MicroRNA-365 Knockdown Prevents Ischemic Neuronal Injury by Activating Oxidation Resistance 1-Mediated Antioxidant Signals

Baicalein ameliorates oxidative stress and brain injury after intracerebral hemorrhage by activating the Nrf2/ARE pathway via miR-106a-5p/PHLPP2 axis

Intracerebral hemorrhage (ICH) is a devastating stroke subtype. Baicalein (BAI) has been reported to be effective in ischemic stroke. The aim of the present study was to investigate the mechanism of BAI on brain injury after ICH. Firstly, ICH mouse models were established by injecting collagenase into the right of basal ganglia, followed by detection of neurobehavioral scores, brain edema, oxidative stress (OS) level, neuronal apoptosis and pathological changes. Average neurologic scores, brain water content, and blood-brain barrier permeability and MDA level in ICH mice were reduced after BAI treatment, while serum SOD and GSH-Px levels were increased and neuronal apoptosis and pathological injury of the brain tissues were mitigated. miR-106a-5p downregulation averted the effect of BAI on ICH mice. miR-106a-5p targeted PHLPP2 and PHLPP2 overexpression reversed the effect of BAI on ICH mice. BAI activated the Nrf2/ARE pathway by inhibiting PHLPP2 expression. In conclusion, BAI inhibited OS and protected against brain injury after ICH by activating the Nrf2/ARE pathway through the miR-106a-5p/PHLPP2 axis.

Association between miR-365 polymorphism and ischemic stroke in a Chinese population

Background

Ischemic stroke (IS) represents a major cause of morbidity and mortality across the globe. The aberrant expression of miR-365 has been found to be implicated in a wide array of human diseases, including atherosclerosis and cancer. Studies on single-nucleotide polymorphisms (SNPs) in miRNA genes can help gain insight into the susceptibility to the condition. This study aimed to examine the relationship between miR-365 SNPs and the risk of IS.

Methods

The study recruited 215 IS patients and 220 controls. The SNPscans genotyping was employed to genotype three polymorphic loci (rs121224, rs30230, and rs178553) of miR-365. The relative expression of miR-365 in peripheral blood mononuclear cells of the patients and controls was determined by using real-time quantitative PCR.

Results

The miR-365 rs30230 polymorphism exhibited a significant association with the risk of developing IS (TC vs. CC: adjusted OR = 0.55, 95% CI: 0.33-0.92, P = 0.022; TT vs. CC: adjusted OR = 0.34, 95% CI: 0.14-0.85, P = 0.021; TC +TT vs. CC: adjusted OR = 0.51, 95% CI: 0.31-0.83, P = 0.007; T vs. C: adjusted OR = 0.57, 95% CI: 0.39-0.83, P = 0.004). Haplotype analysis revealed that the C-T-G haplotype was associated with a decreased risk of IS (OR = 0.68, 95% CI: 0.46-1.00, P = 0.047). Furthermore, miR-365 expression was significantly higher in IS patients than in controls (P < 0.001). Interestingly, patients with rs30230 TC or TT genotypes had lower miR-365 levels compared to their counterparts with CC genotypes (P < 0.001).

Conclusions

The miR-365 rs30230 polymorphism might bear an association with IS susceptibility in the Chinese population, and the rs30230 TC/TT genotype might be a protective factor against IS.

Multi-pathway neuroprotective effects of a novel salidroside derivative SHPL-49 against acute cerebral ischemic injury

SHPL-49 ((2R,3S,4S,5R,6R)-2-(hydroxymethyl)-6-(4-(4-methoxyphenyl) butoxy) tetrahydro-2H-pyran-3,4,5-triol) is a novel glycoside derivative obtained from structural modification of salidroside, which is isolated from the medicinal plant Rhodiola rosea L. SHPL-49 was administered to rats with permanent middle cerebral artery occlusion (pMCAO) for 5 days, and it was found that SHPL-49 could alleviate the cerebral infarct volume and reduce the neurological deficit score. Moreover, the effective time window of SHPL-49 in the pMCAO model was from 0.5 to 8 h after embolization. In addition, the result of immunohistochemistry showed that SHPL-49 could increase the number of neurons in the brain tissue and reduce the occurrence of apoptosis. Morris water maze and Rota-rod experiments showed that SHPL-49 could improve neurological deficits, repair neurocognitive and motor dysfunction, and enhance learning and memory ability in the pMCAO model after 14 days of SHPL-49 treatment. Further in vitro experiments showed that SHPL-49 significantly reduced the calcium overload of PC-12 cells and the production of reactive oxygen species (ROS) induced by oxygen and glucose deprivation (OGD), and increased the levels of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), decreased the production of malondialdehyde (MDA). Furthermore, SHPL-49 could reduce cell apoptosis by increasing protein expression ratio of anti-apoptotic factor Bcl-2 to pro-apoptotic factor Bax in vitro. SHPL-49 also regulated the expression of Bcl-2 and Bax in ischemic brain tissue, and even inhibited the caspase cascade of pro-apoptotic proteins Cleaved-caspase 9 and Cleaved-caspase 3. Taken together, SHPL-49 exhibited neuroprotective effects against cerebral ischemic injury through multiple pathways, such as alleviating calcium overload, reducing oxidative stress damage, and inhibiting apoptosis.

