scholarly journals MicroRNA-dependent control of neuroplasticity in affective disorders

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helena Caria Martins ◽  
Gerhard Schratt

AbstractAffective disorders are a group of neuropsychiatric disorders characterized by severe mood dysregulations accompanied by sleep, eating, cognitive, and attention disturbances, as well as recurring thoughts of suicide. Clinical studies consistently show that affective disorders are associated with reduced size of brain regions critical for mood and cognition, neuronal atrophy, and synaptic loss in these regions. However, the molecular mechanisms that mediate these changes and thereby increase the susceptibility to develop affective disorders remain poorly understood. MicroRNAs (miRNAs or miRs) are small regulatory RNAs that repress gene expression by binding to the 3ʹUTR of mRNAs. They have the ability to bind to hundreds of target mRNAs and to regulate entire gene networks and cellular pathways implicated in brain function and plasticity, many of them conserved in humans and other animals. In rodents, miRNAs regulate synaptic plasticity by controlling the morphology of dendrites and spines and the expression of neurotransmitter receptors. Furthermore, dysregulated miRNA expression is frequently observed in patients suffering from affective disorders. Together, multiple lines of evidence suggest a link between miRNA dysfunction and affective disorder pathology, providing a rationale to consider miRNAs as therapeutic tools or molecular biomarkers. This review aims to highlight the most recent and functionally relevant studies that contributed to a better understanding of miRNA function in the development and pathogenesis of affective disorders. We focused on in vivo functional studies, which demonstrate that miRNAs control higher brain functions, including mood and cognition, in rodents, and that their dysregulation causes disease-related behaviors.

2019 ◽  
Vol 130 (6) ◽  
pp. 1049-1063 ◽  
Author(s):  
Logan J. Voss ◽  
Paul S. García ◽  
Harald Hentschke ◽  
Matthew I. Banks

Abstract General anesthetics have been used to ablate consciousness during surgery for more than 150 yr. Despite significant advances in our understanding of their molecular-level pharmacologic effects, comparatively little is known about how anesthetics alter brain dynamics to cause unconsciousness. Consequently, while anesthesia practice is now routine and safe, there are many vagaries that remain unexplained. In this paper, the authors review the evidence that cortical network activity is particularly sensitive to general anesthetics, and suggest that disruption to communication in, and/or among, cortical brain regions is a common mechanism of anesthesia that ultimately produces loss of consciousness. The authors review data from acute brain slices and organotypic cultures showing that anesthetics with differing molecular mechanisms of action share in common the ability to impair neurophysiologic communication. While many questions remain, together, ex vivo and in vivo investigations suggest that a unified understanding of both clinical anesthesia and the neural basis of consciousness is attainable.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi50-vi50
Author(s):  
Tiantian Cui ◽  
Erica Hlavin Bell ◽  
Joseph McElroy ◽  
Kevin Liu ◽  
Pooja Manchanda Gulati ◽  
...  

Abstract BACKGROUND Glioblastomas (GBMs) are the most aggressive primary brain tumors, with an average survival time of less than 15 months. miRNAs are emerging as promising and novel biomarkers in GBM. The aims of this study are: 1) to investigate novel miRNAs biomarkers that affect tumorigenesis and therapeutic sensitivity, and 2) to study the underlying molecular mechanisms in GBM. METHODS Nanostring v3 was performed followed by univariable (UVA) and multivariable (MVA) analyses. Functional studies were conducted to define the role of miR-146a in GBM tumorigenesis and therapeutic response and the molecular mechanisms were investigated. RESULTS UVA analyses demonstrated that miR-146a is one of the top miRNAs that correlated with better prognosis in GBM patients (p=9.21E-05), which was independent of MGMT promoter methylation by MVA analyses (p< 0.001). miR-146a expression was significantly downregulated in recurrent GBM tumors compared with the paired primary GBM tumors (p=0.003). Overexpression of miR-146a significantly inhibited tumor cell growth and sensitized patient-derived primary GBM cells to temozolomide (TMZ) treatment in vitro, and showed statistically significant smaller tumor size (p< 0.01) and prolonged survival (p=0.001) in vivo. In addition, miR-146a is downregulated in glioma cancer stem cells, and overexpression of miR-146a significantly affected glioma cancer stem cell self-renewal. We also found that overexpression of miR-146a significantly inhibited the NF-κB, AKT, and ERK pathways. CONCLUSION Our data suggest, for the first time, that miR-146a predicts favorable prognosis for GBM patients and sensitizes primary GBM cells to TMZ treatment in vitro and in vivo through regulating glioma stem cells. Importantly, miR-146a may prove to be a master switch shutting off AKT, NF-κB, as well as other pathways and may overcome redundancies among these pathways leading to resistance. FUNDING: Bohnenn Fund (to PR), R01CA108633, R01CA169368, U10CA180850-01(NCI), Brain Tumor Funders Collaborative Grant, and The Ohio State University CCC (all to AC).


