Objective To study the concentration of neurotrophins( including NGF, BDNF, NT3 and NT4) in the lung of SD rats infected by respiratory syncytial virus( RSV) , and to explore the relationship between the concentration of the neurotrophins, airway hyperresponsiveness and airway neural plasticity.Methods Twenty SD newborn rats were randomly divided into a control group and a RSV-infected group with ten rats in each group. The RSV-infected group were infected with 5 ×104 TCID50/0. 1 mL RSV each week. After 8 weeks, the bronchial responsiveness of the SD rats was assessed. The bronchial inflammation was assessed by HE staining with left lung. Synaptophysin and neurofilament expressions in the lung of SD rats were assayed by the immunohistochemistry staining. In situ hybridization was used to detect the RSV RNA in the lung. The concentration of neurotrophins in the lung of SD rats were detected by ELISA. Results The RSV-infected group showed elevated airway hyperresponsiveness and more inflammatory cells infiltrated in the lung; In situ hybridization showed positive signal of RSV RNA in lung interstitium of the RSV-infected rats. Synaptophysin and neurofilame levels in the airway were increased in the RSV-infected group. Supernatant levels of NGF and BDNF were significantly increased compared with the control group ( P lt;0. 05) . The NT3 and NT4 levels had no significant difference in all groups. The expressions of NGF and BDNF were positively related to the expressions of synaptophysin( r1 = 0. 892, r2 = 0. 995, P lt; 0. 05) and neurofilament( r1 = 0. 949, r2 =0. 936, P lt;0. 05) , also positively related to the airway hyperresponsiveness ( r1 =0. 929, r2 = 0. 910, P lt; 0. 05) . Conclusion RSV infection results in increased expressions of NGF and BDNF in the lung, which are correlated to the change of airway neural plasticity and airway hyperresponsiveness.
Objective To extract and purify the cytoplasmic neurotrophic proteins from bone marrow stromal cell and to test their neurotrophic activity. Methods Bone marrow stromal cells were collected from rat femur,after ultrasonicgrind and ultracentrifugation, the supernate was ultrafiltrated and concentrated,the proteins that molecular weight was greater than 10 ku were collected. The neurotrophic active substance was extracted and purified by Sephadex G-100 gel chromatography and high performance liquid chromatography (HPLC). Then their neurotrophic activity was tested in cultured spinal cord motoneuron with MTT method and morphous observation. Results After supernate was analyzed by Sephadex G-100 chromatography, peak Ⅱ could promote the growth of neuron. A further analysisof Peak II with HPLC showed that peak A could promote the growth of neuron. The SDS-PAGE analysis of peak A indicated that a main protein zone with molecular weight of 13 ku was obtained. Conclusion The protein of 13 ku in MSCs has neurotrophic activity.
Objective To study the effects of several neurotrophic factors and growth factors on the survival of human retinal ganglion cells(RGC)in vitro. Methods RGC were isolated from donor eyes and cultured.RGC in cell culture were identified by morphologic criteria and immunocytochemical staining.Various neurotrophic factors and growth factors were added individually to the cultures.Numbers of RGC in wells in which these agents had been added were compared with those from control wells(cultures without supplements). Results No or very few RGC were present in cell cultures containing medium without supplements or those supplemented with neurotrophin-3(NT-3),nerve growth factor (NGF),epidermal growth factor(EGF)amd plateletderived growth factor(PDGF).Numbers of RGC(per 10 fields)in cell cultures containing brain derived neurotrophic factor(BDNF),ciliary neurotrophic factor(CNTF),neurotrophin-4/5(NT-4/5)and basic fibroblast growth factor(bFGF)wer 4.08,1.23,2.63 and 2.65,respectively,significantly more than found in the control cultures. Conclusions BDNF,NT-4/5,bFGF,CNTF improve survival of human RGC in vitro,while NGF,NT-3,EGF and PDGF do not. (Chin J Ocul Fundus Dis, 1999, 15: 149-152)