Hypoxia inducible factor-1αis a kind of hypoxia response factor. Acute cerebral ischemia and anoxia can induce up-regula-tion of hypoxia inducible factor-1α, and the downstream genes, which plays a role in both the energy metabolism and collateral circulation after cerebral ischemia. Neural stem and progenitor cells regeneration also benefit the functional outcome after ischemic stroke. Hypoxia in-ducible factor-1αmay induce proliferation and differentiation of neural stem and progenitor cells through Notch, Wnt/β-catenin pathways, etc., in the ischemic stroke model.

BACKGROUND:Human amniotic membrane-derived mesenchymal stem cells (AMSCs) are considered to be one kind of adult stem cells that can be easily obtained in large quantities without using an invasive method. Because of their low immunogenicity, anti-inflammatory properties, multipotency of differentiation and without ethical issue, human amniotic membrane-derived mesenchymal stem cells have been proposed as a good candidate to be used in celltherapy and regenerative medicine. However, the biological properties and the differentiation capacity of human amniotic membrane-derived mesenchymal stem cells are stil poorly characterized. OBJECTIVE:To establish a practical method for isolation and purification of human amniotic membrane-derived mesenchymal stem cells, and to study the biological characteristics and dopaminergic neural-like celldifferentiation potential of the human amniotic membrane-derived mesenchymal stem cells. METHODS:Human amniotic membrane-derived mesenchymal stem cells were disassociated and isolated from the amniotic membrane by trypsin and col agenase based enzymic digestion, and purified by percol mediated density gradient centrifugation. Expressions of surface antigens and transcription factors of the human amniotic membrane-derived mesenchymal stem cells were determined by flow cytometry and western blot assays. Based on the osteogenic and adipogenic induction, the multipotent differentiation capability of human amniotic membrane-derived mesenchymal stem cells was determined. Induction of neural celldifferentiation of human amniotic membrane-derived mesenchymal stem cells was conducted in Neurabasal conditioning medium with ATRA supplement. Neural cellassociated bio-markers were determined by immunofluoresence staining and confocal microscope. RESULTS AND CONCLUSION:In this study, we performed a practical method to isolate and purify human amniotic membrane-derived mesenchymal stem cells and amniotic epithelial cells simultaneously, with high cells yield. We demonstrated a group of constitutive expressions of neural antigens and embryonic associated transcription factor proteins (OCT-4, SOX-2 and KLF4) in fresh isolated human amniotic membrane-derived mesenchymal stem cells as wel as in human amniotic membrane-derived mesenchymal stem cells after in vitro passage, which suggested that the human amniotic membrane-derived mesenchymal stem cells not only possessed intrinsic tendency to neural celldifferentiation, but also maintained their stem cellcharacteristics after in vitro passage. We stimulated the human amniotic membrane-derived mesenchymal stem cells in the neurobasal-A and B27 based conditioning medium to induce neural celldifferentiation. The induced human amniotic membrane-derived mesenchymal stem cells displayed an up-regulation of expression in panel of neural and dopaminergic associate molecules (β-tubulin III, neuron-specific nuclear protein, tyrosine hydroxylase, glial fibril ary acidic protein, myelin basic protein and nestin) by flow cytometry and immunofluorescence staining, which demonstrated the multipotent differentiation capability and dopaminergic neuron-like differentiation potential of the human amniotic membrane-derived mesenchymal stem cells.

Objective To investigate the effect ofmiR-27a-3p on proliferation,apoptosis and cell cycle of hepatoma cells.Methods A quantitative real-time polymerase chain reaction (qPCR) was used to detect differential expression of miR-27a-3p in normal hepatic epithelial cells (L02) and hepatoma cells (HepG2 and PLC).Cell experiment was divided into four groups:HepG2 overexpression cells,Mi-27a-3p overexpression group (Mi-27a) and negative control group (Mi-Con);PLC knockdown cells,Mi-27a-3p knockdown group (Miinhibitor-27a) and negative control group (Mi-inhibitor-Con).The expression of microRNA-27a-3p in each group after transfection was detected by qPCR analysis.MTT assay was used to detect the cell proliferation.Flow cytometry was used to detect the apoptosis and cell cycle.One-way ANOVA was used for multiple comparisons,and t-test was used to compare two groups.Results qPCR results showed that the expression levels of miR27a-3p in L02,HepG2 and PLC increased sequentially,and the relative expression levels were 1.07 ± 0.04,4.81 ± 0.64 and 11.31 ± 0.92,respectively (P ＜ 0.05).MTT assay showed that the cell viability of HepG2 cells transfected with miR-27a-3p overexpression plasrnid was significantly deereased compared with the negative control group (P ＜ 0.05).The apoptosis assay showed that the apoptosis rate of miR-27a-3p overexpression group was higher than the negative control group (P ＜ 0.05).The cell cycle results showed that the proportion of S phase cells in the miR-27a-3p overexpression cell group was significantly lower than the negative control group (P ＜ 0.05).Furthermore,microRNA-27a-3p knockdown validation in PLC cells showed that MTT,apoptosis and cell cycle tests results were opposite to the results of HepG2 overexpression cells,and the differences were statistically significant (P ＜ 0.05).Conclusion miR-27a-3p can significantly inhibit the proliferation of hepatoma cells,promote cell apoptosis,alter the cell cycle distribution,and may become a potential target in hepatocellular carcinoma therapy.

