Chan, SN;Pek, JW;
PMID: 36533631 | DOI: 10.15252/embr.202154350
Stable intronic sequence RNAs (sisRNAs) are stable, long noncoding RNAs containing intronic sequences. While sisRNAs have been found across diverse species, their level of conservation remains poorly understood. Here we report that the biogenesis and functions of a sisRNA transcribed from the highly conserved Arglu1 locus are distinct in human and Drosophila melanogaster. The Arglu1 genes in both species show similar exon-intron structures where the intron 2 is orthologous and positionally conserved. In humans, Arglu1 sisRNA retains the entire intron 2 and promotes host gene splicing. Mechanistically, Arglu1 sisRNA represses the splicing-inhibitory activity of ARGLU1 protein by binding to ARGLU1 protein and promoting its localization to nuclear speckles, away from the Arglu1 gene locus. In contrast, Drosophila dArglu1 sisRNA forms via premature cleavage of intron 2 and represses host gene splicing. This repression occurs through a local accumulation of dARGLU1 protein and inhibition of telescripting by U1 snRNPs at the dArglu1 locus. We propose that distinct biogenesis of positionally conserved Arglu1 sisRNAs in both species may have led to functional divergence.
Wang, B;Jiang, B;Li, GW;Dong, F;Luo, Z;Cai, B;Wei, M;Huang, J;Wang, K;Feng, X;Tong, F;Wang, S;Wang, Q;Han, Q;Li, C;Zhang, X;Yang, L;Bao, L;
PMID: 36524339 | DOI: 10.15252/embr.202154313
Somatosensory neurons are highly heterogeneous with distinct types of neural cells responding to specific stimuli. However, the distribution and roles of cell-type-specific long intergenic noncoding RNAs (lincRNAs) in somatosensory neurons remain largely unexplored. Here, by utilizing droplet-based single-cell RNA-seq (scRNA-seq) and full-length Smart-seq2, we show that lincRNAs, but not coding mRNAs, are enriched in specific types of mouse somatosensory neurons. Profiling of lincRNAs from single neurons located in dorsal root ganglia (DRG) identifies 200 lincRNAs localized in specific types or subtypes of somatosensory neurons. Among them, the conserved cell-type-specific lincRNA CLAP associates with pruritus and is abundantly expressed in somatostatin (SST)-positive neurons. CLAP knockdown reduces histamine-induced Ca2+ influx in cultured SST-positive neurons and in vivo reduces histamine-induced scratching in mice. In vivo knockdown of CLAP also decreases the expression of neuron-type-specific and itch-related genes in somatosensory neurons, and this partially depends on the RNA binding protein MSI2. Our data reveal a cell-type-specific landscape of lincRNAs and a function for CLAP in somatosensory neurons in sensory transmission.
Gala, DS;Titlow, JS;Teodoro, RO;Davis, I;
PMID: 36442969 | DOI: 10.1261/rna.079422.122
Neurons and glia are highly polarized cells, whose distal cytoplasmic functional subdomains require specific proteins. Neurons have axonal and dendritic cytoplasmic extensions containing synapses requiring mRNA transport and localized translation to regulate synaptic plasticity efficiently. The principles behind these mechanisms are equally attractive for explaining rapid local regulation of distal glial cytoplasmic projections, independent of their cell nucleus. However, in contrast to neurons, this topic has received little experimental attention in glia. Nevertheless, there are many functionally diverse glial sub-types, containing extensive networks of long cytoplasmic projections with likely localized regulation that influence neurons and their synapses. Moreover, glia have many other neuron-like properties, including electrical activity, secretion of gliotransmitters and calcium signaling, influencing for example synaptic transmission, plasticity and axon pruning. Here, we review previous studies concerning glial transcripts with important roles in influencing synaptic plasticity, focusing on a few cases involving localized translation. We discuss a variety of important questions about mRNA transport and localized translation in glia that remain to be addressed using cutting-edge tools already available for neurons.
