On the basis of established JF305 cell line from human pancreatic cancer at this university, cell clone technique, cell electrophoresis, flower cytometer, and cancer orthotopically implanted nude mice technique were used to establish the sublines with different metastatic potential from human pancreatic cancer line-JF305 and the nude mice model implanted orthotopically with human pancreatic cancer monoclonal sublines with different metastatic potential. The results showed that the monoclonal cell sublines with different metastatic potential from human pancreatic caner-JF305 and the nude mice model implanted orthotopically with the sublines, would provided a useful method to study the metastatic mechanism of human pancreatic cancer.
ObjectiveTo investigate the mechanism of muscle-derived cells (MDCs) in repairing sciatic nerve defects in mice by observing the early growth of damaged peripheral nerves.MethodsThe hind limb skeletal muscles of mice carrying enhanced green fluorescent protein (EGFP) was collected to extract and culture EGFP-MDCs to P1 generation for later experiments. Five-mm-long nerve defects were created in the right sciatic nerves of C57BL/6 mice to establish a peripheral nerve defect model. The two stumps of sciatic nerve were bridged with 7-mm-long polyurethane (PUR) conduit. For the MDC group, EGFP-MDCs were injected into the PUR conduit. The PUR group without EGFP-MDCs was used as the negative control group. At 1 and 2 weeks after operation, the proximal and distal nerve stumps of the surgical side were collected to generally observe the early growth of nerve. Immunofluorescence staining of S100β, the marker of Schwann cells, was performed on longitudinal frozen sections of nerve tissues to calculate the maximum migration distance of Schwann cells, and observe the source of the Schwann cells expressing S100β. Immunofluorescence staining of phosphorylated erb-b2 receptor tyrosine kinase 2 (p-ErbB2) and phosphorylated focal adhesion kinase (p-FAK) in transverse frozen sections of nerve tissue was performed to calculate the positive rates of both proteins.ResultsThe general observation showed that the proximal and distal stumps of the surgical side in PUR group were not connected at 1 and 2 weeks after operation, while the bilateral nerve stumps in the MDC group were connected at 2 weeks after operation. Immunofluorescence staining showed that the Schwann cells expressing S100β in proximal and distal nerve stumps of PUR group and MDC group was not connected at 1 week after operation. At 2 weeks after operation, the Schwann cells expressing S100β in the two nerve stumps of the MDC group were connected, but not in the PUR group. At 2 weeks after operation, the sum of the maximum migration distance of Schwann cells in the regenerated nerve in both two groups was significantly increased when compared with that in each group at 1 week after operation, and that of MDC group was significantly higher than that in the PUR group at both 1 and 2 weeks after operation, the differences were all significant (P<0.05). At 1 week after operation, the positive rates of p-ErbB2 and p-FAK in the proximal nerve stump of MDC group were significantly higher than those in PUR group (P<0.05). There was no significant difference in the positive rate of p-ErbB2 of proximal stump between the two groups at 2 weeks after operation (t=0.327, P=0.747), while the positive rate of p-FAK of MDC group was significantly higher than that of PUR group (t=4.470, P=0.000). At 1 and 2 weeks after operation, the positive rates of p-ErbB2 and p-FAK in the distal stump of MDC group were significantly higher than those in PUR group (P<0.05). At 1 and 2 weeks after operation, part of Schwann cells expressing S100β, which were derived from EGFP-MDCs, could be observed in the regenerated nerves of MDC group.ConclusionMDCs can promote the phosphorylation of ErbB2 and FAK in the nerve stumps of mice, and promote the migration of Schwann cells. MDCs can be differentiated into cells expressing the Schwann cell marker S100β, or as other cellular components, to involve in the early repair of peripheral nerves.
