bims-mitrat 2024-06-30 papers

bims-mitrat

Biomed News

on Mitochondrial transplantation and transfer

Issue of 2024–06–30
eleven papers selected by
Gökhan Burçin Kubat, Gulhane Health Sciences Institute

Extracellular Vesicle- and Mitochondria-Based Targeting of Non-Small Cell Lung Cancer Response to Radiation: Challenges and Perspectives.
Cellular communication through extracellular vesicles and lipid droplets.
Regulation of blood-brain barrier integrity by Dmp1-expressing astrocytes through mitochondrial transfer.
Mitochondrial puzzle in muscle: Linking the electron transport system to overweight.
Mitochondrial transfer of α-synuclein mediates carbon disulfide-induced mitochondrial dysfunction and neurotoxicity.
CRISPR delivery with extracellular vesicles: Promises and challenges.
Targeting extracellular vesicle delivery to the lungs by microgel encapsulation.
Aerobic exercise suppresses CCN2 secretion from senescent muscle stem cells and boosts muscle regeneration in aged mice.
Single-Mitochondrion Sequencing Uncovers Distinct Mutational Patterns and Heteroplasmy Landscape in Mouse Astrocytes and Neurons.
ISOLATION OF A PERSISTENTLY QUIESCENT MUSCLE SATELLITE CELL POPULATION.
The extracellular matrix integrates mitochondrial homeostasis.

Cancers (Basel). 2024 Jun 15. pii: 2235. [Epub ahead of print]16(12):

Extracellular Vesicle- and Mitochondria-Based Targeting of Non-Small Cell Lung Cancer Response to Radiation: Challenges and Perspectives.

Sergey Leonov, Anna Dorfman, Elizaveta Pershikova, Olumide Inyang, Lina Alhaddad, Yuzhe Wang, Margarita Pustovalova, Yulia Merkher.

  During the cell life cycle, extracellular vesicles (EVs) transport different cargos, including organelles, proteins, RNAs, DNAs, metabolites, etc., that influence cell proliferation and apoptosis in recipient cells. EVs from metastatic cancer cells remodel the extracellular matrix and cells of the tumor microenvironment (TME), promoting tumor invasion and metastatic niche preparation. Although the process is not fully understood, evidence suggests that EVs facilitate genetic material transfer between cells. In the context of NSCLC, EVs can mediate intercellular mitochondrial (Mt) transfer, delivering mitochondria organelle (MtO), mitochondrial DNA (mtDNA), and/or mtRNA/proteinaceous cargo signatures (MtS) through different mechanisms. On the other hand, certain populations of cancer cells can hijack the MtO from TME cells mainly by using tunneling nanotubes (TNTs). This transfer aids in restoring mitochondrial function, benefiting benign cells with impaired metabolism and enabling restoration of their metabolic activity. However, the impact of transferring mitochondria versus transplanting intact mitochondrial organelles in cancer remains uncertain and the subject of debate. Some studies suggest that EV-mediated mitochondria delivery to cancer cells can impact how cancer responds to radiation. It might make the cancer more resistant or more sensitive to radiation. In our review, we aimed to point out the current controversy surrounding experimental data and to highlight new paradigm-shifting modalities in radiation therapy that could potentially overcome cancer resistance mechanisms in NSCLC.

Keywords:  FLASH therapy; endocytosis; extracellular vesicles; metastasis; mitochondria transfer; pulsed high-power microwave radiation; radioresistance; radiosensitivity

DOI:  https://doi.org/10.3390/cancers16122235
J Extracell Biol. 2023 Mar;2(3): e77

Cellular communication through extracellular vesicles and lipid droplets.

Irumi Amarasinghe, William Phillips, Andrew F Hill, Lesley Cheng, Karla J Helbig, Eduard Willms, Ebony A Monson.

  Cellular communication is essential for effective coordination of biological processes. One major form of intercellular communication occurs via the release of extracellular vesicles (EVs). These vesicles mediate intercellular communication through the transfer of their cargo and are actively explored for their role in various diseases and their potential therapeutic and diagnostic applications. Conversely, lipid droplets (LDs) are vesicles that transfer cargo within cells. Lipid droplets play roles in various diseases and evidence for their ability to transfer cargo between cells is emerging. To date, there has been little interdisciplinary research looking at the similarities and interactions between these two classes of small lipid vesicles. This review will compare the commonalities and differences between EVs and LDs including their biogenesis and secretion, isolation and characterisation methodologies, composition, and general heterogeneity and discuss challenges and opportunities in both fields.

