Neuronal Development-Related miRNAs as Biomarkers for Alzheimer's Disease, Depression, Schizophrenia and Ionizing Radiation Exposure

Impact of miR-29c-3p in the Nucleus Accumbens on Methamphetamine-Induced Behavioral Sensitization and Neuroplasticity-Related Proteins

Methamphetamine (METH) abuse inflicts both physical and psychological harm. While our previous research has established the regulatory role of miR-29c-3p in behavior sensitization, the underlying mechanisms and target genes remain incompletely understood. In this study, we employed the isobaric tags for relative and absolute quantitation (iTRAQ) technique in conjunction with Ingenuity pathway analysis (IPA) to probe the putative molecular mechanisms of METH sensitization through miR-29c-3p inhibition. Through a microinjection of AAV-anti-miR-29c-3p into the nucleus accumbens (NAc) of mice, we observed the attenuation of METH-induced locomotor effects. Subsequent iTRAQ analysis identified 70 differentially expressed proteins (DEPs), with 22 up-regulated potential target proteins identified through miR-29c-3p target gene prediction and IPA analysis. Our focus extended to the number of neuronal branches, the excitatory synapse count, and locomotion-related pathways. Notably, GPR37, NPC1, and IREB2 emerged as potential target molecules for miR-29c-3p regulation, suggesting their involvement in the modulation of METH sensitization. Quantitative PCR confirmed the METH-induced aberrant expression of Gpr37, Npc1, and Ireb2 in the NAc of mice. Specifically, the over-expression of miR-29c-3p led to a significant reduction in the mRNA level of Gpr37, while the inhibition of miR-29c-3p resulted in a significant increase in the mRNA level of Gpr37, consistent with the regulatory principle of miRNAs modulating target gene expression. This suggests that miR-29c-3p potentially influences METH sensitization through its regulation of neuroplasticity. Our research indicates that miR-29c-3p plays a crucial role in regulating METH-induced sensitization, and it identified the potential molecular of miR-29c-3p in regulating METH-induced sensitization.

Radioprotective effect of Ginkgolide B on brain: the mediating role of DCC/MST1 signaling

PURPOSE

The risk of brain exposure to ionizing radiation increases gradually due to the extensive application of nuclear technology in medical, industrial, and aerospace fields. Radiation-induced brain injury (RBI) is highly likely to cause a wide range of neurological complications, including schizophrenia, Alzheimer's disease (AD), depression. Ginkgolide B (GB) is one of the effective active components extracted from ginkgo biloba leaves, exerts protective effects on CNS, which is involved in the regulation of the Hippo signaling pathway. MST1, as one of the core kinases of the Hippo pathway, participated in regulating cell proliferation, differentiation, and apoptosis. However, it remains unclear whether GB attenuates radiation brain injury (RBI) and whether the radioprotective effect of GB refers to MST1 signaling. Hence, our study aimed to explore the radiation protection effect and the potential mechanism of GB.

MATERIALS AND METHODS

C57BL/6 mice were stimulated with an X-ray (20 Gy) to establish an RBI model. Then, morris water maze test (MWM) and step-down passive avoidance test (SDPAT) were used to assess the learning and memory function of mice. The open field test (OFT), tail suspension test (TST), and forced swimming test (FST) were used to assess changes in locomotor activity and hopelessness. Besides, X-ray-stimulated SH-SY5Y cells were used to verify the radioprotective effect of GB. Immunofluorescence double staining, Dihydroethidium (DHE), western blot, and flow cytometry were used to explore the role of DCC/MST1 signaling in RBI.

RESULTS

In this study, X-ray-treated mice exhibited cognitive impairment and depression-like behavior, which was ameliorated by GB treatment. GB also reduced the ROS production and the number of TUNEL-positive cells in the hippocampus. Moreover, GB increased the protein levels of p-AKT and Bcl2, while decreased the protein levels of MST1, p-p38, p-JNK, cleaved-caspase-3 and Bax both in vivo and in vitro. Additionally, exogenous Netrin-1 alleviated X-ray-induced ROS production and apoptosis, whereas knockout of Netrin-1 receptor DCC abolished the protective effect of GB.

CONCLUSION

Oxidative stress and MST1-mediated neuronal apoptosis participated in radiation-induced cognitive impairment and depression-like behaviors, and modulation of DCC by GB was an effective intervention against RBI.

Epigenetic regulation in major depression and other stress-related disorders: molecular mechanisms, clinical relevance and therapeutic potential

Major depressive disorder (MDD) is a chronic, generally episodic and debilitating disease that affects an estimated 300 million people worldwide, but its pathogenesis is poorly understood. The heritability estimate of MDD is 30-40%, suggesting that genetics alone do not account for most of the risk of major depression. Another factor known to associate with MDD involves environmental stressors such as childhood adversity and recent life stress. Recent studies have emerged to show that the biological impact of environmental factors in MDD and other stress-related disorders is mediated by a variety of epigenetic modifications. These epigenetic modification alterations contribute to abnormal neuroendocrine responses, neuroplasticity impairment, neurotransmission and neuroglia dysfunction, which are involved in the pathophysiology of MDD. Furthermore, epigenetic marks have been associated with the diagnosis and treatment of MDD. The evaluation of epigenetic modifications holds promise for further understanding of the heterogeneous etiology and complex phenotypes of MDD, and may identify new therapeutic targets. Here, we review preclinical and clinical epigenetic findings, including DNA methylation, histone modification, noncoding RNA, RNA modification, and chromatin remodeling factor in MDD. In addition, we elaborate on the contribution of these epigenetic mechanisms to the pathological trait variability in depression and discuss how such mechanisms can be exploited for therapeutic purposes.

