MicroRNA-193b-3p alleviates focal cerebral ischemia and reperfusion-induced injury in rats by inhibiting 5-lipoxygenase expression

miR-193b-3p and miR-346 Exert Antihypertensive Effects in the Rostral Ventrolateral Medulla

BACKGROUND

Rostral ventrolateral medulla (RVLM) neuron hyperactivity raises sympathetic outflow, causing hypertension. MicroRNAs (miRNAs) contribute to diverse biological processes, but their influence on RVLM neuronal excitability and blood pressure (BP) remains widely unexplored.

METHODS AND RESULTS

The RVLM miRNA profiles in spontaneously hypertensive rats were unveiled using RNA sequencing. Potential effects of these miRNAs in reducing neuronal excitability and BP and underlying mechanisms were investigated through various experiments. Six hundred thirty-seven miRNAs were identified, and reduced levels of miR-193b-3p and miR-346 were observed in the RVLM of spontaneously hypertensive rats. Increased miR-193b-3p and miR-346 expression in RVLM lowered neuronal excitability, sympathetic outflow, and BP in spontaneously hypertensive rats. In contrast, suppressing miR-193b-3p and miR-346 expression in RVLM increased neuronal excitability, sympathetic outflow, and BP in Wistar Kyoto and Sprague-Dawley rats. Cdc42 guanine nucleotide exchange factor (Arhgef9) was recognized as a target of miR-193b-3p. Overexpressing miR-193b-3p caused an evident decrease in Arhgef9 expression, resulting in the inhibition of neuronal apoptosis. By contrast, its downregulation produced the opposite effects. Importantly, the decrease in neuronal excitability, sympathetic outflow, and BP observed in spontaneously hypertensive rats due to miR-193b-3p overexpression was greatly counteracted by Arhgef9 upregulation.

CONCLUSIONS

miR-193b-3p and miR-346 are newly identified factors in RVLM that hinder hypertension progression, and the miR-193b-3p/Arhgef9/apoptosis pathway presents a potential mechanism, highlighting the potential of targeting miRNAs for hypertension prevention.

BMSC-Exosomes attenuate ALP dysfunction by restoring lysosomal function via the mTOR/TFEB Axis to reduce cerebral ischemia-reperfusion injury

BACKGROUND

The complex pathophysiological changes following cerebral ischemia-reperfusion injury (CIRI) include the accumulation of defective proteins and damaged organelles, which cause massive neuron demise. To preserve cellular homeostasis, the autophagy-lysosomal pathway (ALP) is crucial for neurons to dispose of these substances. Many studies have shown that bone mesenchymal stem cell exosomes (BMSC-Exos) can reduce CIRI. However, the specific mechanisms have not been well elucidated, a fact that limits its widespread clinical use. This study aimed to clarify whether BMSC-Exos could attenuate ALP dysfunction by restoring lysosomal function after CIRI via inhibiting mTOR and then activating TFEB nucleus translocation.

METHODS

In this study, Flow cytometry, Nanoparticle tracking analysis (NTA), Transmission electron microscope (TEM), and Western blot were used to identify the BMSCs and BMSC-Exos used in this experiment as conforming to the requirements. In vivo experiments, SD rats were modeled with temporary middle cerebral artery occlusion (tMCAO), and BMSC-Exos was injected into the tail vein 2 h after modeling. Triphenyl tetrazolium chloride (TTC) staining, modified neurological severity scores (mNSS), corner turn test, and rotating rod test were used to detect neurological deficits in rats after BMSC-Exos intervention. Western blot and Immunofluorescence were used to detect ALP, transcription factor EB(TFEB) nucleus translocation, and mammalian target of rapamycin (mTOR) change at different time points after modeling and after BMSC-Exos intervention. In vitro experiments, pheochromocytoma cells (PC12) cells were subjected to oxygen-glucose deprivation and reperfusion (OGD/R) modeling to mimic CIRI, and were respectively intervened with BMSC-Exos, BMSC-Exos + MHY 1485 (the mTOR agonist), Rapamycin (the mTOR inhibitor). CCK8, Western blot, and Immunofluorescence were used to detect PC12 cell survival, TFEB nucleus translocation, and cathepsin B(CTSB) Immunofluorescence intensity.

RESULTS

We found that ALP dysfunction occurred 72 h after tMCAO, and BMSC-Exos can attenuate ALP dysfunction by restoring lysosomal function. Next, we examined TFEB nucleus translocation and the expression of mTOR, a key regulator of translocation. We found that BMSC-Exos could inhibit mTOR and activate TFEB nucleus translocation. Additional in vitro tests revealed that BMSC-Exos could increase PC12 cell survival after OGD/R, activating TFEB nucleus translocation and enhancing the fluorescence intensity of CTSB, which in turn could be reversed by the mTOR agonist, MHY1485. This effect was similar to another mTOR inhibitor, Rapamycin.

CONCLUSION

BMSC-Exos could attenuate ALP dysfunction by restoring lysosomal function after CIRI by inhibiting mTOR and then promoting TFEB nucleus translocation.

