RESUMO
ABCA7 loss-of-function variants are associated with increased risk of Alzheimer's disease (AD). Using ABCA7 knockout human iPSC models generated with CRISPR/Cas9, we investigated the impacts of ABCA7 deficiency on neuronal metabolism and function. Lipidomics revealed that mitochondria-related phospholipids, such as phosphatidylglycerol and cardiolipin were reduced in the ABCA7-deficient iPSC-derived cortical organoids. Consistently, ABCA7 deficiency-induced alterations of mitochondrial morphology accompanied by reduced ATP synthase activity and exacerbated oxidative damage in the organoids. Furthermore, ABCA7-deficient iPSC-derived neurons showed compromised mitochondrial respiration and excess ROS generation, as well as enlarged mitochondrial morphology compared to the isogenic controls. ABCA7 deficiency also decreased spontaneous synaptic firing and network formation in iPSC-derived neurons, in which the effects were rescued by supplementation with phosphatidylglycerol or NAD+ precursor, nicotinamide mononucleotide. Importantly, effects of ABCA7 deficiency on mitochondria morphology and synapses were recapitulated in synaptosomes isolated from the brain of neuron-specific Abca7 knockout mice. Together, our results provide evidence that ABCA7 loss-of-function contributes to AD risk by modulating mitochondria lipid metabolism.
Assuntos
Transportadores de Cassetes de Ligação de ATP , Células-Tronco Pluripotentes Induzidas , Metabolismo dos Lipídeos , Camundongos Knockout , Mitocôndrias , Neurônios , Mitocôndrias/metabolismo , Neurônios/metabolismo , Humanos , Animais , Metabolismo dos Lipídeos/fisiologia , Camundongos , Células-Tronco Pluripotentes Induzidas/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/genética , Encéfalo/metabolismoRESUMO
PURPOSE: We sought to delineate a multisystem disorder caused by recessive cysteine-rich with epidermal growth factor-like domains 1 (CRELD1) gene variants. METHODS: The impact of CRELD1 variants was characterized through an international collaboration utilizing next-generation DNA sequencing, gene knockdown, and protein overexpression in Xenopus tropicalis, and in vitro analysis of patient immune cells. RESULTS: Biallelic variants in CRELD1 were found in 18 participants from 14 families. Affected individuals displayed an array of phenotypes involving developmental delay, early-onset epilepsy, and hypotonia, with about half demonstrating cardiac arrhythmias and some experiencing recurrent infections. Most harbored a frameshift in trans with a missense allele, with 1 recurrent variant, p.(Cys192Tyr), identified in 10 families. X tropicalis tadpoles with creld1 knockdown displayed developmental defects along with increased susceptibility to induced seizures compared with controls. Additionally, human CRELD1 harboring missense variants from affected individuals had reduced protein function, indicated by a diminished ability to induce craniofacial defects when overexpressed in X tropicalis. Finally, baseline analyses of peripheral blood mononuclear cells showed similar proportions of immune cell subtypes in patients compared with healthy donors. CONCLUSION: This patient cohort, combined with experimental data, provide evidence of a multisystem clinical syndrome mediated by recessive variants in CRELD1.
