Altered Mitochondrial Metabolism Research Articles

Antileukemic potential of methylated indolequinone MAC681 through immunogenic necroptosis and PARP1 degradation

BackgroundDespite advancements in chronic myeloid leukemia (CML) therapy with tyrosine kinase inhibitors (TKIs), resistance and intolerance remain significant challenges. Leukemia stem cells (LSCs) and TKI-resistant cells rely on altered mitochondrial metabolism and oxidative phosphorylation. Targeting rewired energy metabolism and inducing non-apoptotic cell death, along with the release of damage-associated molecular patterns (DAMPs), can enhance therapeutic strategies and immunogenic therapies against CML and prevent the emergence of TKI-resistant cells and LSC persistence.MethodsTranscriptomic analysis was conducted using datasets of CML patients' stem cells and healthy cells. DNA damage was evaluated by fluorescent microscopy and flow cytometry. Cell death was assessed by trypan blue exclusion test, fluorescent microscopy, flow cytometry, colony formation assay, and in vivo Zebrafish xenografts. Energy metabolism was determined by measuring NAD+ and NADH levels, ATP production rate by Seahorse analyzer, and intracellular ATP content. Mitochondrial fitness was estimated by measurements of mitochondrial membrane potential, ROS, and calcium accumulation by flow cytometry, and morphology was visualized by TEM. Bioinformatic analysis, real-time qPCR, western blotting, chemical reaction prediction, and molecular docking were utilized to identify the drug target. The immunogenic potential was assessed by high mobility group box (HMGB)1 ELISA assay, luciferase-based extracellular ATP assay, ectopic calreticulin expression by flow cytometry, and validated by phagocytosis assay, and in vivo vaccination assay using syngeneic C57BL/6 mice.ResultsTranscriptomic analysis identified metabolic alterations and DNA repair deficiency signatures in CML patients. CML patients exhibited enrichment in immune system, DNA repair, and metabolic pathways. The gene signature associated with BRCA mutated tumors was enriched in CML datasets, suggesting a deficiency in double-strand break repair pathways. Additionally, poly(ADP-ribose) polymerase (PARP)1 was significantly upregulated in CML patients’ stem cells compared to healthy counterparts. Consistent with the CML patient DNA repair signature, treatment with the methylated indolequinone MAC681 induced DNA damage, mitochondrial dysfunction, calcium homeostasis disruption, metabolic catastrophe, and necroptotic-like cell death. In parallel, MAC681 led to PARP1 degradation that was prevented by 3-aminobenzamide. MAC681-treated myeloid leukemia cells released DAMPs and demonstrated the potential to generate an immunogenic vaccine in C57BL/6 mice. MAC681 and asciminib exhibited synergistic effects in killing both imatinib-sensitive and -resistant CML, opening new therapeutic opportunities.ConclusionsOverall, increasing the tumor mutational burden by PARP1 degradation and mitochondrial deregulation makes CML suitable for immunotherapy.

Energy substrate supplementation increases ATP levels and is protective to PD neurons.

Alteration of mitochondrial metabolism by various mutations or toxins leads to various neurological conditions. Age-related changes in energy metabolism could also play the role of a trigger for neurodegenerative disorders. Nonetheless, it is not clear if restoration of ATP production or supplementation of brain cells with substrates for energy production could be neuroprotective. Using primary neurons and astrocytes, and neurons with familial forms of neurodegenerative disorders we studied whether various substrates of energy metabolism could improve mitochondrial metabolism and stimulate ATP production, and whether increased ATP levels could protect cells against glutamate excitotoxicity and neurodegeneration. We found that supplementation of neurons with several substrates, or combination thereof, for the TCA cycle and cellular respiration, and oxidative phosphorylation resulted in an increase in mitochondrial NADH level and in mitochondrial membrane potential and led to an increased level of ATP in neurons and astrocytes. Subsequently, these cells were protected against energy deprivation during ischemia or glutamate excitotoxicity. Provision of substrates for energy metabolism to cells with familial forms of Parkinson’s disease also prevented triggering of cell death. Thus, restoration of energy metabolism and increase of ATP production can play neuroprotective role in neurodegeneration. A combination of a succinate salt of choline and nicotinamide provided the best results.

Smoking cessation only partially reverses cardiac metabolic and structural remodeling in mice.

