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Life Science Alliance Sep 2024In addition to mitochondrial DNA, mitochondrial double-stranded RNA (mtdsRNA) is exported from mitochondria. However, specific channels for RNA transport have not been...
In addition to mitochondrial DNA, mitochondrial double-stranded RNA (mtdsRNA) is exported from mitochondria. However, specific channels for RNA transport have not been demonstrated. Here, we begin to characterize channel candidates for mtdsRNA export from the mitochondrial matrix to the cytosol. Down-regulation of SUV3 resulted in the accumulation of mtdsRNAs in the matrix, whereas down-regulation of PNPase resulted in the export of mtdsRNAs to the cytosol. Targeting experiments show that PNPase functions in both the intermembrane space and matrix. Strand-specific sequencing of the double-stranded RNA confirms the mitochondrial origin. Inhibiting or down-regulating outer membrane proteins VDAC1/2 and BAK/BAX or inner membrane proteins PHB1/2 strongly attenuated the export of mtdsRNAs to the cytosol. The cytosolic mtdsRNAs subsequently localized to large granules containing the stress protein TIA-1 and activated the type 1 interferon stress response pathway. Abundant mtdsRNAs were detected in a subset of non-small-cell lung cancer cell lines that were glycolytic, indicating relevance in cancer biology. Thus, we propose that mtdsRNA is a new damage-associated molecular pattern that is exported from mitochondria in a regulated manner.
Topics: Humans; Cytosol; Mitochondria; RNA, Double-Stranded; Prohibitins; RNA, Mitochondrial; Cell Line, Tumor; Repressor Proteins; RNA Transport; Exoribonucleases; Voltage-Dependent Anion Channel 1; Carcinoma, Non-Small-Cell Lung; Mitochondrial Proteins
PubMed: 38955468
DOI: 10.26508/lsa.202302396 -
PloS One 2024Chromatin exhibits non-random distribution within the nucleus being arranged into discrete domains that are spatially organized throughout the nuclear space. Both the...
Chromatin exhibits non-random distribution within the nucleus being arranged into discrete domains that are spatially organized throughout the nuclear space. Both the spatial distribution and structural rearrangement of chromatin domains in the nucleus depend on epigenetic modifications of DNA and/or histones and structural elements such as the nuclear envelope. These components collectively contribute to the organization and rearrangement of chromatin domains, thereby influencing genome architecture and functional regulation. This study develops an innovative, user-friendly, ImageJ-based plugin, called IsoConcentraChromJ, aimed quantitatively delineating the spatial distribution of chromatin regions in concentric patterns. The IsoConcentraChromJ can be applied to quantitative chromatin analysis in both two- and three-dimensional spaces. After DNA and histone staining with fluorescent probes, high-resolution images of nuclei have been obtained using advanced fluorescence microscopy approaches, including confocal and stimulated emission depletion (STED) microscopy. IsoConcentraChromJ workflow comprises the following sequential steps: nucleus segmentation, thresholding, masking, normalization, and trisection with specified ratios for either 2D or 3D acquisitions. The effectiveness of the IsoConcentraChromJ has been validated and demonstrated using experimental datasets consisting in nuclei images of pre-adipocytes and mature adipocytes, encompassing both 2D and 3D imaging. The outcomes allow to characterize the nuclear architecture by calculating the ratios between specific concentric nuclear areas/volumes of acetylated chromatin with respect to total acetylated chromatin and/or total DNA. The novel IsoConcentrapChromJ plugin could represent a valuable resource for researchers investigating the rearrangement of chromatin architecture driven by epigenetic mechanisms using nuclear images obtained by different fluorescence microscopy methods.
Topics: Chromatin; Cell Nucleus; Animals; Mice; Microscopy, Fluorescence; Humans; Histones; Software; Imaging, Three-Dimensional; Image Processing, Computer-Assisted
PubMed: 38954704
DOI: 10.1371/journal.pone.0305809 -
ELife Jul 2024We studied lysosomal Ca in inflammasome. Lipopolysaccharide (LPS) + palmitic acid (PA) decreased lysosomal Ca ([Ca]) and increased [Ca] through mitochondrial ROS, which...
