Long noncoding RNA BDNF-AS regulates ketamine-induced neurotoxicity in neural stem cell derived neurons

Hidden regulators: the emerging roles of lncRNAs in brain development and disease

Long non-coding RNAs (lncRNAs) have emerged as critical players in brain development and disease. These non-coding transcripts, which once considered as "transcriptional junk," are now known for their regulatory roles in gene expression. In brain development, lncRNAs participate in many processes, including neurogenesis, neuronal differentiation, and synaptogenesis. They employ their effect through a wide variety of transcriptional and post-transcriptional regulatory mechanisms through interactions with chromatin modifiers, transcription factors, and other regulatory molecules. Dysregulation of lncRNAs has been associated with certain brain diseases, including Alzheimer's disease, Parkinson's disease, cancer, and neurodevelopmental disorders. Altered expression and function of specific lncRNAs have been implicated with disrupted neuronal connectivity, impaired synaptic plasticity, and aberrant gene expression pattern, highlighting the functional importance of this subclass of brain-enriched RNAs. Moreover, lncRNAs have been identified as potential biomarkers and therapeutic targets for neurological diseases. Here, we give a comprehensive review of the existing knowledge of lncRNAs. Our aim is to provide a better understanding of the diversity of lncRNA structure and functions in brain development and disease. This holds promise for unravelling the complexity of neurodevelopmental and neurodegenerative disorders, paving the way for the development of novel biomarkers and therapeutic targets for improved diagnosis and treatment.

Study of lncRNAs in Pediatric Neurological Diseases: Methods, Analysis of the State-of-Art and Possible Therapeutic Implications

Long non-coding RNAs (lncRNAs) have emerged as crucial regulators in various cellular processes, and their roles in pediatric neurological diseases are increasingly being explored. This review provides an overview of lncRNA implications in the central nervous system, both in its physiological state and when a pathological condition is present. We describe the role of lncRNAs in neural development, highlighting their significance in processes such as neural stem cell proliferation, differentiation, and synaptogenesis. Dysregulation of specific lncRNAs is associated with multiple pediatric neurological diseases, such as neurodevelopmental or neurodegenerative disorders and brain tumors. The collected evidence indicates that there is a need for further research to uncover the full spectrum of lncRNA involvement in pediatric neurological diseases and brain tumors. While challenges exist, ongoing advancements in technology and our understanding of lncRNA biology offer hope for future breakthroughs in the field of pediatric neurology, leveraging lncRNAs as potential therapeutic targets and biomarkers.

Long non-coding RNAs in schizophrenia: Genetic variations, treatment markers and potential targeted signaling pathways

Schizophrenia (SZ), a complex and debilitating spectrum of psychiatric disorders, is now mainly attributed to multifactorial etiology that includes genetic and environmental factors. Long non-coding RNAs (lncRNAs) are gaining popularity as a way to better understand the comprehensive mechanisms beneath the clinical manifestation of SZ. Only in recent years has it been elucidated that mammalian genomes encode thousands of lncRNAs. Strikingly, roughly 30-40% of these lncRNAs are extensively expressed in different regions across the brain, which may be closely associated with SZ. The therapeutic and adverse effects of atypical antipsychotic drugs (AAPDs) are partially reflected by their role in the regulation of lncRNAs. This begs the question directly, do any lncRNAs exist as biomarkers for AAPDs treatment? Furthermore, we comprehend a range of mechanistic investigations that have revealed the regulatory roles for lncRNAs both involved in the brain and the periphery of SZ. More crucially, we also combine insights from a variety of signaling pathways to argue that lncRNAs probably play critical roles in SZ via their interactive downstream factors. This review provides a thorough understanding regarding dysregulation of lncRNAs, corresponding genetic alternations, as well as their potential regulatory roles in the pathology of SZ, which might help reveal useful therapeutic targets in SZ.

Ketamine modulates neural stem cell differentiation by regulating TRPC3 expression through the GSK3β/β-catenin pathway

Ketamine, a popular anesthetic, is often abused by people for its hallucinogenic effect. Thus, the safety of ketamine in pediatric populations has been called into question for potential neurotoxic effects. However, ketamine also has neuroprotective effects in many brain injury models. The differentiation of neural stem cells (NSCs) was influenced significantly by ketamine, but the molecular mechanism is still unclear. NSCs were extracted from the hippocampi of postnatal day 1 rats and treated with ketamine to induce NSCs differentiation. Our results found that ketamine promoted neuronal differentiation of NSCs dose-dependently in a small dose range (P < 0.001). The main types of neurons from NSCs were cholinergic (51 ± 4 %; 95 % CI: 41-61 %) and glutamatergic neurons (34 ± 3 %; 95 % CI: 27-42 %). Furthermore, we performed RNA sequencing to promise a more comprehensive understanding of the molecules regulated by ketamine. Finally, we combined bioimaging and multiple molecular biology techniques to clarify that ketamine influences NSC differentiation by regulating transient receptor potential canonical 3 (TRPC3) expressions. Ketamine dramatically repressed TRPC3 expression (MD [95 % CI]=0.67 [0.40-0.95], P < 0.001) with a significant increase of phosphorylated glycogen synthase kinase 3β (p-GSK3β; MD [95 % CI]=1.00 [0.74-1.27], P < 0.001) and a decrease of β-catenin protein expression (MD [95 % CI]=0.60 [0.32-0.89], P = 0.001), thereby promoting the differentiation of NSCs into neurons and inhibiting their differentiation into astrocytes. These results suggest that TRPC3 is necessary for ketamine to modulate NSC differentiation, which occurs partly via regulation of the GSK3β/β-catenin pathway.

Non-Coding RNAs in the Regulation of Hippocampal Neurogenesis and Potential Treatment Targets for Related Disorders

Non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, circRNAs, and piRNAs, do not encode proteins. Nonetheless, they have critical roles in a variety of cellular activities-such as development, neurogenesis, degeneration, and the response to injury to the nervous system-via protein translation, RNA splicing, gene activation, silencing, modifications, and editing; thus, they may serve as potential targets for disease treatment. The activity of adult neural stem cells (NSCs) in the subgranular zone of the hippocampal dentate gyrus critically influences hippocampal function, including learning, memory, and emotion. ncRNAs have been shown to be involved in the regulation of hippocampal neurogenesis, including proliferation, differentiation, and migration of NSCs and synapse formation. The interaction among ncRNAs is complex and diverse and has become a major topic within the life science. This review outlines advances in research on the roles of ncRNAs in modulating NSC bioactivity in the hippocampus and discusses their potential applications in the treatment of illnesses affecting the hippocampus.