Active cigarette smoking is a major risk factor for chronic obstructive pulmonary disease that remains elevated after cessation. Skeletal muscle dysfunction has been well documented after smoking, but little is known about cardiac adaptations to cigarette smoking. The underlying cellular and molecular cardiac adaptations, independent of confounding lifestyle factors, and time course of reversibility by smoking cessation remain unclear. We hypothesized that smoking negatively affects cardiac metabolism and induces local inflammation in mice, which do not readily reverse upon 2-week smoking cessation. Mice were exposed to air or cigarette smoke for 14 weeks with or without 1- or 2-week smoke cessation. We measured cardiac mitochondrial respiration by high-resolution respirometry, cardiac mitochondrial density, abundance of mitochondrial supercomplexes by electrophoresis, and capillarization, fibrosis, and macrophage infiltration by immunohistology, and performed cardiac metabolome and lipidome analysis by mass spectrometry. Mitochondrial protein, supercomplex content, and respiration (all p < 0.03) were lower after smoking, which were largely reversed within 2-week smoking cessation. Metabolome and lipidome analyses revealed alterations in mitochondrial metabolism, a shift from fatty acid to glucose metabolism, which did not revert to control upon smoking cessation. Capillary density was not different after smoking but increased after smoking cessation (p = 0.02). Macrophage infiltration and fibrosis (p < 0.04) were higher after smoking but did not revert to control upon smoking cessation. While cigarette-impaired smoking-induced cardiac mitochondrial function was reversed by smoking cessation, the remaining fibrosis and macrophage infiltration may contribute to the increased risk of cardiovascular events after smoking cessation.

KDM5-mediated transcriptional activation of ribosomal protein genes alters translation efficiency to regulate mitochondrial metabolism in neurons.

Genes encoding the KDM5 family of transcriptional regulators are disrupted in individuals with intellectual disability (ID). To understand the link between KDM5 and ID, we characterized five Drosophila strains harboring missense alleles analogous to those observed in patients. These alleles disrupted neuroanatomical development, cognition and other behaviors, and displayed a transcriptional signature characterized by the downregulation of many ribosomal protein genes. A similar transcriptional profile was observed in KDM5C knockout iPSC-induced human glutamatergic neurons, suggesting an evolutionarily conserved role for KDM5 proteins in regulating this class of gene. In Drosophila, reducing KDM5 changed neuronal ribosome composition, lowered the translation efficiency of mRNAs required for mitochondrial function, and altered mitochondrial metabolism. These data highlight the cellular consequences of altered KDM5-regulated transcriptional programs that could contribute to cognitive and behavioral phenotypes. Moreover, they suggest that KDM5 may be part of a broader network of proteins that influence cognition by regulating protein synthesis.

Abstract 4425: Metabolic vulnerabilities of dedifferentiated liposarcoma

Abstract Dedifferentiated liposarcoma (DDLPS) is a rare, life-threatening malignancy in the family of adipocytic sarcomas. DDLPS, which usually arises in the retroperitoneum of middle-aged adults, has a poor prognosis. This is due to the propensity of DDLPS to metastasize and recur locally, combined with a dearth of effective systemic therapies. A longstanding curiosity is that DDLPS has non-lipogenic morphology and no lipid droplets, while its less aggressive sister sarcoma, well-differentiated liposarcoma (WDLPS), resembles benign adipose tissue and contains large lipid droplets. How DDLPS metabolizes lipids and the metabolic vulnerabilities of DDLPS in patients, which may form new therapeutic targets, are unknown. In our project, we investigate the metabolism of DDLPS versus WDLPS using patient samples and cell lines. Snap-frozen tissues from patients were obtained from the Dana-Farber/Harvard Cancer Center specimen bank of DDLPS and WDLPS. We performed metabolomics and lipidomics on these samples. We complemented these results with publicly available transcriptional profiles of separate cohorts of DDLPS, WDLPS, and other cancers. In vitro, we made use of a panel of multiple DDLPS-derived cell lines, WDLPS-derived cells, benign preadipocytes, and benign adipocytes. We measured mitochondrial function and the cellular effects of perturbing various metabolites in screens in culture. Overall, our initial results indicate strong alterations in mitochondrial metabolism in DDLPS in patients. In culture, DDLPS is susceptible to multiple metabolic perturbations related to mitochondrial dysfunction. These metabolic vulnerabilities of DDLPS provide potential therapeutic opportunities. Work is ongoing to optimize the targeting of these vulnerabilities in vivo, elucidate the molecular roles of specific metabolites, and complete a blueprint of DDLPS metabolic weaknesses in patients. Citation Format: Jamie O. Brett, Ji Seul Han, Choah Kim, Liam P. Kelley, SeongJun Han, Dylan Boone, Joseph Crowley, Shakchhi Joshi, Chandrajit P. Raut, Anna Greka, Marcia C. Haigis. Metabolic vulnerabilities of dedifferentiated liposarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4425.