Bioinformatics analysis and prediction of Alzheimer's disease and alcohol dependence based on Ferroptosis-related genes

Background

Alzheimer's disease (AD) is a neurodegenerative disease whose origins have not been universally accepted. Numerous studies have demonstrated the relationship between AD and alcohol dependence; however, few studies have combined the origins of AD, alcohol dependence, and programmed cell death (PCD) to analyze the mechanistic relationship between the development of this pair of diseases. We demonstrated in previous studies the relationship between psychiatric disorders and PCD, and in the same concerning neurodegeneration-related AD, we found an interesting link with the Ferroptosis pathway. In the present study, we explored the bioinformatic interactions between AD, alcohol dependence, and Ferroptosis and tried to elucidate and predict the development of AD from this aspect.

Methods

We selected the Alzheimer's disease dataset GSE118553 and alcohol dependence dataset GSE44456 from the Gene Expression Omnibus (GEO) database. Ferroptosis-related genes were gathered through Gene Set Enrichment Analysis (GSEA), Kyoto Encyclopedia of Genes and Genomes (KEGG), and relevant literature, resulting in a total of 88 related genes. For the AD and alcohol dependence datasets, we conducted Limma analysis to identify differentially expressed genes (DEGs) and performed functional enrichment analysis on the intersection set. Furthermore, we used ferroptosis-related genes and the DEGs to perform machine learning crossover analysis, employing Least Absolute Shrinkage and Selection Operator (LASSO) regression to identify candidate immune-related central genes. This analysis was also used to construct protein-protein interaction networks (PPI) and artificial neural networks (ANN), as well as to plot receiver operating characteristic (ROC) curves for diagnosing AD and alcohol dependence. We analyzed immune cell infiltration to explore the role of immune cell dysregulation in AD. Subsequently, we conducted consensus clustering analysis of AD using three relevant candidate gene models and examined the immune microenvironment and functional pathways between different subgroups. Finally, we generated a network of gene-gene interactions and miRNA-gene interactions using Networkanalyst.

Results

The crossover of AD and alcohol dependence DEG contains 278 genes, and functional enrichment analysis showed that both AD and alcohol dependence were strongly correlated with Ferroptosis, and then crossed them with Ferroptosis-related genes to obtain seven genes. Three candidate genes were finally identified by machine learning to build a diagnostic prediction model. After validation by ANN and PPI analysis, ROC curves were plotted to assess the diagnostic value of AD and alcohol dependence. The results showed a high diagnostic value of the predictive model. In the immune infiltration analysis, functional metabolism and immune microenvironment of AD patients were significantly associated with Ferroptosis. Finally, analysis of target genes and miRNA-gene interaction networks showed that hsa-mir-34a-5p and has-mir-106b-5p could simultaneously regulate the expression of both CYBB and ACSL4.

Conclusion

We obtained a diagnostic prediction model with good effect by comprehensive analysis, and validation of ROC in AD and alcohol dependence data sets showed good diagnostic, predictive value for both AD (AUC 0. 75, CI 0.91-0.60), and alcohol dependence (AUC 0.81, CI 0.95-0.68). In the consensus clustering grouping, we identified variability in the metabolic and immune microenvironment between subgroups as a likely cause of the different prognosis, which was all related to Ferroptosis function. Finally, we discovered that hsa-mir-34a-5p and has-mir-106b-5p could simultaneously regulate the expression of both CYBB and ACSL4.

Study on the Mechanism for SIRT1 during the Process of Exercise Improving Depression

The mechanism behind the onset of depression has been the focus of current research in the neuroscience field. Silent information regulator 1 (SIRT1) is a key player in regulating energy metabolism, and it can regulate depression by mediating the inflammatory response (e.g., nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β)), gene expression in the nucleus accumben (NAc) and CA1 region of the hippocampus (e.g., nescient helix-loop-helix2 (NHLH2), monoamine oxidase (MAO-A), and 5-Hydroxyindole-3-acetic acid (5-HIAA)), and neuronal regeneration in the CA3 region of the hippocampus. Exercise is an important means to improve energy metabolism and depression, but it remains to be established how SIRT1 acts during exercise and improves depression. By induction and analysis, SIRT1 can be activated by exercise and then improve the function of the hypothalamic-pituitary-adrenal (HPA) axis by upregulating brain-derived neurotrophic factors (BDNF), inhibit the inflammatory response (suppression of the NF-κB and TNF-α/indoleamine 2,3-dioxygenase (IDO)/5-Hydroxytryptamine (5-HT) pathways), and promote neurogenesis (activation of the insulin-like growth factor1 (IGF-1) and growth-associated protein-43 (GAP-43) pathways, etc.), thereby improving depression. The present review gives a summary and an outlook based on this finding and makes an analysis, which will provide a new rationale and insight for the mechanism by which exercise improves depression.

