Phenotypic characteristics and differentiation potential of gingival mesenchymal stem cells in hyperglycemia ­ an ex vivo exploratory study / Características fenotípicas y potencial de diferenciación de las células madre mesenquimales gingivales en la hiperglucemia: un estudio exploratorio ex vivo

Background: The therapeutic use of gingival mesenchymal stem cells (GMSCs) as autologous cells may pose the challenge of alterations inflicted by the hyperglycemic environment. Objective: This study aims to assess the effects of hyperglycemia on the characteristics of GMSCs in diabetics. Materials and Methods: 10 patients who consented and fulfilled the criteria for inclusion and exclusion were recruited and categorized as test (HbA1c > 6.5) and control (HbA1c < 6.0). Gingival explants were obtained from gingival collar of teeth, washed, digested and cultured. The cells were subjected to microscopic observation to assess phenotype characteristics, and flow cytometry and qRT-PCR to assess differentiation potential. Stem cell markers CD90, CD73, CD105, CD34, CD45, HLA DR & HLA ABC, osteogenic differentiation markers RUNX2 & OCN, adipogenic differentiation markers PPARG2 & FABP4 and chondrogenic differentiation markers SOX9 & AGCN were evaluated. Results: Microscopic appearance of spindle shaped cells was found to be comparable in both groups. Flow cytometry results demonstrated comparable expressions with both groups, samples being positive for CD90, CD73, CD105, HLA ABC and negative for CD34, CD45 & HLA DR. There were variations in the expression of markers when assessed for differentiation potentials. Conclusions: The hyperglycemic environment did not manifest any changes in the phenotypic characteristics of GMSCs among diabetics. However, the expression of certain differentiation markers was significantly altered in the diabetic test population included. Further research is being conducted to understand the GMSCs in a hyperglycemic environment with an aim to develop strategies to optimize its clinical implications. Keywords: Gingiva; Mesenchymal stem cells; Diabetes mellitus; Cell Differentiation; Hyperglycemia; Flow cytometry.

Antededentes: El uso terapéutico de células madre mesenquimales gingivales(GMSC) como células autólogas puede plantear el desafío de las alteraciones infligidas por el entorno hiperglucémico. Objetivo: Este estudio tiene como objetivo evaluar los efectos de la hiperglucemia sobre las características de las GMSC en diabéticos. Materiales y Métodos: Se reclutaron y categorizaron 10 pacientes que dieron su consentimiento y cumplieron los criterios de inclusión y exclusión como prueba (HbA1c > 6,5) y control (HbA1c < 6,0). Los explantes gingivales se obtuvieron del cuello gingival de los dientes, se lavaron, digirieron y cultivaron. Las células se sometieron a observación microscópica para evaluar las características fenotípicas y a citometría de flujo y qRT-PCR para evaluar el potencial de diferenciación. Se evaluaron los marcadores de células madre CD90, CD73, CD105, CD34, CD45, HLA DR y HLA ABC, marcadores de diferenciación osteogénica RUNX2 y OCN, marcadores de diferenciación adipogénica PPARG2 y FABP4 y marcadores de diferenciación condrogénica SOX9 y AGCN. Resultados: Se encontró que la apariencia microscópica de las células fusiformes era comparable en ambos grupos. Los resultados de la citometría de flujo demostraron expresiones comparables en ambos grupos, siendo las muestras positivas para CD90, CD73, CD105, HLA ABC y negativas para CD34, CD45 y HLA DR. Hubo variaciones en la expresión de los marcadores cuando se evaluaron los potenciales de diferenciación. Conclusiones: El entorno hiperglucémico no manifestó ningún cambio en las características fenotípicas de las GMSC entre los diabéticos. Sin embargo, la expresión de ciertos marcadores de diferenciación se alteró significativamente en la población de prueba de diabetes incluida. Se están realizando más investigaciones para comprender las GMSC en un entorno hiperglucémico con el objetivo de desarrollar estrategias para optimizar sus implicaciones clínicas.