Keywords:  cellular communication; extracellular vesicles; lipid droplets

DOI:  https://doi.org/10.1002/jex2.77
Sci Adv. 2024 Jun 28. 10(26): eadk2913

Regulation of blood-brain barrier integrity by Dmp1-expressing astrocytes through mitochondrial transfer.

Delin Liu, Peng Liao, Hao Li, Sihan Tong, Bingqi Wang, Yafei Lu, Youshui Gao, Yigang Huang, Hao Zhou, Linjing Shi, John Papadimitriou, Yao Zong, Jun Yuan, Peilin Chen, Ziming Chen, Peng Ding, Yongqiang Zheng, Changqing Zhang, Minghao Zheng, Junjie Gao.

The blood-brain barrier (BBB) acts as the crucial physical filtration structure in the central nervous system. Here, we investigate the role of a specific subset of astrocytes in the regulation of BBB integrity. We showed that Dmp1-expressing astrocytes transfer mitochondria to endothelial cells via their endfeet for maintaining BBB integrity. Deletion of the Mitofusin 2 (Mfn2) gene in Dmp1-expressing astrocytes inhibited the mitochondrial transfer and caused BBB leakage. In addition, the decrease of MFN2 in astrocytes contributes to the age-associated reduction of mitochondrial transfer efficiency and thus compromises the integrity of BBB. Together, we describe a mechanism in which astrocytes regulate BBB integrity through mitochondrial transfer. Our findings provide innnovative insights into the cellular framework that underpins the progressive breakdown of BBB associated with aging and disease.

DOI: https://doi.org/10.1126/sciadv.adk2913
Obes Rev. 2024 Jun 24. e13794

Mitochondrial puzzle in muscle: Linking the electron transport system to overweight.

Rafael A Casuso.

  Human skeletal muscle mitochondria regulate energy expenditure. Research has shown that the functionality of muscle mitochondria is altered in subjects with overweight, as well as in response to nutrient excess and calorie restriction. Two metabolic features of obesity and overweight are (1) incomplete muscular fatty acid oxidation and (2) increased circulating lactate levels. In this study, I propose that these metabolic disturbances may originate from a common source within the muscle mitochondrial electron transport system. Specifically, a reorganization of the supramolecular structure of the electron transport chain could facilitate the maintenance of readily accessible coenzyme Q pools, which are essential for metabolizing lipid substrates. This approach is expected to maintain effective electron transfer, provided that there is sufficient complex III to support the Q-cycle. Such an adaptation could enhance fatty acid oxidation and prevent mitochondrial overload, thereby reducing lactate production. These insights advance our understanding of the molecular mechanisms underpinning metabolic dysregulation in overweight states. This provides a basis for targeted interventions in the quest for metabolic health.

Keywords:  coenzyme Q; electron transport chain; metabolism; obesity; respiratory supercomplexes; skeletal muscle

DOI:  https://doi.org/10.1111/obr.13794
Ecotoxicol Environ Saf. 2024 Jun 21. pii: S0147-6513(24)00689-4. [Epub ahead of print]281 116613

Mitochondrial transfer of α-synuclein mediates carbon disulfide-induced mitochondrial dysfunction and neurotoxicity.

Zhidan Liu, Shulin Shan, Kang Kang, Shuai Wang, Hui Yong, Yanan Sun, Yao Bai, Fuyong Song.

  Exposure to carbon disulfide (CS2) is a recognized risk factor in the pathogenesis of Parkinson's disease, yet the underlying mechanisms of deleterious effects on mitochondrial integrity have remained elusive. Here, through establishing CS2 exposure models in rat and SH-SY5Y cells, we demonstrated that highly expressed α-synuclein (α-Syn) is transferred to mitochondria via membrane proteins such as Tom20 and leads to mitochondrial dysfunction and mitochondrial oxidative stress, which ultimately causes neuronal injury. We first found significant mitochondrial damage and oxidative stress in CS2-exposed rat midbrain and SH-SY5Y cells and showed that mitochondrial oxidative stress was the main factor of mitochondrial damage by Mitoquinone intervention. Further experiments revealed that CS2 exposure led to the accumulation of α-Syn in mitochondria and that α-Syn co-immunoprecipitated with mitochondrial membrane proteins. Finally, the use of an α-Syn inhibitor (ELN484228) and small interfering RNA (siRNA) effectively mitigated the accumulation of α-Syn in neurons, as well as the inhibition of mitochondrial membrane potential, caused by CS2 exposure. In conclusion, our study identifies the translocation of α-Syn to mitochondria and the impairment of mitochondrial function, which has important implications for the broader understanding and treatment of neurodegenerative diseases associated with environmental toxins.