The role of microRNA-21 (miR-21) in pathogenesis, diagnosis, and prognosis of gastrointestinal cancers: A review

MicroRNAs (miRNAs) are small non-coding RNAs regulating the expression of several target genes. miRNAs play a significant role in cancer biology, as they can downregulate their corresponding target genes by impeding the translation of mRNA (at the mRNA level) as well as degrading mRNAs by binding to the 3'-untranslated (UTR) regions (at the protein level). miRNAs may be employed as cancer biomarkers. Therefore, miRNAs are widely investigated for early detection of cancers which can lead to improved survival rates and quality of life. This is particularly important in the case of gastrointestinal cancers, where early detection of the disease could substantially impact patients' survival. MicroRNA-21 (miR-21 or miRNA-21) is one of the most frequently researched miRNAs, where it is involved in the pathophysiology of cancer and the downregulation of several tumor suppressor genes. In gastrointestinal cancers, miR-21 regulates phosphatase and tensin homolog (PTEN), programmed cell death 4 (PDCD4), mothers against decapentaplegic homolog 7 (SMAD7), phosphatidylinositol 3-kinase /protein kinase B (PI3K/AKT), matrix metalloproteinases (MMPs), β-catenin, tropomyosin 1, maspin, and ras homolog gene family member B (RHOB). In this review, we investigate the functions of miR-21 in pathogenesis and its applications as a diagnostic and prognostic cancer biomarker in four different gastrointestinal cancers, including colorectal cancer (CRC), pancreatic cancer (PC), gastric cancer (GC), and esophageal cancer (EC).

Dual Effects of miR-181b-2-3p/SOX21 Interaction on Microglia and Neural Stem Cells after Gamma Irradiation

Ionizing radiation induces brain inflammation and the impairment of neurogenesis by activating microglia and inducing apoptosis in neurogenic zones. However, the causal relationship between microglial activation and the impairment of neurogenesis as well as the relevant molecular mechanisms involved in microRNA (miR) remain unknown. In the present study, we employed immunohistochemistry and real-time RT-PCR to study the microglial activation and miRNA expression in mouse brains. Real-time RT-PCR, western blot, ELISA, cell proliferation and cytotoxicity assay were used in BV2 and mouse neural stem cells (NSCs). In the mouse model, we found the acute activation of microglia at 1 day and an increased number of microglial cells at 1, 7 and 120 days after irradiation at postnatal day 3 (P3), day 10 (P10) and day 21 (P21), respectively. In cell models, the activation of BV2, a type of microglial cell line, was observed after gamma irradiation. Real-time RT-PCR analysis revealed a deceased expression of miR-181b-2-3p and an increased expression of its target SRY-related high-mobility group box transcription factor 21 (SOX21) in a dose- and time-dependent fashion. The results of the luciferase reporter assay confirmed that SOX21 was the target of miR-181b-2-3p. Furthermore, SOX21 knockdown by siRNA inhibited the activation of microglia, thereby suggesting that the direct interaction of 181b-2-3p with SOX21 might be involved in radiation-induced microglial activation and proliferation. Interestingly, the gamma irradiation of NSCs increased miR-181b-2-3p expression but decreased SOX21 mRNA, which was the opposite of irradiation-induced expression in BV2 cells. As irradiation reduced the viability and proliferation of NSCs, whereas the overexpression of SOX21 restored the impaired cell viability and promoted the proliferation of NSCs, the findings suggest that the radiation-induced interaction of miR-181b-2-3p with SOX21 may play dual roles in microglia and NSCs, respectively, leading to the impairment of brain neurogenesis.

Glutamate receptor 4 as a fluid biomarker for the diagnosis of psychiatric disorders

Psychiatric disorders are widely underreported diseases, especially in their early stages. So far, there is no fluid biomarker to confirm the diagnosis of these disorders. Proteomics data suggest the synaptic protein glutamate receptor 4 (GluR4), part of the AMPA receptor, as a potential diagnostic biomarker of major depressive disorder (MDD). A novel sandwich ELISA was established and analytically validated to detect GluR4 in cerebrospinal fluid (CSF) samples. A total of 85 subjects diagnosed with MDD (n = 36), bipolar disorder (BD, n = 12), schizophrenia (SCZ, n = 12) and neurological controls (CON, n = 25) were analysed. The data exhibited a significant correlation (r = 0.74; CI:0.62 to 0.82; p < 0.0001) with the antibody-free multiple reaction monitoring (MRM) mass spectrometry (MS) data. CSF GluR4 levels were lower in MDD (p < 0.002) and BD (p = 0.012) than in CON. Moreover, subjects with SCZ described a trend towards lower levels than CON (p = 0.13). The novel GluR4 ELISA may favour the clinical application of this protein as a potential diagnostic biomarker of psychiatric disorders and may facilitate the understanding of the pathophysiological mechanisms behind these disorders.

Medulloblastoma and Down Syndrome: An Extremely Rare Association

Medulloblastoma has a reduced incidence in Down syndrome (DS). This protective characteristic has not been clarified yet. Here, we report the second case of SHH medulloblastoma and DS documented in the literature. A complete surgery was performed followed by reduced craniospinal irradiation dose and adjuvant chemotherapy. No evidence of tumor recurrence was observed. The overall survival was 9.1 years. No family history or physical stigma of other hereditary predisposition syndrome was found. In the elucidation of this extremely rare association, future case reports play an important role in defining the spectrum of brain tumors and their peculiar features in DS.

