Protective Effect of miR-340-5p against Brain Injury after Intracerebral Hemorrhage by Targeting PDCD4

HDAC Inhibitor SAHA Alleviates Pyroptosis by up-regulating miR-340 to Inhibit NEK7 Signaling in Subarachnoid Hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is a cerebral hemorrhagic disease with a high disability and fatality rate. Cell pyroptosis is involved in the brain injury following SAH. Here, we explored the effect of HDAC inhibitor SAHA against cell pyroptosis after SAH.

METHODS

The rat SAH model was established by endovascular perforation and the rat microglia were treated with 25 μm oxyhemoglobin (OxyHb) for 24 h to mimic SAH model in vitro. Neurological score and brain edema were assessed in rat SAH model. TUNEL staining detected apoptosis. qRT-PCR and western blotting were employed to detect expression levels of miR-340, NEK7 and inflammatory cytokines. ELISA assay determined the secretion of IL-1β and IL-18 in rat serum and cell supernatant. A lactate dehydrogenase (LDH) kit measured the LDH activity in rat primary microglia. Microglia pyroptosis was detected by flow cytometry. RIP and dual luciferase reporter assays confirmed the binding relationship between miR-340 and NEK7.

RESULTS

SAHA alleviated neurological dysfunction, inflammatory injury and microglia pyroptosis in SAH rats. SAHA suppressed LDH release, inflammatory factor expression and pyroptosis in microglia treated with OxyHb. Meanwhile, SAHA increased miR-340 expression and inhibited NEK7 level in vivo and in vitro SAH models. Further, miR-340 directly targeted NEK7 to inhibit the NLRP3 signaling pathway. Knockdown of miR-340 or overexpression of NEK7 reversed the suppressive effects of SAHA on microglia inflammation and pyroptosis. Additionally, knockdown of NEK7 impaired microglia inflammation and pyroptosis induced by miR-340 inhibitor.

CONCLUSION

HDAC inhibitor SAHA ameliorates microglia pyroptosis in SAH through triggering miR-340 expression to suppress NEK7 signaling. This novel mechanism provides promise for SAHA in SAH treatment.

CircRBM33 induces endothelial dysfunction by targeting the miR-6838-5p/PDCD4 axis affecting blood-brain barrier in mice with cerebral ischemia-reperfusion injury

BACKGROUND

circRNAs (circRNAs) are involved in the process of cerebral ischemia-reperfusion injury (CI/RI). Our study aims to explore circRBM33 in the endothelial function of the blood-brain barrier (BBB).

METHODS

The mouse middle cerebral artery occlusion model (MCAO) was established and restored to perfusion, and OGD/R-induced endothelial cells were used to simulate CI/RI. circRBM33, miR-6838-5p and PDCD4, as well as Occludin, ZO-1 and Claudin-5 TJs were evaluated by quantitative PCR and Western blot. The ring structure of circRBM33 was verified by RNAse R and actinomycin D experiments. MTT and LDH Cytotoxicity assay determined viability and toxicity, and flow cytometry determined apoptosis rate. Inflammatory cytokines and the number of microglia in brain tissue were measured by ELISA and IHC. The interaction between genes was verified by RIP and dual luciferase reporter assay.

RESULTS

circRBM33 was a circrRNA present in the cytoplasm and up-regulated in the brain tissue of MCAO mice and OGD/R-induced endothelial cells. Silenced circRBM33 promoted Occludin, ZO-1, and Claudin-5 expression and cell proliferation, and inhibited cytotoxicity, inflammatory response, and apoptosis. Functionally, circRBM33-absorbed miR-6838-5p was involved in regulating PDCD4, leading to endothelial cell dysfunction, and thus affecting the function of the BBB.

CONCLUSIONS

circRBM33 by mediating miR-6838-5p/PDCD4 axis induces endothelial dysfunction, thereby affecting the BBB in mice with CI/RI.

