MicroRNA-129-5p inhibits the development of autoimmune encephalomyelitis-related epilepsy by targeting HMGB1 through the TLR4/NF-kB signaling pathway

Pharmacological inhibition of soluble epoxide hydrolase attenuates chronic experimental autoimmune encephalomyelitis by modulating inflammatory and anti-inflammatory pathways in an inflammasome-dependent and -independent manner

We aimed to determine the effect of soluble epoxide hydrolase (sEH) inhibition on chronic experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS), associated with changes in inflammasome-dependent and -independent inflammatory and anti-inflammatory pathways in the CNS of mice. C57BL/6 mice were used to induce chronic EAE by using an injection of MOG_35-55 peptide/PT. Animals were observed daily and scored for EAE signs for 25 days after immunization. Following the induction of EAE, the scores were increased after 9 days and reached peak value as determined by ≥ 2 or ≤ 3 with 8% mortality rate on day 17. On day 17, mice were administered daily PBS, DMSO, or TPPU (a potent sEH inhibitor) (1, 3, or 10 mg/kg) until the end of the study. TPPU only at 3 mg/kg dose decreased the AUC values calculated from EAE scores obtained during the disease compared to EAE and vehicle control groups. On day 25, TPPU also caused an increase in the PPARα/β/γ and NLRC3 proteins and a decrease in the proteins of TLR4, MyD88, NF-κB p65, p-NF-κB p65, iNOS/nNOS, COX-2, NLRC4, ASC, caspase-1 p20, IL-1β, caspase-11 p20, NOX subunits (gp91^phox and p47^phox), and nitrotyrosine in addition to 14,15-DHET and IL-1β levels compared to EAE and vehicle control groups. Our findings suggest that pharmacological inhibition of sEH attenuates chronic EAE likely because of enhanced levels of anti-inflammatory EETs in addition to PPARα/β/γ and NLRC3 expression associated with suppressed inflammatory TLR4/MyD88/NF-κB signalling pathway, NLRC4/ASC/pro-caspase-1 inflammasome, caspase-11 inflammasome, and NOX activity that are responsible for inflammatory mediator formation in the CNS of mice.

Silencing lncRNA AGAP2-AS1 Upregulates miR-195-5p to Repress Migration and Invasion of EC Cells via the Decrease of FOSL1 Expression

The interaction of long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs has been implicated in various types of cancers, including esophageal cancer (EC). The current study aimed to investigate the role of AGAP2-AS1/miR-195-5p/Fos-like antigen-1 (FOSL1) in EC progression. The expression of AGAP2-AS1, miR-195-5p, and FOSL1 in tumor tissues isolated from EC patients and EC cell lines was determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), the results of which illustrated that AGAP2-AS1 and FOSL1 were increased while miR-195-5p was reduced in EC. Next, the ectopic expression, knockdown, and reporter assay experiments were all employed to elucidate the mechanism of AGAP2-AS1/miR-195-5p/FOSL1 in the processes of EC cell proliferation, cell cycle, apoptosis, invasion, and migration as well as tumor growth. Knockdown of AGAP2-AS1 or overexpression of miR-195-5p reduced EC cell proliferation, migration, and invasion, blocked cell cycle entry, and elevated apoptosis. FOSL1 was found to be specifically targeted by miR-195-5p. AGAP2-AS1 was observed to upregulate FOSL1 by binding to miR-195-5p. Silencing of AGAP2-AS1 was observed to restrain the development of EC both in vitro and in vivo through upregulating miR-195-5p and downregulating FOSL1. Taken together, AGAP2-AS1 knockdown exercises suppressive effects on the development of EC through miR-195-5p-dependent downregulation of FOSL1. Therefore, targeting AGAP2-AS1 could be a future direction to develop a novel molecule-targeted therapeutic strategy for EC.