Objective To evaluate cerebral perfusion through brain computed tomography perfusion imaging (CTP) in order to investigate the relationship between cerebral perfusion and vascular cognitive impairment (VCI).Methods A total of 103 patients with ischemic stroke were recruited, who received thrombolytic therapy and CTP test in the Fourth Affiliated Hospital of China Medical University from December, 2016 to May, 2017. The patients were divided into normal cognitive function group (control group, n=43), vascular cognitive impairment-no dementia group (VCIND group, n=48), and vascular dementia group (VD group, n=12) according to the degree of impairment in cognitive function after the assessment of Mini-Mental State Examination (MMSE) and Clock Drawing Test (CDT). The characteristics of cerebral blood flow perfusion in region of interest of brain CTP were analyzed.Results There was difference in incidence of diabetes among three groups (χ2=7.556, P<0.05). The rate of diabetes was higher in VCIND group and VD group than in the control group. Age and diabetes were the independent risk factors for VCI (OR>1, P<0.05). There was difference in cerebral blood volume (CBV) in frontal lobe, temporal lobe, and parietal lobe among three groups (F>3.216, P<0.05). CBV in frontal lobe, temporal lobe, and parietal lobe reduced in VD group than in the control group (P<0.05), while CBV in frontal lobe and temporal lobe reduced in VD group than in VCIND group (P<0.05). There was difference in mean transit time (MTT) in left temporal lobe, left parietal lobe, and centrum semiovale among three groups, while there was difference in left occipital lobe in time to peak (TTP) among three groups (F>3.116, P<0.05). MTT and TTP were higher in VD group than in the control group and VCIND group (P<0.05). There was no difference in cerebral blood flow (CBF) in both left and right brain, and MTT and TTP in right brain among three groups (P>0.05). CBV in frontal lobe, parietal lobe and right temporal lobe demonstrated positive relationship with the scores of MMSE (r>0.203, P<0.05). CBV in parietal lobe and left frontal lobe also demonstrated positive relationship with the scores of CDT (r>0.214, P<0.05).Conclusion The cerebral blood flow perfusion reduced in different levels of VCI, especially in frontal lobe, temporal lobe and parietal lobe. Cerebral blood flow perfusion reduced with the progress of cognitive impairment, and the left hemisphere injured earlier than the right one. Brain CTP may be applied in the early recognition of VCI.

Human enterovirus 71 (EV71) is the main causative pathogen of hand, foot, and mouth disease (HFMD) in children. The epidemic of HFMD has been a public health problem in Asia-Pacific region for decades, and no vaccine and effective antiviral medicine are available. Curcumin has been used as a traditional medicine for centuries to treat a diversity of disorders including viral infections. In this study, we demonstrated that curcumin showed potent antiviral effect again EV71. In Vero cells infected with EV71, the addition of curcumin significantly suppressed the synthesis of viral RNA, the expression of viral protein, and the overall production of viral progeny. Similar with the previous reports, curcumin reduced the production of ROS induced by viral infection. However, the antioxidant property of curcumin did not contribute to its antiviral activity, since N-acetyl-l-cysteine, the potent antioxidant failed to suppress viral replication. This study also showed that extracellular signal-regulated kinase (ERK) was activated by either viral infection or curcumin treatment, but the activated ERK did not interfere with the antiviral effect of curcumin, indicating ERK is not involved in the antiviral mechanism of curcumin. Unlike the previous reports that curcumin inhibited protein degradation through ubiquitin-proteasome system (UPS), we found that curcumin had no impact on UPS in control cells. However, curcumin did reduce the activity of proteasomes which was increased by viral infection. In addition, the accumulation of the short-lived proteins, p53 and p21, was increased by the treatment of curcumin in EV71-infected cells. We further probed the antiviral mechanism of curcumin by examining the expression of GBF1 and PI4KB, both of which are required for the formation of viral replication complex. We found that curcumin significantly reduced the level of both proteins. Moreover, the decreased expression of either GBF1 or PI4KB by the application of siRNAs was sufficient to suppress viral replication. We also demonstrated that curcumin showed anti-apoptotic activity at the early stage of viral infection. The results of this study provide solid evidence that curcumin has potent anti-EV71 activity. Whether or not the down-regulated GBF1 and PI4KB by curcumin contribute to its antiviral effect needs further studies.

Axonal degeneration is one of the key features of neurodegenerative disorders. In the canonical view, axonal degeneration destructs neural connections and promotes detrimental disease defects. Here, we assessed the enteric nervous system (ENS) of the mouse, non-human primate, and human by advanced 3D imaging. We observed the profound neurodegeneration of catecholaminergic axons in human colons with ulcerative colitis, and similarly, in mouse colons during acute dextran sulfate sodium-induced colitis. However, we unexpectedly revealed that blockage of such axonal degeneration by the Sarm1 deletion in mice exacerbated the colitis condition. In contrast, pharmacologic ablation or chemogenetic inhibition of catecholaminergic axons suppressed the colon inflammation. We further showed that the catecholaminergic neurotransmitter norepinephrine exerted a pro-inflammatory function by enhancing the expression of IL-17 cytokines. Together, this study demonstrated that Sarm1-mediated neurodegeneration within the ENS mitigated local inflammation of the colon, uncovering a previously-unrecognized beneficial role of axonal degeneration in this disease context.