LncRNA-UCA1 inhibits the astrocyte activation in the temporal lobe epilepsy via regulating the JAK/STAT signaling pathway

Emerging roles of long non-coding RNAs in human epilepsy

Genome-scale biological studies conducted in the post-genomic era have revealed that two-thirds of human genes do not encode proteins. Most functional non-coding RNA transcripts in humans are products of long non-coding RNA (lncRNA) genes, an abundant but still poorly understood class of human genes. As a result of their fundamental and multitasking regulatory roles, lncRNAs are associated with a wide range of human diseases, including neurological disorders. Approximately 40% of lncRNAs are specifically expressed in the brain, and many of them exhibit distinct spatiotemporal patterns of expression. Comparative genomics approaches have determined that 65%-75% of human lncRNA genes are primate-specific and hence can be posited as a contributing potential cause of the higher-order complexity of primates, including human, brains relative to those of other mammals. Although lncRNAs present important mechanistic examples of epileptogenic functions, the human/primate specificity of lncRNAs questions their relevance in rodent models. Here, we present an in-depth review that supports the contention that human lncRNAs are direct contributors to the etiology and pathogenesis of human epilepsy, as a means to accelerate the integration of lncRNAs into clinical practice as potential diagnostic biomarkers and therapeutic targets. Meta-analytically, the major finding of our review is the commonality of lncRNAs in epilepsy and cancer pathogenesis through mitogen-activated protein kinase (MAPK)-related pathways. In addition, neuroinflammation may be a relevant part of the common pathophysiology of cancer and epilepsy. LncRNAs affect neuroinflammation-related signaling pathways such as nuclear factor kappa- light- chain- enhancer of activated B cells (NF-κB), Notch, and phosphatidylinositol 3- kinase/ protein kinase B (Akt) (PI3K/AKT), with the NF-κB pathway being the most common. Besides the controversy over lncRNA research in non-primate models, whether neuroinflammation is triggered by injury and/or central nervous system (CNS) toxicity during epilepsy modeling in animals or is a direct consequence of epilepsy pathophysiology needs to be considered meticulously in future studies.

The regulatory relationship between transcription factor STAT3 and noncoding RNA

Signal transducer and activator of transcription 3 (STAT3), as a key node in numerous carcinogenic signaling pathways, is activated in various tumor tissues and plays important roles in tumor formation, metastasis, and drug resistance. STAT3 is considered a potential subtarget for tumor therapy. Noncoding RNA (ncRNA) is a special type of RNA transcript. Transforming from "junk" transcripts into key molecules involved in cell apoptosis, growth, and functional regulation, ncRNA has been proven to be closely related to various epithelial-mesenchymal transition and drug resistance processes in tumor cells over the past few decades. Research on the relationship between transcription factor STAT3 and ncRNAs has attracted increased attention. To date, existing reviews have mainly focused on the regulation by ncRNAs on the transcription factor STAT3; there has been no review of the regulation by STAT3 on ncRNAs. However, understanding the regulation of ncRNAs by STAT3 and its mechanism is important to comprehensively understand the mutual regulatory relationship between STAT3 and ncRNAs. Therefore, in this review, we summarize the regulation by transcription factor STAT3 on long noncoding RNA, microRNA, and circular RNA and its possible mechanisms. In addition, we provide an update on research progress on the regulation of STAT3 by ncRNAs. This will provide a new perspective to comprehensively understand the regulatory relationship between transcription factor STAT3 and ncRNAs, as well as targeting STAT3 or ncRNAs to treat diseases such as tumors.

Profound seizure suppression and disease modification by targeting JAK1, a key driver of a pro-epileptogenic gene network

Epilepsy is the 4th most prevalent neurological disorder with over 50 million cases worldwide. While a number of drugs exist to suppress seizures, approximately 1/3 of patients remain drug resistant, and no current treatments are disease modifying. Using network and systems-based approaches, we find that the histone methylase EZH2 suppresses epileptogenesis and slows disease progression, via repression of JAK1 and STAT3 signaling in hippocampal neurons. Pharmacological inhibition of JAK1 with the orally available, FDA-approved drug CP690550 (Tofacitinib) profoundly suppresses behavioral and electrographic seizures after the onset of epilepsy across preclinical rodent models of acquired epilepsy. This seizure suppression persists for weeks after drug withdrawal. Identification of an endogenous protective response to status epilepticus in the form of EZH2 induction has highlighted a critical role for the JAK1 kinase and STAT3 in both the initiation and propagation of epilepsy across preclinical rodent models and human disease. Overall, we find that STAT3 is transiently activated after insult, reactivates with spontaneous seizures, and remains targetable for disease modification in chronic epilepsy.

