BACKGROUND:Activation of Notch signaling plays a critical role in stem cel differentiation, and this effect seems to be cel-type dependent. Little is reported on the role of activation of Notch1 signaling in the differentiation of c-Kit+ bone marrow mesenchymal stem cels. OBJECTIVE:To analyze the influence of activation of Notch1 signaling on the differentiation of c-Kit+ bone marrow mesenchymal stem cels. METHODS:The Notch1 intracelular domain (N1-ICD) was obtained from the cDNA library by PCR and cloned intoBamHI/AgeI digested adenoviral GV314 plasmid to construct N1-ICD overexpressing shuttle plasmid, and the positive clones were verified by sequencing. N1-ICD shuttle plasmid and helper plasmids pBHGloxΔE1,3 Cre were used to co-transfect HEK293T cels to obtain N1-ICD overexpressing adenoviral particles (N1-ICD-Ad). The c-Kit+ subpopulation were isolated from bone marrow mesenchymal stem cels of the Sprague-Dawley rat femurviamagnetic activated cel sorting. After transfection of the c-Kit+ BMSCs with N1-ICD-Ad adenovirus, we assessed the activation of Notch1 signaling and differentiation in c-Kit+ bone marrow mesenchymal stem cels by quantitative RT-PCR and immunofluorescent staining. RESULTS AND CONCLUSION:N1-ICD coding sequence was successfuly generated from the cDNA library, and then was cloned into the linearized adenoviral vectors GV314. The resistant clones were verified by sequencing. With the assistance of packaging plasmids, recombinant N1-ICD-Ad adenovirus plasmids were successful packaged in HEK293T cels, and its title was 2×1012 PFU/L. c-Kit+ bone marrow mesenchymal stem cels with the purity of 91.6% were successfuly isolated from the bone marrow mesenchymal stem cels of the Sprague-Dawley rat femur. Compared with the blank and negative controls, N1-ICD-Ad infection in the c-Kit+ bone marrow mesenchymal stem cels led to substantial accumulation of N1-ICD in the cytoplasm and nuclei, significantly unregulated expressions of Hes1 (a downstream gene of Notch) and cardiomyocyte differentiation genes Nkx2.5 and cTnT, significantly increased the expression of von Wilebrand factor, an endothelial cel differentiation gene, and mildly increased the expression of smooth muscle22α, a smooth muscle cel differentiation gene. These experimental results indicate that the activation of Notch1 signaling contributes to multi-lineages differentiation of c-Kit+ bone marrow mesenchymal stem cels, and the construction of N1-ICD overexpressing adenoviral vector makes the foundation for further research on the role of Notch1 signaling in stem cel biology.

Objective To study the role and mechanism of orexin A in cell viability of Alzheimer's disease (AD) cell model PC12. Methods PC12 cells were treated with 0, 10, 20, 30, 40 and 50 μmol/L Aβ25-35 for 24 h, and then, cell viability was measured by MTT to confirm which concentration was the suitable one to establish the AD cell models. (1) AD cell models were treated with 0, 0.01, 0.1, 1 and 2μmol/L orexin A for 24 h, and then, 30μmol/L Aβ25-35 was added for 24 h; MTT assay was used to determine the cell viability to conform the suitable concentration of orexin A. (2) Inverted phase contrast microscope was employed to observe the morphology changes of PC12 cells from the control group, 30 μmol/L Aβ25-35 treatment group, and 0.01 μmol/L orexin A+30 μmol/L Aβ25-35 treatment group. (3) The PC12 cells were given pretreatment of orexin A receptor inhibitor SB408124 for 2 h, and cell viability was detected. Results (1) Aβ25-35 at concentration 30μmol/L was the suitable one to establish the AD cell models;after being pretreated with different concentrations of orexin A, the cell viability showed significant differences (F=27.120, P=0.000), and 0.01μmol/L orexin A was the suitable concentration. (2) Some of the cells from the 30μmol/L Aβ25-35 treatment group had breaking-off of protuberance and damaged soma;cells from 0.01μmol/L orexin A+30μmol/L Aβ25-35 treatment group had breaking-off of protuberance, and the degree of damaged soma was eased as compared with that in the 30μmol/L Aβ25-35 treatment group. (3) If the cell viability of the control group was 100％, cell viability of orexin A receptor inhibitor group was 109.10％±0.36％, which was significantly decreased as compared with that in the 0.01 μmol/L orexin A pretreated group (117.24％±2.72％, P<0.05). Conclusion Orexin A can improve the cell viability via combination of its specific receptor; orexin A and its specific receptor may be new targets for prevention and cure of AD.