MicroRNAs modulate neuroinflammation after intracerebral hemorrhage: Prospects for new therapy

Intracerebral hemorrhage (ICH) is the most common subtype of hemorrhagic stroke. After ICH, blood components extravasate from vessels into the brain, activating immune cells and causing them to release a series of inflammatory mediators. Immune cells, together with inflammatory mediators, lead to neuroinflammation in the perihematomal region and the whole brain, and neuroinflammation is closely related to secondary brain injury as well as functional recovery of the brain. Despite recent progress in understanding the pathophysiology of ICH, there is still no effective treatment for this disease. MicroRNAs (miRNAs) are non-coding RNAs 17-25 nucleotides in length that are generated naturally in the human body. They bind complementarily to messenger RNAs and suppress translation, thus regulating gene expression at the post-transcriptional level. They have been found to regulate the pathophysiological process of ICH, particularly the neuroinflammatory cascade. Multiple preclinical studies have shown that manipulating the expression and activity of miRNAs can modulate immune cell activities, influence neuroinflammatory responses, and ultimately affect neurological functions after ICH. This implicates the potentially crucial roles of miRNAs in post-ICH neuroinflammation and indicates the possibility of applying miRNA-based therapeutics for this disease. Thus, this review aims to address the pathophysiological roles and molecular underpinnings of miRNAs in the regulation of neuroinflammation after ICH. With a more sophisticated understanding of ICH and miRNAs, it is possible to translate these findings into new pharmacological therapies for ICH.

MiR-340-5p alleviates neuroinflammation and neuronal injury via suppressing STING in subarachnoid hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is a severe acute neurological disorder. SAH causes neuroinflammation and leads to early brain injury (EBI) and secondary injury. MicroRNAs are crucial regulators in a variety of neurological diseases. This study was performed to decipher how miR-340-5p functions in SAH.

METHODS

An experimental mouse model with SAH was established by the intravascular perforation, and the in vitro SAH model was constructed by exposing cocultured primary neurons and microglia to oxyhemoglobin. After overexpression of miR-340-5p in mice, the neurobehavioral disorders were evaluated by Garcia test; brain edema was evaluated by wet-dry method; blood-brain barrier (BBB) damage was detected with Evan's blue staining; levels of inflammatory cytokines were detected with enzyme-linked immunosorbent assay. After miR-340-5p was transfected in to microglia, Iba-1 expression was detected by Western blot, and neuronal apoptosis were detected with flow cytometry. The targeting relationship between miR-340-5p and STING was verified by dual-luciferase reporter gene assay and RNA immunoprecipitation assay.

RESULTS

MiR-340-5p was significantly inhibited in the brain tissues of mice with SAH and microglia of SAH model, and neurological impairment, brain edema, BBB injury, and neuroinflammation were significantly alleviated in mice after overexpressing miR-340-5p. STING was identified as a target of miR-340-5p, and STING overexpression could counteract the effects of miR-340-5p overexpression on neurons.

CONCLUSION

MiR-340-5p can attenuate EBI caused by SAH-induced neuroinflammation by inhibiting STING.

miR-141-3p protects against blood-brain barrier disruption and brain injury after intracerebral hemorrhage by targeting ZEB2

MicroRNAs (miRNAs) participate in the diagnosis and treatment of intracerebral hemorrhage (ICH). miR-141-3p has been widely reported to regulate neurological disorders and cerebropathy. However, the specific role of miR-141-3p in ICH has not yet been revealed. The aim of this study was exploration of the biological functions and mechanism of miR-141-3p in ICH by establishing a collagenase-induced ICH mouse model. After ICH induction, miR-141-3p mimics or miR-NC were administered into the right striatum of the model mice followed by the performance of neurological tests. After euthanasia of the mice, the injury volume, brain water content, and injury to the blood-brain barrier (BBB) were evaluated. Evans blue (EB) was used to stain the brain slices, and EB extravasation was detected to evaluate the injury to BBB. miR-141-3p expression in perihematomal edema and hematoma areas after ICH was assessed by RT-qPCR. The levels of tight junction proteins in brain tissues and human brain microvascular endothelial cells (BMECs) were evaluated by western blotting. The FITC-dextran 20 method was used to assess BMEC permeability. The binding between miR-141-3p and zinc finger E-box-binding homeobox 2 (ZEB2) was verified with a luciferase reporter assay. In this study, miR-141-3p overexpression alleviated ICH-induced brain injury and protected BBB integrity in vivo. ZEB2 was a target gene of miR-141-3p. ZEB2 overexpression promoted BBB disruption, and miR-141-3p overexpression attenuated the promoting effect exerted by ZEB2. Overall, miR-141-3p protects against BBB disruption and attenuates brain injuries induced by ICH by targeting ZEB2.

hsa-miR-340-5p inhibits epithelial–mesenchymal transition in endometriosis by targeting MAP3K2 and inactivating MAPK/ERK signaling