Abstract 7059: Remodeling of anaplastic thyroid cancer metabolic signature by natural alkaloid berberine

Abstract Anaplastic thyroid cancer (ATC) is a rare, fatal cancer with a five-year survival of 4%. Universally diagnosed at stage IV, ATC is characterized by its lack of differentiation and metabolic dysregulation. Refractory to all established therapies, we propose natural alkaloid berberine (BBR) as a therapeutic with multitarget efficacy to alter mitochondrial metabolism and reprogram ATC’s aggressive phenotype. Assays used monocyte cell line U937, ATC cell lines T238 and SW1736, and immortalized normal thyroid cell line Nthy-ori-3-1. All assays used 100µM concentration of BBR or DMSO vehicle control for 24 hours for a tumoricidal effect. Validation of in vitro findings via RNA-Seq was conducted by Genewiz from Azenta and Qiagen’s Ingenuity Pathway Analysis was used for in silico modeling. Mitochondria were isolated via differential centrifugation. Modeling the ATC tumor microenvironment, U937 cells were activated and polarized into a proinflammatory macrophage phenotype. BBR treatment at the activation/polarization stages, 33 soluble inflammatory mediators were downregulated in the conditioned media compared to controls. In targeting the aggressiveness of anaplastic thyroid disease, BBR slowed proliferation by 80% selectively in ATC cells from 48 to 72 hours, while sparing normal cells. BBR reduced migratory capacity by 30% in ATC cells after 24, 48, and 72 hours and reduced migration and invasion by 30%. These observations were substantiated by Western blot analysis - BBR selectively decreased phosphorylation of MEK, ERK, and ribosomal protein S6, crucial downstream regulators of the pro-proliferative and pro-survival pathways in ATC cells. Further, BBR specifically modulated cancer-associated metabolism as observed through an increase in AMPKα phosphorylation, a major rate-limiting protein in cancer-induced dysregulation with an anti-tumor effect. Validation of in vitro findings via RNA-Seq revealed more than 400 significantly differentially expressed genes involved in mitochondrial metabolism, glycometabolism, sirtuin signaling, apoptosis, and proliferation. Following a comprehensive analysis, we identified significant downregulation of 25 of 37 total mitochondrially encoded genes (MTs) and 13 of 13 mitochondrially encoded protein-coding genes comprising the oxidative phosphorylation complexes illuminating a clear link between BBR treatment and altered mitochondrial metabolism in ATC. Additionally, protein expression of significantly downregulated mitochondrial genes identified via RNA Seq was validated via Western blot demonstrating decreased mitochondrially-encoded protein expression related to oxidative phosphorylation. This work reveals a novel role for BBR as an inhibitor of mitochondrial metabolism that can be used to reprogram the aggressive nature of ATC and open the door for promising combination therapy in the treatment of ATC. Citation Format: Tara Jarboe, Nicole R. DeSouza, Kaci Kopec, Jan Geliebter, Xiu-Min Li, Raj K. Tiwari. Remodeling of anaplastic thyroid cancer metabolic signature by natural alkaloid berberine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7059.

Mitochondrial Metabolism in Major Depressive Disorder: From Early Diagnosis to Emerging Treatment Options.