The role of human 5-Lipoxygenase (5-LO) in carcinogenesis - a question of canonical and non-canonical functions

5-Lipoxygenase (5-LO), a fatty acid oxygenase, is the central enzyme in leukotriene (LT) biosynthesis, potent arachidonic acid-derived lipid mediators released by innate immune cells, that control inflammatory and allergic responses. In addition, through interaction with 12- and 15-lipoxgenases, the enzyme is involved in the formation of omega-3 fatty acid-based oxylipins, which are thought to be involved in the resolution of inflammation. The expression of 5-LO is frequently deregulated in solid and liquid tumors, and there is strong evidence that the enzyme plays an important role in carcinogenesis. However, global inhibition of LT formation and signaling has not yet shown the desired success in clinical trials. Curiously, the release of 5-LO-derived lipid mediators from tumor cells is often low, and the exact mechanism by which 5-LO influences tumor cell function is poorly understood. Recent data now show that in addition to releasing oxylipins, 5-LO can also influence gene expression in a lipid mediator-independent manner. These non-canonical functions, including modulation of miRNA processing and transcription factor shuttling, most likely influence cancer cell function and the tumor microenvironment and might explain the low clinical efficacy of pharmacological strategies that previously only targeted oxylipin formation and signaling by 5-LO. This review summarizes the canonical and non-canonical functions of 5-LO with a particular focus on tumorigenesis, highlights unresolved issues, and suggests future research directions.

Loureirin B improves H/R-induced hepatic ischemia-reperfusion injury by downregulating ALOX5 to regulate mitochondrial homeostasis

This study was conceived to explore the role and the mechanism of Loureirin B (LB) in hepatic IRI. The viability of LB-treated AML-12 cells was assessed using CCK-8 assay and inflammatory cytokines were detected using ELISA. The activities of ROS and oxidative stress markers MDA, SOD, and GSH-Px were detected using DCFH-DA and corresponding assay kits. The cell apoptosis and caspase3 activity were estimated with flow cytometry and caspase3 assay kits. The expressions of arachidonate 5-lipoxygenase (ALOX5) and apoptosis- and mitochondrial dynamics-related proteins were detected using western blot. The interaction between LB and ALOX5 was analyzed with molecular docking. The transfection efficacy of oe-ALOX5 was examined with RT-qPCR and western blot. Mitochondrial membrane potential was detected with JC-1 staining and immunofluorescence (IF) assay was employed to estimate mitochondrial fusion and fission. The present work found that LB revived the viability, inhibited inflammatory response, suppressed oxidative stress, repressed the apoptosis, and maintained mitochondrial homeostasis in H/R-induced AML-12 cells, which were all reversed by ALOX5 overexpression. Collectively, LB regulated mitochondrial homeostasis by downregulating ALOX5, thereby improving hepatic IRI.

Transplantation of miR-193b-3p-Transfected BMSCs Improves Neurological Impairment after Traumatic Brain Injury through S1PR3-Mediated Regulation of the PI3K/AKT/mTOR Signaling Pathway

The aim of the present study was to explore the molecular mechanisms by which miR-193b-3p-trans-fected bone marrow mesenchymal stem cells (BMSCs) transplantation improves neurological impairment after traumatic brain injury (TBI) through sphingosine-1-phosphate receptor 3 (S1PR3)-mediated regulation of the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway at the cellular and animal levels. BMSCs were transfected with miR-193b-3p. A TBI cell model was established by oxygen-glucose deprivation (OGD)-induced HT22 cells, and a TBI animal model was established by controlled cortical impact (CCI). Cell apoptosis was detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL), and cell activity was detected by a cell counting kit 8 (CCK-8) assay. Western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the expression of related proteins and genes. In this study, transfection of miR-193b-3p into BMSCs significantly enhanced BMSCs proliferation and differentiation. Transfection of miR-193b-3p reduced the levels of the interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-alpha (TNF-α) inflammatory factors in cells and mouse models, and it inhibited neuronal apoptosis, which alleviated OGD-induced HT22 cell damage and neural function damage in TBI mice. Downstream experiments showed that miR-193b-3p targeting negatively regulated the expression of S1PR3, promoted the activation of the PI3K/AKT/mTOR signaling pathway, and inhibited the levels of apoptosis and inflammatory factors, which subsequently improved OGD-induced neuronal cell damage and nerve function damage in TBI mice. However, S1PR3 overexpression or inhibition of the PI3K/AKT/mTOR signaling pathway using the IN-2 inhibitor weakened the protective effect of miR-193b-3p-transfected BMSCs on HT22 cells. Transplantation of miR-193b-3p-transfected BMSCs inhibits neurological injury and improves the progression of TBI in mice through S1PR3-mediated regulation of the PI3K/AKT/mTOR pathway.

CircCRIM1/microRNA-141-3p/thioredoxin-binding protein axis mediates neuronal apoptosis after cerebral ischemia-reperfusion

Numerous studies have indicated enrichment of circular RNA (circRNA) in the brain takes on a momentous role in cerebral ischemia-reperfusion (CIR) injury. A recent study discovered a novel circCRIM1, was highly expressed in the middle cerebral artery occlusion-reperfusion (MCAO/R) model. Nevertheless, its specific biological function remained unknown. The study was to explore circCRIM1 in CIR-induced neuronal apoptosis. As measured, circCRIM1 and TXNIP were up-regulated, while miR-141-3p was down-regulated in MCAO/R mouse model and OGD/R SH-SY5Y cells. Depleting circCRIM1 reduced the number of apoptotic neurons in MCAO/R rats, increased the number of Nissl bodies, prevented reactive oxygen species production and oxidative stress imbalance in brain tissues, repressed cleaved caspase-3, Bax, and Cyto C protein levels and increased Bcl-2 levels. Overexpression of circCRIM1 further repressed neuronal activity and accelerated apoptosis in OGD/R model, disrupted redox balance. Depleting circCRIM1 had the opposite effect in OGD/R model. Knocking down miR-141-3p or TXNIP weakened the effects of knocking down circCRIM1 or overexpressing circCRIM1, separately. Mechanistically, circCRIM1 exerted an active role in CIR injury via miR-141-3p to mediate TXNIP. All in all, the circCRIM1/miR-141-3p/TXNIP axis might be a latent therapeutic target for CIR injury.

