Cell culture technology is the most commonly used method in the in vitro experiments at present. However, monolayer cell culture technology has been unable to meet the demand of the researchers. This is because that monolayer cell culture cannot mimic the cellular environment in which multiple cells interact with each other in the body. We cannot discuss the relationship of many cells, because we do not know the relationship between cells through a single kind of cell. So cell co-culture medicine arises at the historic moment for the demand. With the development of research method in recent years, cell co-culture method also has been improved in practice: from direct contact co-cultures to indirect contact co-cultures, from two-dimensional co-cultures to three-dimensional co-cultures. Cell co-culture method is closer to the human body. It is also more advantageous to study the interaction among cells. Nowadays, there are more researchers tend to select this method to study the physiological and pathological in vitro model, tissue engineering, and cell differentiation research. At the same time, it has become the focus of drug research and development, drug analysis, mechanism of drug action, and drug targets. This article will review the studies of cell co-culture method, summarize advantages and disadvantages of various methods, so as to promote improvement of cell culture methods, to build cells co-culture system that more close to human body, and build the in vitro model that simulate internal circulation of human body further.

BACKGROUND: Adipose tissue-derived mesenchymal stem cells (ADMSCs) have the multilineage differentiation potential, and are relatively easier to be obtained, thus they have attracted more and more attention as a new seed cell for cell engineering.OBJECTIVE: To observe the in vitro culture conditions of ADMSCs isolated from rat's subcutaneous adipose tissue, and identify them using immunohistochemical staining.DESIGN: An animal experiment.SETTING; Department of Cardiology, the General Hospital of Chinese PLA.MATERIALS: One healthy male Wistar rat of clean degree, 4 months old, weighing 200 g, was used. DMEM, fetal bovine serum were from GIBCO; Monoclone antibodies of rabbit-anti-rat CD13, CD34, CD44, CD45, CD105, D-related human leucocyte antigen (HLA-DR), factor-Ⅷ, vov Willebrand factor (VWF), Myosin, SABC kits and DAB staining kit from Wuhan Booster Biological Engineering, Co.,Ltd; Adeno-associated virus encoding green fluorescent protein from Vector Gene Technology Company Limited (Beijing).METHODS: The experiments were carried out in the Department of Internal Medicine, the General Hospital of Chinese PLA in October 2006. ① Cell isolation and culture: 0.3 g adipose tissue was cut from subcutaneous adipose tissue of Wistar rat's groin under aseptic condition, then minced and digested before culture, DMEM was changed at 2-3 days after plenty of fusiform-shap ed attached cells were observed under microscope, and the cell growth was observed. The cell concentration was adjusted to 2×107 L-1, then seeded into 96-well plate, and 100 μL for each well. From the second day, 3 wells were randomly selected every day, the cells were released with tripsin, and counted with blood cell counting chamber under inverted microscope. ② Cell viability assay: ADMSCs of passages 3 to 8 were added to DMSO freeze medium, and thawed after 2-4 weeks, and the cell viability was assessed by trypan blue dye exclusion. ③Immunohistochemical staining and identification: 2 ×107 L -1 cells were seeded to culture plate, then the immunohistochemical (SABC method) identification and Oil red O staining were performed to determine the cell surface antibodies of CD13, CD34, CD44, CD45, CD105, HLA-DR, factor-Ⅷ, HLA-DR and VWF. ④Lineage-specific differentiation and identification: The ADMSCs were plated on multi-well chamber and induced with lineage-specific media supplementation at least two weeks and identified by histologic/immunohistochemical assay of Oil red O for adipogenisis, alkaline phosphatase (ALP) stain for osteogenisis and Myosin monoclonal antibody for myogenisis. ⑤Transfected adenovirus carried green fluorescence protein (AD-GFP) medium: The fourth generation of ADMSCs were seeded on 96-well plate, 3 000 cells for each well, serum-free DMEM was changed after 24 hours, and added by AD-GFP at the same time, then transfected with different multiplicity of infection (MOI) of 1∶50, 1∶100, 1∶150 and 1∶200respectively, and then the transfection was observed.MAIN OUTCOME MEASURES: ① Results of cell isolation and culture; ② Cell viability after freezing and thawing; ③Results of immunohistochemical staining and identification; ④ Results of lineage-specific differentiation and identification;⑤ Results of transfected adenovirus carried AD-GFP.RESULTS: ① About 3.6×105 attached cells were obtained from 0.3 g subcutaneous adipose tissue, and these cells could be subcultured for passages in vitro with stable population doubling time. ② The cells were thawed after freezing for 2-3 weeks, and the trypan blue staining showed that the cell viability was above 90%. ③ The immunocytochemical staining showed that CD13, CD44, CD105 were positive and CD45, factor-Ⅷ, HLA-DR and VWF negative in different generations. ④ From the second generation, a few Oil red O positively stained cells were observed, which were obviously increased after prolonging the refreshing. After lineage-specific differentiation, the cells were all positive by Oil red O staining, ALP staining and Myosin immunohistochemical staining. ⑤ 72 hours after transfection, it was observed under fluorescence microscope that most cells were green fluorescence when the MOI value was 1∶200, the transfection was successful, and it was generally determined that the transfection rate was above 90%.CONCLUSION: A large number of ADMSCs with multilineage differentiation potential can be easily obtained from rat adipose tissue, osteoblast, myoblasts, they can be expanded in large quantity and stored in vitro for long time, AD-GFP were also successfully transfected.

