Induction of miR-155 after Brain Injury Promotes Type 1 Interferon and has a Neuroprotective Effect

Pegylated polymeric micelles of boswellic acid-selenium mitigates repetitive mild traumatic brain injury: Regulation of miR-155 and miR-146a/BDNF/ Klotho/Foxo3a cue

This study aims to explore the protective machinery of pegylated polymeric micelles of boswellic acid-selenium (PMBS) against secondary neuronal damage triggered by mild repetitive traumatic brain injury (RTBI). After PMBS characterization in terms of particle size, size distribution, zeta potential, and transmission electronic microscopy, the selected formula was used to investigate its potency against experimental RTBI. Five groups of rats were used; group 1 (control) and the other four groups were subjected to RTBI. Groups 2 was RTBI positive control, while 3, 4, and 5 received boswellic acid (BSA), selenium (SEL), and PMBS, respectively. The open-field behavioral test was used for behavioral assessment. Subsequently, brain tissues were utilized for hematoxylin and eosin staining, Nissl staining, Western blotting, and ELISA in addition to evaluating microRNA expression (miR-155 and miR-146a). The behavioral changes, oxidative stress, and neuroinflammation triggered by RTBI were all improved by PMBS. Moreover, PMBS mitigated excessive glutamate-induced excitotoxicity and the dysregulation in miR-155 and miR-146a expression. Besides, connexin43 (Cx43) expression as well as klotho and brain-derived neurotrophic factor (BDNF) were upregulated with diminished neuronal cell death and apoptosis because of reduced Forkhead Box class O3a(Foxo3a) expression in the PMBS-treated group. The current study has provided evidence of the benefits produced by incorporating BSA and SEL in PEGylated polymeric micelles formula. PMBS is a promising therapy for RTBI. Its beneficial effects are attributed to the manipulation of many pathways, including the regulation of miR-155 and miR-146a expression, as well as the BDNF /Klotho/Foxo3a signaling pathway.

Extracellular vesicles as nanotheranostic platforms for targeted neurological disorder interventions

Central Nervous System (CNS) disorders represent a profound public health challenge that affects millions of people around the world. Diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and traumatic brain injury (TBI) exemplify the complexities and diversities that complicate their early detection and the development of effective treatments. Amid these challenges, the emergence of nanotechnology and extracellular vesicles (EVs) signals a new dawn for treating and diagnosing CNS ailments. EVs are cellularly derived lipid bilayer nanosized particles that are pivotal in intercellular communication within the CNS and have the potential to revolutionize targeted therapeutic delivery and the identification of novel biomarkers. Integrating EVs with nanotechnology amplifies their diagnostic and therapeutic capabilities, opening new avenues for managing CNS diseases. This review focuses on examining the fascinating interplay between EVs and nanotechnology in CNS theranostics. Through highlighting the remarkable advancements and unique methodologies, we aim to offer valuable perspectives on how these approaches can bring about a revolutionary change in disease management. The objective is to harness the distinctive attributes of EVs and nanotechnology to forge personalized, efficient interventions for CNS disorders, thereby providing a beacon of hope for affected individuals. In short, the confluence of EVs and nanotechnology heralds a promising frontier for targeted and impactful treatments against CNS diseases, which continue to pose significant public health challenges. By focusing on personalized and powerful diagnostic and therapeutic methods, we might improve the quality of patients.

Pathogenesis of miR-155 on nonmodifiable and modifiable risk factors in Alzheimer's disease

Alzheimer's disease (AD) is a common age-related neurodegenerative disease in the central nervous system and is the primary cause of dementia. It is clinically characterized by the memory impairment, aphasia, apraxia, agnosia, visuospatial and executive dysfunction, behavioral changes, and so on. Incidence of this disease was bound up with age, genetic factors, cardiovascular and cerebrovascular dysfunction, and other basic diseases, but the exact etiology has not been clarified. MicroRNAs (miRNAs) are small endogenous non-coding RNAs that were involved in the regulation of post-transcriptional gene expression. miRNAs have been extensively studied as noninvasive potential biomarkers for disease due to their relative stability in bodily fluids. In addition, they play a significant role in the physiological and pathological processes of various neurological disorders, including stroke, AD, and Parkinson's disease. MiR-155, as an important pro-inflammatory mediator of neuroinflammation, was reported to participate in the progression of β-amyloid peptide and tau via regulating immunity and inflammation. In this review, we put emphasis on the effects of miR-155 on AD and explore the underlying biological mechanisms which could provide a novel approach for diagnosis and treatment of AD.

Interaction Between Non-Coding RNAs and Interferons: With an Especial Focus on Type I Interferons

Interferons (IFNs) are a group of cellular proteins with critical roles in the regulation of immune responses in the course of microbial infections. Moreover, expressions of IFNs are dysregulated in autoimmune disorders. IFNs are also a part of immune responses in malignant conditions. The expression of these proteins and activities of related signaling can be influenced by a number of non-coding RNAs. IFN regulatory factors (IRFs) are the most investigated molecules in the field of effects of non-coding RNAs on IFN signaling. These interactions have been best assessed in the context of cancer, revealing the importance of immune function in the pathoetiology of cancer. In addition, IFN-related non-coding RNAs may contribute to the pathogenesis of neuropsychiatric conditions, systemic sclerosis, Newcastle disease, Sjögren’s syndrome, traumatic brain injury, lupus nephritis, systemic lupus erythematosus, diabetes mellitus, and myocardial ischemia/reperfusion injury. In the current review, we describe the role of microRNAs and long non-coding RNAs in the regulation of IFN signaling.

Neuronal Redevelopment and the Regeneration of Neuromodulatory Axons in the Adult Mammalian Central Nervous System

One reason that many central nervous system injuries, including those arising from traumatic brain injury, spinal cord injury, and stroke, have limited recovery of function is that neurons within the adult mammalian CNS lack the ability to regenerate their axons following trauma. This stands in contrast to neurons of the adult mammalian peripheral nervous system (PNS). New evidence, provided by single-cell expression profiling, suggests that, following injury, both mammalian central and peripheral neurons can revert to an embryonic-like growth state which is permissive for axon regeneration. This “redevelopment” strategy could both facilitate a damage response necessary to isolate and repair the acute damage from injury and provide the intracellular machinery necessary for axon regrowth. Interestingly, serotonin neurons of the rostral group of raphe nuclei, which project their axons into the forebrain, display a robust ability to regenerate their axons unaided, counter to the widely held view that CNS axons cannot regenerate without experimental intervention after injury. Furthermore, initial evidence suggests that norepinephrine neurons within the locus coeruleus possess similar regenerative abilities. Several morphological characteristics of serotonin axon regeneration in adult mammals, observable using longitudinal in vivo imaging, are distinct from the known characteristics of unaided peripheral nerve regeneration, or of the regeneration seen in the spinal cord and optic nerve that occurs with experimental intervention. These results suggest that there is an alternative CNS program for axon regeneration that likely differs from that displayed by the PNS.

