Shan Wang

MicroRNA‐140‐5p elevates cerebral protection of dexmedetomidine against hypoxic–ischaemic brain damage via the Wnt/β‐catenin signalling pathway

Hypoxia–ischaemia (HI) remains a major cause of foetal brain damage presented a scarcity of effective therapeutic approaches. Dexmedetomidine (DEX) and microRNA‐140‐5p (miR‐140‐5p) have been highlighted due to its potentially significant role in the treatment of cerebral ischaemia. This study was to investigate the role by which miR‐140‐5p provides cerebral protection using DEX to treat hypoxic–ischaemic brain damage (HIBD) in neonatal rats via the Wnt/β‐catenin signalling pathway. The HIBD rat models were established and allocated into various groups with different treatment plans, and eight SD rats into sham group. The learning and memory ability of the rats was assessed. Apoptosis and pathological changes in the hippocampus CA1 region and expressions of the related genes of the Wnt/β‐catenin signalling pathway as well as the genes responsible of apoptosis were detected. Compared with the sham group, the parameters of weight, length growth, weight ratio between hemispheres, the rate of reaching standard, as well as Bcl‐2 expressions, were all increased. Furthermore, observations of increased levels of cerebral infarction volume, total mortality rate, response times, total response duration, expressions of Wnt1, β‐catenin, TCF‐4, E‐cadherin, apoptosis rate of neurons, and Bax expression were elevated. Following DEX treatment, the symptoms exhibited by HIBD rats were ameliorated. miR‐140‐5p and si‐Wnt1 were noted to attenuate the progression of HIBD. Our study demonstrates that miR‐140‐5p promotes the cerebral protective effects of DEX against HIBD in neonatal rats by targeting the Wnt1 gene through via the negative regulation of the Wnt/β‐catenin signalling pathway.

Repression of microRNA-382 inhibits glomerular mesangial cell proliferation and extracellular matrix accumulation via FoxO1 in mice with diabetic nephropathy

Diabetic nephropathy (DN) is a nerve damaging disorder, characterized by glomerular mesangial cell expansion and accumulation of extracellular matrix (ECM) proteins. In this study, we aimed to investigate mesangial cell proliferation and ECM accumulation when promoting or suppressing endogenous miR‐382 in glomerular mesangial cells of DN.

Effects of CREB1 gene silencing on cognitive dysfunction by mediating PKA-CREB signaling pathway in mice with vascular dementia

BackgroundAs a form of dementia primarily affecting the elderly, vascular dementia (VD) is characterized by changes in the supply of blood to the brain, resulting in cognitive impairment. The aim of the present study was to explore the effects involved with cyclic adenosine monophosphate (cAMP) response element-binding (CREB)1 gene silencing on cognitive dysfunction through meditation of the protein kinase A (PKA)-CREB signaling pathway in mice with VD.MethodsBoth the Morris water maze test and the step down test were applied to assess the cognitive function of the mice with VD. Immunohistochemical and TUNEL staining techniques were employed to evaluate the positive expression rates of the protein CREB1 and Cleaved Caspase-3, as well as neuronal apoptosis among hippocampal tissues in a respective manner. Flow cytometry was applied to determine the proliferation index and apoptosis rate of the hippocampal cells among each group. Reverse transcription quantitative polymerase chain reaction and Western blot analysis methods were applied to detect the expressions of cAMP, PKA and CREB in hippocampal cells.ResultsCompared with the normal group, all the other groups exhibited impaired cognitive function, reduced cell numbers in the CAI area, positive expressions of CREB1 as well as positive optical density (OD) values. Furthermore, increased Cleaved Caspase-3 positive expression, OD value, proliferation index, apoptosis rate of hippocampal cells and neurons, were observed in the other groups when compared with the normal group, as well as lower expressions of cAMP, PKA and CREB1 and p-CREB1 (the shCREB1–1, H89 and shCREB1–1u2009+u2009H89 groups < the VD group).ConclusionThe key findings of the present study demonstrated that CREB1 gene silencing results in aggravated VD that occurs as a result of inhibiting the PKA-CREB signaling pathway, thus exasperating cognitive dysfunction.

