConclusionOur study uncovered a central pathway that connects mitochondrial dysfunction and the immune microenvironment in PD and pSS, potentially offering valuable insights into therapeutic targets for these conditions.

Spontaneous metastasis xenograft models link CD44 isoform 4 to angiogenesis, hypoxia, EMT and mitochondria-related pathways in colorectal cancer.

Hematogenous metastasis limits the survival of colorectal cancer (CRC) patients. Here, we illuminated the roles of CD44 isoforms in this process. Isoforms 3 and 4 were predominantly expressed in CRC patients. CD44 isoform 4 indicated poor outcome and correlated with epithelial-mesenchymal transition (EMT) and decreased oxidative phosphorylation (OxPhos) in patients; opposite associations were found for isoform 3. Pan-CD44 knockdown (kd) independently impaired primary tumor formation and abrogated distant metastasis in CRC xenografts. The xenograft tumors mainly expressed the clinically relevant CD44 isoforms 3 and 4. Both isoforms were enhanced in the paranecrotic, hypoxic tumor regions but were generally absent in lung metastases. Upon CD44 kd, tumor angiogenesis was increased in the paranecrotic areas, accompanied by reduced hypoxia-inducible factor-1α and CEACAM5 but increased E-cadherin expression. Mitochondrial genes and proteins were induced upon pan-CD44 kd, as were OxPhos genes. Hypoxia increased VEGF release from tumor spheres, particularly upon CD44 kd. Genes affected upon CD44 kd in xenografts specifically overlapped concordantly with genes correlating with CD44 isoform 4 (but not isoform 3) in patients, validating the clinical relevance of the used model and highlighting the metastasis-promoting role of CD44 isoform 4.

Comparative transcriptome profiling reveals RNA splicing alterations and biological function in patients exposed to occupational noise.

Genetic factors play an important role in susceptibility to noise-induced hearing loss (NIHL). Alternative splicing (AS) is an essential mechanism affecting gene expression associated with disease pathogenesis at the post-transcriptional level, but has rarely been studied in NIHL. To explore the role of AS in the development of NIHL, we performed a comprehensive analysis of RNA splicing alterations by comparing the RNA-seq data from blood samples from NIHL patients and subjects with normal hearing who were exposed to the same noise environment. A total of 356 differentially expressed genes, including 23 transcription factors, were identified between the two groups. Of particular note was the identification of 56 aberrant alternative splicing events generated by 41 differentially expressed genes between the two groups, with exon skipping events accounting for 54% of all the differentially alternative splicing (DAS) events. The results of functional enrichment analysis showed that these intersecting DAS genes and differentially expressed genes were significantly enriched in autophagy and mitochondria-related pathways. Together, our findings provide insights into the role of AS events in susceptibility and pathogenesis of NIHL.

Dexamethasone inhibits IL-8 via glycolysis and mitochondria-related pathway to regulate inflammatory pain

BackgroundDexamethasone (Dexa) has been recently found to exert an analgesic effect, whose action is closely related to IL-8. However, whether dexamethasone induces antinociception via glycolysis and mitochondria-related pathways is still unclear.MethodsRight hind paw inflammatory pain in mice was induced by intraplantar injection of Freund’s Complete Adjuvant (FCA). Von Frey test was then used to measure the paw withdrawal threshold. The detection of glycolysis and mitochondrial pathway-related proteins and IL-8 were determined by Western blot and ELISA. The potential interaction between Dexa and fructose-1,6-bisphosphate (FBP, a PKM2 activator) was examined by simulation predictions using molecular docking.ResultsIntrathecal administration of Dexa (20 µg/20 µL) had an obvious analgesic effect in FCA-treated mice, which was counteracted by the glycolysis inhibitor 2-deoxyglucose (2-DG, 5 mg/20 µL) or the mitochondria-related pathway inhibitor oligomycin complex (Oligo, 5 µg/20 µL). In the glycolysis pathway, Dexa decreased GLUT3 and had no impact on HIF-1α expression during FCA-induced inflammation. Additionally, Dexa further increased the PKM2 level, accompanied by the formation of hydrogen bonds between Dexa and the PKM2 activator fructose-1,6-bisphosphate (FBP). In the mitochondrial pathway, Dexa downregulated the expression of Mfn2 protein but not the PGC-1α and SIRT-1 levels in the spinal cord. Moreover, both 2-DG and Oligo decreased Mfn2 expression. Finally, IL-8 level was reduced by the single or combined administration of Dexa, 2-DG, and Oligo.ConclusionDexa attenuated IL-8 expression via glycolysis and mitochondrial pathway-related proteins, thus mediating the analgesic effect during inflammatory pain.