Noncoding RNA therapeutics for substance use disorder

Although noncoding RNAs (ncRNAs) have been shown to regulate maladaptive neuroadaptations that drive compulsive drug use, ncRNA-targeting therapeutics for substance use disorder (SUD) have yet to be clinically tested. Recent advances in RNA-based drugs have improved many therapeutic issues related to immune response, specificity, and delivery, leading to multiple successful clinical trials for other diseases. As the need for safe and effective treatments for SUD continues to grow, novel nucleic acid-based therapeutics represent an appealing approach to target ncRNA mechanisms in SUD. Here, we review ncRNA processes implicated in SUD, discuss recent therapeutic approaches for targeting ncRNAs, and highlight potential opportunities and challenges of ncRNA-targeting therapeutics for SUD.

lncRNA BDNF-AS Attenuates Propofol-Induced Apoptosis in HT22 Cells by Modulating the BDNF/TrkB Pathway

Propofol is widely used as an intravenous anesthetic in clinical practice. Previous studies have indicated that propofol induces apoptosis in neurons. Brain-derived neurotrophic factor (BDNF), a neurotrophic factor, is associated with neuronal apoptosis. BDNF-AS, a relatively conserved long non-coding RNA, can reverse the transcription of BDNF. This study aimed to investigate the involvement of BDNF-AS in propofol-induced apoptosis in HT22 cells. HT22 cells were treated with various concentrations of propofol at different time points. BDNF-AS was silenced using BDNF-AS-targeting siRNA. TrkB was antagonized by the TrkB inhibitor, ANA-12. Flow cytometry, quantitative reverse-transcription PCR, and western blotting were performed to analyze apoptosis and the expression of genes and proteins, respectively. In propofol-treated HT22 cells, BDNF-AS was upregulated, and BDNF was downregulated in a time- and dose-dependent manner. BDNF-AS downregulation mediated by siRNA mitigated apoptosis, upregulated the expression of Bcl-2, and downregulated the expression of Bax and caspase-3, 7, and 9. ANA-12 downregulated the expression of Bcl-2, upregulated the expression of Bax and caspase-3, 7, and 9, and increased apoptosis. Our study implied that inhibition of BDNF-AS can decrease propofol-induced apoptosis by activating the BDNF/TrkB pathway. Thus, the BDNF-AS-BDNF/TrkB signaling pathway may be a valuable target for treating propofol-induced neurotoxicity.

Current and Future Perspectives of Noncoding RNAs in Brain Function and Neuropsychiatric Disease

Noncoding RNAs (ncRNAs) represent the majority of the transcriptome and play important roles in regulating neuronal functions. ncRNAs are exceptionally diverse in both structure and function and include enhancer RNAs, long ncRNAs, and microRNAs, all of which demonstrate specific temporal and regional expression in the brain. Here, we review recent studies demonstrating that ncRNAs modulate chromatin structure, act as chaperone molecules, and contribute to synaptic remodeling and behavior. In addition, we discuss ncRNA function within the context of neuropsychiatric diseases, particularly focusing on addiction and schizophrenia, and the recent methodological developments that allow for better understanding of ncRNA function in the brain. Overall, ncRNAs represent an underrecognized molecular contributor to complex neuronal processes underlying neuropsychiatric disorders.

Emerging roles of long non-coding RNAs in spinal cord injury

Spinal cord injury (SCI) is the most serious complication of spinal injury and often leads to severe dysfunction of the limb below the injured segment. SCI causes not only serious physical and psychological harm to the patients, but imposes an enormous economic burden on the whole society. Great efforts have been made to improve the functional outcomes of patients with SCI; however, therapeutic advances have far been limited. Long non-coding RNA (lncRNA) is an important regulator of gene expression and has recently been characterized as a key regulator of central nervous system stabilization. Emerging evidence suggested that lncRNAs are significantly dysregulated and play a key role in the development of SCI. Our review summarizes current researches regarding the roles of deregulated lncRNAs in modulating apoptosis, inflammatory response, neuronal behavior in SCI. These studies suggest that specific regulation of lncRNA or its downstream targets may provide a new therapeutic approach for this desperate disease.

Neuron-Glia Crosstalk Plays a Major Role in the Neurotoxic Effects of Ketamine via Extracellular Vesicles

Background: There is a compelling evidence from animal models that early exposure to clinically relevant general anesthetics (GAs) interferes with brain development, resulting in long-lasting cognitive impairments. Human studies have been inconclusive and are challenging due to numerous confounding factors. Here, we employed primary human neural cells to analyze ketamine neurotoxic effects focusing on the role of glial cells and their activation state. We also explored the roles of astrocyte-derived extracellular vesicles (EVs) and different components of the brain-derived neurotrophic factor (BDNF) pathway.

Methods: Ketamine effects on cell death were analyzed using live/dead assay, caspase 3 activity and PARP-1 cleavage. Astrocytic and microglial cell differentiation was determined using RT-PCR, ELISA and phagocytosis assay. The impact of the neuron-glial cell interactions in the neurotoxic effects of ketamine was analyzed using transwell cultures. In addition, the role of isolated and secreted EVs in this cross-talk were studied. The expression and function of different components of the BDNF pathway were analyzed using ELISA, RT-PCR and gene silencing.

Results: Ketamine induced neuronal and oligodendrocytic cell apoptosis and promoted pro-inflammatory astrocyte (A1) and microglia (M1) phenotypes. Astrocytes and microglia enhanced the neurotoxic effects of ketamine on neuronal cells, whereas neurons increased oligodendrocyte cell death. Ketamine modulated different components in the BDNF pathway: decreasing BDNF secretion in neurons and astrocytes while increasing the expression of p75 in neurons and that of BDNF-AS and pro-BDNF secretion in both neurons and astrocytes. We demonstrated an important role of EVs secreted by ketamine-treated astrocytes in neuronal cell death and a role for EV-associated BDNF-AS in this effect.

Conclusions: Ketamine exerted a neurotoxic effect on neural cells by impacting both neuronal and non-neuronal cells. The BDNF pathway and astrocyte-derived EVs represent important mediators of ketamine effects. These results contribute to a better understanding of ketamine neurotoxic effects in humans and to the development of potential approaches to decrease its neurodevelopmental impact.

