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AIM: To investigate the possibility that hepatocyte growth factor (HGF) directly induces differentiation of human embryonic stem cells (hESCs) into neural progenitors (NPs). METHODS: hESCs colonies were induced to form the embryoid body (EB). Four-day-old EBs were randomly divided into 4 groups: control group (EBs were cultured in neural induction medium);G5 supplement group (EBs were cultured in neural induction medium supplied with G5 supplement);HGF group (EBs were cultured in neural induction medium supplied with 10 mg/L HGF), and HGF+G5 group (EBs were cultured in neural induction medium supplied with 10 mg/L HGF and G5 supplement). After induced in suspension system for 7 days, EBs with various treatments were cultured in poly-D-lysine/laminin-coated plates for 7-10 days for selection of NPs. NPs were gathered by 0.3 g/L dispase treatment and characterized by immunofluorescence staining. The percentages of the nestin+ cells in NPs in various groups were detected by fluorescent activated cell sorter (FACS). The multipotency of NPs was determined by immunofluorescence staining after the NPs were cultured without G5 and HGF for 7 days. The expression of region markers of neural progenitors treated with sonic hedgehog (Shh) protein (one of the neural inductive signals), was detected by RT-PCR. RESULTS: HGF+G5 supplement induced hESCs differentiation into neural progenitors. Immunofluorescence staining indicated that NPs differentiated from hESCs expressed NP markers including nestin, Pax6 and musashi-1. FACS data showed that the proportion of nestin positive cells in HGF+G5 supplement group (87.3%±3.9%) was the highest in all treatment groups. The time of HGF and G5 supplement treatment was important to differentiate into NPs, the maximal effect was observed at 7th day. After treated with Shh, the expression of ventral forebrain/hindbrain marker genes (Nkk2.1, and Nkk2.2) and hindbrain progenitor marker gene Gbx2 in NPs were upregulated, while the forebrain progenitor marker genes Otx2 and Bf1 were downregulated. CONCLUSION: The neural induction system containing HGF and G5 supplement effectively induces the differentiation of hESCs into NPs, which might be a potent model for investigating the mechanism of neural development and differentiation.
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Objective To investigate the protective effect of hepatocyte growth factor (HGF) on cultured Sprague-Dawley rat cortical neurons injured through hypoxia/reoxygenation.Methods Primary cultured cerebral cortical neurons were isolated from newborn rots.Neurons were pre-incubated with different concentrations (15,30 and 60 μg/L) of HGF.The cell viability was detected by MTT.Apoptosis was measured by Hoechst 33258 staining and flow cytometer.Lactate dehydrogenase (LDH) and caspase-3 activity were determined by colorimetry.Results Compared with normal group,hypoxia/reoxygenation treatment significantly decreased cell viability,increased LDH activity and the percentage of apoptotic cells.Pretreatment of HGF for 12 h could remarkably reverse the decrease of cell viability and the increase of apoptosis rate in neurons induced by hypoxia/reoxygenation treatment.HGF pre-treatment also attenuated the activity of LDH and caspase-3 in a dose-dependent manner.The effects of HGF could be inhibited by a special PI3K/Akt pathway inhibitor,LY294002.Condusion HGF could attenuate rat cortical neuron injury induced by hypoxia/reoxygenation.The neuroprotective effect of HGF may be related to activating PI3K/Akt pathway,and further suppressing the expression of caspase-3.
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0.05).Conclusion The administration of helicid to pregnant rats did not affect the early development of nervous system, neurobehavioral function and brain histology of offspring.
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In recent years, various studies and analyses related to cosmetics safety were conducted according to routine tests in Hygienic Standard of Cosmetics (2007), and the eligible rates of tested cosmetics were high. But the other prohibited and limited use components, such as antibiotics were analyzed rarely, and meanwhile some kinds of cosmetic related dermatitis cases appeared dramatically. Several dermatitis, especially contact dermatitis and hormone dependent dermatitis symptoms were not contained in Diagnostic Criteria and Principles of Management of Skin Diseases Induced by Cosmetics-General Guideline, GB 17149.1—1997. So it indicated the standard, GB 17149.1—1997 should be revised and some prohibited and limited use components such as hormone and antibiotic testing should be appended to the safety analysis of cosmetics.
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0.05).Conclusion:Helicid had no effects on the early development of central nervous system in rat offspring.