MicroRNA miR-155 Activity in Mouse Choline Acetyltransferase-Positive Neurons Is Critical for the Rate of Early and Late Paraplegia After Transient Aortic Cross-Clamping

Aortic aneurism open repair surgery can cause spinal cord (SC) injury with 5–15% of patients developing paraparesis or paraplegia. Using a mouse model of transient aortic cross-clamping (ACC), we have previously found that the expression of proinflammatory microRNA miR-155 increases in motoneurons (MNs) and endothelial cells (ECs) of ischemic SCs, and that global miR-155 deletion decreases the percentage of paraplegia by 37.4% at 48-h post-ACC. Here, we investigated the cell-specific contribution of miR-155 in choline acetyltransferase-positive (ChAT+) neurons (that include all MNs of the SC) and ECs to SC injury after ACC. Mice lacking miR-155 in ChAT+ neurons (MN-miR-155-KO mice) developed 24.6% less paraplegia than control mice at 48-h post-ACC. In contrast, mice lacking miR-155 in ECs (ECs-miR-155-KO mice) experienced the same percentage of paraplegia as control mice, despite presenting smaller central cord edema. Unexpectedly, mice overexpressing miR-155 in ChAT+ neurons were less likely than control mice to develop early paraplegia during the first day post-ACC, however they reached the same percentage of paraplegia at 48-h. In addition, all mice overexpressing miR-155 in ECs (ECs-miR-155-KI mice) were paraplegic at 48-h post-ACC. Altogether, our results suggest that miR-155 activity in ChAT+ neurons protects the SC against ischemic injury during the first day post-ACC before becoming deleterious during the second day, which indicates that early and late paraplegias arise from different molecular malfunctions. These results point to the need to develop specific protective therapeutics aimed at inhibiting both the early and late deleterious events after open repair surgery of aortic aneurisms.

MiR-155: An Important Regulator of Neuroinflammation

MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression at the post-transcriptional level and that play an important role in many cellular processes, including modulation of inflammation. MiRNAs are present in high concentrations in the central nervous system (CNS) and are spatially and temporally expressed in a specific way. Therefore, an imbalance in the expression pattern of these small molecules can be involved in the development of neurological diseases. Generally, CNS responds to damage or disease through the activation of an inflammatory response, but many neurological disorders are characterized by uncontrolled neuroinflammation. Many studies support the involvement of miRNAs in the activation or inhibition of inflammatory signaling and in the promotion of uncontrolled neuroinflammation with pathological consequences. MiR-155 is a pro-inflammatory mediator of the CNS and plays an important regulatory role. The purpose of this review is to summarize how miR-155 is regulated and the pathological consequences of its deregulation during neuroinflammatory disorders, including multiple sclerosis, Alzheimer's disease and other neuroinflammatory disorders. Modulation of miRNAs' expression could be used as a therapeutic strategy in the treatment of pathological neuroinflammation.

Out-of-Field Hippocampus from Partial-Body Irradiated Mice Displays Changes in Multi-Omics Profile and Defects in Neurogenesis

The brain undergoes ionizing radiation exposure in many clinical situations, particularly during radiotherapy for brain tumors. The critical role of the hippocampus in the pathogenesis of radiation-induced neurocognitive dysfunction is well recognized. The goal of this study is to test the potential contribution of non-targeted effects in the detrimental response of the hippocampus to irradiation and to elucidate the mechanisms involved. C57Bl/6 mice were whole body (WBI) or partial body (PBI) irradiated with 0.1 or 2.0 Gy of X-rays or sham irradiated. PBI consisted of the exposure of the lower third of the mouse body, whilst the upper two thirds were shielded. Hippocampi were collected 15 days or 6 months post-irradiation and a multi-omics approach was adopted to assess the molecular changes in non-coding RNAs, proteins and metabolic levels, as well as histological changes in the rate of hippocampal neurogenesis. Notably, at 2.0 Gy the pattern of early molecular and histopathological changes induced in the hippocampus at 15 days following PBI were similar in quality and quantity to the effects induced by WBI, thus providing a proof of principle of the existence of out-of-target radiation response in the hippocampus of conventional mice. We detected major alterations in DAG/IP3 and TGF-β signaling pathways as well as in the expression of proteins involved in the regulation of long-term neuronal synaptic plasticity and synapse organization, coupled with defects in neural stem cells self-renewal in the hippocampal dentate gyrus. However, compared to the persistence of the WBI effects, most of the PBI effects were only transient and tended to decrease at 6 months post-irradiation, indicating important mechanistic difference. On the contrary, at low dose we identified a progressive accumulation of molecular defects that tended to manifest at later post-irradiation times. These data, indicating that both targeted and non-targeted radiation effects might contribute to the pathogenesis of hippocampal radiation-damage, have general implications for human health.

Long non-coding RNA LNC_000641 regulates pseudorabies virus replication

Long non-coding RNAs (lncRNAs) are a new arm of gene regulatory mechanism as discovered by sequencing techniques and follow-up functional studies. The lncRNAs regulation of pseudorabies virus (PRV) infection has rarely been reported so far. Using RNA sequencing analysis, 225 lncRNAs with significant altered expressions in 3D4/21 cells infected with PRV (ZJ01) were identified. Five lncRNAs upregulated in PRV-infected cells were verified in cells infected with different PRV strains by qRT-PCR. By down- and up-regulation of lnc641, the accelerating effect of lnc641 on PRV replication was confirmed. Furthermore, we found that lnc641 regulated PRV replication by inhibiting the JAK-STAT1 pathway. This study suggests that lnc641 could be a new host factor target for developing antiviral therapies against PRV infection.

Seizures and memory impairment induced by patient-derived anti-N-methyl-D-aspartate receptor antibodies in mice are attenuated by anakinra, an interleukin-1 receptor antagonist

OBJECTIVE

Neuroinflammation associated with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis may facilitate seizures. We previously showed that intraventricular administration of cerebrospinal fluid from patients with anti-NMDAR encephalitis to mice precipitates seizures, thereby confirming that antibodies are directly pathogenic. To determine whether interleukin (IL)-1-mediated inflammation exacerbates autoimmune seizures, we asked whether blocking the effects of IL-1 by anakinra, a selective IL-1 receptor antagonist, blunts antibody-induced seizures.

