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.

BACKGROUND:Adipose-derived stem cells have anti-aging effects,but whether adipose-derived stem cells from donors of different ages are different needs further study. OBJECTIVE:To compare the biological properties of adipose-derived stem cells in old and young mice. METHODS:Adipose-derived stem cells were extracted from adipose tissue of C57BL mice aged 8 and 14 weeks,respectively.The differences of cell cycle,apoptosis,and proliferation of adipose-derived stem cells in old and young mice were compared.The expression levels of aging-related P21 and P27 genes and proteins of adipose-derived stem cells in old and young mice were detected by quantitative PCR and western blot assay. RESULTS AND CONCLUSION:Compared with old mouse adipose-derived stem cells,young mouse adipose-derived stem cells were more active,more regular in morphology,less apoptosis,faster proliferation,and lower in expression of age-related P21 and P27 genes and proteins.It has been proven that adipose-derived stem cells from young mice have better anti-aging effects.

BACKGROUND:As an emerging treatment method,stem cell therapy is expected to improve the ovarian environment,delays the aging of ovarian granulosa cells,and brings new hope to older pregnant women.OBJECTIVE:To review the mechanism and research progress of stem cells against ovarian granulosa cell senescence.METHODS:CNKI and PubMed databases were retrieved for articles on stem cell therapy for ovarian granulosa cell senescence.Chinese and English search terms were"stem cells,ovary granulosa cells,aging."Finally,67 articles were included for analysis.RESULTS AND CONCLUSION:(1)This review summarizes five mechanisms of ovarian granulosa cell senescence:DNA damage and decreased repair capacity,oxidative stress,impaired mitochondrial function,inflammatory response,and changes in hormone levels.(2)This article summarizes five main mechanisms of stem cells in the treatment of ovarian granulosa cell senescence:promoting proliferation and inhibiting apoptosis,differentiation potential and regeneration ability,secreting factors,anti-oxidation,anti-inflammatory response,and immune regulation.(3)At present,there are various types of stem cells that can cooperate to treat ovarian granulosa cell senescence through a variety of ways,and stem cell therapy has broad prospects in restoring female fertility.

BACKGROUND:With the increase of age,the function of bone marrow-derived mesenchymal stem cells is gradually reduced,and delaying the aging of bone marrow-derived mesenchymal stem cells itself has become an important topic.OBJECTIVE:To explore ways to delay the aging of bone marrow-derived mesenchymal stem cells by changing the expression of telomerase Cajal body protein 1(TCAB1)gene.METHODS:Mouse bone marrow-derived mesenchymal stem cells were cultured by cell adhesion method.TCAB1 gene in bone marrow-derived mesenchymal stem cells was overexpressed and interfered by recombinant lentivirus technique.The expression of aging related genes P16,P21,P53,and P27 was detected by qPCR.The relative length of telomeres was detected by qPCR.The expression of aging proteins P16,P21,P53,and P27 was detected by western blot assay.Cell proliferation was detected by CCK-8 assay.Annexin V-PE/7-AAD apoptosis kit was used to detect the degree of cell apoptosis.RESULTS AND CONCLUSION:Bone marrow-derived mesenchymal stem cell lines overexpressing TCAB1 gene had decreased expression of senescence related genes and proteins,increased Telomere relative length,stronger cell proliferation,less apoptosis,and a youthful state.The expression of age-related genes and proteins in bone marrow mesenchymal stem cells interfering with TCAB1 gene increased,and the relative telomere length decreased;cell proliferation ability was weak;cell apoptosis was more,and cells showed senescence.These results indicate that increasing the expression of TCAB1 in an appropriate range can delay the rate of cell senescence.

BACKGROUND:As an emerging treatment method,stem cell therapy is expected to improve the ovarian environment,delays the aging of ovarian granulosa cells,and brings new hope to older pregnant women.OBJECTIVE:To review the mechanism and research progress of stem cells against ovarian granulosa cell senescence.METHODS:CNKI and PubMed databases were retrieved for articles on stem cell therapy for ovarian granulosa cell senescence.Chinese and English search terms were"stem cells,ovary granulosa cells,aging."Finally,67 articles were included for analysis.RESULTS AND CONCLUSION:(1)This review summarizes five mechanisms of ovarian granulosa cell senescence:DNA damage and decreased repair capacity,oxidative stress,impaired mitochondrial function,inflammatory response,and changes in hormone levels.(2)This article summarizes five main mechanisms of stem cells in the treatment of ovarian granulosa cell senescence:promoting proliferation and inhibiting apoptosis,differentiation potential and regeneration ability,secreting factors,anti-oxidation,anti-inflammatory response,and immune regulation.(3)At present,there are various types of stem cells that can cooperate to treat ovarian granulosa cell senescence through a variety of ways,and stem cell therapy has broad prospects in restoring female fertility.