2008 ◽  
Vol 33 (2) ◽  
pp. 292-299 ◽  
Author(s):  
Jeffrey R. Peterson ◽  
David W. Infanger ◽  
Valdir A. Braga ◽  
Yulong Zhang ◽  
Ram V. Sharma ◽  
...  

The ability to monitor transcription factor (TF) activation in the central nervous system (CNS) has the potential to provide novel information regarding the molecular mechanisms underlying a wide range of neurobiological processes. However, traditional biochemical assays limit the mapping of TF activity to select time points. In vivo bioluminescence imaging (BLI) has emerged as an attractive technology for visualizing internal molecular events in the same animal over time. Here, we evaluated the utility of BLI, in combination with virally mediated delivery of reporter constructs to cardiovascular nuclei, for monitoring of TF activity in these discrete brain regions. Following viral gene transfer of NF-κB-driven luciferase reporter to the subfornical organ (SFO), BLI enabled daily measurements of baseline TF activity in the same animal for 1 mo. Importantly, systemic endotoxin, a stimulator of NF-κB activity, induced dramatic and dose-dependent increases in NF-κB-dependent bioluminescence in the SFO up to 30 days after gene transfer. Cotreatment with a dominant-negative IκBα mutant significantly prevented endotoxin-dependent NF-κB activation, confirming the specificity of the bioluminescence signal. NF-κB-dependent luminescence signals were also stable and inducible 1 mo following delivery of luciferase reporter construct to the paraventricular nucleus or rostral ventrolateral medulla. Lastly, using targeted adenoviral delivery of an AP-1 responsive luciferase reporter, we showed similar baseline and endotoxin-induced AP-1 activity in these same brain regions as with NF-κB reporters. These results demonstrate that BLI, in combination with virally mediated gene transfer, is a powerful method for longitudinal monitoring and quantification of TF activity in targeted CNS nuclei in vivo.


2006 ◽  
Vol 175 (1) ◽  
pp. 99-110 ◽  
Author(s):  
Natasha Y. Frank ◽  
Alvin T. Kho ◽  
Tobias Schatton ◽  
George F. Murphy ◽  
Michael J. Molloy ◽  
...  

Skeletal muscle side population (SP) cells are thought to be “stem”-like cells. Despite reports confirming the ability of muscle SP cells to give rise to differentiated progeny in vitro and in vivo, the molecular mechanisms defining their phenotype remain unclear. In this study, gene expression analyses of human fetal skeletal muscle demonstrate that bone morphogenetic protein 4 (BMP4) is highly expressed in SP cells but not in main population (MP) mononuclear muscle-derived cells. Functional studies revealed that BMP4 specifically induces proliferation of BMP receptor 1a–positive MP cells but has no effect on SP cells, which are BMPR1a-negative. In contrast, the BMP4 antagonist Gremlin, specifically up-regulated in MP cells, counteracts the stimulatory effects of BMP4 and inhibits proliferation of BMPR1a-positive muscle cells. In vivo, BMP4-positive cells can be found in the proximity of BMPR1a-positive cells in the interstitial spaces between myofibers. Gremlin is expressed by mature myofibers and interstitial cells, which are separate from BMP4-expressing cells. Together, these studies propose that BMP4 and Gremlin, which are highly expressed by human fetal skeletal muscle SP and MP cells, respectively, are regulators of myogenic progenitor proliferation.


2020 ◽  
Author(s):  
James A. Frank ◽  
Marc-Joseph Antonini ◽  
Po-Han Chiang ◽  
Andres Canales ◽  
David B. Konrad ◽  
...  