Oroxylin A: A Promising Flavonoid for Prevention and Treatment of Chronic Diseases

There have been magnificent advancements in the understanding of molecular mechanisms of chronic diseases over the past several years, but these diseases continue to be a considerable cause of death worldwide. Most of the approved medications available for the prevention and treatment of these diseases target only a single gene/protein/pathway and are known to cause severe side effects and are less effective than they are anticipated. Consequently, the development of finer therapeutics that outshine the existing ones is far-reaching. Natural compounds have enormous applications in curbing several disastrous and fatal diseases. Oroxylin A (OA) is a flavonoid obtained from the plants Oroxylum indicum, Scutellaria baicalensis, and S. lateriflora, which have distinctive pharmacological properties. OA modulates the important signaling pathways, including NF-κB, MAPK, ERK1/2, Wnt/β-catenin, PTEN/PI3K/Akt, and signaling molecules, such as TNF-α, TGF-ꞵ, MMPs, VEGF, interleukins, Bcl-2, caspases, HIF-1α, EMT proteins, Nrf-2, etc., which play a pivotal role in the molecular mechanism of chronic diseases. Overwhelming pieces of evidence expound on the anti-inflammatory, anti-bacterial, anti-viral, and anti-cancer potentials of this flavonoid, which makes it an engrossing compound for research. Numerous preclinical and clinical studies also displayed the promising potential of OA against cancer, cardiovascular diseases, inflammation, neurological disorders, rheumatoid arthritis, osteoarthritis, etc. Therefore, the current review focuses on delineating the role of OA in combating different chronic diseases and highlighting the intrinsic molecular mechanisms of its action.

Microglia as Therapeutic Target for Radiation-Induced Brain Injury

Radiation-induced brain injury (RIBI) after radiotherapy has become an increasingly important factor affecting the prognosis of patients with head and neck tumor. With the delivery of high doses of radiation to brain tissue, microglia rapidly transit to a pro-inflammatory phenotype, upregulate phagocytic machinery, and reduce the release of neurotrophic factors. Persistently activated microglia mediate the progression of chronic neuroinflammation, which may inhibit brain neurogenesis leading to the occurrence of neurocognitive disorders at the advanced stage of RIBI. Fully understanding the microglial pathophysiology and cellular and molecular mechanisms after irradiation may facilitate the development of novel therapy by targeting microglia to prevent RIBI and subsequent neurological and neuropsychiatric disorders.

Mechanistic insights gained from cell and molecular analysis of the neuroprotective potential of bioactive natural compounds in an immortalized hippocampal cell line

Evaluating novel compounds for neuroprotective effects in animal models of traumatic brain injury (TBI) is a protracted, labor-intensive and costly effort. However, the present lack of effective treatment options for TBI, despite decades of research, shows the critical need for alternative methods for screening new drug candidates with neuroprotective properties. Because natural products have been a leading source of new therapeutic agents for human diseases, we used an in vitro model of stretch injury to rapidly assess pro-survival effects of three bioactive compounds, two isolated from natural products (clovanemagnolol [CM], vinaxanthone [VX]) and the third, a dietary compound (pterostilbene [PT]) found in blueberries. The stretch injury experiments were not used to validate drug efficacy in a comprehensive manner but used primarily, as proof-of-principle, to demonstrate that the neuroprotective potential of each bioactive agent can be quickly assessed in an immortalized hippocampal cell line in lieu of comprehensive testing in animal models of TBI. To gain mechanistic insights into potential molecular mechanisms of neuroprotective effects, we performed a pathway-specific PCR array analysis of the effects of CM on the rat hippocampus and microRNA sequencing analysis of the effects of VX and PT on cultured hippocampal progenitor neurons. We show that the neuroprotective properties of these natural compounds are associated with altered expression of several genes or microRNAs that have functional roles in neurodegeneration or cell survival. Our approach could help in quickly assessing multiple natural products for neuroprotective properties and expedite the process of new drug discovery for TBI therapeutics.

Plasma circulating micro-RNAs associated with alexithymia reflect a high overlap on neuropsychiatric outcomes

BACKGROUND

Alexithymia ("no word for feelings") is a personality feature that is common in patients with psychiatric disorders. However, little is known about biological causes and mechanism behind. Research so far focusses on genetic risk variants primary associated with depression, but analyses on epigenetic mechanisms are still missing.

METHODS

In a sample of n = 813 subjects from the "Study of Health in Pomerania" we analyzed the association between alexithymia and plasma circulating micro RNAs (miRNA). Significant miRNAs were compared to associations regarding depression and pathway analyses were performed.

RESULTS

Two miRNAs were significantly associated with at least one of the alexithymia scores (hsa-miR-324-3p, hsa-miR-33a-5p) and three miRNAs additionally revealed a strong association pattern to alexithymia (hsa-miR-106b-5p, hsa-miR-484, hsa-miR-25-3p). None of these miRNAs was significantly associated with depressive symptoms in our sample. Literature research showed that all of the miRNAs have been found in association with several neuropsychiatric phenotypes.

LIMITATIONS

Main limitations are the lack of a replication sample as well as the limited number of miRNAs analyzed.

