Inhibition of LncRNA MALAT1 Attenuates Cerebral Ischemic Reperfusion Injury via Regulating AQP4 Expression

STIM2 Suppression Blocks Glial Activation to Alleviate Brain Ischemia Reperfusion Injury via Inhibition of Inflammation and Pyroptosis

Cerebral ischemia/reperfusion injury (CIRI) involves various pathogenic mechanisms, including cytotoxicity, apoptosis, inflammation, and pyroptosis. Stromal interactive molecule 2 (STIM2) is implicated in cerebral ischemia. Consequently, this study investigates the biological functions of STIM2 and its related mechanisms in CIRI progression. Middle cerebral artery occlusion/reperfusion (MCAO/R) mouse models and oxygen-glucose deprivation/reoxygenation (OGD/R) cellular models were established. STIM2 level was upregulated in experimental CIRI models, as shown by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blotting and immunofluorescence staining. Brain infarction and edema were attenuated by STIM2 knockdown, as 2,3,5-triphenyltetrazolium chloride (TTC) staining and brain water content evaluation revealed. STIM2 knockdown relieved neuronal apoptosis, microglia activation, inflammation and pyroptosis in MCAO/R mice, as detected by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining, enzyme-linked immunosorbent assay (ELISA) and western blotting. Results of flow cytometry, ELISA, western blotting and cell counting kit-8 (CCK-8) assays also showed that STIM2 knockdown inhibited inflammation, apoptosis and pyroptosis in OGD/R-treated BV2 cells. Moreover, STIM2 knockdown inhibited apoptosis and pyroptosis in PC12 cells incubated with conditioned medium collected from OGD/R-exposed BV2 cells. Mechanistically, lncRNA Malat1 (metastasis associated lung adenocarcinoma transcript 1) positively regulated STIM2 expression by sponging miR-30d-5p. Their binding relationship was confirmed by luciferase reporter assays. Finally, lncRNA Malat1 elevation or miR-30d-5p knockdown abolished the sh-STIM2-induced inhibition in cell damage. In conclusion, STIM2 knockdown in microglia alleviates CIRI by inhibiting microglial activation, inflammation, apoptosis, and pyroptosis.

Non-coding RNAs and Aquaporin 4: Their Role in the Pathogenesis of Neurological Disorders

Neurological disorders are a major group of non-communicable diseases affecting quality of life. Non-Coding RNAs (ncRNAs) have an important role in the etiology of neurological disorders. In studies on the genesis of neurological diseases, aquaporin 4 (AQP4) expression and activity have both been linked to ncRNAs. The upregulation or downregulation of several ncRNAs leads to neurological disorder progression by targeting AQP4. The role of ncRNAs and AQP4 in neurological disorders is discussed in this review.

Transcriptome profiling of skeletal muscles from Korean patients with Bethlem myopathy

Bethlem myopathy is one of the collagens VI-related muscular dystrophies caused by mutations in the collagen VI genes. The study was designed to analyze the gene expression profiles in the skeletal muscle of patients with Bethlem myopathy. Six skeletal muscle samples from 3 patients with Bethlem myopathy and 3 control subjects were analyzed by RNA-sequencing. 187 transcripts were significantly differentially expressed, with 157 upregulated and 30 downregulated transcripts in the Bethlem group. Particularly, 1 (microRNA-133b) was considerably upregulated, and 4 long intergenic non-protein coding RNAs, LINC01854, MBNL1-AS1, LINC02609, and LOC728975, were significantly downregulated. We categorized differentially expressed gene using Gene Ontology and showed that Bethlem myopathy is strongly associated with the organization of extracellular matrix (ECM). Kyoto Encyclopedia of Genes and Genomes pathway enrichment reflected themes with significant enrichment of the ECM-receptor interaction (hsa04512), complement and coagulation cascades (hsa04610), and focal adhesion (hsa04510). We confirmed that Bethlem myopathy is strongly associated with the organization of ECM and the wound healing process. Our results demonstrate transcriptome profiling of Bethlem myopathy, and provide new insights into the path mechanism of Bethlem myopathy associated with non-protein coding RNAs.

