Park, S;Dahn, R;Kurt, E;Presle, A;VandenHeuvel, K;Moravec, C;Jambhekar, A;Olukoga, O;Shepherd, J;Echard, A;Blower, M;Skop, A;
| DOI: 10.2139/ssrn.4318824
The midbody (MB) is a transient structure at the spindle midzone that is required for cytokinesis, the terminal stage of cell division. Long ignored as a vestigial remnant of cytokinesis, we now know MBs are released post-abscission as extracellular vesicles called MB remnants (MBRs) and can modulate cell proliferation, fate decisions, tissue polarity, neuronal architecture, and tumorigenic behavior. Here, we demonstrate that the MB matrix—the structurally amorphous MB core of unknown composition—is the site of ribonucleoprotein assembly and is enriched in mRNAs that encode proteins involved in cell fate, oncogenesis, and pluripotency, that we are calling the MB granule. Using a quantitative transcriptomic approach, we identified a population of mRNAs enriched in mitotic MBs and confirmed their presence in signaling MBR vesicles released by abscission. The MB granule is unique in that it is translationally active, contains both small and large ribosomal subunits, and has both membrane-less and membranebound states. Both MBs and post-abscission MBRs are sites of spatiotemporally regulated translation, which is initiated when nascent daughter cells re-enter G1 and continues after extracellular release. We demonstrate that the MB is the assembly site of an RNP granule. MKLP1 and ARC are necessary for the localization and translation of RNA in the MB dark zone, whereas ESCRT-III was necessary to maintain translation levels in the MB. Our data suggest a model in which the MB functions as a novel RNA-based organelle with a uniquely complex life cycle. We present a model in which the assembly and transfer of RNP complexes are central to post-mitotic MBR function and suggest the MBR serves as a novel mode of RNA-based intercellular communication with a defined biogenesis that is coupled to abscission, and inherently links cell division status with signaling capacity. To our knowledge, this is the first example of an autonomous extracellular vesicle with active translation activity.
Clinical and translational medicine
Liu, L;Hu, L;Long, H;Zheng, M;Hu, Z;He, Y;Gao, X;Du, P;Zhao, H;Yu, D;Lu, Q;Zhao, M;
PMID: 36447054 | DOI: 10.1002/ctm2.1117
The aberrant differentiation of T follicular helper (Tfh) cells plays an important role in the pathogenesis of systemic lupus erythematosus (SLE). However, the mechanism of regulating Tfh cells differentiation remains unclear. Long noncoding RNAs (lncRNAs) act as important regulators in the processes of innate and adaptive immune response. Whether lncRNAs are involved in regulating Tfh cell differentiation and autoimmune responses need to be further identified.The characters and functions of human IL21-AS1 and its mouse homologous lncRNA (mIl21-AS) were investigated by a series of biochemical assays and cell transfection assay. mIl21-AS1 regulating humoral immune response in vivo was explored by keyhole limpet haemocyanin (KLH) and chronic graft versus host disease (cGVHD) model.Human IL21-AS1 and its mouse homologous lncRNA (mIl21-AS) were identified and cloned. We uncovered that IL21-AS1 was highly expressed in CD4+ T cells of SLE patients and Tfh cells, which promoted differentiation of Tfh cells. Mechanistically, IL21-AS1 bound heterogeneous nuclear ribonucleoprotein U and recruited acetyltransferases CREB-binding protein to the promoter of IL21, leading to the transcriptional activation of IL21 and Tfh cells differentiation through increasing Histone H3 acetylation level on IL21 promoter. Moreover, Tfh proportion and antibodies production were significantly increased in mIl21-AS knock-in mice immunized with KLH. mIl21-AS1 overexpression also exacerbated the lupus-like phenotype in cGVHD mice model.Our results demonstrate that IL21-AS1 activates IL21 transcription via epigenetic mechanism to promote germinal centre response, adding insight into the molecular regulation of autoimmune pathogenesis and providing a novel target for SLE treatment.
