ObjectiveTo observe the effect of conditional knocking out (KO) vascular endothelial growth factor (VEGF) gene on the mouse model of oxygen induced retinopathy (OIR).MethodsThe conditional VEGF KO mice were generated using Cre-Loxp technology, resulting in the deletion of VEGF in a portion of Müller cells permanently in mouse retina. Cre positive was CKO mice, Cre negative was NKO mice. OIR was induced by keeping mice in 75% oxygen at postnatal 7 days (P7) to P12 and in room air from P12 to P17 (each 20 mice for CKO and NKO, respectively). The mice mortality was analyzed. At day P17, the percentage of retinal avascular area was calculated using retinal flat-mounting with fluorescence angiography, the number of vascular endothelial cell nucleus breaking through retinal inner limiting membrane was counted with hematoxylin eosin (HE) staining of retinal sections, and the expression of hypoxia-inducible factor-1α (HIF-1α) was detected by immunofluorescence analysis. ResultsDuring the development of OIR, the mortality rate of CKO mice (65.00%) was higher than that of NKO mice (30.00%) with the significant difference (x2=4.912, P=0.027). At day P17, all the mice retinas were harvested. The retinal fluorescence angiography displayed that the normal retinal vascularization of CKO mice was delayed, and large avascular areas were observed. Meanwhile, rare new vascular plexus was found in CKO mice and the thickness of whole retina decreased dramatically. In contrast, NKO mice developed larger area of normal retinal vascular network structure with higher blood vessel density and more new vascular plexus with obvious fluorescein leakage. The percentage of avascular area in CKO mice [(28.31±11.15)%] was higher than NKO mice [(16.82±7.23)%] with the significant difference (t=2.734, P=0.014). The HE staining of retinal sections indicated smaller counts of vascular endothelial cell nucleus breaking through retinal inner limiting membrane in CKO mice (26.10±6.37) when compared to NKO mice (28.80±7.59) , the difference was significant (t=2.437, P=0.016). The immunofluorescence analysis showed stronger expression of HIF-1α in CKO mice than NKO mice, which was mainly located in the retinal ganglion cell layer.ConclusionsThe local VEGF gene knockout partially inhibits retinal neovascularization in OIR mice. However, it also suppresses the normal retinal blood vascular development with a decrease of OIR mice survival ability.
ObjectiveTo establish the co-culture model of mice's early embryo and tumor cells in Vitro to observe the embryonic development and biologic behavior of tumor cells in the same microenvironment and discuss their interaction.
MethodsWe acquired 2-cell embryos from mice, and then co-cultured them with tumor cell lines of mice in Vitro. We observed the development of embryos in Vitro and the rates of 4-cell embryos, morula and blastocyst formation. The transwell chamber was used for culture. Methylthiazolyldiphenyl-tetrazolium method was used to test the proliferative activity of tumor cells, while the flow cytometry was used to test its apoptosis. The interaction of co-cultured embryos and tumor cells was analyzed by propidium iodide staining and immunohistochemical technique.
ResultsThe co-cultured 2-cell embryos could continue surviving and developing. The rates of 4-cell embryos, morula and blastocyst formation increased significantly in the co-cultured group (P<0.05). There was no significant difference in the proliferative activity and apoptosis of tumor cells between the co-cultured group and the control group (P>0.05). Tumor-free ring formed between the trophoblast and tumor cells. We could observe tumor cells stacked around the tumor-free ring. However, no difference in expression of proliferating cell nuclear antigen and B-cell lymphoma leukemia-2 was observed in tumor cells stacking around the tumor-free ring compared with those elsewhere.
ConclusionThe development of 2-cell embryos is enhanced in the co-culture model. The proliferative activity and apoptosis of tumor cells are not affected in this model. A tumor-free ring can form between trophoblast and tumor cells. However, the proliferative activity of tumor cells is not affected by this ring.
Objective
To study the progressive development of the retinas through an observation on the histological changes of the retinas from neonatal mice of different day-ages.