ABSTRACTTo reversibly manipulate neural circuits with increased spatial and temporal control, photoswitchable ligands can add an optical switch to a target receptor or signaling cascade. This approach, termed photopharmacology, has been enabling to molecular neuroscience, however, its application to behavioral experiments has been impeded by a lack of integrated hardware capable of delivering both light and compounds to deep brain regions in moving subjects. Here, we devise a hybrid photochemical genetic approach to target neurons using a photoswitchable agonist of capsaicin receptor (TRPV1), red-AzCA-4. Using the thermal drawing process we created multifunctional fibers that can deliver viruses, photoswitchable ligands, and light to deep brain regions in awake, freely moving mice. We implanted our fibers into the ventral tegmental area (VTA), a midbrain hub of the mesolimbic pathway, and used them to deliver a transgene coding for TRPV1. This sensitized excitatory VTA neurons to red-AzCA-4, and allowed us to optically control conditioned place preference using a mammalian ion-channel, thus extending applications of photopharmacology to behavioral experiments. Applied to endogenous receptors, our approach may accelerate studies of molecular mechanisms underlying animal behavior.


2008 ◽  
Vol 99 (5) ◽  
pp. 2703-2707 ◽  
Author(s):  
Michele Migliore ◽  
Claudio Cannia ◽  
Carmen C. Canavier

Midbrain dopaminergic neurons are involved in several critical brain functions controlling goal-directed behaviors, reinforcing/reward processes, and motivation. Their dysfunctions alter dopamine release and contribute to a vast range of neural disorders, from Parkinson's disease to schizophrenia and addictive behaviors. These neurons have thus been a natural target of pharmacological treatments trying to ameliorate the consequences of several neuropathologies. From this point of view, a clear experimental link has been recently established between the increase in the pacemaker frequency of dopaminergic neurons in vitro after acute ethanol application and a particular ionic current ( Ih). The functional consequences in vivo, however, are not clear and they are very difficult to explore experimentally. Here we use a realistic computational model of dopaminergic neurons in vivo to suggest that ethanol, through its effects on Ih, modifies the temporal structure of the spiking activity. The model predicts that the dopamine level may increase much more during bursting than during pacemaking activity, especially in those brain regions with a slow dopamine clearance rate. The results suggest that a selective pharmacological remedy could thus be devised against the rewarding effects of ethanol that are postulated to mediate alcohol abuse and addiction, targeting the specific HCN genes expressed in dopaminergic neurons.


2019 ◽  
Vol 26 (27) ◽  
pp. 5152-5164 ◽  
Author(s):  
Barbara Budzynska ◽  
Caterina Faggio ◽  
Marta Kruk-Slomka ◽  
Dunja Samec ◽  
Seyed Fazel Nabavi ◽  
...  

Flavonoids are major dietary constituents of plant-based food found ubiquitously in plant kingdom where they are usually present in substantial amounts. Rutin is a flavonol-type polyphenol which consists of the flavonol quercetin and the disaccharide rutinose. Rutin has been reported to exert diverse biological effects such as antitumor and antimicrobial mainly associated to its antioxidant and anti-inflammatory activities. Mental, neurological, and behavioural disorders are an important and growing cause of morbidity. Most of these disorders combine a high prevalence, early onset, progressive clinical course, and impairment of critical brain functions making them a major contributor to the global disease burden. In the present work, the biological in vitro and in vivo effects and the potential therapeutic applications of rutin in neurodegenerative processes are reviewed, as well as their bioavailability and pharmacokinetics, which are essential for a better understanding of its biological effectiveness. Moreover, the present review also provides an overview of the molecular mechanisms through which rutin is proposed to exert its neuroprotective effects.