We studied lysosomal Ca in inflammasome. Lipopolysaccharide (LPS) + palmitic acid (PA) decreased lysosomal Ca ([Ca]) and increased [Ca] through mitochondrial ROS, which was suppressed in -KO macrophages. Inflammasome activation and metabolic inflammation in adipose tissue of high-fat diet (HFD)-fed mice were ameliorated by KO. ER→lysosome Ca refilling occurred after lysosomal Ca release whose blockade attenuated LPS + PA-induced inflammasome. Subsequently, store-operated Caentry (SOCE) was activated whose inhibition suppressed inflammasome. SOCE was coupled with K efflux whose inhibition reduced ER Ca content ([Ca]) and impaired [Ca] recovery. LPS + PA activated KCa3.1 channel, a Ca-activated K channel. Inhibitors of KCa3.1 channel or KO reduced [Ca], attenuated increase of [Ca] or inflammasome activation by LPS + PA, and ameliorated HFD-induced inflammasome or metabolic inflammation. Lysosomal Ca release induced delayed JNK and ASC phosphorylation through CAMKII-ASK1. These results suggest a novel role of lysosomal Ca release sustained by ERlysosome Ca refilling and K efflux through KCa3.1 channel in inflammasome activation and metabolic inflammation.
Topics: Animals; Inflammasomes; Mice; Lysosomes; Calcium; Potassium; Inflammation; Mice, Knockout; Endoplasmic Reticulum; Lipopolysaccharides; TRPM Cation Channels; Intermediate-Conductance Calcium-Activated Potassium Channels; Mice, Inbred C57BL; Macrophages; Male; Diet, High-Fat
PubMed: 38953285
DOI: 10.7554/eLife.87561 -
Frontiers in Endocrinology 2024Ovarian aging is a complex process characterized by a decline in oocyte quantity and quality, directly impacting fertility and overall well-being. Recent researches have... (Review)
Review
Ovarian aging is a complex process characterized by a decline in oocyte quantity and quality, directly impacting fertility and overall well-being. Recent researches have identified mitochondria as pivotal players in the aging of ovaries, influencing various hallmarks and pathways governing this intricate process. In this review, we discuss the multifaceted role of mitochondria in determining ovarian fate, and outline the pivotal mechanisms through which mitochondria contribute to ovarian aging. Specifically, we emphasize the potential of targeting mitochondrial dysfunction through innovative therapeutic approaches, including antioxidants, metabolic improvement, biogenesis promotion, mitophagy enhancement, mitochondrial transfer, and traditional Chinese medicine. These strategies hold promise as effective means to mitigate age-related fertility decline and preserve ovarian health. Drawing insights from advanced researches in the field, this review provides a deeper understanding of the intricate interplay between mitochondrial function and ovarian aging, offering valuable perspectives for the development of novel therapeutic interventions aimed at preserving fertility and enhancing overall reproductive health.
Topics: Humans; Female; Mitochondria; Aging; Ovary; Animals; Antioxidants; Oocytes; Mitophagy
PubMed: 38952389
DOI: 10.3389/fendo.2024.1417007 -
Molecular Cancer Jun 2024Natural killer (NK) cells are important immune cells in the organism and are the third major type of lymphocytes besides T cells and B cells, which play an important... (Review)
Review
Natural killer (NK) cells are important immune cells in the organism and are the third major type of lymphocytes besides T cells and B cells, which play an important function in cancer therapy. In addition to retaining the tumor cell killing function of natural killer cells, natural killer cell-derived exosomes cells also have the characteristics of high safety, wide source, easy to preserve and transport. At the same time, natural killer cell-derived exosomes are easy to modify, and the engineered exosomes can be used in combination with a variety of current cancer therapies, which not only enhances the therapeutic efficacy, but also significantly reduces the side effects. Therefore, this review summarizes the source, isolation and modification strategies of natural killer cell-derived exosomes and the combined application of natural killer cell-derived engineered exosomes with other antitumor therapies, which is expected to accelerate the clinical translation process of natural killer cell-derived engineered exosomes in cancer therapy.
Topics: Humans; Exosomes; Killer Cells, Natural; Neoplasms; Animals; Clinical Relevance
PubMed: 38951879
DOI: 10.1186/s12943-024-02045-4 -
Journal of Nanobiotechnology Jul 2024Reperfusion therapy is critical for saving heart muscle after myocardial infarction, but the process of restoring blood flow can itself exacerbate injury to the...
Targeting delivery of miR-146a via IMTP modified milk exosomes exerted cardioprotective effects by inhibiting NF-κB signaling pathway after myocardial ischemia-reperfusion injury.
