The LncRNA H19/miR-1-3p/CCL2 axis modulates lipopolysaccharide (LPS) stimulation-induced normal human astrocyte proliferation and activation

C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 pathway as a therapeutic target and regulatory mechanism for spinal cord injury

Spinal cord injury involves non-reversible damage to the central nervous system that is characterized by limited regenerative capacity and secondary inflammatory damage. The expression of the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis exhibits significant differences before and after injury. Recent studies have revealed that the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis is closely associated with secondary inflammatory responses and the recruitment of immune cells following spinal cord injury, suggesting that this axis is a novel target and regulatory control point for treatment. This review comprehensively examines the therapeutic strategies targeting the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis, along with the regenerative and repair mechanisms linking the axis to spinal cord injury. Additionally, we summarize the upstream and downstream inflammatory signaling pathways associated with spinal cord injury and the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis. This review primarily elaborates on therapeutic strategies that target the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the latest progress of research on antagonistic drugs, along with the approaches used to exploit new therapeutic targets within the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the development of targeted drugs. Nevertheless, there are presently no clinical studies relating to spinal cord injury that are focusing on the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis. This review aims to provide new ideas and therapeutic strategies for the future treatment of spinal cord injury.

CCL2 regulated by the CTBP1-AS2/miR-335-5p axis promotes hemangioma progression and angiogenesis

CONTEXT

Hemangioma (HA) is a benign vascular neoplasm that can lead to permanent scarring. C-C motif chemokine ligand 2 (CCL2) plays a crucial role in facilitating growth and angiogenesis during HA progression. However, the mechanism regulating CCL2 in HA remains poorly elucidated.

OBJECTIVE

To elucidate the mechanism regulating CCL2 in HA.

METHODS

Quantitative real-time polymerase chain reaction (RT-qPCR) was employed to determine the expression levels of CCL2, long noncoding RNA (lncRNA) CTBP1 divergent transcript (CTBP1-AS2), and microRNAs (miRNAs). Proliferation, migration, invasion, and angiogenic abilities of human HA endothelial cells (HemECs) were assessed using cell counting kit-8 (CCK-8), colony formation, flow cytometry, transwell, and tube formation assays. Bioinformatics analysis, RNA pull-down, and luciferase reporter assays were conducted to investigate whether CCL2 targets miR-335-5p. Additionally, rescue experiments were performed in this study.

RESULTS

CCL2 expression was markedly upregulated in HemECs. CCL2 promoted HA cell proliferation, migration, invasion, and angiogenesis while inhibiting apoptosis. CCL2 was directly targeted by miR-335-5p. Additionally, we found that CTBP1-AS2 could function as a competing endogenous RNA (ceRNA) to sponge miR-335-5p, thereby upregulating CCL2.

CONCLUSION

Our findings suggest that targeting the CTBP1-AS2/miR-335-5p/CCL2 axis may hold promise as a therapeutic strategy for HA.

LNC000152 Mediates Aluminum-Induced Proliferation of Reactive Astrocytes

Aluminum is a metal element with significant neurotoxicity, and there is a substantial correlation between aluminum exposure and cognitive dysfunction. Glial fibrillary acidic protein (GFAP) is widely used as a marker of reactive astrocyte proliferation in response to pathological injury of the central nervous system. Studies of various neurodegenerative diseases have confirmed that the expression changes in GFAP are associated with nerve injury. We investigated the role of LNC000152 in the aluminum-induced reactive proliferation of astrocytes. By establishing two aluminum-exposed cell models of rat primary astrocytes and CTX-TNA2 cell lines, we examined the expression of LNC000152 and GFAP and detected cell proliferation with EdU and cell cycle changes with flow cytometry. The role of aluminum in promoting glial cell proliferation was verified; the expression levels of LNC000152 and GFAP increased with the concentration of aluminum exposure. Intervention of LNC000152 expression by siRNA technology revealed that LNC000152 affected glial cell responsive proliferation by influencing GFAP expression. These results suggest that LNC000152 plays a role in the reactive proliferation of astrocytes induced by aluminum.

