The Emerging Roles of the β-Secretase BACE1 and the Long Non-coding RNA BACE1-AS in Human Diseases: A Focus on Neurodegenerative Diseases and Cancer

Navigating the complexities of neuronal signaling and targets in neurological disorders: From pathology to therapeutics

Neurological disorders arising from structural and functional disruptions in the nervous system present major global health challenges. This review examines the intricacies of various cellular signaling pathways, including Nrf2/Keap1/HO-1, SIRT-1, JAK/STAT3/mTOR, and BACE-1/gamma-secretase/MAPT, which play pivotal roles in neuronal health and pathology. The Nrf2-Keap1 pathway, a key antioxidant response mechanism, mitigates oxidative stress, while SIRT-1 contributes to mitochondrial integrity and inflammation control. Dysregulation of these pathways has been identified in neurodegenerative and neuropsychiatric disorders, including Alzheimer's and Parkinson's diseases, characterized by inflammation, protein aggregation, and mitochondrial dysfunction. Additionally, the JAK/STAT3 signaling pathway emphasizes the connection between cytokine responses and neuroinflammation, further compounding disease progression. This review explores the crosstalk among these signaling networks, elucidating how their disruption leads to neuronal decline. It also addresses the dual roles of these pathways, presenting challenges in targeting them for therapeutic purposes. Despite the potential benefits of activating neuroprotective pathways, excessive stimulation may cause deleterious effects, including tumorigenesis. Future research should focus on designing multi-targeted therapies that enhance the effectiveness and safety of treatments, considering individual variabilities and the obstacles posed by the blood-brain barrier to drug delivery. Understanding these complex signaling interactions is crucial for developing innovative and effective neuroprotective strategies that could significantly improve the management of neurological disorders.

Pea Peptide Modulates Abnormal Aβ Production in PC12 Cells Induced by Lead Exposure

Lead (Pb) exposure poses significant health risks, particularly in neurodegenerative diseases such as Alzheimer's disease (AD). This study investigates the neuroprotective effects of pea peptide (PP4) on PC12 cells exposed to Pb. Using Cell Counting Kit-8 (CCK-8), pretreatment with PP4 at 50 and 200 µM concentrations significantly improved cell viability compared to Pb-only treated cells (P < 0.05), indicating a protective effect. Moreover, Pb exposure led to increased Amyloid Precursor Protein (APP) expression at 10 and 20 µM after 24 h (P < 0.05), while β-site amyloid Precursor Protein Cleaving Enzyme 1 (BACE1) levels were elevated across all concentrations tested (P < 0.05). We established that PP4 can mitigate Pb-induced cytotoxicity and reduce the expression of APP and BACE1 by activating the Phosphoinositide 3-kinase / Protein Kinase (PI3K/AKT) signaling pathway. This study highlights the potential of PP4 as a therapeutic agent in preventing neurotoxic damage associated with lead exposure, suggesting a novel approach for the management of AD.

In Silico and In Vitro Evaluation of Quinoline Derivatives as Potential Inhibitors of AChE, BACE1, and GSK3β for Neurodegenerative Diseases Treatment

Neurodegenerative diseases are characterized by the structural and functional loss of neurons, which impacts populations worldwide. Enzymes such as acetylcholinesterase (AChE), beta-site APP cleaving enzyme-1 (BACE1), and glycogen synthase kinase 3-beta (GSK3β) are implicated in their progression. Therefore, developing compounds that inhibit these enzymes is relevant for treating these conditions. This study investigated the potential of quinoline analogs as multitarget enzyme inhibitors through in silico and in vitro assays. In silico analyses highlighted one of the derivatives as the most potent inhibitor for all proteins. In vitro assays confirmed that the quinoline derivatives modulated the activity of the three targets. The best derivative in silico also exhibited significant AChE inhibition of 94.6 %. For GSK3β and BACE1, four derivatives, with quinoline linked to the sulfonamide nitrogen, showed inhibition values above 40 %. Two of them demonstrated no cytotoxicity for human glioblastoma cell proliferation, and the most potent was noncytotoxic at 7.8 and 3.9 μg mL-1. In murine fibroblasts, the most potent derivative showed no cytotoxicity, unlike its effect on glioblastoma cells. Similarly, other derivatives were noncytotoxic at concentrations less than 62.5 μg mL-1. These findings highlight one of the derivatives as promising multitarget enzyme inhibitors for the treatment of neurodegenerative diseases.