Keywords:  Carbon disulfide; Mitochondrial; Neurotoxicity; Oxidative stress; α-synuclein

DOI:  https://doi.org/10.1016/j.ecoenv.2024.116613
J Extracell Biol. 2023 Sep;2(9): e111

CRISPR delivery with extracellular vesicles: Promises and challenges.

Anne Højberg Berggreen, Julie Lund Petersen, Lin Lin, Karim Benabdellah, Yonglun Luo.

  The CRISPR gene editing tool holds great potential for curing genetic disorders. However, the safe, efficient, and specific delivery of the CRISPR/Cas9 components into cells and tissues remains a challenge. While many currently available delivery methods achieve high levels of gene editing effects in vivo, they often result in genotoxicity and immunogenicity. Extracellular vesicles (EVs), which are cell-derived lipid nanoparticles, are capable of transferring protein and nucleic acid cargoes between cells, making them a promising endogenous alternative to synthetic delivery methods. This review provides a comprehensive analysis of the currently available strategies for EV-mediated delivery of CRISPR/Cas9. These strategies include cell-based, passive loading obtained by overexpression of CRISPR/Cas9, active loading involving protein or RNA dimerization, and loading into already purified EVs. All these approaches suggest that EV-based CRISPR/Cas9 delivery is useful for achieving both in vitro and in vivo gene editing. Despite that, substantial variations in cellular uptake and gene editing efficiencies indicate that further improvement and standardization are required for the therapeutic use of EVs as a CRISPR/Cas9 delivery vehicle. These improvements include, but is not limited to, the high-yield purification of EVs, increased loading and release efficiencies, as well as improved tissue- or cell-specific targeting specificities.

Keywords:  CRISPR; Cas9; LNP; exosome; extracellular vesicles; gene editing; gene therapy

DOI:  https://doi.org/10.1002/jex2.111
J Extracell Biol. 2023 Jun;2(6): e94

Targeting extracellular vesicle delivery to the lungs by microgel encapsulation.

Nicholas D Cober, Katelynn Rowe, Yupu Deng, Ainara Benavente-Babace, David W Courtman, Michel Godin, Duncan J Stewart.

  Extracellular vesicles (EVs) secreted by stem and progenitor cells have significant potential as cell-free 'cellular' therapeutics. Yet, small EVs (<200 nm) are rapidly cleared after systemic administration, mainly by the liver, presenting challenges targeting EVs to a specific organ or tissue. Microencapsulation using natural nano-porous hydrogels (microgels) has been shown to enhance engraftment and increase the survival of transplanted cells. We sought to encapsulate EVs within microgels to target their delivery to the lung by virtue of their size-based retention within the pulmonary microcirculation. Mesenchymal stromal cell (MSC) derived EVs were labelled with the lipophilic dye (DiR) and encapsulated within agarose-gelatin microgels. Endothelial cells and bone marrow derived macrophages were able to take up EVs encapsulated in microgels in vitro, but less efficiently than the uptake of free EVs. Following intrajugular administration, microgel encapsulated EVs were selectively retained within the lungs for 72h, while free EVs were rapidly cleared by the liver. Furthermore, microgel-loaded EVs demonstrated greater uptake by lung cells, in particular CD45+ immune cells, as assessed by flow cytometry compared to free EVs. Microencapsulation of EVs may be a novel tool for enhancing the targeted delivery of EVs for future therapeutic applications.

Keywords:  biodistribution; biomaterials; extracellular vesicles; microencapsulation; pulmonary circulation

DOI:  https://doi.org/10.1002/jex2.94
J Cachexia Sarcopenia Muscle. 2024 Jun 26.

Aerobic exercise suppresses CCN2 secretion from senescent muscle stem cells and boosts muscle regeneration in aged mice.

Fan Li, Fulong Zhang, Haiwang Shi, Honglin Xia, Xiaobei Wei, Siqi Liu, Tao Wu, Yuecheng Li, Feng Shu, Mengjie Chen, Jie Li, Rui Duan.