METHODS

We infused C57BL/6 mice intraventricularly with purified serum IgG from patients with anti-NMDAR encephalitis or monoclonal anti-NMDAR IgG; subdural electroencephalogram was continuously recorded. After a 6-day interval, mice received anakinra (25 mg/kg sc, twice daily) or vehicle for 5 days. Following a 4-day washout period, we performed behavioral tests to assess motor function, anxiety, and memory, followed by hippocampus tissue analysis to assess astrocytic (glial fibrillary acidic protein [GFAP]) and microglial (ionized calcium-binding adapter molecule [Iba]-1) activation.

RESULTS

Of 31 mice infused with purified patient NMDAR-IgG (n = 17) or monoclonal NMDAR-IgG (n = 14), 81% developed seizures. Median baseline daily seizure count during exposure to antibodies was 3.9; most seizures were electrographic. Median duration of seizures during the baseline was 82.5 s. Anakinra administration attenuated daily seizure frequency by 60% (p = .02). Anakinra reduced seizure duration; however, the effect was delayed and became apparent only after the cessation of treatment (p = .04). Anakinra improved novel object recognition in mice with antibody-induced seizures (p = .03) but did not alter other behaviors. Anakinra reduced the expression of GFAP and Iba-1 in the hippocampus of mice with seizures, indicating decreased astrocytic and microglial activation.

SIGNIFICANCE

Our evidence supports a role for IL-1 in the pathogenesis of seizures in anti-NMDAR encephalitis. These data are consistent with therapeutic effects of anakinra in other severe autoimmune and inflammatory seizure syndromes. Targeting inflammation via blocking IL-1 receptor-mediated signaling may be promising for developing novel treatments for refractory autoimmune seizures.

Inhibition of microRNA-155 Protects Retinal Function Through Attenuation of Inflammation in Retinal Degeneration

Although extensively investigated in inflammatory conditions, the role of pro-inflammatory microRNAs (miRNAs), miR-155 and miR-146a, has not been well-studied in retinal degenerative diseases. We therefore aimed to explore the role and regulation of these miRNA in the degenerating retina, with a focus on miR-155. C57BL/6J mice were subjected to photo-oxidative damage for up to 5 days to induce focal retinal degeneration. MiR-155 expression was quantified by qRT-PCR in whole retina, serum, and small-medium extracellular vesicles (s-mEVs), and a PrimeFlow™ assay was used to identify localisation of miR-155 in retinal cells. Constitutive miR-155 knockout (KO) mice and miR-155 and miR-146a inhibitors were utilised to determine the role of these miRNA in the degenerating retina. Electroretinography was employed as a measure of retinal function, while histological quantification of TUNEL+ and IBA1+ positive cells was used to quantify photoreceptor cell death and infiltrating immune cells, respectively. Upregulation of miR-155 was detected in retinal tissue, serum and s-mEVs in response to photo-oxidative damage, localising to the nucleus of a subset of retinal ganglion cells and glial cells and in the cytoplasm of photoreceptors. Inhibition of miR-155 showed increased function from negative controls and a less pathological pattern of IBA1+ cell localisation and morphology at 5 days photo-oxidative damage. While neither dim-reared nor damaged miR-155 KO animals showed retinal histological difference from controls, following photo-oxidative damage, miR-155 KO mice showed increased a-wave relative to controls. We therefore consider miR-155 to be associated with the inflammatory response of the retina in response to photoreceptor-specific degeneration.

What Is in the Field for Genetics and Epigenetics of Diabetic Neuropathy: The Role of MicroRNAs

Despite the high prevalence of diabetic neuropathy, its early start, and its impact on quality of life and mortality, unresolved clinical issues persist in the field regarding its screening implementation, the understanding of its mechanisms, and the search for valid biomarkers, as well as disease-modifying treatment. Genetics may address these needs by providing genetic biomarkers of susceptibility, giving insights into pathogenesis, and shedding light on how to select possible responders to treatment. After a brief summary of recent studies on the genetics of diabetic neuropathy, the current review focused mainly on microRNAs (miRNAs), including the authors' results in this field. It summarized the findings of animal and human studies that associate miRNAs with diabetic neuropathy and explored the possible pathogenetic meanings of these associations, in particular regarding miR-128a, miR-155a, and miR-499a, as well as their application for diabetic neuropathy screening. Moreover, from a genetic perspective, it examined new findings of polymorphisms of miRNA genes in diabetic neuropathy. It considered in more depth the pathogenetic implications for diabetic neuropathy of the polymorphism of MIR499A and the related changes in the downstream action of miR-499a, showing how epigenetic and genetic studies may provide insight into pathogenetic mechanisms like mitochondrial dysfunction. Finally, the concept and the data of genotype-phenotype association for polymorphism of miRNA genes were described. In conclusion, although at a very preliminary stage, the findings linking the genetics and epigenetics of miRNAs might contribute to the identification of exploratory risk biomarkers, a comprehensive definition of susceptibility to specific pathogenetic mechanisms, and the development of mechanism-based treatment of diabetic neuropathy, thus addressing the goals of genetic studies.

Temporal changes in inflammatory mitochondria-enriched microRNAs following traumatic brain injury and effects of miR-146a nanoparticle delivery

MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate post-transcriptional gene expression and contribute to all aspects of cellular function. We previously reported that the activities of several mitochondria-enriched miRNAs regulating inflammation (i.e., miR-142-3p, miR-142-5p, and miR-146a) are altered in the hippocampus at 3-12 hours following a severe traumatic brain injury. In the present study, we investigated the temporal expression profile of these inflammatory miRNAs in mitochondria and cytosol fractions at more chronic post-injury times following severe controlled cortical impact injury in rats. In addition, several inflammatory genes were analyzed in the cytosol fractions. The analysis showed that while elevated levels were observed in cytoplasm, the mitochondria-enriched miRNAs, miR-142-3p and miR-142-5p continued to be significantly reduced in mitochondria from injured hippocampi for at least 3 days and returned to near normal levels at 7 days post-injury. Although not statistically significant, miR-146a also remained at reduced levels for up to 3 days following controlled cortical impact injury, and recovered by 7 days. In contrast, miRNAs that are not enriched in mitochondria, including miR-124a, miR-150, miR-19b, miR-155, and miR-223 were either increased or demonstrated no change in their levels in mitochondrial fractions for 7 days. The one exception was that miR-223 levels were reduced in mitochondria at 1 day following injury. No major alterations were observed in sham operated animals. This temporal pattern was unique to mitochondria-enriched miRNAs and correlated with injury-induced changes in mitochondrial bioenergetics as well as expression levels of several inflammatory markers. These observations suggested a potential compartmental re-distribution of the mitochondria-enriched inflammatory miRNAs and may reflect an intracellular mechanism by which specific miRNAs regulate injury-induced inflammatory signaling. To test this, we utilized a novel peptide-based nanoparticle strategy for in vitro and in vivo delivery of a miR-146a mimic as a potential therapeutic strategy for targeting nuclear factor-kappaB inflammatory modulators in the injured brain. Nanoparticle delivery of miR-146a to BV-2 or SH-SY5Y cells significantly reduced expression of TNF receptor-associated factor 6 (TRAF6) and interleukin-1 receptor-associated kinase 1 (IRAK1), two important modulators of the nuclear factor-kappaB (NF-κB) pro-inflammatory pathway. Moreover, injections of miR-146a containing nanoparticles into the brain immediately following controlled cortical impact injury significantly reduced hippocampal TNF receptor-associated factor 6 and interleukin-1 receptor-associated kinase 1 levels. Taken together, our studies demonstrate the subcellular alteration of inflammatory miRNAs after traumatic brain injury and establish proof of principle that nanoparticle delivery of miR-146a has therapeutic potential for modulating pro-inflammatory effectors in the injured brain. All of the studies performed were approved by the University of Kentucky Institutional Animal Care and Usage Committee (IACUC protocol # 2014-1300) on August 17, 2017.

miRNAs as Potential Biomarkers for Traumatic Brain Injury: Pathway From Diagnosis to Neurorehabilitation

BACKGROUND

Biomarkers that can advance precision neurorehabilitation of the traumatic brain injury (TBI) are needed. MicroRNAs (miRNAs) have biological properties that could make them well suited for playing key roles in differential diagnoses and prognoses and informing likelihood of responsiveness to specific treatments.

OBJECTIVE

To review the evidence of miRNA alterations after TBI and evaluate the state of science relative to potential neurorehabilitation applications of TBI-specific miRNAs.

METHODS

This scoping review includes 57 animal and human studies evaluating miRNAs after TBI. PubMed, Scopus, and Google Scholar search engines were used.

RESULTS

Gold standard analytic steps for miRNA biomarker assessment are presented. Published studies evaluating the evidence for miRNAs as potential biomarkers for TBI diagnosis, severity, natural recovery, and treatment-induced outcomes were reviewed including statistical evaluation. Growing evidence for specific miRNAs, including miR21, as TBI biomarkers is presented.

CONCLUSIONS

There is evidence of differential miRNA expression in TBI in both human and animal models; however, gaps need to be filled in terms of replication using rigorous, standardized methods to isolate a consistent set of miRNA changes. Longitudinal studies in TBI are needed to understand how miRNAs could be implemented as biomarkers in clinical practice.

Increased expression of miR142 and miR155 in glial and immune cells after traumatic brain injury may contribute to neuroinflammation via astrocyte activation

Traumatic brain injury (TBI) is associated with the pathological activation of immune-competent cells in the brain, such as astrocytes, microglia and infiltrating immune blood cells, resulting in chronic inflammation and gliosis. This may contribute to the secondary injury after TBI, thus understanding of these processes is crucial for the development of effective treatments of post-traumatic pathologies. MicroRNAs (miRNAs, miRs) are small noncoding RNAs, functioning as posttranscriptional regulators of gene expression. The increased expression of inflammation-associated microRNAs miR155 and miR142 has been reported after TBI in rats. However, expression of these miRNAs in the human brain post-TBI is not studied and their functions are not well understood. Moreover, circulating miR155 and miR142 are candidate biomarkers. Therefore, we characterized miR142 and miR155 expression in the perilesional cortex and plasma of rats that underwent lateral fluid-percussion injury, a model for TBI and in the human perilesional cortex post-TBI. We demonstrated higher miR155 and miR142 expression in the perilesional cortex of rats 2 weeks post-TBI. In plasma, miR155 was associated with proteins and miR142 with extracellular vesicles, however their expression did not change. In the human perilesional cortex miR155 was most prominently expressed by activated astrocytes, whereas miR142 was expressed predominantly by microglia, macrophages and lymphocytes. Pro-inflammatory medium from macrophage-like cells stimulated miR155 expression in astrocytes and overexpression of miR142 in these cells further potentiated a pro-inflammatory state of activated astrocytes. We conclude that miR155 and miR142 promote brain inflammation via astrocyte activation and may be involved in the secondary brain injury after TBI.

Astrocyte regional diversity in ALS includes distinct aberrant phenotypes with common and causal pathological processes

Astrocytes are major contributors of motor neuron (MN) degeneration in amyotrophic lateral sclerosis (ALS). We investigated whether regional and cell maturation differences influence ALS astrocyte malfunction. Spinal and cortical astrocytes from SOD1G93A (mSOD1) 7-day-old mice were cultured for 5 and 13 days in vitro (DIV). Astrocyte aberrancies predominated in 13DIV cells with region specificity. 13DIV cortical mSOD1 astrocytes showed early morphological changes and a predominant reactive and inflammatory phenotype, while repressed proteins and genes were found in spinal cells. Inflammatory-associated miRNAs, e.g. miR-155/miR-21/miR-146a, were downregulated in the first and upregulated in the later ones. Interestingly, depleted miR-155/miR-21/miR-146a in small extracellular vesicles (sEVs/exosomes) was a common pathological feature. Cortical mSOD1 astrocytes induced late apoptosis and kinesin-1 downregulation in mSOD1 NSC-34 MNs, whereas spinal cells upregulated dynein, while decreased nNOS and synaptic-related genes. Both regional-distinct mSOD1 astrocytes enhanced iNOS gene expression in mSOD1 MNs. We provide information on the potential contribution of astrocytes to ALS bulbar-vs. spinal-onset pathology, local influence on neuronal dysfunction and their shared miRNA-depleted exosome trafficking. These causal and common features may have potential therapeutic implications in ALS. Future studies should clarify if astrocyte-derived sEVs are active players in ALS-related neuroinflammation and glial activation.

