bims-mitmed 2024-07-21 papers

bims-mitmed

Biomed News

on Mitochondrial medicine

Issue of 2024‒07‒21
24 papers selected by
Dario Brunetti, Fondazione IRCCS Istituto Neurologico

The human mitochondrial mRNA structurome reveals mechanisms of gene expression.
ATAD1 prevents clogging of TOM and damage caused by un-imported mitochondrial proteins.
Supernumerary proteins of the human mitochondrial ribosomal small subunit are integral for assembly and translation.
Protocol for evaluating mitochondrial respiration in iPSC-derived neurons by the Seahorse XF analyzer.
Variability of Clinical Phenotypes Caused by Isolated Defects of Mitochondrial ATP Synthase (Review).
Anatomical and functional analysis of the corticospinal tract in an FRDA mouse model.
Chimeric Cell Therapy Transfers Healthy Donor Mitochondria in Duchenne Muscular Dystrophy.
Extracellular vesicles meet mitochondria: Potential roles in regenerative medicine.
Adenine base editing-mediated exon skipping restores dystrophin in humanized Duchenne mouse model.
Synaptic mitochondria glycation contributes to mitochondrial stress and cognitive dysfunction.
Mfn2-dependent fusion pathway of PE-enriched micron-sized vesicles.
Mitophagy-related regulated cell death: molecular mechanisms and disease implications.
The actin binding protein profilin 1 localizes inside mitochondria and is critical for their function.
Novel Insights into Parkin-Mediated Mitochondrial Dysfunction and "Mito-Inflammation" in α-Synuclein Toxicity. The Role of the cGAS-STING Signalling Pathway.
Single-cell multiomics reveals ENL mutation perturbs kidney developmental trajectory by rewiring gene regulatory landscape.
Mitochondrial perturbations in low-protein-diet-fed mice are associated with altered neutrophil development and effector functions.
HTR1B regulates mitochondrial homeostasis and mitophagy by activating the ERK/ MAPK signalling pathway during human embryonic arrest.
Early human fetal lung atlas reveals the temporal dynamics of epithelial cell plasticity.
Mitochondrial regulation of adult hippocampal neurogenesis: Insights into neurological function and neurodevelopmental disorders.
Mitotherapy with Fresh Isolated Cardiac Mitochondria Via Injection Into Blood Reduces Aluminum Phosphide-Induced Mortality and Protects Cardiac Tissue Against Oxidative Stress and Mitochondrial Damages.
Prenatal immune activation in mice induces long-term alterations in brain mitochondrial function.
Isolation, Culture, and Phenotypic Analysis of Murine Lung Organoids.
Interdisciplinary fetal-neonatal neurology training improves brain health across the lifespan.
In utero adeno-associated virus (AAV)-mediated gene delivery targeting sensory and supporting cells in the embryonic mouse inner ear.

Science. 2024 Jul 19. 385(6706): eadm9238

The human mitochondrial mRNA structurome reveals mechanisms of gene expression.

J Conor Moran, Amir Brivanlou, Michele Brischigliaro, Flavia Fontanesi, Silvi Rouskin, Antoni Barrientos.

The human mitochondrial genome encodes crucial oxidative phosphorylation system proteins, pivotal for aerobic energy transduction. They are translated from nine monocistronic and two bicistronic transcripts whose native structures remain unexplored, posing a gap in understanding mitochondrial gene expression. In this work, we devised the mitochondrial dimethyl sulfate mutational profiling with sequencing (mitoDMS-MaPseq) method and applied detection of RNA folding ensembles using expectation-maximization (DREEM) clustering to unravel the native mitochondrial messenger RNA (mt-mRNA) structurome in wild-type (WT) and leucine-rich pentatricopeptide repeat-containing protein (LRPPRC)-deficient cells. Our findings elucidate LRPPRC's role as a holdase contributing to maintaining mt-mRNA folding and efficient translation. mt-mRNA structural insights in WT mitochondria, coupled with metabolic labeling, unveil potential mRNA-programmed translational pausing and a distinct programmed ribosomal frameshifting mechanism. Our data define a critical layer of mitochondrial gene expression regulation. These mt-mRNA folding maps provide a reference for studying mt-mRNA structures in diverse physiological and pathological contexts.

DOI: https://doi.org/10.1126/science.adm9238
Cell Rep. 2024 Jul 17. pii: S2211-1247(24)00802-7. [Epub ahead of print]43(8): 114473

ATAD1 prevents clogging of TOM and damage caused by un-imported mitochondrial proteins.

John Kim, Madeleine Goldstein, Lauren Zecchel, Ryan Ghorayeb, Christopher A Maxwell, Hilla Weidberg.

  Mitochondria require the constant import of nuclear-encoded proteins for proper functioning. Impaired protein import not only depletes mitochondria of essential factors but also leads to toxic accumulation of un-imported proteins outside the organelle. Here, we investigate the consequences of impaired mitochondrial protein import in human cells. We demonstrate that un-imported proteins can clog the mitochondrial translocase of the outer membrane (TOM). ATAD1, a mitochondrial ATPase, removes clogged proteins from TOM to clear the entry gate into the mitochondria. ATAD1 interacts with both TOM and stalled proteins, and its knockout results in extensive accumulation of mitochondrial precursors as well as decreased protein import. Increased ATAD1 expression contributes to improved fitness of cells with inefficient mitochondrial protein import. Overall, we demonstrate the importance of the ATAD1 quality control pathway in surveilling protein import and its contribution to cellular health.

Keywords:  AAA ATPase; ATAD1; CP: Cell biology; CP: Metabolism; TOM clogging; mitochondrial protein import; mitochondrial stress; protein quality control; proteotoxicity

DOI:  https://doi.org/10.1016/j.celrep.2024.114473
iScience. 2024 Jul 19. 27(7): 110185

Supernumerary proteins of the human mitochondrial ribosomal small subunit are integral for assembly and translation.