Comprehensive analysis of the lysine succinylome in fish oil-treated prostate cancer cells.

Prostate cancer (PCa) poses a significant health threat to males, and research has shown that fish oil (FO) can impede PCa progression by activating multiple mitochondria-related pathways. Our research is focused on investigating the impact of FO on succinylation, a posttranslational modification that is closely associated with mitochondria in PCa cells. This study employed a mass spectrometry-based approach to investigate succinylation in PCa cells. Bioinformatics analysis of these succinylated proteins identified glutamic-oxaloacetic transaminase 2 (GOT2) protein as a key player in PCa cell proliferation. Immunoprecipitation and RNA interference technologies validated the functional data. Further analyses revealed the significance of GOT2 protein in regulating nucleotide synthesis by providing aspartate, which is critical for the survival and proliferation of PCa cells. Our findings suggest that FO-dependent GOT2 succinylation status has the potential to inhibit building block generation. This study lays a solid foundation for future research into the role of succinylation in various biological processes. This study highlights the potential use of FO as a nutrition supplement for managing and slowing down PCa progression.

Renal mitochondrial metabolism is differentially regulated in male and female kidneys in Ang II -- induced hypertension

Introduction. In 2020, more than 670,000 deaths in the United States had hypertension as a primary or contributing cause. Females generally exhibit less susceptibility to hypertensive renal damage compared to males. It is established that renal mitochondrial dysfunction and associated oxidative stress contribute to hypertension development. Our previous studies have shown that healthy renal mitochondria in the absence of hypertension exhibit sex differences in antioxidant protein abundance, ROS production, and oxygen consumption rates. We hypothesized here that in hypertensive state mitochondrial metabolism in male and female kidneys differentially regulates tissue damage and ultimately hypertension in females. Methods. To address our hypothesis, we used 11-week-old male and female Sprague Dawley rats infused with Angiotensin II (400 ng/kg/min to induce hypertension) or vehicle for 3 weeks via a s.c. osmotic pump. Mitochondria were isolated from the renal cortex and medulla of these rats; mitochondrial membrane potential and H 2 O 2 production were measured by spectrofluorimetry using TMRM and Amplex Red dyes. Two-way ANOVA was utilized for statistical analysis in OriginPro. Metabolic profiles of renal cortices and medullae were generated using UHPLC-HRMS, and metabolites were identified by retention time exact mass using MAVEN and MetaboAnalyst software. Results. Spectrofluorimetry showed decreased membrane potential in both male and female renal medulla in animals infused with Ang II compared to vehicle (p<0.001), while in cortex this difference was only recorded in females (p=0.03). Ang II-infusion reduced H 2 O 2 production in the renal cortex and medulla of female rats (p<0.001) compared to sham groups, while this was not observed in males. In both Ang II and vehicle-infused groups, females maintained higher H 2 O 2 production compared to males. UHPLC-HRMS identified 147 mitochondria-related metabolites in each group. Ang II infusion increased TCA cycle and purine metabolites as well as amino acids in the cortex of both sexes and in male medulla, whereas these changes were not revealed in the female medulla. Interestingly, females exhibited a decrease in amino acid metabolism in the renal medulla. In contrast to the male cortex, the female cortex is responding to oxidative stress induced by hypertension by altering arginine biosynthesis and metabolism. Arginine is a biosynthetic precursor to putrescine, which is involved in polyamine biosynthesis. Conclusions. Male and female kidneys employ divergent metabolic mitochondria-related pathways in hypertensive state. The male cortex may rely more on protein degradation to produce uric acid, an antioxidant, while the female cortex utilizes protein degradation and polyamine biosynthesis in oxidative stress management. R01HL148114 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Comparative transcriptome analysis of the mechanism difference in heat stress response between indica rice cultivar "IR64" and japonica cultivar "Koshihikari" at the seedling stage.