Cross-talk between bioactive lipid mediators and the unfolded protein response in ischemic stroke

Ischemic cerebral stroke is a severe medical condition that affects about 15 million people every year and is the second leading cause of death and disability globally. Ischemic stroke results in neuronal cell death and neurological impairment. Current therapies may not adequately address the deleterious metabolic changes and may increase neurological damage. Oxygen and nutrient depletion along with the tissue damage result in endoplasmic reticulum (ER) stress, including the Unfolded Protein Response (UPR), and neuroinflammation in the affected area and cause cell death in the lesion core. The spatio-temporal production of lipid mediators, either pro-inflammatory or pro-resolving, decides the course and outcome of stroke. The modulation of the UPR as well as the resolution of inflammation promotes post-stroke cellular viability and neuroprotection. However, studies about the interplay between the UPR and bioactive lipid mediators remain elusive and this review gives insights about the crosstalk between lipid mediators and the UPR in ischemic stroke. Overall, the treatment of ischemic stroke is often inadequate due to lack of effective drugs, thus, this review will provide novel therapeutical strategies that could promote the functional recovery from ischemic stroke.

The Role of microRNAs in Epigenetic Regulation of Signaling Pathways in Neurological Pathologies

In recent times, there has been a significant increase in researchers' interest in the functions of microRNAs and the role of these molecules in the pathogenesis of many multifactorial diseases. This is related to the diagnostic and prognostic potential of microRNA expression levels as well as the prospects of using it in personalized targeted therapy. This review of the literature analyzes existing scientific data on the involvement of microRNAs in the molecular and cellular mechanisms underlying the development of pathologies such as Alzheimer's disease, cerebral ischemia and reperfusion injury, and dysfunction of the blood-brain barrier.

GATA6 Inhibits Neuronal Autophagy and Ferroptosis in Cerebral ischemia-reperfusion Injury Through a miR-193b/ATG7 axis-dependent Mechanism

Ferroptosis is a newly described form of regulated necrotic cell death, which is engaged in the pathological cell death related to stroke, contributing to cerebral ischemia-reperfusion (I/R) injury. Therefore, we performed this study to clarify the role of GATA6 in neuronal autophagy and ferroptosis in cerebral I/R injury. The cerebral I/R injury-related differentially expressed genes (DEGs) as well as the downstream factors of GATA6 were predicted bioinformatically. Moreover, the relations between GATA6 and miR-193b and that between miR-193b and ATG7 were evaluated by chromatin immunoprecipitation and dual-luciferase reporter assays. Besides, neurons were treated with oxygen-glucose deprivation (OGD), followed by overexpression of GATA6, miR-193b, and ATG7 alone or in combination to assess neuronal autophagy and ferroptosis. At last, in vivo experiments were performed to explore the impacts of GATA6/miR-193b/ATG7 on neuronal autophagy and ferroptosis in a rat model of middle cerebral artery occlusion (MCAO)-stimulated cerebral I/R injury. It was found that GATA6 and miR-193b were poorly expressed in cerebral I/R injury. GATA6 transcriptionally activated miR-193b to downregulate ATG7. Additionally, GATA6-mediated miR-193b activation suppressed neuronal autophagy and ferroptosis in OGD-treated neurons by inhibiting ATG7. Furthermore, GATA6/miR-193b relieved cerebral I/R injury by restraining neuronal autophagy and ferroptosis via downregulation of ATG7 in vivo. In summary, GATA6 might prevent neuronal autophagy and ferroptosis to alleviate cerebral I/R injury via the miR-193b/ATG7 axis.

The role of miRNAs in insulin resistance and diabetic macrovascular complications - A review

Diabetes is the most prevalent metabolic disturbance disease and has been regarded globally as one of the principal causes of mortality. Diabetes is accompanied by several macrovascular complications, including stroke, coronary artery disease (CAD), and cardiomyopathy as a consequence of atherosclerosis. The onset of type 2 diabetes is closely related to insulin resistance (IR). miRNAs have been linked to various metabolic processes, including glucose homeostasis, regulation of lipid metabolism, gluconeogenesis, adipogenesis, glucose transporter type 4 expression, insulin sensitivity, and signaling. Consequently, miRNA dysregulation mediates IR in some target organs, comprising liver, muscle, and adipose tissue. Moreover, miRNAs are crucial in developing diabetes and its associated macrovascular complications through their roles in several signaling pathways implicated in inflammation, apoptosis, cellular survival and migration, the proliferation of vascular smooth muscle cells, neurogenesis, angiogenesis, autophagy, oxidative stress, cardiac remodeling, and fibrosis. Therefore, the purpose of this review is to clarify the role of miRNAs in hepatic, muscle, and adipose tissue IR and explain their roles in the pathogenesis of macrovascular diabetic complications, including stroke, CAD, and cardiomyopathy. Also, explain their roles in gestational diabetes mellitus (GDM). Besides, this review discusses the latest updates on the alteration of miRNA expression in diabetic macrovascular complications.