Hernandez, S;Serrano, AG;Solis Soto, LM;
PMID: 35751462 | DOI: 10.1002/adbi.202200046
The importance of neurons and nerve fibers in the tumor microenvironment (TME) of solid tumors is now acknowledged after being unexplored for a long time; this is possible due to the development of new technologies that allow in situ characterization of the TME. Recent studies have shown that the density and types of nerves that innervate tumors can predict a patient's clinical outcome and drive several processes of tumor biology. Nowadays, several efforts in cancer research and neuroscience are taking place to elucidate the mechanisms that drive tumor-associated innervation and nerve-tumor and nerve-immune interaction. Assessment of neurons and nerves within the context of the TME can be performed in situ, in tumor tissue, using several pathology-based strategies that utilize histochemical and immunohistochemistry principles, hi-plex technologies, and computational pathology approaches to identify measurable histopathological characteristics of nerves. These features include the number and type of tumor associated nerves, topographical location and microenvironment of neural invasion of malignant cells, and investigation of neuro-related biomarker expression in nerves, tumor cells, and cells of the TME. A deeper understanding of these complex interactions and the impact of nerves in tumor biology will guide the design of better strategies for targeted therapy in clinical trials.
McQueen, L;Ladak, S;Tavares, A;Murphy, G;Zakkar, M;
| DOI: 10.1136/heartjnl-2022-bcs.200
BACKGROUND The long saphenous vein (LSV) is commonly utilised in CABG surgery to facilitate revascularisation. However, over time these grafts develop intimal hyperplasia (IH) and accelerated atherosclerosis, leading to stenosis and occlusion. A common feature of IH is vascular calcification (VC) within the affected vessel. Recently, the matricellular protein osteopontin (OPN) has been implicated in this process at endothelial injury sites in porcine models, but this has not been expanded to humans. Consecutively, studies have implicated the arterial haemodynamic environment as a major driver of the pro-inflammatory conditions facilitating VC and IH. As such, treatment with a synthetic glucocorticoid, dexamethasone, which has proven beneficial in inhibiting IH in murine models, may beneficially modulate this process in humans. This work aims to assess the role of OPN on VC and IH in an ex vivo model, whether dexamethasone can modulate this process, and whether detection of VC in situ can act as a novel clinical monitoring approach to graft patency.
Development (Cambridge, England)
Hoyle, DJ;Dranow, DB;Schilling, TF;
PMID: 34919126 | DOI: 10.1242/dev.199826
Secreted signals in patterning systems often induce repressive signals that shape their distributions in space and time. In developing growth plates (GPs) of endochondral long bones, Parathyroid hormone-like hormone (Pthlh) inhibits Indian hedgehog (Ihh) to form a negative-feedback loop that controls GP progression and bone size. Whether similar systems operate in other bones and how they arise during embryogenesis remain unclear. We show that Pthlha expression in the zebrafish craniofacial skeleton precedes chondrocyte differentiation and restricts where cells undergo hypertrophy, thereby initiating a future GP. Loss of Pthlha leads to an expansion of cells expressing a novel early marker of the hypertrophic zone (HZ), entpd5a, and later HZ markers, such as ihha, whereas local Pthlha misexpression induces ectopic entpd5a expression. Formation of this early pre-HZ correlates with onset of muscle contraction and requires mechanical force; paralysis leads to loss of entpd5a and ihha expression in the pre-HZ, mislocalized pthlha expression and no subsequent ossification. These results suggest that local Pthlh sources combined with force determine HZ locations, establishing the negative-feedback loop that later maintains GPs.
Journal of Swine Health and Production
Buckley, A;Lager, K;
| DOI: 10.54846/jshap/1270
Senecavirus A (SVA) has been demonstrated to be a causative agent for vesicular disease in swine. It is clinically indistinguishable from other agents that cause vesicular disease such as foot-and-mouth disease virus (FMDV), which is a reportable foreign animal disease (FAD). Thus, an investigation is initiated to rule out FMDV every time a vesicle is observed. Senecavirus A has now been reported across the Americas and Asia, and it appears the ecology of this virus has changed from sporadic infections to an endemic disease in some areas. In addition to vesicular disease, there have also been reports of increased neonatal mortality on affected sow farms. Knowledge about the pathogenesis of SVA in swine can provide many benefits to the swine industry. Understanding how long the virus can be detected in various sample types after infection can aide in choosing the correct samples to collect for diagnosis. In addition, the duration of virus shedding can help determine measures to control virus spread between animals. Prevention of SVA infection and disease with an efficacious vaccine could improve swine welfare, minimize SVA transmission, and reduce the burden of FAD investigations.