Taru Hilander, Ryan Awadhpersad, Geoffray Monteuuis, Krystyna L Broda, Max Pohjanpelto, Elizabeth Pyman, Sachin Kumar Singh, Tuula A Nyman, Isabelle Crevel, Robert W Taylor, Ann Saada, Diego Balboa, Brendan J Battersby, Christopher B Jackson, Christopher J Carroll.

  Mitochondrial ribosomes (mitoribosomes) have undergone substantial evolutionary structural remodeling accompanied by loss of ribosomal RNA, while acquiring unique protein subunits located on the periphery. We generated CRISPR-mediated knockouts of all 14 unique (mitochondria-specific/supernumerary) human mitoribosomal proteins (snMRPs) in the small subunit to study the effect on mitoribosome assembly and protein synthesis, each leading to a unique mitoribosome assembly defect with variable impact on mitochondrial protein synthesis. Surprisingly, the stability of mS37 was reduced in all our snMRP knockouts of the small and large ribosomal subunits and patient-derived lines with mitoribosome assembly defects. A redox-regulated CX9C motif in mS37 was essential for protein stability, suggesting a potential mechanism to regulate mitochondrial protein synthesis. Together, our findings support a modular assembly of the human mitochondrial small ribosomal subunit mediated by essential supernumerary subunits and identify a redox regulatory role involving mS37 in mitochondrial protein synthesis in health and disease.

Keywords:  biochemistry; biological sciences; cell biology; molecular biology

DOI:  https://doi.org/10.1016/j.isci.2024.110185
STAR Protoc. 2024 Jul 15. pii: S2666-1667(24)00292-2. [Epub ahead of print]5(3): 103127

Protocol for evaluating mitochondrial respiration in iPSC-derived neurons by the Seahorse XF analyzer.

Chiara Fasano, Andrea Cavaliere, Valeria Tiranti, Camille Peron.

  Here, we present a protocol describing the quantification of oxygen consumption rate (OCR) and maximal respiration rate (MRR) in living induced pluripotent stem cell (iPSC)-derived neurons using the Seahorse analyzer. We guide you through the whole process: culture amplification and seeding of neural progenitor cells (NPCs), their differentiation into neurons, and normalization of the results to cell number in the analytical phase. The assessment of cellular mitochondrial function, by analyzing mitochondrial respiration, could be useful in various diseases as well as in drug screening. For complete details on the use and execution of this protocol, please refer to Aleo et al.1.

Keywords:  Cell Biology; Metabolism; Stem Cells

DOI:  https://doi.org/10.1016/j.xpro.2024.103127
Physiol Res. 2024 Jul 17.

Variability of Clinical Phenotypes Caused by Isolated Defects of Mitochondrial ATP Synthase (Review).

K Tauchmannová, A Pecinová, J Houštěk, T Mrázek.

Disorders of ATP synthase, the key enzyme in mitochondrial energy supply, belong to the most severe metabolic diseases, manifesting as early-onset mitochondrial encephalo-cardiomyopathies. Since ATP synthase subunits are encoded by both mitochondrial and nuclear DNA, pathogenic variants can be found in either genome. In addition, the biogenesis of ATP synthase requires several assembly factors, some of which are also hotspots for pathogenic variants. While variants of MT-ATP6 and TMEM70 represent the most common cases of mitochondrial and nuclear DNA mutations respectively, the advent of next-generation sequencing has revealed new pathogenic variants in a number of structural genes and TMEM70, sometimes with truly peculiar genetics. Here we present a systematic review of the reported cases and discuss biochemical mechanisms, through which they are affecting ATP synthase. We explore how the knowledge of pathophysiology can improve our understanding of enzyme biogenesis and function.
bioRxiv. 2024 Jul 02. pii: 2024.06.28.601178. [Epub ahead of print]

Anatomical and functional analysis of the corticospinal tract in an FRDA mouse model.

Misa Nishiyama, John Kalambogias, Fumiyasu Imai, Emily Yang, Sonia Lang, Joriene C de Nooij, Yutaka Yoshida.

Friedreich's ataxia (FRDA) is one of the most common hereditary ataxias. It is caused by a GAA repeat in the first intron of the FXN gene, which encodes an essential mitochondrial protein. Patients suffer from progressive motor dysfunction due to the degeneration of mechanoreceptive and proprioceptive neurons in dorsal root ganglia (DRG) and cerebellar dentate nucleus neurons, especially at early disease stages. Postmortem analyses of FRDA patients also indicate pathological changes in motor cortex including in the projection neurons that give rise to the cortical spinal tract (CST). Yet, it remains poorly understood how early in the disease cortical spinal neurons (CSNs) show these alterations, or whether CSN/CST pathology resembles the abnormalities observed in other tissues affected by FXN loss. To address these questions, we examined CSN driven motor behaviors and pathology in the YG8JR FRDA mouse model. We find that FRDA mice show impaired motor skills, exhibit significant reductions in CSN functional output, and, among other pathological changes, show abnormal mitochondrial distributions in CSN neurons and CST axonal tracts. Moreover, some of these alterations were observed as early as two months of age, suggesting that CSN/CST pathology may be an earlier event in FRDA disease than previously appreciated. These studies warrant a detailed mechanistic understanding of how FXN loss impacts CSN health and functionality.

DOI: https://doi.org/10.1101/2024.06.28.601178
Stem Cell Rev Rep. 2024 Jul 17.

Chimeric Cell Therapy Transfers Healthy Donor Mitochondria in Duchenne Muscular Dystrophy.

