Overexpression of miR-217-5p protects against oxygen-glucose deprivation/reperfusion-induced neuronal injury via inhibition of PTEN

Neuronal Responses to Ischemia: Scoping Review of Insights from Human-Derived In Vitro Models

Translation of neuroprotective treatment effects from experimental animal models to patients with cerebral ischemia has been challenging. Since pathophysiological processes may vary across species, an experimental model to clarify human-specific neuronal pathomechanisms may help. We conducted a scoping review of the literature on human neuronal in vitro models that have been used to study neuronal responses to ischemia or hypoxia, the parts of the pathophysiological cascade that have been investigated in those models, and evidence on effects of interventions. We included 147 studies on four different human neuronal models. The majority of the studies (132/147) was conducted in SH-SY5Y cells, which is a cancerous cell line derived from a single neuroblastoma patient. Of these, 119/132 used undifferentiated SH-SY5Y cells, that lack many neuronal characteristics. Two studies used healthy human induced pluripotent stem cell derived neuronal networks. Most studies used microscopic measures and established hypoxia induced cell death, oxidative stress, or inflammation. Only one study investigated the effect of hypoxia on neuronal network functionality using micro-electrode arrays. Treatment targets included oxidative stress, inflammation, cell death, and neuronal network stimulation. We discuss (dis)advantages of the various model systems and propose future perspectives for research into human neuronal responses to ischemia or hypoxia.

miR-181a targets PTEN to mediate the neuronal injury caused by oxygen-glucose deprivation and reoxygenation

Evidence suggests that the microRNA-181 (miR-181) family performs various roles in the pathophysiology of cerebral ischemia and reperfusion injury (CIRI). MiR-181a has been identified as a critical determinant of neuronal survival. Moreover, the significance of miR-181a in controlling neuronal death after CIRI has received little attention. The objective of this study was to assess the role of miR-181a in neuronal cell injury after CIRI. To mimic the in-vitro and in-vivo CIRI, we developed an oxygen-glucose deficiency/reoxygenation (OGD/R) model in SH-SY5Y cells and a transient middle cerebral artery occlusion model in rats. MiR-181a expression was significantly higher in both in-vivo and in-vitro CIRI models. The overexpression of miR-181a increased cell damage and oxidative stress caused by OGD/R, whereas inhibition of miR-181a reduced both. PTEN has also been found to be a direct miR-181a target. PTEN overexpression reduced cell apoptosis and oxidative stress induced by miR-181a upregulation under an OGD/R condition. Furthermore, we found that the rs322931 A allele was related to increased miR-181a levels in IS peripheral blood and higher susceptibility to IS. The current results offer new insights into the understanding of the molecular pathophysiology of CIRI, as well as possible new treatment candidates.

Detection value of FOXO1 gene methylation, blood glucose and lipids in patients with type 2 diabetic kidney disease

Forkhead transcription factor O1 (FOXO1) methylation is associated with inflammation. Diabetic kidney disease (DKD) is characterized with increased inflammatory markers such as uric acid, hemogram indices, C-reactive protein derived markers, omentin and neuregulin. This study aimed to investigate the effect of DNA methylation in FOXO1 gene promoter, blood glucose and lipids in the process of type 2 DKD. Bisulfite genomic sequencing was used to monitor DNA methylation in the promoter region (+1021, +1193) of FOXO1 gene. The detections were taken in glycosylated hemoglobin A1c, fasting plasma glucose and blood lipid. 81 participants were divided into the control group, the preliminary diabetes mellitus group, the pure diabetes mellitus group, and the DKD group. The other groups displayed higher fasting plasma glucose than the control group (all P value < .05). The fasting plasma glucose level was higher in the pure diabetes mellitus group than the preliminary diabetes mellitus group (P = .004). The levels of HbA1c were higher in other groups than control group and preliminary diabetes mellitus groups (all P values < .01). The high-density lipoprotein level was lower in the DKD group (P = .021, P = .022) than control and pure diabetes mellitus group. The levels of low-density lipoprotein were statistically lower in preliminary diabetes mellitus and DKD groups than control group (all P value < .02). Along with the progress of DKD, a down trend was observed in the total methylation rate of FOXO1 gene (P = .025), which contains 5 CpG sites (1021, +1193) in the promoter. Hypomethylation in the promoter of FOXO1 gene, hyperglycemia and low level of serum lipid might be associated with the pathogenesis of type 2 DKD.