2003 ◽  
Vol 15 (6) ◽  
pp. 354-367 ◽  
Author(s):  
Mario F Juruena ◽  
Anthony J Cleare ◽  
Moisés E Bauer ◽  
Carmine M Pariante

Changes in the hypothalamic–pituitary–adrenocortical (HPA) system are characteristic of depression, and in the majority of these patients these result in HPA axis hyperactivity. This is further supported by the reduced sensitivity to the inhibitory effects of the glucocorticoid, dexamethasone (DEX), on the production of adrenocorticotropic hormone (ACTH) and cortisol, during the DEX suppression test and the DEX-corticotropin-releasing hormone (DEX/CRH) test. Because the effects of glucocorticoids are mediated by intracellular receptors including, most notably, the glucocorticoid receptor (GR), several studies have examined the number and/or function of GRs in depressed patients. These studies have consistently demonstrated that GR function is impaired in major depression, resulting in reduced GR-mediated negative feedback on the HPA axis and increased production and secretion of CRH in various brain regions postulated to be involved in the causality of depression. This article summarizes the literature on GR in depression and on the impact of antidepressants on the GR in clinical and preclinical studies, and supports the concept that impaired GR signaling is a key mechanism in the pathogenesis of depression, in the absence of clear evidence of decreased GR expression. The data also indicate that antidepressants have direct effects on the GR, leading to enhanced GR function and increased GR expression. Hypotheses regarding the mechanism of these receptor changes involve non-steroid compounds that regulate GR function via second messenger pathways, such as cytokines and neurotransmitters. Moreover, we present recent evidence suggesting that membrane steroid transporters such as the multidrug resistance (MDR) p-glycoprotein, which regulate access of glucocorticoids to the brain, could be a fundamental target of antidepressant treatment. Research in this field will lead to new insights into the pathophysiology and treatment of affective disorders.


2021 ◽  
Author(s):  
Aziz Zafar ◽  
Rebeccah Overton ◽  
Ziad Attia ◽  
Ahmet Ay ◽  
Krista Ingram

Abstract Mood disorders, including anxiety, are associated with disruptions in circadian rhythms and are linked to polymorphisms in circadian clock genes. Molecular mechanisms underlying these connections may be direct—via transcriptional activity of clock genes on downstream mood pathways in the brain, or indirect—via clock gene influences on the phase and amplitude of circadian rhythms which, in turn, modulate physiological processes influencing mood. Employing machine learning combined with statistical approaches, we explored clock genotype combinations that predict risk for anxiety symptoms in a deeply phenotyped population. We identified multiple novel circadian genotypes predictive of anxiety, with the PER3B-AG/CRY1-CG genotype being the strongest predictor of anxiety risk in males. Molecular chronotyping, using clock gene expression oscillations, revealed that advanced circadian phase and robust circadian amplitudes are associated with high levels of anxiety symptoms. Further analyses revealed that individuals with advanced phases and pronounced circadian misalignment were at higher risk for severe anxiety symptoms. Our results support both direct and indirect influences of clock gene variants on mood: while sex-specific clock genotype combinations predictive of anxiety symptoms suggest direct effects on mood pathways, the mediation of PER3B effects on anxiety via diurnal preference measures and the association of circadian phase with anxiety symptoms provide evidence for indirect effects of the molecular clockwork on mood. Unraveling the complex molecular mechanisms underlying the links between circadian physiology and mood is essential to identifying the core clock genes to target in future functional studies, thereby advancing the development of non-invasive treatments for anxiety-related disorders.


2019 ◽  
Vol 20 (4) ◽  
pp. 996 ◽  
Author(s):  
Eiji Shigetomi ◽  
Kozo Saito ◽  
Fumikazu Sano ◽  
Schuichi Koizumi

Astrocytes are abundant cells in the brain that regulate multiple aspects of neural tissue homeostasis by providing structural and metabolic support to neurons, maintaining synaptic environments and regulating blood flow. Recent evidence indicates that astrocytes also actively participate in brain functions and play a key role in brain disease by responding to neuronal activities and brain insults. Astrocytes become reactive in response to injury and inflammation, which is typically described as hypertrophy with increased expression of glial fibrillary acidic protein (GFAP). Reactive astrocytes are frequently found in many neurological disorders and are a hallmark of brain disease. Furthermore, reactive astrocytes may drive the initiation and progression of disease processes. Recent improvements in the methods to visualize the activity of reactive astrocytes in situ and in vivo have helped elucidate their functions. Ca2+ signals in reactive astrocytes are closely related to multiple aspects of disease and can be a good indicator of disease severity/state. In this review, we summarize recent findings concerning reactive astrocyte Ca2+ signals. We discuss the molecular mechanisms underlying aberrant Ca2+ signals in reactive astrocytes and the functional significance of aberrant Ca2+ signals in neurological disorders.


Sign in / Sign up

Export Citation Format

Share Document