Increasing evidence has verified the indispensable effect of microRNAs (miRNAs) in the biological processes of human diseases, including endometriosis. hsa-miR-340-5p was reported to display a low level in patients with endometriosis, but the detailed function of miR-340-5p in endometriosis is unclarified. RT-qPCR was used for the assessment of RNA levels of miR-340-5p and its downstream target genes in endometrial stromal cells (ESCs). Western blotting and Transwell assays revealed that upregulation of miR-340-5p suppressed the migration, invasiveness, and epithelial–mesenchymal transition (EMT) in ESCs. Bioinformatics tools were used to predict miR-340-5p downstream genes. Luciferase reporter assay displayed that miR-340-5p could bind to messenger RNA mitogen-activated protein kinase kinase kinase 2 (MAP3K2). MAP3K2 was targeted by miR-349-5p and could reverse the influence of miR-340-5p. miR-340-5p exerted its impact on the invasive characters of ESCs by inactivating the MAP3K2-mediated MAPK/ERK signaling. In conclusion, miR-340-5p restrains cell migration, invasiveness, and EMT in ESCs by targeting MAP3K2 and inactivating MAPK/ERK signaling.

Influence of age and sex on microRNA response and recovery in the hippocampus following sepsis

Sepsis, defined as a dysregulated host immune response to infection, is a common and dangerous clinical syndrome. The excessive host inflammatory response can induce immediate and persistent cognitive decline, which can be worse in older individuals. Sex-specific differences in the outcome of infectious diseases and sepsis appear to favor females. We employed a murine model to examine the influence of age and sex on the brain's microRNA (miR) response following sepsis. Young and old mice of both sexes underwent cecal ligation and puncture (CLP) with daily restraint stress. Expression of hippocampal miR was examined in age- and sex-matched controls at 1 and 4 days post-CLP. Few miR were modified in a similar manner across age or sex and these few miR were generally associated with neuroprotection against inflammation. Similar to previous work examining transcription, young females exhibited a better recovery of the miR profile from day 1 to day 4, relative to young males and old females. For young males and all female groups, the initial response mainly involved a decrease in miR expression. In contrast, old males exhibited only upregulated miR on day 1 and day 4 and many of the miR upregulated on day 1 and day 4 were linked to neurodegeneration, increased neuroinflammation, and cognitive impairment. The results emphasize age and sex differences in epigenetic mechanisms that likely contribute to susceptibility or resilience to cognitive impairment due to sepsis.

MiR-340-5p inhibits Müller cell activation and pro-inflammatory cytokine production by targeting BMP4 in experimental diabetic retinopathy

Diabetic retinopathy (DR) is a disease that can cause blindness. Bone morphogenetic protein-4 (BMP4) was reported be overexpressed in DR model. However, the specific mechanism of BMP4 in DR development has not been explored. MiR-340-5p and BMP4 levels were detected by RT-qPCR in MIO-M1 cells and retinas of mice. Western blot analysis was used to examine GFAP, BMP4 and BRB junction protein levels. Inflammatory cytokine secretion and the retina structure were examined by ELISA and H&E staining, respectively. The interaction between miR-340-5p and BMP4 was identified by luciferase reporter assay. In HG-stimulated MIO-M1 cells, BMP4 was upregulated. Mechanically, BMP4 was targeted by miR-340-5p and negatively regulated by miR-340-5p. In rescue assays, BMP4 countervailed the suppressive effects of miR-340-5p on activation of Müller cells and release of inflammatory cytokines. Additionally, miR-18a-3p overexpression alleviated BRB injury to inhibit DR progression in vivo. In conclusion, miR-340-5p inhibits DR progression by targeting BMP4, which may offer a new pathway for treatment of DR.

Extracellular vesicles derived from bone marrow mesenchymal stem cells alleviate neuroinflammation after diabetic intracerebral hemorrhage via the miR-183-5p/PDCD4/NLRP3 pathway

OBJECTIVES

Intracerebral hemorrhage (ICH) induced by diabetes results in further brain injury and nerve cell death. Bone marrow mesenchymal stem cell (BMSC) transplantation contributes to attenuating neurological deficits after ICH. This study investigated the mechanism of extracellular vesicles (EVs) derived from BMSCs in reducing neuroinflammation after diabetic ICH.