Major Depressive Disorder (MDD) is one of the most disabling diseases in the world. MDD is traditionally diagnosed based on a patient's symptoms, which can lead to misdiagnosis. Although the pathogenic mechanisms of MDD are unknown, several studies have identified mitochondrial dysfunction as a central factor in the onset and progression of MDD. In the context of MDD, alterations in mitochondrial metabolism can lead to imbalances in energy production and oxidative stress, contributing to the disorder´s underlying pathophysiological mechanisms. Consequently, the identification of mitochondrial dysfunction as a key biomarker for early and accurate diagnosis of MDD represents a significant challenge. Faced with the limits of traditional treatments with antidepressants, new pharmacological therapeutic targets are being investigated such as ketamine/esketamine, psychedelics, or anti-inflammatories. All of these drugs show potential antidepressant effects due to their speed of action and ability to modulate neuroplasticity and/or motor processing. In parallel, non-pharmacological therapeutic targets are studied, like Transcranial Magnetic Stimulation (TMS) and Deep Brain Stimulation (DBS), recognized for their ability to modulate neuronal activity and offer treatment alternatives. As cellular activity is directly related to mitochondrial respiration, the aim of this review is examining the link between mitochondrial dysfunction and MDD, assessing how mitochondrial biomarkers could provide a more objective and precise diagnostic tool, and exploring other treatments in addition to traditional antidepressants, with a specific focus on emerging therapeutic targets. Finally, a detailed analysis of the strengths, weaknesses, opportunities, and threats of these approaches was carried out, highlighting the key challenges that must be addressed.

Abstract A014: ClpP drives efficacy and mediates acquired resistance with imipridones ONC201 and ONC206 in glioma in vitro

Abstract A014: ClpP drives efficacy and mediates acquired resistance with imipridones ONC201 and ONC206 in glioma <i>in vitro</i>

Inhibitors of Rho/MRTF/SRF Transcription Pathway Regulate Mitochondrial Function.

RhoA-regulated gene transcription by serum response factor (SRF) and its transcriptional cofactor myocardin-related transcription factors (MRTFs) signaling pathway has emerged as a promising therapeutic target for pharmacological intervention in multiple diseases. Altered mitochondrial metabolism is one of the major hallmarks of cancer, therefore, this upregulation is a vulnerability that can be targeted with Rho/MRTF/SRF inhibitors. Recent advances identified a novel series of oxadiazole-thioether compounds that disrupt the SRF transcription, however, the direct molecular target of these compounds is unclear. Herein, we demonstrate the Rho/MRTF/SRF inhibition mechanism of CCG-203971 and CCG-232601 in normal cell lines of human lung fibroblasts and mouse myoblasts. Further studies investigated the role of these molecules in targeting mitochondrial function. We have shown that these molecules hyperacetylate histone H4K12 and H4K16 and regulate the genes involved in mitochondrial function and dynamics. These small molecule inhibitors regulate mitochondrial function as a compensatory mechanism by repressing oxidative phosphorylation and increasing glycolysis. Our data suggest that these CCG molecules are effective in inhibiting all the complexes of mitochondrial electron transport chains and further inducing oxidative stress. Therefore, our present findings highlight the therapeutic potential of CCG-203971 and CCG-232601, which may prove to be a promising approach to target aberrant bioenergetics.

Induction of a memory-like CD4+ T-cell phenotype by airway smooth muscle cells.

In asthma, CD4+ T-cell interaction with airway smooth muscle (ASM) may enhance its contractile properties and promote its proliferation. However, less is known about the effects of this interaction on T cells. To explore the consequences of interaction of CD4+ T cells with ASM we placed the cells in co-culture and analyzed the phenotypic and functional changes in the T cells. Effector status as well as cytokine expression was assessed by flow cytometry. An increase in CD45RA-CD45RO+ memory T cells was observed after co-culture; however, these cells were not more responsive to CD3/28 restimulation. A reduction in mitochondrial coupling and an increase in the production of mitochondrial reactive oxygen species by CD4+ T cells post-restimulation suggested altered mitochondrial metabolism after co-culture. RNA sequencing analysis of the T cells revealed characteristic downregulation of effector T-cell-associated genes, but a lack of upregulation of memory T-cell-associated genes. The results of this study demonstrate that ASM cells can induce a phenotypic shift in CD4+ T cells into memory-like T cells but with reduced capacity for activation.