MicroRNA-27a Regulates Ferroptosis Through SLC7A11 to Aggravate Cerebral ischemia-reperfusion Injury

Cerebral ischemia-reperfusion (I/R) injury is an inevitable issue in the treatment of ischemic stroke, which has a high disability rate and seriously threatens the living quality of patients. Previous studies have demonstrated that ferroptosis, which plays a crucial role in ischemia-reperfusion injury, can be accelerated by microRNA-27a (miR-27a). However, the mechanism by which miR-27a regulates ferroptosis in cerebral ischemia-reperfusion injury remains unknown. In this study, Male Sprague-Dawley rats were subjected to a middle cerebral artery occlusion (MCAO), then restored blood flow. Neurological function score and TTC staining were used to evaluate brain tissue injury and the infarct volume. The relative expression level of miR-27a was detected by qPCR. The relative expression levels of glutathione peroxidase 4(GPx4), solute carrier family 7 member 11 (SLC7A11) proteins were analyzed by Western Blot. The contents of GSH, Fe and malonaldehyde (MDA) were detected by corresponding detection kits, and the target gene of miR-27a was confirmed by dual luciferase reporter gene technique. It was found the relative expression level of miR-27a was increased and ferroptosis was aggravated as reperfusion time went by. Also, brain tissue injury and ferroptosis were exacerbated with agomiR-27a intervention, while these effects were reversed with antagomiR-27a intervention. In addition, the combined intervention of agomiR-27a and Fer-1 alleviated the brain tissue injury and ferroptosis. The results of dual luciferase reporter gene technique indicated SLC7A11 as the target gene of miR-27a. In the current study, miR-27a upregulates ferroptosis to aggravate cerebral ischemia-reperfusion injury by SLC7A11.

A systematic review of the research progress of non-coding RNA in neuroinflammation and immune regulation in cerebral infarction/ischemia-reperfusion injury

Cerebral infarction/ischemia-reperfusion injury is currently the disease with the highest mortality and disability rate of cardiovascular disease. Current studies have shown that nerve cells die of ischemia several hours after ischemic stroke, which activates the innate immune response in the brain, promotes the production of neurotoxic substances such as inflammatory cytokines, chemokines, reactive oxygen species and − nitrogen oxide, and mediates the destruction of blood-brain barrier and the occurrence of a series of inflammatory cascade reactions. Meanwhile, the expression of adhesion molecules in cerebral vascular endothelial cells increased, and immune inflammatory cells such as polymorphonuclear neutrophils, lymphocytes and mononuclear macrophages passed through vascular endothelial cells and entered the brain tissue. These cells recognize antigens exposed by the central nervous system in the brain, activate adaptive immune responses, and further mediate secondary neuronal damage, aggravating neurological deficits. In order to reduce the above-mentioned damage, the body induces peripheral immunosuppressive responses through negative feedback, which increases the incidence of post-stroke infection. This process is accompanied by changes in the immune status of the ischemic brain tissue in local and systemic systems. A growing number of studies implicate noncoding RNAs (ncRNAs) as novel epigenetic regulatory elements in the dysfunction of various cell subsets in the neurovascular unit after cerebral infarction/ischemia-reperfusion injury. In particular, recent studies have revealed advances in ncRNA biology that greatly expand the understanding of epigenetic regulation of immune responses and inflammation after cerebral infarction/ischemia-reperfusion injury. Identification of aberrant expression patterns and associated biological effects of ncRNAs in patients revealed their potential as novel biomarkers and therapeutic targets for cerebral infarction/ischemia-reperfusion injury. Therefore, this review systematically presents recent studies on the involvement of ncRNAs in cerebral infarction/ischemia-reperfusion injury and neuroimmune inflammatory cascades, and elucidates the functions and mechanisms of cerebral infarction/ischemia-reperfusion-related ncRNAs, providing new opportunities for the discovery of disease biomarkers and targeted therapy. Furthermore, this review introduces clustered regularly interspaced short palindromic repeats (CRISPR)-Display as a possible transformative tool for studying lncRNAs. In the future, ncRNA is expected to be used as a target for diagnosing cerebral infarction/ischemia-reperfusion injury, judging its prognosis and treatment, thereby significantly improving the prognosis of patients.

MicroRNA-193b-3p reduces oxidative stress and mitochondrial damage in rats with cerebral ischemia-reperfusion injury via the seven in absentia homolog 1/Jun N-terminal kinase pathway

Ischemic stroke is one of the major causes of death and disability among adults. This study sought to explore the mechanism of microRNA (miR)-193b-3p in rats with cerebral ischemia-reperfusion (I/R) injury. The cerebral I/R injury models of rats were established using the suture-occluded method. The pathological changes were observed, and oxidative stress (OS) and mitochondrial function indexes in rat brain tissue were examined. The levels of miR-193b-3p and seven in absentia homolog 1 (SIAH1) were detected. miR-193b-3p agomir or antagomir was injected into the lateral ventricle of I/R rats to overexpress or inhibit miR-193b-3p expression. The targeting relationship between miR-193b-3p and SIAH1 was verified. The effect of SIAH1 overexpression on brain injury in I/R rats was investigated by injecting the lentivirus vector into the lateral ventricle. The phosphorylation level of Jun N-terminal kinase (JNK) was identified. miR-193b-3p was lowly expressed in I/R rats. Overexpression of miR-193b-3p alleviated the pathological damage of I/R rats and limited the OS and mitochondrial damage. miR-193b-3p targeted SIAH1. Overexpression of SIAH1 partially reversed the protection of miR-193b-3p overexpression against cerebral I/R injury. p-JNK was up-regulated in I/R rats and overexpression of miR-193b-3p inhibited p-JNK. Overall, overexpression of miR-193b-3p targeted SIAH1 to inhibit the activation of the JNK pathway and protect rats against cerebral I/R injury.

MicroRNA-193b impairs muscle growth in mouse models of type 2 diabetes by targeting the PDK1/Akt signalling pathway

AIMS/HYPOTHESIS

Type 2 diabetes is associated with a reduction in skeletal muscle mass; however, how the progression of sarcopenia is induced and regulated remains largely unknown. We aimed to find out whether a specific microRNA (miR) may contribute to skeletal muscle atrophy in type 2 diabetes.