Exploring the Potential of tsRNA as Biomarkers for Diagnosis and Treatment of Neurogenetic Disorders

tRNA-derived small RNA (tsRNA) is a recently discovered small non-coding RNA (ncRNA) molecule that widely exists in prokaryotic and eukaryotic transcriptomes and is produced by specific cleavage of mature tRNA or precursor tRNA. In recent years, with the development of high-throughput sequencing technology, tsRNA has been found to have a variety of biological functions, including gene expression regulation, stress signal activation, etc. In addition, it has been found that these molecules are abnormally expressed in various diseases and participate in various pathological processes, which play an important role. At present, more and more studies have shown that the expression level of tsRNA changes significantly during the development of neurogenetic diseases. This review provides an overview of the classification and biological functions of tsRNAs, with a particular emphasis on their roles in neurogenetic disorders and their potential as diagnostic biomarkers and therapeutic targets. Despite the nascent stage of tsRNA research, their relevance to the diagnosis and treatment of neurogenetic diseases warrants further investigation.

Upregulation of LncRNAs G2E3-AS1 and BACE1-AS as prognostic biomarkers in metastatic colorectal cancer

BACKGROUND

Despite the current diagnostic and therapeutic methods for colorectal cancer (CRC), patients are often diagnosed at advanced stages of colorectal cancer. Recently, numerous investigations have highlighted the role of lncRNAs in cancer development and progression. This study investigated less well-characterized genes in the colorectal cancer metastasis process.

MATERIALS AND METHODS

Genes expression profiles from CRC patients were downloaded from the TCGA database by the TCGAbiolinks R package. Differential gene expression analysis of miRNA, lncRNAs, and mRNAs was conducted for the M1 and M0 compared to control samples. Then, the DIANA lncbase3 tool was used to find M1-specific miRNA-LncRNA interactions. In addition, the expression of selected genes was evaluated by Real-time RT-PCR in forty-one CRC tissues.

RESULTS

Our analysis showed that the expression levels of 77 lncRNAs, 12 miRNAs, and 627 mRNA were significantly changed only in metastatic tumors. In experimental study, significant overexpression of LncRNAs LINC00839, LINC01006, BACE1-AS and G2E3-AS1 was confirmed in metastatic tumors. Also, ROC analysis showed that these lncRNAs, especially lncRNAs G2E3-AS1 and BACE1-AS, are good prognostic biomarkers for metastatic colorectal tumors.

CONCLUSION

We demonstrated that the lncRNAs G2E3-AS1 and BACE1-AS expression upregulated in CRC tissues can be good potential biomarkers for metastatic colorectal cancer.

Non-coding RNA biosensors for early detection of brain cancer

Brain cancer remains a formidable challenge with limited treatment options. Non-coding RNAs (ncRNAs) have emerged as promising biomarkers due to their dysregulation in tumorigenesis. This review explores the potential of biosensors for early detection of brain cancer by targeting ncRNAs. We discuss the classification and functions of ncRNAs, emphasizing their involvement in key cancer-related processes. Additionally, we delve into recent advancements in biosensor technology, focusing on their ability to accurately detect specific ncRNA biomarkers associated with brain cancer. Our findings underscore the potential of biosensors to revolutionize brain cancer diagnosis, enabling personalized medicine and improving patient outcomes. Future research should focus on refining biosensor technology and expanding their clinical application.

Epigenetic Targeting for Controlling Persistent Neurotropic Infections Caused by Borna Virus and HIV

Long-lasting persistence within infected cells is a major challenge for viral pathogens, as it necessitates an exact regulation of viral replication to reduce viral cytopathic effects. This is particularly challenging for viruses that persistently infect cells with limited renewal capabilities, such as neurons. Accordingly, neurotropic viruses have evolved various specific mechanisms to promote a long-lasting persistent infection in the host cells without inducing an exacerbated cytopathic effect. Borna disease virus (BDV) and Human immunodeficiency virus (HIV) are two neurotropic RNA viruses that, in contrast to other RNA viruses, can establish long-lasting intranuclear infections within the nervous system. These viruses interact with different cellular processes such as epigenetic modifications to develop a successful persistence infection. Studies show that cellular epigenetic mechanisms play a significant role in the pathogenesis of BDV and HIV and their neurological disorders. Hence, targeting these mechanisms by epigenetic modulator agents can be regarded as a novel therapeutic strategy to manage BDV- and HIV-associated neurological diseases. This review provides an overview of different epigenetic modulator compounds as a potential therapeutic target for controlling persistent neurotropic intranuclear infections caused by BDV and HIV.