Salidroside alleviates severe acute pancreatitis-triggered pancreatic injury and inflammation by regulating miR-217-5p/YAF2 axis

BACKGROUND

Our previous studies have shown that salidroside (Sal) exerted a protective effect in severe acute pancreatitis (SAP) via inhibiting the inflammatory response. However, the molecular mechanism has not been fully elucidated.

METHODS

Using SAP rat model and miRNA microarray, the effect of Sal on miRNA expression profiling was determined and then validated their changes by quantitative Real-time PCR (qRT-PCR). Then, SAP cell model, enzyme-linked immunosorbent assay (ELISA) and Cell Counting Kit-8 (CCK-8) assay were used to explore the biological function of miR-217-5p in vitro. Bioinformatics analysis, luciferase reporter assay and miRNA pulldown assay were performed to investigate the underlying mechanism of miR-217-5p in the protection of Sal against SAP.

RESULTS

Compared with SAP group, 21 differentially expressed miRNAs were identified in SAP + Sal group. The target genes of these miRNAs were strongly associated with regulation of transcription, Axon guidance, Pathways in cancer and MAPK signaling pathway. Among these miRNAs, miR-217-5p was the most downregulated miRNA. Sal treatment alleviated cell injury and reduced the production of pro-inflammatory cytokines. Whereas overexpression of miR-217-5p reversed the effects of Sal. We identified YY1 associated factor 2 (YAF2) as a direct target gene of miR-217-5p and Sal treatment could upregulate YAF2 expression via targeting miR-217-5p. Furthermore, knockdown of YAF2 counteracted Sal-induced alleviation of cell injury and inflammation. Moreover, Sal could suppress the activation of p38 MAPK pathway by regulating miR-217-5p/YAF2 axis.

CONCLUSIONS

Our findings for the first time highlighted that Sal alleviated pancreatic injury and inhibited inflammation by regulating miR-217-5p/YAF2 axis, which might provide new therapeutic strategies for SAP treatment.

Neuronal Death Mechanisms and Therapeutic Strategy in Ischemic Stroke

Ischemic stroke caused by intracranial vascular occlusion has become increasingly prevalent with considerable mortality and disability, which gravely burdens the global economy. Current relatively effective clinical treatments are limited to intravenous alteplase and thrombectomy. Even so, patients still benefit little due to the short therapeutic window and the risk of ischemia/reperfusion injury. It is therefore urgent to figure out the neuronal death mechanisms following ischemic stroke in order to develop new neuroprotective strategies. Regarding the pathogenesis, multiple pathological events trigger the activation of cell death pathways. Particular attention should be devoted to excitotoxicity, oxidative stress, and inflammatory responses. Thus, in this article, we first review the principal mechanisms underlying neuronal death mediated by these significant events, such as intrinsic and extrinsic apoptosis, ferroptosis, parthanatos, pyroptosis, necroptosis, and autophagic cell death. Then, we further discuss the possibility of interventions targeting these pathological events and summarize the present pharmacological achievements.