Assuntos
Transtornos do Neurodesenvolvimento , Reinfecção , Humanos , Leucócitos Mononucleares , Síndrome , Fenótipo , Arritmias Cardíacas/genética , Transtornos do Neurodesenvolvimento/genética , Moléculas de Adesão Celular/genética , Proteínas da Matriz Extracelular/genéticaRESUMO
Major depressive disorder (MDD) is highly prevalent in adolescents and is a major risk factor for suicidality. Recent evidence shows that accelerated cellular senescence/aging is associated with psychiatric illness, including depression, in adults. The present study examined if the relationships of telomere length (TL) and mitochondrial DNA copy number (mtDNAcn), two critical indicators of cellular senescence/aging, are altered in depressed adolescents and whether these alterations are associated with suicidality, early-life adversities, and other co-occuring factors. In genomic DNA isolated from 53 adolescents (ages 16-19, 19 MDD with suicide attempt/suicidal ideation [MDD + SI/SA], 14 MDD without SA/SI [MDD-SI/SA], and 20 healthy controls [HC]), TL and mtDNAcn were measured as the ratio between the number of telomere repeats and that of a single-copy nuclear-hemoglobin [HBG] gene or the amount of mtDNA (NADH dehydrogenase, subunit 1) relative to HBG. Our data show that TL was significantly lower, and mtDNAcn was significantly higher in the total MDD group than HC. TL was significantly lower and mtDNAcn was significantly higher in the MDD + SA/SI group than in the HC, whereas there were no differences in the MDD-SI/SA group. TL was positively correlated with mtDNAcn in both HC and MDD-SA/SI groups; however, TL was negatively correlated with mtDNAcn in MDD + SA/SI. Furthermore, TL was negatively correlated with the severity of both depression and anxiety, while mtDNAcn was positively correlated with the severity of prior emotional abuse. Our study indicates that cellular senescence is more advanced in depressed adolescents with suicidal ideation and that childhood emotional abuse may participate in such a process.
Assuntos
Transtorno Depressivo Maior , Suicídio , Adulto , Humanos , Adolescente , Criança , Ideação Suicida , Transtorno Depressivo Maior/genética , Variações do Número de Cópias de DNA/genética , DNA Mitocondrial/genética , Telômero/genéticaRESUMO
Inclusion body myositis (IBM) is a progressive, debilitating muscle disease commonly encountered in patients over the age of 50. IBM typically presents with asymmetric, painless, progressive weakness and atrophy of deep finger flexors and/or quadriceps muscle. Many patients with IBM develop dysphagia. However, atypical presentations of IBM with isolated dysphagia, asymptomatic hyper-CKemia, foot drop, proximal weakness, axial weakness, and facial diplegia have been reported. Other acquired and some inherited disorders may present similar to IBM, and this list gets more expansive when considering atypical presentations. In general, disease progression of IBM leads to loss of hand function and impaired ambulation, and most IBM patients become wheelchair dependent within 13-15 years of disease onset. Hence, IBM impacts negatively patients' quality of life and reduces longevity compared to the general population. Acknowledging the complete clinical spectrum of IBM presentation and excluding mimics would shorten the time to diagnosis, lead to prompt initiation of supportive management and avoid unproven therapy. Ongoing advanced phase studies in IBM provide hope that a therapy may soon be available. Therefore, an added potential benefit of early diagnosis would be prompt initiation of disease-modifying therapy once available.
Assuntos
Transtornos de Deglutição , Miosite de Corpos de Inclusão , Miosite , Humanos , Miosite de Corpos de Inclusão/diagnóstico , Miosite de Corpos de Inclusão/genética , Miosite de Corpos de Inclusão/terapia , Qualidade de Vida , Debilidade Muscular/etiologiaRESUMO
PURPOSE OF REVIEW: Missense mutations in valosin-containing protein (VCP) can lead to a multisystem proteinopathy 1 (MSP1) with any combination of limb-girdle distribution inclusion body myopathy (IBM) (present in about 90% of cases), Paget's disease of bone, and frontotemporal dementia (IBMPFD). VCP mutations lead to gain of function activity with widespread disarray in cellular function, with enhanced ATPase activity, increased binding with its cofactors, and reduced mitofusin levels. RECENT FINDINGS: This review highlights novel therapeutic approaches in VCP-MSP in in-vitro and in-vivo models. Furthermore, we also discuss therapies targeting mitochondrial dysfunction, autophagy, TDP-43 pathways, and gene therapies in other diseases with similar pathway involvement which can also be applicable in VCP-MSP. SUMMARY: Being a rare disease, it is challenging to perform large-scale randomized control trials (RCTs) in VCP-MSP. However, it is important to recognize potential therapeutic targets, and assess their safety and efficacy in preclinical models, to initiate RCTs for potential therapies in this debilitating disease.