Objective To investigate pulmonary capillary changes in patients with diabetes mellitus. Meth-otis Fifty-eight patients with diabetes mellitus were enrolled and forty-seven healthy subjects were taken as control. Diffusion capacity of carbonmonoxide (DLCO) and pulmonary ventilatory function were measured. DM and Vc were measured in twenty-one patients and twelve healthy subjects among them. Results FEV1/FVC was (81.02± 6.40) % in patients with diabetes mellitus and ( 81.20±6.96 ) % in controls, and FEV 1% was ( 102.03±14.40) in patients with diabetes mellitus and 103.94±11.42 in controls ,with no significant difference between patients with DLCO% was ( 72.79±19.85 ) % in patients with diabetes mellitus and ( 90.60±13.25 ) % in controls with a sig-patients whose course of disease was less than ten years,and DLCO% was (64.69±17.49)% in patients with dia-betes mellitus whose course of disease is equal or more than ten years and (80.90±18.98)% in patients whose course of disease is less than ten years,with significant difference between these two groups (t = 4.435, -3. 381, 13.88)% in patients with diabetes mellitas and (83.58±26.79)% in controls with a significant difference (t = 4. 612, P < 0.001 ). Vc was ( 61.40±52.84 ) ml in patients with diabetes mellitus and ( 66.99±19.63 ) ml in con-trols with no significant difference (P > 0.05 ), and Vc% was (78.05±64. 40)% in patients with diabetes mellitus and (79.33±23.32) % in controls, with no significant difference ( P > 0.05 ). Conclusions Diffusing capacity is decreased in patients with diabetes mellitus, which is related to the course of disease . DM decline is the main cause of DLCO decrease in patients with diabetes mellitus.

Objective:To observe the growth and development of the weaned mice fed with different levels of dietary zinc and to explore the expression of zinc transporter 3(ZnT3) mRNA induced by different dietary zinc intakes. Methods: Twenty male weaned mice (postnatal day 21) were divided into 4 groups: zinc deficient (ZD), zinc adequate(ZA), zinc supplemental (ZS) and pair fed(PF). Mice were fed with different levels of dietary zinc for 3 weeks (from postnatal day 21 to postnatal day 42) ;the zinc contents of ZD, ZA, ZS and PF group were 1 mg/kg, 30 mg/kg, 180 mg/kg and 180 mg/kg respectively. From postnatal day 21 to postnatal day 42, the diet intakes and weight of the mice were measured everyday. On postnatal day 42, the mice were sacrificed and tissues were immediately isolated and frozen lor RNA extraction. The serum zinc concentrations were measured by AAS and the expression of ZnT3 mRNA was determined by semiquantitative RT-PCR. Results: The dietary intakes and weight of ZD mice were much lower than that of other groups(P3