DOP88 Lipids drive myofibroblast activation and the epithelial-mesenchymal transition process in Crohn’s Disease

Abstract Background Fibrostenosis represents one of the major clinical complications of Crohn’s Disease (CD). However, the molecular mechanisms underlying intestinal fibrogenesis remain poorly understood and anti-fibrotic therapy has not yet been developed. Growing evidences supports that oxidative stress and the epithelial-mesenchymal transition (EMT) process contribute to the development and progression of fibrosis. Here, we assessed the role of lipids in fibrogenesis and whether mitochondria dysfunction can support fibrosis formation. Methods Spatial metabolomics analysis and adipophilin (ADFP) staining were performed on surgical specimens from fibrotic ileum and the surrounding region (healthy) derived from CD patients. Fibroblasts isolated from fibrotic and healthy ileum and human induced pluripotent stem cell-derived intestinal organoids (iHOs) were treated for 1-3 weeks with lipid mix (2%) and analyzed by RNA sequencing. Pathways significantly modulated were validated by RT-PCR, WB, FACS analysis, and proliferative, migratory and contraction assays, and mitochondrial functions by Seahorse analyzer. Results Spatial metabolomics revealed a significant accumulation of lipids characterized by very long-chain fatty acids in the fibrotic area compared to surrounding healthy regions, which was further confirmed by ADFP staining. RNA-seq analysis showed overlapping dysregulated pathways between healthy fibroblasts stimulated with lipids and fibrotic fibroblasts, in particular genes related to cell cycle, cytoskeletal reorganization, migration, contractility and cell metabolism (oxidative stress) which were further confirmed by functional assays. Among the genes related to oxidative stress, lipid stimulation significantly decreased NFE2L2 and promoted an increase in CPT1A, gene encoding for a fatty oxidation mediator. Moreover, lipid-stimulated fibroblasts showed a reduction in mitochondrial respiration, particularly basal and maximal respiration, and spare respiratory capacity by Seahorse analysis. On the other hand, long exposure of iHOs to lipids promoted the EMT process through the upregulation of TWIST, ZEB, VIM, and S100a4. Conclusion Lipid stimulation induced myofibroblast activation through oxidative stress and alteration of mitochondrial metabolism, and increased the expression of EMT transcription factors in intestinal epithelial cells (iHOs) that may support fibroblast-mediated pro-fibrotic activity. These data indicate that regulators of fatty acid oxidation involved in the fibrotic process may represent new potential targets for the treatment of fibrostenotic CD patients.

Exploring Metabolic and Gut Microbiome Responses to Paraquat Administration in Male Wistar Rats: Implications for Oxidative Stress.

In this study, we examined the metabolic and gut microbiome responses to paraquat (PQ) in male Wistar rats, focusing on oxidative stress effects. Rats received a single intraperitoneal injection of PQ at 15 and 30 mg/kg, and various oxidative stress parameters (i.e., MDA, SOD, ROS, 8-isoprostanes) were assessed after three days. To explore the omic profile, GC-qTOF and UHPLC-qTOF were performed to assess the plasma metabolome; 1H-NMR was used to assess the urine metabolome; and shotgun metagenomics sequencing was performed to study the gut microbiome. Our results revealed reductions in body weight and tissue changes, particularly in the liver, were observed, suggesting a systemic effect of PQ. Elevated lipid peroxidation and reactive oxygen species levels in the liver and plasma indicated the induction of oxidative stress. Metabolic profiling revealed changes in the tricarboxylic acid cycle, accumulation of ketone body, and altered levels of key metabolites, such as 3-hydroxybutyric acid and serine, suggesting intricate links between energy metabolism and redox reactions. Plasma metabolomic analysis revealed alterations in mitochondrial metabolism, nicotinamide metabolism, and tryptophan degradation. The gut microbiome showed shifts, with higher PQ doses influencing microbial populations (e.g., Escherichia coli and Akkermansia muciniphila) and metagenomic functions (pyruvate metabolism, fermentation, nucleotide and amino acid biosynthesis). Overall, this study provides comprehensive insights into the complex interplay between PQ exposure, metabolic responses, and gut microbiome dynamics. These findings enhance our understanding of the mechanisms behind oxidative stress-induced metabolic alterations and underscore the connections between xenobiotic exposure, gut microbiota, and host metabolism.