CONCLUSIONS

This is the first analysis investigating the association between miRNAs and alexithymia. Results indicate that miRNAs are not specific for one psychiatric disorder but may influence biological mechanisms that are involved in various psychiatric conditions which might be relevant for future treatment options and improve the biological understanding of psychiatric conditions.

Exposure to a mixture of heavy metals induces cognitive impairment: Genes and microRNAs involved

Converging evidence demonstrates that microRNAs (miRNAs) play an important role in the etiology of cognitive impairment. Thus, we aim to: (i) identify the molecular mechanisms of heavy metals, particularly miRNAs involved in the development of cognitive impairment; and (ii) generate miRNA sponges to prevent them from binding with their target messenger RNAs. The Comparative Toxicogenomics Database (CTD; http://ctd.mdibl.org), MicroRNA ENrichment TURned NETwork (MIENTURNET, http://userver.bio.uniroma1.it/apps/mienturnet/) and the microRNA sponge generator and tester (miRNAsong, http://www.med.muni.cz/histology/miRNAsong) were used as the core data-mining approaches in the current study. We observed that lead acetate, arsenic, gold, copper, iron, and aluminum, as well as their mixtures, had significant effects on the development of cognitive impairment. Although prevalent genes obtained from investigated heavy metals of cognitive impairment were different, the "PI3K-Akt signaling pathway", "pathways of neurodegeneration-multiple diseases", "apoptosis", "apoptosis-multiple species", "p53 signaling pathway", "NF-kappa B signaling pathway", and "Alzheimer's disease pathway" were highlighted. The mixed heavy metals altered the genes BAX, CASP3, BCL2, TNF, and IL-1B, indicating the significance of apoptosis and pro-inflammatory cytokines in the pathogenesis of cognitive impairment and the possibility of targeting these genes in future neuroprotective therapy. In addition, we used a network-based approach to identify key genes, miRNAs, pathways, and diseases related to the development of cognitive impairment. We also found 16 significant miRNAs related to cognitive impairment (hsa-miR-1-3p, hsa-let-7a-5p, hsa-miR-9-5p, hsa-miR-16-5p, hsa-miR-17-5p, hsa-miR-20a-5p, hsa-miR-26a-5p, hsa-miR-26b-5p, hsa-miR-34a-5p, hsa-miR-101-3p, hsa-miR-106a-5p, hsa-miR-128-3p, hsa-miR-144-3p, hsa-miR-199a-3p, hsa-miR-204-5p, and hsa-miR-335-5p). Finally, we created and evaluated miRNA sponge sequences for these miRNAs in silico. Further studies, including in vivo and in vitro, are needed to assess the link between these genes, miRNAs, pathways, and cognitive impairment.

Altered White Matter and microRNA Expression in a Murine Model Related to Williams Syndrome Suggests That miR-34b/c Affects Brain Development via Ptpru and Dcx Modulation

Williams syndrome (WS) is a multisystem neurodevelopmental disorder caused by a de novo hemizygous deletion of ~26 genes from chromosome 7q11.23, among them the general transcription factor II-I (GTF2I). By studying a novel murine model for the hypersociability phenotype associated with WS, we previously revealed surprising aberrations in myelination and cell differentiation properties in the cortices of mutant mice compared to controls. These mutant mice had selective deletion of Gtf2i in the excitatory neurons of the forebrain. Here, we applied diffusion magnetic resonance imaging and fiber tracking, which showed a reduction in the number of streamlines in limbic outputs such as the fimbria/fornix fibers and the stria terminalis, as well as the corpus callosum of these mutant mice compared to controls. Furthermore, we utilized next-generation sequencing (NGS) analysis of cortical small RNAs' expression (RNA-Seq) levels to identify altered expression of microRNAs (miRNAs), including two from the miR-34 cluster, known to be involved in prominent processes in the developing nervous system. Luciferase reporter assay confirmed the direct binding of miR-34c-5p to the 3'UTR of PTPRU-a gene involved in neural development that was elevated in the cortices of mutant mice relative to controls. Moreover, we found an age-dependent variation in the expression levels of doublecortin (Dcx)-a verified miR-34 target. Thus, we demonstrate the substantial effect a single gene deletion can exert on miRNA regulation and brain structure, and advance our understanding and, hopefully, treatment of WS.