Hearing modulation affects Alzheimer's disease progression linked to brain inflammation: a study in mouse models

BACKGROUND

Recent studies have identified hearing loss (HL) as a primary risk factor for Alzheimer's disease (AD) onset. However, the mechanisms linking HL to AD are not fully understood. This study explored the effects of drug-induced hearing loss (DIHL) on the expression of proteins associated with AD progression in mouse models.

METHODS

DIHL was induced in 5xFAD and Tg2576 mice aged 3 to 3.5 weeks using kanamycin (700 mg/kg, subcutaneous) and furosemide (600 mg/kg, intraperitoneal). The accumulation and expression of beta-amyloid (Aβ), ionized calcium-binding adaptor molecule 1 (Iba1), and glial fibrillary acidic protein (GFAP) were measured through immunohistochemistry and immunoblotting. Additionally, the expression of proteins involved in the mammalian target of rapamycin (mTOR) pathway, including downstream effectors p70 ribosomal S6 kinase (p70S6K) and S6, as well as proinflammatory cytokines, was analyzed.

RESULTS

Compared to control conditions, HL led to a significant increase in the accumulation of Aβ in the hippocampus and cortex. Elevated levels of neuroinflammatory markers, including Iba1 and GFAP, as well as proinflammatory cytokines such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α), were observed. Moreover, DIHL enhanced phosphorylation of mTOR, p70S6K, and S6, indicating activation of the mTOR pathway.

CONCLUSIONS

HL significantly increases Aβ accumulation in the brain. Furthermore, HL activates astrocytes and microglia, leading to increased neuroinflammation and thereby accelerating AD progression. These findings strongly suggest that HL contributes autonomously to neuroinflammation, highlighting the potential for early intervention in HL to reduce AD risk.

The interplay between epitranscriptomic RNA modifications and neurodegenerative disorders: Mechanistic insights and potential therapeutic strategies

Neurodegenerative disorders encompass a group of age-related conditions characterized by the gradual decline in both the structure and functionality of the central nervous system (CNS). RNA modifications, arising from the epitranscriptome or RNA-modifying protein mutations, have recently been observed to contribute significantly to neurodegenerative disorders. Specific modifications like N6-methyladenine (m6A), N1-methyladenine (m1A), 5-methylcytosine (m5C), pseudouridine and adenosine-to-inosine (A-to-I) play key roles, with their regulators serving as crucial therapeutic targets. These epitranscriptomic changes intricately control gene expression, influencing cellular functions and contributing to disease pathology. Dysregulation of RNA metabolism, affecting mRNA processing and noncoding RNA biogenesis, is a central factor in these diseases. This review underscores the complex relationship between RNA modifications and neurodegenerative disorders, emphasizing the influence of RNA modification and the epitranscriptome, exploring the function of RNA modification enzymes in neurodegenerative processes, investigating the functional consequences of RNA modifications within neurodegenerative pathways, and evaluating the potential therapeutic advancements derived from assessing the epitranscriptome.

Epigenetic Mechanisms of Aluminum-Induced Neurotoxicity and Alzheimer's Disease: A Focus on Non-Coding RNAs