Exercise pretreatment alleviates neuroinflammation and oxidative stress by TFEB-mediated autophagic flux in mice with ischemic stroke

BACKGROUND

Neuroinflammation and oxidative stress are important pathological mechanisms underlying cerebral ischemic stroke. Increasing evidence suggests that regulation autophagy in ischemic stroke may improve neurological functions. In this study, we aimed to explore whether exercise pretreatment attenuates neuroinflammation and oxidative stress in ischemic stroke by improving autophagic flux.

METHODS

2,3,5-Triphenyltetrazolium chloride staining was used to determine the infarction volume, and modified Neurological Severity Scores and rotarod test were used to evaluate neurological functions after ischemic stroke. The levels of oxidative stress, neuroinflammation, neuronal apoptosis and degradation, autophagic flux, and signaling pathway proteins were determined using immunofluorescence, dihydroethidium, TUNEL, and Fluoro-Jade B staining, western blotting, and co-immunoprecipitation.

RESULTS

Our results showed that, in middle cerebral artery occlusion (MCAO) mice, exercise pretreatment improved neurological functions and defective autophagy, and reduced neuroinflammation and oxidative stress. Mechanistically, after using chloroquine, impaired autophagy abolished the neuroprotection of exercise pretreatment. And transcription factor EB (TFEB) activation mediated by exercise pretreatment contributes to improving autophagic flux after MCAO. Furthermore, we showed that TFEB activation mediated by exercise pretreatment in MCAO was regulated by the AMPK-mTOR and AMPK-FOXO3a-SKP2-CARM1 signaling pathways.

CONCLUSIONS

Exercise pretreatment has the potential to improve the prognosis of ischemic stroke patients, and it can exert neuroprotective effects in ischemic stroke by inhibiting neuroinflammation and oxidative stress, which might be due to the TFEB-mediated autophagic flux. And targeting autophagic flux may be promising strategies for the treatment of ischemic stroke.

Lacticaseibacillus casei T1 attenuates Helicobacter pylori-induced inflammation and gut microbiota disorders in mice

Probiotics are defined as live microbial food elements that are beneficial to human health. Lacticaseibacillus casei T1 was considered to have potential as a bioactive ingredient in functional foods, which was isolated from kurut. Previous research by our group proved that L. casei T1 could prevent inflammatory responses caused by Helicobacter pylori. This study aimed to investigate whether treatment with L. casei T1 resulted in a suppressive effect on H. pylori-induced oxidative stress and inflammatory responses. The results showed that treatment with L. casei T1 could relieve H. pylori-induced overexpression of inflammatory cytokines in GES-1 cells. Experiments in animals suggested that taking long-term L. casei T1 could reduce oxidative stress and inflammatory cytokines and improve H. pylori-induced gastric mucosal damage. Furthermore, taking L. casei T1 could increase the relative abundance of beneficial intestinal bacterium (Lachnospiraceae and Odoribacter) of H. pylori-infected mice and help in maintaining the balance of intestinal microflora.Collectively, L. casei T1 had certain degrees of therapeutic effect against H. pylori. In the future, it combined with antibiotics for H. pylori eradication deserves further study.

Neuroprotective Effect of Angiopoietin2 Is Associated with Angiogenesis in Mouse Brain Following Ischemic Stroke

Angiogenic factors play an important role in protecting, repairing, and reconstructing vessels after ischemic stroke. In the brains of transient focal cerebral ischemic mice, we observed a reduction in infarct volume after the administration of Angiopoietin 2 (Angpt2), but whether this process is promoted by Angpt2-induced angiogenesis has not been fully elaborated. Therefore, this study explored the angiogenic activities, in reference to CD34 which is a marker of activated ECs and blood vessels, of cultured ECs in vitro and in ischemic damaged cerebral area in mice following Angpt2 administration. Our results demonstrate that Angpt2 administration (100 ng/mL) is neuroprotective by significantly increasing the CD34 expression in in vitro-cultured ECs, reducing the infarct volume and mitigating neuronal loss, as well as enhancing CD34⁺ vascular length and area. In conclusion, these results indicate that Angpt2 promotes repair and attenuates ischemic injury, and that the mechanism of this is closely associated with angiogenesis in the brain after stroke.