Heat stress (HS) has become a major abiotic stress in rice, considering the frequency and intensity of extreme hot weather. There is an urgent need to explore the differences in molecular mechanisms of HS tolerance in different cultivars, especially in indica and japonica. In this study, we investigated the transcriptome information of IR64 (indica, IR) and Koshihikari (japonica, Kos) in response to HS at the seedling stage. From the differentially expressed genes (DEGs) consistently expressed at six time points, 599 DEGs were identified that were co-expressed in both cultivars, as well as 945 and 1,180 DEGs that were specifically expressed in IR and Kos, respectively. The results of GO and KEGG analysis showed two different HS response pathways for IR and Kos. IR specifically expressed DEGs were mainly enriched in chloroplast-related pathways, whereas Kos specifically expressed DEGs were mainly enriched in endoplasmic reticulum and mitochondria-related pathways. Meanwhile, we highlighted the importance of NO biosynthesis genes, especially nitrate reductase genes, in the HS response of IR based on protein-protein interaction networks. In addition, we found that heat shock proteins and heat shock factors play very important roles in both cultivars. This study not only provides new insights into the differences in HS responses between different subspecies of rice, but also lays the foundation for future research on molecular mechanisms and breeding of heat-tolerant cultivars.

Mitochondrial-Localized Protein Transcript Abundance can Predict the Prognosis of Endometrial Carcinoma: A Retrospective Analysis

Background: Uterine corpus endometrial carcinoma (UCEC) is among the most common malignant tumors affecting women’s reproductive systems. Patients’ postoperative survival results differ greatly because of the significant heterogeneity of UCEC. The activity of mitochondria in UCEC and normal endometrium was shown to be substantially different. The objective of this research was the creation of better tools for predicting UCEC patient survival to provide more accurate and effective treatment strategies. Methods: The UCEC RNA sequencing data was accessed at the Cancer Genome Atlas project, containing 539 UCEC samples and 35 tumor-adjacent tissue. The differentially expressed genes (DEGs) were identified through the R package ‘limma’. The mitochondrial protein genes were subjected to a Cox regression analysis using the absolute shrinkage and selection operator (LASSO). The differences (variations) in the biological processes between the patient groups were examined through gene set variation analysis (GSVA). Results: Results of gene set enrichment analysis (GSEA) analysis revealed that mitochondria-related pathways were more active in endometrial cancer than in tumor-adjacent tissue. Through the screening of LASSO-cox and multi-cox analysis, we obtained 14 mitochondrial protein genes (CKMT1B, CYP27A1, GPX1, GPX4, GRPEL2, HPDL, MALSU1, MRPS5, NDUFC1, OPA3, OXSM, POLRMT, SAMM50, TOMM40L) related to patient prognosis. Based on the expression levels of these 14 genes in each patient, we developed a new scoring algorithm. Compared with the traditional TNM classification system, the algorithm has better accuracy in predicting patient prognosis. Moreover, a nomogram was constructed through the combination of the scoring algorithm and the patient’s clinical features. Conclusions: The scoring algorithm based on mitochondrial gene expression can assist clinicians in predicting the postoperative survival rate of patients, allowing them to devise more precise treatment programs.

Emerging mitochondrial-mediated mechanisms involved in oligodendrocyte development.

Oligodendrocytes are the myelinating glia of the central nervous system and are generated after oligodendrocyte progenitor cells (OPCs) transition into pre-oligodendrocytes and then into myelinating oligodendrocytes. Myelin is essential for proper signal transmission within the nervous system and axonal metabolic support. Although the intrinsic and extrinsic factors that support the differentiation, survival, integration, and subsequent myelination of appropriate axons have been well investigated, little is known about how mitochondria-related pathways such as mitochondrial dynamics, bioenergetics, and apoptosis finely tune these developmental events. Previous findings suggest that changes to mitochondrial morphology act as an upstream regulatory mechanism of neural stem cell (NSC) fate decisions. Whether a similar mechanism is engaged during OPC differentiation has yet to be elucidated. Maintenance of mitochondrial dynamics is vital for regulating cellular bioenergetics, functional mitochondrial networks, and the ability of cells to distribute mitochondria to subcellular locations, such as the growing processes of oligodendrocytes. Myelination is an energy-consuming event, thus, understanding the interplay between mitochondrial dynamics, metabolism, and apoptosis will provide further insight into mechanisms that mediate oligodendrocyte development in healthy and disease states. Here we will provide a concise overview of oligodendrocyte development and discuss the potential contribution of mitochondrial mitochondrial-mediated mechanisms to oligodendrocyte bioenergetics and development.