Role of Forkhead Box Protein O1 (FoxO1) in Stroke: A Literature Review

Stroke is one of the most prevalent causes of death around the world. When a stroke occurs, many cellular signaling cascades and regulators are activated, which results in severe cellular dysfunction and debilitating long-term disability. One crucial regulator of cell fate and function is mammalian Forkhead box protein O1 (FoxO1). Many studies have found FoxO1 to be implicated in many cellular processes, including regulating gluconeogenesis and glycogenolysis. During a stroke, modifications of FoxO1 have been linked to a variety of functions, such as inducing cell death and inflammation, inhibiting oxidative injury, affecting the blood brain barrier (BBB), and regulating hepatic gluconeogenesis. For these functions of FoxO1, different measures and treatments were applied to FoxO1 after ischemia. However, the subtle mechanisms of post-transcriptional modification and the role of FoxO1 are still elusive and even contradictory in the development of stroke. The determination of these mechanisms will lead to further enlightenment for FoxO1 signal transduction and the identification of targeted drugs. The regulation and function of FoxO1 may provide an important way for the prevention and treatment of diseases. Overall, the functions of FoxO1 are multifactorial, and this paper will summarize all of the significant pathways in which FoxO1 plays an important role during stroke damage and recovery.

Identification and coregulation pattern analysis of long noncoding RNAs following subacute spinal cord injury

Long noncoding RNAs (lncRNAs) have been demonstrated to play critical regulatory roles in posttranscriptional and transcriptional regulation in eukaryotic cells. However, the characteristics of many lncRNAs, particularly their expression patterns in the lesion epicenter of spinal tissues following subacute spinal cord injury (SCI), remain unclear. In this study, we determined the expression profiles of lncRNAs in the lesion epicenter of spinal tissues after traumatic SCI and predicted latent regulatory networks. Standard Allen's drop surgery was conducted on mice, and hematoxylin and eosin staining was used to observe the damaged area. High-throughput sequencing was performed to identify the differential expression profiles of lncRNAs. Quantitative real-time polymerase chain reaction was conducted to evaluate the quality of the sequencing results. Bioinformatics analyses, including Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis, coexpression analysis, and protein-protein interaction analysis, were performed. Targeted binding of lncRNA-miRNA-mRNA was predicted by TargetScan and miRanda. A total of 230 differentially expressed lncRNAs were identified and preliminarily verified, and some potential regulatory networks were constructed. These findings improve our understanding of the mechanisms underlying subacute SCI; differentially expressed lncRNAs are closely involved in pathophysiological processes by regulating multiple pathways. Further studies are essential for revealing the exact mechanism underlying competing endogenous RNA pathways in vivo and in vitro.

Knockdown of circHECTD1 inhibits oxygen-glucose deprivation and reperfusion induced endothelial-mesenchymal transition

Ischemic stroke (IS) has become a cerebrovascular disease which seriously threatens the elderly people. It has been reported that circRNAs participate in multiple diseases, including IS. However, the role of circHECTD1 in IS remains largely unknown. To mimic IS in vitro, human cerebral microvascular endothelial cells (HCMECs) were treated with oxygen glucose deprivation/reperfusion (OGD/R). Meanwhile, MCAO mouse model was established to detect the expression of circHECTD1 in IS. qRT-PCR and western blot were used to test gene and protein expressions, respectively. CCK-8 assay was used to investigate the cell viability. Moreover, cell migration and tube formation were assessed by transwell and tube formation assays. In addition, RIP and luciferase assay were performed to explore the association among circHECTD1, miR-335 and NOTCH2. CircHECTD1 was significantly upregulated in IS. OGD/R significantly induced EndoMT in HCMECs, while knockdown of circHECTD1 notably reversed this phenomenon. In addition, silencing of circHECTD1 remarkably reversed OGD/R-induced promotion of HCMEC tube formation and migration. Meanwhile, circHECTD1 upregulated the level of NOTCH2 through binding with miR-335. Furthermore, miR-335 inhibited the process of EndoMT in IS via targeting NOTCH2. In summary, circHECTD1 knockdown significantly alleviated EndoMT process in HCMECs via mediation of miR-335/NOTCH2 axis. Thus, circHECTD1 might act as a potential target against IS.