Prediction of miRNA‑mRNA network regulating the migration ability of cytarabine‑resistant HL60 cells

Cytarabine is an important medicine for acute myeloid leukemia (AML) treatment, however, drug resistance hinders the treatment of AML. Although microRNA (miRNA or miR) alteration is one of the well-recognized mechanisms underlying drug resistance in AML, few studies have investigated the role and function of miRNAs in the development of cytarabine resistance. In the present study, total RNA was isolated from parental HL60 and cytarabine-resistant HL60 (R-HL60) cells. Subsequently, miRNAs and mRNAs were detected using small RNA sequencing and gene expression array, respectively. Differentially expressed mRNAs (DEMs) and differentially expressed genes (DEGs) with more than two-fold changes between HL60 and R-HL60 cells were screened out. Negatively associated miRNA-mRNA pairs were selected as candidate miRNA-mRNA target pairs according to the miRDB, Targetscan or miRTar databases. Functional enrichment analysis of DEGs included in the candidate miRNA-mRNA pairs was performed. The results indicated that 10 DEGs (CCL2, SOX9, SLC8A1, ICAM1, CXCL10, SIPR2, FGFR1, OVOL2, MITF and CARD10) were simultaneously involved in seven Gene Ontology pathways related to the regulation of migration ability, namely the 'regulation of cell migration', 'regulation of locomotion', 'regulation of cellular component movement', 'cell migration', 'locomotion', 'cell motility', and 'localization of cell'. DEMs predicted to negatively regulate the aforementioned 10 DEGs were paired with DEGs into 16 candidate miRNA-mRNA pairs related to the regulation of migration ability. In addition, migration assays revealed that the migration ability of R-HL60 cells was greater than that of HL60 cells. These findings provide a new perspective for the treatment of cytarabine-resistant AML and advance our understanding of altered migration ability underlying cytarabine resistance development, specifically related to miRNAs.

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.

MicroRNA-mediated regulation of reactive astrocytes in central nervous system diseases

Astrocytes (AST) are abundant glial cells in the human brain, accounting for approximately 20-50% percent of mammalian central nervous system (CNS) cells. They display essential functions necessary to sustain the physiological processes of the CNS, including maintaining neuronal structure, forming the blood-brain barrier, coordinating neuronal metabolism, maintaining the extracellular environment, regulating cerebral blood flow, stabilizing intercellular communication, participating in neurotransmitter synthesis, and defending against oxidative stress et al. During the pathological development of brain tumors, stroke, spinal cord injury (SCI), neurodegenerative diseases, and other neurological disorders, astrocytes undergo a series of highly heterogeneous changes, which are called reactive astrocytes, and mediate the corresponding pathophysiological process. However, the pathophysiological mechanisms of reactive astrocytes and their therapeutic relevance remain unclear. The microRNAs (miRNAs) are essential for cell differentiation, proliferation, and survival, which play a crucial role in the pathophysiological development of CNS diseases. In this review, we summarize the regulatory mechanism of miRNAs on reactive astrocytes in CNS diseases, which might provide a theoretical basis for the diagnosis and treatment of CNS diseases.

Research Progress of Long Non-coding RNAs in Spinal Cord Injury

Spinal cord injury (SCI) can result in a partial or complete loss of motor and sensory function below the injured segment, which has a significant impact on patients' quality of life and places a significant social burden on them. Long non-coding RNA (LncRNA) is a 200-1000 bp non-coding RNA that has been shown to have a key regulatory role in the progression of a variety of neurological illnesses. Many studies have demonstrated that differentially expressed LncRNAs following spinal cord injury can participate in inflammatory damage, apoptosis, and nerve healing by functioning as competitive endogenous RNA (ceRNA); at the same time, it has a significant regulatory effect on sequelae such neuropathic pain. As a result, we believe that LncRNAs could be useful as a molecular regulatory target in the diagnosis, treatment, and prognosis of spinal cord injury.