Using a multiomics approach to unravel a septic shock specific signature in skeletal muscle

Sepsis is defined as a dysregulated host response to infection leading to organs failure. Among them, sepsis induces skeletal muscle (SM) alterations that contribute to acquired-weakness in critically ill patients. Proteomics and metabolomics could unravel biological mechanisms in sepsis-related organ dysfunction. Our objective was to characterize a distinctive signature of septic shock in human SM by using an integrative multi-omics approach. Muscle biopsies were obtained as part of a multicenter non-interventional prospective study. Study population included patients in septic shock (S group, with intra-abdominal source of sepsis) and two critically ill control populations: cardiogenic shock (C group) and brain dead (BD group). The proteins and metabolites were extracted and analyzed by High-Performance Liquid Chromatography-coupled to tandem Mass Spectrometry, respectively. Fifty patients were included, 19 for the S group (53% male, 64 ± 17 years, SAPS II 45 ± 14), 12 for the C group (75% male, 63 ± 4 years, SAPS II 43 ± 15), 19 for the BD group (63% male, 58 ± 10 years, SAPS II 58 ± 9). Biopsies were performed in median 3 days [interquartile range 1–4]) after intensive care unit admission. Respectively 31 patients and 40 patients were included in the proteomics and metabolomics analyses of 2264 proteins and 259 annotated metabolites. Enrichment analysis revealed that mitochondrial pathways were significantly decreased in the S group at protein level: oxidative phosphorylation (adjusted p = 0.008); branched chained amino acids degradation (adjusted p = 0.005); citrate cycle (adjusted p = 0.005); ketone body metabolism (adjusted p = 0.003) or fatty acid degradation (adjusted p = 0.008). Metabolic reprogramming was also suggested (i) by the differential abundance of the peroxisome proliferator-activated receptors signaling pathway (adjusted p = 0.007), and (ii) by the accumulation of fatty acids like octanedioic acid dimethyl or hydroxydecanoic. Increased polyamines and depletion of mitochondrial thioredoxin or mitochondrial peroxiredoxin indicated a high level of oxidative stress in the S group. Coordinated alterations in the proteomic and metabolomic profiles reveal a septic shock signature in SM, highlighting a global impairment of mitochondria-related metabolic pathways, the depletion of antioxidant capacities, and a metabolic shift towards lipid accumulation.ClinicalTrial registration: NCT02789995. Date of first registration 03/06/2016.

A glutathione-sensitive drug delivery system based on carboxymethyl chitosan co-deliver Rose Bengal and oxymatrine for combined cancer treatment

At present, monotherapy of tumor has not met the clinical needs, due to high doses, poor efficacy, and the emergence of drug resistance. Combination therapy can effectively solve these problems, which is a better option for tumor suppression. Based on this, we developed a novel glutathione-sensitive drug delivery nanoparticle system (OMT/CMCS-CYS-RB NPs) for oral cancer treatment. Briefly, carboxymethyl chitosan (CMCS) was used as a carrier to simultaneously load Rose Bengal (RB) and oxymatrine (OMT). The OMT/CMCS-CYS-RB NPs prepared by ion crosslinking were spheres with a stable structure. In addition, the nanoparticles can be excited in vitro to generate a large amount of singlet oxygen, which has a good photodynamic effect. In vitro anti-tumor activity study showed that the nanoparticles after the laser enhanced therapeutic efficacy on tumor cells compared with the free drug and exhibited well security. Furthermore, OMT/CMCS-CYS-RB NPs could inhibit the PI3K/AKT signaling pathway in oxidative stress, and realize tumor apoptosis through mitochondria-related pathways. In conclusion, this combination delivery system for delivering RB and OMT is a safe and effective strategy, which may provide a new avenue for the tumor treatment.

Desmin Knock-Out Cardiomyopathy: A Heart on the Verge of Metabolic Crisis.