Ubiquitin-specific protease 42 regulates osteogenic differentiation of human adipose-derived stem cells / 北京大学学报(医学版)

Objective:To explore the effect of ubiquitin-specific protease 42(USP42)on osteogenic differentiation of human adipose-derived stem cells(hASCs)in vivo and in vitro.Methods:A combina-tion of experiments was carried out with genetic depletion of USP42 using a lentiviral strategy.Alkaline phosphatase(ALP)staining and quantification,alizarin red S(ARS)staining and quantification were used to determine the osteogenic differentiation ability of hASCs under osteogenic induction between the experimental group(knockdown group and overexpression group)and the control group.Quantitative re-verse transcription PCR(qRT-PCR)was used to detect the expression levels of osteogenesis related genes in the experimental group and control group,and Western blotting was used to detect the expression levels of osteogenesis related proteins in the experimental group and control group.Nude mice ectopic im-plantation experiment was used to evaluate the effect of USP42 on the osteogenic differentiation of hASCs in vivo.Results:The mRNA and protein expressions of USP42 in knockdown group were significantly lower than those in control group,and those in overexpression group were significantly higher than those in control group.After 7 days of osteogenic induction,the ALP activity in the knockdown group was sig-nificantly higher than that in the control group,and ALP activity in overexpression group was significantly lower than that in control group.After 14 days of osteogenic induction,ARS staining was significantly deeper in the knockdown group than in the control group,and significantly lighter in overexpression group than in the control group.The results of qRT-PCR showed that the mRNA expression levels of ALP,os-terix(OSX)and collagen type Ⅰ(COL Ⅰ)in the knockdown group were significantly higher than those in the control group after 14 days of osteogenic induction,and those in overexpression group were signifi-cantly lower than those in control group.The results of Western blotting showed that the expression levels of runt-related transcription factor 2(RUNX2),OSX and COL Ⅰ in the knockout group were significant-ly higher than those in the control group at 14 days after osteogenic induction,while the expression levels of RUNX2,OSX and COL Ⅰ in the overexpression group were significantly lower than those in the control group.Hematoxylin-eosin staining of subcutaneous grafts in nude mice showed that the percentage of osteoid area in the knockdown group was significantly higher than that in the control group.Conclusion:Knockdown of USP42 can significantly promote the osteogenic differentiation of hASCs in vitro and in vi-vo,and overexpression of USP42 significantly inhibits in vivo osteogenic differentiation of hASCs,and USP42 can provide a potential therapeutic target for bone tissue engineering.

Developmental toxicity of Cry1Ab protein in the embryonic stem-cell model / 北京大学学报(医学版)