METHODS

BMSC-EVs were isolated and identified. The rat model of db/db-ICH was established and the model rats were administered with EVs. miR-183-5p expression in brain tissues of db/db-ICH rats was detected. The brain injury of db/db-ICH rats was evaluated by measuring neurobehavioral score, brain water content and inflammatory factors. BV2 cells were cultured in vitro to establish high-glucose (HG)-Hemin-BV2 cell model. The levels of reactive oxygen species (ROS) and inflammatory factors in BV2 cells were measured, and BV2 cell viability and apoptosis were assessed. The targeting relationship between miR-183-5p and PDCD4 was predicted and verified. The activation of PDCD4/NLRP3 pathway in rat brain tissues and BV2 cells was detected.

RESULTS

miR-183-5p expression was reduced in db/db-ICH rats brain tissues. BMSC-EVs ameliorated cranial nerve function, decreased brain water content and repressed inflammatory response by carrying miR-183-5p. BMSC-EVs mitigated HG-Hemin-BV2 cell injury, reduced ROS level and suppressed inflammatory response. miR-183-5p targeted PDCD4. PDCD4 promoted BV2 cell inflammation by activating the NLRP3 pathway. BMSC-EVs inhibited HG-Hemin-BV2 cell inflammation through the miR-183-5p/PDCD4/NLRP3 pathway, and inhibition of miR-183-5p reversed the protective effect of EVs.

CONCLUSION

BMSC-EVs carried miR-183-5p into db/db-ICH rat brain tissues and repressed the NLRP3 pathway by targeting PDCD4, thus alleviating neuroinflammation after diabetic ICH.

The Assessment of Selected miRNA Profile in Familial Mediterranean Fever

Familial Mediterranean fever (FMF) is the most prevalent autoinflammatory disease. Typical findings are recurrent fever attacks with serositis, skin rash, and synovitis. FMF is caused by mutations in the MEFV gene, encoding pyrin protein. Pyrin functions in innate immunity and triggers inflammation via inflammatory mediators' production and acts as the primary regulatory component of the inflammasome. On the other hand, various miRNAs play crucial roles in the pathogenesis of different types of cancers and immune-related and neurodegenerative diseases. However, their association with FMF is still unclear. Therefore, in this study, we assessed the roles of selected thirteen miRNAs associated with immune functions. We recruited genetically diagnosed 28 FMF patients and 28 healthy individuals. The expression profiling of the miRNAs was determined by qRT-PCR and normalized to SNORD61. Our analysis revealed that miR-34a-5p, miR-142-3p, miR-216a-5p, miR-340-5p, miR-429, and miR-582-5p were upregulated, whereas miR-107, miR-569, and miR-1304-5p were downregulated in the FMF patients. Among them, miR-107 was found to be the most remarkable in M694V homozygous mutants compared to other homozygous mutants. During clinical follow-up of the patients with M694V mutation, which is closely related to amyloidosis, evaluation of mir-107 expression might be crucial and suggestive. Our results showed that miRNAs might serve a function in the pathogenesis of FMF. Further studies may provide novel and effective diagnostic and therapeutic agents that target examined miRNAs. Targeting miRNAs in FMF seems to be promising and may yield a new generation of rational therapeutics and diagnostic or monitoring tools enabling FMF treatment.

Mechanism of Baicalein in Brain Injury After Intracerebral Hemorrhage by Inhibiting the ROS/NLRP3 Inflammasome Pathway

Intracerebral hemorrhage (ICH) is a devastating subtype of stroke with high disability/mortality. Baicalein has strong anti-inflammatory activity. This study aims to explore the mechanism of baicalein on brain injury after ICH. The model of brain injury after ICH was established by collagenase induction, followed by the evaluation of neurological severity, brain water content, the degenerated neurons, neuronal apoptosis, and reactive oxygen species (ROS). The ICH model was treated with baicalein or silencing NLRP3 to detect brain injury. The expression of NLRP3 inflammasome was detected after treatment with ROS scavenger. The expressions of oxidative stress markers and inflammatory factors were detected, and the levels of components in NLRP3 inflammasome were detected. Baicalein reduced the damage of nervous system, lesion surface, brain water content, and apoptosis. Baicalein inhibited malondialdehyde and increased IL-10 by inhibiting ROS in brain tissue after ICH. Baicalein inhibited the high expression of NLRP3 inflammasome in ICH. ROS scavenger inhibited the NLRP3 inflammatory response by inhibiting ROS levels. Silencing NLRP3 alleviated the brain injury after ICH by inhibiting excessive oxidative stress and inflammatory factors. Overall, baicalein alleviated the brain injury after ICH by inhibiting ROS and NLRP3 inflammasome.