MicroRNA-379-5p targets MAP3K2 to reduce autophagy and alleviate neuronal injury following cerebral ischemia via the JNK/c-Jun signaling pathway.

MicroRNAs (miRNAs) are abundant in neurons and play key roles in the function and development of the nervous system. This study focuses on the function of miR-379-5p in neurological function recovery during ischemic stroke. The expression of miR-379-5p in the serum of patients with ischemic stroke was determined. Human cerebral cortical neuron cells (HCN-2) were subjected to oxygen/glucose deprivation (OGD) to mimic an ischemic stroke in vitro, whereas mice subjected to middle cerebral artery occlusion (MCAO) were used as an animal model. The serum of patients with ischemic stroke and OGD-treated HCN-2 cells displayed a poor expression of miR-379-5p. Upregulation of miR-379-5p reduced the OGD-induced cell damage and decreased the expression of the autophagy marker protein Beclin1 in cells. Rapamycin, an autophagy activator, blocked the protective functions of miR-379-5p. Further, miR-379-5p directly bound to MAP3K2. MAP3K2 activated the JNK/c-Jun signaling pathway and suppressed the neuroprotective events mediated by miR-379-5p. The in vitro results were reproduced in vivo, where upregulation of miR-379-5p reduced neurological impairment and infarct size in MCAO-induced mice. This study suggested that miR-379-5p showed a neuroprotective effect on ischemic stroke and reduced autophagy of neurons through the suppression of MAP3K2 and the JNK/c-Jun axis.

Ibrutinib ameliorates cerebral ischemia/reperfusion injury through autophagy activation and PI3K/Akt/mTOR signaling pathway in diabetic mice.

Bruton's tyrosine kinase (BTK) is involved in the diabetogenic process and cerebral ischemic injury. However, it remained unclear whether BTK inhibition has remedial effects on ischemia/reperfusion (I/R) injury complicated with diabetes. We aim to investigate the regulatory role and potential mechanism of ibrutinib, a selective inhibitor of BTK, in cerebral I/R injured diabetic mice. The cytotoxicity and cell vitality tests were performed to evaluate the toxic and protective effects of ibrutinib at different incubating concentrations on normal PC12 cells or which were exposed to high glucose for 24 h, followed by hypoxia and reoxygenation (H/R), respectively. Streptozotocin (STZ) stimulation-induced diabetic mice were subjected to 1 h ischemia and then reperfusion. Then the diabetic mice received different dosages of ibrutinib or vehicle immediately and 24 h after the middle cerebral artery occlusion (MCAO). The behavioral, histopathological, and molecular biological tests were then performed to demonstrate the neuroprotective effects and mechanism in I/R injured diabetic mice. Consequently, Ibrutinib improved the decreased cell viability and attenuated oxidative stress in the high glucose incubated PC12 cells which subjected to H/R injury. In the I/R injured diabetic mice, ibrutinib reduced the cerebral infarct volume, improved neurological deficits, ameliorated pathological changes, and improved autophagy in a slightly dose-dependent manner. Furthermore, the expression of PI3K/AKT/mTOR pathway-related proteins were significantly upregulated by ibrutinib treatment. In summary, our finding collectively demonstrated that Ibrutinib could effectively ameliorate cerebral ischemia/reperfusion injury via ameliorating inflammatory response, oxidative stress, and improving autophagy through PI3K/Akt/mTOR signaling pathway in diabetic mice.

Improved Early Recognition of Coronavirus Disease-2019 (COVID-19): Single-Center Data from a Shanghai Screening Hospital.

BACKGROUND: In December 2019, an outbreak of a novel coronavirus disease (COVID-19; previously known as 2019-nCoV) was reported in Wuhan, Hubei province, China, which has subsequently affected more than 200 countries worldwide including Europe, North America, Oceania, Africa and other places. The number of infected people is rapidly increasing, while the diagnostic method of COVID-19 is only by nucleic acid testing. OBJECTIVE: To explain the epidemiological characteristics, clinical features, imaging manifestations and to judge diagnostic value of COVID-19 by analyzing the clinical data of COVID-19 suspected and confirmed patients in a non-outbreak, Shanghai, China. To clarify the early epidemiology and clinical characteristics about COVID-19. METHODS: Cross-sectional, single-center case reports of the 86 patients screened at Zhoupu Hospital in Pudong New District, Shanghai, China, from January 23 to February 16, 2020. Epidemiology, demography, clinical, laboratory and chest CTs were collected and analyzed. The screened patients were divided into COVID-19 and non-COVID-19 based on nucleic acid test results. RESULTS: Of the 86 screened patients, 11 were confirmed (12.8%) by nucleic acid testing (mean age 40.73 ± 11.32, 5 males). No significant differences were found in clinical symptoms including fever, cough, dyspnea, sore throat, and fatigue (P > 0.05). No statistical difference was observed in plasma C-reactive protein (CRP) between the two groups (COVID-19 and non-COVID-19 ) of patients (P = 0.402), while the white blood cell count and lymphocyte count of the confirmed patients were slightly lower than those of the suspected patients (P < 0.05). Some non-COVID-19 chest CTs also showed subpleural lesions, such as ground-glass opacities (GGO) combined with bronchiectasis; or halo nodules distributed under the pleura with focal GGO; consolidation of subpleural distribution or combined with air bronchi sign and vascular bundle sign, etc. CONCLUSION: The early clinical manifestations and imaging findings of COVID-19 are not characteristic in non-outbreak areas. Etiological testing should be performed as early as possible for clinically suspected patients.

