ABSTRACT
Synaptic function in neurons is modulated by local translation of mRNAs that are transported to distal portions of axons and dendrites. The metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is broadly expressed across cell types, almost exclusively as a nuclear long noncoding RNA. We found that in differentiating neurons, a portion of Malat1 RNA redistributes to the cytoplasm. Depletion of Malat1 using antisense oligonucleotides (ASOs) stimulates the expression of particular pre- and postsynaptic proteins, implicating Malat1 in their regulation. Neuronal Malat1 is localized in puncta of both axons and dendrites that costain with Staufen1 protein, similar to neuronal RNA granules formed by locally translated mRNAs. Ribosome profiling of cultured mouse cortical neurons identified ribosome footprints within a 5' region of Malat1 containing short open reading frames. The upstream-most reading frame (M1) of the Malat1 locus was linked to the GFP-coding sequence in mouse embryonic stem cells. When these gene-edited cells were differentiated into glutamatergic neurons, the M1-GFP fusion protein was expressed. Antibody staining for the M1 peptide confirmed its presence in wild-type neurons and showed that M1 expression was enhanced by synaptic stimulation with KCl. Our results indicate that Malat1 serves as a cytoplasmic coding RNA in the brain that is both modulated by and modulates synaptic function.
Subject(s)
Cytoplasm , Neurons , RNA, Long Noncoding , RNA, Messenger , Animals , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Mice , Neurons/metabolism , Cytoplasm/metabolism , RNA, Messenger/metabolism , RNA, Messenger/genetics , RNA-Binding Proteins/metabolism , RNA-Binding Proteins/genetics , Cells, Cultured , Cell Differentiation , Peptides/metabolism , Peptides/geneticsABSTRACT
Synaptic function is modulated by local translation of mRNAs that are transported to distal portions of axons and dendrites. The Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is broadly expressed across cell types, almost exclusively as a nuclear non-coding RNA. We found that in differentiating neurons, a portion of Malat1 RNA redistributes to the cytoplasm. Depletion of Malat1 from neurons stimulated expression of particular pre- and post- synaptic proteins, implicating Malat1 in their regulation. Neuronal Malat1 is localized to both axons and dendrites in puncta that co-stain with Staufen1 protein, similar to neuronal granules formed by locally translated mRNAs. Ribosome profiling of mouse cortical neurons identified ribosome footprints within a region of Malat1 containing short open reading frames. The upstream-most reading frame (M1) of the Malat1 locus was linked to the GFP coding sequence in mouse ES cells. When these gene-edited cells were differentiated into glutamatergic neurons, the M1-GFP fusion protein was expressed. Antibody staining for the M1 peptide confirmed its presence in wildtype neurons, and showed enhancement of M1 expression after synaptic stimulation with KCL. Our results indicate that Malat1 serves as a cytoplasmic coding RNA in the brain that is both modulated by and modulates synaptic function.
ABSTRACT
Meningiomas are the most prevalent primary intracranial tumors. The majority are benign but can undergo dedifferentiation into advanced grades classified by World Health Organization (WHO) into Grades 1 to 3. Meningiomas' tremendous variability in tumor behavior and slow growth rates complicate their diagnosis and treatment. A deeper comprehension of the molecular pathways and cellular microenvironment factors implicated in meningioma survival and pathology is needed. This review summarizes the known genetic and epigenetic aberrations involved in meningiomas, with a focus on neurofibromatosis type 2 (NF2) and non-NF2 mutations. Novel potential biomarkers for meningioma diagnosis and prognosis are also discussed, including epigenetic-, RNA-, metabolomics-, and protein-based markers. Finally, the landscape of available meningioma-specific animal models is overviewed. Use of these animal models can enable planning of adjuvant treatment, potentially assisting in pre-operative and post-operative decision making. Discovery of novel biomarkers will allow, in combination with WHO grading, more precise meningioma grading, including meningioma identification, subtype determination, and prediction of metastasis, recurrence, and response to therapy. Moreover, these biomarkers may be exploited in the development of personalized targeted therapies that can distinguish between the 15 diverse meningioma subtypes.
ABSTRACT
With the emergence of the COVID-19 pandemic and shortage of adequate personal protective equipment (PPE), hospitals implemented inpatient telemedicine measures to ensure operational readiness and a safe working environment for clinicians. The utility and sustainability of inpatient telemedicine initiatives need to be evaluated as the number of COVID-19 inpatients is expected to continue declining. In this viewpoint, we describe the use of a rapidly deployed inpatient telemedicine workflow at a large academic medical center and discuss the potential impact on PPE savings. In early 2020, videoconferencing software was installed on patient bedside iPads at two academic medical center teaching hospitals. An internal website allowed providers to initiate video calls with patients in any patient room with an activated iPad, including both COVID-19 and non-COVID-19 patients. Patients were encouraged to use telemedicine technology to connect with loved ones via native apps or videoconferencing software. We evaluated the use of telemedicine technology on patients' bedside iPads by monitoring traffic to the internal website. Between May 2020 and March 2021, there were a total of 1240 active users of the Video Visits website (mean 112.7, SD 49.0 connection events per month). Of these, 133 (10.7%) connections were made. Patients initiated 63 (47.4%) video calls with family or friends and sent 37 (27.8%) emails with videoconference connection instructions. Providers initiated a total of 33 (24.8%) video calls with the majority of calls initiated in August (n=22, 67%). There was a low level of adoption of inpatient telemedicine capability by providers and patients. With sufficient availability of PPE, inpatient providers did not find a frequent need to use the bedside telemedicine technology, despite a high census of patients with COVID-19. Compared to providers, patients used videoconferencing capabilities more frequently in September and October 2020. We did not find savings of PPE associated with the use of inpatient telemedicine.
Subject(s)
COVID-19/epidemiology , Personal Protective Equipment/economics , Personal Protective Equipment/supply & distribution , Telemedicine/methods , Cross-Sectional Studies , Female , Humans , Inpatients , Male , Pandemics , SARS-CoV-2/isolation & purificationABSTRACT
Dysfunction of the neuronal RNA binding protein RBFOX1 has been linked to epilepsy and autism spectrum disorders. Rbfox1 loss in mice leads to neuronal hyper-excitability and seizures, but the physiological basis for this is unknown. We identify the vSNARE protein Vamp1 as a major Rbfox1 target. Vamp1 is strongly downregulated in Rbfox1 Nes-cKO mice due to loss of 3' UTR binding by RBFOX1. Cytoplasmic Rbfox1 stimulates Vamp1 expression in part by blocking microRNA-9. We find that Vamp1 is specifically expressed in inhibitory neurons, and that both Vamp1 knockdown and Rbfox1 loss lead to decreased inhibitory synaptic transmission and E/I imbalance. Re-expression of Vamp1 selectively within interneurons rescues the electrophysiological changes in the Rbfox1 cKO, indicating that Vamp1 loss is a major contributor to the Rbfox1 Nes-cKO phenotype. The regulation of interneuron-specific Vamp1 by Rbfox1 provides a paradigm for broadly expressed RNA-binding proteins performing specialized functions in defined neuronal subtypes.