MicroRNA miR-155 is required for expansion of regulatory T cells to mediate robust pregnancy tolerance in mice

The immune-regulatory microRNA miR-155 is reduced in recurrent miscarriage, suggesting that miR-155 contributes to immune tolerance in pregnancy. Here we show miR-155 is induced in the uterine mucosa and draining lymph nodes (dLN) during the female immune response to male seminal fluid alloantigens. Mice with null mutation in miR-155 (miR-155^-/-) exhibited a reduced CD4⁺ T cell response after mating, with a disproportionate loss of CD25+FOXP3+ Treg cells. miR-155 deficiency impaired expansion of both peripheral and thymic Treg cells, distinguished by neuropilin-1 (NRP1), and fewer Treg cells expressed Ki67 proliferation marker and suppressive function marker CTLA4. Altered Treg phenotype distribution in miR-155^-/- mice was confirmed by t-distributed neighbor embedding (tSNE) analysis. Fewer dendritic cells (DCs) and macrophages trafficked to the dLN of miR-155^-/- mice, associated with lower CCR7 on DCs, and reduced uterine Ccl19 expression, implicating compromised antigen presentation in the stunted Treg cell response. miR-155^-/- mice exhibited elevated susceptibility to inflammation-induced fetal loss and fetal growth restriction compared with miR-155^+/+ controls, but outcomes were restored by transfer of wild-type Tregs. Thus miR-155 is a key regulator of immune adaptation to pregnancy and is necessary for sufficient Tregs to achieve robust pregnancy tolerance and protect against fetal loss.

Increased ISGylation in Cases of TBI-Exposed ALS Veterans

Veterans who have served in the military are at a nearly 60% greater risk of being diagnosed with amyotrophic lateral sclerosis (ALS). Literature reports suggest that a history of traumatic brain injury (TBI) may be a risk factor for ALS in veterans. However, no diagnostic biomarkers are available for identifying ALS risk/development in TBI-exposed veterans. Here, using a Wes assay, we show that ISGylation, a conjugated form of interferon-stimulated gene 15 protein, is significantly elevated in the lumbar spinal cords (SC-Ls) of TBI-ALS compared with ALS veterans without a previous history of TBI (nonTBI-ALS). Although not as striking as in TBI-ALS veterans, ISGylation is also increased in nonTBI-ALS compared with normal veterans. Notably, no changes in ISGylation were seen in occipital lobe samples obtained from the same patients, suggesting that elevated ISGylation is distinct to ALS disease-specific SC-Ls. Moreover, we detected increased ISGylation in cerebral spinal fluid samples of TBI-ALS veterans. Other results using cultured lymphocyte cell lines show a similar trend of increased ISGylation in ALS patients from the general population. Together, these data suggest that ISGylation could serve as a diagnostic biomarker for TBI-ALS veterans, nonTBI-ALS veterans, and nonveterans affected by ALS.

Expression study of candidate miRNAs and evaluation of their potential use as biomarkers of diabetic neuropathy

Aim: To evaluate the expression of candidate miRNAs in relation to diabetic polyneuropathy (DPN) and cardiovascular autonomic neuropathy (CAN). Materials & methods: The expression of six candidate miRNAs has been evaluated in 49 Type 2 diabetes patients with neurological evaluation. Results: A higher expression of miR-128a was seen in patients with DPN compared with those without DPN (p = 0.015). miR-155 and miR-499a seemed to be down-expressed in patients with DPN (p = 0.04 and p = 0.05, respectively). A lower expression of miR-155 (p = 0.05) was observed even in patients with CAN with respect to CAN-negative. A higher expression of miR-155 was associated with the rs767649 polymorphism variant allele compared with the wild-type allele (p = 0.03). Conclusion: miR-128a, miR-155 and miR-499a might be involved in diabetic neuropathies development.

High expression of JC polyomavirus-encoded microRNAs in progressive multifocal leukoencephalopathy tissues and its repressive role in virus replication

JC polyomavirus (JCPyV, JCV) causes progressive multifocal leukoencephalopathy (PML) in immunocompromised hosts. JCPyV replicates in oligodendrocytes within the brain tissue of patients with PML. The JCPyV genome encodes a microRNA (miRNA) in the region encoding the large T antigen. JCPyV-encoded miRNA (miR-J1) has been detected in the tissue and cerebrospinal fluid samples of patients with PML; however, there are no reports describing the localization of polyomavirus-encoded miRNA in histological samples of patients with virus-associated diseases. In the present study, we detected high miR-J1 expression in the nuclei of JCPyV-infected cells in PML tissue samples via in situ hybridization. Additionally, in situ hybridization also revealed the expression of BK polyomavirus (BKPyV, BKV)-encoded miRNA in lesions of BKPyV-associated nephropathy. In situ hybridization for miR-J1-5p and -3p showed positive signals in 24/25 (96%) of PML tissues that were positive for JCPyV by immunohistochemistry. Higher copy numbers of miR-J1 were detected in PML tissues than in non-PML tissues by real-time reverse transcription PCR. Next generation sequencing showed that miR-J1-5p, a mature miRNA of primary miRNA, was predominant in the lesions compared with miR-J1-3p, another mature miRNA. Deletion or mutation of miR-J1 in recombinant JCPyV promoted the production of JCPyV-encoded proteins in cells transfected with JCPyV DNA, suggesting that polyomavirus-encoded miRNA may have a repressive role in viral replication in PML tissues. In situ hybridization for viral miRNA may be a useful diagnostic tool for PML.

Aerobic Exercise Inhibits CUMS-Depressed Mice Hippocampal Inflammatory Response via Activating Hippocampal miR-223/TLR4/MyD88-NF-κB Pathway

Objective: To investigate the role of aerobic exercise in inhibiting chronic unpredictable mild stress (CUMS) depressed mice hippocampal inflammatory response and its potential mechanisms. Methods: Fifty-four male eight-week-old C57BL/6 mice were divided as control group (CG) (18 mice) and model group (36 mice). Model group mice were treated with 13 chronic stimulating factors for 28 days to set up the CUMS depression model. Neurobehavioral assessment was performed after modeling. The mice in the model group were randomly divided into the control model group (MG) and the aerobic exercise group (EG), with 18mice in each group. The EG group carried out the adaptive training of the running platform: 10 m/min, 0° slope, and increased by 10 minutes per day for 6 days. The formal training was carried for 8 weeks with 10 m/min speed, 0° slope, 60 min/d, 6 d/Week. After the training, a neurobehavioral assessment was performed, and hippocampus IL-1β and IL-10 protein levels were detected by ELISA. RT–PCR was used to detect the expression of miR-223 and TLR4, MyD88, and NF-κB in the hippocampus. Western blot was used to detect the expression of TLR4 and phosphorylated NF-κBp65 protein in the hippocampus. Results: The hippocampus function of CUMS depression model mice was impaired. The forced swimming and forced tail suspension time were significantly prolonged, and inflammatory factors IL-1β were significantly increased in the hippocampus. Aerobic exercise significantly improves CUMS-depressed mice hippocampal function, effectively reducing depressive behavior and IL-1β levels, and increasing IL-10 levels. Besides, aerobic exercise significantly upregulates the expression level of miR-223 and inhibits the high expression of TLR4, MyD88, and NF-κB. Conclusion: Aerobic exercise significantly increases the CUMS-depressed mice hippocampus expression of miR-223, and inhibits the downstream TLR4/MyD88-NF-κB signaling pathway and the hippocampal inflammatory response, which contributes to the improvement of the hippocampal function.

