ABSTRACT
Objective To explore the role of mechanical properties of embryonic neuroepithelial cells in the process of neural tube closure.Methods Neural tube defects (NTDs) mouse model was established by intragastric administration with all-trans retinoic acid at embryo 7.25 day.All the pregnant mice were sacrificed at embryo 9.5 day and 11.5 day,respectively,and the primary neuroepithelial cells were isolated from neural tube tissue of normal and NTDs mice,respectively.The mechanical characteristics of neuroepithelial cells were analyzed using micropipette aspiration technique combined with a standard solid viscoelastic mechanical model.Results The mechanical characteristics of mouse embryonic neuroepithelial cells showed typical viscoelastic solid characteristics.Compared with the control group,the three viscoelastic parameters,i.e.equilibrium modulus,transient modulus and apparent viscosity coefficient,of the neuroepithelial cells in the NTDs group were significantly increased,and the differences were statistically significant (all P＜0.05).However,there was no significant difference in the viscoelastic parameters of the same group between embryo 9.5 d and 11.5 d (all P＞0.05).Conclusion The decrease in the deformability of embryonic neuroepithelial cells may be one of the factors responsible for neural tube closure disorders.
ABSTRACT
Objective To study the growth difference and possible mechanism between nasopharyngeal carcinoma (NPC) cell line CNE-2 and its subclone S-18.Methods CNE-2 and S-18 cells were cultured in vitro.6 x 105 cells/mouse were xenografted subcutaneously in the back of nude mice.The volumes of rumors were measured on the 3 rd,7 th,10 th,14 th day after grafting.Mice were sacrificed on the 14 th day and tumors were isolated and weighed.RNA from tumor tissues were extracted and transcriptional levels of HSP27 and NF-K B were detected.Results (1) S-18,instead of CNE-2,grew to form tumor mass 7 days after xenografting subcutaneously;both cell lines formed tumor mass 10 days after xenografting,however,the volumes of S-18 tumors [(223.13 ± 21.32) mm3,10 th day;(420.25 ± 24.52) mm3,14 th day] were significant bigger than CNE-2tumors [(113.70±11.70) mm3,10thday;(279.86±25.78) mm3,14thday];The weights of S-18 umors were significantly higher than CNE-2 tumors on the 14 th day after xenografting;(2) The transcriptional levels of HSP27 and NF-KB in S-18 tumor were significantly higher than in CNE-2 tumor.Conclusion Xenografted S-18 NPC grows faster than Xenografted CNE-2 NPC.HSP27 and NF-κ B are probably involved in the regulation of growth in NPC.
ABSTRACT
ObjectiveTo examine the protective effects of 17-β estradiol on the experimental model of spinal cord injury (SCI) rats. Methods One hundred and eighty male Sprague Dawley (SD) rats, after Allen' s model, SD rats were divided into three groups: the sham group, the acute spinal cord injury (control groups) and the acute spinal cord injury supplying with 17-β estradiol treatment group. SCI was made by Allen's weight dropping, impacting on the posteriors of spinal cord T10. The content of malonyldialdehyed (MDA), glutathione (GSH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined by chromatometry. The expressions of Caspase-3 and Bcl-2 family in the injured spinal cord were detected by immunohistochemical staining. Results The BBB scores at each time point in 17-β estradiol treatment group were significantly higher than that in SCI group (P<0.05). The contents of GSH, SOD, GSH-Px and the expression of Bcl-2 protein at the majority of time point in 17-β estradiol treatment group were significantly higher than that in SCI group(P<0.05), however, the MDA, Caspase-3 and Bax were markedly decreased (P<0.05). Conclusions This study suggests that 17-β estradiol administration might prevent the cells from SCI-induced apoptosis by triggering to reduce the oxidative stress.