An update on the functional roles of long non‑coding RNAs in ischemic injury (Review)

Ischemic injuries result from ischemia and hypoxia in cells. Tissues and organs receive an insufficient supply of nutrients and accumulate metabolic waste, which leads to the development of inflammation, fibrosis and a series of other issues. Ischemic injuries in the brain, heart, kidneys, lungs and other organs can cause severe adverse effects. Acute renal ischemia induces acute renal failure, heart ischemia induces myocardial infarction and cerebral ischemia induces cerebrovascular accidents, leading to loss of movement, consciousness and possibly, life-threatening disabilities. Existing evidence suggests that long non-coding RNAs (lncRNAs) are regulatory sequences involved in transcription, post-transcription, epigenetic regulation and multiple physiological processes. lncRNAs have been shown to be differentially expressed following ischemic injury, with the severity of the ischemic injury being affected by the upregulation or downregulation of certain types of lncRNA. The present review article provides an extensive summary of the functional roles of lncRNAs in ischemic injury, with a focus on the brain, heart, kidneys and lungs. The present review mainly summarizes the functional roles of lncRNA MALAT1, lncRNA MEG3, lncRNA H19, lncRNA TUG1, lncRNA NEAT1, lncRNA AK139328 and lncRNA CAREL, among which lncRNA MALAT1, in particular, plays a crucial role in ischemic injury and is currently a hot research topic.

Teriparatide induces angiogenesis in ischemic cerebral infarction zones of rats through AC/PKA signaling and reduces ischemia-reperfusion injury

Teriparatide is a commonly used drug indicated for the treatment of osteoporosis in postmenopausal women. Teriparatide can also upregulate Ang-1 expression through the AC/PKA signaling pathway to promote angiogenesis. At present, promoting angiogenesis is a promising but unrealized strategy for the treatment of ischemic cerebral infarction. However, there are few studies on the application of teriparatide in the treatment of cerebral infarction. We used teriparatide to treat ischemic cerebral infarction in rats and obtained three major findings. First, teriparatide can promote angiogenesis, reduce cerebral infarct size, and increase cerebral perfusion by upregulating Ang-1 expression. Second, teriparatide can promote the expression of HO1, SOD2 and inhibit the production of pro-inflammatory cytokines IL-1β, IL-6 by upregulating Nrf2 expression. Third, we further found that teriparatide can mitigate blood-brain barrier disruption and brain edema by downregulating the expressions of MMP9, Ang-2 and AQP4. Our results indicate that teriparatide is neuroprotective through multiple mechanisms of action that include promoting angiogenesis, inhibiting oxidative stress and neuroinflammation, protecting blood-brain barrier, and reducing brain edema.

Noncoding RNA crosstalk in brain health and diseases

The mammalian brain expresses several classes of noncoding RNAs (ncRNAs), including long ncRNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs). These ncRNAs play vital roles in regulating cellular processes by RNA/protein scaffolding, sponging and epigenetic modifications during the pathophysiological conditions, thereby controlling transcription and translation. Some of these functions are the result of crosstalk between ncRNAs to form a competitive endogenous RNA network. These intricately organized networks comprise lncRNA/miRNA, circRNA/miRNA, or lncRNA/miRNA/circRNA, leading to crosstalk between coding and ncRNAs through miRNAs. The miRNA response elements predominantly mediate the ncRNA crosstalk to buffer the miRNAs and thereby fine-tune and counterbalance the genomic changes and regulate neuronal plasticity, synaptogenesis and neuronal differentiation. The perturbed levels and interactions of the ncRNAs could lead to pathologic events like apoptosis and inflammation. Although the regulatory landscape of the ncRNA crosstalk is still evolving, some well-known examples such as lncRNA Malat1 sponging miR-145, circRNA CDR1as sponging miR-7, and lncRNA Cyrano and the circRNA CDR1as regulating miR-7, has been shown to affect brain function. The ability to manipulate these networks is crucial in determining the functional outcome of central nervous system (CNS) pathologies. The focus of this review is to highlights the interactions and crosstalk of these networks in regulating pathophysiologic CNS function.

Long Noncoding RNA X-Inactive Specific Transcript Regulates Neuronal Cell Apoptosis in Ischemic Stroke Through miR-98/BACH1 Axis

Long noncoding RNA X-inactive specific transcript (XIST) has been identified as a crucial regulator in neurodegenerative disorders. However, the role and mechanism of XIST in ischemic stroke remain elusive. In our study, we found that XIST expression was upregulated in both mice subjected to middle cerebral artery occlusion and oxygen-glucose deprivation (OGD)-treated neurons. Functional assays disclosed that the interference of XIST accelerated viability, and suppressed apoptosis and caspase-3 activity in OGD-treated neurons. Moreover, XIST interacted with miR-98, and miR-98 targeted BTB-to-CNC homology 1 (BACH1). miR-98 silencing or BACH1 overexpression counteracted XIST knockdown-mediated effects on cell viability and apoptosis in OGD-treated neurons. In conclusion, our data demonstrated that XIST facilitated the progression of ischemic stroke through regulating the miR-98/BACH1 axis. These findings might provide a novel therapeutic strategy for ischemic stroke treatment.