Retinal ganglion cell expression of cytokine enhances occupancy of NG2 cell-derived astrocytes at the nerve injury site: Implication for axon regeneration

Following injury in the central nervous system, a population of astrocytes occupy the lesion site, form glial bridges and facilitate axon regeneration. These astrocytes originate primarily from resident astrocytes or NG2+ oligodendrocyte progenitor cells. However, the extent to which these cell types give rise to the lesion-filling astrocytes, and whether the astrocytes derived from different cell types contribute similarly to optic nerve regeneration remain unclear. Here we examine the distribution of astrocytes and NG2+ cells in an optic nerve crush model. We show that optic nerve astrocytes partially fill the injury site over time after a crush injury. Viral mediated expression of a growth-promoting factor, ciliary neurotrophic factor (CNTF), in retinal ganglion cells (RGCs) promotes axon regeneration without altering the lesion size or the degree of lesion-filling GFAP+ cells. Strikingly, using inducible NG2CreER driver mice, we found that CNTF overexpression in RGCs increases the occupancy of NG2+ cell-derived astrocytes in the optic nerve lesion. An EdU pulse-chase experiment shows that the increase in NG2 cell-derived astrocytes is not due to an increase in cell proliferation. Lastly, we performed RNA-sequencing on the injured optic nerve and reveal that CNTF overexpression in RGCs results in significant changes in the expression of distinct genes, including those that encode chemokines, growth factor receptors, and immune cell modulators. Even though CNTF-induced axon regeneration has long been recognized, this is the first evidence of this procedure affecting glial cell fate at the optic nerve crush site. We discuss possible implication of these results for axon regeneration.

Long non-coding RNA H19 contributes to spinal cord ischemia/reperfusion injury through increasing neuronal pyroptosis by miR-181a-5p/HMGB1 axis

Pyroptosis, a programmed inflammatory necrotizing cell death, is likely involved in spinal cord ischemia-reperfusion (SCI/R) injury, but the mechanisms initiating driving neuronal pyroptosis must be further revealed. The aim of this study is to unravel the mechanism of long non-coding RNA (lncRNA) H19 during SCI/R. SCI/R model was induced in C57BL/6 mice by blocking the aortic arch in vivo, and oxygen-glucose deprivation/reperfusion (OGD/R) injury model of PC12 cells was established in vitro. Our results showed that H19 and HMGB1 expression was upregulated, while miR-181a-5p was downregulated in the SCI/R mice and OGD/R-treated PC12 cells. SCI/R induced pathological damage, pyroptosis and inflammation compared with the sham group. H19 acted as a molecular sponge to suppress miR-181a-5p, and HMGB1 was identified as a direct target of miR-181a-5p. MiR-181a-5p overexpression inhibited the increase of IL-1β, IL-18 and TNF-α production and NLRP3, ASC, and Cleaved-caspase-1 expression in OGD/R-treated PC12 cells; while miR-181a-5p silencing exerted opposite effects. HMGB1 overexpression reversed H19 knockdown-mediated the inhibition of pyroptosis and inflammation in OGD/R-treated PC12 cells. In vivo, H19 knockdown promoted the hind limb motor function recovery and alleviated the pathological damage, pyroptosis and inflammation induced by SCI/R. LncRNA H19/miR-181a-5p/HMGB1 pathway contributes to pyroptosis via activating caspase1 signaling during SCI/R, suggesting that this axis may be a potent therapeutic target in SCI/R.

Circ_0062558 promotes growth, migration, and glutamine metabolism in triple-negative breast cancer by targeting the miR-876-3p/SLC1A5 axis

BACKGROUND

Circular RNAs (circRNAs) have been reported to function as vital regulators in cancers, including triple-negative breast cancer (TNBC). This study aimed to explore the role of circ_0062558 in TNBC.