METHODS

Adeno-associated virus (AAV)-mediated skeletal muscle miR-193b overexpression in C57BLKS/J mice, and skeletal muscle miR-193b deficiency in db/db mice were used to explore the function of miR-193b in muscle loss. In C57BL/6 J mice, tibialis anterior-specific deletion of 3-phosphoinositide-dependent protein kinase-1 (PDK1), mediated by in situ AAV injection, was used to confirm whether miR-193b regulates muscle growth through PDK1. Serum miR-193b levels were also analysed in healthy individuals (n = 20) and those with type 2 diabetes (n = 20), and correlations of miR-193b levels with HbA_1c, fasting blood glucose (FBG), body composition, triacylglycerols and C-peptide were assessed.

RESULTS

In this study, we found that serum miR-193b levels increased in individuals with type 2 diabetes and negatively correlated with muscle mass in these participants. Functional studies further showed that AAV-mediated overexpression of miR-193b induced muscle loss and dysfunction in healthy mice. In contrast, suppression of miR-193b attenuated muscle loss and dysfunction in db/db mice. Mechanistic analysis revealed that miR-193b could target Pdk1 expression to inactivate the Akt/mammalian target of rapamycin (mTOR)/p70S6 kinase (S6K) pathway, thereby inhibiting protein synthesis. Therefore, knockdown of PDK1 in healthy mice blocked miR-193b-induced inactivation of the Akt/mTOR/S6K pathway and impairment of muscle growth.

CONCLUSIONS/INTERPRETATION

Our results identified a previously unrecognised role of miR-193b in muscle function and mass that could be a potential therapeutic target for treating sarcopenia.

MiR-19 3b regulated the formation of coat colors by targeting WNT10A and GNAI2 in Cashmere goats

MiRNAs as a series of small noncoding RNAs that play a crucial part in regulating coat color and hair follicle development. In the previous Solexa sequencing experiments, there were many miRNAs expressed differentially in alpacas with different coat color, including miR-193b.But the mechanism of miR-193b in mammalian pigmentation is still unknown. In this study, bioinformatics analysis showed that WNT10A and GNAI2 might be the target genes of miR-193b. qRT-PCR showed the expression of miR-193b in white Cashmere goats' skins was obviously lower than that in browns, and the expression of WNT10A and GNAI2 were similar with miR-193b. The protein levels of WNT10A and GNAI2 indicated the same findings. Furthermore, the expression of WNT10A and GNAI2 in keratinocytes were analyzed from mRNA and protein levels, the results manifested that the group of overexpression of miR-193b in HaCaT cells increased the expressions of target genes, and miR-193b inhibition group reduced expressions. Luciferase report assays confirmed that the targeting relationship between miR-193b and target genes (WNT10A and GNAI2), the results showed that miR-193b was positively correlated with target genes. These experimental data showed that miR-193b might participate in adjustment of coat color in skin tissue of Cashmere goat by targeting WNT10A and GNAI2.

Inhibition of the miR-193b-3p protects against oxidized low-density lipoprotein-induced HUVECs injury by upregulating ALDH2

Atherosclerosis (AS) is the most dangerous factor for human death, which is a lipid-driven chronic inflammatory disorder of the arteries. Growing evidence has showed that microRNAs play an important role in AS. However, the role of mir-193b-3p in atherosclerosis has been poorly studied to date. Therefore, we focused on the potential role of miR-193b-3p in atherosclerosis. The expressions of miR-193b-3p in the serum of AS patients were detected. We also established an oxidized low density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cells (HUVECs) apoptosis model in vitro. The mRNA and protein levels of target molecules were detected by RT-qPCR and Western blotting. Apoptosis of HUVECs was determined by Annexin V/PI staining on a flow cytometry. The potential molecular targets of miR-193b-3p were investigated by applying such technologies as dual-luciferase reporter and RIP assay. Our study showed that miR-193b-3p expression level was significantly lower in AS patients than controls. ROC curve analysis showed that the areas under the curve (AUC) of plasma miR-193b-3p was 0.859. We also found that miR-193b-3p was decreased in ox-LDL-induced HUVECs and knockdown of miR-193b-3p suppressed ox-LDL-induced HUVECs injury. By using bioinformatics analysis, aldehyde dehydrogenase (ALDH2) was predicted as a downstream target of miR-193b-3p. The ALDH2 gene is also involved in the development of atherosclerosis. Meanwhile, inhibition of miR-193b-3p and ALDH2 protects ox-LDL-induced HUVECs against endoplasmic-reticulum (ER) stress. In conclusion, inhibition of miR-193b-3p was able to suppress ox-LDL-induced injury in AS through targeting ALDH2 and reducing ER stress.

Overexpression of miR-149-5p Attenuates Cerebral Ischemia/Reperfusion (I/R) Injury by Targeting Notch2

Ischemic stroke is one of the leading causes of death and disability worldwide. Although miR-149-5p downregulation is observed in rats after ischemia/reperfusion (I/R) injury, its function and role in ischemic stroke remain unclear. This study aimed to investigate the roles of miR-149-5p in I/R injury. The results showed that miR-149-5p was significantly downregulated in brain tissues of rats subjected to middle cerebral artery occlusion (MCAO) and primary cortical neurons subject to oxygen and glucose deprivation (OGD). MiR-149-5p overexpression effectively reduced MCAO/R-induced infarct volume, neurological score, and brain water content as well as OGD/R-induced cortical neurons apoptosis and OGD/R-induced expression of TNF-α, IL-4, IL-6, IL-1β, and COX-2. Moreover, Notch2 was identified as a target of miR-149-5p and Notch2 overexpression significantly attenuated the inhibitory effects of miR-149-5p mimics on inflammation and apoptosis. Taken together, our study revealed that miR-149-5p overexpression protects the rat brain against I/R injury by regulating Notch2-mediated inflammation and apoptosis pathway.