LMCD1 antisense RNA 1 is a newly identified long noncoding RNA

Long noncoding RNAs (lncRNAs) are one of the interesting fields in cancer researches. LncRNAs are generally dysregulated in many diseases. LMCD1 antisense RNA 1 (LMCD1-AS1) is a newly identified lncRNA with protumorigenic functions on tumor cells. LMCD1-AS1 expression is increased in hepatocellular carcinoma (HCC). LMCD1-AS1 is a sponge of miR-106b-5p activity. LMCD1-AS1 modulates the survival of osteosarcoma via targeting miR-106b-5p. LMCD1-AS1 and Sp1 are highly expressed in osteosarcoma. SP1 can bind to the promoter region of LMCD1-AS1, resulting in its overexpression in osteosarcoma. GLI2 is shown to bind to the LMCD1-AS1 promoter and is transcriptionally activated by LMCD1-AS1. LMCD1 acts as a miR-1287-5p sponge to increase GLI2 expression. LMCD1 is abundantly expressed in kidney tissue. Moreover, it is functionally involved in protein-protein interactions with transcriptional co-repressor activity, including regulation of the calcineurin-NFAT signaling cascade known to play a critical role in recovery from acute kidney injury (AKI). The E2F1/LMCD1-AS1/miR-345-5p/COL6A3 axis is a newly identified regulatory mechanism, which has a function in cholangiocarcinoma (CCA) tumorigenesis and progression and provides potential therapeutic targets for CCA. Also, LMCD1-AS1 functions in thyroid cancer (THCA) development. LMCD1-AS1 is overexpressed in THCA cells, and LMCD1-AS1 knockdown suppresses the malignant phenotypes of THCA cells. In THCA development, LMCD1-AS1 exerts protumorigenic function through sponging miR-1287-5p to increase GLI2 expression, constituting a feedback loop of LMCD1-AS1/miR-1287-5p/GLI2. In this review, the author focuses on the molecular mechanisms of newly identified long noncoding RNA LMCD1 antisense RNA 1 (LMCD1-AS1).

Neuroprotective Effects of Lycium barbarum Berry on Neurobehavioral Changes and Neuronal Loss in the Hippocampus of Mice Exposed to Acute Ionizing Radiation

Background: Brain exposure to ionizing radiation during the radiotherapy of brain tumor or metastasis of peripheral cancer cells to the brain has resulted in cognitive dysfunction by reducing neurogenesis in hippocampus. The water extract of Lycium barbarum berry (Lyc), containing water-soluble Lycium barbarum polysaccharides and flavonoids, can protect the neuronal injury by reducing oxidative stress and suppressing neuroinflammation.

Reseach Design: To demonstrate the long-term radioprotective effect of Lyc, we evaluated the neurobehavioral alterations and the numbers of NeuN, calbindin (CB), and parvalbumin (PV) immunopositive hippocampal neurons in BALB/c mice after acute 5.5 Gy radiation with/without oral administration of Lyc at the dosage of 10 g/kg daily for 4 weeks.

Results: The results showed that Lyc could improve irradiation-induced animal weight loss, depressive behaviors, spatial memory impairment, and hippocampal neuron loss. Immunohistochemistry study demonstrated that the loss of NeuN-immunopositive neuron in the hilus of the dentate gyrus, CB-immunopositive neuron in CA1 strata radiatum, lacunosum moleculare and oriens, and PV-positive neuron in CA1 stratum pyramidum and stratum granulosum of the dentate gyrus after irradiation were significantly improved by Lyc treatment.

Conclusion: The neuroprotective effect of Lyc on those hippocampal neurons may benefit the configuration of learning related neuronal networks and then improve radiation induced neurobehavioral changes such as cognitive impairment and depression. It suggests that Lycium barbarum berry may be an alternative food supplement to prevent radiation-induced neuron loss and neuropsychological disorders.

Exposure to X-rays Causes Depression-like Behaviors in Mice via HMGB1-mediated Pyroptosis

The widespread application of ionizing radiation in industrial and medical fields leads to the increased brain exposure to X-rays. Radiation brain injury (RBI) seriously affects health of patients by causing cognitive dysfunction and neuroinflammation. However, the link between X-ray exposure and depressive symptoms and their detailed underlying mechanisms have not been well studied. Herein, we investigated the potential depression-like behaviors in mice exposed to X-rays and then explored the role of HMGB1 in this injury. We found that X-ray stimulation induced the generation of reactive oxygen species (ROS) in the prefrontal cortex in a dose-dependent manner, leading to the occurrence of depression-like behaviors of the mice. Moreover, X-ray exposure increased the expression of HMGB1, activated NLRP3 inflammasome signaling pathway and microglial cells, and then facilitated the release of pro-inflammatory cytokines, resulting in the pyroptosis and neuron loss both in vivo and in vitro. Additionally, glycyrrhizin (Gly), which is a HMGB1 inhibitor, reversed X-ray-induced behavioral changes and neuronal damage. Our findings indicated that HMGB1-mediated pyroptosis was involved in radiation-induced depression.

Gene regulation by antisense transcription: A focus on neurological and cancer diseases

Advances in high-throughput sequencing over the past decades have led to the identification of thousands of non-coding RNAs (ncRNAs), which play a major role in regulating gene expression. One emerging class of ncRNAs is the natural antisense transcripts (NATs), the RNA molecules transcribed from the opposite strand of a protein-coding gene locus. NATs are known to concordantly and discordantly regulate gene expression in both cis and trans manners at the transcriptional, post-transcriptional, translational, and epigenetic levels. Aberrant expression of NATs can therefore cause dysregulation in many biological pathways and has been observed in many genetic diseases. This review outlines the involvements and mechanisms of NATs in the pathogenesis of various diseases, with a special emphasis on neurodegenerative diseases and cancer. We also summarize recent findings on NAT knockdown and/or overexpression experiments and discuss the potential of NATs as promising targets for future gene therapies.