Objective:To study the influence of G protein-coupled estrogen receptor 1 (GPER1) specific agonist G1 and antagonist G2 in epilepsy susceptibility of temporal lobe epileptic rats.Methods:Sixty rats were randomly divided into control group, G1 treatment group and G15 treatment group ( n=20). Rats in the latter two groups were intraperitoneally injected with GPER1 agonist G1 (10 μg) or antagonist G15 (40 μg) for a consecutive 12 d. Lithium chloride pilocarpine epilepsy models were prepared in the 3 groups. The behavior manifestations of these rats were observed within 1 h of intraperitoneal injection of pilocarpine; Racine grading was used to evaluate the severity of epileptic seizures every 5 min; the latency of epileptic seizures (Racine grading IV) and epileptic seizure grading at different time points in the 3 groups were compared. The EEG monitoring was performed to these rats, and EEG data were recorded from 10 min before pilocarpine injection to 2 h after pilocarpine injection; EEG time-frequency was analyzed by Fast-Fourier transform (FFT); distribution of brain electrical energy and changes of θ and α wave energy during 20 min of epileptic status were compared among the 3 groups. Results:(1) As compared with that in the control group and G1 treatment group, the latency of epileptic seizures in the G15 treatment group was significantly shortened ( P<0.05); 15 and 20 min after pilocarpine injection, the epileptic seizure grading of rats in G1 treatment group was statistically lower than that in control group ( P<0.05); 15-35 min after pilocarpine injection, the epileptic seizure grading of rats in G15 treatment group was significantly higher than that in control group ( P<0.05). (2) As compared with those in the control group, rats in the G1 treatment group had smaller brain wave amplitude, while the rats in the G15 treatment group had earlier seizure time, larger brain wave amplitude and higher frequency. There were no obvious changes in the amount of brain electrical energy between the G1 treatment group and control group; while the amount of brain electrical energy in the G15 treatment group 2 h after pilocarpine injection was higher than that in the control group. As compared with those in the control group and G1 treatment group, the θ and α wave energy values of rats in the G15 treatment group were significantly increased within 20 min of epileptic status ( P<0.05). Conclusion:Activation level of GPER1 might be associated with susceptibility to epileptic seizures, and specific inhibition of GPER1 activation can enhance the susceptibility to epilepsy and increase the energy values of specific frequency bands during epilepsy.

There is a high risk of myelosuppression in pelvic malignant tumors during concurrent chemoradiotherapy. The dose-volume relationship of pelvic exposed bone marrow( bone) is related to acute hematological toxicity during radiotherapy and chemotherapy,but lacks recognized parameters in this respect. The hematopoietic capacity of the bone marrow(bone)in different parts of the pelvic cavity is heterogeneous,and the pelvic bone marrow near the central axis has the strongest hematopoietic capacity,namely functional bone marrow. The relationship between dose-volume parameters of pelvic functional bone marrow and acute hematologic toxicity during chemoradiotherapy of pelvic malignant tumors may be the future direction.

Objective : To investigate the effect of ginsenoside Rg1 (GRg1) on human retinal microvascular endothelial cells (HRMECs) glycolysis by regulating pyruvate kinase M2 ( PKM2) expression. Methods : HRMECs were cultured in vitro and divided into normal control (NC) group, high glucose (HG) group, high glucose + ginsenoside Rg1 (HG + GRg1) group, high glucose + ginsenoside Rg1 + low expression PKM2 ( HG + GRg1 + si-PKM2) group, and high glucose + ginsenoside Rg1 + overexpression PKM2 (HG + GRg1 + OE⁃PKM2) group. si-PKM2 and OE⁃PKM2 were transfected into HRMECs cells by cell transfection. The expression of PKM2 mRNA in HRMECs was detected by qRT⁃PCR. The expression levels of related proteins in HRMECs were detected by Western blot. The number of lumen formation in vitro was observed under an inverted microscope to quantify the angiogenesis ability. Cell culture medium of each group was collected, and glucose intake, lactate production and adenosine triphosphate(ATP)content were detected by glucose detection kit, lactate detection kit and ATP detection kit,re spectively. Results : HG induced HRMECs significantly increased the number of blood vessel formation, glycolysis and PKM2 expression, while GRg1 treatment significantly reduced the number of blood vessel formation, glycolysis and PKM2 expression; transfection of si⁃PKM2 assisted the inhibitory effect of GRg1 on glycolysis and angiogenesis while transfection of OE⁃PKM2 interfered with the function of GRg1 . Conclusion GRg1 inhibits angiogenesis by inhibiting PKM2 to reduce glycolysis of HRMECs.