Multiomic analysis in fibroblasts of patients with inborn errors of cobalamin metabolism reveals concordance with clinical and metabolic variability

The high variability in clinical and metabolic presentations of inborn errors of cobalamin (cbl) metabolism (IECM), such as the cblC/epicblC types with combined deficits in methylmalonyl-coA mutase (MUT) and methionine synthase (MS), are not well understood. They could be explained by the impaired expression/activity of enzymes from other metabolic pathways. We performed metabolomic, genomic, proteomic, and post-translational modification (PTM) analyses in fibroblasts from three cblC cases and one epi-cblC case compared with three cblG cases with specific MS deficits and control fibroblasts. CblC patients had metabolic profilings consistent with altered urea cycle, glycine, and energy mitochondrial metabolism. Metabolomic analysis showed partial disruption and increased glutamate/ketoglutarate anaplerotic pathway of the tricarboxylic acid cycle (TCA), in patient fibroblasts. RNA-seq analysis showed decreased expression of MT-TT (mitochondrial tRNA threonine), MT-TP (mitochondrial tRNA proline), OXCT1 (succinyl CoA:3-oxoacid CoA transferase deficiency), and MT-CO1 (cytochrome C oxidase subunit 1). Proteomic changes were observed for key mitochondrial enzymes, including NADH:ubiquinone oxidoreductase subunit A8 (NDUFA8), carnitine palmitoyltransferase 2 (CPT2), and ubiquinol-cytochrome C reductase, complex III subunit X (UQCR10). Propionaldehyde addition in ornithine aminotransferase was the predominant PTM in cblC cells and could be related with the dramatic cellular increase in propionate and methylglyoxalate. It is consistent with the decreased concentration of ornithine reported in 3 cblC cases. Whether the changes detected after multi-omic analyses underlies clinical features in cblC and cblG types of IECM, such as peripheral and central neuropathy, cardiomyopathy, pulmonary hypertension, development delay, remains to be investigated. The omics-related effects of IECM on other enzymes and metabolic pathways are consistent with the diversity and variability of their age-related metabolic and clinical manifestations. PTMs are expected to produce cumulative effects, which could explain the influence of age on neurological manifestations. French Agence Nationale de la Recherche (Projects PREDICTS and EpiGONE) and Inserm.

Exploiting nuclear-mitochondrial cross-talk in theranostics: Enhancing drug delivery and diagnostic precision

The dynamic interplay between nuclear and mitochondrial processes plays a pivotal role in cellular homeostasis and disease progression. Exploiting this nuclear-mitochondrial cross-talk has emerged as a promising avenue in the field of theranostics, offering enhanced drug delivery and diagnostic precision for a wide range of medical conditions, particularly cancer. This abstract provides a brief overview of the key concepts and recent advancements in this rapidly evolving field. Recent research has elucidated the significance of mitochondrial dysfunction in various diseases, including cancer. Mitochondria, often referred to as the “powerhouses” of the cell, not only regulate energy production but also contribute to critical processes such as apoptosis, ROS generation, and metabolic signaling. Dysregulation of these mitochondrial functions is frequently associated with disease pathogenesis. In theranostics, the targeted modulation of mitochondrial function holds great promise. Mitochondria-targeted drug delivery systems have been designed to selectively deliver therapeutic agents to these organelles, thereby mitigating mitochondrial dysfunction while minimizing off-target effects. This precise drug delivery enhances the therapeutic efficacy of anticancer drugs and reduces the risk of drug resistance. Moreover, the diagnostic potential of nuclear-mitochondrial cross-talk is being harnessed to develop novel biomarkers and imaging techniques. Mitochondrial DNA mutations and alterations in mitochondrial metabolism serve as valuable indicators of disease progression and drug responsiveness. Non-invasive imaging modalities, such as positron emission tomography (PET) and magnetic resonance imaging (MRI), have been employed to visualize mitochondrial activity and assess therapeutic outcomes.

Lncrna Rmrp Regulate Mitochondrial Function in Relapsed and Refractory Acute Myeloid Leukemia