miR-129-5p Ameliorates Ischemic Brain Injury by Binding to SIAH1 and Activating the mTOR Signaling Pathway

Aberrant expression of microRNAs (miRNAs) has been linked with ischemic brain injury (IBI), but the mechanistic actions behind the associated miRNAs remain to be determined. Of note, miR-129-5p was revealed to be downregulated in the serum of patients with IBI. In silico prediction identified a putative target gene, siah E3 ubiquitin protein ligase 1 (SIAH1), of miR-129-5p. Accordingly, this study plans to clarify the functional relevance of the interplay of miR-129-5p and SIAH1 in IBI. IBI was modeled by exposing human hippocampal neuronal cells to oxygen-glucose deprivation (OGD) in vitro and by occluding the middle cerebral artery (MCAO) in a mouse model in vivo. Apoptosis of hippocampal neuronal cells was assessed by annexin V-FITC/PI staining and TUNEL staining. The area of cerebral infarction was measured using TTC staining, along with neurological scoring on modeled mice. Loss of hippocampal neuronal cells in the peri-infarct area was monitored using Nissl staining. Downregulated miR-129-5p expression was found in OGD-induced hippocampal neuronal cells and MCAO-treated mice. Mechanistically, miR-129-5p was validated to target and inhibit SIAH1 through the application of dual-luciferase reporter assay. Additionally, enforced miR-129-5p inhibited the apoptosis of OGD-induced cells and decreased the cerebral infarct area, neurological scores and apoptosis of hippocampal neuronal cells by downregulating SIAH1 and activating the mTOR signaling pathway. Taken together, the results of this study reveal the important role and underlying mechanism of miR-129-5p in IBI, providing a promising biomarker for preventive and therapeutic strategies.

miR-451 protects against ischemic stroke by targeting Phd3

Ischemic stroke still remains a therapeutic challenge due to its complex pathogenesis and implications. By screening biomarkers in the peripheral blood of ischemic stroke patients, miR-451 was identified as a differentially expressed miRNA along the disease course of ischemic stroke. To investigate the role of miR-451, middle cerebral artery occlusion (MCAO) was performed as an ischemic stroke model in mice. Intracerebroventricular administration of miR-451 mimic in the MCAO mice significantly decreased infarct size, while miR-451 inhibitor significantly increased infarct size. To understand the molecular mechanism of the protective effect of miR-451, Phd3 (also Egln3) was validated as a new miR-451 target. Either fewer or more Phd3-positive cells were observed in brain sections from mice receiving miR-451 mimic or inhibitor, respectively. In addition, the levels of p53 (a known Phd3 target) were significantly downregulated when the levels of Phd3 were reduced, suggesting its participation in reducing apoptosis after the miR-451 administration. Indeed, reduced apoptosis upon miR-451 mimic administration was detected by TUNEL staining. In conclusion, this study demonstrated a new protective role of miR-451 in cerebral ischemia and identified Phd3 as a novel miR-451 target, linking the mechanism to the involvement of p53 in the regulation of apoptosis during the pathogenesis of ischemic stroke.

MicroRNA-532-5p protects against cerebral ischemia-reperfusion injury by directly targeting CXCL1

We investigated the function of microRNA (miR)-532-5p in cerebral ischemia-reperfusion injury (CI/RI) and the underlying mechanisms using oxygen-glucose deprivation and reperfusion (OGD/R)-treated SH-SY5Y cells and middle cerebral artery occlusion (MCAO) model rats. MiR-532-5p levels were significantly downregulated in OGD/R-treated SH-SY5Y cells and the brain tissues of MCAO model rats. MiR-532-5p overexpression significantly reduced apoptosis, reactive oxygen species (ROS), and inflammation in the OGD/R-induced SH-SY5Y cells. Bioinformatics analysis using the targetscan and miRDB databases as well as dual luciferase reporter assays confirmed that miR-532-5p directly binds to the 3’UTR of C-X-C Motif Ligand 1 (CXCL1). Methylation-specific PCR (MSP) analysis showed that miR-532-5p expression was reduced in OGD/R-treated SH-SY5Y cells because of miR-532-5p promoter hypermethylation. Moreover, 5-azacytidine, a methylation inhibitor, restored miR-532-5p expression in OGD/R-treated SH-SY5Y cells. Brain tissues of MCAO model rats showed significantly increased cerebral infarction areas, cerebral water, neuronal apoptosis, and activated CXCL1/CXCR2/NF-κB signaling, but these effects were alleviated by intraventricular injection of miR-532-5p agomir. These findings demonstrate that miR-532-5p overexpression significantly reduces in vitro and in vivo CI/RI by targeting CXCL1. Thus, miR-532-5p is a potential therapeutic target for patients with CI/RI.

Physcion Protects Rats Against Cerebral Ischemia-Reperfusion Injury via Inhibition of TLR4/NF-kB Signaling Pathway

Background

Ischemic stroke (IS) is characterized by the rapid loss of brain function due to ischemia. Physcion has been found to have a neuroprotective effect against cerebral ischemia-reperfusion (I/R) injury. However, the mechanism by which physcion regulates cerebral I/R injury remains largely unknown.

Methods

An oxygen-glucose deprivation/reperfusion (OGD/R) model in SH-SY5Y cells and a rat cerebral ischemia-reperfusion (I/R) model were established, respectively. CCK-8 and flow cytometry assays were used to detect the viability and apoptosis of SH-SY5Y cells. Moreover, enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of SOD, MDA, GSH-Px, TNF-α, IL-1β, IL-6 and IL-10 in the supernatant of SH-SY5Y cells. Meanwhile, Western blot assay was used to detect the expressions of TLR4, p-p65 and p-IκB in SH-SY5Y cells and I/R rats.