Schuh, AJ;Amman, BR;Guito, JC;Graziano, JC;Sealy, TK;Kirejczyk, SGM;Towner, JS;
PMID: 36463252 | DOI: 10.1038/s41598-022-24673-w
The human-pathogenic Kasokero virus (KASV; genus Orthonairovirus) has been isolated from the sera of Egyptian rousette bats (ERBs; Rousettus aegyptiacus) captured in Uganda and unengorged Ornithodoros (Reticulinasus) faini ticks collected from the rock crevices of ERB colonies in South Africa and Uganda. Although evidence suggests that KASV is maintained in an enzootic transmission cycle between O. (R.) faini ticks and ERBs with potential for incidental virus spillover to humans through the bite of an infected tick, the vertebrate reservoir status of ERBs for KASV has never been experimentally evaluated. Furthermore, the potential for bat-to-bat and bat-to-human transmission of KASV is unknown. Herein, we inoculate two groups of ERBs with KASV; one group of bats is serially sampled to assess viremia, oral, fecal, and urinary shedding and the second group of bats is serially euthanized to assess virus-tissue tropism. Throughout the study, none of the bats exhibit overt signs of clinical disease. Following the detection of high KASV loads of long duration in blood, oral, fecal, and urine specimens collected from ERBs in the serial sampling group, all bats seroconvert to KASV. ERBs from the serial euthanasia group exhibit high KASV loads indicative of virus replication in the skin at the inoculation site, spleen, and inguinal lymph node tissue, and histopathology and in situ hybridization reveal virus replication in the liver and self-limiting, KASV-induced lymphohistiocytic hepatitis. The results of this study suggest that ERBs are competent, natural vertebrate reservoir hosts for KASV that can sustain viremias of appropriate magnitude and duration to support virus maintenance through bat-tick-bat transmission cycles. Viral shedding data suggests that KASV might also be transmitted bat-to-bat and highlights the potential for KASV spillover to humans through contact with infectious oral secretions, feces, or urine.
Néphrologie & Thérapeutique
Dejucq-Rainsford, N;Robinet, G;Satie, A;Aubry, F;Rioux-Leclercq, N;Lavoué, V;Vigneau, C;Mazaud-Guittot, S;
| DOI: 10.1016/j.nephro.2022.07.200
Introduction Le virus ZIKA (ZIKV) est un virus transmis par les moustiques et par le sperme, avec un fort potentiel d’émergence. Lors d’une infection pendant la grossesse, ce virus peut entraîner des anomalies fœtales cérébrales mais aussi uro-génitales, comme révélé lors de l’épidémie de 2015-2016 dans les Amériques. Description L’objectif de notre étude est de déterminer la permissivité du rein fœtal au ZIKV et les conséquences de cette infection. Méthodes Pour cela nous avons infecté ex vivo avec ZIKV des cultures organotypiques de reins fœtaux disséqués à partir de produits d’IVG obtenus entre 11 et 14 semaines d’aménorrhée. Résultats Nos résultats montrent que le ZIKV se réplique efficacement dans le rein fœtal, comme attesté par l’augmentation de l’ARN viral dans les cultures au cours du temps et par la détection in situ en RNAscope de l’ARN brin négatif produit lors de la réplication du virus. L’ARN réplicatif du ZIKV a été retrouvé dans le tissu interstitiel ainsi que dans des tubules et des glomérules en formation. Les cellules cibles du virus ont été identifiées par immunohistochimie à l’aide d’anticorps contre la protéine virale non structurale NS2b et contre des marqueurs cellulaires. Le virus est retrouvé au niveau du compartiment interstitiel dans des macrophages CD68+ et des fibroblastes SMA+ et au niveau des cellules épithéliales tubulaires CK18+. La localisation dans des cellules glomérulaires WT1+ reste à déterminer. L’infection virale n’a pas d’effet délétère majeur sur la morphologie, la viabilité et la prolifération cellulaire du rein à 6 jours post-infection. Conclusion En conclusion, ces résultats révèlent pour la première fois que le rein fœtal est permissif au virus Zika. Il serait nécessaire d’évaluer l’effet à plus long terme de l’infection sur le rein en développement. Notre modèle ex vivo pourrait permettre de tester l’efficacité d’antiviraux visant à empêcher la réplication du ZIKV dans le rein foetal.