Epigenetic mechanisms of neurodegenerative diseases and acute brain injury

Epigenetic modifications are emerging as major players in the pathogenesis of neurodegenerative disorders and susceptibility to acute brain injury. DNA and histone modifications act together with non-coding RNAs to form a complex gene expression machinery that adapts the brain to environmental stressors and injury response. These modifications influence cell-level operations like neurogenesis and DNA repair to large, intricate processes such as brain patterning, memory formation, motor function and cognition. Thus, epigenetic imbalance has been shown to influence the progression of many neurological disorders independent of aberrations in the genetic code. This review aims to highlight ways in which epigenetics applies to several commonly researched neurodegenerative diseases and forms of acute brain injury as well as shed light on the benefits of epigenetics-based treatments.

Analgesic treatment limits surrogate parameters for early stress and pain response after experimental subarachnoid hemorrhage

Background

In animal research, authorities require a classification of anticipated pain levels and a perioperative analgesia protocol prior to approval of the experiments. However, data on this topic is rare and so is the reported use of analgesics. We determined surrogate parameters of pain and general well-being after subarachnoid hemorrhage (SAH), as well as the potential for improvement by different systemic analgesia paradigms. Brain injury was induced by filament perforation to mimic SAH. Sham-operated mice were included as surgical control groups with either neck or no-neck preparation. Mice with controlled cortical impact (CCI) injury were included as a control group with traumatic brain injury (TBI), but without neck preparation. Mice were randomized to buprenorphine, carprofen, meloxicam, or vehicle treatment. 24 h after SAH, CCI or sham surgery, pain and stress levels were assessed with a visual assessment score and the amount of food intake was recorded.

Results

Neck preparation, which is required to expose the surgical field for SAH induction, already increased pain/stress levels and sham surgeries for both CCI and SAH reduced food intake. Pain/stress levels were higher and food intake was lower after SAH compared with CCI. Pain/stress levels after CCI without analgesic treatment were similar to levels after SAH sham surgery. Pain treatment with buprenorphine was effective to reduce pain after SAH, whereas lower pain/stress intensity levels after CCI were not improved.

Conclusion

This study emphasizes the importance of pain and stress assessment after surgeries and the efficacy of buprenorphine to improve pain and comfort levels after experimental SAH.

miR-155-5p Promotes Dorsal Root Ganglion Neuron Axonal Growth in an Inhibitory Microenvironment via the cAMP/PKA Pathway

Sensory dysfunction post spinal cord injury causes patients great distress. Sciatic nerve conditioning injury (SNCI) has been shown to restore sensory function after spinal cord dorsal column injury (SDCL); however, the underlying mechanism of this recovery remains unclear. We performed a microarray assay to determine the associated miRNAs that might regulate the process of SNCI promoting SDCL repair. In total, 13 miRNAs were identified according to our inclusion criteria, and RT-qPCR was used to verify the microarray results. Among the 13 miRNAs, the miR-155-5p levels were decreased at 9 h, 3 d, 7 d, 14 d, 28 d, 2 m and 3 m timepoints in the SDCL group, while the SNCI group had a smaller decrease. Thus, miR-155-5p was chosen for further study after a literature review and an analysis with the TargetScan online tool. Specifically, miR-155-5p targets PKI-α, and the expression pattern of PKI-α was opposite that of miR-155-5p in both the SDCL and SNCI groups. Interestingly, miR-155-5p could promote dorsal root ganglion (DRG) neuron axon growth via the cAMP/PKA pathway and in a TNF-α, IL-1β or MAG inhibitory microenvironment in vitro. Furthermore, miR-155-5p could regulate the cAMP/PKA pathway and promote sensory conduction function recovery post dorsal column injury as detected by NF-200 immunohistochemistry, somatosensory-evoked potentials, BBB scale and tape removal test. Collectively, our results demonstrated that miR-155-5p participates in the molecular mechanism by which SNCI promotes the repair of SDCL and that upregulated miR-155-5p can repair SDCL by enhancing DRG neuron axon growth via the cAMP/PKA pathway. These findings suggest a novel treatment target for spinal cord injury.

Neutral Sphingomyelinase Inhibition Alleviates LPS-Induced Microglia Activation and Neuroinflammation after Experimental Traumatic Brain Injury

Neuroinflammation is one of the key secondary injury mechanisms triggered by traumatic brain injury (TBI). Microglial activation, a hallmark of brain neuroinflammation, plays a critical role in regulating immune responses after TBI and contributes to progressive neurodegeneration and neurologic deficits following brain trauma. Here we evaluated the role of neutral sphingomyelinase (nSMase) in microglial activation by examining the effects of the nSMase inhibitors altenusin and GW4869 in vitro (using BV2 microglia cells and primary microglia), as well as in a controlled cortical injury (CCI) model in adult male C57BL/6 mice. Pretreatment of altenusin or GW4869 prior to lipopolysaccharide (LPS) stimulation for 4 or 24 hours, significantly downregulated gene expression of the pro-inflammatory mediators TNF-α, IL-1β, IL-6, iNOS, and CCL2 in microglia and reduced the release of nitric oxide and TNF-α These nSMase inhibitors also attenuated the release of microparticles and phosphorylation of p38 MAPK and ERK1/2. In addition, altenusin pretreatment also reduced the gene expression of multiple inflammatory markers associated with microglial activation after experimental TBI, including TNF-α, IL-1β, IL-6, iNOS, CCL2, CD68, NOX2, and p22phox Overall, our data demonstrate that nSMase inhibitors attenuate multiple inflammatory pathways associated with microglial activation in vitro and after experimental TBI. Thus, nSMase inhibitors may represent promising therapeutics agents targeting neuroinflammation.