Background: The prognosis of relapsed and refractory acute myeloid leukemia (R/R AML) is extremely poor, primarily due to the development of chemotherapy resistance during the treatment, which leads to its relapse and refractory disease. Extensive studies have established that various dysfunctions in the mitochondria of AML cells play a significant role in promoting chemotherapy resistance and the recurrence of the disease. In our previous investigation, we successfully demonstrated the substantial enrichment of the long non-coding RNA (lncRNA) RMRP in the mitochondria. However, the specific function of RMRP in the mitochondria of R/R AML remains unexplored. The objective of this project is to uncover the function of RMRP in R/R AML mitochondria, aiming to provide innovative insights and a theoretical foundation for surmounting chemotherapy resistance in R/R AML. Methods: In order to investigate the factors that play a crucial role in R/R AML, we employed mass spectrometry (MS) to conduct a screening of factors associated with AML chemoresistance. We utilized quantitative real-time polymerase chain reaction (RT-qPCR) to assess the expression of lncRNA RMRP in both newly diagnosed AML (ND AML) and R/R AML patients. Furthermore, we knocked down the RMRP expression level by transfection with siRNA-NC and siRNA-RMRP. Additionally, we analyzed the correlation between lncRNA RMRP and mitochondria. To explore the involvement of lncRNA RMRP in regulating mitochondrial function in R/R AML, we performed mitochondrial oxidative phosphorylation metabolic function assays subsequent to the inhibition of lncRNA RMRP. Moreover, Western blot analysis was employed to evaluate the relative protein expression levels in AML cell lines. Results: We enrolled 23 AML patients (ND AML, n=12; R/R AML, n=11), and the result of MS shows that R/R AML group expressed higher level of mitochondria related protein. The qPCR results showed that R/R AML had higher expression level of RMRP ( P&amp;lt;0.0001) and mitochondrial genome genes ( P&amp;lt;0.0001) than ND AML patients. The result of co-cultured of BMSCs and AML suggests that mitochondrial transmission of BMSCs to AML existed in AML patients with high RMRP expression level( P&amp;lt;0.0001). The Seahorse metabolomics results suggest that RMRP knock down attenuated Spare Respiratory Capacity ( P=0.01) and Maximal Respiration ( P=0.01), increased the Cytarabine and Doxorubicin sensitivity, and induced alterations in the mitochondrial CpG1 and CpG9 methylation. Knockdown of RMRP is also accompanied by a decrease in mtDNA copy number ( P=0.10, 0.42, and 0.0074, respectively for mtDNA gene MT-ND2, MT-ND3, and MT-CO1), and mitochondrial genome transcription. Under transmission electron microscope (TEM), mitochondria were engulfed by lysosomes in RMRP knockdown AML cells. And results of Western blot showed that the autophagy markers such as LC3B, BNIP3L/Nix, NDP52 was upregulated, and SQSTM1, Parkin was downregulated in RMRP knockdown AML cells, suggesting that RMRP may induce mitophagy through the BNIP3L/Nix pathway, PINK1/Parkin pathway, and NDP52 pathway. Conclusion: In R/R AML, RMRP increased chemotherapy resistance and RMRP high expression was associated with multiple mitochondrial function abnormalities, including altered mitochondrial metabolism, reduced mitophagy, and altered mtDNA epigenetics.

Targeting altered calcium homeostasis and uncoupling protein-2 promotes sensitivity in drug-resistant breast cancer cells.

Metastatic breast cancer has the highest mortality rate among women owing to its poor clinical outcomes. Metastatic tumors pose challenges for treatment through conventional surgery or radiotherapy because of their diverse organ localization and resistance to various cytotoxic agents. Chemoresistance is a significant obstacle to effective breast cancer treatment owing to cancer's heterogeneous nature. Abnormalities in intracellular calcium signaling, coupled with altered mitochondrial metabolism, play a significant role in facilitating drug resistance and contribute to therapy resistance. Uncoupling protein-2 (UCP2) is considered as a marker of chemoresistance and is believed to play a major role in promoting metabolic shifts and tumor metastasis. In this context, it is imperative to understand the roles of altered calcium signaling and metabolic switching in the development of chemotherapeutic resistance. This study investigates the roles of UCP2 and intracellular calcium signaling (Ca2+ ) in promoting chemoresistance against cisplatin. Additionally, we explored the effectiveness of combining genipin (GP, a compound that reverses UCP2-mediated chemoresistance) and thapsigargin (TG, a calcium signaling modulator) in treating highly metastatic breast cancers. Our findings indicate that both aberrant Ca2+ signaling and metabolic shifts in cancer cells contribute to developing drug-resistant phenotypes, and the combination treatment of GP and TG significantly enhances drug sensitivity in these cells. Collectively, our study underscores the potential of these drug combinations as an effective approach to overcome drug resistance in chemoresistant cancers.