Journal of hematology & oncology
Zhang, T;Xia, W;Song, X;Mao, Q;Huang, X;Chen, B;Liang, Y;Wang, H;Chen, Y;Yu, X;Zhang, Z;Yang, W;Xu, L;Dong, G;Jiang, F;
PMID: 35982471 | DOI: 10.1186/s13045-022-01331-2
Lung adenocarcinoma (LUAD) is the leading cause of death worldwide. However, the roles of long noncoding RNAs (lncRNAs) hijacked by super-enhancers (SEs), vital regulatory elements of the epigenome, remain elusive in the progression of LUAD metastasis.SE-associated lncRNA microarrays were used to identify the dysregulated lncRNAs in LUAD. ChIP-seq, Hi-C data analysis, and luciferase reporter assays were utilized to confirm the hijacking of LINC01977 by SE. The functions and mechanisms of LINC01977 in LUAD were explored by a series of in vitro and in vivo assays.We found that LINC01977, a cancer-testis lncRNA, was hijacked by SE, which promoted proliferation and invasion both in vitro and in vivo. LINC01977 interacted with SMAD3 to induce its nuclear transport, which facilitated the interaction between SMAD3 and CBP/P300, thereby regulating the downstream target gene ZEB1. Additionally, SMAD3 up-regulated LINC09177 transcription by simultaneously binding the promoter and SE, which was induced by the infiltration of M2-like tumor-associated macrophages (TAM2), subsequently activating the TGF-β/SMAD3 pathway. Moreover, LINC01977 expression was positively correlated with TAM2 infiltration and SMAD3 expression, especially in early-stage LUAD. Higher chromatin accessibility in the SE region of LINC01977 was observed with high expression of TGF-β. Early-stage LUAD patients with high LIN01977 expression had a shorter disease-free survival.TAM2 infiltration induced a rich TGF-β microenvironment, activating SMAD3 to bind the promoter and the SE of LINC01977, which up-regulated LINC01977 expression. LINC01977 also promoted malignancy via the canonical TGF-β/SMAD3 pathway. LINC01977 hijacked by SE could be a valuable therapeutic target, especially for the treatment of early-stage LUAD.
Ribeiro, M;Ayupe, AC;Beckedorff, FC;Levay, K;Rodriguez, S;Tsoulfas, P;Lee, JK;Nascimento-Dos-Santos, G;Park, KK;
PMID: 35738417 | DOI: 10.1016/j.expneurol.2022.114147
Following injury in the central nervous system, a population of astrocytes occupy the lesion site, form glial bridges and facilitate axon regeneration. These astrocytes originate primarily from resident astrocytes or NG2+ oligodendrocyte progenitor cells. However, the extent to which these cell types give rise to the lesion-filling astrocytes, and whether the astrocytes derived from different cell types contribute similarly to optic nerve regeneration remain unclear. Here we examine the distribution of astrocytes and NG2+ cells in an optic nerve crush model. We show that optic nerve astrocytes partially fill the injury site over time after a crush injury. Viral mediated expression of a growth-promoting factor, ciliary neurotrophic factor (CNTF), in retinal ganglion cells (RGCs) promotes axon regeneration without altering the lesion size or the degree of lesion-filling GFAP+ cells. Strikingly, using inducible NG2CreER driver mice, we found that CNTF overexpression in RGCs increases the occupancy of NG2+ cell-derived astrocytes in the optic nerve lesion. An EdU pulse-chase experiment shows that the increase in NG2 cell-derived astrocytes is not due to an increase in cell proliferation. Lastly, we performed RNA-sequencing on the injured optic nerve and reveal that CNTF overexpression in RGCs results in significant changes in the expression of distinct genes, including those that encode chemokines, growth factor receptors, and immune cell modulators. Even though CNTF-induced axon regeneration has long been recognized, this is the first evidence of this procedure affecting glial cell fate at the optic nerve crush site. We discuss possible implication of these results for axon regeneration.