Maria Siemionow, Katarzyna Bocian, Katarzyna T Bozyk, Anna Ziemiecka, Krzysztof Siemionow.

  Duchenne muscular dystrophy (DMD) is a severe X-linked disorder characterized by dystrophin gene mutations and mitochondrial dysfunction, leading to progressive muscle weakness and premature death of DMD patients. We developed human Dystrophin Expressing Chimeric (DEC) cells, created by the fusion of myoblasts from normal donors and DMD patients, as a foundation for DT-DEC01 therapy for DMD. Our preclinical studies on mdx mouse models of DMD revealed enhanced dystrophin expression and functional improvements in cardiac, respiratory, and skeletal muscles after systemic intraosseous DEC administration. The current study explored the feasibility of mitochondrial transfer and fusion within the created DEC cells, which is crucial for developing new therapeutic strategies for DMD. Following mitochondrial staining with MitoTracker Deep Red and MitoTracker Green dyes, mitochondrial fusion and transfer was assessed by Flow cytometry (FACS) and confocal microscopy. The PEG-mediated fusion of myoblasts from normal healthy donors (MBN/MBN) and normal and DMD-affected donors (MBN/MBDMD), confirmed the feasibility of myoblast and mitochondrial fusion and transfer. The colocalization of the mitochondrial dyes MitoTracker Deep Red and MitoTracker Green confirmed the mitochondrial chimeric state and the creation of chimeric mitochondria, as well as the transfer of healthy donor mitochondria within the created DEC cells. These findings are unique and significant, introducing the potential of DT-DEC01 therapy to restore mitochondrial function in DMD patients and in other diseases where mitochondrial dysfunction plays a critical role.

Keywords:  Chimeric mitochondria; DMD therapy; Dystrophin expressing chimeric (DEC) cells; Mitochondria in DMD; Mitochondrial fusion; Mitochondrial transfer

DOI:  https://doi.org/10.1007/s12015-024-10756-w
Pharmacol Res. 2024 Jul 14. pii: S1043-6618(24)00252-4. [Epub ahead of print]206 107307

Extracellular vesicles meet mitochondria: Potential roles in regenerative medicine.

Shujie Wu, Tao Yang, Meirui Ma, Le Fan, Lin Ren, Gen Liu, Yiqiao Wang, Bin Cheng, Juan Xia, Zhichao Hao.

  Extracellular vesicles (EVs), secreted by most cells, act as natural cell-derived carriers for delivering proteins, nucleic acids, and organelles between cells. Mitochondria are highly dynamic organelles responsible for energy production and cellular physiological processes. Recent evidence has highlighted the pivotal role of EVs in intercellular mitochondrial content transfer, including mitochondrial DNA (mtDNA), proteins, and intact mitochondria. Intriguingly, mitochondria are crucial mediators of EVs release, suggesting an interplay between EVs and mitochondria and their potential implications in physiology and pathology. However, in this expanding field, much remains unknown regarding the function and mechanism of crosstalk between EVs and mitochondria and the transport of mitochondrial EVs. Herein, we shed light on the physiological and pathological functions of EVs and mitochondria, potential mechanisms underlying their interactions, delivery of mitochondria-rich EVs, and their clinical applications in regenerative medicine.

Keywords:  Extracellular vesicles; Mitochondria; Mitochondrial transfer; Regenerative medicine

DOI:  https://doi.org/10.1016/j.phrs.2024.107307
Nat Commun. 2024 Jul 15. 15(1): 5927

Adenine base editing-mediated exon skipping restores dystrophin in humanized Duchenne mouse model.

Jiajia Lin, Ming Jin, Dong Yang, Zhifang Li, Yu Zhang, Qingquan Xiao, Yin Wang, Yuyang Yu, Xiumei Zhang, Zhurui Shao, Linyu Shi, Shu Zhang, Wan-Jin Chen, Ning Wang, Shiwen Wu, Hui Yang, Chunlong Xu, Guoling Li.

Duchenne muscular dystrophy (DMD) affecting 1 in 3500-5000 live male newborns is the frequently fatal genetic disease resulted from various mutations in DMD gene encoding dystrophin protein. About 70% of DMD-causing mutations are exon deletion leading to frameshift of open reading frame and dystrophin deficiency. To facilitate translating human DMD-targeting CRISPR therapeutics into patients, we herein establish a genetically humanized mouse model of DMD by replacing exon 50 and 51 of mouse Dmd gene with human exon 50 sequence. This humanized mouse model recapitulats patient's DMD phenotypes of dystrophin deficiency and muscle dysfunction. Furthermore, we target splicing sites in human exon 50 with adenine base editor to induce exon skipping and robustly restored dystrophin expression in heart, tibialis anterior and diaphragm muscles. Importantly, systemic delivery of base editor via adeno-associated virus in the humanized male mouse model improves the muscle function of DMD mice to the similar level of wildtype ones, indicating the therapeutic efficacy of base editing strategy in treating most of DMD types with exon deletion or point mutations via exon-skipping induction.

DOI: https://doi.org/10.1038/s41467-024-50340-x
Brain. 2024 Jul 13. pii: awae229. [Epub ahead of print]

Synaptic mitochondria glycation contributes to mitochondrial stress and cognitive dysfunction.

Sourav Samanta, Firoz Akhter, Renhao Xue, Alexandre A Sosunov, Long Wu, Doris Chen, Ottavio Arancio, Shi Fang Yan, Shirley ShiDu Yan.