Assuntos
Demência Frontotemporal , Distrofia Muscular do Cíngulo dos Membros , Humanos , Proteína com Valosina/genética , Demência Frontotemporal/genética , Demência Frontotemporal/terapia , Terapia Genética , Distrofia Muscular do Cíngulo dos Membros/genética , Distrofia Muscular do Cíngulo dos Membros/terapiaRESUMO
OBJECTIVES: Dysphagia is a common debilitating clinical feature of IBM. However, the impact of dysphagia in IBM has been historically overlooked. This study aimed to identify, evaluate and summarize the evidence regarding the assessment and management of dysphagia in persons with IBM undergoing treatment. METHODS: A systematic review was conducted using a multiengine search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Eligible studies had to employ an intervention for persons with IBM, report a swallowing outcome and be published in English. Quality assessments of the eligible studies were performed. RESULTS: Of 239 studies found, 19 met the inclusion criteria. One study was rated as 'fair' and the rest as 'poor' quality, particularly due to the lack of published and validated swallowing assessment procedures and outcome measures. Cricopharyngeal (CP) dysfunction (12/19) was the most commonly reported swallowing abnormality. Interventions for disease management included pharmacological agents (10/19), followed by surgical (3/19), behavioral (1/19) and combined approaches (5/19). Interventions with immunosuppressants, botulinum toxin injection, balloon dilation and/or CP myotomy led to mixed and transient benefits. Few studies examining statins or behavioral therapies (primarily focused on respiratory function) showed no effects for dysphagia. CONCLUSION: Various interventions have been reported to temporarily improve dysphagia in persons with IBM. However, these findings are based on limited and overall low-quality evidence. This study cautions against the generalization of these findings and emphasizes the need for further systematic research to improve the diagnosis and management of dysphagia in IBM.
Assuntos
Transtornos de Deglutição , Miosite de Corpos de Inclusão , Humanos , Transtornos de Deglutição/diagnóstico , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/terapia , Miosite de Corpos de Inclusão/complicações , Miosite de Corpos de Inclusão/diagnóstico , Miosite de Corpos de Inclusão/terapia , Músculos Faríngeos/cirurgia , EndoscopiaRESUMO
OBJECTIVES: Inclusion body myositis (IBM) is the most common idiopathic inflammatory myopathy (IIM) above the age of 50 with a distinct clinical phenotype of progressive, painless, asymmetric weakness predominantly involving the long finger flexors and quadriceps. In this study, we compared comorbidities in IBM with other IIMs (i.e., dermatomyositis (DM) and polymyositis (PM)) from the United States National Inpatient Sample Database. METHODS: We identified patients with a primary diagnosis of IBM or IIM from the National Inpatient Sample (NIS) from 2012 to 2018. We then compared the rate of common inpatient comorbidities between the IBM and IIM. RESULTS: There were 18,819 admissions for patients with either IBM or IIM. IBM patients were older (72.9±10.7 years vs. 59.3±18.4 years for IIM, p<0.001), predominantly men (65.0% vs. 31.2% for IIM, p<0.001), and White Caucasians (82.5% vs. 58.4% for IIM, p<0.001). IBM patients had significantly more frequent events of aspiration pneumonia, atrial fibrillation, falls, and sepsis. The rate of PEG tube placement was also significantly higher. When performing multivariable logistic regression, we found that IBM is a risk factor for aspiration pneumonia (OR 3.03), PEG tube placement (OR 2.91), falls (OR 2.05), and sepsis (OR 1.30) but not for significant cardiovascular events. CONCLUSIONS: IBM increases a patient's risk for dysphagia, falls, and infection as compared to other IIM patients. Further population-based studies are warranted to better elucidate the impact of these comorbidities in patients with IBM.