Adeno-associated virus vector-mediated expression of DJ-1 attenuates learning and memory deficits in 2, 2´, 4, 4´-tetrabromodiphenyl ether (BDE-47)-treated mice

Evidence indicates that oxidative stress is the central pathological feature of 2, 2´, 4, 4´-tetrabromodiphenyl ether (BDE-47)-induced neurotoxicity. Protein kinase C delta (PKCδ), an oxidative stress-sensitive kinase, can be proteolytically cleaved to yield a catalytically active fragment (PKCδ-CF) that is involved in various neurodegenerative disorders. Here, we showed that BDE-47 treatment increased ROS, malondialdehyde, and protein carbonyl levels in the mouse hippocampus. In turn, excessive ROS induced caspase-3-dependent PKCδ activation and stimulated NF-κB p65 nuclear translocation, resulting in inflammation in the mouse hippocampus. These changes caused learning and memory deficits in BDE-47-treated mice. Treatment with Z-DEVD-fmk, a caspase-3 inhibitor, or N-acetyl-L-cysteine, an antioxidant, blocked PKCδ activation and subsequently inhibited inflammation, thereby improving learning and memory deficits in BDE-47-treated mice. Our data further showed that activation of ROS-PKCδ signaling was associated with DJ-1 downregulation, which exerted neuroprotective effects against oxidative stress induced by different neurotoxic agents. Adeno-associated viral vector-mediated DJ-1 overexpression in the hippocampus effectively inhibited excessive ROS production, suppressed caspase-3-dependent PKCδ cleavage, blunted inflammation and ultimately reversed learning and memory deficits in BDE-47-treated mice. Taken together, our results demonstrate that DJ-1 plays a pivotal role in BDE-47-induced neurotoxic effects and learning and memory deficits.

MircoRNA-1275 promotes proliferation, invasion and migration of glioma cells via SERPINE1

This study was designed to explore the relationship between miR‐1275 and SERPINE1 and its effects on glioma cell proliferation, migration, invasion and apoptosis. Differentially expressed miRNAs and mRNAs in glioma tissues were screened out by bioinformatic analysis. Dual‐luciferase reporter gene assay was used to validate the targeted relationship between miR‐1275 and SERPINE1. qRT‐PCR was used to detect the expression of miR‐1275 and SERPINE1 in glioma tissues. The expressions of SERPINE1 and p53 pathway‐related proteins in glioma cells were detected by western blot. Glioma cell proliferation, apoptosis, migration and invasion were respectively detected by CCK‐8 assay, flow cytometry, wound healing assay and transwell assay. Tumour xenograft model was developed to study the influence of miR‐1275 and SERPINE1 on glioma growth in vivo. The results of microarray analysis, qRT‐PCR and western blot showed that miR‐1275 was low‐expressed while SERPINE1 was high‐expressed in glioma. Dual‐luciferase assay showed that miR‐1275 could bind to SERPINE1. Overexpression of miR‐1275 could promote the p53 pathway‐related proteins’ expression. Highly expressed miR‐1275 could repress the migration, proliferation and invasion of glioma cells while highly expressed SERPINE1 had inverse effects. Tumour xenograft showed that up‐regulated miR‐1275 or down‐regulated SERPINE1 could repress glioma growth in vivo. Up‐regulation of miR‐1275 activated p53 signalling pathway via regulating SERPINE1 and therefore suppressed glioma cell proliferation, invasion and migration, whereas promoted cell apoptosis.

S100A9 gene silencing inhibits the release of pro-inflammatory cytokines by blocking the IL-17 signalling pathway in mice with acute pancreatitis