Molecular therapy : the journal of the American Society of Gene Therapy
Fang, F;Zhuang, P;Feng, X;Liu, P;Liu, D;Huang, H;Li, L;Chen, W;Liu, L;Sun, Y;Jiang, H;Ye, J;Hu, Y;
PMID: 35114390 | DOI: 10.1016/j.ymthe.2022.01.035
The lack of neuroprotective treatments for retinal ganglion cells (RGCs) and optic nerve (ON) is a central challenge for glaucoma management. Emerging evidence suggests that redox factor NAD+ decline is a hallmark of aging and neurodegenerative diseases. Supplementation with NAD+ precursors and overexpression of NMNAT1, the key enzyme in the NAD+ biosynthetic process, have significant neuroprotective effects. We first profile the translatomes of RGCs in naive mice and mice with silicone oil-induced ocular hypertension (SOHU)/glaucoma by RiboTag mRNA sequencing. Intriguingly, only NMNAT2, but not NMNAT1 or NMNAT3, is significantly decreased in SOHU glaucomatous RGCs, which we confirm by in situ hybridization. We next demonstrate that AAV2 intravitreal injection-mediated overexpression of long half-life NMNAT2 mutant driven by RGC-specific mouse γ-synuclein (mSncg) promoter restores decreased NAD+ levels in glaucomatous RGCs and ONs. Moreover, this RGC-specific gene therapy strategy delivers significant neuroprotection of both RGC soma and axon and preservation of visual function in the traumatic ON crush model and the SOHU glaucoma model. Collectively, our studies suggest that the weakening of NMNAT2 expression in glaucomatous RGCs contributes to a deleterious NAD+ decline, and that modulating RGC-intrinsic NMNAT2 levels by AAV2-mSncg vector is a promising gene therapy for glaucomatous neurodegeneration.
International journal of surgical pathology
Kropivšek, L;Pižem, J;Mavčič, B;
PMID: 35098753 | DOI: 10.1177/10668969221076545
Giant cell tumor of bone (GCTB) and tenosynovial giant cell tumor (TGCT) share misleadingly similar names, soft texture and brown color macroscopically, osteoclast-like multinucleated giant cells microscopically and localisation in the musculoskeletal system. However, these two tumor types are biologically and clinically two distinct entities with different natural courses of progression and considerably different modes of surgical and medical treatment. In this article, we provide a detailed update on the similarities and the differences between both tumor types.GCTB is a locally aggressive osteolytic bone tumor, commonly seen in patients in their third decade of life. It usually occurs as a solitary lesion in the meta-epiphyseal region of long bones. It can be diagnosed using plain radiographic imaging, CT radiography or MRI to estimate the tumor extent, soft tissue and joint involvement. GCTB is usually treated with intralesional excision by curettage. Systemically, it can be treated with bisphosphonates and denosumab or radiotherapy.TGCT is a rare, slowly progressing tumor of synovial tissue, affecting the joint, tendon sheath or bursa, mostly seen in middle-aged patients. TGCT is usually not visible on radiographs and MRI is mostly used to enable assessment of potential bone involvement and distinguishing between two TGCT types. Localised TGCT is mostly treated with marginal surgical resection, while diffuse TGCT is optimally treated with total synovectomy and is more difficult to remove. Additionally, radiotherapy, intraarticular injection of radioactive isotopes, anti-TNF-α antibodies and targeted medications may be used.