  Mitochondrial and synaptic dysfunction are pathological features of brain aging and cognitive decline. Synaptic mitochondria are vital for meeting the high energy demands of synaptic transmission. However, little is known about the link between age-related metabolic changes and the integrity of synaptic mitochondria. To this end, we investigate the mechanisms of advanced glycation endproducts (AGEs)-mediated mitochondrial and synaptic stress and evaluate the strategies to eliminate these toxic metabolites. Using aged brain and novel transgenic mice overexpressing neuronal glyoxalase 1 (GLO1), we comprehensively analyzed alterations in accumulation/buildup of AGEs and related metabolites in synaptic mitochondria and the association of AGE levels with mitochondrial function. We demonstrate for the first time that synaptic mitochondria are an early and major target of AGEs and the related toxic metabolite methylglyoxal (MG), a precursor of AGEs. MG/AGEs-insulted synaptic mitochondria exhibit deterioration of mitochondrial and synaptic function. Such accumulation of MG/AGEs positively correlated with mitochondrial perturbation and oxidative stress in aging brain. Importantly, clearance of AGEs-related metabolites by enhancing neuronal GLO1, a key enzyme for detoxification/of AGEs, reduces synaptic mitochondrial AGEs accumulation and improves mitochondrial and cognitive function in aging and AGE-challenged mice. Furthermore, we evaluated the direct effect of AGEs on synaptic function in hippocampal neurons in live brain slices as an ex-vivo model and in vitro cultured hippocampal neurons by recording long-term potentiation (LTP) and measuring spontaneously occurring miniature excitatory postsynaptic currents (mEPSCs). Neuronal GLO1 rescues deficits in AGEs-induced synaptic plasticity and transmission by fully recovery of decline in LTP or frequency of mEPSC. These studies explore crosstalk between synaptic mitochondrial dysfunction and age-related metabolic changes relevant to brain aging and cognitive decline. Synaptic mitochondria are particularly susceptible to AGEs-induced damage, highlighting the central importance of synaptic mitochondrial dysfunction in synaptic degeneration in age-related cognitive decline. Thus, augmenting GLO1 function to scavenge toxic metabolites represents a therapeutic approach to reduce age-related AGEs accumulation and to improve mitochondrial function and learning and memory.

Keywords:  AGEs metabolism; glyoxalase I; mitochondrial and oxidative stress; synaptic mitochondria toxicity; synaptic transmission/injury

DOI:  https://doi.org/10.1093/brain/awae229
Proc Natl Acad Sci U S A. 2024 Jul 23. 121(30): e2313609121

Mfn2-dependent fusion pathway of PE-enriched micron-sized vesicles.

Daniel A Peñalva, Ajay K Monnappa, Paolo Natale, Iván López-Montero.

  Mitofusins (Mfn1 and Mfn2) are the mitochondrial outer-membrane fusion proteins in mammals and belong to the dynamin superfamily of multidomain GTPases. Recent structural studies of truncated variants lacking alpha helical transmembrane domains suggested that Mfns dimerize to promote the approximation and the fusion of the mitochondrial outer membranes upon the hydrolysis of guanine 5'-triphosphate disodium salt (GTP). However, next to the presence of GTP, the fusion activity seems to require multiple regulatory factors that control the dynamics and kinetics of mitochondrial fusion through the formation of Mfn1-Mfn2 heterodimers. Here, we purified and reconstituted the full-length murine Mfn2 protein into giant unilamellar vesicles (GUVs) with different lipid compositions. The incubation with GTP resulted in the fusion of Mfn2-GUVs. High-speed video-microscopy showed that the Mfn2-dependent membrane fusion pathway progressed through a zipper mechanism where the formation and growth of an adhesion patch eventually led to the formation of a membrane opening at the rim of the septum. The presence of physiological concentration (up to 30 mol%) of dioleoyl-phosphatidylethanolamine (DOPE) was shown to be a requisite to observe GTP-induced Mfn2-dependent fusion. Our observations show that Mfn2 alone can promote the fusion of micron-sized DOPE-enriched vesicles without the requirement of regulatory cofactors, such as membrane curvature, or the assistance of other proteins.

Keywords:  giant unilamellar vesicles; membrane fusion; mitochondrial dynamics; mitofusin 2

DOI:  https://doi.org/10.1073/pnas.2313609121
Cell Death Dis. 2024 Jul 16. 15(7): 505

Mitophagy-related regulated cell death: molecular mechanisms and disease implications.

Molin Yang, Xiang Wei, Xin Yi, Ding-Sheng Jiang.

During oxidative phosphorylation, mitochondria continuously produce reactive oxygen species (ROS), and untimely ROS clearance can subject mitochondria to oxidative stress, ultimately resulting in mitochondrial damage. Mitophagy is essential for maintaining cellular mitochondrial quality control and homeostasis, with activation involving both ubiquitin-dependent and ubiquitin-independent pathways. Over the past decade, numerous studies have indicated that different forms of regulated cell death (RCD) are connected with mitophagy. These diverse forms of RCD have been shown to be regulated by mitophagy and are implicated in the pathogenesis of a variety of diseases, such as tumors, degenerative diseases, and ischemia‒reperfusion injury (IRI). Importantly, targeting mitophagy to regulate RCD has shown excellent therapeutic potential in preclinical trials, and is expected to be an effective strategy for the treatment of related diseases. Here, we present a summary of the role of mitophagy in different forms of RCD, with a focus on potential molecular mechanisms by which mitophagy regulates RCD. We also discuss the implications of mitophagy-related RCD in the context of various diseases.

DOI: https://doi.org/10.1038/s41419-024-06804-5
EMBO Rep. 2024 Jul 18.

The actin binding protein profilin 1 localizes inside mitochondria and is critical for their function.

Tracy-Ann Read, Bruno A Cisterna, Kristen Skruber, Samah Ahmadieh, Tatiana M Liu, Josefine A Vitriol, Yang Shi, Joseph B Black, Mitchell T Butler, Halli L Lindamood, Austin Eyt Lefebvre, Alena Cherezova, Daria V Ilatovskaya, James E Bear, Neal L Weintraub, Eric A Vitriol.