Assuntos
Dermatomiosite , Miosite de Corpos de Inclusão , Miosite , Pneumonia Aspirativa , Polimiosite , Humanos , Dermatomiosite/diagnóstico , Miosite/diagnósticoRESUMO
OBJECTIVES: Sporadic inclusion body myositis (IBM) is a debilitating idiopathic inflammatory myopathy (IIM) which affects hand function, ambulation, and swallowing. There is no approved pharmacological therapy for IBM, and there is a lack of suitable outcome measure to assess the effect of an intervention. The IBM scientific interest group under IMACS reviewed the previously used outcome measures in IBM clinical studies to lay the path for developing a core set of outcome measures in IBM. METHODS: In this systematised review, we have extracted all outcome measures reported in IBM clinical studies to determine what measures were being used and to assess the need for optimising outcome measures in IBM. RESULTS: We found 13 observational studies, 17 open-label clinical trials, and 15 randomised control trials (RCTs) in IBM. Six-minute walk distance, IBM-functional rating scale (IBM-FRS), quantitative muscle testing, manual muscle testing, maximal voluntary isometric contraction testing, and thigh muscle volume measured by MRI were used as primary outcome measures. Twelve different outcome measures of motor function were used in IBM clinical trials. IBM-FRS was the most used measure of functionality. Swallowing function was reported as a secondary outcome measure in only 3 RCTs. CONCLUSIONS: There are inconsistencies in using outcome measures in clinical studies in IBM. The core set measures developed by the IMACS group for other IIMs are not directly applicable to IBM. As a result, there is an unmet need for an IBM-specific core set of measures to facilitate the evaluation of new potential therapeutics for IBM.
Assuntos
Miosite de Corpos de Inclusão , Miosite , Humanos , Músculo Esquelético , Miosite/complicações , Avaliação de Resultados em Cuidados de Saúde , CaminhadaRESUMO
Mood disorders are the most prevalent psychiatric disorders associated with significant disability, morbidity, and mortality. The risk of suicide is associated with severe or mixed depressive episodes in patients with mood disorders. However, the risk of suicide increases with the severity of depressive episodes and is often presented with higher incidences in bipolar disorder (BD) patients than in patients with major depression (MDD). Biomarker study in neuropsychiatric disorders is critical for developing better treatment plans by facilitating more accurate diagnosis. At the same time, biomarker discovery also provides more objectivity to develop state-of-the-art personalized medicine with increased accuracy through clinical interventions. Recently, colinear changes in miRNA expression between brain and systemic circulation have added great interest in examining their potential as molecular markers in mental disorders, including MDD, BD, and suicidality. A present understanding of circulating miRNAs in body fluids implicates their role in managing neuropsychiatric conditions. Most notably, their use as prognostic and diagnostic markers and their potential role in treatment response have significantly advanced our knowledge base. The present review discusses circulatory miRNAs and their underlying possibilities to be used as a screening tool for assessing major psychiatric conditions, including MDD, BD, and suicidal behavior.