METHODS

The real-time quantitative polymerase chain reaction (RT-qPCR) was conducted to quantify the expressions of circ_0062558, microRNA-876-3p (miR-876-3p), and solute carrier family 1 (neutral amino acid transporter), member 5 (SLC1A5) in TNBC tissues and cells. 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT), thymidine analog 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, wound healing, and Transwell assays were employed for cell phenotype analyses. Protein expression was tested by western blot analysis. Dual-luciferase reporter was used to confirm the association among circ_0062558, miR-876-3p, and SLC1A5 in TNBC. Xenograft experiments were performed to elucidate the function of circ_0062558 in vivo.

RESULTS

TNBC tissues and cells showed the higher level of circ_0062558 when compared with control samples. Downregulation of circ_0062558 inhibited proliferation, migration, invasion, and glutamine metabolism, while enhanced apoptosis of TNBC cells, and silencing of circ_0062558 also inhibited the growth of tumor in vivo. MiR-876-3p was confirmed as a target of circ_0062558, and circ_0062558 knockdown repressed TNBC cell malignant behaviors by increasing miR-876-3p. Furthermore, miR-876-3p inhibited malignant behaviors of TNBC cells by down-regulating SLC1A5, a newly identified target of miR-876-3p.

CONCLUSION

Circ_0062558 promoted TNBC progression by enhancing proliferation, survival, migration, invasion, and glutamine metabolism via miR-876-3p/SLC1A5 axis, which was helpful for understanding the carcinogenic roles of circ_0062558.

Reactive Astrocytes in Central Nervous System Injury: Subgroup and Potential Therapy

Traumatic central nervous system (CNS) injury, which includes both traumatic brain injury (TBI) and spinal cord injury (SCI), is associated with irreversible loss of neurological function and high medical care costs. Currently, no effective treatment exists to improve the prognosis of patients. Astrocytes comprise the largest population of glial cells in the CNS and, with the advancements in the field of neurology, are increasingly recognized as having key functions in both the brain and the spinal cord. When stimulated by disease or injury, astrocytes become activated and undergo a series of changes, including alterations in gene expression, hypertrophy, the loss of inherent functions, and the acquisition of new ones. Studies have shown that astrocytes are highly heterogeneous with respect to their gene expression profiles, and this heterogeneity accounts for their observed context-dependent phenotypic diversity. In the inured CNS, activated astrocytes play a dual role both as regulators of neuroinflammation and in scar formation. Identifying the subpopulations of reactive astrocytes that exert beneficial or harmful effects will aid in deciphering the pathological mechanisms underlying CNS injuries and ultimately provide a theoretical basis for the development of effective strategies for the treatment of associated conditions. Following CNS injury, as the disease progresses, astrocyte phenotypes undergo continuous changes. Although current research methods do not allow a comprehensive and accurate classification of astrocyte subpopulations in complex pathological contexts, they can nonetheless aid in understanding the roles of astrocytes in disease. In this review, after a brief introduction to the pathology of CNS injury, we summarize current knowledge regarding astrocyte activation following CNS injury, including: (a) the regulatory factors involved in this process; (b) the functions of different astrocyte subgroups based on the existing classification of astrocytes; and (c) attempts at astrocyte-targeted therapy.

Integrated analysis of long non-coding RNA-microRNA-mRNA competing endogenous RNAregulatory networks in thromboangiitis obliterans