Journal of molecular and cellular cardiology
Ding, S;Liu, J;Han, X;Ding, W;Liu, Z;Zhu, Y;Zhan, W;Wan, Y;Gai, S;Hou, J;Wang, X;Wu, Y;Wu, A;Li, CY;Zheng, Z;Tian, XL;Cao, H;
PMID: 35714558 | DOI: 10.1016/j.yjmcc.2022.06.001
Long noncoding RNAs (lncRNAs) are critical regulators of inflammation with great potential as new therapeutic targets. However, the role of lncRNAs in early atherosclerosis remains poorly characterized. This study aimed to identify the key lncRNA players in activated endothelial cells (ECs). The lncRNAs in response to pro-inflammatory factors in ECs were screened through RNA sequencing. ICAM-1-related non-coding RNA (ICR) was identified as the most potential candidate for early atherosclerosis. ICR is essential for intercellular adhesion molecule-1 (ICAM1) expression, EC adhesion and migration. In a high fat diet-induced atherosclerosis model in mice, ICR is upregulated in the development of atherosclerosis. After intravenous injection of adenovirus carrying shRNA for mouse ICR, the atherosclerotic plaque area was markedly reduced with the declined expression of ICR and ICAM1. Mechanistically, ICR stabilized the mRNA of ICAM1 in quiescent ECs; while under inflammatory stress, ICR upregulated ICAM1 in a nuclear factor kappa B (NF-κB) dependent manner. RNA-seq analysis showed pro-inflammatory targets of NF-κB were regulated by ICR. Furthermore, the chromatin immunoprecipitation assays showed that p65 binds to ICR promoter and facilitates its transcription. Interestingly, ICR, in turn, promotes p65 accumulation and activity, forming a positive feedback loop to amplify NF-κB signaling. Preventing the degradation of p65 using proteasome inhibitors rescued the expression of NF-κB targets suppressed by ICR. Taken together, ICR acts as an accelerator to amplify NF-κB signaling in activated ECs and suppressing ICR is a promising early intervention for atherosclerosis through ICR/p65 loop blockade.
Frontiers in microbiology
Yang, Y;Li, M;Ma, Y;Ye, W;Si, Y;Zheng, X;Liu, H;Cheng, L;Zhang, L;Zhang, H;Zhang, X;Lei, Y;Shen, L;Zhang, F;Ma, H;
PMID: 35495674 | DOI: 10.3389/fmicb.2022.849020
As the global prototypical zoonotic hantavirus, Hantaan virus (HTNV) is prevalent in Asia and is the leading causative agent of severe hemorrhagic fever with renal syndrome (HFRS), which has profound morbidity and mortality. Macrophages are crucial components of the host innate immune system and serve as the first line of defense against HTNV infection. Previous studies indicated that the viral replication efficiency in macrophages determines hantavirus pathogenicity, but it remains unknown which factor manipulates the macrophage activation pattern and the virus-host interaction process. Here, we performed the transcriptomic analysis of HTNV-infected mouse bone marrow-derived macrophages and identified the long noncoding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1), especially the isoform NEAT1-2, as one of the lncRNAs that is differentially expressed at the early phase. Based on coculture experiments, we revealed that silencing NEAT1-2 hinders inflammatory macrophage activation and facilitates HTNV propagation, while enhancing NEAT1-2 transcription effectively restrains viral replication. Furthermore, sterol response element binding factor-2 (SREBP2), which controls the cholesterol metabolism process, was found to stimulate macrophages by promoting the production of multiple inflammatory cytokines upon HTNV infection. NEAT1-2 could potentiate SREBP2 activity by upregulating Srebf1 expression and interacting with SREBP2, thus stimulating inflammatory macrophages and limiting HTNV propagation. More importantly, we demonstrated that the NEAT1-2 expression level in patient monocytes was negatively correlated with viral load and HFRS disease progression. Our results identified a function and mechanism of action for the lncRNA NEAT1 in heightening SREBP2-mediated macrophage activation to restrain hantaviral propagation and revealed the association of NEAT1 with HFRS severity.