A concise review on the role of BDNF-AS in human disorders

Brain-derived neurotrophic factor-antisense (BDNF-AS) is a long non-coding RNA with tens of alternatively spliced variants being transcribed from 11p14 cytogenetic band. As a naturally occurring anti-sense, it regulates expression of BDNF, a factor which as essential roles in the pathoetiology of neurodevelopmental diseases. Notably, BDNF-AS has been reported to be down-regulated in colorectal cancer, osteosarcoma, esophageal cancer, glioblastoma, prostate cancer, cervical cancer and breast cancer. This lncRNA has direct/indirect functional interactions with GSK-3β, EZH2, miR-214, PABPC1, RAX2, DLG5, p53 and ADAR as well as RNH1/TRIM21/mTOR signaling. In prostate and breast cancers, down-regulation of BDNF-AS has been associated with poor clinical outcome. In the present review, we assessed the existing literature on the role of BDNF-AS in this process and summarized the available data in three distinct sections based of the methodology of experiments and source of expression assays. We also summarized the role of BDNF-AS in non-neoplastic conditions.

Emerging Role of Long Noncoding RNAs in Perioperative Neurocognitive Disorders and Anesthetic-Induced Developmental Neurotoxicity

Preclinical investigations in animal models have consistently demonstrated neurobiological changes and life-long cognitive deficits following exposure to widely used anesthetics early in life. However, the mechanisms by which these exposures affect brain function remain poorly understood, therefore, limiting the efficacy of current diagnostic and therapeutic options in human studies. The human brain exhibits an abundant expression of long noncoding RNAs (lncRNAs). These biologically active transcripts play critical roles in a diverse array of functions, including epigenetic regulation. Changes in lncRNA expression have been linked with brain development, normal CNS processes, brain injuries, and the development of neurodegenerative diseases, and many lncRNAs are known to have brain-specific expression. Aberrant lncRNA expression has also been implicated in areas of growing importance in anesthesia-related research, including anesthetic-induced developmental neurotoxicity (AIDN), a condition defined by neurological changes occurring in patients repeatedly exposed to anesthesia, and the related condition of perioperative neurocognitive disorder (PND). In this review, we detail recent advances in PND and AIDN research and summarize the evidence supporting roles for lncRNAs in the brain under both normal and pathologic conditions. We also discuss lncRNAs that have been linked with PND and AIDN, and conclude with a discussion of the clinical potential for lncRNAs to serve as diagnostic and therapeutic targets for the prevention of these neurocognitive disorders and the challenges facing the identification and characterization of associated lncRNAs.

Research progress of lncRNAs in diabetic retinopathy

Diabetic retinopathy (DR), which is known as a severe complication of type 2 diabetes mellitus, can cause varying degrees of damage to visual acuity. The pathogenesis of DR is multifactorial and not fully understood. Many previous research studies have revealed that an aberrant level of some long non-coding RNAs (lncRNAs) may accelerate the development of DR. These lncRNAs are regulatory factors and research related to them is always underway. In this review, we will update several types of lncRNAs based on the previous studies which are related to the development of DR and discuss its potential mechanisms of action and connections. Generally, the review will help us know more about lncRNAs and provide directions for future research related to DR.

HDAC6 is critical for ketamine-induced impairment of dendritic and spine growth in GABAergic projection neurons

Ketamine is widely used in infants and children for anesthesia; both anesthetic and sub-anesthetic doses of ketamine have been reported to preferentially inhibit the GABAergic neurons. Medium spiny neurons (MSNs), the GABAergic projection neurons in the striatum, are vulnerable to anesthetic exposure in the newborn brain. Growth of dendrites requires a deacetylase to remove acetyl from tubulin in the growth cone to destabilize the tubulin. Histone deacetylase 6 (HDAC6) affects microtubule dynamics, which are involved in neurite elongation. In this study we used a human induced pluripotent stem cells (iPSCs)-derived striatal GABA neuron system to investigate the effects of ketamine on HDAC6 and the morphological development of MSNs. We showed that exposure to ketamine (1-500 μM) decreased dendritic growth, dendrite branches, and dendritic spine density in MSNs in a time- and concentration-dependent manner. We revealed that ketamine treatment concentration-dependently inhibited the expression of HDAC6 or aberrantly translocated HDAC6 into the nucleus. Ketamine inhibition on HDAC6 resulted in α-tubulin hyperacetylation, consequently increasing the stability of microtubules and delaying the dendritic growth of MSNs. Finally, we showed that the effects of a single-dose exposure on MSNs were reversible and lasted for at least 10 days. This study reveals a novel role of HDAC6 as a regulator for ketamine-induced deficits in the morphological development of MSNs and provides an innovative method for prevention and treatment with respect to ketamine clinical applications.

Dysregulation of long non-coding RNAs and their mechanisms in Huntington's disease

Extensive alterations in gene regulatory networks are a typical characteristic of Huntington's disease (HD); these include alterations in protein-coding genes and poorly understood non-coding RNAs (ncRNAs), which are associated with pathology caused by mutant huntingtin. Long non-coding RNAs (lncRNAs) are an important class of ncRNAs involved in a variety of biological functions, including transcriptional regulation and post-transcriptional modification of many targets, and likely contributed to the pathogenesis of HD. While a number of changes in lncRNAs expression have been observed in HD, little is currently known about their functions. Here, we discuss their possible mechanisms and molecular functions, with a particular focus on their roles in transcriptional regulation. These findings give us a better insight into HD pathogenesis and may provide new targets for the treatment of this neurodegenerative disease.

LncRNA SNHG15 Knockdown Protects Against OGD/R-Induced Neuron Injury by Downregulating TP53INP1 Expression via Binding to miR-455-3p