Methods
The retinas from the mice of 1 to 20 days of age were examined by light microscopy,and from 1 to 3 days,by autoradiography.
Results
The retinas of the mice below 3 days of age only had the RPE cells layer,the neuroblast layer and the ganglion cell layer.With the increase in dayage,the retinas developed gradually and would be mature in the 20th day.
Conclusions
The retinas of mice is a kind of immature tissue before the 20th days,so it can be considered as transplantation donors.
(Chin J Ocul Fundus Dis, 1999, 15: 174-176)
ObjectiveTo determine the signal pathway of specifically expressed oncostatin M(OSM) in lens inducing retinal degeneration in transgenic mice.MethodsA sequence-truncated OSM cDNA (661 bp) of mice was linked to αA-crytallin promoter, and was micro-injected into unicellular embryo to set up the model of transgenic mice. Reversal transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of gp130/OSMRβ receptor in the retinae of OSM transgenic and non-transgenic mice. Rabbit anti-phosphorylated STAT-3 antibody was used to detect the protein expression of phosphorylated STAT-3，and mouse anti-cytochrome C antibody was used to detect the distributing of cytochrome C in retinae. ResultsExpression of gp130/OSMRβmRNA was found in retina of non-transgenic mice. At the 17.5th day in the embryonic stage, significant accumulation of the phosphorylated STAT-3 was detected in the retinal nucleolus in OSM transgenic retina. At the first day after birth, intensive staining of cytochrome C in OSM transgenic retina was found. Conclusionsspecifically expressed OSM in lens may act on gp130/OSMRβ receptor in retinae, activate STAT-3, and cause the release of cytochrome C from mitochondria, which eventually induces widespread retinal degeneration.(Chin J Ocul Fundus Dis, 2005,21:167-169)
Objective To observe the effect of Minocycline on RP process of retinal pigmentary degeneration rd mice［C3H/HeN (Pde6brd-/rd-)］. Methods 40 rd mice were divided into ten groups randomly: 5 experimental groups and 5 control groups, 4 rd mice in each group. The experimental group received intraperitoneal injection of minocycline 22.5mg/kg while the control group received saline 10ml/kg every day from the postnatal day 1 (P1) . Mice were sacrificed at P1, P7, P14, P21 and P28 respectively. Eyeballs were enucleated to carry out histology observation and apoptosis cell detection. Meanwhile, to statistically analyze the number of retinal photoreceptor cells,the thickness of outer nuclear layer (ONL)and the number of apoptosis cells. Results （1）Photoreceptor cell began to apoptosis on P7, peaked on P14, and totally disappeared on P28. （2）No statistically significant differences were found of the number of photoreceptor cells and the thickness of ONL on P7 between the experimental group and the control group. (3) The number of photoreceptor cells and the thickness of ONL in the experimental were more than that in the control group at P14, P21, P28 respectively, the differences are statistically significant（Plt;0.05）. (4) The apoptotic cells on ONL were less in the experimental group than that in the control group on P7 and P14 respectively, the difference are statistically significant（Plt;0.05）. Conclusions Minocycline appears to protect photoreceptor cell from apoptosis in the early stage of the retinal degeneration mice, but it may not completely prevent RP from occurrence.
ObjectiveTo observe the anticancer efficacy of ginsenoside Rg3 on colorectal cancer in vitro and in vivo.
MethodsMice colorectal cell line (CT26) was incubated in 96-well plates (3×103-4×103 per well) with various concentrations of ginsenoside Rg3 (0, 5, 10, 15, 20 μg/mL) for 24 hours and 48 hours. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-dipheny 1-2-H-tetrazolium bromide assay was used to detect the inhibitory rate of cells. Xenograft models were established by subcutaneous implantation of CT26 cells into BABL/c mice. Each mouse was injected with 1×107 cells suspended in serum-free medium. Xenograft mice were randomized into four groups: physiological saline group, ginsenoside Rg3 5 mg/kg group, ginsenoside Rg3 10 mg/kg group, and ginsenoside Rg3 20 mg/kg group. Ginsenoside Rg3 was administrated to mice by intragastric gavage. All animals were observed for activity, body weight, tumor size, survival time, mental state and adverse effect of ginsenoside Rg3. Hematoxylin-eosin stain was used for comparing necrosis rate among groups.