Objective:To evaluate the developmental toxicity of Cry1Ab protein by studying its effects on cell proliferation and differentiation ability using a developmental toxicity assessment model based on embryonic stem-cell.Methods:Cry1Ab protein was tested in seven dose groups(31.25,62.50,125.00,250.00,320.00,1 000.00,and 2 000.00 μg/L)on mouse embryonic stem cells D3(ES-D3)and 3T3 mouse fibroblast cells,with 5-fluorouracil(5-FU)used as the positive control and phos-phate buffer saline(PBS)as the solvent control.Cell viability was detected by CCK-8 assay to calculate the 50％inhibitory concentration(IC50)of the test substance for different cells.Additionally,Cry1 Ab protein was tested in five dose groups(125.00,250.00,320.00,1 000.00,and 2 000.00 μg/L)on ES-D3 cells,with PBS as the solvent control and 5-FU used for model validation.After cell treatment,cardiac differentiation was induced using the embryonic bodies(EBs)culture method.The growth of EBs was observed under a microscope,and their diameters on the third and fifth days were measured.The proportion of EBs differentiating into beating cardiomyocytes was recorded,and the 50％inhibition con-centration of differentiation(ID50)was calculated.Based on a developmental toxicity discrimination func-tion,the developmental toxicity of the test substances was classified.Furthermore,at the end of the cul-ture period,mRNA expression levels of cardiac differentiation-related markers(Oct3/4,GATAA-4,Nkx2.5,and β-MHC)were quantitatively detected using real-time quantitative polymerase chain reaction(qPCR)in the collected EBs samples.Results:The IC50 of 5-FU was determined as 46.37 μg/L in 3T3 cells and 32.67 μg/L in ES-D3 cells,while the ID50 in ES-D3 cells was 21.28 μg/L.According to the discrimination function results,5-FU was classified as a strong embryotoxic substance.There were no sta-tistically significant differences in cell viability between different concentrations of Cry 1 Ab protein treat-ment groups and the control group in both 3T3 cells and ES-D3 cells(P＞0.05).Moreover,there were no statistically significant differences in the diameter of EBs on the third and fifth days,as well as their morphology,between the Cry1Ab protein treatment groups and the control group(P＞0.05).The cardi-ac differentiation rate showed no statistically significant differences between different concentrations of Cry1Ab protein treatment groups and the control group(P＞0.05).5-FU significantly reduced the mRNA expression levels of β-MHC,Nkx2.5,and GATA-4(P＜0.05),showing a dose-dependent trend(P＜0.05),while the mRNA expression levels of the pluripotency-associated marker Oct3/4 exhibited an increasing trend(P＜0.05).However,there were no statistically significant differences in the mRNA expression levels of mature cardiac marker β-MHC,early cardiac differentiation marker Nkx2.5 and GATA-4,and pluripotency-associated marker Oct3/4 between the Cry1Ab protein treatment groups and the control group(P＞0.05).Conclusion:No developmental toxicity of Cry1Ab protein at concen-trations ranging from 31.25 to 2 000.00 μg/L was observed in this experimental model.

Differentiation therapies in human cancers / 国际肿瘤学杂志

Cancer phenotypic plasticity includes dedifferentiation, blocked differentiation and trans- differentiation, and differentiation therapy targeting tumor cell plasticity is becoming a new therapeutic model for human cancers. The application of inducing differentiation, initiating differentiation and regulating differentiation in tumor differentiation therapy will promote the directed differentiation of tumor cells into mature cells and the remodeling of phenotypes, thus to achieve the purpose of cancer treatment.

Effects of micro-electric field on proliferation and osteogenic differentiation of human umbilical cord mesenchymal stem cells / 中国组织工程研究

BACKGROUND:Electrical stimulation is a physical method that can be used to induce various cellular activities such as cell proliferation,differentiation,and apoptosis.The induction of osteogenic differentiation of stem cells will be beneficial in the field of bone regeneration. OBJECTIVE:To observe whether micro-current field can promote the proliferation and osteogenic differentiation of human umbilical cord mesenchymal stem cells. METHODS:The fresh human umbilical cord tissue was cut to obtain umbilical cord mesenchymal stem cells,which were inoculated into a 6-well plate after cell culture and passage to the third generation.After 24 hours,the cells were cultured under a stimulation of 0,50,and 100 mV/mm micro-electric field,at a frequency of 1 hour per day for 3 continuous days.The growth and morphological changes of human umbilical cord mesenchymal stem cells were observed by a microscope.The cell proliferation was detected by CCK-8 assay and EdU staining.Alizarin red staining was used to detect the osteogenic differentiation ability of cells.Western blot assay was used to determine the expression of ERK signal pathway proteins. RESULTS AND CONCLUSION:(1)The optical density value and the number of proliferating cells in 50 and 100 mV/mm groups were significantly higher than those of the unstimulated group(P<0.05).(2)Human umbilical cord mesenchymal stem cells could be induced to differentiate into osteocytes before and after micro-electric field stimulation,but the differentiation rate of 50 and 100 mV/mm groups was faster than that of unstimulated groups.(3)The protein expression of p-ERK1/2 in the 50 and 100 mV/mm groups was higher than that in the unstimulated group,and significant difference was detected between the 100 mV/mm group and the unstimulated group(P<0.05).(4)Micro-electric field can promote the proliferation of human umbilical cord mesenchymal stem cells,and the mechanism may be achieved by promoting the phosphorylation of ERK.