Cerebral ischemia-reperfusion (I/R) injury is the common symptom of ischemic stroke, which poses a heavy burden to human health. Long non-coding RNA (lncRNA) is indicated to be a critical regulator in cerebral ischemia. This study aims to reveal the effects of lncRNA small nucleolar RNA host gene 15 (SNHG15) on oxygen-glucose deprivation and reoxygenation (OGD/R)-induced neuron injury and underlying mechanism. The expression levels of SNHG15, microRNA-455-3p (miR-455-3p) and tumour protein p53 inducible nuclear protein 1 (TP53INP1) mRNA were determined by quantitative real time polymerase chain reaction in P12 cells. The protein levels of TP53INP1, cleaved caspase-3, caspase-3, B-cell lymphoma-2 and BCL2-associated x protein (Bax) were detected by western blot in P12 cells. Cell viability and apoptosis were revealed by cell counting kit-8 assay and flow cytometry analysis, respectively, in P12 cells. Caspase-3 activity, the levels of tumor necrosis factor-α and interleukin-1β and the production of reactive oxygen species (ROS) were severally determined by caspase-3 activity assay, Enzyme-linked immunosorbent assay and ROS detection assay in P12 cells. The binding relationship between miR-455-3p and SNHG15 or TP53INP1 was predicted by starbase online database, and identified by dual-luciferase reporter, RNA pull-down or RNA immunoprecipitation assay. SNHG15 expression and the mRNA and protein levels of TP53INP1 were dramatically upregulated, while miR-455-3p expression was apparently downregulated in OGD/R-induced PC12 cells. SNHG15 silencing hindered the effects of OGD/R treatment on cell viability, apoptosis, inflammation and oxidative in PC12 cells; however, these impacts were restored after miR-455-3p inhibitor transfection. Additionally, SNHG15 acted as a sponge of miR-455-3p and miR-455-3p bound to TP53INP1. SNHG15 contributed to OGD/R-induced neuron injury by regulating miR-455-3p/TP53INP1 axis, which provided a novel insight to study lncRNA-directed therapy in ischemia stoke.

Lithium alleviated spinal cord injury (SCI)-induced apoptosis and inflammation in rats via BDNF-AS/miR-9-5p axis

Spinal cord injury (SCI) is a major cause of paralysis, disability and even death in severe cases. Lithium has neuroprotective effects on SCI, while the underlying mechanisms remain obscure. In the present study, we established a SCI rat model, which subsequently received lithium treatment. Results displayed that lithium treatment improved the locomotor function recovery and reduced apoptosis by increasing anti-apoptotic molecule expression and decreasing pro-apoptotic factor expression in SCI rats. Furthermore, lithium treatment alleviated the inflammatory response by inactivating the nuclear factor-kappa B (NF-κB) pathway and inhibited the expression of lncRNA brain-derived neurotrophic factor antisense (BDNF-AS) in SCI rats. Subsequent researches indicated that miR-9-5p was targeted and regulated by BDNF-AS. Lithium treatment rescued the upregulation of BDNF-AS expression and downregulation of miR-9-5p expression induced by H₂O₂ in SH-SY5Y cells. BDNF-AS overexpression or miR-9-5p interference attenuated the anti-apoptotic and anti-inflammatory effects of lithium chloride in SH-SY5Y cells that was damaged by H₂O₂ induction, revealing that lithium might act through the BDNF-AS/miR-9-5p axis. In vivo studies showed that the injection of BDNF-AS adenovirus vector or miR-9-5p inhibitor reversed the effects of lithium on the histologic morphology of spinal cord, motor function, inflammatory reaction and apoptosis in SCI rats, which was consistent with the results of in vitro studies. In conclusion, our data demonstrated that lithium reduced SCI-induced apoptosis and inflammation in rats via the BDNF-AS/miR-9-5p axis.

LncRNA KCNQ1OT1 Sponges miR-206 to Ameliorate Neural Injury Induced by Anesthesia via Up-Regulating BDNF

OBJECTIVE

Widely used in anesthesia, ketamine is reported to induce neurotoxicity in patients. This study aimed to investigate the molecular regulatory mechanism of long non-coding RNA (lncRNA) KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) in ameliorating ketamine-induced neural injury.

MATERIALS AND METHODS

Sprague-Dawley rats were intraperitoneally injected with ketamine to induce neuronal injury. PC-12 cells treated with ketamine were used as the cell model. Ketamine-induced aberrant expression of KCNQ1OT1, miR-206 and brain-derived neurotrophic factor (BDNF) were examined by quantitative real-time polymerase chain reaction (qRT-PCR). The effects of KCNQ1OT1 and miR-206 on ketamine-induced neural injury in PC-12 cells were then examined by MTT and LDH assay. The regulatory relationships between KCNQ1OT1 and miR-206, and miR-206 and BDNF were detected by dual-luciferase reporter assay.

RESULTS

Ketamine induced the apoptosis of neurons of the hippocampus in rats, and the apoptosis of PC-12 cells, accompanied by down-regulation of KCNQ1OT1 and BDNF expressions, and up-regulation of miR-206 expression. Overexpression of KCNQ1OT1 enhanced the resistance to apoptosis of PC-12 cells and significantly ameliorated ketamine-induced nerve injury, while transfection of miR-206 had opposite effects. Mechanistically, KCNQ1OT1 could target miR-206 and reduce its expression level, in turn indirectly increase the expression level of BDNF, and play a protective role in neural injury.

CONCLUSION

KCNQ1OT1/miR-206/BDNF axis is demonstrated to be an important regulatory mechanism in regulating ketamine-induced neural injury. Our study helps to clarify the mechanism by which ketamine exerts its toxicological effects and provides clues for the neuroprotection during anesthesia.

Silencing of long non‑coding antisense RNA brain‑derived neurotrophic factor attenuates hypoxia/ischemia‑induced neonatal brain injury

Hypoxic/ischemic (HI) brain damage (HIBD) is a major cause of acute neonatal brain injury, leading to high mortality and serious neurological deficits. The antisense RNA of brain-derived neurotrophic factor (BDNF-AS) is transcribed from the opposite strand of the BDNF gene. The aim of the present study was to investigate the role of BDNF-AS in HI-induced neuronal cell injury in vivo and in vitro. Reverse transcription-quantitative PCR (RT-qPCR) assays indicated that BDNF-AS expression was significantly upregulated in HI-injured neonatal brains and hippocampal neurons. However, BDNF expression was downregulated in HI-injured neonatal brains and hippocampal neurons. Cell Counting Kit-8 assays, Hoechst staining, calcein-AM/PI staining, immunostaining, water maze tests and rotarod tests demonstrated that BDNF-AS silencing protected against hypoxia-induced primary hippocampal neuron injury in vitro and HI-induced brain injury in vivo. Mechanistically, RT-qPCR assays and western blotting indicated that BDNF-AS silencing led to increased expression of BDNF and activated the BDNF-mediated signaling pathway, as demonstrated by increased expression levels of BDNF, phosphorylated-Akt and phosphorylated-tropomyosin receptor kinase B. Collectively, the present study provides important insights into the pathogenesis of HIBD, and it was indicated that BDNF-AS silencing may be a promising approach for the treatment of neonatal HIBD.