Computational intelligence and neuroscience
Zhao, Y;Yan, G;Mi, J;Wang, G;Yu, M;Jin, D;Tong, X;Wang, X;
PMID: 35528328 | DOI: 10.1155/2022/8400106
Long noncoding RNA (lncRNA) is involved in the occurrence and development of diabetic kidney disease (DKD). It is necessary to identify the expression of lncRNA from DKD patients through systematic reviews, and then carry out silico analyses to recognize the dysregulated lncRNA and their associated pathways.The study searched Pubmed, Embase, Cochrane Library, WanFang, VIP, CNKI, and CBM to find lncRNA studies on DKD published before March 1, 2021. Systematic review of the literature on this topic was conducted to determine the expression of lncRNA in DKD and non-DKD controls. For the dysregulated lncRNA in DKD patients, silico analysis was performed, and lncRNA2Target v2.0 and starBase were used to search for potential target genes of lncRNA. The Encyclopedia of Genomics (KEGG) pathway enrichment analysis was performed to better identify dysregulated lncRNAs in DKD and determine the associated signal pathways.According to the inclusion and exclusion criteria, 28 publications meeting the eligibility criteria were included in the systematic evaluation. A total of 3,394 patients were enrolled in this study, including 1,238 patients in DKD group, and 1,223 diabetic patients, and 933 healthy adults in control group. Compared with the control, there were eight lncRNA disorders in DKD patients (MALAT1, GAS5, MIAT, CASC2, NEAT1, NR_033515, ARAP1-AS2, and ARAP1-AS1). In addition, five lncRNAs (MALAT1, GAS5, MIAT, CASC2, and NEAT1) participated in disease-related signal pathways, indicating their role in DKD. Discussion. This study showed that there were eight lncRNAs in DKD that were persistently dysregulated, especially five lncRNAs which were closely related to the disease. Although systematic review included 28 studies that analyzed the expression of lncRNA in DKD-related tissues, the potential of these dysregulated lncRNAs as biomarkers or therapeutic targets for DKD remains to be further explored. Trial registration. PROSPERO (CRD42021248634).
Wasala, NB;Million, ED;Watkins, TB;Wasala, LP;Han, J;Yue, Y;Lu, B;Chen, SJ;Hakim, CH;Duan, D;
PMID: 35350865 | DOI: 10.1089/hum.2021.130
Adeno-associated virus (AAV)-mediated clustered regularly interspaced short palindromic repeats (CRISPR) editing holds promise to restore missing dystrophin in Duchenne muscular dystrophy (DMD). Intramuscular coinjection of CRISPR-associated protein 9 (Cas9) and guide RNA (gRNA) vectors resulted in robust dystrophin restoration in short-term studies in the mdx mouse model of DMD. Intriguingly, this strategy failed to yield efficient dystrophin rescue in muscle in a long-term (18-month) systemic injection study. In-depth analyses revealed a selective loss of the gRNA vector after long-term systemic, but not short-term local injection. To determine whether preferential gRNA vector depletion is due to the mode of delivery (local vs. systemic) or the duration of the study (short term vs. long term), we conducted a short-term systemic injection study. The gRNA (4e12 vg/mouse in the 1:1 group or 1.2e13 vg/mouse in the 3:1 group) and Cas9 (4e12 vg/mouse) vectors were coinjected intravenously into 4-week-old mdx mice. The ratio of the gRNA to Cas9 vector genome copy dropped from 1:1 and 3:1 at injection to 0.4:1 and 1:1 at harvest 3 months later, suggesting that the route of administration, rather than the experimental duration, determines preferential gRNA vector loss. Consistent with our long-term systemic injection study, the vector ratio did not influence Cas9 expression. However, the 3:1 group showed significantly higher dystrophin expression and genome editing, better myofiber size distribution, and a more pronounced improvement in muscle function and electrocardiography. Our data suggest that the gRNA vector dose determines the outcome of systemic AAV CRISPR therapy for DMD.