Desmin mutations cause familial and sporadic cardiomyopathies. In addition to perturbing the contractile apparatus, both desmin deficiency and mutated desmin negatively impact mitochondria. Impaired myocardial metabolism secondary to mitochondrial defects could conceivably exacerbate cardiac contractile dysfunction. We performed metabolic myocardial phenotyping in left ventricular cardiac muscle tissue in desmin knock-out mice. Our analyses revealed decreased mitochondrial number, ultrastructural mitochondrial defects, and impaired mitochondria-related metabolic pathways including fatty acid transport, activation, and catabolism. Glucose transporter 1 and hexokinase-1 expression and hexokinase activity were increased. While mitochondrial creatine kinase expression was reduced, fetal creatine kinase expression was increased. Proteomic analysis revealed reduced expression of proteins involved in electron transport mainly of complexes I and II, oxidative phosphorylation, citrate cycle, beta-oxidation including auxiliary pathways, amino acid catabolism, and redox reactions and oxidative stress. Thus, desmin deficiency elicits a secondary cardiac mitochondriopathy with severely impaired oxidative phosphorylation and fatty and amino acid metabolism. Increased glucose utilization and fetal creatine kinase upregulation likely portray attempts to maintain myocardial energy supply. It may be prudent to avoid medications worsening mitochondrial function and other metabolic stressors. Therapeutic interventions for mitochondriopathies might also improve the metabolic condition in desmin deficient hearts.

A facile cell culture device for studying nuclear and mitochondrial response of endothelial cells to hydrostatic pressure

There is no clear consensus regarding how cells respond to hydrostatic pressure. This is largely attributable to the high heterogeneity among cell types and the diverse custom-made devices used in previous studies. The aim of this work was to develop a facile device that could mimic various pressure environments and then delineate the cellular response to pressure stimulus. The device described here achieved both stable and periodic pressurization without oxygen deprivation. The biological utility of the device was assessed using human umbilical vein endothelial cells. We found more stereoscopic nuclear morphology and re-distribution of lamin A/C under high hydrostatic pressure compared to control cells. Mass spectrometry-based proteomics analysis showed significant changes in mitochondria-related pathways. Western blot analysis confirmed that high hydrostatic pressure induced a tendency toward mitochondrial fusion. Increased mitochondrial activity was observed as well. In conclusion, this device can be readily applied in biological research and extend our understanding of cellular mechano-sensation and the associated changes in mitochondrial behaviors.

Systemic inflammation and metabolic disturbances underlie inpatient mortality among ill children with severe malnutrition.

Children admitted to hospital with an acute illness and concurrent severe malnutrition [complicated severe malnutrition (CSM)] have a high risk of dying. The biological processes underlying their mortality are poorly understood. In this case-control study nested within a multicenter randomized controlled trial among children with CSM in Kenya and Malawi, we found that blood metabolomic and proteomic profiles robustly differentiated children who died (n = 92) from those who survived (n = 92). Fatalities were characterized by increased energetic substrates (tricarboxylic acid cycle metabolites), microbial metabolites (e.g., propionate and isobutyrate), acute phase proteins (e.g., calprotectin and C-reactive protein), and inflammatory markers (e.g., interleukin-8 and tumor necrosis factor–α). These perturbations indicated disruptions in mitochondria-related bioenergetic pathways and sepsis-like responses. This study identified specific biomolecular disturbances associated with CSM mortality, revealing that systemic inflammation and bioenergetic deficits are targetable pathophysiological processes for improving survival of this vulnerable population.

Emerging Roles of COX7RP and Mitochondrial Oxidative Phosphorylation in Breast Cancer.

Metabolic alterations are critical events in cancers, which often contribute to tumor pathophysiology. While aerobic glycolysis is a known characteristic of cancer-related metabolism, recent studies have shed light on mitochondria-related metabolic pathways in cancer biology, including oxidative phosphorylation (OXPHOS), amino acid and lipid metabolism, nucleic acid metabolism, and redox regulation. Breast cancer is the most common cancer in women; thus, elucidation of breast cancer-related metabolic alteration will help to develop cancer drugs for many patients. We here aim to define the contribution of mitochondrial metabolism to breast cancer biology. The relevance of OXPHOS in breast cancer has been recently defined by the discovery of COX7RP, which promotes mitochondrial respiratory supercomplex assembly and glutamine metabolism: the latter is also shown to promote nucleic acid and fatty acid biosynthesis as well as ROS defense regulation. In this context, the estrogen-related receptor (ERR) family nuclear receptors and collaborating coactivators peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1) are essential transcriptional regulators for both energy production and cancer-related metabolism. Summarizing recent findings of mitochondrial metabolism in breast cancer, this review will aim to provide a clue for the development of alternative clinical management by modulating the activities of responsible molecules involved in disease-specific metabolic alterations.