The functions of long non-coding RNAs in neural stem cell proliferation and differentiation

The capacities for neural stem cells (NSCs) self-renewal with differentiation are need to be precisely regulated for ensuring brain development and homeostasis. Recently, increasing number of studies have highlighted that long non-coding RNAs (lncRNAs) are associated with NSC fate determination during brain development stages. LncRNAs are a class of non-coding RNAs more than 200 nucleotides without protein-coding potential and function as novel critical regulators in multiple biological processes. However, the correlation between lncRNAs and NSC fate decision still need to be explored in-depth. In this review, we will summarize the roles and molecular mechanisms of lncRNAs focusing on NSCs self-renewal, neurogenesis and gliogenesis over the course of neural development, still more, dysregulation of lncRNAs in all stage of neural development have closely relationship with development disorders or glioma. In brief, lncRNAs may be explored as effective modulators in NSCs related neural development and novel biomarkers for diagnosis and prognosis of neurological disorders in the future.

PABPC1-induced stabilization of BDNF-AS inhibits malignant progression of glioblastoma cells through STAU1-mediated decay

Glioblastoma is the most common and malignant form of primary central nervous tumor in adults. Long noncoding RNAs (lncRNAs) have been reported to play a pivotal role in modulating gene expression and regulating human tumor’s malignant behaviors. In this study, we confirmed that lncRNA brain-derived neurotrophic factor antisense (BDNF-AS) was downregulated in glioblastoma tissues and cells, interacted and stabilized by polyadenylate-binding protein cytoplasmic 1 (PABPC1). Overexpression of BDNF-AS inhibited the proliferation, migration, and invasion, as well as induced the apoptosis of glioblastoma cells. In the in vivo study, PABPC1 overexpression combined with BDNF-AS overexpression produced the smallest tumor and the longest survival. Moreover, BDNF-AS could elicit retina and anterior neural fold homeobox 2 (RAX2) mRNA decay through STAU1-mediated decay (SMD), and thereby regulated the malignant behaviors glioblastoma cells. Knockdown of RAX2 produced tumor-suppressive function in glioblastoma cells and increased the expression of discs large homolog 5 (DLG5), leading to the activation of the Hippo pathway. In general, this study elucidated that the PABPC1-BDNF-AS-RAX2-DLG5 mechanism may contribute to the anticancer potential of glioma cells and may provide potential therapeutic targets for human glioma.

Activation of BDNF-AS/ADAR/p53 Positive Feedback Loop Inhibits Glioblastoma Cell Proliferation

Despite progress in conventional treatment for glioblastoma (GBM), the prognosis remains poor due to high tumor recurrence. Therefore, identification of new molecular mechanisms is a pressing need for betterment of GBM patient outcomes. qRT-PCR was used to determine BDNF-AS expression in GBM cells. CCK-8, EdU incorporation, and caspase-3 activity assays were employed to analyze biological functions of BDNF-AS. RIP and RNA pull-down were conducted to detect the interactions among BDNF-AS, ADAR, and p53. Actinomycin D was utilized to examine the stability of p53 mRNA. ChIP and luciferase reporter assays were performed to detect transcriptional activation of BDNF-AS by p53. We found that BDNF-AS was significantly downregulated in GBM cell lines, and its overexpression inhibited GBM cell growth, and promoted apoptosis. Importantly, we illustrated that BDNF-AS coupled with ADAR protein to potentiate stability of p53 mRNA and thus upregulate p53. Interestingly, we further identified p53 as a transcription factor of BDNF-AS, activating transcription of BNDF-AS. This study firstly demonstrated that BDNF-AS acted as a tumor suppressor in GBM and the positive feedback circuit of BDNF-AS/ADAR/p53 served an important mechanism to control GBM proliferation. Targeting this auto-regulatory loop may provide a potential therapeutic strategy for GBM patients.

Long Non-coding RNA in CNS Injuries: A New Target for Therapeutic Intervention

CNS injuries, such as traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), and cerebral ischemic stroke, are important causes of death and long-term disability worldwide. As an important class of pervasive genes involved in many pathophysiological processes, long non-coding RNAs (lncRNAs) have received attention in the past decades. Multiple studies indicate that lncRNAs are abundant in the CNS and have a key role in brain function as well as many neurological disorders, especially in CNS injuries. Several investigations have deciphered that regulation of lncRNAs exert pro-angiogenesis, anti-apoptosis, and anti-inflammation effects in CNS injury via different molecules and pathways, including microRNA (miRNA), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B (PI3K/AKT), Notch, and p53. Thus, lncRNAs show great promise as molecular targets in CNS injuries. In this article, we provide an updated review of the current state of our knowledge about the relationship between lncRNAs and CNS injuries, highlighting the specific roles of lncRNAs in CNS injuries.

LncRNA BDNF-AS is associated with the malignant status and regulates cell proliferation and apoptosis in osteosarcoma

Long non-coding RNA (LncRNA) brain-derived neurotrophic factor antisense (BDNF-AS) has been found to be down-regulated and function in a tumor suppressive role in human cancers. However, the expression status and function of BDNF-AS is still unknown in osteosarcoma (OS). In our study, BDNF-AS expression was found to be decreased in OS tissues and cells. Moreover, BDNF-AS low expression was correlated with advanced Enneking stage, large tumor size and poor prognosis in OS patients. The multivariate analysis suggested low expression of BDNF-AS was an independent unfavorable prognostic factor for overall survival in OS patients. The in vitro studies indicated that BDNF-AS overexpression inhibits OS cell proliferation and promotes cell apoptosis through regulating cleaved caspase-3. In conclusion, BDNF-AS serves as a tumor suppressive lncRNA in OS.

MicroRNA-107 regulates anesthesia-induced neural injury in embryonic stem cell derived neurons

Ketamine, though widely used in pediatric anesthesia, may induce cortical neurotoxicity in young patients. This study focused on an in vitro model of rat brain embryonic stem cell (ESC)-derived neurons to investigate the effects of microRNA-107 (miR-107) on ketamine-induced neural injury. Rat brain ESCs were proliferated in vitro and differentiated toward neuronal fate. Ketamine induced neural injury in ESC-derived neurons was inspected by TUNEL and neurite growth assays. Ketamine-induce aberrant miR-107 expression was examined by qRT-PCR. MiR-107 was downregulated in ESCs through lentiviral transduction. Its effect on ketamine-induced neural injury in ESC-derived neurons was then examined. Potential downstream target of miR-107, brain derived neurotrophin factor (BDNF), was inspected by dual-luciferase reporter assay and qRT-PCR. BDNF was knocked down, through siRNA transfection, in NSCs to investigate its functional involvement in miR-107 mediated neural protection in ketamine-injured NSC-derived neurons. Ketamine induced apoptosis, neurite degeneration, and upregulated miR-107 in NSC-derived neurons. Lentivirus-mediated miR-107 downregulation attenuated ketamine-induced neural injury. BDNF was proven to be directly and inversely regulated by miR-107 in NSC-derived neurons. SiRNA-mediated BDNF inhibition reversed the protective effect of miR-107 downregulation on ketamine injury in NSC-derived neurons. MiR-107 / BDNF was demonstrated to be an important epigenetic signaling pathway in regulating ketamine-induced neural injury in cortical neurons. © 2018 The Authors. IUBMB Life published by Wiley Periodicals,Inc. on behalf of International Union of Biochemistry and Molecular Biology., 71(1):20-27, 2019.