Comparison of serum and saliva miRNAs for identification and characterization of mTBI in adult mixed martial arts fighters

Traumatic brain injury (TBI) is a major cause of death and disability worldwide, with mild TBI (mTBI) accounting for 85% of cases. mTBI is also implicated in serious long-term sequelae including second impact syndrome and chronic traumatic encephalopathy. mTBI often goes undiagnosed due to delayed symptom onset and limited sensitivity of conventional assessment measures compared with severe TBI. Current efforts seek to identify accurate and reliable non-invasive biomarkers associated with functional measures relevant to long-term outcomes. Here we evaluated the utility of serum and salivary microRNAs (miRNAs) to serve as sensitive and specific peripheral biomarkers of possible mTBI. Our primary objectives were to establish the relationship between peripheral measures of miRNA, objective quantification of head impacts, and sensitive indices of balance and cognitive function in healthy young adult athletes. A secondary objective was to compare the sensitivity of miRNA versus commonly used blood-based protein biomarkers. 50 amateur mixed martial arts (MMA) fighters participated. 216 saliva and serum samples were collected at multiple time points, both pre- and post-fight. Levels of 10 serum proteins were compared in a subset of the fighters (n = 24). Levels of miRNAs were obtained by next generation sequencing. Functional outcomes were evaluated using a computerized assessment system that measured cognitive performance, body sway, and combined cognitive performance and body sway during dual task completion. Data were analyzed using multivariate logistic regression for predictive classification, analysis of variance, correlation analysis and principal component analysis. We identified a subset of salivary and serum miRNAs that showed robust utility at predicting TBI likelihood and demonstrated quantitative associations with head impacts as well as cognitive and balance measures. In contrast, serum proteins demonstrated far less utility. We also found that the timing of the responses varies in saliva and serum, which is a critical observation for biomarker studies to consider.

Inhibition of miR-155 Limits Neuroinflammation and Improves Functional Recovery After Experimental Traumatic Brain Injury in Mice

Micro-RNAs (miRs) are short, noncoding RNAs that negatively regulate gene expression at the post-transcriptional level and have been implicated in the pathophysiology of secondary damage after traumatic brain injury (TBI). Among miRs linked to inflammation, miR-155 has been implicated as a pro-inflammatory factor in a variety of organ systems. We examined the expression profile of miR-155, following experimental TBI (controlled cortical impact) in adult male C57Bl/6 mice, as well as the effects of acute or delayed administration of a miR-155 antagomir on post-traumatic neuroinflammatory responses and neurological recovery. Trauma robustly increased miR-155 expression in the injured cortex over 7 days. Similar TBI-induced miR-155 expression changes were also found in microglia/macrophages isolated from the injured cortex at 7 days post-injury. A miR-155 hairpin inhibitor (antagomir; 0.5 nmol), administered intracerebroventricularly (ICV) immediately after injury, attenuated neuroinflammatory markers at both 1 day and 7 days post-injury and reduced impairments in spatial working memory. Delayed ICV infusion of the miR-155 antagomir (0.5 nmol/day), beginning 24 h post-injury and continuing for 6 days, attenuated neuroinflammatory markers at 7 days post-injury and improved motor, but not cognitive, function through 28 days. The latter treatment limited NADPH oxidase 2 expression changes in microglia/macrophages in the injured cortex and reduced cortical lesion volume. In summary, TBI causes a robust and persistent neuroinflammatory response that is associated with increased miR-155 expression in microglia/macrophages, and miR-155 inhibition reduces post-traumatic neuroinflammatory responses and improves neurological recovery. Thus, miR-155 may be a therapeutic target for TBI-related neuroinflammation.

MiR-206-3p alleviates chronic constriction injury-induced neuropathic pain through targeting HDAC4

It was identified that microRNAs were involved in the regulation of chronic neuropathic pain. However, the role of miR-206-3p in neuropathic pain was still unclear. In the current study, the role of miR-206-3p, a type of mature miR-206, in neuropathic pain was investigated. The potential mechanisms were also explored. We found that the expression of miR-206-3p decreased in the dorsal root ganglion (DRG) of chronic constriction sciatic nerve injury (CCI) rats, whereas the While histone deacetylase 4 (HDAC4) level increased. Further exploration showed that administration of a miR-206-3p mimic alleviated neuropathic pain and reduced the level of HDAC4, a predicted target of miR-206-3p. Overexpression of HDAC4 attenuated the effects of miR-206-3p on neuropathic pain. Our data revealed a miR-206-3p-HDAC4 signal that played a potentially important role in CCI-induced neuropathic pain.

MicroRNA cluster miR199a/214 are differentially expressed in female and male rats following nicotine self-administration

Previous research has established sex differences associated with nicotine intake, however a significant gap in knowledge remains regarding the molecular mechanisms that govern these differences at the transcriptional level. One critical regulator of transcription are microRNAs (miRNAs). miRNAs are a family of non-coding RNAs that regulate an array of important biological functions altered in several disease states, including neuroadaptive changes within the brain associated with drug dependence. We examined the prefrontal cortex (PFC) from male and female Sprague-Dawley rats following self-administration (22 days) of nicotine or yoked saline controls using next generation RNA-Sequencing (RNA-Seq) technology and found an array of miRNAs to be significantly and differentially regulated by nicotine self-administration. Of these, we found the expression of miR-199a and 214, which are expressed on the same cluster of chromosome 1, to be upregulated in the female rats exposed to nicotine; upregulation in this group was further validated by real time polymerase chain reaction (RT-PCR). Bioinformatics analysis to assess common targets of miR-199/214 identified Sirtuin 1 (SIRT1), a nicotinamide adenine dinucleotide (NAD)- dependent deacetylase that plays a role in apoptosis, neuron survival, and stress resistance. Using western-blot, we confirmed downregulation of SIRT1 and increased cleaved caspase 3 expression in the brains of nicotine-exposed female rats and no change in expression levels in the other groups. Collectively, our findings highlight a miR-199/214 regulatory network that, through SIRT1, may be associated with nicotine seeking in females which may serve as a potential therapeutic target for sex-specific treatment approaches.

Inflammation-associated miR-155 activates differentiation of muscular satellite cells

Tissue renewal and muscle regeneration largely rely on the proliferation and differentiation of muscle stem cells called muscular satellite cells (MuSCs). MuSCs are normally quiescent, but they are activated in response to various stimuli, such as inflammation. Activated MuSCs proliferate, migrate, differentiate, and fuse to form multinucleate myofibers. Meanwhile, inappropriate cues for MuSC activation induce premature differentiation and bring about stem cell loss. Recent studies revealed that stem cell regulation is disrupted in various aged tissues. We found that the expression of microRNA (miR)-155, which is an inflammation-associated miR, is upregulated in MuSCs of aged muscles, and this upregulation activates the differentiation process through suppression of C/ebpβ, which is an important molecule for maintaining MuSC self-renewal. We also found that Notch1 considerably repressed miR-155 expression, and loss of Notch1 induced miR-155 overexpression. Our findings suggest that miR-155 can act as an activator of muscular differentiation and might be responsible for accelerating aging-associated premature differentiation of MuSCs.