Regulation of Glial Function by Noncoding RNA in Central Nervous System Disease

Non-coding RNAs (ncRNAs) are a class of functional RNAs that play critical roles in different diseases. NcRNAs include microRNAs, long ncRNAs, and circular RNAs. They are highly expressed in the brain and are involved in the regulation of physiological and pathophysiological processes of central nervous system (CNS) diseases. Mounting evidence indicates that ncRNAs play key roles in CNS diseases. Further elucidating the mechanisms of ncRNA underlying the process of regulating glial function that may lead to the identification of novel therapeutic targets for CNS diseases.

The regulatory function of lncRNA and constructed network in epilepsy

BACKGROUND

Epilepsy is a neurological disease characterized by neural network dysfunction. Although most reports indicate that the pathological process of epilepsy is related to inflammation, synaptic plasticity, cell apoptosis, and ion channel dysfunction, the underlying molecular mechanisms of epilepsy are not fully understood.

METHODS

This review summarizes the latest literature on the roles and characteristics of long noncoding RNAs (lncRNAs) in the pathogenesis of epilepsy.

RESULTS

lncRNAs are a class of long transcripts without protein-coding functions that perform important regulatory functions in various biological processes. lncRNAs are involved in the regulation of the pathological process of epilepsy and are abnormally expressed in both patients and animal models. This review provides an overview of research progress in epilepsy, the multifunctional features of lncRNAs, the lncRNA expression pattern related to epileptogenesis and status epilepticus, and the potential mechanisms for the two interactions contributing to epileptogenesis and progression.

CONCLUSION

lncRNAs can serve as new diagnostic markers and therapeutic targets for epilepsy in the future.

Role of lncRNAs and circRNAs in epilepsy

Epilepsy is a chronic disorder of with a high prevalence and extensive health burden in almost all age groups of the population. This condition is resulted from disturbance in the balance between excitatory and inhibitory factors in the brain. Genetic elements that affect synaptic connectivity, receptors functions or ion channels have been shown to predispose individuals to the epilepsy. More recently, a body of evidence points to the role of non-coding part of the transcriptome in the pathology of epilepsy. Expression levels of NEAT1, H19, PVT1, ILF3-AS1, GAS5, ZFAS1, UCA1, MALAT1 and SNHG1 have been changed in epileptic patients or animal models of epilepsy. Moreover, circ_ANKMY2, circRNA-0067835 and circHivep2 are among circRNAs which are involved in the pathogenesis of epilepsy. Although the mechanistical impact of these transcripts in the pathogenesis of epilepsy has not been fully explored, disturbances in neuron plasticity, apoptosis or differentiation might be implicated in this process. Expression levels of lncRNAs can be used for discrimination of epileptic patients from normal controls or refractory patients from non-refractory ones. JAK/STAT, Wnt, PI3K/AKT and NF-κB signaling pathways are among the regulated pathways by lncRNAs in the context of epilepsy. In the present review, we summarize the role of lncRNAs and circRNAs in the pathogenesis of epilepsy.

Long non-coding RNAs: Potential therapeutic targets for epilepsy

Epilepsy is a common and disastrous neurological disorder characterized by abnormal firing of neurons in the brain, affecting about 70 million people worldwide. Long non-coding RNAs (LncRNAs) are a class of RNAs longer than 200 nucleotides without the capacity of protein coding, but they participate in a wide variety of pathophysiological processes. Alternated abundance and diversity of LncRNAs have been found in epilepsy patients and animal or cell models, suggesting a potential role of LncRNAs in epileptogenesis. This review will introduce the structure and function of LncRNAs, summarize the role of LncRNAs in the pathogenesis of epilepsy, especially its linkage with neuroinflammation, apoptosis, and transmitter balance, which will throw light on the molecular mechanism of epileptogenesis, and accelerate the clinical implementation of LncRNAs as a potential therapeutic target for treatment of epilepsy.