Recombinant protein Schistosoma japonicum-derived molecule attenuates dextran sulfate sodium-induced colitis by inhibiting miRNA-217-5p to alleviate apoptosis

BACKGROUND

Inflammatory bowel disease (IBD) affects millions of people worldwide and has emerged as a growing problem in industrialized nations. The lack of therapeutic targets has limited the treatment of IBD. Studies found that parasitic nematode infections can ameliorate clinical and experimental colitis. Our previous study found that rSj16, a 16-kDa secreted protein of Schistosoma japonicum produced by Escherichia coli, has protective effects on dextran sulfate sodium (DSS)-induced colitis in mice. Apoptosis is an important factor in the pathogenesis of colitis. However, it is not clear whether the effect of rSj16 on colitis is related to apoptosis.

AIM

To investigate whether the protective effects of rSj16 on colitis is related to apoptosis and its mechanism.

METHODS

In-vivo, colitis was induced by DSS. The severity of colitis was assessed. WB was used to detect the changes of apoptosis-related genes in colon tissues. Q-PCR was used to detect the changes of miRNA-217-5p and HNF1B. In-vitro, WB was used to detect the changes of apoptosis-related genes in intestinal epithelial cells. TUNNEL staining and flow cytometry were used to detect cell apoptosis.

RESULTS

rSj16 attenuates clinical activity in DSS-induced colitis mice. TUNNEL staining and WB results showed that apoptosis was increased in colon tissue after treatment with DSS, and the apoptosis of colon tissue was significantly reduced after treatment with rSj16. Compared with normal mice, the expression of miR-217-5p was increased in colon tissue of DSS-induced colitis mice. In addition, the miR-217-5p target gene hnf1b was decreased after administration of DSS. After treatment with rSj16, the expression of miR-217-5p was decreased and the expression of HNF1B was increased compared with the DSS-treated group. When Etoposide was used in combination with miR-217-5p mimic on MODE-K cells, the expression of cleaved-Caspase-3 and Bax was increased, and Bcl-2 was decreased compared with only Etoposide treatment, the expression of HNF1B was significantly reduced, suggesting that miR-217-5p acts as a pro-apoptotic in colon epithelial cells and down-regulates the target gene hnf1b. After rSj16 administration in MODE-K cells, miR-217-5p expression was significantly decreased, HNF1B expression was increased, and apoptosis was reduced.

CONCLUSION

The protective effects of rSj16 on colitis is related to apoptosis and miRNA-217-5p may be a further target for therapeutic intervention against IBD.

MiR-361-5p promotes oxygen-glucose deprivation/re-oxygenation induced neuronal injury by negatively regulating SQSTM1 in vitro

It has been reported that microRNAs (miRNAs) play essential roles in cerebral ischemia and reperfusion (I/R) injury. This study aimed to explore the role of miR-361-5p in oxygen-glucose deprivation/re-oxygenation-induced neuronal injury in vitro. Cerebral I/R injury cell model was established by using PC12 cells exposed to oxygen-glucose deprivation/re-oxygenation (OGD/R). The expression of miR-361-5p and SQSTM1 was evaluated by qRT-PCR or western blot. Neuronal apoptosis was detected by flow cytometry, and cell viability was assessed by CCK-8 assay. The effects of miR-361-5p on the release of LDH and the levels of MDA, SOD, and GSH-Px were investigated by respective detection kits. Dual-luciferase reporter assay and RIP assay were performed to determine the interaction between miR-361-5p and SQSTM1. Rescue experiments were performed to evaluate the function of miR-361-5p and SQSTM1. MiR-361-5p was significantly upregulated, and SQSTM1 was significantly downregulated in OGD/R-stimulated PC12 cells. MiR-361-5p could directly interact with SQSTM1 and negatively regulated it. Inhibition of miR-361-5p efficiently inhibited OGD/R-induced apoptosis and attenuated OGD/R-induced growth defect in PC12 cells. In addition, SQSTM1 overexpression partially attenuates the apoptosis and promoted the viability of OGD/R-treated PC12 cells, which were aggravated by miR-361-5p mimics. Our study demonstrated that miR-361-5p promotes OGD/R-induced neuronal injury via regulating SQSTM1 in PC12 cells.

