ABSTRACT
ObjectiveBone marrow-derived mesenchymal stem cells (MSCs) can promote ovarian angiogenesis, improve ovarian insufficiency caused by chemotherapy, and repair ovarian function, while heat shock pretreatment can reduce the apoptosis rate of stem cells and improve the therapeutic effect of stem cells. This study aims to investigate the effect of heat shock pretreatment on MSCs, and further study the effect of heat shock pretreated mesenchymal stem cells on chemotherapy-induced apoptosis of ovarian granulosa cells.Methods1. The bone marrow-derived MSCs of rats were isolated, cultured and identified, and pretreated within a 42 °C water bath for one hour. 2. Cisplatin (5 mg/L) was added to MSCs to simulate the local microenvironment of chemotherapy. MSCs were divided into four groups: blank control group, heat shock control group, model group, and heat shock model group. The effects of heat shock pretreatment on the proliferation, apoptosis and survival rate of MSCs were investigated by CCK-8 method, Hoechst33342/PI, and flow cytometry. 3. We isolate and culture rat ovarian granulosa cells (GCs) to establish an in vitro model of GCs injury under the induction of cisplatin (5 mg/L). The experiment was carried out in four groups: a control group, model group, MSCs model group, HS-MSCs model group. The apoptosis and survival rate were detected by Hoechst33342/PI and flow cytometry, respectively.Results1. The proliferation level and survival rate of MSCs in the heat shock control group were significantly higher than those in the other three groups, and the apoptosis rate was significantly lower than the other three groups (P<0.05). Compared to the model group, the proliferation level of the heat shock model group was significantly increased, and the apoptosis rate was significantly decreased (P<0.05), and the cell survival rate increased; 2. The apoptosis rate of GCs in the HS-MSCs model group was significantly lower than that in the other three groups. Compared to the MSCs model group, the apoptosis rate of GCs in the HS-MSCs model group was significantly decreased (P<0.05).ConclusionHeat shock pretreatment can increase the proliferation level and survival rate of MSCs, and reduce its apoptosis rate. Heat shock pretreated stem cells can effectively inhibit chemotherapy-induced apoptosis of ovarian granulosa cells.
ABSTRACT
Aim To explore the optimal way of breeding and genotype identification of Arrb2 knockout mice, and to find a simple and quick polymerase chain reaction ( PCR) method for the genotyping of Arrb2 knockout mice. Methods Breeding homozygote genotype of Arrb2 gene knockout mice were copula-ted with wild-type C57BL/6J mice, and then the heterozygous mating were used for mating. The growth and development of off-spring were observed. The genomic DNA was extracted from the tail of two-week-old mice. PCR was employed to amplify the Arrb2 gene fragment, and electrophoresis was used to present the gene type. Results The breeding and reproducing were successful and three genotype offspring, including wild-type,heterozygous and homozygous knockout mice were obtained. Agarose gel electrophoresis results showed the size of PCR prod-ucts was about 186 bp and 224 bp, which was consistent with the expected target gene fragment, and identified Arrb2 gene knockout mice of different genotypes successfully. Western blot analysis demonstrated the lack ofβ-arrestin2 protein in the major organs from Arrb2 -/ - mice compared with Arrb2 +/ + and Arrb2 +/ - mice. Conclusions It is feasible to obtain the homo-zygous Arrb2 knockout mice by inbreeding heterozygotes. It is simple, rapid and reliable to identify mouse genetype by PCR.
ABSTRACT
Objective To explore the therapeutic potential of miR-21 in rat model of chemotherapy-induced premature ovarian failure (POF).Methods Lentivirus-mediated miR-21 (LV-miR-21) was constructed successfully in vitro with molecular biology methods.Rats were divided into 4 groups named control group,model group,blank vector group and miR-21 group.Rat models of chem0therapy-induced POF were established in the latter 3 groups by intraperitoneal injection ofcytoxan (CTX).Bilateral ovaries of rats in miR-21 group were injected with LV-miR-21,of rats in blank vector group were injected with lentivirus vector,and rats in model group received no treatment.At 1,15,30,45 and 60 days after the last injection,blood sample was collected,the rats were then sacrificed and the ovaries were removed.The estrous cycle was observed by vaginal smears.The E2 level was detected by chemiluminescent immunoassay,and the follicle stimulating hormone (FSH) level was detected by homologous double antibody radiation immunoassay.Ovary weights were measured,and the follicle count was conducted through observing paraffin section under microscope.The apoptosis of ovarian granulosa cells was analyzed by TUNEL assay.Results During 15-30 days,30-45 days and 45-60 days after the last injection,regular estrous cycle was recovered respectively in 8,5 and 3 rats in miR-21 group.At the 15th,30th,45th and 60th day after the last injection,the E2 level was higher in miR-21 group than in model group and blank vector group,but the FSH level showed the opposite trend (P=0.000).At the 45th and 60th day after the last injection,the follicle numbers at all stages increased markedly in miR-21 group than in model group and blank vector group (P=0.000).At the 30th,45th and 60th day after the last injection,the ovary weights were higher in miR-21 group than in model group and blank vector group.At the 15th,30th,45th and 60th day after the last injection,the apoptosis rate of ovarian granulosa cell were significantly lower in miR-21 group than in model group and blank vector group (P=0.000).Conclusion Up-regulation of miR-21 expression may partly recover the ovarian structure and function damaged by CTX.