  The monomer-binding protein profilin 1 (PFN1) plays a crucial role in actin polymerization. However, mutations in PFN1 are also linked to hereditary amyotrophic lateral sclerosis, resulting in a broad range of cellular pathologies which cannot be explained by its primary function as a cytosolic actin assembly factor. This implies that there are important, undiscovered roles for PFN1 in cellular physiology. Here we screened knockout cells for novel phenotypes associated with PFN1 loss of function and discovered that mitophagy was significantly upregulated. Indeed, despite successful autophagosome formation, fusion with the lysosome, and activation of additional mitochondrial quality control pathways, PFN1 knockout cells accumulate depolarized, dysmorphic mitochondria with altered metabolic properties. Surprisingly, we also discovered that PFN1 is present inside mitochondria and provide evidence that mitochondrial defects associated with PFN1 loss are not caused by reduced actin polymerization in the cytosol. These findings suggest a previously unrecognized role for PFN1 in maintaining mitochondrial integrity and highlight new pathogenic mechanisms that can result from PFN1 dysregulation.

Keywords:  Actin; Mitochondria; Mitochondrial-derived Vesicles; Mitophagy; Profilin

DOI:  https://doi.org/10.1038/s44319-024-00209-3
J Inflamm Res. 2024 ;17 4549-4574

Novel Insights into Parkin-Mediated Mitochondrial Dysfunction and "Mito-Inflammation" in α-Synuclein Toxicity. The Role of the cGAS-STING Signalling Pathway.

Magdalena Gąssowska-Dobrowolska, Gabriela Olech-Kochańczyk, Carsten Culmsee, Agata Adamczyk.

  The prevalence of age-related neurodegenerative diseases, such as Parkinson's disease (PD) and related disorders continues to grow worldwide. Increasing evidence links intracellular inclusions of misfolded alpha-synuclein (α-syn) aggregates, so-called Lewy bodies (LB) and Lewy neuritis, to the progressive pathology of PD and other synucleinopathies. Our previous findings established that α-syn oligomers induce S-nitrosylation and deregulation of the E3-ubiquitin ligase Parkin, leading to mitochondrial disturbances in neuronal cells. The accumulation of damaged mitochondria as a consequence, together with the release of mitochondrial-derived damage-associated molecular patterns (mtDAMPs) could activate the innate immune response and induce neuroinflammation ("mito-inflammation"), eventually accelerating neurodegeneration. However, the molecular pathways that transmit pro-inflammatory signals from damaged mitochondria are not well understood. One of the proposed pathways could be the cyclic GMP-AMP synthase (cGAS) - stimulator of interferon genes (STING) (cGAS-STING) pathway, which plays a pivotal role in modulating the innate immune response. It has recently been suggested that cGAS-STING deregulation may contribute to the development of various pathological conditions. Especially, its excessive engagement may lead to neuroinflammation and appear to be essential for the development of neurodegenerative brain diseases, including PD. However, the precise molecular mechanisms underlying cGAS-STING pathway activation in PD and other synucleinopathies are not fully understood. This review focuses on linking mitochondrial dysfunction to neuroinflammation in these disorders, particularly emphasizing the role of the cGAS-STING signaling. We propose the cGAS-STING pathway as a critical driver of inflammation in α-syn-dependent neurodegeneration and hypothesize that cGAS-STING-driven "mito-inflammation" may be one of the key mechanisms promoting the neurodegeneration in PD. Understanding the molecular mechanisms of α-syn-induced cGAS-STING-associated "mito-inflammation" in PD and related synucleinopathies may contribute to the identification of new targets for the treatment of these disorders.

Keywords:  Parkin; cGAS–STING pathway; mito-inflammation; mtDAMPs; sterile inflammation; α-synuclein

DOI:  https://doi.org/10.2147/JIR.S468609
Nat Commun. 2024 Jul 15. 15(1): 5937

Single-cell multiomics reveals ENL mutation perturbs kidney developmental trajectory by rewiring gene regulatory landscape.

Lele Song, Qinglan Li, Lingbo Xia, Arushi Eesha Sahay, Qi Qiu, Yuanyuan Li, Haitao Li, Kotaro Sasaki, Katalin Susztak, Hao Wu, Liling Wan.

How disruptions to normal cell differentiation link to tumorigenesis remains incompletely understood. Wilms tumor, an embryonal tumor associated with disrupted organogenesis, often harbors mutations in epigenetic regulators, but their role in kidney development remains unexplored. Here, we show at single-cell resolution that a Wilms tumor-associated mutation in the histone acetylation reader ENL disrupts kidney differentiation in mice by rewiring the gene regulatory landscape. Mutant ENL promotes nephron progenitor commitment while restricting their differentiation by dysregulating transcription factors such as Hox clusters. It also induces abnormal progenitors that lose kidney-associated chromatin identity. Furthermore, mutant ENL alters the transcriptome and chromatin accessibility of stromal progenitors, resulting in hyperactivation of Wnt signaling. The impacts of mutant ENL on both nephron and stroma lineages lead to profound kidney developmental defects and postnatal mortality in mice. Notably, a small molecule inhibiting mutant ENL's histone acetylation binding activity largely reverses these defects. This study provides insights into how mutations in epigenetic regulators disrupt kidney development and suggests a potential therapeutic approach.

DOI: https://doi.org/10.1038/s41467-024-50171-w
Cell Rep. 2024 Jul 18. pii: S2211-1247(24)00822-2. [Epub ahead of print]43(8): 114493

Mitochondrial perturbations in low-protein-diet-fed mice are associated with altered neutrophil development and effector functions.