Role of Nuclear Factor Kappa B (NF-κB) Signalling in Neurodegenerative Diseases: An Mechanistic Approach

A transcriptional regulatory nuclear factor kappa B (NF-κB) protein is a modulator of cellular biological activity via binding to a promoter region in the nucleus and transcribing various protein genes. The recent research implicated the intensive role of nuclear factor kappa B (NF-κB) in diseases like autoimmune disorder, inflammatory, cardiovascular and neurodegenerative diseases. Therefore, targeting the nuclear factor kappa B (NF-κB) protein offers a new opportunity as a therapeutic approach. Activation of IκB kinase/NF-κB signaling pathway leads to the development of various pathological conditions in human beings, such as neurodegenerative, inflammatory disorders, autoimmune diseases, and cancer. Therefore, the transcriptional activity of IκB kinase/NF- κB is strongly regulated at various cascade pathways. The nuclear factor NF-kB pathway plays a major role in the expression of pro-inflammatory genes, including cytokines, chemokines, and adhesion molecules. In response to the diverse stimuli, the cytosolic sequestered NF-κB in an inactivated form by binding with an inhibitor molecule protein (IkB) gets phosphorylated and translocated into the nucleus further transcribing various genes necessary for modifying various cellular functions. The various researches confirmed the role of different family member proteins of NF-κB implicated in expressing various genes products and mediating various cellular cascades. MicroRNAs, as regulators of NF- κB microRNAs play important roles in the regulation of the inflammatory process. Therefore, the inhibitor of NF-κB and its family members plays a novel therapeutic target in preventing various diseases. Regulation of NF- κB signaling pathway may be a safe and effective treatment strategy for various disorders.

miR-300 mitigates cancer-induced bone pain through targeting HMGB1 in rat models

BACKGROUND

Cancer-induced bone pain (CIBP) is the pain caused by bone metastasis from malignant tumors, and the largest source of pain for cancer patients. miR-300 is an important miRNA in cancer. It has been shown that miR-300 regulates tumorigenesis of various tumors.

OBJECTIVE

This study aims to investigate the role of miR-300 in CIBP and its underlying molecular mechanisms in vitro and in vivo.

METHODS

We constructed CIBP model in rats and investigated the mechanism through which miR-300 affects CIBP. We first examined expression level of miR-300 in CIBP rats and then tested the effect of its overexpression. Next, we identified the target of miR-300 using TargetScan analysis and double luciferase assay. Finally, we studied genetic interactions between miR-300 and its target and their roles in CIBP.

RESULTS

We found that miR-300 was downregulated in CIBP rats. Overexpression of miR-300 significantly attenuated cancer-induced neuropathic pain (p < 0.01). Furthermore, TargetScan analysis and double luciferase assay show High Mobility Group Box 1 (HMGB1) is a target of miR-300. Notably, HMGB1 is overexpressed in CIBP rats, while up-regulation of miR-300 significantly suppresses expression of HMGB1 (p < 0.01). Moreover, knockdown of HMGB1 by siRNA significantly relieves cancer-induced neuropathic pain in rats (p < 0.01). On the other hand, HMGB1 overexpression partially blocked the effect of miR-300 on cancer-induced nerve pain.

CONCLUSION

miR-300 relieves cancer-induced neuropathic pain by inhibiting HMGB1 expression. These results may be beneficial for the treatment of CIBP in clinical practice.

Identifying the culprits in neurological autoimmune diseases

The target organ of neurological autoimmune diseases (NADs) is the central or peripheral nervous system. Multiple sclerosis (MS) is the most common NAD, whereas Guillain-Barré syndrome (GBS), myasthenia gravis (MG), and neuromyelitis optica (NMO) are less common NADs, but the incidence of these diseases has increased exponentially in the last few years. The identification of a specific culprit in NADs is challenging since a myriad of triggering factors interplay with each other to cause an autoimmune response. Among the factors that have been associated with NADs are genetic susceptibility, epigenetic mechanisms, and environmental factors such as infection, microbiota, vitamins, etc. This review focuses on the most studied culprits as well as the mechanisms used by these to trigger NADs.

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Neurological autoimmune diseases are caused by a complex interaction between genes, environmental factors, and epigenetic deregulation.