Aluminum (Al) is known to induce neurotoxic effects, potentially contributing to Alzheimer's disease (AD) pathogenesis. Recent studies suggest that epigenetic modification may contribute to Al neurotoxicity, although the mechanisms are still debatable. Therefore, the objective of the present study was to summarize existing data on the involvement of epigenetic mechanisms in Al-induced neurotoxicity, especially AD-type pathology. Existing data demonstrate that Al exposure induces disruption in DNA methylation, histone modifications, and non-coding RNA expression in brains. Alterations in DNA methylation following Al exposure were shown to be mediated by changes in expression and activity of DNA methyltransferases (DNMTs) and ten-eleven translocation proteins (TETs). Al exposure was shown to reduce histone acetylation by up-regulating expression of histone deacetylases (HDACs) and impair histone methylation, ultimately contributing to down-regulation of brain-derived neurotrophic factor (BDNF) expression and activation of nuclear factor κB (NF-κB) signaling. Neurotoxic effects of Al exposure were also associated with aberrant expression of non-coding RNAs, especially microRNAs (miR). Al-induced patterns of miR expression were involved in development of AD-type pathology by increasing amyloid β (Aβ) production through up-regulation of Aβ precursor protein (APP) and β secretase (BACE1) expression (down-regulation of miR-29a/b, miR-101, miR-124, and Let-7c expression), increasing in neuroinflammation through NF-κB signaling (up-regulation of miR-9, miR-125b, miR-128, and 146a), as well as modulating other signaling pathways. Furthermore, reduced global DNA methylation, altered histone modification, and aberrant miRNA expression were associated with cognitive decline in Al-exposed subjects. However, further studies are required to evaluate the contribution of epigenetic mechanisms to Al-induced neurotoxicity and/or AD development.

Astrocytes in Amyloid Generation and Alcohol Metabolism: Implications of Alcohol Use in Neurological Disorder(s)

As per the National Survey on Drug Use and Health, 10.5% of Americans aged 12 years and older are suffering from alcohol use disorder, with a wide range of neurological disorders. Alcohol-mediated neurological disorders can be linked to Alzheimer's-like pathology, which has not been well studied. We hypothesize that alcohol exposure can induce astrocytic amyloidosis, which can be corroborated by the neurological disorders observed in alcohol use disorder. In this study, we demonstrated that the exposure of astrocytes to ethanol resulted in an increase in Alzheimer's disease markers-the amyloid precursor protein, Aβ1-42, and the β-site-cleaving enzyme; an oxidative stress marker-4HNE; proinflammatory cytokines-TNF-α, IL1β, and IL6; lncRNA BACE1-AS; and alcohol-metabolizing enzymes-alcohol dehydrogenase, aldehyde dehydrogenase-2, and cytochrome P450 2E1. A gene-silencing approach confirmed the regulatory role of lncRNA BACE1-AS in amyloid generation, alcohol metabolism, and neuroinflammation. This report is the first to suggest the involvement of lncRNA BACE1-AS in alcohol-induced astrocytic amyloid generation and alcohol metabolism. These findings will aid in developing therapies targeting astrocyte-mediated neurological disorders and cognitive deficits in alcohol users.

Non-Coding RNAs in HIV Infection, NeuroHIV, and Related Comorbidities

NeuroHIV affects approximately 30-60% of people living with HIV-1 (PLWH) and is characterized by varying degrees of cognitive impairments, presenting a multifaceted challenge, the underlying cause of which is chronic, low-level neuroinflammation. Such smoldering neuroinflammation is likely an outcome of lifelong reliance on antiretrovirals coupled with residual virus replication in the brains of PLWH. Despite advancements in antiretroviral therapeutics, our understanding of the molecular mechanism(s) driving inflammatory processes in the brain remains limited. Recent times have seen the emergence of non-coding RNAs (ncRNAs) as critical regulators of gene expression, underlying the neuroinflammatory processes in HIV infection, NeuroHIV, and their associated comorbidities. This review explores the role of various classes of ncRNAs and their regulatory functions implicated in HIV infection, neuropathogenesis, and related conditions. The dysregulated expression of ncRNAs is known to exacerbate the neuroinflammatory responses, thus contributing to neurocognitive impairments in PLWH. This review also discusses the diagnostic and therapeutic potential of ncRNAs in HIV infection and its comorbidities, suggesting their utility as non-invasive biomarkers and targets for modulating neuroinflammatory pathways. Understanding these regulatory roles could pave the way for novel diagnostic strategies and therapeutic interventions in the context of HIV and its comorbidities.