Assuntos
Transtorno Depressivo Maior , MicroRNAs , Humanos , Transtornos do Humor , Ideação Suicida , Transtorno Depressivo Maior/tratamento farmacológico , Biomarcadores , MicroRNAs/uso terapêuticoRESUMO
BACKGROUND: Impaired synaptic plasticity has been linked to dynamic gene regulatory network changes. Recently, gene regulation has been introduced with the emerging concept of unique N6-methyladenosine (m6A)-based reversible transcript methylation. In this study, we tested whether m6A RNA methylation may potentially serve as a link between the stressful insults and altered expression of plasticity-related genes. METHODS: Expression of plasticity genes Nr3c1, Creb1, Ntrk2; m6A-modifying enzymes Fto, methyltransferase like (Mettl)-3 and 14; DNA methylation enzymes Dnmt1, Dnmt3a; transcription factor C/ebp-α; and miRNA-124-3p were determined by quantitative polymerase chain reaction (qPCR) in the hippocampus of rats that showed susceptibility to develop stress-induced depression (learned helplessness). M6A methylation of plasticity-related genes was determined following m6A mRNA immunoprecipitation. Chromatin immunoprecipitation was used to examine the endogenous binding of C/EBP-α to the Fto promoter. MiR-124-mediated post-transcriptional inhibition of Fto via C/EBPα was determined using an in vitro model. RESULTS: Hippocampus of learned helplessness rats showed downregulation of Nr3c1, Creb1, and Ntrk2 along with enrichment in their m6A methylation. A downregulation in demethylating enzyme Fto and upregulation in methylating enzyme Mettl3 were also noted. The Fto promoter was hypomethylated due to the lower expression of Dnmt1 and Dnmt3a. At the same time, there was a lower occupancy of transcription factor C/EBPα on the Fto promoter. Conversely, C/ebp-α transcript was downregulated via induced miR-124-3p expression. CONCLUSIONS: Our study mechanistically linked defective C/EBP-α-FTO-axis, epigenetically influenced by induced expression of miR-124-3p, in modifying m6A enrichment in plasticity-related genes. This could potentially be linked with abnormal neuronal plasticity in depression.
Assuntos
Adenosina , MicroRNAs , Ratos , Animais , Adenosina/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Mensageiro/metabolismo , Metilação de DNA , Fatores de Transcrição/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismoRESUMO
We aim to determine the cumulative and comparative risk of cardiovascular events associated with different Immunomodulatory Drugs (iMiDs) and Proteasome Inhibitor (PIs) in Multiple Myeloma (MM) patients through pairwise and network meta-analysis. Electronic searches were conducted using Ovid MEDLINE, EMBASE, CINAHL, Web of Science, and Clinical Trial Registry (Clinical Trials.gov) up to May 2021. Phase 3 randomized clinical trials (RCTs) reporting cardiotoxicity in MM patients (newly diagnoses and/or relapsed) treated with iMiD and/or PI. Studies, where iMiD or PI was used alongside the chemotherapy versus placebo or no additional drugs (control) in the other arm were included. The primary outcome was the presence of cardiotoxicity after follow-up. Pairwise meta-analysis and network meta-analysis were performed using the frequentist's approach to estimate the odds ratio (OR). Twenty RCTs with 10,373 MM patients were included in this analysis. Eleven studies compared iMiDs with control, seven studies compared PIs with control, and two studies compared bortezomib against carfilzomib. CTACE high-grade (≥grade 3) cardiotoxic events were increased with iMiDs compared to their control counterpart (OR 2.05; 95% CI 1.30-3.26). Similar high-grade cardiotoxicity was also noted more frequently with PI use when compared to the control group (OR 1.67; 95% CI 1.17-2.40). Among the PIs, carfilzomib was associated with a maximum risk of cardiotoxicity (OR 2.68; 95% CI 1.63-4.40). There was no evidence of publication bias among studies. iMiDs and PIs, particularly carfilzomib, appear to be associated with increased risk of high-grade cardiovascular events in MM patients.
Assuntos
Mieloma Múltiplo , Inibidores de Proteassoma , Cardiotoxicidade/tratamento farmacológico , Cardiotoxicidade/etiologia , Humanos , Agentes de Imunomodulação , Mieloma Múltiplo/complicações , Mieloma Múltiplo/tratamento farmacológico , Metanálise em Rede , Inibidores de Proteassoma/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
In the current work we show that the profibrotic actions of TGF-ß are mediated, at least in part, through a metabolic maladaptation in glutamine metabolism and how the inhibition of glutaminase 1 (GLS1) reverses pulmonary fibrosis. GLS1 was found to be highly expressed in fibrotic vs normal lung fibroblasts and the expression of profibrotic targets, cell migration, and soft agar colony formation stimulated by TGF-ß required GLS1 activity. Moreover, knockdown of SMAD2 or SMAD3 as well as inhibition of PI3K, mTORC2, and PDGFR abrogated the induction of GLS1 by TGF-ß. We further demonstrated that the NAD-dependent protein deacetylase, SIRT7, and the FOXO4 transcription factor acted as endogenous brakes for GLS1 expression, which are inhibited by TGF-ß. Lastly, administration of the GLS1 inhibitor CB-839 attenuated bleomycin-induced pulmonary fibrosis. Our study points to an exciting and unexplored connection between epigenetic and transcriptional processes that regulate glutamine metabolism and fibrotic development in a TGF-ß-dependent manner.