Webb, A;Schindell, B;Griffin, B;Soule, G;Siddik, A;Abrenica, B;Memon, H;Su, R;Kobasa, D;Safronetz, D;Kindrachuk, J;
| DOI: 10.2139/ssrn.4000892
Recent outbreaks of Ebola virus linked to chains of transmission from the 2014-2016 West African Ebola virus epidemic suggest a new paradigm for persistent Ebola virus infections as a lasting concern to public health. Cases of Ebola virus disease linked to sexual transmission and detection of Ebola virus in the male reproductive tract long after patients have recovered suggests that Ebola virus persistence occurs in this immune privileged area. However, little is known about Ebola virus cell tropism, viral kinetics, and host response to infection in the testis. In this study, we challenged immunocompromised mice and testicular tissue cultures with wild type Ebola virus. We utilized RT-qPCR and ISH to detect and quantify Ebola virus in the testis. We also employed RNAseq analysis to measure the transcriptomic response of specific testicular cell types to Ebola virus infection. Our results indicate that Ebola virus productively infects the cells at the blood-testis barrier, and that the interstitial space is more susceptible to infection compared to blood-testis barrier itself. In addition, the Sertoli cells that make up the physical structure of the blood-testis barrier maintain greater viability during Ebola virus infection, and this results from nonstandard immune response that prioritizes inhibited viral entry/replication and increased cell homeostatic activity. Our findings reinforce the need to further investigate viral persistence in the male reproductive tract as a reservoir for ongoing and future outbreaks of Ebola virus disease.
Recovery of Latent HIV-1 from Brain Tissue by Adoptive Cell Transfer in Virally Suppressed Humanized Mice
Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology
Su, H;Sravanam, S;Sillman, B;Waight, E;Makarov, E;Mathews, S;Poluektova, LY;Gorantla, S;Gendelman, HE;Dash, PK;
PMID: 34528173 | DOI: 10.1007/s11481-021-10011-w
Defining the latent human immunodeficiency virus type 1 (HIV-1) burden in the human brain during progressive infection is limited by sample access. Human hematopoietic stem cells (hu-HSCs)-reconstituted humanized mice provide an opportunity for this study. The model mimics, in measure, HIV-1 pathophysiology, transmission, treatment, and elimination in an infected human host. However, to date, brain HIV-1 latency in hu-HSC mice during suppressive antiretroviral therapy (ART) was not studied. To address this need, hu-HSC mice were administered long acting (LA) ART 14 days after HIV-1 infection was established. Animals were maintained under suppressive ART for 3 months, at which time HIV-1 infection was detected at low levels in brain tissue by droplet digital polymerase chain reaction (ddPCR) test on DNA. Notably, adoptive transfer of cells acquired from the hu-HSC mouse brains and placed into naive hu-HSC mice demonstrated viral recovery. These proof-of-concept results demonstrate replication-competent HIV-1 reservoir can be established in hu-HSC mouse brains that persists during long-term ART treatment. Hu-HSC mice-based mouse viral outgrowth assay (hu-MVOA) serves as a sensitive tool to interrogate latent HIV-1 brain reservoirs.
The noncoding genome and hearing loss
Avraham, KB;Khalaily, L;Noy, Y;Kamal, L;Koffler-Brill, T;Taiber, S;
PMID: 34491412 | DOI: 10.1007/s00439-021-02359-z
The age of sequencing has provided unprecedented insights into the human genome. The coding region of the genome comprises nearly 20,000 genes, of which approximately 4000 are associated with human disease. Beyond the protein-coding genome, which accounts for only 3% of the genome, lies a vast pool of regulatory elements in the form of promoters, enhancers, RNA species, and other intricate elements. These features undoubtably influence human health and disease, and as a result, a great deal of effort is currently being invested in deciphering their identity and mechanism. While a paucity of material has caused a lag in identifying these elements in the inner ear, the emergence of technologies for dealing with a minimal number of cells now has the field working overtime to catch up. Studies on microRNAs (miRNAs), long non-coding RNAs (lncRNAs), methylation, histone modifications, and more are ongoing. A number of microRNAs and other noncoding elements are known to be associated with hearing impairment and there is promise that regulatory elements will serve as future tools and targets of therapeutics and diagnostics. This review covers the current state of the field and considers future directions for the noncoding genome and implications for hearing loss.