Schmitz, MT;Sandoval, K;Chen, CP;Mostajo-Radji, MA;Seeley, WW;Nowakowski, TJ;Ye, CJ;Paredes, MF;Pollen, AA;
PMID: 35322231 | DOI: 10.1097/PAI.0000000000001013
Neuroanatomists have long speculated that expanded primate brains contain an increased morphological diversity of inhibitory neurons (INs)1, and recent studies have identified primate-specific neuronal populations at the molecular level2. However, we know little about the developmental mechanisms that specify evolutionarily novel cell types in the brain. Here, we reconstruct gene expression trajectories specifying INs generated throughout the neurogenic period in macaques and mice by analysing the transcriptomes of 250,181 cells. We find that the initial classes of INs generated prenatally are largely conserved among mammals. Nonetheless, we identify two contrasting developmental mechanisms for specifying evolutionarily novel cell types during prenatal development. First, we show that recently identified primate-specific TAC3 striatal INs are specified by a unique transcriptional programme in progenitors followed by induction of a distinct suite of neuropeptides and neurotransmitter receptors in new-born neurons. Second, we find that multiple classes of transcriptionally conserved olfactory bulb (OB)-bound precursors are redirected to expanded primate white matter and striatum. These classes include a novel peristriatal class of striatum laureatum neurons that resemble dopaminergic periglomerular cells of the OB. We propose an evolutionary model in which conserved initial classes of neurons supplying the smaller primate OB are reused in the enlarged striatum and cortex. Together, our results provide a unified developmental taxonomy of initial classes of mammalian INs and reveal multiple developmental mechanisms for neural cell type evolution.
Li, X;Tian, BM;Deng, DK;Liu, F;Zhou, H;Kong, DQ;Qu, HL;Sun, LJ;He, XT;Chen, FM;
PMID: 35296649 | DOI: 10.1038/s41413-022-00197-x
Periodontal ligament stem cells (PDLSCs) are a key cell type for restoring/regenerating lost/damaged periodontal tissues, including alveolar bone, periodontal ligament and root cementum, the latter of which is important for regaining tooth function. However, PDLSCs residing in an inflammatory environment generally exhibit compromised functions, as demonstrated by an impaired ability to differentiate into cementoblasts, which are responsible for regrowing the cementum. This study investigated the role of mitochondrial function and downstream long noncoding RNAs (lncRNAs) in regulating inflammation-induced changes in the cementogenesis of PDLSCs. We found that the inflammatory cytokine-induced impairment of the cementogenesis of PDLSCs was closely correlated with their mitochondrial function, and lncRNA microarray analysis and gain/loss-of-function studies identified GACAT2 as a regulator of the cellular events involved in inflammation-mediated mitochondrial function and cementogenesis. Subsequently, a comprehensive identification of RNA-binding proteins by mass spectrometry (ChIRP-MS) and parallel reaction monitoring (PRM) assays revealed that GACAT2 could directly bind to pyruvate kinase M1/2 (PKM1/2), a protein correlated with mitochondrial function. Further functional studies demonstrated that GACAT2 overexpression increased the cellular protein expression of PKM1/2, the PKM2 tetramer and phosphorylated PKM2, which led to enhanced pyruvate kinase (PK) activity and increased translocation of PKM2 into mitochondria. We then found that GACAT2 overexpression could reverse the damage to mitochondrial function and cementoblastic differentiation of PDLSCs induced by inflammation and that this effect could be abolished by PKM1/2 knockdown. Our data indicated that by binding to PKM1/2 proteins, the lncRNA GACAT2 plays a critical role in regulating mitochondrial function and cementogenesis in an inflammatory environment.