Assuntos
Fibroblastos/patologia , Regulação da Expressão Gênica , Glutaminase/metabolismo , Fibrose Pulmonar/patologia , Sirtuínas/metabolismo , Fator de Crescimento Transformador beta/toxicidade , Animais , Antibióticos Antineoplásicos/toxicidade , Bleomicina/toxicidade , Movimento Celular , Células Cultivadas , Feminino , Fibroblastos/metabolismo , Glutaminase/genética , Camundongos , Camundongos Endogâmicos C57BL , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/genética , Fibrose Pulmonar/metabolismo , Transdução de Sinais , Sirtuínas/genética , Proteínas Smad/genética , Proteínas Smad/metabolismoRESUMO
INTRODUCTION: Recommendations for receiving the influenza vaccination in patients with autoimmune neuromuscular disorders, such as myasthenia gravis (MG), chronic inflammatory demyelinating polyneuropathy (CIDP), or Guillain-Barré syndrome (GBS), may vary among neurology practitioners. This survey examined the current practices and perceptions of neurologists regarding the influenza vaccination in these patients. METHODS: We performed an Internet-based survey among neurologists across the United States through online forums for neurologists. RESULTS: Across practice settings, 184 neurologists followed 6465 MG, 2313 CIDP, and 1907 GBS patients. Among the respondents, 82.6%, 58.8%, and 42.3% reported that they recommend the influenza vaccine for all patients with MG, CIDP, and GBS, respectively. Respondents practicing for more than 10 y were more conservative in recommending the influenza vaccine for all patients with MG. A history of exacerbation following the influenza vaccine was regarded as the most important factor influencing vaccine recommendation for MG and CIDP. DISCUSSION: Influenza vaccination recommendation practices varied between surveyed neurologists, despite existing guidelines. Clearer professional society recommendations and education are an unmet need based on this apparent knowledge gap.
Assuntos
Doenças Autoimunes/imunologia , Vacinas contra Influenza , Doenças Neuromusculares/imunologia , Padrões de Prática Médica , Vacinação , Pesquisas sobre Atenção à Saúde , HumanosRESUMO
BACKGROUND: Recent studies suggest that microRNAs (miRNAs) can participate in depression pathogenesis by altering a host of genes that are critical in corticolimbic functioning. The present study focuses on examining whether alterations in the miRNA network in the amygdala are associated with susceptibility or resiliency to develop depression-like behavior in rats. METHODS: Amygdala-specific altered miRNA transcriptomics were determined in a rat depression model following next-generation sequencing method. Target prediction analyses (cis- and trans) and qPCR-based assays were performed to decipher the functional role of altered miRNAs. miRNA-specific target interaction was determined using in vitro transfection assay in neuroblastoma cell line. miRNA-specific findings from the rat in vivo model were further replicated in postmortem amygdala of major depressive disorder (MDD) subjects. RESULTS: Changes in miRNome identified 17 significantly upregulated and 8 significantly downregulated miRNAs in amygdala of learned helpless (LH) compared with nonlearned helpless rats. Prediction analysis showed that the majority of the upregulated miRNAs had target genes enriched for the Wnt signaling pathway. Among altered miRNAs, upregulated miR-128-3p was identified as a top hit based on statistical significance and magnitude of change in LH rats. Target validation showed significant downregulation of Wnt signaling genes in amygdala of LH rats. A discernable increase in expression of amygdalar miR-128-3p along with significant downregulation of key target genes from Wnt signaling (WNT5B, DVL, and LEF1) was noted in MDD subjects. Overexpression of miR-128-3p in a cellular model lead to a marked decrease in the expression of Dvl1 and Lef1 genes, confirming them as validated targets of miR-128-3p. Additional evidence suggested that the amygdala-specific diminished expression of transcriptional repressor Snai1 could be potentially linked to induced miR-128-2 expression in LH rats. Furthermore, an amygdala-specific posttranscriptional switching mechanism could be active between miR-128-3p and RNA binding protein Arpp21 to gain control over their target genes such as Lef1. CONCLUSION: Our study suggests that in amygdala a specific set of miRNAs may play an important role in depression susceptibility, which could potentially be mediated through Wnt signaling.