Thromboangiitis obliterans (TAO) is a non-atherosclerotic, segmental, chronic vascular inflammatory disease. Our aim was to explore the underlying mechanisms of long non-coding RNA (lncRNA)-related competing endogenous RNAs (ceRNAs) in TAO. Six blood samples were collected from patients with TAO and healthy individuals (three for each category). Total RNA was extracted from the blood of each participant and sequenced. Differentially expressed lncRNAs (DE-lncRNAs) and miRNAs (DE-miRNAs) were screened, and ceRNA networks associated with TAO were constructed. Thereafter, the genes in the ceRNA network were subjected to functional analyses. Finally, a ceRNA relationship (lncRNA NEAT1-hsa-miR-1-3p-mRNA GNA12) was selected for further validation. Analysis revealed that 347 DE-lncRNAs (150 downregulated and 197 upregulated) and 16 DE-miRNAs (3 downregulated and 13 upregulated) were identified in TAO. Further, TAO-associated ceRNA networks, which included 219 lncRNAs, 6 miRNAs, and 53 mRNAs, were proposed and subjected to gene annotation and pathway analysis. Additionally, NEAT1 and GNA12 levels were significantly upregulated, while miR-1-3p levels were evidently downregulated in TAO patients, as compared with those in healthy controls. Dual luciferase reporter assays showed that NEAT1, miR-1-3p, and GNA12 interacted with each other. We report potential TAO-associated ceRNA regulatory networks and suggest activation of NEAT1/miR-1-3p/GNA12 signaling as a novel mechanism for TAO progression.

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.

Exosomes Derived from lncRNA TCTN2-Modified Mesenchymal Stem Cells Improve Spinal Cord Injury by miR-329-3p/IGF1R Axis

Mesenchymal stem cells (MSCs)-derived exosomes play significant roles in alleviating spinal cord injury (SCI). Previous study showed that long non-coding RNA tectonic family member 2 (TCTN2) was able to relieve SCI. Herein, whether TCTN2 exerted its roles in functional recovery after SCI via exosomes derived from MSCs was explored. The SCI model was established in rats, and the neurological function was evaluated using the Basso, Beattie, and Bresnahan (BBB) scoring. Lipopolysaccharide (LPS)-induced differentiated PC12 cells were used as an in vitro model for neurotoxicity research. The expression of genes and proteins was detected by qRT-PCR and Western blot. Exosomes were isolated by ultracentrifugation and qualified by TEM and Western blot. In vitro assays were performed using CCK-8 assay, EdU assay, and flow cytometry, respectively. Dual-luciferase reporter assay and RIP assay were used to confirm the target relationship between miR-329-3p and TCTN2 or insulin-like growth factor1 receptor (IGF1R). TCTN2 expression was down-regulated in SCI model rat and lipopolysaccharide (LPS)-stimulated PC12 cells. MSCs produced exosomes and could package TCTN2 into secreted exosomes. Tail vein injection of TCTN2 exosomes into rats significantly improved functional recovery of SCI. Meanwhile, TCTN2 exosomes treatment alleviated LPS-induced neuronal apoptosis, inflammation, and oxidative stress in vitro. Additionally, TCTN2 targeted miR-329-3p and subsequently regulated the expression of its target IGF1R. Rescue assays suggested that miR-329-3p/IGF1R axis mediated the beneficial effects of TCTN2 exosomes on LPS-treated PC12 cells. In all, exosomes derived from TCTN2-modified MSCs could improve functional recovery of SCI in vivo and attenuate LPS-induced neuronal apoptosis, inflammation, and oxidative stress in vitro via miR-329-3p/IGF1R axis, suggesting a novel insight into the development of MSC-exosomes-based therapy for SCI.

ELK1‑mediated upregulation of lncRNA LBX2‑AS1 facilitates cell proliferation and invasion via regulating miR‑491‑5p/S100A11 axis in colorectal cancer