BACKGROUND:With the increase of age,the function of bone marrow-derived mesenchymal stem cells is gradually reduced,and delaying the aging of bone marrow-derived mesenchymal stem cells itself has become an important topic.OBJECTIVE:To explore ways to delay the aging of bone marrow-derived mesenchymal stem cells by changing the expression of telomerase Cajal body protein 1(TCAB1)gene.METHODS:Mouse bone marrow-derived mesenchymal stem cells were cultured by cell adhesion method.TCAB1 gene in bone marrow-derived mesenchymal stem cells was overexpressed and interfered by recombinant lentivirus technique.The expression of aging related genes P16,P21,P53,and P27 was detected by qPCR.The relative length of telomeres was detected by qPCR.The expression of aging proteins P16,P21,P53,and P27 was detected by western blot assay.Cell proliferation was detected by CCK-8 assay.Annexin V-PE/7-AAD apoptosis kit was used to detect the degree of cell apoptosis.RESULTS AND CONCLUSION:Bone marrow-derived mesenchymal stem cell lines overexpressing TCAB1 gene had decreased expression of senescence related genes and proteins,increased Telomere relative length,stronger cell proliferation,less apoptosis,and a youthful state.The expression of age-related genes and proteins in bone marrow mesenchymal stem cells interfering with TCAB1 gene increased,and the relative telomere length decreased;cell proliferation ability was weak;cell apoptosis was more,and cells showed senescence.These results indicate that increasing the expression of TCAB1 in an appropriate range can delay the rate of cell senescence.

Ten novel podophyllotoxin derivatives (IIIa-IIIi and IV) were synthesized by three-step reactions using podophyllotoxin and N-benzyloxycarbonyl glycine-L-proline as raw material. The structures of the target compounds were confirmed by 1H NMR, 13C NMR and MS. MTT method was used to test anti-tumor activity of the target compounds on HepG2, THP-1, HeLa and MCF-7 cells. The results showed that all the target compounds had inhibitory activity against HepG2, THP-1, HeLa and MCF-7 cells, and the inhibitory activity of IIIa on HepG2 cells was the most prominent with an IC50 value of 0.58 nmol/L. The binding mode of compound IIIa and FAPα was studied by molecular docking. Compound IIIa could bind to multiple sites of FAPα enzyme.

BACKGROUND: Systemic lupus erythematosus is an autoimmune disease with unknown causes. To establish a tree shrew model of systemic lupus erythematosus is helpful to understand its pathogenesis and provide evidence for stem cell transplantation in the treatment of autoimmune diseases. OBJECTIVE: To establish a tree shrew model of systemic lupus erythematosus and to assess the therapeutic effect of umbilical cord mesenchymal stem cell transplantation. METHODS: Tree shrews were grouped and intraperitoneally injected pristane, lipopolysaccharide, and their combination. At 3 weeks after injection, 12 tree shrew models were divided into treatment group and model control group (n=6 per group). An additional 6 models were selected as a normal control group. In the treatment group, each tree shrew was injected with 1×106 DiR-labeled umbilical cord mesenchymal stem cells through caudal vein. Two weeks later, the heart, liver, spleen, lung and kidney of tree shrews were taken for pathological sections. The sections received hematoxylin-eosin staining, kidney Masson staining and immune complex detection. Simultaneously, the heart, liver, spleen, lung and kidney of the three groups of tree shrews were taken for in vitro imaging. RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining showed pathological changes of the heart, liver, spleen, lung and kidney in the model control group; and there were a lot of immune complex deposits in renal tissue in the model control group. The pathological changes in the treatment group improved, and the structure recovered to close to the normal control group. (2) In vitro imaging showed that DiR-labeled cells were mainly distributed in the lung, liver and spleen of the tree shrews in the treatment group. The fluorescence intensity of tree shrews in the treatment group was significantly higher than that in the normal control group and model control group (P < 0.05). (3) Results demonstrated that intraperitoneal injection of pristane and lipopolysaccharide is the best method to induce pathological changes of systemic lupus erythematosus in tree shrews. The pathological changes after treatment with umbilical cord mesenchymal stem cells have improved, indicating that umbilical cord mesenchymal stem cells have certain treatment effects on tree shrew models of systemic lupus erythematosus.

BACKGROUND: Current treatments for metabolic syndrome are comprehensive treatments with drugs, aiming to improve patient’s life. Patients are required to have a high compliance to follow-up and have developed various adverse reactions. Therefore, there is no treatment to fundamentally delay the development of metabolic syndrome. OBJECTIVE: To establish a tree shrew model of metabolic syndrome and evaluation techniques, and to explore the therapeutic effect of umbilical cord mesenchymal stem cells in the tree shrew model, providing theoretical basis and reference method for clinical application of stem cell transplantation in metabolic syndromes. METHODS: Umbilical cord mesenchymal stem cells of tree shrews were obtained by adherent culture method, and met the biological characteristics of umbilical cord mesenchymal stem cells. The dark red fluorescent iodide DIR was used to label tree umbilical cord mesenchymal stem cells. Thirty-two tree shrews were fed high-sugar, high-cholesterol, high-salt diet and syrup diet, and injected streptozotocin to make metabolic syndrome models. Animal models were randomly divided into model control group (n=10) and cell treatment group (n=22). In the cell treatment group, the umbilical cord mesenchymal stem cells labeled in vitro were injected into the tail vein, and the model group was injected an equal volume of physiological saline in the meanwhile. Blood biochemical indicators, glucose tolerance, insulin resistance index and arterial blood pressure were measured after transplantation. RESULTS AND CONCLUSION: The tree shrew model of metabolic syndrome was successfully constructed, showing obvious insulin resistance, hyperglycemia, lipid metabolism disorder, and hypertension, which met the diagnostic criteria of metabolic syndrome. Umbilical cord mesenchymal stem cells transplantation could significantly reduce the blood glucose and blood lipid levels, improve insulin resistance and regulate insulin secretion in the tree shrew model of metabolic syndrome. Transplanted umbilical cord mesenchymal stem cells could be homing to the liver, kidney and pancreas of the tree shrew model of metabolic syndrome, and produce certain repairing effects.

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.