Inter-organ crosstalk during development and progression of type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is characterized by tissue-specific insulin resistance and pancreatic β-cell dysfunction, which result from the interplay of local abnormalities within different tissues and systemic dysregulation of tissue crosstalk. The main local mechanisms comprise metabolic (lipid) signalling, altered mitochondrial metabolism with oxidative stress, endoplasmic reticulum stress and local inflammation. While the role of endocrine dysregulation in T2DM pathogenesis is well established, other forms of inter-organ crosstalk deserve closer investigation to better understand the multifactorial transition from normoglycaemia to hyperglycaemia. This narrative Review addresses the impact of certain tissue-specific messenger systems, such as metabolites, peptides and proteins and microRNAs, their secretion patterns and possible alternative transport mechanisms, such as extracellular vesicles (exosomes). The focus is on the effects of these messengers on distant organs during the development of T2DM and progression to its complications. Starting from the adipose tissue as a major organ relevant to T2DM pathophysiology, the discussion is expanded to other key tissues, such as skeletal muscle, liver, the endocrine pancreas and the intestine. Subsequently, this Review also sheds light on the potential of multimarker panels derived from these biomarkers and related multi-omics for the prediction of risk and progression of T2DM, novel diabetes mellitus subtypes and/or endotypes and T2DM-related complications.

Neural stem cell-derived exosomes promote mitochondrial biogenesis and restore abnormal protein distribution in a mouse model of Alzheimer's disease.

Abstract JOURNAL/nrgr/04.03/01300535-202407000-00040/figure1/v/2023-11-20T171125Z/r/image-tiff Mitochondrial dysfunction is a hallmark of Alzheimer's disease. We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of APP/PS1 mice. Because Alzheimer's disease affects the entire brain, further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole. Here, we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing, immunostaining, and lightsheet imaging to clarify their spatial distribution. Additionally, to clarify whether the sirtuin 1 (SIRT1)-related pathway plays a regulatory role in neural stem cell-derived exosomes interfering with mitochondrial functional changes, we generated a novel nervous system-SIRT1 conditional knockout APP/PS1 mouse model. Our findings demonstrate that neural stem cell-derived exosomes significantly increase SIRT1 levels, enhance the production of mitochondrial biogenesis-related factors, and inhibit astrocyte activation, but do not suppress amyloid-β production. Thus, neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer's disease that activates the SIRT1-PGC1α signaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis. In addition, we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer's disease, and that neural stem cell-derived exosome treatment can reverse this effect, indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis.

Biofactors regulating mitochondrial function and dynamics in podocytes and podocytopathies.

Podocytes are terminally differentiated kidney cells acting as the main gatekeepers of the glomerular filtration barrier; hence, inhibiting proteinuria. Podocytopathies are classified as kidney diseases caused by podocyte damage. Different genetic and environmental risk factors can cause podocyte damage and death. Recent evidence shows that mitochondrial dysfunction also contributes to podocyte damage. Understanding alterations in mitochondrial metabolism and function in podocytopathies and whether altered mitochondrial homeostasis/dynamics is a cause or effect of podocyte damage are issues that need in-depth studies. This review highlights the roles of mitochondria and their bioenergetics in podocytes. Then, factors/signalings that regulate mitochondria in podocytes are discussed. After that, the role of mitochondrial dysfunction is reviewed in podocyte injury and the development of different podocytopathies. Finally, the mitochondrial therapeutic targets are considered.

Recent progress in understanding mitokines as diagnostic and therapeutic targets in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most prevalent tumors worldwide and the leading contributor to cancer-related deaths. The progression and metastasis of HCC are closely associated with altered mitochondrial metabolism, including mitochondrial stress response. Mitokines, soluble proteins produced and secreted in response to mitochondrial stress, play an essential immunomodulatory role. Immunotherapy has emerged as a crucial treatment option for HCC. However, a positive response to therapy is typically dependent on the interaction of tumor cells with immune regulation within the tumor microenvironment. Therefore, exploring the specific immunomodulatory mechanisms of mitokines in HCC is essential for improving the efficacy of immunotherapy. This study provides a comprehensive overview of the association between HCC and the immune microenvironment and highlights recent progress in understanding the involvement of mitochondrial function in preserving liver function. In addition, a systematic review of mitokines-mediated immunomodulation in HCC is presented. Finally, the potential diagnostic and therapeutic roles of mitokines in HCC are prospected and summarized. Recent progress in mitokine research represents a new prospect for mitochondrial therapy. Considering the potential of mitokines to regulate immune function, investigating them as a relevant molecular target holds great promise for the diagnosis and treatment of HCC.