The aim of the present study was to investigate the role and regulatory mechanism of LBX2 antisense RNA 1 (LBX2-AS1) in colorectal cancer. Firstly, LBX2-AS1 expression was detected using reverse transcription-quantitative PCR in colorectal cancer tissues and cells, and its prognostic and diagnostic efficacy was assessed in a colorectal cancer cohort (n=145). Subcellular fractionation assay of LBX2-AS1 was performed. Secondly, the effects of LBX2-AS1 and microRNA (miR)-491-5p on colorectal cancer cell proliferation, apoptosis, migration and invasion were investigated by a series of functional assays. Thirdly, RNA immunoprecipitation, dual-luciferase reporter and gain and loss of function assays were carried out to analyze the interactions between ETS transcription factor ELK1 (ELK1) and LBX2-AS1, as well as LBX2-AS1, miR-491-5p and S100A11. The results showed that LBX2-AS1 was upregulated both in colorectal cancer tissues and cells, which was distributed in the cytoplasm and nucleus of colorectal cancer cells. Clinically, high LBX2-AS1 expression could be an independent prognostic factor for colorectal cancer. Furthermore, relative operating characteristic curve analysis showed that LBX2-AS1 was a sensitive diagnostic marker for colorectal cancer. Highly expressed ELK1, as a transcription factor, could bind to the two conserved sites in the promoter region of LBX2-AS1, thereby activating the transcription of LBX2-AS1. Silencing LBX2-AS1 markedly inhibited proliferative, migratory and invasive abilities of colorectal cancer cells. miR-491-5p expression was downregulated, while S100A11 expression was upregulated in colorectal cancer tissues and cells. Dual-luciferase reporter assays confirmed that LBX2-AS1 could block S100A11 degradation via competitively binding to miR-491-5p. Furthermore, LBX2-AS1 overexpression could notably reverse the inhibitory effect of miR-491-5p on proliferation and invasion of colorectal cancer cells. Taken together, LBX2-AS1 induced by transcription factor ELK1 may facilitate colorectal cancer cell proliferation and invasion via regulation of the miR-491-5p/S100A11 axis. Thus, LBX2-AS1 could be an underlying prognostic and diagnostic marker for colorectal cancer.

Electroacupuncture promotes the recovery of rats with spinal cord injury by suppressing the Notch signaling pathway via the H19/EZH2 axis

Background

Spinal cord injury (SCI) is a life-changing event with an extremely poor prognosis. In our preliminary studies, electroacupuncture (EA) was found to promote the repair of SCI, which was closely related to the Notch signaling pathway. Therefore, in the present study, we hypothesized that EA protects against SCI by inhibiting the Notch signaling pathway and sought to investigate the underlying molecular mechanisms.

Methods

Rat and cell models of SCI were established. The expression of long non-coding RNA H19 was measured by real-time quantitative polymerase chain reaction. The expression levels of EZH2, Notch1, Notch3, Notch4, Hes1, and PS1 protein were measured by western blot. Cell apoptosis and viability were analyzed using flow cytometry and Cell Counting Kit-8 assays, respectively. The expressions of glial fibrillary acidic protein (GFAP) and nestin were detected by immunofluorescence staining.

Results

The expressions of H19, EZH2, and GFAP were significantly increased after SCI but were inhibited by EA; in contrast, nestin expression was significantly decreased by SCI but was restored by EA. Moreover, oxygen-glucose deprivation (OGD) treatment elevated the expression of H19, EZH2, and Notch-related factors as well as apoptosis in PC-12 cells, while suppressing cell viability. Suppressing H19 alleviated the effects of OGD on cell viability and apoptosis, and inhibited the expression of EZH2 and Notch-related factors expression; these effects were reversed by EZH2 overexpression. Finally, EA promoted the recovery of SCI rats and neural stem cell (NSC) proliferation by inhibiting the Notch signaling pathway, which was reversed by H19 overexpression.

Conclusions

Our results demonstrated that EA promotes the recovery of SCI rats and increases the proliferation and differentiation of NSCs by suppressing the Notch signaling pathway via modulating the H19/EZH2 axis.

The Expanding Regulatory Mechanisms and Cellular Functions of Long Non-coding RNAs (lncRNAs) in Neuroinflammation

LncRNAs have emerged as important regulatory molecules in biological processes. They serve as regulators of gene expression pathways through interactions with proteins, RNA, and DNA. LncRNA expression is altered in several diseases of the central nervous system (CNS), such as neurodegenerative disorders, stroke, trauma, and infection. More recently, it has become clear that lncRNAs contribute to regulating both pro-inflammatory and anti-inflammatory pathways in the CNS. In this review, we discuss the molecular pathways involved in the expression of lncRNAs, their role and mechanism of action during gene regulation, cellular functions, and use of lncRNAs as therapeutic targets during neuroinflammation in CNS disorders.