Propofol Alters Long Non-Coding RNA Profiles in the Neonatal Mouse Hippocampus: Implication of Novel Mechanisms in Anesthetic-Induced Developmental Neurotoxicity

BACKGROUND

Propofol induces acute neurotoxicity (e.g., neuroapoptosis) followed by impairment of long-term memory and learning in animals. However, underlying mechanisms remain largely unknown. Long non-coding RNAs (lncRNAs) are found to participate in various pathological processes. We hypothesized that lncRNA profile and the associated signaling pathways were altered, and these changes might be related to the neurotoxicity observed in the neonatal mouse hippocampus following propofol exposure.

METHODS

In this laboratory experiment, 7-day-old mice were exposed to a subanesthetic dose of propofol for 3 hours, with 4 animals per group. Hippocampal tissues were harvested 3 hours after propofol administration. Neuroapoptosis was analyzed based on caspase 3 activity using a colorimetric assay. A microarray was performed to investigate the profiles of 35,923 lncRNAs and 24,881 messenger RNAs (mRNAs). Representative differentially expressed lncRNAs and mRNAs were validated using reverse transcription quantitative polymerase chain reaction. All mRNAs dysregulated by propofol and the 50 top-ranked, significantly dysregulated lncRNAs were subject to bioinformatics analysis for exploring the potential mechanisms and signaling network of propofol-induced neurotoxicity.

RESULTS

Propofol induced neuroapoptosis in the hippocampus, with differential expression of 159 lncRNAs and 100 mRNAs (fold change ± 2.0, P< 0.05). Bioinformatics analysis demonstrated that these lncRNAs and their associated mRNAs might participate in neurodegenerative pathways (e.g., calcium handling, apoptosis, autophagy, and synaptogenesis).

CONCLUSION

This novel report emphasizes that propofol alters profiles of lncRNAs, mRNAs, and their cooperative signaling network, which provides novel insights into molecular mechanisms of anesthetic-induced developmental neurodegeneration and preventive targets against the neurotoxicity.

Knockdown of lncRNA BDNF-AS suppresses neuronal cell apoptosis via downregulating miR-130b-5p target gene PRDM5 in acute spinal cord injury

OBJECTIVE

The present study was designed to investigate the molecular mechanism and biological roles of lncRNA brain-derived neurotrophic factor antisense (lncRNA BDNF-AS) in acute spinal cord injury (ASCI).

METHODS

The rat model of ASCI and hypoxic cellular model were established to detect the expression of BDNF-AS, miR-130b-5p, PR (PRDI-BF1 and RIZ) domain protein 5 (PRDM5) and cleaved caspase 3 (c-caspase 3) using qRT-PCR and western blot. Basso, Beattie and Bresnahan (BBB) score was carried out to assess neurological function. Flow cytometry was used to determine the apoptosis of neuronal cells. The association among BDNF-AS, miR-130b-5p and PRDM5 were disclosed by RNA immunoprecipitation (RIP) assay, RNA pull-down assay and dual-luciferase reporter assay.

RESULTS

BDNF-AS, PRDM5 and c-caspase 3 expression were significantly upregulated, while miR-130b-5p was suppressed in the ASCI group and neuronal cells following hypoxia treatment. BDNF-AS knockdown inhibited neuronal cell apoptosis. Further studies indicated that BDNF-AS functioned as a competing endogenous RNA (ceRNA) by sponging miR-130b-5p in neuronal cells. Further investigations demonstrated that PRDM5 was a target of miR-130b-5p and BDNF-AS knockdown exerted anti-apoptotic effects via miR-130b-5p/PRDM5 axis.

CONCLUSION

The lncRNA BDNF-AS/miR-130b-5p/PRDM5 axis might be a promising therapeutic target for ASCI.

LncRNA BDNF-AS inhibits proliferation, migration, invasion and EMT in oesophageal cancer cells by targeting miR-214

This study was aimed at exploring the effect of lncRNA BDNF-AS on cell proliferation, migration, invasion and epithelial-to-mesenchymal transition (EMT) of oesophageal cancer (EC) cells. The expression of BDNF-AS and miR-214 in tissue samples and cells was measured by qRT-PCR. The targeted relationship between BDNF-AS and miR-214 was analysed by dual-luciferase reporter assay. After cell transfection, the cell proliferation activity was assessed by MTS method, while the migrating and invading abilities were evaluated by transwell assay. LncRNA BDNF-AS was remarkably down-regulated, while miR-214 was up-regulated in EC tissues and cells in comparison with normal tissues and cells. Overexpression of BDNF-AS significantly inhibited the abilities of cell proliferation, migration and invasion as well as the EMT processes of EC cells. The bioinformatics analysis and luciferase assay indicated that BDNF-AS could be directly bound by miR-214. Furthermore, overexpression of miR-214 and BDNF-AS exerted suppressive influence on EC cell multiplication, migration, invasion and EMT processes. LncRNA BDNF-AS restrained cell proliferation, migration, invasion and EMT processes in EC cells by targeting miR-214.

Epigenetic Alterations in Anesthesia-Induced Neurotoxicity in the Developing Brain

Before birth and early in life, the developing brain is particularly sensitive to environmental and pharmacological influences. Increasing experimental evidence suggests that an association exists between exposure to anesthesia during a vulnerable period of brain development and subsequent poor neurodevelopmental outcomes. However, the mechanisms underlying this association are not fully understood. Epigenetics, broadly defined as the regulation of gene expression without alterations of DNA sequence, has become a field of tremendous interest in neuroscience. In recent years, a growing body of literature suggests that anesthesia-induced long-term changes in gene transcription and functional deficits in learning and behavior later in life are mediated via epigenetic modifications. This brief review provides an overview of epigenetic mechanisms and highlights the emerging roles played by epigenetic dysfunctions in the processes of anesthesia-induced neurotoxicity in the developing brain. Epigenetic targeting of DNA methyltransferases and/or histone deacetylases may have some therapeutic value. Epigenetics may lead to the identification of novel markers that contribute toward considerable translational significance in the field of neuroprotection.