Early Life Irradiation-Induced Hypoplasia and Impairment of Neurogenesis in the Dentate Gyrus and Adult Depression Are Mediated by MicroRNA- 34a-5p/T-Cell Intracytoplasmic Antigen-1 Pathway

Early life radiation exposure causes abnormal brain development, leading to adult depression. However, few studies have been conducted to explore pre- or post-natal irradiation-induced depression-related neuropathological changes. Relevant molecular mechanisms are also poorly understood. We induced adult depression by irradiation of mice at postnatal day 3 (P3) to reveal hippocampal neuropathological changes and investigate their molecular mechanism, focusing on MicroRNA (miR) and its target mRNA and protein. P3 mice were irradiated by γ-rays with 5Gy, and euthanized at 1, 7 and 120 days after irradiation. A behavioral test was conducted before the animals were euthanized at 120 days after irradiation. The animal brains were used for different studies including immunohistochemistry, CAP-miRSeq, Real-Time Quantitative Reverse Transcription PCR (qRT-PCR) and western blotting. The interaction of miR-34a-5p and its target T-cell intracytoplasmic antigen-1 (Tia1) was confirmed by luciferase reporter assay. Overexpression of Tia1 in a neural stem cell (NSC) model was used to further validate findings from the mouse model. Irradiation with 5 Gy at P3 induced depression in adult mice. Animal hippocampal pathological changes included hypoplasia of the infrapyramidal blade of the stratum granulosum, aberrant and impaired cell division, and neurogenesis in the dentate gyrus. At the molecular level, upregulation of miR-34a-5p and downregulation of Tia1 mRNA were observed in both animal and neural stem cell models. The luciferase reporter assay and gene transfection studies further confirmed a direct interaction between miR-43a-5p and Tia1. Our results indicate that the early life γ-radiation-activated miR-43a-5p/Tia1 pathway is involved in the pathogenesis of adult depression. This novel finding may provide a new therapeutic target by inhibiting the miR-43a-5p/Tia1 pathway to prevent radiation-induced pathogenesis of depression.

Spatiotemporal dynamics of γH2AX in the mouse brain after acute irradiation at different postnatal days with special reference to the dentate gyrus of the hippocampus

Gamma H2A histone family member X (γH2AX) is a molecular marker of aging and disease. However, radiosensitivity of the different brain cells, including neurons, glial cells, cells in cerebrovascular system, epithelial cells in pia mater, ependymal cells lining the ventricles of the brain in immature animals at different postnatal days remains unknown. Whether radiation-induced γH2AX foci in immature brain persist in adult animals still needs to be investigated. Hence, using a mouse model, we showed an extensive postnatal age-dependent induction of γH2AX foci in different brain regions at 1 day after whole body gamma irradiation with 5Gy at postnatal day 3 (P3), P10 and P21. P3 mouse brain epithelial cells in pia mater, glial cells in white matter and cells in cerebrovascular system were more radiosensitive at one day after radiation exposure than those from P10 and P21 mice. Persistent DNA damage foci (PDDF) were consistently demonstrated in the brain at 120 days and 15 months after irradiation at P3, P10 and P21, and these mice had shortened lifespan compared to the age-matched control. Our results suggest that early life irradiation-induced PDDF at later stages of animal life may be related to the brain aging and shortened life expectancy of irradiated animals.

SRY-Box 21 Antisense RNA 1 Knockdown Diminishes Amyloid Beta25-35-Induced Neuronal Damage by miR-132/PI3K/AKT Pathway

Our study aimed to explore the function and mechanism of action of long noncoding RNA (lncRNA) SRY-Box 21 antisense RNA 1 (SOX21-AS1) in amyloid beta_25-35 (Aβ_25-35)-induced neuronal damage. To induce neuronal damage, neuronal cells and differentiated IMR-32 neuroblastoma cells were challenged by Aβ_25-35. SOX21-AS1 and miR-132 quantities were detected by quantitative reverse transcription polymerase chain reaction. Cell damage was evaluated by detecting the changes of cell viability, apoptosis, and oxidative stress. Cell viability was measured using cell counting kit-8. Cell apoptosis was evaluated by flow cytometry and caspase-3 activity. The oxidative stress was analyzed by reactive oxygen species level. The expression of proteins associated with the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway was examined by western blot. SOX21-AS1 abundance was up-regulated in Aβ_25-35-challenged neuronal cells. Silencing of SOX21-AS1 attenuated Aβ_25-35-induced viability reduction and promotion of apoptosis and oxidative stress, suggesting that silencing of SOX21-AS1 repressed Aβ_25-35-induced neuronal damage. miR-132 quantity was reduced in Aβ_25-35-challenged neuronal cells, and negatively controlled by SOX21-AS1. miR-132 knockdown abolished the effect of SOX21-AS1 silencing on Aβ_25-35-induced neuronal damage, indicating that SOX21-AS1 controls Aβ_25-35-induced neuronal damage via regulating miR-132. The PI3K/AKT signaling was repressed in Aβ_25-35-challenged cells, but this effect was counteracted upon overexpression of miR-132. In conclusion, SOX21-AS1 knockdown mitigated Aβ_25-35-dependent neuronal cell damage by promoting miR-132/PI3K/AKT pathway.