Results

In this study, physcion treatment significantly rescued OGD/R-induced neuronal injury. In addition, physcion decreased inflammatory response in SH-SY5Y cells after OGD/R insult, as shown by the decreased levels of the pro-inflammatory factors TNF-α, IL-1β, IL-6 and IL-10. Moreover, physcion attenuated the oxidative stress in OGD/R-treated SY-SY5Y cells, as evidenced by the increased SOD and GSH levels and the decreased ROS and MDA levels. Meanwhile, physcion significantly reduced cerebral infarction, attenuated neuronal injury and apoptosis in I/R rats. Furthermore, physcion markedly decreased the expressions of TLR4, p-NF-κB p65 and p-IκB in the brain tissues of rats subjected to I/R and in SH-SY5Y cells exposed to OGD/R.

Conclusion

In conclusion, our study indicated that physcion protected neuron cells against I/R injury in vitro and in vivo by inhibition of the TLR4/NF-kB pathway; thus, physcion might serve as a promising therapeutic candidate for IS.

Long Non-coding RNAMALAT1 Knockdown Alleviates Cerebral Ischemia/Reperfusion Injury of Rats Through Regulating the miR-375/PDE4D Axis

Objectives: Cerebral ischemic/reperfusion injury (CI/RI) is the clinical manifestation of cerebral ischemic stroke, which severely affects the health and life of the patients. We aimed to investigate the regulatory mechanism of long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on CI/RI in this study.

Methods: The expression of lncRNA MALAT1 and miR-375 was detected by qRT-PCR. MTT was utilized to measure the viability of PC-12 cells. The levels of lactate dehydrogenase (LDH), superoxide dismutase (SOD), and reactive oxygen species (ROS) were detected by LDH assay, SOD assay, and ROS assay, respectively. The apoptosis rate of PC-12 cells was measured by flow cytometry analysis. Through enzyme-linked immunosorbent assay, the levels of NF-α, IL-1β, and IL-6 were determined. The interactions between miR-375 and MALAT1/PDE4D were predicted by Starbase/Targetscan software and verified by the dual-luciferase reporter assay. Western blot assay was performed to determine the protein expression of Bcl-2, Caspase-3, and PDE4D.

Results: LncRNA MALAT1 expression was highly upregulated in the middle cerebral artery occlusion (MCAO)/reperfusion (R) model of rats. Both MALAT1 downregulation and miR-375 upregulation reversed the inhibitory effect of oxygen and glucose deprivation (OGD)/R on cell viability and the promoting effects on LDH level, cell apoptosis, and inflammatory factors levels. MALAT1 targeted miR-375, whereas miR-375 targeted PDE4D. Overexpression of miR-375 attenuated OGD/R-induced injury in PC-12 cells by targeting PDE4D. Both the low expression of miR-375 and high expression of PDE4D reversed the promoting effect of MALAT1 knockdown on SOD level and the inhibitory effects on ROS level, inflammatory factor levels, and cell apoptosis.

Conclusion: Suppression of MALAT1 alleviates CI/RI of rats through regulating the miR-375/PDE4D axis. This study provides a possible therapeutic strategy for human CI/RI in clinic.

miRNAs and Leukotrienes in Respiratory Syncytial Virus Infection

MicroRNAs (miRNAs) are small, non-coding RNAs that regulate posttranscription by binding to 3'-untranslated regions of target mRNAs. Recent functional studies have elucidated mechanisms that miRNAs regulate leukotriene synthesis by perturbing arachidonic acid metabolism. Both microarrays and high-throughput sequencing revealed distinct differential expression of miRNAs in children with respiratory syncytial virus (RSV) infection compared with healthy controls. Abnormal miRNA expression may contribute to higher leukotriene levels, which is associated with airway hyperreactivity. Targeting miRNAs may benefit to restore the homeostasis of inflammatory reaction and provide new strategies to alleviate airway hyperreactivity induced by RSV. In this article, we provide an overview of the current knowledge about miRNAs modulating leukotrienes through regulation of arachidonic acid metabolism with a special focus on miRNAs aberrantly expressed in children with RSV infection.

Modulation of microRNA processing by 5-lipoxygenase

The miRNA biogenesis is tightly regulated to avoid dysfunction and consequent disease development. Here, we describe modulation of miRNA processing as a novel noncanonical function of the 5-lipoxygenase (5-LO) enzyme in monocytic cells. In differentiated Mono Mac 6 (MM6) cells, we found an in situ interaction of 5-LO with Dicer, a key enzyme in miRNA biogenesis. RNA sequencing of small noncoding RNAs revealed a functional impact, knockout of 5-LO altered the expression profile of several miRNAs. Effects of 5-LO could be observed at two levels. qPCR analyses thus indicated that (a) 5-LO promotes the transcription of the evolutionarily conserved miR-99b/let-7e/miR-125a cluster and (b) the 5-LO-Dicer interaction downregulates the processing of pre-let-7e, resulting in an increase in miR-125a and miR-99b levels by 5-LO without concomitant changes in let-7e levels in differentiated MM6 cells. Our observations suggest that 5-LO regulates the miRNA profile by modulating the Dicer-mediated processing of distinct pre-miRNAs. 5-LO inhibits the formation of let-7e which is a well-known inducer of cell differentiation, but promotes the generation of miR-99b and miR-125a known to induce cell proliferation and the maintenance of leukemic stem cell functions.