Assuntos
Tonsila do Cerebelo/metabolismo , Transtorno Depressivo/genética , Epigênese Genética/genética , Predisposição Genética para Doença/genética , Desamparo Aprendido , MicroRNAs/metabolismo , Via de Sinalização Wnt/genética , Animais , Comportamento Animal/fisiologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Humanos , Masculino , MicroRNAs/genética , Ratos , Ratos Sprague-DawleyRESUMO
MicroRNAs (miRs) and Hox transcription factors have decisive roles in postnatal bone formation and homeostasis. In silico analysis identified extensive interaction between HOXA cluster mRNA and microRNAs from the miR-23a cluster. However, Hox regulation by the miR-23a cluster during osteoblast differentiation remains undefined. We examined this regulation in preosteoblasts and in a novel miR-23a cluster knockdown mouse model. Overexpression and knockdown of the miR-23a cluster in preosteoblasts decreased and increased, respectively, the expression of the proteins HOXA5, HOXA10, and HOXA11; these proteins' mRNAs exhibited significant binding with the miR-23a cluster miRNAs, and miRNA 3'-UTR reporter assays confirmed repression. Importantly, during periods correlating with development and differentiation of bone cells, we found an inverse pattern of expression between HoxA factors and members of the miR-23a cluster. HOXA5 and HOXA11 bound to bone-specific promoters, physically interacted with transcription factor RUNX2, and regulated bone-specific genes. Depletion of HOXA5 or HOXA11 in preosteoblasts also decreased cellular differentiation. Additionally, stable overexpression of the miR-23a cluster in osteoblasts decreased the recruitment of HOXA5 and HOXA11 to osteoblast gene promoters, significantly inhibiting histone H3 acetylation. Heterozygous miR-23a cluster knockdown female mice (miR-23a ClWT/ZIP) had significantly increased trabecular bone mass when compared with WT mice. Furthermore, miR-23a cluster knockdown in calvarial osteoblasts of these mice increased the recruitment of HOXA5 and HOXA11, with a substantial enrichment of promoter histone H3 acetylation. Taken together, these findings demonstrate that the miR-23a cluster is required for maintaining stage-specific HoxA factor expression during osteogenesis.