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Infectious agents can cause an autoimmune reaction to myelin epitopes through molecular mimicry and/or bystander activation.

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Gut microbiota dysbiosis contributes to neurological autoimmune diseases.

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Smoking increases the risk of NADs through inflammatory signaling pathways, oxidative stress, and Th17 differentiation.

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Deficiency in vitamin D favors NAD development through direct damage to the central and peripheral nervous system.

Advances in the Potential Biomarkers of Epilepsy

Epilepsy is a group of chronic neurological disorders characterized by recurrent, spontaneous, and unpredictable seizures. It is one of the most common neurological disorders, affecting tens of millions of people worldwide. Comprehensive studies on epilepsy in recent decades have revealed the complexity of epileptogenesis, in which immunological processes, epigenetic modifications, and structural changes in neuronal tissues have been identified as playing a crucial role. This review discusses the recent advances in the biomarkers of epilepsy. We evaluate the possible molecular background underlying the clinical changes observed in recent studies, focusing on therapeutic investigations, and the evidence of their safety and efficacy in the human population. This article reviews the pathophysiology of epilepsy, including recent reports on the effects of oxidative stress and hypoxia, and focuses on specific biomarkers and their clinical implications, along with further perspectives in epilepsy research.

HMGB1: A Common Biomarker and Potential Target for TBI, Neuroinflammation, Epilepsy, and Cognitive Dysfunction

High mobility group box protein 1 (HMGB1) is a ubiquitous nuclear protein released by glia and neurons upon inflammasome activation and activates receptor for advanced glycation end products (RAGE) and toll-like receptor (TLR) 4 on the target cells. HMGB1/TLR4 axis is a key initiator of neuroinflammation. In recent days, more attention has been paid to HMGB1 due to its contribution in traumatic brain injury (TBI), neuroinflammatory conditions, epileptogenesis, and cognitive impairments and has emerged as a novel target for those conditions. Nevertheless, HMGB1 has not been portrayed as a common prognostic biomarker for these HMGB1 mediated pathologies. The current review discusses the contribution of HMGB1/TLR4/RAGE signaling in several brain injury, neuroinflammation mediated disorders, epileptogenesis and cognitive dysfunctions and in the light of available evidence, argued the possibilities of HMGB1 as a common viable biomarker of the above mentioned neurological dysfunctions. Furthermore, the review also addresses the result of preclinical studies focused on HMGB1 targeted therapy by the HMGB1 antagonist in several ranges of HMGB1 mediated conditions and noted an encouraging result. These findings suggest HMGB1 as a potential candidate to be a common biomarker of TBI, neuroinflammation, epileptogenesis, and cognitive dysfunctions which can be used for early prediction and progression of those neurological diseases. Future study should explore toward the translational implication of HMGB1 which can open the windows of opportunities for the development of innovative therapeutics that could prevent several associated HMGB1 mediated pathologies discussed herein.

Combined gemfibrozil (peroxisome proliferator-activated receptor alpha agonist) with reduced steroid dose gives a similar management picture as the full steroid dose in a rat adjuvant-induced arthritis model

Objectives: The study aimed to evaluate the efficacy of combined gemfibrozil with prednisolone in the management of adjuvant-induced arthritis (AIA) rat model. Methods: Seventy two adult male Wistar albino rats were divided equally into 1-control group, three diseased groups: 2- Adjuvant induced arthritis (AIA), 3- high fat diet (HF), and 4- combined AIA-HF, and treated groups: 5- gemfibrozil 30 mg/kg treated AIA group (AIA-G) and the combined AIA-HF treated groups: 6- prednisolone equivalent to human 10 mg (AIA-HF-P10), 7- prednisolone equivalent to human 5 mg (AIA-HF-P5) 8- gemfibrozil (HF-AIA-G) and 9- combined treatment (HF-AIA-G-P5) Results: HF diet represents a precipitating factor for knee arthritis. Gemfibrozil improved the inflammatory findings in both AIA and AIA-HF groups. Combined administration of gemfibrozil with reduced steroid dose gave a similar therapeutic effect to the full steroid dose. Fortunately, we reported more reduction in the nuclear factor kappa-B (NF-κB) and high mobility group box 1 (HMGB1) in the HF-AIA-G-P5 compared with the HF-AIA-P10 group. The improvement was proved by the histological findings. Conclusion: Combined reduced prednisolone dose with gemfibrozil potentiates its anti-inflammatory activity. This could be a target in the management of rheumatoid arthritis.