Reperfusion therapy is critical for saving heart muscle after myocardial infarction, but the process of restoring blood flow can itself exacerbate injury to the myocardium. This phenomenon is known as myocardial ischemia-reperfusion injury (MIRI), which includes oxidative stress, inflammation, and further cell death. microRNA-146a (miR-146a) is known to play a significant role in regulating the immune response and inflammation, and has been studied for its potential impact on the improvement of heart function after myocardial injury. However, the delivery of miR-146a to the heart in a specific and efficient manner remains a challenge as extracellular RNAs are unstable and rapidly degraded. Milk exosomes (MEs) have been proposed as ideal delivery platform for miRNA-based therapy as they can protect miRNAs from RNase degradation. In this study, the effects of miR-146a containing MEs (MEs-miR-146a) on improvement of cardiac function were examined in a rat model of MIRI. To enhance the targeting delivery of MEs-miR-146a to the site of myocardial injury, the ischemic myocardium-targeted peptide IMTP was modified onto the surfaces, and whether the modified MEs-miR-146a could exert a better therapeutic role was examined by echocardiography, myocardial injury indicators and the levels of inflammatory factors. Furthermore, the expressions of miR-146a mediated NF-κB signaling pathway-related proteins were detected by western blotting and qRT-PCR to further elucidate its mechanisms. MiR-146 mimics were successfully loaded into the MEs by electroporation at a square wave 1000 V voltage and 0.1 ms pulse duration. MEs-miR-146a can be up-taken by cardiomyocytes and protected the cells from oxygen glucose deprivation/reperfusion induced damage in vitro. Oral administration of MEs-miR-146a decreased myocardial tissue apoptosis and the expression of inflammatory factors and improved cardiac function after MIRI. The miR-146a level in myocardium tissues was significantly increased after the administration IMTP modified MEs-miR-146a, which was higher than that of the MEs-miR-146a group. In addition, intravenous injection of IMTP modified MEs-miR-146a enhanced the targeting to heart, improved cardiac function, reduced myocardial tissue apoptosis and suppressed inflammation after MIRI, which was more effective than the MEs-miR-146a treatment. Moreover, IMTP modified MEs-miR-146a reduced the protein levels of IRAK1, TRAF6 and p-p65. Therefore, IMTP modified MEs-miR-146a exerted their anti-inflammatory effect by inhibiting the IRAK1/TRAF6/NF-κB signaling pathway. Taken together, our findings suggested miR-146a containing MEs may be a promising strategy for the treatment of MIRI with better outcome after modification with ischemic myocardium-targeted peptide, which was expected to be applied in clinical practice in future.
Topics: Animals; MicroRNAs; Myocardial Reperfusion Injury; Exosomes; NF-kappa B; Signal Transduction; Rats; Rats, Sprague-Dawley; Male; Milk; Myocardium; Cardiotonic Agents; Myocytes, Cardiac
PubMed: 38951872
DOI: 10.1186/s12951-024-02631-0 -
Journal of Nanobiotechnology Jul 2024Numerous studies have confirmed the involvement of extracellular vesicles (EVs) in various physiological processes, including cellular death and tissue damage. Recently,...
BACKGROUND
Numerous studies have confirmed the involvement of extracellular vesicles (EVs) in various physiological processes, including cellular death and tissue damage. Recently, we reported that EVs derived from ischemia-reperfusion heart exacerbate cardiac injury. However, the role of EVs from healthy heart tissue (heart-derived EVs, or cEVs) on myocardial ischemia-reperfusion (MI/R) injury remains unclear.
RESULTS
Here, we demonstrated that intramyocardial administration of cEVs significantly enhanced cardiac function and reduced cardiac damage in murine MI/R injury models. cEVs treatment effectively inhibited ferroptosis and maintained mitochondrial homeostasis in cardiomyocytes subjected to ischemia-reperfusion injury. Further results revealed that cEVs can transfer ATP5a1 into cardiomyocytes, thereby suppressing mitochondrial ROS production, alleviating mitochondrial damage, and inhibiting cardiomyocyte ferroptosis. Knockdown of ATP5a1 abolished the protective effects of cEVs. Furthermore, we found that the majority of cEVs are derived from cardiomyocytes, and ATP5a1 in cEVs primarily originates from cardiomyocytes of the healthy murine heart. Moreover, we demonstrated that adipose-derived stem cells (ADSC)-derived EVs with ATP5a1 overexpression showed much better efficacy on the therapy of MI/R injury compared to control ADSC-derived EVs.
CONCLUSIONS
These findings emphasized the protective role of cEVs in cardiac injury and highlighted the therapeutic potential of targeting ATP5a1 as an important approach for managing myocardial damage induced by MI/R injury.