CircDLGAP4 overexpression relieves oxygen-glucose deprivation-induced neuronal injury by elevating NEGR1 through sponging miR-503-3p

Circular RNAs (circRNAs) have been reported to play vital regulatory roles in human diseases. However, the functions of circRNAs in ischemic stroke (IS) are limited. In this study, we aimed to explore the functions and mechanisms of circRNA DLG associated protein 4 (circDLGAP4) in IS development. Oxygen-glucose deprivation (OGD)-treated HCN-2 cells were used to mimic IS environment in vitro. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was used to detect the levels of circDLGAP4, microRNA-503-3p (miR-503-3p) and neuronal growth regulator 1 (NEGR1) mRNA. RNase R assay was conducted to analyze the stability of circDLGAP4. Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis were adopted for cell viability and death, respectively. Western blot assay was performed for protein levels. Enzyme-linked immunosorbent assay (ELISA) kits were used to examine the concentrations of inflammatory cytokines. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull-down assay were employed to analyze the relationships among circDLGAP4, miR-503-3p and NEGR1. CircDLGAP4 level was declined in HCN-2 cells after OGD treatment. CircDLGAP4 overexpression promoted cell viability and suppressed cell death and inflammatory cytokine concentrations in OGD-treated HCN-2 cells. CircDLGAP4 acted as the sponge for miR-503-3p and the impacts of circDLGAP4 overexpression on cell viability, death and inflammation in OGD-treated HCN-2 cells were reversed by miR-503-3p elevation. Furthermore, NEGR1 was the target gene of miR-503-3p. MiR-503-3p inhibition ameliorated OGD-induced HCN-2 cell impairments, but NEGR1 knockdown abolished the effects. CircDLGAP4 alleviated OGD-induced HCN-2 cell damage by regulating miR-503-3p/NEGR1 axis.

RETRACTED: Knockdown EZH2 attenuates cerebral ischemia-reperfusion injury via regulating microRNA-30d-3p methylation and USP22

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief as there are concerns about the reliability of the results. Concerns have been raised about a portion of Figure 5B, ‘DMSO’ group appears to contain image similarities with Figure 4e, ‘Inhibitor NC’ group, published in Yang et al., 2021 doi: 10.1080/15384101.2020.1856498. A portion of Figure 5B, ‘DZNeP+miR-30d-3p antagomir’ group appears to contain image similarities with Figure 4e, ‘Inhibitor NC’ group, published in Yang et al., 2021. Figure 7/G western blot bands have the same eyebrow shaped phenotype as many other publications as detailed here (https://pubpeer.com/publications/B26AE47AC0E71E0EF339B40893B2C2).

Regulatory role of microRNAs on PTEN signaling

Phosphatase and tensin homolog (PTEN) gene encodes a tumor suppressor protein which is altered in several malignancies. This protein is a negative regulator of the PI3K/AKT signaling. Several transcription factors regulate the expression of PTEN in positive or negative directions. Moreover, numerous microRNAs (miRNAs) have functional interactions with PTEN and inhibit its expression. Suppression of PTEN can attenuate the response of cancer cells to chemotherapeutic agents. Based on the critical role of this tumor suppressor gene, the identification of negative regulators of its expression has practical significance particularly in the prevention and management of cancer. Meanwhile, the interaction between miRNAs and PTEN has functional consequences in non-malignant disorders including myocardial infarction, osteoporosis, cerebral ischemic stroke, and recurrent abortion. In the present review, we describe the role of miRNAs in the regulation of expression and activity of PTEN.