Mehakpreet K Thind, Emiliano Miraglia, Catriona Ling, Meraj A Khan, Aida Glembocki, Celine Bourdon, YueYing ChenMi, Nades Palaniyar, Michael Glogauer, Robert H J Bandsma, Amber Farooqui.

  Severe malnutrition is associated with infections, namely lower respiratory tract infections (LRTIs), diarrhea, and sepsis, and underlies the high risk of morbidity and mortality in children under 5 years of age. Dysregulations in neutrophil responses in the acute phase of infection are speculated to underlie these severe adverse outcomes; however, very little is known about their biology in this context. Here, in a lipopolysaccharide-challenged low-protein diet (LPD) mouse model, as a model of malnutrition, we show that protein deficiency disrupts neutrophil mitochondrial dynamics and ATP generation to obstruct the neutrophil differentiation cascade. This promotes the accumulation of atypical immature neutrophils that are incapable of optimal antimicrobial response and, in turn, exacerbate systemic pathogen spread and the permeability of the alveolocapillary membrane with the resultant lung damage. Thus, this perturbed response may contribute to higher mortality risk in malnutrition. We also offer a nutritional therapeutic strategy, nicotinamide, to boost neutrophil-mediated immunity in LPD-fed mice.

Keywords:  CP: Immunology; CP: Microbiology; cellular metabolism; development and functions; immunometabolism; low-protein diet; malnutrition; neutrophils

DOI:  https://doi.org/10.1016/j.celrep.2024.114493
Heliyon. 2024 Jun 30. 10(12): e33132

HTR1B regulates mitochondrial homeostasis and mitophagy by activating the ERK/ MAPK signalling pathway during human embryonic arrest.

Si-Min Ding, Ling-Ge Shi, Zhen-Ping Cao, Na-Na Zhu, Yun-Yun Liu, Meng-Yao Wang, Shuang-Shuang Cui, Hui-Ru Cheng, Dan Liang, Yun-Xia Cao, Ya-Jing Liu.

  Background: Previous studies have shown that serotonin and its receptors are widely distributed in mammalian reproductive tisssues and play an important role in embryonic development. However, the specific effects of the serotonergic system on embryonic arrest (EA) and the underlying mechanism require further investigation.Methods: Chorionic villi were collected from patients with EA and healthy pregnant women. Western blotting (WB) and immunohistochemistry (IHC) were used to detect serotonin receptor 1B (HTR1B) levels and evaluate mitochondrial function. Additionally, HTR-8/SVneo cells were transfected with an HTR1B overexpression plasmid. Quantitative real-time polymerase chain reaction(qRT-PCR), Cell Counting Kit-8 (CCK-8), and wound healing assays were utilized to evaluate mitophagy level, cell proliferation and cell migration, respectively.
Results: We discovered elevated HTR1B levels in the chorionic villi of the patients with EA compared to controls. Concurrently, we observed enhanced levels of nucleus-encoded proteins including mitofilin, succinate dehydrogenase complex subunit A (SDHA), and cytochrome c oxidase subunit 4 (COXIV), along with the mitochondrial fusion protein optic atrophy 1(OPA1), fission proteins mitochondrial fission protein 1(FIS1) and mitochondrial fission factor (MFF) in the EA group. Additionally, there was an excessive mitophagy levels in EA group. Furthermore, a notable activation of mitogen-activated protein kinase (MAPK) signaling pathway proteins including extracellular regulating kinase (ERK), c-Jun N-terminal kinase (JNK), and P38 was observed in the EA group. By overexpressing HTR1B in HTR-8/SVneo cells, we observed a significant reduction in cell proliferation and migration. HTR1B overexpression also caused an increase in levels of SDHA and FIS1, as well as an upregulation of mitophagy. Notably, the ERK inhibitor U0126 effectively mitigated these effects.
Conclusion: These findings show that HTR1B influences mitochondrial homeostasis, promoting excessive mitophagy and impairing cell proliferation and migration by activating the MAPK signalling pathway during post-implantation EA. Therefore, HTR1B may serve as a potential therapeutic target for patients with EA.

Keywords:  Embryonic arrest; Excessive mitophagy; HTR1B; MAPK; Mitochondrial fission protein; Mitochondrial fusion protein

DOI:  https://doi.org/10.1016/j.heliyon.2024.e33132
Nat Commun. 2024 Jul 13. 15(1): 5898

Early human fetal lung atlas reveals the temporal dynamics of epithelial cell plasticity.

Henry Quach, Spencer Farrell, Ming Jia Michael Wu, Kayshani Kanagarajah, Joseph Wai-Hin Leung, Xiaoqiao Xu, Prajkta Kallurkar, Andrei L Turinsky, Christine E Bear, Felix Ratjen, Brian Kalish, Sidhartha Goyal, Theo J Moraes, Amy P Wong.

Studying human fetal lungs can inform how developmental defects and disease states alter the function of the lungs. Here, we sequenced >150,000 single cells from 19 healthy human pseudoglandular fetal lung tissues ranging between gestational weeks 10-19. We capture dynamic developmental trajectories from progenitor cells that express abundant levels of the cystic fibrosis conductance transmembrane regulator (CFTR). These cells give rise to multiple specialized epithelial cell types. Combined with spatial transcriptomics, we show temporal regulation of key signalling pathways that may drive the temporal and spatial emergence of specialized epithelial cells including ciliated and pulmonary neuroendocrine cells. Finally, we show that human pluripotent stem cell-derived fetal lung models contain CFTR-expressing progenitor cells that capture similar lineage developmental trajectories as identified in the native tissue. Overall, this study provides a comprehensive single-cell atlas of the developing human lung, outlining the temporal and spatial complexities of cell lineage development and benchmarks fetal lung cultures from human pluripotent stem cell differentiations to similar developmental window.