The study aimed to investigate whether S100A9 gene silencing mediating the IL‐17 pathway affected the release of pro‐inflammatory cytokines in acute pancreatitis (AP). Kunming mice were assigned to the normal, AP, AP + negative control (NC), AP + shRNA, AP + IgG and AP + anti IL‐17 groups. ELISA was applied to measure expressions of AMY, LDH, CRP, TNF‐α, IL‐6 and IL‐8. The cells were distributed into the control, blank, NC, shRNA1 and shRNA2 groups. MTT assay, flow cytometry, RT‐qPCR and Western blotting were used to evaluate cell proliferation, cell cycle and apoptosis, and expressions of S100A9, TLR4, RAGE, IL‐17, HMGB1 and S100A12 in tissues and cells. Compared with the normal group, the AP group displayed increased expressions of AMY, LDH, CRP, TNFα, IL‐6, IL‐8, S100A9, TLR4, RAGE, IL‐17, HMGB1 and S100A12. The AP + shRNA and AP + anti IL‐17 groups exhibited an opposite trend. The in vivo results: Compare with the control group, the blank, NC, shRNA1 and shRNA2 groups demonstrated increased expressions of S100A9, TLR4, RAGE, IL‐17, HMGB1 and S100A12, as well as cell apoptosis and cells at the G1 phase, with reduced proliferation. Compared with the blank and NC groups, the shRNA1 and shRNA2 groups had declined expressions of S100A9, TLR4, RAGE, IL‐17, HMGB1 and S100A12, as well as cell apoptosis and cells at the G1 phase, with elevated proliferation. The results indicated that S100A9 gene silencing suppressed the release of pro‐inflammatory cytokines through blocking of the IL‐17 pathway in AP.

MicroRNA-30d preserves pancreatic islet β-cell function through negative regulation of the JNK signaling pathway via SOCS3 in mice with streptozotocin-induced diabetes mellitus

The loss of pancreatic islet β‐cell function represents the classical feature in the pathogenesis of type 2 diabetes mellitus (T2DM). Previous evidence has highlighted the involvement of the activated JNK pathway in relation to islet β‐cell apoptosis. Hence, during the present study a streptozotocin‐induced DM mice model was established in a bid to ascertain as to whether microRNA‐30d (miR‐30d) plays a regulatory role in the JNK pathway in relation to islet β‐cell dysfunction. The collection and identification of the islet β cells from streptozotocin‐induced mice was performed. Islet β cells with elevated or suppressed levels of miR‐30 as well as knocked down SOCS3 were established in order to verify the regulatory mechanisms by which miR‐30d governs SOCS3 in vitro. We found miR‐30d was overexpressed among tissue samples obtained form streptozotocin‐induced mice and their islet β cells, as well as increasing miR‐30d expression when the JNK pathway was activated were found to promote islet β cell growth and cell cycle entry, and inhibit apoptosis. SOCS3, confirmed to be a miR‐30d target, was decreased in the islet β cells following the promotion of miR‐30d, while the JNK pathway was inhibited following SOCS3 knocdown. Furthermore, the effect of miR‐30d inhibition was lost in islet β cells when SOCS3 was knocked down. The data of the present study support the notion that miR‐30d‐mediated direct suppression of SOCS3 acts to protect pancreatic β‐cell functions through the JNK signaling pathway, emphasizing the potential of miR‐30d as a novel pharmacological target for treatment and intervention of DM.

Effect of microRNA-186 on oxidative stress injury of neuron by targeting interleukin 2 through the janus kinase-signal transducer and activator of transcription pathway in a rat model of Alzheimer’s disease: WU et al.

Recent studies have proposed that microRNAs (miR) function as novel diagnostic and prognostic biomarkers and therapeutic targets in Alzheimer’s disease (AD), a common disease among the elderly. In the current study, we aim to explore the effect of miR‐186 on oxidative stress injury of neuron in rat models of AD with the involvement of the interleukin‐2 (IL2) and the Janus kinase/signal transducers and activators of transcription (JAK–STAT) pathways. AD rat models were established, and dual‐luciferase reporter assay and online software were used to confirm the targeting relationship between miR‐186 and IL2. Immunohistochemistry was used evaluating the positive rate of IL2. Afterward, to define the role of miR‐186 in AD, miR‐186, IL2, and JAK–STAT related protein (JAK2, STAT3) expressions were quantified. Cell proliferation was measured by 3‐(4,5‐dimethylthiazol‐2‐yl)2,5‐diphenyl tetrazolium bromide, and cell apoptosis was detected by flow cytometry. We observed downregulated miR‐186 and IL2 and upregulated JAK–STAT signaling pathway related genes in AD. The overexpression of miR‐186 was shown to significantly promote cell proliferation while suppressing cell apoptosis along with the expression of the IL2 and JAK–STAT signaling pathway related protein. Collectively, the key findings obtained from the current study define the potential role of miR‐186 as an inhibitor of AD development by downregulation of IL2 through suppression of the JAK–STAT signaling pathway.

