BACKGROUND:Spleen has the functions of blood storage,hematopoiesis,and immunity.With the increase of age,the structural degeneration and functional decline of spleen lead to the impairment of immune system function,thus accelerating the aging process of the body.The treatment of spleen aging in tree shrews with highly active umbilical cord mesenchymal stem cells has not been reported. OBJECTIVE:To explore the intervention effect and mechanism of highly active umbilical cord mesenchymal stem cells on spleen aging in tree shrews. METHODS:Highly active umbilical cord mesenchymal stem cells were isolated,cultured,and obtained from the umbilical cord tissue of newborn tree shrews by caesarean section.The differentiation abilities of adipogenesis,osteogenesis,and chondrogenesis were detected by three-line differentiation kit.Cell cycle and surface markers were detected by flow cytometry.The second generation of highly active umbilical cord mesenchymal stem cells were transfected with Genechem Green Fluorescent Protein with infection complex values of 100,120,140,160,180,and 200,respectively,to screen the best transfection conditions.After transfection,the fourth generation of highly active umbilical cord mesenchymal stem cells was injected into the tail vein of tree shrews in the elderly treatment group.The young control group and the aged model group were not given special treatment.After 4 months of treatment,the spleen tissue was taken and the structure of the spleen was observed by hematoxylin-eosin staining.β-Galactosidase staining was used to detect the activity of aging-related galactosidase.Immunohistochemical staining was used to detect the expression levels of p21 and p53 proteins.Ki67 and PCNA immunofluorescence staining was used to detect cell proliferation activity.Immunofluorescence staining was used to detect the expression levels of spleen autophagy protein molecules Beclin 1 and APG5L/ATG5.Reactive oxygen species fluorescence staining was used to detect the content of reactive oxygen species in spleen tissue.CD3 immunofluorescence staining was used to detect the change of the proportion of total T lymphocytes.The secretion levels of interleukin 1β and transforming growth factor β1 in spleen were detected by enzyme linked immunosorbent assay.The distribution of highly active umbilical cord mesenchymal stem cells labeled with green fluorescent protein in spleen tissue was observed by DAPI double staining of nucleus. RESULTS AND CONCLUSION:(1)Highly active umbilical cord mesenchymal stem cells grew in a short spindle shape with fish-like growth,with a large proportion of G0/G1 phase,and had the potential to differentiate into adipogenesis,osteogenesis,and chondrogenesis.(2)Multiplicity of infection=140 and transfection for 72 hours were the best conditions for labeling tree shrews highly active umbilical cord mesenchymal stem cells with Genechem Green Fluorescent Protein.(3)Compared with the aged model group,in the aged treatment group,the spleen tissue cells of tree shrews were arranged closely,and the area of white pulp was increased(P<0.01);the boundary between red pulp and white pulp was clear;the proportion of germinal centers did not show statistically significant difference(P>0.05).The activity level of galactosidase related to spleen tissue aging was decreased(P<0.001),and the expression levels of aging protein molecules p21 and p53 were down-regulated(P<0.001).The expression levels of proliferation-related molecules Ki67 and PCNA were up-regulated(P<0.001,P<0.05);expression levels of autophagy-related molecules Beclin 1 and APG5L/ATG5 were up-regulated(P<0.001),and the content of reactive oxygen species decreased(P<0.001),and the proportion of CD3+T cells increased(P<0.05).The secretion level of interleukin 1β in the aging-related secretion phenotype decreased(P<0.001);no significant difference was found in transforming growth factor β1 level(P>0.05).Compared with the young control group,the above indexes were significantly different in the elderly treatment group(P<0.05).(4)Green fluorescent cells labeled with green fluorescent protein were observed in spleen tissue of tree shrews the elderly treatment group by frozen tissue section observation.The results show that intravenous infusion of highly active umbilical cord mesenchymal stem cells can migrate to spleen tissue,inhibit the production of reactive oxygen species,down-regulate the expression of aging-related proteins,induce autophagy,promote cell proliferation,reduce chronic inflammation,and then improve the structure and function of spleen tissue.