Role of long non-coding RNAs in the pathophysiology of Alzheimer's disease and other dementias

Dementia is the term used to describe a group of cognitive disorders characterized by a decline in memory, thinking, and reasoning abilities that interfere with daily life activities. Examples of dementia include Alzheimer's Disease (AD), Frontotemporal dementia (FTD), Amyotrophic lateral sclerosis (ALS), Vascular dementia (VaD) and Progressive supranuclear palsy (PSP). AD is the most common form of dementia. The hallmark pathology of AD includes formation of β-amyloid (Aβ) oligomers and tau hyperphosphorylation in the brain, which induces neuroinflammation, oxidative stress, synaptic dysfunction, and neuronal apoptosis. Emerging studies have associated long non-coding RNAs (lncRNAs) with the pathogenesis and progression of the neurodegenerative diseases. LncRNAs are defined as RNAs longer than 200 nucleotides that lack the ability to encode functional proteins. LncRNAs play crucial roles in numerous biological functions for their ability to interact with different molecules, such as proteins and microRNAs, and subsequently regulate the expression of their target genes at transcriptional and post-transcriptional levels. In this narrative review, we report the function and mechanisms of action of lncRNAs found to be deregulated in different types of dementia, with the focus on AD. Finally, we discuss the emerging role of lncRNAs as biomarkers of dementias.

Alzheimer's disease and microorganisms: the non-coding RNAs crosstalk

Alzheimer's disease (AD) is a complex, multifactorial disorder, influenced by a multitude of variables ranging from genetic factors, age, and head injuries to vascular diseases, infections, and various other environmental and demographic determinants. Among the environmental factors, the role of the microbiome in the genesis of neurodegenerative disorders (NDs) is gaining increased recognition. This paradigm shift is substantiated by an extensive body of scientific literature, which underscores the significant contributions of microorganisms, encompassing viruses and gut-derived bacteria, to the pathogenesis of AD. The mechanism by which microbial infection exerts its influence on AD hinges primarily on inflammation. Neuroinflammation, activated in response to microbial infections, acts as a defense mechanism for the brain but can inadvertently lead to unexpected neuropathological perturbations, ultimately contributing to NDs. Given the ongoing uncertainty surrounding the genetic factors underpinning ND, comprehensive investigations into environmental factors, particularly the microbiome and viral agents, are imperative. Recent advances in neuroscientific research have unveiled the pivotal role of non-coding RNAs (ncRNAs) in orchestrating various pathways integral to neurodegenerative pathologies. While the upstream regulators governing the pathological manifestations of microorganisms remain elusive, an in-depth exploration of the nuanced role of ncRNAs holds promise for the development of prospective therapeutic interventions. This review aims to elucidate the pivotal role of ncRNAs as master modulators in the realm of neurodegenerative conditions, with a specific focus on Alzheimer's disease.

The role of microRNAs in the pathophysiology of human central nervous system: A focus on neurodegenerative diseases

microRNAs (miRNAs) are suggested to play substantial roles in regulating the development and various physiologic functions of the central nervous system (CNS). These include neurogenesis, cell fate and differentiation, morphogenesis, formation of dendrites, and targeting non-neural mRNAs. Notably, deregulation of an increasing number of miRNAs is associated with several neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis and CNS tumors. They are particularly known to affect the amyloid β (Aβ) cleavage and accumulation, tau protein homeostasis, and expression of alpha-synuclein (α-syn), Parkin, PINK1, and brain-derived neurotrophic factor (BDNF) that play pivotal roles in the pathogenesis of neurodegenerative diseases. These include miR-16, miR-17-5p, miR-20a, miR-106a, miR-106b, miR-15a, miR-15b, miR-103, miR-107, miR-298, miR-328, miR-195, miR-485, and miR-29. In CNS tumors, several miRNAs, including miR-31, miR-16, and miR-21 have been identified to modulate tumorigenesis through impacting tumor invasion and apoptosis. In this review article, we have a look at the recent advances on our knowledge about the role of miRNAs in human brain development and functions, neurodegenerative diseases, and their clinical potentials.

microRNA-184 in the landscape of human malignancies: a review to roles and clinical significance

MicroRNAs (miRNAs) are a class of non-coding RNAs (ncRNAs) with a short length of 19-22 nucleotides. miRNAs are posttranscriptional regulators of gene expression involved in various biological processes like cell growth, apoptosis, and angiogenesis. miR-184 is a well-studied miRNA, for which most studies report its downregulation in cancer cells and tissues and experiments support its role as a tumor suppressor inhibiting malignant biological behaviors of cancer cells in vitro and in vivo. To exert its functions, miR-184 affects some signaling pathways involved in tumorigenesis like Wnt and β-catenin, and AKT/mTORC1 pathway, oncogenic factors (e.g., c-Myc) or apoptotic proteins, such as Bcl-2. Interestingly, clinical investigations have shown miR-184 with good performance as a prognostic/diagnostic biomarker for various cancers. Additionally, exogenous miR-184 in cell and xenograft animal studies suggest it as a therapeutic anticancer target. In this review, we outline the studies that evaluated the roles of miR-184 in tumorigenesis as well as its clinical significance.