ResultsThe inhibitory rates of cells were increasing following the elevating concentrations of ginsenoside Rg3. The anti-proliferation effect of ginsenoside Rg3 for 48 hours was weaker than the anti-proliferation effect for 24 hours. The decrease of mice body weight was slower than physiological saline group after administration of ginsenoside Rg3, and the number of mice with worse physiological state, lack of activity and loss of appetite in physiological saline group were more than that in ginsenoside Rg3 groups. However, these results among four groups were not significantly different (P>0.05). There were no obvious adverse effects of ginsenoside Rg3 found during the whole study. The necrosis rate of physiological saline group, Rg3 10 mg/kg group and Rg3 20 mg/kg group was 20%, 60% and 80% respectively.
ConclusionGinsenoside Rg3, as a single agent, still has anticancer activity. The anticancer efficacy is increasing following the elevating concentrations of ginsenoside Rg3. Ginsenoside Rg3 is a dose dependent agent.
ObjectiveTo study the possibility of the C17.2 neural stem cells (NSCs) differentiating into neural cells induced by serum-free condition medium of olfactory ensheathing cells (OECs) and to detect the cell viability of the differentiated cells.
MethodsOECs were isloated and cultured from the olfactory bulbs of 3-day-old postnatal mouse to prepare serum-free condition medium of OECs. After C17.2 NSCs were cultured with H-DMEM/F12 medium containing 15% FBS and the cell fusion reached 80%, the 3rd passage cells were induced by serum-free condition medium of OECs in the experimental group, by H-DMEM/F12 in the control group, and non-induced C17.2 NSCs served as the blank control group. The growth condition of cells was observed with inverted microscope. After 5 days, the immunofluorescence staining[microtubule-associated protein 2 (MAP-2) and β-tubulin-Ⅲ] and Western blot (Nestin, β-tubulin-Ⅲ, and MAP-2) were carried out to identify the neural cells derived from NSCs. The cell viabilities were measured by MTT assay and the quantity of lactate dehydrogenase (LDH) release in the medium.
ResultsIn the experimental group, the C17.2 NSCs bodies began to contract at 24 hours after induction, and the differentiated cells increased obviously with long synapse at 3 days after induction; in the control group, the cell morphology showed no obvious change at 24 hours, cell body shrinkage, condensation of nuclear chromatin, and lysis were observed at 3 days. The immunofluorescence staining showed that β-tubulin-Ⅲ and MAP-2 of C17.2 NSCs were positive at 5 days after induction, and Western blot suggested that the expression of Nestin protein declined significantly and the expressions of β-tubulin-Ⅲ and MAP-2 protein were increased in the experimental group, showing significant differences when compared with those in the control group and blank control group (P<0.05). The LDH release and the cell viability were 130.60%±6.86% and 62.20%±3.82% in the experimental group, and were 178.20%±5.44% and 18.00%±3.83% in the control group respectively, showing significant differences between 2 groups (P<0.05). The LDH release and the cell viability of experimental group and control group were significantly lower than those of blank control group (100%) (P<0.05).
ConclusionNeurotrophic factors from OECs play an important role in inducing C17.2 NSCs differentiation into neural cells and keeping the viability of differentiated cells after induction.