DOI: https://doi.org/10.1038/s41467-024-50281-5
Neurobiol Dis. 2024 Jul 11. pii: S0969-9961(24)00204-3. [Epub ahead of print]199 106604

Mitochondrial regulation of adult hippocampal neurogenesis: Insights into neurological function and neurodevelopmental disorders.

Sara Bonzano, Eleonora Dallorto, Serena Bovetti, Michèle Studer, Silvia De Marchis.

  Mitochondria are essential regulators of cellular energy metabolism and play a crucial role in the maintenance and function of neuronal cells. Studies in the last decade have highlighted the importance of mitochondrial dynamics and bioenergetics in adult neurogenesis, a process that significantly influences cognitive function and brain plasticity. In this review, we examine the mechanisms by which mitochondria regulate adult neurogenesis, focusing on the impact of mitochondrial function on the behavior of neural stem/progenitor cells and the maturation and plasticity of newborn neurons in the adult mouse hippocampus. In addition, we explore the link between mitochondrial dysfunction, adult hippocampal neurogenesis and genes associated with cognitive deficits in neurodevelopmental disorders. In particular, we provide insights into how alterations in the transcriptional regulator NR2F1 affect mitochondrial dynamics and may contribute to the pathophysiology of the emerging neurodevelopmental disorder Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS). Understanding how genes involved in embryonic and adult neurogenesis affect mitochondrial function in neurological diseases might open new directions for therapeutic interventions aimed at boosting mitochondrial function during postnatal life.

Keywords:  Adult neural stem cells; BBSOAS; Dentate gyrus; Mitochondria; Nr2f1

DOI:  https://doi.org/10.1016/j.nbd.2024.106604
Cardiovasc Toxicol. 2024 Jul 16.

Mitotherapy with Fresh Isolated Cardiac Mitochondria Via Injection Into Blood Reduces Aluminum Phosphide-Induced Mortality and Protects Cardiac Tissue Against Oxidative Stress and Mitochondrial Damages.

Mohammad Shabani, Saleh Khezri, Ahmad Salimi.

  The hallmark of aluminum phosphide (AlP) poisoning is heart failure in victims which is associated with reactive oxygen species (ROS), mitochondrial dysfunction, oxidative stress, alteration in antioxidant defense system and depletion of ATP in cardiomyocytes. In the present study, we hypothesized that the injection of isolated mitochondria into blood or mitochondrial transplantation can likely create a primary target for phosphine released from AlP and inhibit AlP-induced mortality and cardiotoxicity in rat. Male, Wistar, healthy and adult rats were randomly divided into 5 groups as control, AlP (12.5 mg/kg, orally), AlP + mitochondria (125 µg/kg), AlP + mitochondria (250 µg/kg) and mitochondria (250 µg/kg) alone. Functional and intact mitochondria isolated from rat heart and transplantation was carried out via tail vein, 30 min after exposure to AlP. Survival rate, histopathological alterations, cardiac biochemical markers, oxidative stress and mitochondrial toxicity parameters were monitored and analyzed during 30 days. We found that injection of healthy mitochondria into blood at concentrations of 125 and 250 125 µg/ml significantly increased the survival of rats up to 40% and 56.25% respectively, during 30 days. Moreover, we observed that mitochondria injection into blood decreased histopathological damages, cardiac biochemical markers, oxidative stress and mitochondrial toxicity parameters. To our knowledge, the current study is the first report in the literature that demonstrated good therapeutic effects of mitochondrial transplantation in AlP-induced mortality and cardiotoxicity. The findings of the present study suggests that injection of exogenous mitochondria into blood could be an effective therapeutic strategy in treating AlP poisoning.

Keywords:  Cardiovascular Disorders; Mitochondria Replenishment; Mitochondrial Toxicity; Pesticides; Poisoning

DOI:  https://doi.org/10.1007/s12012-024-09896-9
Transl Psychiatry. 2024 Jul 16. 14(1): 289

Prenatal immune activation in mice induces long-term alterations in brain mitochondrial function.

Edith M Schneider Gasser, Ron Schaer, Flavia S Mueller, Alexandra C Bernhardt, Han-Yu Lin, Christian Arias-Reyes, Ulrike Weber-Stadlbauer.

Prenatal exposure to infections is a risk factor for neurodevelopmental disorders in offspring, and alterations in mitochondrial function are discussed as a potential underlying factor. Here, using a mouse model of viral-like maternal immune activation (MIA) based on poly(I:C) (POL) treatment at gestational day (GD) 12, we show that adult offspring exhibit behavioral deficits, such as reduced levels of social interaction. In addition, we found increased nicotinamidadenindinucleotid (NADH)- and succinate-linked mitochondrial respiration and maximal electron transfer capacity in the prefrontal cortex (PFC) and in the amygdala (AMY) of males and females. The increase in respiratory capacity resulted from an increase in mitochondrial mass in neurons (as measured by complex IV activity and transcript expression), presumably to compensate for a reduction in mitochondrion-specific respiration. Moreover, in the PFC of control (CON) male offspring a higher excess capacity compared to females was observed, which was significantly reduced in the POL-exposed male offspring, and, along with a higher leak respiration, resulted in a lower mitochondrial coupling efficiency. Transcript expression of the uncoupling proteins (UCP4 and UCP5) showed a reduction in the PFC of POL male mice, suggesting mitochondrial dysfunction. In addition, in the PFC of CON females, a higher expression of the antioxidant enzyme superoxide dismutase (SOD1) was observed, suggesting a higher antioxidant capacity as compared to males. Finally, transcripts analysis of genes involved in mitochondrial biogenesis and dynamics showed reduced expression of fission/fusion transcripts in PFC of POL offspring of both sexes. In conclusion, we show that MIA causes alterations in neuronal mitochondrial function and mass in the PFC and AMY of adult offspring with some effects differing between males and females.