ObjectiveTo summarize the common mouse models and the latest research progress in the basic research of colorectal cancer, introducing advantages, disadvantages and applications of these various models, provide references for the researchers in the selection of mouse models for their experiments.MethodRetrieved the related literatures from databases including PubMed, Web of Science, CNKI and WanFang, and after reading the literatures, different methods were sorted out, analyzed and summarized.ResultsThe mouse models commonly used in colorectal cancer research include the cell-derived xenograft (CDX), patient-derived xenograft (PDX), chemical reagent-induced tumor in situ, transgenic mice (ApcMin/+ mice), tumor cells derived from mice themselves were inoculated to the normal mice, and models of colorectal metastatic tumors (including liver, lung, abdomen and bone metastases, etc.). The CDX model cost shorter time to establish, and the PDX model restored the authentic phenotype of the tumor in patients, but the tumor were both colonized under the skin of nude mice, which lacked authenticity tumor microenvironment. The colorectal cancer in mice induced by chemical reagents and genetically engineered mice imitated the development of colorectal tumor in the situ intestine of mouse, but both of them were time-consuming. The model established by the tumor of mouse own was convenient for basic immune research of colorectal cancer, but the disadvantage was the unreal tumor microenvironment. The colorectal cancer metastasis model was an essential model for the study of the mechanism and treatment in metastasis colorectal tumor, but its establishment required higher operating skills and required the image examination to determine the whether the metastasis tumor was successfully generated or not.ConclusionsDifferent mouse models of colorectal cancer have different emphases, advantages and disadvantages. Researchers need to make accurate selection according to the research purpose and design needs.
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 explore the effect of chronic unpredictable mild stress (CUMS) on the reproductive function of mice and provide a suitable animal model for reproduction and stress.
MethodsA total of 240 female Kunming mice were feed for 5 days, and then divided randomly into the control group (n=90) and experimental group (n=150). The mice in the experimental group were stressed by 9 chronic mild unpredictable stress factors for 4 weeks and validated by open field test and sucrose consumption test. We administrated pregnant mare serum gonadotropin (PMSG)/human chorionic gonadotropin (HCG) for induction of superovulation and observed the ovarian response and embryo development potential.
ResultsAfter 4-week CUMS stimulation, the weight gain, 2% sugar consumption test and open field test were significantly different between the mice in two groups (P>0.05). After PMSG/HCG was administrated, the antra follicles and preovulatory follicles significantly reduced significantly in the experiment group than that in the control group (P<0.05); the number of oocytes, fertilization rate, 2-cell embryos, D4 embryos, blastocysts, high quality embryo rate and D5 bed points were all significantly decreased in the experiment group than those in the control group (P<0.05).
ConclusionThe CUMS female Kunming mice model is a kind of emotional stress animal model with low reproductive function, which is effective, operable and repeatable; it could be used for further study on the mechanism of reproductive medicine.
Objective
To study the transfection and expression of pleiotrophin (Ptn) gene in mice adipose-derived stem cells (ADSCs) so as to provide a new approach for the treatment of ischemic injury.
Methods
ADSCs from clean inbred C57BL/6W mice (weighing, 15-20 g) were isolated and cultured in vitro. The cell surface markers (CD29 and CD44) of ADSCs were identified by flow cytometry. The ADSCs were transfected with plasmid pIRES2-LEGFPN1 (containing Ptn gene coding sequence) as experimental group (group A) and with plasmid pLEGFP-N1 (containing GFP gene coding sequence) as control group (group B). After ADSCs were transfected by different plasmids respectively, the cells containing Ptn gene were selected by G418 (the best selected concentration was 200 μg/mL), and the immunophenotype of the cells was identified by flow cytometry after transfection. Meanwhile, real-time fluorescence quantitative PCR and Western blot were used to analyse the expression levels of Ptn mRNA and PTN protein in selected cells.
Results
The mice ADSCs were isolated and cultured successfully in vitro. The positive rates of the cell surface markers CD29 and CD44 of ADSCs were 99.5% and 95.8%, respectively; the double positive rate of CD44 and CD29 was 93.6%. The positive rates of the cell surface markers CD29 and CD44 of ADSCs were 99.1% and 95.6%, respectively after transfection of Ptn gene; the double positive rate of CD44 and CD29 was 93.4%. The expression levels of Ptn gene and PTN protein in group A were significantly higher than those in group B (P lt; 0.05).
Conclusion
The ADSCs can be stablely transfected by Ptn gene, the transfected ADSCs can express PTN protein highly, which is a new idea for tissue engineering of vascular reconstruction.
ObjectiveTo study microRNA (miRNA) involved in the regulation of sinus cell differentiation by comparing sinus node, atrial myocardium, and ventricular myocardium specific miRNA expression profile differences in Kunming mice.