Interferons in Traumatic Brain and Spinal Cord Injury: Current Evidence for Translational Application

This review article provides a general perspective of the experimental and clinical work surrounding the role of type-I, type-II, and type-III interferons (IFNs) in the pathophysiology of brain and spinal cord injury. Since IFNs are themselves well-known therapeutic targets (as well as pharmacological agents), and anti-IFNs monoclonal antibodies are being tested in clinical trials, it is timely to review the basis for the repurposing of these agents for the treatment of brain and spinal cord traumatic injury. Experimental evidence suggests that IFN-α may play a detrimental role in brain trauma, enhancing the pro-inflammatory response while keeping in check astrocyte proliferation; converging evidence from genetic models and neutralization by monoclonal antibodies suggests that limiting IFN-α actions in acute trauma may be a suitable therapeutic strategy. Effects of IFN-β administration in spinal cord and brain trauma have been reported but remain unclear or limited in effect. Despite the involvement in the inflammatory response, the role of IFN-γ remains controversial: although IFN-γ appears to improve the outcome of traumatic spinal cord injury, genetic models have produced either beneficial or detrimental results. IFNs may display opposing actions on the injured CNS relative to the concentration at which they are released and strictly dependent on whether the IFN or their receptors are targeted either via administration of neutralizing antibodies or through genetic deletion of either the mediator or its receptor. To date, IFN-α appears to most promising target for drug repurposing, and monoclonal antibodies anti IFN-α or its receptor may find appropriate use in the treatment of acute brain or spinal cord injury.

Inhibition of miR-155 attenuates abdominal aortic aneurysm in mice by regulating macrophage-mediated inflammation

The aim of the present study was to identify abdominal aortic aneurysms (AAA)-associated miR-155 contributing to AAA pathology by regulating macrophage-mediated inflammation. Angiotensin II (AngII)-infused apolipoprotein E-deficient (ApoE-/-) mice and THP-1 cells model of miR-155 overexpression and deficiency were used in the experiments. The expression of miR-155 was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cytokines were evaluated using enzyme-linked immunoabsorbent assay (ELISA). Western blotting was used to measure the levels of MMP-2, MMP-9, iNOS, and monocyte chemoattractant protein (MCP)-1 proteins. Immunostaining and transwell were used to determine CD68, elastic collagen, proliferation, and migration of vascular smooth muscle cells (VSMCs). The results showed that miR-155 and cytokines were up-regulated in AAA patients or ApoE-/- mice. Overexpression of miR-155 enhanced MMP-2, MMP-9, iNOS, and MCP-1 levels, and stimulated the proliferation and migration of VSMCs. Meanwhile, inhibition of miR-155 had the opposite effect. In addition, histology demonstrated accumulation of CD68 and elastic collagen-positive areas significantly decreased in miR-155 antagomir injection group. In conclusion, the results of the present study suggest that inhibiting miR-155 is crucial to prevent the development of AAA by regulating macrophage inflammation.

Diagnosis and Assessment of Microbial Infections with Host and Microbial MicroRNA Profiles

MicroRNAs (miRNAs) encoded by viral genome or host have been found participating in host-microbe interactions. Differential expression profiles of miRNAs were shown linking to specific disease pathologies which indicated its potency as diagnostic/prognostic biomarkers of infectious disease. This was emphasized by the discovery of circulating miRNAs which were found to be remarkably stable in mammalian biofluids. Standardized methods of miRNA quantification including RNA isolation should be established before they will be ready for use in clinical practice.

Silencing rno-miR-155-5p in rat temporal lobe epilepsy model reduces pathophysiological features and cell apoptosis by activating Sestrin-3

Temporal lobe epilepsy (TLE) is a chronic neurological disease characterized by recurrent spontaneous seizures. MicroRNAs are dysregulated in various pathological conditions including epilepsy. Therefore, we hypothesized that the dysregulation of these microRNAs might also be associated with the pathogenesis of TLE. In this study, we found that a microRNA, hsa-miR-155-5p, was upregulated in patients with TLE post-surgery, and hence associated with clinical and pathological manifestations and seizure outcomes. We then used a rat model of experimental epilepsy induced by pilocarpine and revealed that the rat homologue was upregulated as well. Importantly, injection of an antagomiR of rno-miR-155-5p in vivo resulted in a reduction of the pathophysiological features associated with the status epilepticus, which was accompanied by decrease of apoptosis in the hippocampus. This effect was correlated with an increase in rat Sestrin-3 expression, which was a gene known to counteract oxidative stress. This rescue was also observed after injection of a lentivirus carrying the small interfering RNA of rat Sestrin-3 gene in the hippocampus. In addition, rno-miR-155-5p as well as rat Sestrin-3 mRNA and protein expression were partly dependent on oxidative stress induced by H₂O₂ in PC12 cells_. Taken together, our data suggest that rno-miR-155-5p is a potent post-transcriptional regulator of rat Sestrin-3 and it may be one of the molecular links between brain damage and increased risk for seizures during damage by oxidative stress.

A miRNA Signature for Cognitive Deficits and Alcohol Use Disorder in Persons Living with HIV/AIDS

HIV-associated neurocognitive disorders (HAND) affects more than half of persons living with HIV-1/AIDS (PLWHA). Identification of biomarkers representing the cognitive status of PLWHA is a critical step for implementation of successful cognitive, behavioral and pharmacological strategies to prevent onset and progression of HAND. However, the presence of co-morbidity factors in PLWHA, the most common being substance abuse, can prevent the identification of such biomarkers. We have optimized a protocol to profile plasma miRNAs using quantitative RT-qPCR and found a miRNA signature with very good discriminatory ability to distinguish PLWHA with cognitive impairment from those without cognitive impairment. Here, we have evaluated this miRNA signature in PLWHA with alcohol use disorder (AUD) at LSU Health Sciences Center (LSUHSC). The results show that AUD is a potential confounding factor for the miRNAs associated with cognitive impairment in PLWHA. Furthermore, we have investigated the miRNA signature associated with cognitive impairment in an independent cohort of PLWHA using plasma samples from the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) program. Despite differences between the two cohorts in socioeconomic status, AUD, and likely misuse of illicit or prescription drugs, we validated a miRNA signature for cognitive deficits found at LSUHSC in the CHARTER samples.