Inhibition of lncRNA H19/miR-370-3p pathway mitigates neuronal apoptosis in an in vitro model of spinal cord injury (SCI)

BACKGROUND

Spinal cord injury (SCI) is the most serious complication of spinal injury, often leading to severe dysfunction of the limbs below the injured segment. Conventional therapy approaches are becoming less and less effective, and gene therapy is a new research direction by now.

METHODS

The Sprague-Dawley rats were haphazardly assigned to two groups, namely sham group and SCI model group, and lncRNA H19 and miR-370-3p levels were investigated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Correlation between lncRNA H19 and miR-370-3p was ascertained by luciferase report assay and RT-qPCR. After transfection with si-H19, miR-370-3p inhibitor, negative controls (NC), or both, primary spinal neurons were subjected to the simulation of lipopolysaccharide (LPS) for inducing in vitro model of SCI. Cell viability, apoptotic rate, caspase-3 activity, Bax and Bcl-2 protein, ROS generation, TNF-α, IL-1β, and IL-6 protein, as well as IκBα and p65 phosphorylation ratio were evaluated adopting 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), apoptosis, caspase-3 activity, ROS generation, and western blot assays, thereby searching for the specific action mechanism on LPS-induced spinal never injury.

RESULTS

SCI resulted in lncRNA H19 higher expression and miR-370-3p lower expression. LPS simulation raised a series of cellular biological changes, such as decreased viability, promoted apoptosis, generated ROS, and released inflammatory factors. lncRNA H19 inhibition reversed above LPS-induced changes. Besides, as the downstream target of lncRNA H19, miR-370-3p was oppositely regulated by lncRNA H19. The above biological changes induced by lncRNA H19 inhibition were reversed by miR-370-3p upregulation. Moreover, lncRNA H19 inhibition could block NF-κB pathway through miR-370-3p upregulation.

CONCLUSION

Inhibition of lncRNA H19/miR-370-3p mitigated spinal neuron apoptosis in an in vitro model of SCI. This provided the possibility for clinical use of gene therapy.

LncRNA H19 Regulates Lipopolysaccharide (LPS)-Induced Apoptosis and Inflammation of BV2 Microglia Cells Through Targeting miR-325-3p/NEUROD4 Axis

Spinal cord injury (SCI) is a devastating traumatic event worldwide. Work from the past decade has highlighted the key involvement of long non-coding RNAs (lncRNAs) in SCI. Nevertheless, the molecular action of lncRNA H19 in SCI is still not fully understood. The levels of H19, microRNA (miR)-325-3p, and neuronal differentiation 4 (NEUROD4) were determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Flow cytometry was performed to assess cell apoptosis. The levels of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and IL-6 were detected using the enzyme-linked immunosorbent assay (ELISA). Targeted relationships among H19, miR-325-3p, and NEUROD4 were confirmed by dual-luciferase reporter, RNA immunoprecipitation (RIP), or RNA pull-down assays. Our data showed that H19 level was overexpressed in lipopolysaccharide (LPS)-treated BV2 cells. H19 silencing alleviated LPS-evoked cell apoptosis and inflammation. Mechanistically, H19 in BV2 cells directly targeted miR-325-3p, and NEUROD4 was a direct target of miR-325-3p. Moreover, miR-325-3p was a functional target of H19 in regulating cell apoptosis and inflammation induced by LPS. Enforced expression of miR-325-3p relieved LPS-evoked cell apoptosis and inflammation through reducing NEUROD4. Furthermore, H19 in BV2 cells regulated NEUROD4 expression through targeting miR-325-3p. Our results identified that the silencing of H19 attenuated LPS-evoked microglia cell apoptosis and inflammation after SCI at least partially through targeting the miR-325-3p/NEUROD4 axis, highlighting a novel approach for SCI management.