DOI: https://doi.org/10.1038/s41398-024-03010-x
Methods Mol Biol. 2024 ;2805 3-18

Isolation, Culture, and Phenotypic Analysis of Murine Lung Organoids.

Kelly Evans, Catherine Dabrowska, Minn E Ng, Christine F Brainson, Joo-Hyeon Lee.

  Three-dimensional (3D) organoid cultures retain self-renewing stem cells that differentiate into multiple cell types that display spatial organization and functional key features, providing a highly physiological relevant system. Here we describe a strategy for the generation of 3D murine lung organoids derived from freshly isolated primary tracheal and distal lung epithelial stem cells. Isolated tracheas are subjected to enzymatic digestion to release the epithelial layer that is then dissociated into a single cell suspension for organoid culture. Lung epithelial cells are obtained from dissected lobes, which are applied to mechanical and enzymatic dissociation. After flow sorting, organoids are established from tracheal basal, secretory club, and alveolar type 2 cells in the defined conditioned medium that is required to sustain organoid growth and generate the differentiated cells. Multi-cell-type organoid co-culture replicates niches for distal epithelial stem cells to differentiate into bronchiolar and alveolar cell types. Established organoids can be fixed for wholemount staining and paraffin embedding, or passaged for further culture. Taken together, this protocol provides an efficient and validated approach to generate murine lung organoids, as well as a platform for further analysis.

Keywords:  Lung organoids; Lung stem cells; Organoid co-culture; Wholemount staining

DOI:  https://doi.org/10.1007/978-1-0716-3854-5_1
Front Neurol. 2024 ;15 1411987

Interdisciplinary fetal-neonatal neurology training improves brain health across the lifespan.

Mark S Scher.

  Integrated fetal, neonatal, and pediatric training constitute an interdisciplinary fetal-neonatal neurology (FNN) program. A dynamic neural exposome concept strengthens curriculum content. Trainees participate in mentoring committee selection for guidance during a proposed two-year program. Prenatal to postnatal clinical learning re-enforces early toxic stressor interplay that influences gene-environment interactions. Maternal-placental-fetal triad, neonatal, or childhood diseases require diagnostic and therapeutic decisions during the first 1,000 days when 80 % of neural connections contribute to life-course phenotypic expression. Pediatric follow-up through 3 years adjusts to gestational ages of preterm survivors. Cumulative reproductive, pregnancy, pediatric and adult exposome effects require educational experiences that emphasize a principle-to-practice approach to a brain capital strategy across the lifespan. More rigorous training during fetal, neonatal, and pediatric rotations will be offered to full time trainees. Adult neurology residents, medical students, and trainees from diverse disciplines will learn essential topics during time-limited rotations. Curriculum content will require periodic re-assessments using educational science standards that maintain competence while promoting creative and collaborative problem-solving. Continued career-long learning by FNN graduates will strengthen shared healthcare decisions by all stakeholders. Recognition of adaptive or maladaptive neuroplasticity mechanisms requires analytic skills that identify phenotypes associated with disease pathways. Developmental origins and life-course concepts emphasize brain health across the developmental-aging continuum, applicable to interdisciplinary research collaborations. Social determinants of health recognize diversity, equity, and inclusion priorities with each neurological intervention, particularly for those challenged with disparities. Diagnostic and therapeutic strategies must address resource challenges particularly throughout the Global South to effectively lower the worldwide burden of neurologic disease. Sustainable development goals proposed by the World Health Organization offer universally applicable guidelines in response to ongoing global and regional polycrises. Gender, race, ethnicity, and socio-economic equality promote effective preventive, rescue and reparative neuroprotective interventions. Global synergistic efforts can be enhanced by establishing leadership within academic teaching hubs in FNN training to assist with structure and guidance for smaller healthcare facilities in each community that will improve practice, education and research objectives. Reduced mortality with an improved quality of life must prioritize maternal-pediatric health and well-being to sustain brain health across each lifespan with transgenerational benefits.

Keywords:  brain health; developmental origins; diversity-equity-inclusion; global educational synergy; healthcare disparities; interdisciplinary fetal-neonatal neurology training; life course; neural exposome

DOI:  https://doi.org/10.3389/fneur.2024.1411987
PLoS One. 2024 ;19(7): e0305742

In utero adeno-associated virus (AAV)-mediated gene delivery targeting sensory and supporting cells in the embryonic mouse inner ear.

Carla Maria Barbosa Spinola, Jacques Boutet de Monvel, Saaid Safieddine, Ghizlène Lahlou, Raphaël Etournay.

In vivo gene delivery to tissues using adeno-associated vector (AAVs) has revolutionized the field of gene therapy. Yet, while sensorineural hearing loss is one of the most common sensory disorders worldwide, gene therapy applied to the human inner ear is still in its infancy. Recent advances in the development recombinant AAVs have significantly improved their cell tropism and transduction efficiency across diverse inner ear cell types to a level that renders this tool valuable for conditionally manipulating gene expression in the context of developmental biology studies of the mouse inner ear. Here, we describe a protocol for in utero micro-injection of AAVs into the embryonic inner ear, using the AAV-PHP.eB and AAV-DJ serotypes that respectively target the sensory hair cells and the supporting cells of the auditory sensory epithelium. We also aimed to standardize procedures for imaging acquisition and image analysis to foster research reproducibility and allow accurate comparisons between studies. We find that AAV-PHP.eB and AAV-DJ provide efficient and reliable tools for conditional gene expression targeting cochlear sensory and supporting cells in the mouse inner ear, from late embryonic stages on.

DOI: https://doi.org/10.1371/journal.pone.0305742