Exploration of the Noncoding Genome for Human-Specific Therapeutic Targets-Recent Insights at Molecular and Cellular Level

While it is well known that 98-99% of the human genome does not encode proteins, but are nevertheless transcriptionally active and give rise to a broad spectrum of noncoding RNAs [ncRNAs] with complex regulatory and structural functions, specific functions have so far been assigned to only a tiny fraction of all known transcripts. On the other hand, the striking observation of an overwhelmingly growing fraction of ncRNAs, in contrast to an only modest increase in the number of protein-coding genes, during evolution from simple organisms to humans, strongly suggests critical but so far essentially unexplored roles of the noncoding genome for human health and disease pathogenesis. Research into the vast realm of the noncoding genome during the past decades thus lead to a profoundly enhanced appreciation of the multi-level complexity of the human genome. Here, we address a few of the many huge remaining knowledge gaps and consider some newly emerging questions and concepts of research. We attempt to provide an up-to-date assessment of recent insights obtained by molecular and cell biological methods, and by the application of systems biology approaches. Specifically, we discuss current data regarding two topics of high current interest: (1) By which mechanisms could evolutionary recent ncRNAs with critical regulatory functions in a broad spectrum of cell types (neural, immune, cardiovascular) constitute novel therapeutic targets in human diseases? (2) Since noncoding genome evolution is causally linked to brain evolution, and given the profound interactions between brain and immune system, could human-specific brain-expressed ncRNAs play a direct or indirect (immune-mediated) role in human diseases? Synergistic with remarkable recent progress regarding delivery, efficacy, and safety of nucleic acid-based therapies, the ongoing large-scale exploration of the noncoding genome for human-specific therapeutic targets is encouraging to proceed with the development and clinical evaluation of novel therapeutic pathways suggested by these research fields.

microRNA-382 as a tumor suppressor? Roles in tumorigenesis and clinical significance

MicroRNAs (miRNAs) are small single-stranded RNAs belonging to a class of non-coding RNAs with an average length of 18-22 nucleotides. Although not able to encode any protein, miRNAs are vastly studied and found to play role in various human physiologic as well as pathological conditions. A huge number of miRNAs have been identified in human cells whose expression is straightly regulated with crucial biological functions, while this number is constantly increasing. miRNAs are particularly studied in cancers, where they either can act with oncogenic function (oncomiRs) or tumor-suppressors role (referred as tumor-suppressor/oncorepressor miRNAs). miR-382 is a well-studied miRNA, which is revealed to play regulatory roles in physiological processes like osteogenic differentiation, hematopoietic stem cell differentiation and normal hematopoiesis, and liver progenitor cell differentiation. Notably, miR-382 deregulation is reported in pathologic conditions, such as renal fibrosis, muscular dystrophies, Rett syndrome, epidural fibrosis, atrial fibrillation, amelogenesis imperfecta, oxidative stress, human immunodeficiency virus (HIV) replication, and various types of cancers. The majority of oncogenesis studies have claimed miR-382 downregulation in cancers and suppressor impact on malignant phenotype of cancer cells in vitro and in vivo, while a few studies suggest opposite findings. Given the putative role of this miRNA in regulation of oncogenesis, assessment of miR-382 expression is suggested in a several clinical investigations as a prognostic/diagnostic biomarker for cancer patients. In this review, we have an overview to recent studies evaluated the role of miR-382 in oncogenesis as well as its clinical potential.