Silencing of LncRNA BDNF-AS attenuates Aβ25-35-induced neurotoxicity in PC12 cells by suppressing cell apoptosis and oxidative stress

OBJECTIVE

To explore the effects of long non-coding RNA (lncRNA) brain-derived neurotrophic factor anti-sense (BDNF-AS) on the Aβ_25-35-induced neurotoxicity in PC12 cells.

METHODS

PC12 cells were induced by Aβ_25-35 to construct cell injury models of Alzheimer's disease (AD), and then transfected with siRNA-BDNF-AS. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the expressions of BDNF-AS and BDNF. Besides, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Hoechst33342 staining were utilized to analyze the cell viability and apoptosis, respectively, Western blotting to evaluate the protein expressions, immunofluorescence to assess the Cytochrome C (Cyt C) release, and Rhodamine 123 (Rh123) to measure the mitochondrial membrane potential (MMP).The evaluation of oxidative stress was conducted via the determination of the levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT).

RESULTS

Aβ_25-35 apparently increased BDNF-AS but decreased BDNF in PC12 cells, which also reduced viability and induced apoptosis of PC12 cells. Silencing of BDNF-AS could significantly up-regulate BDNF in Aβ_25-35-induced PC12 cells, with the elevated cell viability. Moreover, silencing BDNF-AS inhibited the apoptosis of Aβ_25-35-induced PC12 cells, suppressed the release of Cyt C, reduced the expression of cleaved caspase-3 and Bax, and lowered the mean fluorescence intensity (MFI) of Rh123, but it elevated the expression of Bcl-2. Besides, silencing BDNF-AS also reduced ROS intensity and MDA content, but enhanced the activities of SOD and CAT.

CONCLUSION

Silencing BDNF-AS exerts protective functions to increase the viability, inhibit the apoptosis and oxidative stress of Aβ_25-35-induced PC12 cells by negative regulation of BDNF.

ABBREVIATIONS

Aβ_25-35: amyloid beta peptide 25-35; AD: Alzheimer's disease; LncRNA BDNF-AS: long non-coding RNA brain-derived neurotrophic factor anti-sense; OS: Oxidative stress.

Long noncoding RNA BDNF-AS is downregulated in cervical cancer and has anti-cancer functions by negatively associating with BDNF

PURPOSE

We investigated expression and mechanism long noncoding RNA BDNF-AS in human cervical cancer (CC).

METHODS

BDNF-AS expressions were examined by qPCR in CC cell lines and human CC tumors. CC cell lines, SiHa and DoTc2-4510 were transduced with lentivirus to ectopically overexpress BDNF-AS. Possible anti-cancer effects of BDNF overexpression were examined on CC in vitro proliferation and migration, and in vivo transplantation. Human BDNF gene expression was also examined in CC cell lines and tumors. In CC cells with overexpressed BDNF-AS, BDNF was upregulated to examine its direct effect in NDNF-AS-modulated CC proliferation and migration.

RESULTS

BDNF was downregulated in both CC cells and human CC tumors. In CC cells, BDNF-AS overexpression is anti-cancer by inhibiting proliferation and migration in vitro, and transplantation in vivo. BDNF was inversely expressed as BDNF-AS in CC. Upregulation of BDNF in BDNF-AS-overexpressed CC cells reversed the anti-cancer effects of BDNF-AS.

CONCLUSION

BDNF-AS is downregulated in CC. Overexpressing BDNF-AS may inhibit CC, possibly through inverse regulation on BDNF.

LncRNA SNHG1 regulates cerebrovascular pathologies as a competing endogenous RNA through HIF-1α/VEGF signaling in ischemic stroke

Studies have shown that long noncoding ribonucleic acids (lncRNAs) play critical roles in multiple biologic processes. However, the Small Nucleolar RNA Host Gene 1 (SNHG1) function and underlying molecular mechanisms in ischemic stroke have not yet been reported. In the present study, we found that SNHG1 expression was remarkably increased both in isolated cerebral micro-vessels of a middle cerebral artery occlusion (MCAO) mice model, and in oxygen-glucose deprivation (OGD)-cultured mice brain micro-vascular endothelial cells (BMECs), meanwhile, the SNHG1 level was negatively correlated with miR-18a in MCAO mice. Mechanistically, SNHG1 inhibition presents larger brain infarct size and worsens neurological scores in MCAO mice. Consistent with the in vivo findings, SNHG1 inhibition also significantly increased caspase-3 activity and cell apoptosis in OGD-cultured BMECs. Furthermore, we found that SNHG1 functions as a competing endogenous RNA (ceRNA) for miR-18a, thereby regulating the de-repression of its endogenous target HIF-1α and promoting BMEC survival through HIF-1α/VEGF signaling. This study found a neuroprotective effect of SNHG1 mediated by HIF-1α/VEGF signaling through acting as a ceRNA for miR-18a. These findings reveal a novel function of SNHG1, which contributes to an extensive understanding of ischemic stroke and provides novel therapeutic options for this disease.

Long non-coding RNA BDNF-AS modulates osteogenic differentiation of bone marrow-derived mesenchymal stem cells

For patients with osteoporosis, the inability of osteogenic differentiation is the key reason for bone loss. In this study, we investigated the expression and function of long non-coding RNA BDNF-AS in mesenchymal stem cell-derived osteogenic differentiation. Mouse bone marrow-derived mesenchymal stem cells (BMMSCs) were cultured in vitro and induced toward osteogenic differentiation. Quantitative real-time PCR (qRT-PCR) was used to evaluate gene expressions of BDNF-AS and BDNF during osteogenic differentiation. BMMSCs were also extracted from ovariectomized (OVX) mice. The dynamic change of BDNF-AS in OVX-derived BMMSCs during osteogenic differentiation was also evaluated. Lentivirus was used to upregulate BDNF-AS in BMMSCs. The effects of BDNF-AS upregulation on BMMSCs' proliferation and osteogenic differentiation were then evaluated. In addition, qRT-PCR and western blot were applied to further examine the effect of BDNF-AS upregulation on osteogenesis-associated signaling pathways, including BDNF, OPN, and Runx2, in osteogenic differentiation. BDNF-AS was downregulated, whereas BDNF was upregulated in osteogenic differentiation of BMMSCs. Among OVX-derived BMMSCs, BDNF-AS expression was upregulated during osteogenic differentiation. Lentivirus-induced BDNF-AS upregulation promoted BMMSCs self-proliferation but inhibited osteogenic differentiation, as demonstrated by proliferation, alizarin red staining, and alkaline phosphatase activity assays, respectively. QRT-PCR and western blot demonstrated that BDNF, OPN, and Runx2 were downregulated by BDNF-AS upregulation in the differentiated BMMSCs. BDNF-AS is dynamically regulated in osteogenic differentiation. Upregulating BDNF-AS inhibits osteogenesis, possibly through inverse regulation on BDNF and osteogenic signaling pathways.