   BACKGROUND: Aging negatively impacts tissue repair, particularly in skeletal muscle, where the regenerative capacity of muscle stem cells (MuSCs) diminishes with age. Although aerobic exercise is known to attenuate skeletal muscle atrophy, its specific impact on the regenerative and repair capacity of MuSCs remains unclear.
METHODS: Mice underwent moderate-intensity continuous training (MICT) from 9 months (aged + Ex-9M) or 20 months (aged + Ex-20M) to 25 months, with age-matched (aged) and adult controls. Histological examinations and MuSC transplantation assays assessed aerobic exercise effects on MuSC function and muscle regeneration. CCN2/connective tissue growth factor modulation (overexpression and knockdown) in MuSCs and AICAR supplementation effects were explored.
RESULTS: Aged mice displayed significantly reduced running duration (65.33 ± 4.32 vs. 161.9 ± 1.29 min, mean ± SD, P < 0.001) and distance (659.17 ± 103.64 vs. 3058.28 ± 46.26 m, P < 0.001) compared with adults. This reduction was accompanied by skeletal muscle weight loss and decreased myofiber cross-sectional area (CSA). However, MICT initiated at 9 or 20 months led to a marked increase in running duration (142.75 ± 3.14 and 133.86 ± 20.47 min, respectively, P < 0.001 compared with aged mice) and distance (2347.58 ± 145.11 and 2263 ± 643.87 m, respectively, P < 0.001). Additionally, MICT resulted in increased skeletal muscle weight and enhanced CSA. In a muscle injury model, aged mice exhibited fewer central nuclear fibres (CNFs; 266.35 ± 68.66/mm2), while adult, aged + Ex-9M and aged + Ex-20M groups showed significantly higher CNF counts (610.82 ± 46.76, 513.42 ± 47.19 and 548.29 ± 71.82/mm2, respectively; P < 0.001 compared with aged mice). MuSCs isolated from aged mice displayed increased CCN2 expression, which was effectively suppressed by MICT. Transplantation of MuSCs overexpressing CCN2 (Lenti-CCN2, Lenti-CON as control) into injured tibialis anterior muscle compromised regeneration capacity, resulting in significantly fewer CNFs in the Lenti-CCN2 group compared with Lenti-CON (488.07 ± 27.63 vs. 173.99 ± 14.28/mm2, P < 0.001) at 7 days post-injury (dpi). Conversely, knockdown of CCN2 (Lenti-CCN2shR, Lenti-NegsiR as control) in aged MuSCs improved regeneration capacity, significantly increasing the CNF count from 254.5 ± 26.36 to 560.39 ± 48.71/mm2. Lenti-CCN2 MuSCs also increased fibroblast proliferation and exacerbated skeletal muscle fibrosis, while knockdown of CCN2 in aged MuSCs mitigated this pattern. AICAR supplementation, mimicking exercise, replicated the beneficial effects of aerobic exercise by mitigating muscle weight decline, enhancing satellite cell activity and reducing fibrosis.
CONCLUSIONS: Aerobic exercise effectively reverses the decline in endurance capacity and mitigates muscle atrophy in aged mice. It inhibits CCN2 secretion from senescent MuSCs, thereby enhancing skeletal muscle regeneration and preventing fibrosis in aged mice. AICAR supplementation mimics the beneficial effects of aerobic exercise.

Keywords:  CCN2; MuSCs; aerobic exercise; aging; fibrosis; skeletal muscle

DOI:  https://doi.org/10.1002/jcsm.13526
bioRxiv. 2024 Jun 19. pii: 2024.06.13.598906. [Epub ahead of print]

Single-Mitochondrion Sequencing Uncovers Distinct Mutational Patterns and Heteroplasmy Landscape in Mouse Astrocytes and Neurons.

Parnika S Kadam, Zijian Yang, Youtao Lu, Hua Zhu, Yasemin Atiyas, Nishal Shah, Stephen Fisher, Erik Nordgren, Junhyong Kim, David Issadore, James Eberwine.