Objective To investigate the relationship between adiponectin and the first-phase of pancreatic P-cell insulin secretion in subjects with different statuses of glucose tolerance. Methods Thirty-seven patients with newly diagnosed type 2 diabetes mellitus (DM) , 30 patients with abnormal glucose tolerance (IGR) , and 40 normal control subjects (NGT) underwent intravenous glucose tolerance test (IVGTT). Fasting adiponectin and proinsulin (PI) was assayed by EL1SA. Fasting free fatty acid ( FFA) was measured by colorimetry. Insulin area under the curve ( AUC ) , incremental AUC (iAUC) from 0 min to 10 min, AIR3-5, homeostasis model assessment for insnlin resistance (HOMA-IR) , and for β cell function ( HOMA-p) were calculated. The relationship between adiponectin and AUC, iAUC, AIR3-5, proinsulin, FFA, and HOMA-IR was explored. Results (1) The levels of AUC, iAUC, AIR3-5, and adiponectin in DM group and IGR group were significantly lower than those in NGT group (P<0.05), reduced in DM group than those in IGR group(P<0.05). (2) The levels of PI in DM group and IGR group were significantly higher than that in NGT (P<0.05). (3) Adiponectin was positively correlated with HOMA-p,AUC,iAUC,AIR3-5, and HDL-C,while negatively correlated with proinsulin, HOMA-IR, and LDL-C. (4) Proinsulin was positively correlated with HOMA-IR. (5 ) Multiple regression stepwise analysis showed that adiponectin was independently associated with AUC. Conclusions Adiponectin was an independent factor affecting the first phase of pancreatic p-cell insulin secretion. Low adiponectin level could predict the dysfunction of the first phase pancreatic p-cell secretion as well as insulin resistance in patients with type 2 diabetes.

Objective To observe the effects of nourishing lung and kidney formulas on inflammatory response of alveolar epithelial cells stimulated by monocytes conditioned medium and study the anti-inflammatory mechanism of the formulas for the treatment of chronic obstructive pulmonary diseases (COPD).Methods The reproduction of inflammation models of A549 cells were stimulated by monocyte THP-1 cell strain conditioned medium.A549 cells were randomly divided into blank control group (20％ blank rabbits serum),model group (20％ blank rabbits serum+25.0％ THP-1 cell conditioned medium),nuclear transcription factor activator protein-1 (AP-1) pathway inhibitor T-5224group (20％ blank rabbits serum+25.0％ THP-1 cells conditioned medium+100 μmol/L T-5224),nourishing lung and kidney group (20％ rabbits serum with nourishing lung and kidney formulas+25.0％ THP-1 cells conditioned medium).The contents of interleukins (IL-6,IL-8),tumor necrosis factor-α (TNF-αα),matrix metalloprotein-9 (MMP-9) in cell culture supernatant were detected with enzyme linked immunosorbent assay (ELISA),the supernatant content of malondialdehyde (MDA) was detected with thibabituric acid (TBA) method,the total activity of superoxide dismutase (T-SOD) was detected with hydroxylamine method,and the activity of AP-1 pathway was detected with electrophoretic mobility shift assay (EMSA) method.Results Compared with the blank control group,the A549 cell proliferation were significantly increased at 24 hours,48 hours stimulation by 25.0％ cell conditioned medium (A value:24 hours was 0.41 ± 0.02 vs.0.37 ± 0.04,48 hours was 1.30 ± 0.09 vs.1.15 ± 0.19).Compared with the blank control group,the contents of IL-6,IL-8,TNF-αα,MMP-9,MDA,AP-1 expression were significantly increased in model group [IL-6 (ng/L):35.00±3.63 vs.23.15±1.72,IL-8 (ng/L):273.09± 164.36 vs.231.45±33.90,TNF-α(ng/L):51.61 ± 9.51 vs.28.87 ± 3.34,MMP-9 (ng/L):442.85 ± 78.86 vs.235.60 ± 14.62,MDA (μmol/L):6.90 ± 0.11 vs.6.01 ± 0.12,AP-1 expression (A value):2.260 ± 0.062 vs.1.000 ± 0.000],MDA/T-SOD ratio was increased (4.43 ± 0.05vs.3.96 ± 0.06).Compared with model group,the levels of IL-8 (ng/L:100.29 ± 17.03),TNF-α (ng/L:25.13 ± 0.46),AP-1 expression (A value:1.38 ± 0.02),and the MDA/T-SOD ratio (4.23 ± 0.23) in T-5224 group,and MMP-9 (ng/L:195.44±9.80),MDA (μmol/L:5.86±0.30),MDA/T-SOD ratio (3.56±0.41),AP-1 expression (A value:0.76 ± 0.01) in nourishing lung and kidney group were all reduced significantly (all P ＜ 0.05).Conclusion Nourishing lung and kidney formulas can suppress the inflammatory response through regulating the alveolar epithelial cells AP-1 signaling pathways.