Objective To induce embryonic stem cell (ESC) to differentiate into endothel ioid cells using a simple adhesive culture method, and to provide a new cells seed source for vascular tissue engineering or cell therapy. Methods SV129-derived ESC were seeded at 2 × 104/cm2 and maintained undifferentiated on ESC culture medium in the presence of 1 000 U/mL leukaemia inhibitory factor (LIF). Embryoid body (EB) formatted when ESC cultured in suspension in the lack of LIF. At 4 days, EB was transferred to 0.1% gelatin coated dish and cultured with medium supplementary of VEGFto be induced differentiation. The characteristics of differentiated cells were determined by immunohistochemistry staining, flow cytometry (FCM), 1, 1-dioctadecyl-3, 3, 3, 3-tetramethyl indocarbocyanine-labeled acetylated low density l ipoprotein (DiIAc- LDL) takeup test, and TEM detection. Results Differentiated cells were morphologically characterized as endothel ial cells. They could takeup DiI-Ac-LDL, be stained positive by Flk-1 and CD31. The CD31 positive cells reached above 90% when measured by FCM. Furthermore, Weibel-Palade bodies were detected and tight junctions were found when differentiated cells were examined by TEM. Conclusion Using a simple adhesive culture method and by suppl ied with VEGF alone, ESCs can be induced to differentiate into endothel ioid cells. The differentiation method is simple and economic, and can provide seed cells for vascular tissue engineering or cell-therapy.
ObjectiveTo investigate the effect of burn on brown adipose tissue (BAT) in BALB/c mice.
MethodsForty 3-4 months old male BALB/c mice with initial body weight of (20±3) g were randomly divided into control group and burn group (n=20).BALB/c mice in burn group were subjected to a 30% total body surface area (TBSA) full-thickness thermal injury.BALB/c mice in control group were not treated.The body weight and temperature were observed before and after burn.At 7 days after burn,morphological changes of white adipose tissue (WAT) and BAT were observed,the gene and protein expressions of uncoupling protein 1 (UCP-1) were detected.
ResultsThere was no significant difference in the body weight and body temperature before burn (P>0.05).At 1,2,3,and 4 weeks after burn,the body weight was significantly lower in burn group than in control group (P<0.05).At 1,2,3,and 7 days after burn,the body temperature was significantly higher in burn group than in control group (P<0.05).At 7 days after burn,the weight of WAT was significantly reduced,and the weight of BAT was significantly increased in burn group (P<0.05); WAT and BAT cells became smaller,cell number increased,the cytoplasm and mitochondria appeared as compact.The UCP-1 gene and protein expressions of burn group were significantly higher than those of control group (P<0.05).
ConclusionBAT plays an important role in burn-induced hypermetabolism.
Objective Lots of metal ions accumulation and over-expression of receptor activator of NF-κB l igand (RANKL) around the prosthesis could be found in revision of total hip arthroplasty. To investigate the relationship between metal ions and aseptic loosening by observing the effects of Co2+ and Cr3+ ions on the expression of RANKL and osteoprotegerin(OPG) from osteoblast. Methods Osteoblasts were cultured in vitro at the density of 1 × 105 cells/mL, and were divided into 2 groups according to different culture solutions. In control group, osteoblasts were cultured with normal medium without CoCl2 and CrCl3. In experimental group, osteoblasts were cultured with the medium including CoCl2 (10 mg/ L) and CrCl3 (150 mg/L) solutions. The RT-PCR and ELISA methods were appl ied to detect the mRNA expression of RANKL and OPG and protein level at 24 and 48 hours after co-cultured, respectively. Results RT-PCR revealed that the mRNA expression of RANKL and OPG could be found in two groups at 24 and 48 hours after co-cultured, the expression was higher in the experimental group than in control group, especially the expression of RANKL, showing significant difference (P lt; 0.05). At 24 and 48 hours after co- cultured, the ratios of RANKL mRNA to OPG mRNA in the experimental group were 0.860 and 1.232, respectively, which were significantly higher than those in the control group (0.695 and 0.688,P lt; 0.05). ELISA revealed that the protein level of RANKL and OPG in experimental group were significantly higher than those in the control group (P lt; 0.05). Conclusion Co2+ and Cr3+ can stimulate the mRNA expressions of RANKL, OPG and secretion of those protein from osteoblasts, especially increase of the RANKL, which promotes the formation and activation of osteoblasts and the generation of aseptic loosening.