CORM-3 Attenuates Oxidative Stress-Induced Bone Loss via the Nrf2/HO-1 Pathway

Bone metabolism occurs in the entire life of an individual and is required for maintaining skeletal homeostasis. The imbalance between osteogenesis and osteoclastogenesis eventually leads to osteoporosis. Oxidative stress is considered a major cause of bone homeostasis disorder, and relieving excessive oxidative stress in bone mesenchymal stem cells (BMSCs) is a potential treatment strategy for osteoporosis. Carbon monoxide releasing molecule-3 (CORM-3), the classical donor of carbon monoxide (CO), possesses antioxidation, antiapoptosis, and anti-inflammatory properties. In our study, we found that CORM-3 could reduce reactive oxygen species (ROS) accumulation and prevent mitochondrial dysfunction thereby restoring the osteogenic potential of the BMSCs disrupted by hydrogen peroxide (H₂O₂) exposure. The action of CORM-3 was preliminarily considered the consequence of Nrf2/HO-1 axis activation. In addition, CORM-3 inhibited osteoclast formation in mouse primary bone marrow monocytes (BMMs) by inhibiting H₂O₂-induced polarization of M1 macrophages and endowing macrophages with M2 polarizating ability. Rat models further demonstrated that CORM-3 treatment could restore bone mass and enhance the expression of Nrf2 and osteogenic markers in the distal femurs. In summary, CORM-3 is a potential therapeutic agent for the treatment of osteoporosis.

Oxidative Stress Resistance 1 Gene Therapy Retards Neurodegeneration in the rd1 Mutant Mouse Model of Retinopathy

Purpose

Oxidative stress is a major factor underlying many neurodegenerative diseases. However, antioxidant therapy has had mixed results, possibly because of its indiscriminate activity. The purpose of our study was to determine if the human OXR1 (hOXR1) antioxidant regulatory gene could protect neurons from oxidative stress and delay photoreceptor cell death.

Methods

The cone-like 661W cell line was transfected to stably express the hOXR1 gene. Oxidative stress was induced by the addition of hydrogen peroxide (H2O2). Intracellular levels of reactive oxygen species (ROS), caspase cleavage, and cellular resistance to oxidative stress were determined and compared between the control and hOXR1 cells. For in vivo analysis, AAV8-hOXR1 was injected subretinally into the rd1 mouse model of retinal degeneration. Functional and structural integrity of the photoreceptors were assessed using electroretinography (ERG), histology, and immunofluorescence analysis.

Results

Expression of hOXR1 increased cellular resistance and reduced ROS levels and caspase cleavage in the 661W cell line after H2O2-induced oxidative stress. Subretinal injection of AAV8-hOXR1 in the rd1 mice improved their photoreceptor light response, expression and localization of photoreceptor-specific proteins, and delayed retinal degeneration.

Conclusions

Our results suggest that OXR1 is a potential therapy candidate for retinal degeneration. Because OXR1 targets oxidative stress, a common feature of many retinal degenerative diseases, it should be of therapeutic value to multiple retinal degenerative diseases.

MicroRNAs Involved in Oxidative Stress Processes Regulating Physiological and Pathological Responses

Oxidative stress influences several physiological and pathological cellular events, including cell differentiation, excessive growth, proliferation, apoptosis, and the inflammatory response. Therefore, oxidative stress is involved in the pathogenesis of various diseases, including pulmonary fibrosis, epilepsy, hypertension, atherosclerosis, Parkinson's disease, cardiovascular disease, and Alzheimer's disease. Recent studies have shown that several microRNAs (miRNAs) are involved in developing various diseases caused by oxidative stress and that miRNAs may be helpful to determine the inflammatory characteristics of immune responses during infection and disease. This review describes the known effects of miRNAs on reactive oxygen species to induce oxidative stress and the miRNA regulatory mechanisms involved in the uncoupling of Keap1-Nrf2 complexes. Finally, we summarized the functions of miRNAs in several antioxidant genes. Understanding the crosstalk between miRNAs and oxidative stress-inducing factors during physiological and pathological cellular events may have implications for designing more effective treatments for immune diseases.

Neurovascular Unit: A critical role in ischemic stroke

Ischemic stroke (IS), a common cerebrovascular disease, results from a sudden blockage of a blood vessel in the brain, thereby restricting blood supply to the area in question, and making a significantly negative impact on human health. Unfortunately, current treatments, that are mainly based on a recanalization of occluded blood vessels, are insufficient or inaccessible to many stroke patients. Recently, the profound influence of the neurovascular unit (NVU) on recanalization and the prognosis of IS have become better understood; in‐depth studies of the NVU have also provided novel approaches for IS treatment. In this article, we review the intimate connections between the changes in the NVU and IS outcomes, and discuss possible new management strategies having practical significance to IS. We discuss the concept of the NVU, as well as its roles in IS blood‐brain barrier regulation, cell preservation, inflammatory immune response, and neurovascular repair. Besides, we also summarize the influence of noncoding RNAs in NVU, and IS therapies targeting the NVU. We conclude that both the pathophysiological and neurovascular repair processes of IS are strongly associated with the homeostatic state of the NVU and that further research into therapies directed at the NVU could expand the range of treatments available for IS.