MicroRNA-489-3p plays a significant role in congenital hypothyroidism through regulating neuronal cell apoptosis via targeting translationally controlled tumor protein 1

Accumulating reports have indicated that congenital hypothyroidism (CH) is an endocrine disorder caused by underdeveloped thyroid gland or thyroid dyshormonogenesis. It has been also reported that certain microRNAs (miRNAs) may exert protective effects against the development of CH. However, whether miR-489-3p regulates CH progression remains unclear. The aim of the present study was to investigate the effects of miR-489-3p on CH and elucidate the underlying mechanisms. Therefore, Sprague Dawley rats were injected with propylthiouracil (50 mg/day) to establish a CH model. Reverse transcription-quantitative PCR (RT-qPCR) assay demonstrated that miR-489-3p was upregulated in the hippocampal tissues of CH rats. Furthermore, the TargetScan software was employed to predict the target gene of miR-489-3p, and a dual luciferase reporter assay revealed that translationally controlled tumor protein 1 (TPT1) was directly targeted by miR-489-3p. Additionally, RT-qPCR and western blot assays suggested that TPT1 was markedly downregulated in the hippocampal tissues of CH rats compared with control rats. In addition, inhibitor control, miR-489-3p inhibitor, control-shRNA or TPT1-shRNA were injected into CH rats. The results of the open-field and forced swimming tests revealed that miR-489-3p inhibitor notably improved the behavior of CH rats. Flow cytometry was applied to explore the effects of miR-489-3p inhibitor on neuronal cell apoptosis, and the findings indicated that miR-489-3p inhibitor attenuated CH-induced neuronal cell apoptosis, whereas these effects were reversed by treatment with miR-489-3p inhibitor and TPT1-shRNA. Finally, the function of miR-489-3p in neuronal cells was investigated in vitro. Neuronal cell viability, apoptosis and the expression of apoptosis-related proteins were determined using MTT assay, flow cytometry and western blot analysis, respectively. The results demonstrated that miR-489-3p inhibitor enhanced cell viability, suppressed apoptosis and upregulated Pim-3, phosphorylated (p)-Bad (Ser112) and Bcl-xL expression. Rescue experiments indicated that these effects were reversed following silencing of TPT1. Taken together, the findings of the present study demonstrated that miR-489-3p inhibitor could relieve CH-induced neurological damage through regulating TPT1 expression.

MicroRNA Alterations in Induced Pluripotent Stem Cell-Derived Neurons from Bipolar Disorder Patients: Pathways Involved in Neuronal Differentiation, Axon Guidance, and Plasticity

Bipolar disorder (BP) is a complex psychiatric condition characterized by severe fluctuations in mood for which underlying pathological mechanisms remain unclear. Family and twin studies have identified a hereditary component to the disorder, but a single causative gene (or set of genes) has not been identified. MicroRNAs (miRNAs) are small, noncoding RNAs ∼20 nucleotides in length, that are responsible for the posttranslational regulation of multiple genes. They have been shown to play important roles in neural development as well as in the adult brain, and several miRNAs have been reported to be dysregulated in postmortem brain tissue isolated from bipolar patients. Because there are no viable cellular models to study BP, we have taken advantage of the recent discovery that somatic cells can be reprogrammed to pluripotency then directed to form the full complement of neural cells. Analysis of RNAs extracted from Control and BP patient-derived neurons identified 58 miRNAs that were differentially expressed between the two groups. Using quantitative polymerase chain reaction we validated six miRNAs that were elevated and two miRNAs that were expressed at lower levels in BP-derived neurons. Analysis of the targets of the miRNAs indicate that they may regulate a number of cellular pathways, including axon guidance, Mapk, Ras, Hippo, Neurotrophin, and Wnt signaling. Many are involved in processes previously implicated in BP, such as cell migration, axon guidance, dendrite and synapse development, and function. We have validated targets of several different miRNAs, including AXIN2, BDNF, RELN, and ANK3 as direct targets of differentially expressed miRNAs using luciferase assays. Identification of pathways altered in patient-derived neurons suggests that disruption of these regulatory networks that may contribute to the complex phenotypes in BP.

Gene biomarker discovery at different stages of Alzheimer using gene co-expression network approach

Alzheimer's disease (AD) is a chronic neurodegenerative disorder. It is the most common type of dementia that has remained as an incurable disease in the world, which destroys the brain cells irreversibly. In this study, a systems biology approach was adopted to discover novel micro-RNA and gene-based biomarkers of the diagnosis of Alzheimer's disease. The gene expression data from three AD stages (Normal, Mild Cognitive Impairment, and Alzheimer) were used to reconstruct co-expression networks. After preprocessing and normalization, Weighted Gene Co-Expression Network Analysis (WGCNA) was used on a total of 329 samples, including 145 samples of Alzheimer stage, 80 samples of Mild Cognitive Impairment (MCI) stage, and 104 samples of the Normal stage. Next, three gene-miRNA bipartite networks were reconstructed by comparing the changes in module groups. Then, the functional enrichment analyses of extracted genes of three bipartite networks and miRNAs were done, respectively. Finally, a detailed analysis of the authentic studies was performed to discuss the obtained biomarkers. The outcomes addressed proposed novel genes, including MBOAT1, ARMC7, RABL2B, HNRNPUL1, LAMTOR1, PLAGL2, CREBRF, LCOR, and MRI1and novel miRNAs comprising miR-615-3p, miR-4722-5p, miR-4768-3p, miR-1827, miR-940 and miR-30b-3p which were related to AD. These biomarkers were proposed to be related to AD for the first time and should be examined in future clinical studies.