Assuntos
Regiões 3' não Traduzidas , Diferenciação Celular , Proteínas de Homeodomínio/metabolismo , MicroRNAs/metabolismo , Família Multigênica , Osteoblastos/metabolismo , Fosfoproteínas/metabolismo , Acetilação , Animais , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Células HEK293 , Histonas/genética , Histonas/metabolismo , Proteínas de Homeodomínio/genética , Humanos , Camundongos , MicroRNAs/genética , Osteoblastos/citologia , Osteogênese , Fosfoproteínas/genética , Fatores de TranscriçãoRESUMO
Background: Recent emergence of long noncoding RNAs in regulating gene expression and thereby modulating physiological functions in brain has manifested their possible role in psychiatric disorders. In this study, the roles of long noncoding RNAs in susceptibility and resiliency to develop stress-induced depression and their response to antidepressant treatment were examined. Methods: Microarray-based transcriptome-wide changes in long noncoding RNAs were determined in hippocampus of male Holtzman rats who showed susceptibility (learned helplessness) or resiliency (nonlearned helplessness) to develop depression. Changes in long noncoding RNA expression were also ascertained after subchronic administration of fluoxetine to learned helplessness rats. Bioinformatic and target prediction analyses (cis- and trans-acting) and qPCR-based assays were performed to decipher the functional role of altered long noncoding RNAs. Results: Group-wise comparison showed an overrepresented class of long noncoding RNAs that were uniquely associated with nonlearned helplessness or learned helplessness behavior. Chromosomal mapping within the 5-kbp flank region of the top 20 dysregulated long noncoding RNAs in the learned helplessness group showed several target genes that were regulated through cis- or trans-actions, including Zbtb20 and Zfp385b from zinc finger binding protein family. Genomic context of differentially expressed long noncoding RNAs showed an overall blunted response in the learned helplessness group regardless of the long noncoding RNA classes analyzed. Gene ontology exhibited the functional clustering for anatomical structure development, cellular architecture modulation, protein metabolism, and cellular communications. Fluoxetine treatment reversed learned helplessness-induced changes in many long noncoding RNAs and target genes. Conclusions: The involvement of specific classes of long noncoding RNAs with distinctive roles in modulating target gene expression could confer the role of long noncoding RNAs in resiliency or susceptibility to develop depression with a reciprocal response to antidepressant treatment.
Assuntos
Antidepressivos de Segunda Geração/farmacologia , Comportamento Animal , Depressão , Fluoxetina/farmacologia , Expressão Gênica , Predisposição Genética para Doença/genética , Desamparo Aprendido , Hipocampo , RNA Longo não Codificante , Resiliência Psicológica , Transcriptoma , Animais , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Depressão/tratamento farmacológico , Depressão/genética , Depressão/fisiopatologia , Modelos Animais de Doenças , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , RNA Longo não Codificante/efeitos dos fármacos , RNA Longo não Codificante/genética , Ratos , Ratos Sprague-Dawley , Transcriptoma/efeitos dos fármacos , Transcriptoma/genéticaRESUMO
BACKGROUND: The main reason for morbidity after aneurysmal subarachnoid hemorrhage (aSAH) is delayed cerebral ischemia (DCI). The mainstay of medical therapy for treating DCI is induced hypertension with vasopressors to restore cerebral perfusion. Both phenylephrine (PE) and norepinephrine (NE) are commonly used for induced hypertension, but the impact of the initial choice of vasopressor on the efficacy, adverse effects, or outcome after hemodynamic therapy for DCI is unknown. METHODS: Sixty-three patients with aSAH between January 2012 and October 2014, who developed DCI (defined as new focal deficit or decline in Glasgow Coma Score) and in which PE (n = 45) or NE (n = 18) treatment was initiated were evaluated in this retrospective study. Baseline characteristics, adverse effects, the need to change or add vasopressors, the response to therapy, the need for endovascular therapy, new infarct development, discharge disposition, and 3 months modified Rankin score were all compared between pressor groups. RESULTS: Baseline characteristics (e.g., Hunt Hess and Fisher grades) were similar. There were no differences in the overall rate of complications including arrhythmia, pulmonary edema, or kidney injury. However, those initiated on PE were more likely to be changed to an alternate vasopressor (64 vs. 33%, p = 0.016), mostly for bradycardia or failure to reach therapeutic targets. Patients initially treated with PE were less likely to respond neurologically (71 vs. 94%, p = 0.01) or to be discharged to home or acute rehabilitation facilities (73 vs. 94%, p = 0.02) and were more likely to have a delayed infarct on imaging (62 vs. 33%, p = 0.04). CONCLUSIONS: Our study suggests that patients with DCI after aSAH initiated on PE are more likely to require treatment change to another vasopressor and are at greater risk for poor clinical outcomes compared to patients started on NE. Larger comparative studies are warranted.