Long non-coding RNAs BACE1-AS and BC200 in multiple sclerosis and their relation to cognitive function: A gene expression analysis

Cognitive impairment is a common and debilitating feature of multiple sclerosis (MS), and the dysregulation of synaptic plasticity is one of its direct causes. Long non-coding RNAs (lncRNAs) have been shown to play a role in synaptic plasticity, but their role in cognitive impairment in MS has not been fully explored. In this study, using quantitative real-time PCR, we examined the relative expression of two specific lncRNAs, BACE1-AS and BC200, in the serum of two cohorts of MS patients with and without cognitive impairment. Both lncRNAs were overexpressed in both cognitively impaired and non-cognitively impaired MS patients, with consistently higher levels in the cohort with cognitive impairment. We also found a strong positive correlation between the expression levels of these two lncRNAs. Notably, BACE1-AS was consistently higher in the remitting cases of both relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS) groups than in the respective relapse cases of the same subtype, with the SPMS-Remitting group of cognitively impaired MS patients showing the highest expression of BACE1-AS among all MS groups. Additionally, we observed that the primary progressive MS (PPMS) group had the highest expression of BC200 in both cohorts of MS. Furthermore, we developed a model called Neuro_Lnc-2, which showed better diagnostic performance than either BACE1-AS or BC200 alone in predicting MS. Our findings suggest that these two lncRNAs may have a significant impact on the pathogenesis of the progressive types of MS and on the cognitive function of the patients. Future research is required to confirm these findings.

The role of microRNA-185 in the pathogenesis of human diseases: A focus on cancer

MicroRNAs (miRNAs) are a widely-studied class of non-coding RNAs characterized by their short length (18-25 nucleotides). The precise functions of miRNAs are not well-elucidated; however, an increasing number of studies suggest their involvement in various physiologic processes and deregulation in pathologic conditions. miRNA-185 (miR-185) is among the mostly-studied miRNAs in human diseases, which is found to play putative roles in conditions like metabolic disorders, asthma, frailty, schizophrenia, and hepatitis. Notably, many cancer studies report the downregulation of miR-185 in cell lines, tumor tissues, and plasma specimens of patients, while it demonstrates a suppressing role on the malignant properties of cancer cells in vitro and in vivo. Accordingly, miR-185 can be considered a tumor suppressor miRNA in human malignancies, while a few studies also report inconsistent findings. Being suggested as a prognostic/diagnostic biomarker, mi-185 is also found to offer clinical potentials, particularly for early diagnosis and prediction of the prognosis of cancer patients. In this review, we have outlined the studies that have evaluated the functions and clinical significance of miR-185 in different human diseases with a particular focus on cancer.

Targeting Non-Coding RNA for CNS Injuries: Regulation of Blood-Brain Barrier Functions

Central nervous system (CNS) injuries are the most common cause of death and disability around the world. The blood-brain barrier (BBB) is located at the interface between the CNS and the surrounding environment, which protects the CNS from exogenous molecules, harmful agents or microorganisms in the blood. The disruption of BBB is a common feature of CNS injuries and participates in the pathological processes of secondary brain damage. Recently, a growing number of studies have indicated that non-coding RNAs (ncRNAs) play an important role in brain development and are involved in CNS injuries. In this review, we summarize the mechanisms of BBB breakdown after CNS injuries. We also discuss the effects of ncRNAs including long noncoding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs) on BBB damage in CNS injuries such as ischemic stroke, traumatic brain injury (TBI), intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH). In addition, we clarify the pharmacotherapies that could regulate BBB function via ncRNAs in CNS injuries, as well as the challenges and perspectives of ncRNAs on modulation of BBB function. Hence, on the basis of these effects, ncRNAs may be developed as therapeutic agents to protect the BBB for CNS injury patients.

Recent insights into the roles of circular RNAs in human brain development and neurologic diseases