MicroRNA-421 suppresses the apoptosis and autophagy of hippocampal neurons in epilepsy mice model by inhibition of the TLR/MYD88 pathway

Epilepsy is a group of neurological disorders characterized by epileptic seizures. In this study, we aim to explore the role of microRNA-421 (miR-421) in hippocampal neurons of epilepsy mice via the TLR/MYD88 pathway. Forty mice were randomly served as the normal and model (established as epilepsy model) groups. Hippocampal neurons were assigned into seven groups with different transfections. The RT-qPCR and western blotting were conducted to examine the expression of miR-421 TLR2, TLR4, MYD88, Bax, Bcl-2, p53, Beclin-1, and LC3II/LC3I. Cell proliferation and apoptosis were detected by MTT and flow cytometry.MYD88 is a target gene of miR-421. Model mice showed elevated expression of TLR2, TLR4, MYD88, Bax, p53, Beclin-1, and LC3II/LC3I but reduced expression of miR-421 and Bcl-2. In vitro experiments reveals that overexpression of miR-421 inhibited the TLR/MYD88 pathway. Besides, overexpressed miR-421 declined cell apoptosis but increased cell proliferation. It reveals that miR-421 targeting MYD88 could inhibit the apoptosis and autophagy of hippocampal neurons in epilepsy mice by down-regulating the TLR/MYD88 pathway.

Elevated microRNA-129-5p level ameliorates neuroinflammation and blood-spinal cord barrier damage after ischemia-reperfusion by inhibiting HMGB1 and the TLR3-cytokine pathway

Background

Ischemia-reperfusion (IR) affects microRNA (miR) expression and causes substantial inflammation. Multiple roles of the tumor suppressor miR-129-5p in cerebral IR have recently been reported, but its functions in the spinal cord are unclear. Here, we investigated the role of miR-129-5p after spinal cord IR, particularly in regulating high-mobility group box-1 (HMGB1) and the Toll-like receptor (TLR)-3 pathway.

Methods

Ischemia was induced via 5-min occlusion of the aortic arch. The relationship between miR-129-5p and HMGB1 was elucidated via RT-PCR, western blotting, and luciferase assays. The cellular distribution of HMGB1 was determined via double immunofluorescence. The effect of miR-129-5p on the expression of HMGB1, TLR3, and downstream cytokines was evaluated using synthetic miRs, rHMGB1, and the TLR3 agonist Poly(I:C). Blood-spinal cord barrier (BSCB) permeability was examined by measuring Evans blue (EB) dye extravasation and the water content.

Results

The temporal miR-129-5p and HMGB1 expression profiles and luciferase assay results indicated that miR-129-5p targeted HMGB1. Compared with the Sham group, the IR group had higher HMGB1 immunoreactivity, which was primarily distributed in neurons and microglia. Intrathecal injection of the miR-129-5p mimic significantly decreased the HMGB1, TLR3, interleukin (IL)-1β and tumor necrosis factor (TNF)-α levels and the double-labeled cell count 48 h post-surgery, whereas rHMGB1 and Poly(I:C) reversed these effects. Injection of miR-129-5p mimic preserved motor function and prevented BSCB leakage based on increased Basso Mouse Scale scores and decreased EB extravasation and water content, whereas injection rHMGB1 and Poly(I:C) aggravated these injuries.

Conclusions

Increasing miR-129-5p levels protect against IR by ameliorating inflammation-induced neuronal and BCSB damage by inhibiting HMGB1 and TLR3-associated cytokines.