Topics: Animals; Extracellular Vesicles; Mice; Myocardial Reperfusion Injury; Myocytes, Cardiac; Male; Mice, Inbred C57BL; Mitochondrial Proton-Translocating ATPases; Mitochondria; Myocardium; Reactive Oxygen Species; Ferroptosis; Disease Models, Animal
PubMed: 38951822
DOI: 10.1186/s12951-024-02618-x -
Communications Biology Jul 2024The peroxisome is a versatile organelle that performs diverse metabolic functions. PEX3, a critical regulator of the peroxisome, participates in various biological...
The peroxisome is a versatile organelle that performs diverse metabolic functions. PEX3, a critical regulator of the peroxisome, participates in various biological processes associated with the peroxisome. Whether PEX3 is involved in peroxisome-related redox homeostasis and myocardial regenerative repair remains elusive. We investigate that cardiomyocyte-specific PEX3 knockout (Pex3-KO) results in an imbalance of redox homeostasis and disrupts the endogenous proliferation/development at different times and spatial locations. Using Pex3-KO mice and myocardium-targeted intervention approaches, the effects of PEX3 on myocardial regenerative repair during both physiological and pathological stages are explored. Mechanistically, lipid metabolomics reveals that PEX3 promotes myocardial regenerative repair by affecting plasmalogen metabolism. Further, we find that PEX3-regulated plasmalogen activates the AKT/GSK3β signaling pathway via the plasma membrane localization of ITGB3. Our study indicates that PEX3 may represent a novel therapeutic target for myocardial regenerative repair following injury.
Topics: Animals; Mice; Mice, Knockout; Integrin beta3; Cell Membrane; Regeneration; Myocytes, Cardiac; Male; Plasmalogens; Signal Transduction; Myocardium; Mice, Inbred C57BL; Heart Injuries; Cell Proliferation; Membrane Proteins
PubMed: 38951640
DOI: 10.1038/s42003-024-06483-0 -
Communications Biology Jun 2024Transport of macromolecules through the nuclear envelope (NE) is mediated by nuclear pore complexes (NPCs) consisting of nucleoporins (Nups). Elys/Mel-28 is the Nup that...
Transport of macromolecules through the nuclear envelope (NE) is mediated by nuclear pore complexes (NPCs) consisting of nucleoporins (Nups). Elys/Mel-28 is the Nup that binds and connects the decondensing chromatin with the reassembled NPCs at the end of mitosis. Whether Elys links chromatin with the NE during interphase is unknown. Here, using DamID-seq, we identified Elys binding sites in Drosophila late embryos and divided them into those associated with nucleoplasmic or with NPC-linked Elys. These Elys binding sites are located within active or inactive chromatin, respectively. Strikingly, Elys knockdown in S2 cells results in peripheral chromatin displacement from the NE, in decondensation of NE-attached chromatin, and in derepression of genes within. It also leads to slightly more compact active chromatin regions. Our findings indicate that NPC-linked Elys, together with the nuclear lamina, anchors peripheral chromatin to the NE, whereas nucleoplasmic Elys decompacts active chromatin.
Topics: Animals; Chromatin; Interphase; Drosophila Proteins; Nuclear Pore; Nuclear Pore Complex Proteins; Drosophila melanogaster; Cell Nucleus; Binding Sites
PubMed: 38951619
DOI: 10.1038/s42003-024-06495-w -
Nature Communications Jun 2024Like many other viruses, KSHV has two life cycle modes: the latent phase and the lytic phase. The RTA protein from KSHV is essential for lytic reactivation, but how this...
Like many other viruses, KSHV has two life cycle modes: the latent phase and the lytic phase. The RTA protein from KSHV is essential for lytic reactivation, but how this protein's activity is regulated is not fully understood. Here, we report that linear ubiquitination regulates the activity of RTA during KSHV lytic reactivation and de novo infection. Overexpressing OTULIN inhibits KSHV lytic reactivation, whereas knocking down OTULIN or overexpressing HOIP enhances it. Intriguingly, we found that RTA is linearly polyubiquitinated by HOIP at K516 and K518, and these modifications control the RTA's nuclear localization. OTULIN removes linear polyubiquitin chains from cytoplasmic RTA, preventing its nuclear import. The RTA orthologs encoded by the EB and MHV68 viruses are also linearly polyubiquitinated and regulated by OTULIN. Our study establishes that linear polyubiquitination plays a critically regulatory role in herpesvirus infection, adding virus infection to the list of biological processes known to be controlled by linear polyubiquitination.
Topics: Herpesvirus 8, Human; Ubiquitination; Humans; Virus Replication; Immediate-Early Proteins; HEK293 Cells; Trans-Activators; Ubiquitin-Protein Ligases; Virus Activation; Herpesviridae Infections; Cell Nucleus
PubMed: 38951495
DOI: 10.1038/s41467-024-49887-6