Factors affecting differentiation of tendon stem/progenitor cells / 中国组织工程研究

BACKGROUND:Tendinopathy is a musculoskeletal disorder characterized by pain and decreased mobility,with pathological changes of disturbed collagen and hyperplasia of the vasculature.Tendinopathy tends to occur in athletes,physical workers,and the elderly.One of the mechanisms of tendinopathy is the"failed healing response",and part of what causes the failed healing response is the erroneous differentiation of tendon stem/progenitor cells. OBJECTIVE:By reviewing the relevant literature,we introduce the characteristics of tendon stem/progenitor cells,summarize the factors that affect the differentiation of tendon stem/progenitor cells to tendon cells and those that lead to mis-differentiation of tendon stem/progenitor cells(differentiation to adipocytes,osteocytes and chondrocytes),and also describe the limitations of tendon stem/progenitor cells in clinical applications. METHODS:PubMed and Web of Science databases were searched for the terms"tendon stem/progenitor cells,tendinopathy,tendon injury,differentiation".The relevant literature was screened by reading and 109 articles were included for the analysis of the results. RESULTS AND CONCLUSION:(1)Tendon stem/progenitor cells are a type of stem cells that can spontaneously differentiate into tendons and have the ability to self-renew,clone,and multi-differentiate.Various external conditions acting on tendon stem/progenitor cells can lead them to differentiate in diverse directions.The specific factors that regulate the fate of tendon stem/progenitor cells are not known with certainty.When stem cell renewal and differentiation in tendons becomes abnormal,it can lead to failure of tendon healing and consequently to tendinopathy.(2)Aging,changes in extracellular matrix composition,excessive mechanical stimulation,prostaglandin E2 and interleukin-6 as well as interleukin-10 and some systemic diseases may be important in regulating the mis-differentiation of tendon stem/progenitor cells.(3)Possible favorable factors that promote the differentiation of tendon stem/progenitor cells to tenocytes are:some growth factors and cytokines,moderate mechanical stimulation and topography of the extracellular matrix,low oxygen tension,drugs,and several transcriptional genes and proteins.(4)The most desirable therapeutic tools are the regulation of endogenous tendon stem/progenitor cells or the stimulation of endogenous tendon stem/progenitor cell proliferation and differentiation by exogenous tendon stem/progenitor cells.(5)Understanding the factors that regulate mis-differentiation of tendon stem/progenitor cells may provide insight into the pathogenesis of tendinopathy and identify therapeutic targets.Elaborating on the induction of tendon stem/progenitor cell differentiation into tendons could facilitate their use in tissue engineering.

Biological characteristics of induction-produced polyploid tumor giant cells in ovarian cancer cell line SKOV3 / 肿瘤研究与临床