Circular RNAs (circRNAs) are a novel class of non-coding RNAs. They are single-stranded RNA transcripts characterized with a closed loop structure making them resistant to degrading enzymes. Recently, circRNAs have been suggested with regulatory roles in gene expression involved in controlling various biological processes. Notably, they have demonstrated abundance, dynamic expression, back-splicing events, and spatiotemporally regulation in the human brain. Accordingly, they are expected to be involved in brain functions and related diseases. Studies in animals and human brain have revealed differential expression of circRNAs in brain compartments. Interestingly, contributing roles of circRNAs in the regulation of central nervous system (CNS) development have been demonstrated in a number of studies. It has been proposed that circRNAs play role in substantial neurological functions like neurotransmitter-associated tasks, neural cells maturation, and functions of synapses. Furthermore, 3 main pathways have been identified in association with circRNAs's host genes including axon guidance, Wnt signaling, and transforming growth factor beta (TGF-β) signaling pathways, which are known to be involved in substantial functions like migration and differentiation of neurons and specification of axons, and thus play role in brain development. In this review, we have an overview to the biogenesis, biological functions of circRNAs, and particularly their roles in human brain development and the pathogenesis of neurodegenerative diseases including Alzheimer's diseases, multiple sclerosis, Parkinson's disease and brain tumors.

Depression Pathophysiology: Astrocyte Mitochondrial Melatonergic Pathway as Crucial Hub

Major depressive disorder (MDD) is widely accepted as having a heterogenous pathophysiology involving a complex mixture of systemic and CNS processes. A developmental etiology coupled to genetic and epigenetic risk factors as well as lifestyle and social process influences add further to the complexity. Consequently, antidepressant treatment is generally regarded as open to improvement, undoubtedly as a consequence of inappropriately targeted pathophysiological processes. This article reviews the diverse array of pathophysiological processes linked to MDD, and integrates these within a perspective that emphasizes alterations in mitochondrial function, both centrally and systemically. It is proposed that the long-standing association of MDD with suppressed serotonin availability is reflective of the role of serotonin as a precursor for the mitochondrial melatonergic pathway. Astrocytes, and the astrocyte mitochondrial melatonergic pathway, are highlighted as crucial hubs in the integration of the wide array of biological underpinnings of MDD, including gut dysbiosis and permeability, as well as developmental and social stressors, which can act to suppress the capacity of mitochondria to upregulate the melatonergic pathway, with consequences for oxidant-induced changes in patterned microRNAs and subsequent patterned gene responses. This is placed within a development context, including how social processes, such as discrimination, can physiologically regulate a susceptibility to MDD. Future research directions and treatment implications are derived from this.

Long Non-Coding RNAs, Extracellular Vesicles and Inflammation in Alzheimer's Disease

Alzheimer's Disease (AD) has currently no effective treatment; however, preventive measures have the potential to reduce AD risk. Thus, accurate and early prediction of risk is an important strategy to alleviate the AD burden. Neuroinflammation is a major factor prompting the onset of the disease. Inflammation exerts its toxic effect via multiple mechanisms. Amongst others, it is affecting gene expression via modulation of non-coding RNAs (ncRNAs), such as miRNAs. Recent evidence supports that inflammation can also affect long non-coding RNA (lncRNA) expression. While the association between miRNAs and inflammation in AD has been studied, the role of lncRNAs in neurodegenerative diseases has been less explored. In this review, we focus on lncRNAs and inflammation in the context of AD. Furthermore, since plasma-isolated extracellular vesicles (EVs) are increasingly recognized as an effective monitoring strategy for brain pathologies, we have focused on the studies reporting dysregulated lncRNAs in EVs isolated from AD patients and controls. The revised literature shows a positive association between pro-inflammatory lncRNAs and AD. However, the reports evaluating lncRNA alterations in EVs isolated from the plasma of patients and controls, although still limited, confirm the value of specific lncRNAs associated with AD as reliable biomarkers. This is an emerging field that will open new avenues to improve risk prediction and patient stratification, and may lead to the discovery of potential novel therapeutic targets for AD.

Long-noncoding RNAs as epigenetic regulators in neurodegenerative diseases

The growing and rapid development of high-throughput sequencing technologies have allowed a greater understanding of the mechanisms underlying gene expression regulation. Editing the epigenome and epitranscriptome directs the fate of the transcript influencing the functional outcome of each mRNA. In this context, non-coding RNAs play a decisive role in addressing the expression regulation at the gene and chromosomal levels. Long-noncoding RNAs, consisting of more than 200 nucleotides, have been shown to act as epigenetic regulators in several key molecular processes involving neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and Huntington's disease. Long-noncoding RNAs are abundantly expressed in the central nervous system, suggesting that their deregulation could trigger neuronal degeneration through RNA modifications. The evaluation of their diagnostic significance and therapeutic potential could lead to new treatments for these diseases for which there is no cure.