Background: Mitochondrial (mt) heteroplasmy can cause adverse biological consequences when deleterious mtDNA mutations accumulate disrupting 'normal' mt-driven processes and cellular functions. To investigate the heteroplasmy of such mtDNA changes we developed a moderate throughput mt isolation procedure to quantify the mt single-nucleotide variant (SNV) landscape in individual mouse neurons and astrocytes In this study we amplified mt-genomes from 1,645 single mitochondria (mts) isolated from mouse single astrocytes and neurons to 1. determine the distribution and proportion of mt-SNVs as well as mutation pattern in specific target regions across the mt-genome, 2. assess differences in mtDNA SNVs between neurons and astrocytes, and 3. Study cosegregation of variants in the mouse mtDNA.
Results: 1. The data show that specific sites of the mt-genome are permissive to SNV presentation while others appear to be under stringent purifying selection. Nested hierarchical analysis at the levels of mitochondrion, cell, and mouse reveals distinct patterns of inter- and intra-cellular variation for mt-SNVs at different sites. 2. Further, differences in the SNV incidence were observed between mouse neurons and astrocytes for two mt-SNV 9027:G>A and 9419:C>T showing variation in the mutational propensity between these cell types. Purifying selection was observed in neurons as shown by the Ka/Ks statistic, suggesting that neurons are under stronger evolutionary constraint as compared to astrocytes. 3. Intriguingly, these data show strong linkage between the SNV sites at nucleotide positions 9027 and 9461. f.
Conclusion: This study suggests that segregation as well as clonal expansion of mt-SNVs is specific to individual genomic loci, which is important foundational data in understanding of heteroplasmy and disease thresholds for mutation of pathogenic variants.

DOI: https://doi.org/10.1101/2024.06.13.598906
Am J Physiol Cell Physiol. 2024 Jun 24.

ISOLATION OF A PERSISTENTLY QUIESCENT MUSCLE SATELLITE CELL POPULATION.

Alexandra P Steele, Anika L Syroid, Cassandra Mombo, Shathana Raveetharan, Irena A Rebalka, Thomas J Hawke.

  While studies have identified characteristics of quiescent satellite cells, their isolation has been hampered by the fact that the isolation procedures result in the activation of these cells into their rapidly proliferating progeny (myoblasts). Thus, the use of myoblasts for therapeutic (regenerative medicine) or industrial applications (cellular agriculture) has been impeded by the limited proliferative and differentiative capacity of these myogenic progenitors. Here we identify a subpopulation of satellite cells isolated from mouse skeletal muscle using flow cytometry that are highly Pax7-positive, exhibit a very slow proliferation rate (7.7 ± 1.2 days/doubling), and are capable of being maintained in culture for at least three months without a change in phenotype. These cells can be activated from quiescence using a p38 inhibitor or by exposure to freeze-thaw cycles. Once activated, these cells proliferate rapidly (22.7 ± 0.2 hours/doubling), have reduced Pax7 expression (3-fold decrease in Pax7 fluorescence vs. quiescence) and differentiate into myotubes with a high efficiency. Furthermore, these cells withstand freeze-thawing readily without a significant loss of viability (83.1 ± 2.1% live). The results presented here provide researchers with a method to isolate quiescent satellite cells, allowing for more detailed examinations of the factors affecting satellite cell quiescence/activation and providing a cell source that has a unique potential in the regenerative medicine and cellular agriculture fields.

Keywords:  CD34; NCAM; Pax7; methodology; quiescent satellite cell

DOI:  https://doi.org/10.1152/ajpcell.00231.2024
Cell. 2024 Jun 24. pii: S0092-8674(24)00638-X. [Epub ahead of print]

The extracellular matrix integrates mitochondrial homeostasis.

Hanlin Zhang, C Kimberly Tsui, Gilberto Garcia, Larry K Joe, Haolun Wu, Ayane Maruichi, Wudi Fan, Sentibel Pandovski, Peter H Yoon, Brant M Webster, Jenni Durieux, Phillip A Frankino, Ryo Higuchi-Sanabria, Andrew Dillin.

  Cellular homeostasis is intricately influenced by stimuli from the microenvironment, including signaling molecules, metabolites, and pathogens. Functioning as a signaling hub within the cell, mitochondria integrate information from various intracellular compartments to regulate cellular signaling and metabolism. Multiple studies have shown that mitochondria may respond to various extracellular signaling events. However, it is less clear how changes in the extracellular matrix (ECM) can impact mitochondrial homeostasis to regulate animal physiology. We find that ECM remodeling alters mitochondrial homeostasis in an evolutionarily conserved manner. Mechanistically, ECM remodeling triggers a TGF-β response to induce mitochondrial fission and the unfolded protein response of the mitochondria (UPRMT). At the organismal level, ECM remodeling promotes defense of animals against pathogens through enhanced mitochondrial stress responses. We postulate that this ECM-mitochondria crosstalk represents an ancient immune pathway, which detects infection- or mechanical-stress-induced ECM damage, thereby initiating adaptive mitochondria-based immune and metabolic responses.

Keywords:  TGF-β; TMEM2; extracellular matrix; hyaluronan; immunity; mitochondria

DOI:  https://doi.org/10.1016/j.cell.2024.05.057