Preventing Neurodegeneration by Controlling Oxidative Stress: The Role of OXR1

Parkinson’s disease, diabetic retinopathy, hyperoxia induced retinopathy, and neuronal damage resulting from ischemia are among the notable neurodegenerative diseases in which oxidative stress occurs shortly before the onset of neurodegeneration. A shared feature of these diseases is the depletion of OXR1 (oxidation resistance 1) gene products shortly before the onset of neurodegeneration. In animal models of these diseases, restoration of OXR1 has been shown to reduce or eliminate the deleterious effects of oxidative stress induced cell death, delay the onset of symptoms, and reduce overall severity. Moreover, increasing OXR1 expression in cells further increases oxidative stress resistance and delays onset of disease while showing no detectable side effects. Thus, restoring or increasing OXR1 function shows promise as a therapeutic for multiple neurodegenerative diseases. This review examines the role of OXR1 in oxidative stress resistance and its impact on neurodegenerative diseases. We describe the potential of OXR1 as a therapeutic in light of our current understanding of its function at the cellular and molecular level and propose a possible cascade of molecular events linked to OXR1’s regulatory functions.

Decreased MiR-485-5p Contributes to Inflammatory Pain Through Post-Transcriptional Upregulation of ASIC1 in Rat Dorsal Root Ganglion

Background

Inflammatory pain is the most common type of pain treated clinically. However, the currently available treatments for inflammatory pain have limited effects and can cause severe side effects. The aim of this study is to describe the effect of miRNA-485-5p on osteoarthritis-related inflammatory pain.

Methods

Paw withdrawal threshold (PWT) of rats was measured by von Frey filaments. The expressions of miRNA-485-5p and acid-sensing ion channel 1 (ASIC1) in the dorsal root ganglion (DRG) were measured with real-time quantitative PCR and Western blotting analysis. Fluorescent in situ hybridization and fluorescent immunohistochemistry were employed to detect expression of miRNA-485-5p, acid-sensing ion channelASIC1 and co-location of miRNA-485-5p with ASIC1.

Results

The PWT of rats was significantly reduced after complete Freund's adjuvant (CFA) injection. The miRNA-485-5p expression level clearly decreased while the ASIC1 expression level was upregulated in the L4-6 dorsal root ganglion (DRG) of CFA rats. MiRNA-485-5p and ASIC1 were co-expressed in the same DRG cells of CFA rats. Amiloride, an inhibitor of ASIC1, clearly increased the PWT of CFA rats. Further, miRNA-485-5p agomir reversed the upregulation of ASICI1 and alleviated CFA-induced mechanical hypersensitivity of CFA rats.

Conclusion

These results suggest that reduced expression of miRNA-485-5p contributes to inflammatory pain through upregulating ASIC1 expression, implying a promising strategy for pain therapy.

MiR-125a-5p Regulates Vitamin D Receptor Expression in a Mouse Model of Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is a chronic and incurable autoimmune neurodegenerative disease of the central nervous system. Although the symptoms of MS can be managed by vitamin D3 treatment alone, this condition cannot be completely eradicated. Thus, there might be unknown factors capable of regulating the vitamin D receptor (VDR). Genome-wide analysis showed that miRNAs were associated with VDRs. We sought to determine the role and mechanism of action of miRNA-125a-5p and VDRs in a model of MS, mice with experimental autoimmune encephalomyelitis (EAE), which was induced by myelin oligodendrocyte glycoprotein 35-55 peptides. EAE mice showed decreased mean body weight but increased mean clinical scores compared with vehicle or control mice. And inflammatory infiltration was found in the lumbosacral spinal cord of EAE mice. In addition, VDR expression was significantly lower while the expression of miR-125a-5p was markedly higher in the spinal ventral horn of EAE mice than in vehicle or control mice. Importantly, activation of VDRs by paricalcitol or inhibition of miR-125a-5p by its antagomir markedly decreased the mean clinical scores in EAE mice. Interestingly, VDR and miR-125a-5p were co-localized in the same neurons of the ventral horn. More importantly, inhibition of miR-125a-5p remarkably blocked the decrease of VDRs in EAE mice. These results support a critical role for miR-125a-5p in modulating VDR activity in EAE and suggest potential novel therapeutic interventions.