Protective role of ethyl pyruvate in spinal cord injury by inhibiting the high mobility group box-1/toll-like receptor4/nuclear factor-kappa B signaling pathway

Spinal cord injury (SCI) is a high incident rate of central nervous system disease that usually causes paralysis below the injured level. The occurrence of chronic inflammation with the axonal regeneration difficulties are the underlying barriers for the recovery of SCI patients. Current studies have paid attention to controlling the instigative and developmental process of neuro-inflammation. Ethyl pyruvate, as a derivative of pyruvate, has strong anti-inflammatory and neuroprotective functions. Herein, we reviewed the recent studies of ethyl pyruvate and high mobility group box-1 (HMGB1). We think HMGB1 that is one of the main nuclear protein mediators to cause an inflammatory response. This protein induces astrocytic activation, and promotes glial scar formation. Interestingly, ethyl pyruvate has potent inhibitory effects on HMGB1 protein, as it inhibits chronic inflammatory response by modulating the HMGB1/TLR4/NF-κB signaling pathway. This paper discusses the potential mechanism of ethyl pyruvate in inhibiting chronic inflammation after SCI. Ethyl pyruvate can be a prospective therapeutic agent for SCI.

LncRNA RMRP Contributes to the Development and Progression of Spinal Cord Injury by Regulating miR-766-5p/FAM83A Axis

Spinal cord injury (SCI) is known as a central nervous system disorder. Previous studies suggested that long-non-coding RNA RMRP (LncRNA RMRP) was abnormally expressed in SCI, but the potential underlying mechanism remains to be further explored. To explore the regulatory roles of LncRNA RMRP/miR-766-5p/FAM83A axis in SCI. Spinal T9 hemisection was performed on healthy adult male Sprague Dawley (SD) rats to establish the SCI rat models. The expressions of LncRNA RMRP in spinal cord of rats in different groups were examined by RT-qPCR. Moreover, AGE1.HN and PC12 cells were treated with hypoxic condition, and expression of LncRNA RMRP was examined by RT-qPCR methods. Furthermore, hypoxic PC12 cells were transfected with LncRNA RMRP OE, and the cell viability, proliferation, and apoptosis were examined. Next, the direct targeting relationship between LncRNA RMRP and miR-766-5p, as well as miR-766-5p and FAM83A, was confirmed by dual-luciferase reporter and RNA pull-down assays. Finally, the effects of LncRNA RMRP/miR-766-5p/FAM83A axis on cell viability, proliferation, and apoptosis were examined. LncRNA RMRP was downregulated in SCI rats and over-expression of LncRNA RMRP alleviated the SCI condition. LncRNA RMRP over-expression increased the viability and proliferation, and inhibited the apoptosis of hypoxic PC12 cells in vitro. miR-766-5p was confirmed as a target of LncRNA RMRP, and FAM83A was confirmed as a target of miR-766-5p. LncRNA RMRP could regulate the proliferation and apoptosis of hypoxic PC12 cells via regulating miR-766-5p/FAM83A axis in vitro. LncRNA RMRP may contribute to the pathogenesis of SCI via regulating miR-766-5p/FAM83A axis.

Non-Coding RNAs: New Biomarkers and Therapeutic Targets for Temporal Lobe Epilepsy

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy; it is considered a network disorder associated with structural changes. Incomplete knowledge of the pathological changes in TLE complicates a therapeutic approach; indeed, 30 to 50% of patients with TLE are refractory to drug treatment. Non-coding RNAs (ncRNAs), acting as epigenetic factors, participate in the regulation of the pathophysiological processes of epilepsy and are dysregulated during epileptogenesis. Abnormal expression of ncRNA is observed in patients with epilepsy and in animal models of epilepsy. Furthermore, ncRNAs could also be used as biomarkers for the diagnosis and prognosis of treatment response in epilepsy. In summary, ncRNAs can represent important mechanisms and targets for the modulation of brain excitability and can provide information on pathomechanisms, biomarkers and novel therapies for epilepsy. In this review, we summarize the latest research advances concerning mainly molecular mechanisms, regulated by ncRNA, such as synaptic plasticity, inflammation and apoptosis, already associated with the pathogenesis of TLE. Moreover, we discuss the role of ncRNAs, such as microRNAs, long non-coding RNAs and circular RNAs, in the pathophysiology of epilepsy, highlighting their use as potential biomarkers for future therapeutic approaches.