Suppression of microRNA-342-3p increases glutamate transporters and prevents dopaminergic neuron loss through activating the Wnt signaling pathway via p21-activated kinase 1 in mice with Parkinson's disease: WU et al.

Development of effective therapeutic drugs for Parkinsons disease (PD) is of great importance. Aberrant microRNA (miRNA) expression has been identified in postmortem human PD brain samples, in vitro and in vivo PD models. However, the role of miR‐342‐3p in PD has been understudied. The study explores the effects of miR‐342‐3p on expression of glutamate (Glu) transporter, and dopaminergic neuron apoptosis and proliferation by targeting p21‐activated kinase 1 (PAK1) through the Wnt signaling pathway in PD mice. After establishment of PD mouse models, gain‐ or loss‐of‐function assay was performed to explore the functional role of miR‐342‐3p in PD. Number of apoptotic neurons and Glu concentration was then determined. Subsequently, PC12 cells were treated with miR‐342‐3p mimic, miR‐342‐3p inhibitor, dickkopf‐1 (DKK1), and miR‐342‐3p inhibitoru2009+u2009DKK1. The expression of miR‐342‐3p, PAK1, the Wnt signaling pathway‐related and apoptosis‐related genes, Glutamate transporter subtype 1 (GLT‐1), l‐glutamate/ l‐aspartate transporter (GLAST), tyrosine hydroxylase (TH) was measured. Also, cell viability and apoptosis were evaluated. PD mice exhibited increased miR‐342‐3p, while decreased expression of PAK1, GLT‐1, GLAST, TH, and the Wnt signaling pathway‐related and antiapoptosis genes. miR‐342‐3p downregulation could promote expression of PAK1, the Wnt signaling pathway‐related and antiapoptosis genes. GLT‐1, GLAST, and TH as well as cell viability, but reduce cell apoptosis rate. The results indicated that suppression of miR‐342‐3p improves expression of Glu transporter and promotes dopaminergic neuron proliferation while suppressing apoptosis through the Wnt signaling pathway by targeting PAK1 in mice with PD.

MCL1 Gene Silencing Promotes Senescence and Apoptosis of Glioma Cells via Inhibition of the PI3K/Akt Signaling Pathway: MCL1 SILENCING & PI3K/Akt PATHWAY ON GLIOMA

Glioma is known to be the most prevalent primary brain tumor. In recent years, there has been evidence indicating myeloid cell leukemia‐1 (MCL1) plays a role in brain glioblastoma. Therefore, the present study was conducted with aims of exploring the ability of MCL1 silencing to influence glioma cell senescence and apoptosis through the mediation of the phosphatidylinositol 3‐kinase (PI3K)/protein kinase B (Akt) signaling pathway. Glioma and tumor‐adjacent tissues were collected in order to detect the presence of higher levels of MCL1 protein expression. Next, the mRNA and protein expression of MCL1, PI3K, Akt, B cell lymphoma 2 (Bcl2), Bcl2‐associated X (Bax), B lymphoma Mo‐MLV insertion region 1 homolog (Bmi‐1), and phosphatase and tensin homolog (PTEN) were determined. Cell counting kit‐8 assay was applied to detect cell proliferation, β‐galactosidase staining for cell senescence, and flow cytometry for cell cycle entry and apoptosis. Initially, the results revealed higher positive expression rate of MCL1 protein, increased mRNA and protein expression of MCL1, PI3K, Akt, Bmi‐1, and Bcl‐2 and decreased that of Bax and PTEN in human glioma tissues. The silencing of MCL1 resulted in a decrease in mRNA and protein expression of PI3K, Akt, Bmi‐1, and Bcl‐2 and an increase in Bax and PTEN expressions in glioma cells. Moreover, silencing of MCL1 also inhibited cell proliferation and cell cycle entry in glioma cells, and promoted glioma cell senescence and apoptosis. In conclusion, the aforementioned results collectively suggested that the silencing of MCL1 promotes senescence and apoptosis in glioma cells through inhibiting the PI3K/Akt signaling pathway. Thus, decreasing the expression of MCL1 might have therapeutic functions in glioma.