MethodsA total of 180 Kunming mice, aged 60-90 days and weighing 35-45 g, were selected without gender differences after the method of anatomical localization for sinus node had been confirmed by preliminary experiments in another 10 Kunming mice. All the sinus node, atrial myocardium, and ventricular myocardium tissue from 180 mice were dissected and frozen by liquid nitrogen. The structure of tissue was observed by HE staining. Total RNA were extracted and quality-controlled before hybridize with miRNA chip. The chips with miRNA were used to screen specific miRNAs; and correlation analysis of gene function was done.
ResultsThe area of mice sinus node located at juncture of the superior vena cava and the right atrium junction with crista as its longitudinal axis, ranged 2.0 mm×1.5 mm×1.0 mm. HE staining showed the sinus cells were less, with no stripes, lightly stained cytoplasm, large and round nucleus, and there were much fibrous connective tissue around cells with a visible sinus node artery. The miRNA microarray results showed that compared with atrial myocardium and ventricular myocardium, there were 39 differentially expressed miRNAs in sinus node, including 12 up-regulated miRNAs and 27 down-regulated miRNAs. Based on the regulatory networks of differential miRNA and target gene, the regulatory miRNA was obtained.
ConclusionThe differentially expressed miRNA in mice sinus node possibly may be involved in the regulation of sinus cell differentiation.
ObjectiveTo study the effect and mechanism of lipopolysaccharide (LPS) on osteoclasts formation and its bone resorption function.MethodsBone marrow-derived macrophages (BMMs) were extracted from the marrow of femur and tibia of 4-week-old male C57BL/6 mice. Flow cytometry was used to detect BMMs. The effect of different concentrations of LPS (0, 100, 200, 500, 1 000, 2 000 ng/mL) on BMMs activity was examined by cell counting kit 8 (CCK-8) activity test. In order to investigate the effect of LPS on osteoclastogenesis, BMMs were divided into macrophage colony-stimulating factor (M-CSF) group, M-CSF+receptor activator of nuclear factor κB ligand (RANKL) group, M-CSF+RANKL+50 ng/mL LPS group, M-CSF+RANKL+100 ng/mL LPS group. After the completion of culture, tartrate resistant acid phosphatase (TRAP) staining was used to observe the formation of osteoclasts. In order to investigate the effect of LPS on the expression of Connexin43, BMMs were divided into the control group (M-CSF+RANKL) and the LPS group (M-CSF+RANKL+100 ng/mL LPS); and the control group (M-CSF+RANKL), 50 ng/mL LPS group (M-CSF+RANKL+50 ng/mL LPS), and 100 ng/mL LPS group (M-CSF+RANKL+100 ng/mL LPS). The expressions of Connexin43 mRNA and protein were detected by Western blot and real-time fluorescent quantitative PCR, respectively. In order to investigate the effect of LPS on osteoclast bone resorption, BMMs were divided into M-CSF group, M-CSF+RANKL group, M-CSF+RANKL+50 ng/mL LPS group, and M-CSF+RANKL+100 ng/mL LPS group. Bone absorption test was used to detect the ratio of bone resorption area.ResultsThe flow cytometry test confirmed that the cultured cells were BMMs, and CCK-8 activity test proved that the 100 ng/mL LPS could promote the proliferation of BMMs, showing significant differences when compared with the 0, 200, 500, 1 000, and 2 000 ng/mL LPS (P<0.05). TRAP staining showed no osteoclast formation in M-CSF group. Compared with M-CSF+RANKL group, the osteoclasts in M-CSF+RANKL+50 ng/mL LPS group and M-CSF+RANKL+100 ng/mL LPS group were larger with more nuclei, while the osteoclasts in M-CSF+RANKL+100 ng/mL LPS group were more obvious, and the differences in the ratio of osteoclast area between groups were statistically significant (P<0.05). Western blot result showed that the relative expression of Connexin43 protein in LPS group was significantly higher than that in control group (P<0.05). Real-time fluorescent quantitative PCR showed that the relative expression of Connexin43 mRNA in control group, 50 ng/mL LPS group, and 100 ng/mL LPS group increased gradually, and the differences between groups were statistically significant (P<0.05). Bone resorption test showed that osteoclast bone resorption did not form in M-CSF group, but the ratio of bone resorption area increased gradually in M-CSF+RANKL group, M-CSF+RANKL+50 ng/mL LPS group, and M-CSF+RANKL+100 ng/mL LPS group, and the differences between groups were statistically significant (P<0.05).ConclusionLPS at concentration of 100 ng/mL can promote the expression of Connexin43, resulting in increased osteoclastogenesis and enhanced osteoclastic bone resorption.