Long Non-coding RNAs and Circular RNAs: Insights Into Microglia and Astrocyte Mediated Neurological Diseases

Microglia and astrocytes maintain tissue homeostasis in the nervous system. Both microglia and astrocytes have pro-inflammatory phenotype and anti-inflammatory phenotype. Activated microglia and activated astrocytes can contribute to several neurological diseases. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), two groups of non-coding RNAs (ncRNAs), can function as competing endogenous RNAs (ceRNAs) to impair the microRNA (miRNA) inhibition on targeted messenger RNAs (mRNAs). LncRNAs and circRNAs are involved in various neurological disorders. In this review, we summarized that lncRNAs and circRNAs participate in microglia dysfunction, astrocyte dysfunction, neuron damage, and inflammation. Thereby, lncRNAs and circRNAs can positively or negatively regulate neurological diseases, including spinal cord injury (SCI), traumatic brain injury (TBI), ischemia-reperfusion injury (IRI), stroke, neuropathic pain, epilepsy, Parkinson’s disease (PD), multiple sclerosis (MS), and Alzheimer’s disease (AD). Besides, we also found a lncRNA/circRNA-miRNA-mRNA regulatory network in microglia and astrocyte mediated neurological diseases. Through this review, we hope to cast light on the regulatory mechanisms of lncRNAs and circRNAs in microglia and astrocyte mediated neurological diseases and provide new insights for neurological disease treatment.

The role of the TNFα-mediated astrocyte signaling pathway in epilepsy

Epilepsy is a common disease  in the central nervous system. There is growing evidence that epilepsy is associated with glial cells, including astrocytes. Tumor necrosis factor α (TNFα) is a “master regulator” of proinflammatory cytokine production and is secreted by microglia and astrocytes. TNFα secreted by microglia can activate astrocytes. Additionally, TNFα can regulate neuron activity and induce epilepsy by increasing the glutamate release, reducing the expression of γ-aminobutyric acid, inducing neuroinflammation and affecting the synaptic function in astrocytes. This review summarizes the signaling pathways and receptors of TNFα acting on astrocytes that are related to epilepsy and provides insights into the potential therapeutic strategies of epilepsy for clinical practice.

Regulatory role of long non-coding RNA UCA1 in signaling pathways and its clinical applications

Long non-coding RNA metastasis-associated urothelial carcinoma associated 1 (UCA1) plays a pivotal role in various human diseases. Its gene expression is regulated by several factors, including transcription factors, chromatin remodeling and epigenetic modification. UCA1 is involved in the regulation of the PI3K/AKT, Wnt/β-catenin, MAPK, NF-κB and JAK/STAT signaling pathways, affecting a series of cellular biological functions, such as cell proliferation, apoptosis, migration, invasion and tumor drug resistance. Furthermore, UCA1 is used as a novel potential biomarker for disease diagnosis and prognosis, as well as a target for clinical gene therapy. The present review systematically summarizes and elucidates the mechanisms of upstream transcriptional regulation of UCA1, the regulatory role of UCA1 in multiple signaling pathways in the occurrence and development of several diseases, and its potential applications in clinical treatment.

Toward Regulatory Effects of Curcumin on Transforming Growth Factor-Beta Across Different Diseases: A Review

Immune response, proliferation, migration and angiogenesis are juts a few of cellular events that are regulated by transforming growth factor-β (TGF-β) in cells. A number of studies have documented that TGF-β undergoes abnormal expression in different diseases, e.g., diabetes, cancer, fibrosis, asthma, arthritis, among others. This has led to great fascination into this signaling pathway and developing agents with modulatory impact on TGF-β. Curcumin, a natural-based compound, is obtained from rhizome and roots of turmeric plant. It has a number of pharmacological activities including antioxidant, anti-inflammatory, anti-tumor, anti-diabetes and so on. Noteworthy, it has been demonstrated that curcumin affects different molecular signaling pathways such as Wnt/β-catenin, Nrf2, AMPK, mitogen-activated protein kinase and so on. In the present review, we evaluate the potential of curcumin in regulation of TGF-β signaling pathway to corelate it with therapeutic impacts of curcumin. By modulation of TGF-β (both upregulation and down-regulation), curcumin ameliorates fibrosis, neurological disorders, liver disease, diabetes and asthma. Besides, curcumin targets TGF-β signaling pathway which is capable of suppressing proliferation of tumor cells and invading cancer cells.