Objective To study the effects of the different concentrations of ethanol extracts of Smilax China on ear edema in mice and granuloma in rats,and to provide an evidence for optimizing the extraction process. Methods Effects of different concentrations of ethanol extracts of Smilax China on the xylene-induced ear edema in mice and the cotton ball-induced granuloma hyperplasia in rats were tested . Results Compared with the model controls,70% ethanol extracts of Smilax China at high,medium and low doses significantly inhibited ear edema in mice (t=2. 58,P<0. 05;t=2. 28,P<0. 05;t=2. 17,P<0. 05) and reduced the granuloma hyperplasia in rats(t=5. 28,P<0. 01;t=5. 24,P<0. 01;t=5. 17,P<0. 01). Conclusion The 70% ethanol extracts of Smilax China at three doses present the most active antiinflammatory effect,confirmed in both mice ear edema and rats granuloma models.

Objective To investigate the expressions of insulin receptor substrate-1 (IRS-1) and insulin receptor sub-strate-2 (IRS-2) in adipocytes during catch-up growth in neonatal rats with intrauterine growth restriction (IUGR) and their correlations with the insulin resistance. Methods Sprague-Dawley rats (clean grade) were randomly divided into control group and food-restricted group after fertilization. Food-restricted group were received about 30%of food amount consumed in control group every day through the whole pregnant period to establish IUGR animal model, and were fed increased amount of breast-milk from postnatal day 1 to 21 to establish the period of catch-up growth in IUGR animal model (IUGR-CG). Fasting serum glu-cose, insulin and triglyceride were measured in blood from heart ventricles of 4-week old SD rats and insulin resistance index was calculated. Pre-adipocytes and mature adipocytes were obtained from SD rats at different age (1-week, 3-week, 5-week and 7-week old) and the former were induced to differentiate toward mature adipocytes. The levels of IRS-1, IRS-2 in the two kinds of mature adipocytes were detected by Real-Time PCR and Western blot. Results The expression levels of IRS-1, IRS-2 mRNA in mature adipocytes of IUGR-CG rats were signiifcantly lower than those of IUGR rats at 5-weeks and 7-weeks old (P<0.05) while the ex-pression levels of IRS-1, IRS-2 mRNA in differentiated adipocytes of IUGR-CG rats were signiifcantly lower than those of IUGR rats at 5-weeks old (P<0.05). The expression levels of IRS-1, IRS-2 protein in two kinds of adipocytes (mature and differentiated adipocytes) of IUGR-CG rats were signiifcantly lower than those of IUGR rats from postpartum week 1 through 7 (P<0.05). Conclusions IRS-1 and IRS-2 expression levels are downregulated in adipocytes during catch-up growth of IUGR rats, which may be closely related with insulin resistance.

Objective To investigate the influence of rehmannia glutinosa oligosaccharide(RGOs)on apoptosis of human adipose tissue-derived mesenchymal stromal cells(ADMSCs)induced by hydrogen peroxide(H2O2).Methods Cultured human ADMSCs were randomly divided into three groups as the normal group(group N,without any treatment),H2O2 group(group H,treated with 0.1 mmol/L H2O2),and RGOs group(group R,treated with 0.2g/L RGOs plus 0.1 mmol/L H2O2).After 1 h,6 h and 24 h,morphological changes of ADMSCs apoptotic were observed,the apoptotic rate was determined by flow cytometry.Results After 1 h,6 h and 24 h,the apoptotic rate of group H was significantly higher than that of the group N and group R(P<0.05),and the apoptotic rate of group H was significantly higher than that of the group R(P<0.05).Conclusion RGOs can attenuate apoptosis of human ADMSCs induced by H2O2.

Objective To explore the protective effects of quercetin on damage induced by oxidative stress and to clari?fy its molecular mechanism. Methods Chang liver cell cultures were randomly divided into control groups, H2O2 group and 3 doses of quercetin groups. Cell survival rate was detected with MTT. Cell apoptotic rate was measured by FACS(Fluores?cence-activated cell sorting). Intracellular reactive oxygen species (ROS) level in Chang liver cells were tested by flow cy?tometer. The DCF fluorescence intensity of DCFH-DA-stained intracellular ROS was observed by fluorescence microscope. The levels of malondialdehyde (MDA), superoxide dismutase(SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were determined in liver cells using commercial available kits. The expression of Nrf2 were detected by Western blot. Re?sults Compared with control, cell survival rate and levels of SOD, CAT and GSH-Px decreased significantly in H2O2 group (P < 0.05 ),while cell appotosis rate, content of MDA and mean fluorescence intensity(MFI) increased in H2O2 group (P <0.05). In comparison with H2O2, expression of Nrf2 protein was higher in all three quercetin treatment groups (P<0.05). Con?clusion Quercetin protected Chang liver cells from H2O2-induced oxidative stress, which may be caused by the increased ex?pressions of down stream antioxidant genes via activating the Nrf2-ARE signaling pathway.