Objective:To investigate the morphological and biological characteristics of polyploid tumor giant cells (PGCC) produced by ovarian cancer cell line SKOV3 induced by CoCl 2. Methods:Human ovarian cancer cell line SKOV3 was induced-cultured with 300 μmol/L CoCl 2 in the simulated hypoxic environment for 36 h, the live cells continued to be conventionally cultured and passaged, and the cells collected 20 days later were PGCC group; SKOV3 cell line cultured conventionally was the control group. The formation process and morphological characteristics of PGCC were observed by inverted microscope. The expression of tumor stem cell markers OCT4 and CD117 were detected by immunocytochemistry. The adipogenic differentiation and osteogenic differentiation potential of PGCC were detected by using human bone marrow mesenchymal stem cell adipogenic differentiation assay kit and human bone marrow mesenchymal stem cell osteogenic differentiation assay kit.The cell migration ability of PGCC was detected by scratch assay. PGCC group and control group SKOV3 cells were treated with 1 μmol/L paclitaxel, and the cell morphology of the two groups was observed by microscope at 0, 24 and 48 h to detect the resistance of PGCC to chemotherapy drugs. Results:A small amount of PGCC was observed in SKOV3 cell line cultured in conventional medium under the microscope. CoCl 2 can induce SKOV3 cells to form PGCC, which was nearly round in shape and lacked branching. Its volume was 3 times or more than that of SKOV3 cells, and the nuclei were usually megakaryons or multinucleates, PGCC can produce daughter cells by budding. Immunocytochemical staining showed that OCT4 was positive in some PGCC, but no CD117 was positive. Neither OCT4 nor CD117 was expressed in SKOV3 cells. When cultured with lipid-induced differentiation medium of human bone marrow mesenchymal stem cells, the formation of large vacuoles in the cytoplasm of PGCC was observed at the 3rd cycle, and orange-red, round-like lipid droplets were shown by oil red O staining. Human bone marrow mesenchymal stem cells were cultured in osteogenic induction culture medium for 20 days, and alizarin red staining showed that calcium nodules formed significantly in cells of PGCC group compared with the control group. The cell scratch assay results showed that the migration rates of PGCC cultured in serum-free medium [(59±1)%, (66±3)%] were higher than those of the control group [(11±3)%, (14±5)%] at 24 and 48 h after scratch ( t values were 32.20 and 19.55, both P < 0.001). The migration rates of PGCC cultured in 10% serum medium [(92±3)%, (100±0)%] were higher than those of the control group [(20±6)%, (59±9)%] ( t values were 16.19 and 8.00, both P < 0.001). After 1 μmol/L paclitaxel treatment for 48 h, most of the cells in the PGCC group still survived, while most of the SKOV3 cells in the control group died. Conclusions:PGCC produces daughter cells by budding. PGCC has the characteristics of tumor stem cells: it expresses tumor stem cell markers and has the potential for multidirectional differentiation and strong resistance to chemotherapy drugs.

Effect of ethyl acetate extract from Mimosa pudica root on acute myeloid leukemia in mice / 中国药房

OBJECTIVE To study the inhibitory effect of ethyl acetate extract from Mimosa pudica root （ethyl acetate extract for short） on acute myeloid leukemia in mice. METHODS Different concentrations of ethyl acetate extract （0.062 5， 0.125， 0.25， 0.5 mg/mL） were used to treat acute myelomonocytic leukemia cell lines WEHI-3， and their effects on cell viability were investigated. Fifty BALB/C mice were randomly divided into blank control group， model group， positive control group （5- fluorouracil， 13 mg/kg）， and ethyl acetate extract low-dose and high-dose groups （50， 200 mg/kg）， with 10 mice in each group. Except for the blank control group， the leukemia model was constructed by intraperitoneal injection of WEHI-3 cells in other groups， and from the second day of modeling， corresponding drugs/water were orally administered once a day for 14 consecutive days. After the last administration， the liver and spleen indexes of mice were measured， and liver tissue pathological morphology observation， hematological analysis， and white blood cell differentiation detection were performed； the levels of cytokine [interleukin-2 （IL-2）， IL-3， interferon-γ （IFN-γ）， tumor necrosis factor-α （TNF-α）] in serum were determined； the levels of leukocyte surface markers [cluster of differentiation 3 （CD3）， CD19， CD11b， CD107b （Mac-3）] in whole blood were all detected. RESULTS After treated with 0.062 5-0.5 mg/mL ethyl acetate， the inhibition rate of cell proliferation were increased significantly （P＜0.05）. After intervention with high-dose ethyl acetate， the liver and spleen index， serum level of TNF-α， the levels of CD11b and Mac-3 in blood were significantly reduced （P＜0.05）， while serum levels of IL-2， IL-3 and IFN-γ， and the levels of CD3 and CD19 in blood were increased significantly （P＜0.05）. Occasional lymphocyte infiltration was present in the liver parenchyma， with almost no infiltration of inflammatory cells； hematology improvement and weakened white blood cell differentiation were found. CONCLUSIONS The ethyl acetate extract of M. pudica root can inhibit the proliferation of WEHI-cells， and improve symptoms in acute myeloid leukemia mice， the mechanism of which may be associated with enhancing the immune function.