Autophagy and inflammation in ischemic stroke.

Appropriate autophagy has protective effects on ischemic nerve tissue, while excessive autophagy may cause cell death. The inflammatory response plays an important role in the survival of nerve cells and the recovery of neural tissue after ischemia. Many studies have found an interaction between autophagy and inflammation in the pathogenesis of ischemic stroke. This study outlines recent advances regarding the role of autophagy in the post-stroke inflammatory response as follows. (1) Autophagy inhibits inflammatory responses caused by ischemic stimulation through mTOR, the AMPK pathway, and inhibition of inflammasome activation. (2) Activation of inflammation triggers the formation of autophagosomes, and the upregulation of autophagy levels is marked by a significant increase in the autophagy-forming markers LC3-II and Beclin-1. Lipopolysaccharide stimulates microglia and inhibits ULK1 activity by direct phosphorylation of p38 MAPK, reducing the flux and autophagy level, thereby inducing inflammatory activity. (3) By blocking the activation of autophagy, the activation of inflammasomes can alleviate cerebral ischemic injury. Autophagy can also regulate the phenotypic alternation of microglia through the nuclear factor-κB pathway, which is beneficial to the recovery of neural tissue after ischemia. Studies have shown that some drugs such as resveratrol can exert neuroprotective effects by regulating the autophagy-inflammatory pathway. These studies suggest that the autophagy-inflammatory pathway may provide a new direction for the treatment of ischemic stroke.

Oxygen-glucose deprivation regulates BACE1 expression through induction of autophagy in Neuro-2a/APP695 cells.

Our previous findings have demonstrated that autophagy regulation can alleviate the decline of learning and memory by eliminating deposition of extracellular beta-amyloid peptide (Aß) in the brain after stroke, but the exact mechanism is unclear. It is presumed that the regulation of beta-site APP-cleaving enzyme 1 (BACE1), the rate-limiting enzyme in metabolism of Aß, would be a key site. Neuro-2a/amyloid precursor protein 695 (APP695) cell models of cerebral ischemia were established by oxygen-glucose deprivation to investigate the effects of Rapamycin (an autophagy inducer) or 3-methyladenine (an autophagy inhibitor) on the expression of BACE1. Either oxygen-glucose deprivation or Rapamycin down-regulated the expression of BACE1 while 3-methyladenine up-regulated BACE1 expression. These results confirm that oxygen-glucose deprivation down-regulates BACE1 expression in Neuro-2a/APP695 cells through the introduction of autophagy.

[Construction of eukaryotic expression vector containing hSNCA gene and its pathogenic mutants and its expression in PC12 cells].

AIM: To construct recombinant eukaryotic expression vectors pEGFP-C3-SNCA containing human wild-type (WT) and pathogenic mutations A30P, A53T alpha-synuclein (SNCA), and to obtain monoclonal PC12 cell lines overexpressing human wild-type and pathogenic mutations A30P, A53T alpha-synuclein by stable transfection. METHODS: Human wild type SNCA gene was cloned by using RT-PCR. By T-A extension cloning, the gene was ligated with T-vector and sequenced. Based on it, the recombinant eukaryotic expression vectors containing wild type SNCA synonymous mutation or its G88C (Ala30Pro) and G209A (Ala53Thr) pathogenic mutation were constructed by site-directed mutagensis using primer variance in mononucleotide. And different recombinant plasmids pEGFP-C3-SNCA were identified with PCR, restriction enzyme digestion and DNA sequencing. PC12 cells were transfected with different recombinant plasmids pEGFP-C3-SNCA by liposome transfection method, screened with G418, and subcloned by limited dilution method to obtain different monoclonal PC12 cell lines stably over-expressing human wild-type, A30P or A53T alpha-synuclein, respectively, and PC12 cells stably transfected with pEGFP-C3 were used as control group. These monoclonal PC12 cell lines were identified with RT-PCR, Western blot and fluorescence microscopy. RESULTS: According to result of PCR, the double digestion and gene sequencing, it was comfirmed that recombinant eukaryotic expression vectors containing wild type SNCA synonymous mutation or its Ala30Pro and Ala53Thr pathogenic mutation had been constructed successfully. By means of RT-PCR, Western blot and fluorescence microscope, it was comfirmed that objective gene sequences in PC12 cells were stably over-expressed. CONCLUSION: The recombinant pEGFP-C3-SNCA vectors containing wild type SNCA synonymous mutation or its Ala30Pro and Ala53Thr pathogenic mutations had been constructed successfully. The transfected monoclonal PC12 cells are obtained in which three SNCA gene isoforms had stable expression.