Inhibition of GSK-3beta Signaling Pathway Rescues Ketamine-Induced Neurotoxicity in Neural Stem Cell-Derived Neurons

Clinical application of anesthetic reagent, ketamine (Keta), may induce irreversible neurotoxicity in central nervous system. In this work, we utilized an in vitro model of neural stem cells-derived neurons (nSCNs) to evaluate the role of GSK-3 signaling pathway in Keta-induced neurotoxicity. Embryonic mouse-brain neural stem cells were differentiated into neurons in vitro. Keta (50 μM)-induced neurotoxicity in cultured nSCNs was monitored by apoptosis, immunohistochemical and western blot assays, respectively. GSK-3 signaling pathways, including GSK-3α and GSK-3β, were inhibited by siRNA in the culture. The subsequent effects of GSK-3α or GSK-3β downregulation on Keta-induced neurotoxicity, including apoptosis and neurite loss, were then evaluated in nSCNs. Finally, caspase and Akt/ERK signal pathways were further examined by western blot to evaluate the regulatory effect of GSK-3 signaling pathways on Keta-induced neural injury. Keta (50 μM) caused markedly nSCN apoptosis and neurite degeneration in vitro. Keta decreased GSK-3β phosphorylation, but had no effect on GSK-3α phosphorylation. SiRNA-induced GSK-3β downregulation rescued Keta-induced neurotoxicity in nSCNs by reducing neuronal apoptosis and preventing neurite degeneration. On the other hand, GSK-3α downregulation had no effect on Keta-induced neurotoxicity. Western blot showed that, in Keta-injured nSCNs, GSK-3β downregulation reduced Caspase-1/3 proteins, but left phosphorylated Akt/ERK unchanged. GSK-3β, not GSK-3α, was specifically involved in the process of Keta-induced neurotoxicity in nSCNs. Inhibiting GSK-3β may be an effective approach to counter toxic effect of ketamine on central neurons in clinical and experimental applications.

Long noncoding nature brain-derived neurotrophic factor antisense is associated with poor prognosis and functional regulation in non-small cell lung caner

In this study, we evaluated the prognostic potential and functional regulation of human nature antisense, brain-derived neurotrophic factor antisense, in non-small cell lung cancer. Non-small cell lung cancer carcinoma and adjacent non-carcinoma lung tissues were extracted from 151 patients. Their endogenous brain-derived neurotrophic factor antisense expression levels were compared by quantitative reverse transcription polymerase chain reaction. Clinical relevance between endogenous brain-derived neurotrophic factor antisense expression level and patients' clinicopathological variances or overall survival was analyzed. The potential of brain-derived neurotrophic factor antisense being an independent prognostic factor in non-small cell lung cancer was also evaluated. In in vitro non-small cell lung cancer cell lines, brain-derived neurotrophic factor antisense was upregulated through forced overexpression. The effects of brain-derived neurotrophic factor antisense upregulation on non-small cell lung cancer in vitro survival, proliferation, and migration were evaluated by viability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, and transwell assays. Brain-derived neurotrophic factor antisense is lowly expressed in non-small cell lung cancer carcinoma tissues and further downregulated in late-stage carcinomas. Brain-derived neurotrophic factor antisense downregulation was closely associated with non-small cell lung cancer patients' advanced tumor, lymph node, metastasis stage, and positive status of lymph node metastasis, and confirmed to be an independent prognostic factor for patients' poor overall survival. In non-small cell lung cancer A549 and H226 cell lines, forced overexpression of brain-derived neurotrophic factor antisense did not alter cancer cell viability but had significantly tumor suppressive effect in inhibiting in vitro non-small cell lung cancer proliferation and migration. Endogenous brain-derived neurotrophic factor antisense in non-small cell lung cancer carcinoma could be a potential biomarker for predicting patients' prognosis. Overexpressing brain-derived neurotrophic factor antisense may also have a therapeutic potential in inhibiting non-small cell lung cancer tumor growth.

Long noncoding RNA BDNF-AS is a potential biomarker and regulates cancer development in human retinoblastoma

BACKGROUND

Long non-coding RNAs (lncRNA) have been shown to play important roles in human cancer. We examined expression, prognostic potential and functional roles of lncRNA, brain-derived neurotrophic factor antisense (BDNF-AS) in human retinoblastoma (RB).

METHODS

BDNF-AS expression in RB tumors was characterized according to the clinicopathological parameters of patients. BDNF-AS mRNA level was compared between RB tumors and normal retinas, as well as RB cell lines and normal retinal epithelial cells. RB patients' overall survival was compared between those with low and high BDNF-AS tumor expressions. Statistical analysis was performed to examine the independence of BDNF-AS being cancer biomarker in RB. In Y79 and WERI-Rb-1 cells, BDNF-AS was upregulated. It's effect on cancer proliferation, migration and cell-cycle transition were assessed.

RESULTS

BDNF-AS is downregulated in RB tumors and cell lines. Low BDNF-AS expression in RB tumors is correlated with patients' advanced clinical stage and tumor differentiation status. Low BDNF-AS expression is associated with shorter overall survival and may be acting as an independent marker in RB. In Y79 and WERI-Rb-1 cells, forced overexpression of BDNF-AS inhibited cancer proliferation and migration. It also induced cell-cycle arrest at G0/G1 phase by downregulating CDC42, Cyclin E and BDNF.

CONCLUSION

BDNF-AS is lowly expressed, and may be used as a prognostic biomarker in RB. Upregulating BDNF-AS has inhibitory effect on RB development, probably through the suppression of cell-cycle transition.