Objective To elucidate the prediction ability of monocyte monolayer assay(MMA)used in hemolytic dis-ease of fetus and newborn(HDFN)caused by IgG anti-M.Methods Plasma from eight pregnant women containing IgG an-ti-M were collected,and were divided into two groups(4 cases with HDFN,with severe clinical symptoms such as fetal hy-drops,and 4 cases without HDFN)according to the clinical outcomes.M antigen positive cells were sensitized with dithioth-reitol(DTT)treated plasma from eight pregnant women respectively.MMA was performed by coincubation with monocytes and sensitized M cells,along with negative and positive control set up.T-test was conducted to compare the difference in phagocytic efficiency between two groups.Results The phagocytic efficiency in group with HDFN were 15.37%,13.05%,9.17%and 24.50%respectively,with the mean value of 15.52%,while the group without HDFN were 8.74%,11.07%,5.12%and 6.23%respectively,with the mean value of 7.79%.There was no significant difference in phagocytic efficiency between two groups(P>0.05).The mean values of both groups were not significantly different from the negative control(P>0.05),but both were significantly lower than positive control(P<0.05).Conclusion The low phagocytic efficiency couldn't convince that the MMA is an effective predictor for the HDFN caused by IgG anti-M,indicating that another mech-anism might be responsible for it rather than monocyte phagocytosis.The assessment of the peak systolic velocity in middle cerebral artery of the fetal should be considered in the management for pregnant women who produce IgG anti-M to estimate the situation of fetal anemia.

In the field of biomedicine,two-dimensional(2D)cell lines and animal models have played an im-portant role in the study of cell pathways and drug targets.However,due to species differences between humans and other animals,and the lack of hierarchy,cellular diversity,and cell-cell or cell-matrix interactions,2D cell lines could not ful-ly reflect what cells actually look like in the human body.Organoids are three-dimensional(3D)in vitro culture models de-rived from autologous tissue stem cells,which make up for the defects of 2D culture and can simulate the structure and function of real human organs to a certain extent,providing new ideas for disease diagnosis and treatment.Among them,lung organoids(LO)are a typical case studying the development process of human lung and the generation principle of lung diseases.Relevant studies have provided help for the treatment of pulmonary fibrosis,lung cancer,lung injury and other diseases.This paper aims to summarize and analyze the research progress of lung organoids in recent years,and fur-ther summarize the application of LO in the diagnosis and treatment of lung diseases.

【Objective】 To establish an experimental method for detecting phagocytosis of sensitized red blood cells in vitro by flow cytometry. 【Methods】 Mononuclear cells were isolated from the peripheral blood of blood donors and cultured in a cell incubator for 1 hour, and then adherent monocytes were isolated and obtained. Di^b-positive red blood cells (RBCs) were labeled with PKH26 and then sensitized with IgG anti-Di^b. The sensitized RBCs were added to monocytes for in vitro phagocytosis assay. Monocytes were labeled with FITC anti-human CD14, then phagocytosis was measured by flow cytometry, and the phagocytic efficiency was calculated. The method was used to detect the phagocytic efficiency of monocytes on human IgG anti-D sensitized RBCs with different titers. 【Results】 The phagocytic efficiency of monocytes was averaged at 5% (1.2%~7.6%, SD 3.30) versus 81% (71.4%~92.7%, SD 8.65) in the negative versus positive control group, respectively. Phagocytic activity of monocytes mediated by anti-D was correlated with the antibody titer. The phagocytosis efficiency was within 10% when the antibody titer was lower than 32 and increased sharply when the titer was between 32 to 128, it entered a plateau and stabilized at 80% at the titer above 256. 【Conclusion】 A detection platform for detecting phagocytosis-sensitized RBCs in vitro by flow cytometry has been successfully established. It can be used to assess the clinical significance of red blood cell allotype or autologous IgG antibodies.