ObjectiveTo explore the possibility of constructing tissue engineered adipose by adipose tissue derived extracellular vesicles (hAT-EV) combined with decellularized adipose tissue (DAT) scaffolds, and to provide a new therapy for soft tissue defects.MethodsThe adipose tissue voluntarily donated by the liposuction patient was divided into two parts, one of them was decellularized and observed by HE and Masson staining and scanning electron microscope (SEM). Immunohistochemical staining and Western blot detection for collagen type Ⅰ and Ⅳ and laminin were also employed. Another one was incubated with exosome-removed complete medium for 48 hours, then centrifuged to collect the medium and to obtain hAT-EV via ultracentrifugation. The morphology of hAT-EV was observed by transmission electron microscopy; the nanoparticle tracking analyzer (NanoSight) was used to analyze the size distribution; Western blot was used to analyse membrane surface protein of hAT-EV. Adipose derived stem cells (ADSCs) were co-cultured with PKH26 fluorescently labeled hAT-EV, confocal fluorescence microscopy was used to observe the uptake of hAT-EV by ADSCs. Oil red O staining was used to evaluate adipogenic differentiation after hAT-EV and ADSCs co-cultured for 15 days. The DAT was scissored and then injected into the bilateral backs of 8 C57 mice (6-week-old). In experimental group, 0.2 mL hAT-EV was injected weekly, and 0.2 mL PBS was injected weekly in control group. After 12 weeks, the mice were sacrificed, and the new fat organisms on both sides were weighed. The amount of new fat was evaluated by HE and peri-lipoprotein immunofluorescence staining to evaluate the ability of hAT-EV to induce adipogenesis in vivo.ResultsAfter acellularization of adipose tissue, HE and Masson staining showed that DAT was mainly composed of loosely arranged collagen with no nucleus; SEM showed that no cells and cell fragments were found in DAT, and thick fibrous collagen bundles could be seen; immunohistochemical staining and Western blot detection showed that collagen type Ⅰ and Ⅳ and laminin were retained in DAT. It was found that hAT-EV exhibited a spherical shape of double-layer envelope, with high expressions of CD63, apoptosis-inducible factor 6 interacting protein antibody, tumor susceptibility gene 101, and the particle size of 97.9% hAT-EV ranged from 32.67 nmto 220.20 nm with a peak at 91.28 nm. Confocal fluorescence microscopy and oil red O staining showed that hAT-EV was absorbed by ADSCs and induced adipogenic differentiation. In vivo experiments showed that the wet weight of fat new organisms in the experimental group was significantly higher than that in the control group (t=2.278, P=0.048). HE staining showed that the structure of lipid droplets in the experimental group was more than that in the control group, and the collagen content in the control group was higher than that in the experimental group. The proportion of new fat in the experimental group was significantly higher than that in the control group ( t=4.648, P=0.017).ConclusionDAT carrying hAT-EV can be used as a new method to induce adipose tissue regeneration and has a potential application prospect in the repair of soft tissue defects.
As a relatively novel technique for drug delivery, the needle-free injection technique is characterized by transporting the drug liquid to the designated subcutaneous position through a high-speed micro-jet. Although this technique has been applied in many fields, the research on its drug dispersion mechanism and injection performance is insufficient. The presented study aims to identify critical parameters during the injection process and describe their influence on the injection effect. The injection completion rate and performance of a needle-free injector under various operating conditions were compared based on mouse experiments. The results show that the nozzle diameter imposes a more significant influence on jet characteristics than other injection parameters. Moreover, the injection completion rate increases with the nozzle diameter. The nozzle diameters of 0.14 mm and 0.25 mm correspond to injection completion rates of 89.7% and 95.8%, respectively. Furthermore, by analyzing the rate of blood glucose change in the tested mice, it is found that insulin administration through the needle-free injection can achieve a drug effect duration longer than 120 min, which is better than that obtained using conventional needle-syringe technique. In summary, the obtained conclusions can provide an important reference for the optimal design and extending application of the air-powered needle-free injector.