Exosomes Secreted From Bone Marrow Mesenchymal Stem Cells Attenuate Oxygen-Glucose Deprivation/Reoxygenation-Induced Pyroptosis in PC12 Cells by Promoting AMPK-Dependent Autophagic Flux

Background: Cerebral ischemia–reperfusion (I/R) injury can lead to severe dysfunction, and its treatment is difficult. It is reported that nucleotide-binding domain and leucine-rich repeat family protein 3 (NLRP3) inflammasome-mediated cell pyroptosis is an important part of cerebral I/R injury and the activation of autophagy can inhibit pyroptosis in some tissue injury. Our previous study found that the protective effects of bone marrow mesenchymal stem cells (BMSCs) in cerebral I/R injury may be associated with the regulation of autophagy. Recent studies have demonstrated that exosomes secreted from BMSCs (BMSC-Exos) may play an essential role in the effective biological performance of BMSCs and the protective mechanism of BMSC-Exos is associated with the activation of autophagy and the remission of inflammation, but it has not been reported in studies of cerebral I/R injury. We aimed to investigate the effects of BMSC-Exos on cerebral I/R injury and determine if the mechanism is associated with the regulation of pyroptosis and autophagic flux.

Method: PC12 cells were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to induce cerebral I/R in vitro and were cocultured with BMSC-Exos. Cell viability was determined with CCK-8 and lactate dehydrogenase (LDH) detection kits. Scanning electron microscopy (SEM), Hoechst 33342/propidium iodide (PI) double staining, 2′,7′-dichlorodihydrofluorescein diacetate assay, immunofluorescence, Western blot, and Enzyme-linked immunosorbent assay (ELISA) were used to detect cell pyroptosis. Furthermore, transmission electron microscopy (TEM), GFP-RFP-LC3 adenovirus transfection, and Western blot were used to detect autophagic flux and its influence on pyroptosis. Finally, coimmunoprecipitation was used to detect the binding interaction between NLRP3 and LC3.

Results: BMSC-Exos increased cell viability in OGD/R. The inhibitory effect of BMSC-Exos on pyroptosis was comparable to the NLRP3 inhibitor MCC950 and was reversed by NLRP3 overexpression. Furthermore, BMSC-Exos promoted autophagic flux through the AMP-activated kinase (AMPK)/mammalian target of the rapamycin pathway, whereas chloroquine, AMPK silencing, and compound C blocked the inhibitory effect on pyroptosis.

Conclusions: BMSC-Exos can protect PC12 cells against OGD/R injury via attenuation of NLRP3 inflammasome-mediated pyroptosis by promoting AMPK-dependent autophagic flux.

MiR-410-3p overexpression ameliorates neurological deficits in rats with hypoxic-ischemic brain damage

Neonatal hypoxic-ischemic encephalopathy (HIE) is major cause of neonatal death or long-term neurodevelopmental disabilities, which becomes a major practical problem currently in clinic. Whereas, its pathophysiology and underlying molecular mechanism is not clear. MicroRNAs are involved in the normal growth and development of neuronal cells. Herein, the objective of this research was to examine the roles of miR-410-3p in neurological deficits, neuronal injury and neuron apoptosis after hypoxic-ischemic and to explore its associated mechanisms. We established the hypoxic-ischemic brain damage (HIBD) model and oxygen glucose deprivation (OGD) model. Zea-longa score and TTC staining were used to detect the acute cerebral dysfunction after HIBD. QPCR verification exhibited notable downregulation of miR-410-3p expression at 24 h in rats after HIBD as well as that in PC12, SY5Y cells and primary cortical neurons post OGD. To further determine the function of miR-410-3p, lentivirus-mediated overexpression virus was applied in vivo and in vitro. Behavioral tests, including Morris water maze, open field test, Y maze test, neurological severity score and rotating rod test, were performed to evaluate long-term behavioral changes of rats at 1 month post HIBD. The results showed that the number of cells together with the axonal length were reduced post OGD. While the increase of cells number and the axonal length was measured after upregulating miR-410-3p. Meanwhile, miR-410-3p overexpression inhibited neuron apoptosis and enhanced neuronal survival. In addition, long-term motor and cognitive functions were remarkably recovered in HIBD rats with miR-410-3p overexpression. Together, miR-410-3p exerts a critical role in protecting neuronal growth as well as promoting motor and cognitive function recovery in neonatal rats subjected to HIBD. The current study therefore provides critical insights to develop the activator of miR-410-3p for the clinical treatment of HIBD in future clinic trial.

Lipids and Lipid Mediators Associated with the Risk and Pathology of Ischemic Stroke

Stroke is a severe neurological disorder in humans that results from an interruption of the blood supply to the brain. Worldwide, stoke affects over 100 million people each year and is the second largest contributor to disability. Dyslipidemia is a modifiable risk factor for stroke that is associated with an increased risk of the disease. Traditional and non-traditional lipid measures are proposed as biomarkers for the better detection of subclinical disease. In the central nervous system, lipids and lipid mediators are essential to sustain the normal brain tissue structure and function. Pathways leading to post-stroke brain deterioration include the metabolism of polyunsaturated fatty acids. A variety of lipid mediators are generated from fatty acids and these molecules may have either neuroprotective or neurodegenerative effects on the post-stroke brain tissue; therefore, they largely contribute to the outcome and recovery from stroke. In this review, we provide an overview of serum lipids associated with the risk of ischemic stroke. We also discuss the role of lipid mediators, with particular emphasis on eicosanoids, in the pathology of ischemic stroke. Finally, we summarize the latest research on potential targets in lipid metabolic pathways for ischemic stroke treatment and on the development of new stroke risk biomarkers for use in clinical practice.