Objective: To establish a fluorescence method based on turncated aptamer for the determination of bisphenol A in water. Methods: The bisphenol A truncated aptamer containing 38 bases was selected as a recognition module, and was modified with the fluorophore 6-FAM at the 5'end. The 3'end of the complementary sequence cDNA was modified with the quencher DABCYL. The standard solutions of bisphenol A and interfering compounds were configured. The detection system was established after optimizing the number of bases in cDNA, the concentration ratio of truncated aptamer to cDNA, the incubation temperature and time, and the pH of the buffer. The specificity and recovery experiments were carried out. Results: When the complementary sequence cDNA included 9 bases, the concentration ratio of the truncated aptamer to cDNA was 1:1.5, the pH value of the buffer solution was 7.5, the cDNA was incubated at 55 ℃ for 60 minutes, in the concentration range of 10-75 pmol/L, the linear regression equation was y=2 230.7x+110 825, the correlation coefficient was 0.926. The limits of detection was 3.3 pmol/L. The difference values of fluorescence intensity between tetrabromobisphenol A, estradiol, estriol, bisphenol S and bisphenol A were obviously different, so there was no significant interference to the test result. The recovery rates were 97.8%, 98.8% and 102.3% with the spiked concentrations of 20.0, 40.0 and 60.0 pmol/L. The relative standard deviations were 4.4%, 2.1% and 2.6% (n=5), respectively. Conclusion The fluorescence method based on turncated aptamer has the advantages of easy operation, high sensitivity and specificity, which can be used for the determination of bisphenol A in water.

BACKGROUND: Studies have shown that umbilical cord mesenchymal stem cells are ideal seed cells for tissueengineering research.OBJECTIVE: To isolate, culture and identify tree shrew umbilical cord mesenchymal stem cells, in order toestablish a standardized tree shrew umbilical cord mesenchymal stem cell lines.METHODS: Caesarean-isolated tree shrew umbilical cord samples were used to isolate and culture umbilical cordmesenchymal stem cells using tissue explant adherent method. Flow cytometry assay was used to detect cellsurface markers. Osteogenic and adipogenic induction media were used to induce umbilical cord mesenchymalstem cells to differentiate into osteoblasts and adipocytes.RESULTS AND CONCLUSION: The cultured umbilical cord mesenchymal stem cells expressed CD90 and CD105 with the positive rate of 99.9% and 99.8% respectively. Hematopoietic stem cell marker CD34 expression ratewas 0.0% and the endothelial cell marker CD31 expression rate was 0.7%, in line with the characteristics of umbilicalcord mesenchymal stem cell surface markers. Calcium nodules by alizarin red staining and lipid droplets by oil red Ostaining were observed in the induced cells. These experimental findings indicated that umbilical cord mesenchymalstem cells from tree shrews capable of osteogenic and adipogenic differentiation were successfully isolated and cultured.

Humanumbilicalveinendothelialcells(HUVECs)weretreatedwith3nmol/Lliraglutidefor10, 15, 30, 45, 60, 90, 120, 150, 180, 210, 240, and 270 minutes at the concentrations of 5. 5 or 30 mmol/L glucose. Western blot analysis was used to detected protein expression and phosphorylation of insulin receptor substrates-1 ( IRS-1 ) and endothelial nitric oxide synthase ( eNOS ) . The results showed that the baseline level of phosphorylated-eNOS/eNOS was lower in high glucose group than that in normal group(0. 239 ± 0. 016 vs 0. 400 ± 0. 02,P<0. 05). Liraglutide time-dependently increased phosphorylated-eNOS/eNOS and phosphorylated-IRS-1/IRS-1 levels at 5. 5 or 30 mmol/L glucose.

AIM:To explore the effects of confluent endothelial progenitor cells (EPCs) derived from young and aged rats on the phenotype conversion, proliferation and migration of vascular smooth muscle cells ( SMCs) .METH-ODS:Mononuclear cells were obtained from the bone marrow of young (1~2 month old) and aged (19 to 26 month old) Sprague-Dawley rats and cultured with medium DMEM/F12 ( containing 15% fetal bovine serum, endothelial cell growth supplements (ECGs) 100 g/L, 1 ×105 units/L of penicillin and streptomycin, respectively).EPCs were characterized as double positive for DiI-Ac-LDL uptake and lectin binding.Abdominal aorta was obtained from 1 to 2 month old Sprague-Dawley rats.Vascular SMCs were cultured by tissue explant method and identified byα-SM-actin immunofluorescence.In transwell co-culture system, the confluent EPCs located in the upper chamber and SMCs were seeded on the lower cham-ber.The experiments were divided into passage 3 SMCs group (P3), passage 4 SMCs group (P4), passage 4 SMCs co-culture with EPCs derived from young rats group (P4YE) and passage 4 SMCs co-culture with EPCs derived from aged rats group (P4AE).The protein expression ofα-SM-actin and osteopontin was detected by Western blotting.[3H]-TdR incor-poration assay was used to determine the proliferation.SMC migration was analyzed by scratch wound healing assay.RE-SULTS:Compared with P3 group,α-SM-actin expression in P4 group significantly decreased and osteopontin protein ex-pression obviously increased, whereas no significant change was found in P4YE group.Compared with P4 group, confluent EPCs derived from young and aged rats both markedly increased α-SM-actin and decreased osteopontin expression in P4 SMCs.Compared with aged rat-derived EPCs, young rat-derived EPCs were more effectively to induce a delayed SMC phe-notype transition (from contractile phenotype to a synthetic phenotype), and to inhibit SMC proliferation and migration. CONCLUSION:Co-culture of confluent EPC induces a delayed vascular SMC phenotype transition and inhibits SMCs pro-liferation and migration.Young rat derived EPCs are more effective to induce a delayed vascular SMC phenotype transition and has stronger inhibitory effects on SMCs proliferation and migration compared with that derived from aged rats.

Objective To establish a method for isolation of cynomolgus monkey umbilical cord mesenchymal stem cells.Methods Fresh cynomolgus monkey umbilical cord was directly minced into pasty fine pieces, and the pieces were cultured in tissue flask with DMEM/F12 medium supplemented with 10% fetal bovine serum.The morphological characteristics of the resulting cells were examined, and their expression of mesenchymal cell surface markers were analyzed by flow cytometry.The multidifferentiation potential was examined in vitro, too.Results The fibroblast-like cells were successfully isolated from the fresh umbilical cord by an adherent culture procedure.These adherent cells expressed mesenchymal markers including CD29, CD44, and CD90, and also could be induced to differentiate into adipocytes, osteoblasts and chondrocytes.Conclusion Mesenchymal stem cells can be isolated from fresh cynomolgus monkey umbilical cord by using an adherent culture procedure.

Objective To investigate the influences of grape seed proanthocyanidin extract (GSPE) on cardiovascular system, nervous system and respiratory system of experimental animals, and provide general pharmacological data for further research and application. Methods The influences of GSPE on blood pressure, heart rate, electrocardiogram, breathing frequency and tidal volume in anesthetic dogs after duodenal administration were observed, the impacts on spontaneous activity, coordinated motion, and the sleep situation with threshold dose and subthreshold dose of pentobarbital sodium in mice after intragastric administration were observed. Results GSPE showed no side effects on blood pressure, heart rate, electrocardiogram, breathing frequency and tidal volume in anesthetic dogs at the dosage of 857.00, 214.29, 42.86 mg/kg (P>0.05). At the dosage of 428.57, 214.29, 42.86 mg/kg, GSPE had no obvious influence on spontaneous activities and coordinated movements in mice (P>0.05). GSPE did not evidently change the number of sleeping animals, the sleep latency and the sleeping duration with subthreshold dose and threshold dose of pentobarbital sodium (P>0.05). Conclusion GSPE has no evident adverse effects on central nervous system, cardiovascular system and respiratory system in animals.