Effect of ethyl acetate extract from Mimosa pudica root on acute myeloid leukemia in mice / 中国药房

OBJECTIVE To study the inhibitory effect of ethyl acetate extract from Mimosa pudica root （ethyl acetate extract for short） on acute myeloid leukemia in mice. METHODS Different concentrations of ethyl acetate extract （0.062 5， 0.125， 0.25， 0.5 mg/mL） were used to treat acute myelomonocytic leukemia cell lines WEHI-3， and their effects on cell viability were investigated. Fifty BALB/C mice were randomly divided into blank control group， model group， positive control group （5- fluorouracil， 13 mg/kg）， and ethyl acetate extract low-dose and high-dose groups （50， 200 mg/kg）， with 10 mice in each group. Except for the blank control group， the leukemia model was constructed by intraperitoneal injection of WEHI-3 cells in other groups， and from the second day of modeling， corresponding drugs/water were orally administered once a day for 14 consecutive days. After the last administration， the liver and spleen indexes of mice were measured， and liver tissue pathological morphology observation， hematological analysis， and white blood cell differentiation detection were performed； the levels of cytokine [interleukin-2 （IL-2）， IL-3， interferon-γ （IFN-γ）， tumor necrosis factor-α （TNF-α）] in serum were determined； the levels of leukocyte surface markers [cluster of differentiation 3 （CD3）， CD19， CD11b， CD107b （Mac-3）] in whole blood were all detected. RESULTS After treated with 0.062 5-0.5 mg/mL ethyl acetate， the inhibition rate of cell proliferation were increased significantly （P＜0.05）. After intervention with high-dose ethyl acetate， the liver and spleen index， serum level of TNF-α， the levels of CD11b and Mac-3 in blood were significantly reduced （P＜0.05）， while serum levels of IL-2， IL-3 and IFN-γ， and the levels of CD3 and CD19 in blood were increased significantly （P＜0.05）. Occasional lymphocyte infiltration was present in the liver parenchyma， with almost no infiltration of inflammatory cells； hematology improvement and weakened white blood cell differentiation were found. CONCLUSIONS The ethyl acetate extract of M. pudica root can inhibit the proliferation of WEHI-cells， and improve symptoms in acute myeloid leukemia mice， the mechanism of which may be associated with enhancing the immune function.

Silibinin inhibits lipogenic differentiation of 3T3-F442A adipocytes in murine through inhibition of MEK /ERK pathway and matrix metalloproteinase activity / 安徽医科大学学报

Objective @# To study the effect and mechanism of action of Silibinin on the differentiation of 3T3-F442A preadipocytes in murine．@*Methods @#The effects of 0－400 μmol / L Silibinin on the proliferation of 3T3-F442A adi- pocytes at 24，48 and 72 h were detected by 3-(4，5-dimethylthiazol-2) -2，5-diphenyltetrazolium bromide ( MTT) assay，and the effects of Silibinin on the adipogenesis of 3T3-F442A adipocytes were visualized by Oil Red O stai- ning ; RT-qPCR , Western blot and ELISA assays were used to detect the effects of Silibinin on 3T3-F442A adipo- cyte differentiation-associated transcription factor CCAAT / enhancer binding protein ( C / EBP) α , C / EBP β , per- oxisome proliferator-activated receptor γ cular endothelial growth factor (VEGF) -α and VEGF receptor 2 (VEGFR-2) ，matrix metalloproteinase (MMP) -2 and MMP-9，mitogen-activated protein kinase (MEK) and phosphorylated MEK (p-MEK) ，and extracellular regu- lated protein kinase (ERK) and phosphorylated ERK (p-ERK) expression. (PPARγ) ，adipocyte protein 2 (aP2) ，adipose generation-associated vas@*Results @# MTT assay showed that the cell proliferation rate of 3T3-F442A preadipocytes decreased after 100，200，and 400 μmol /L Silibinin treatment compared with the control group (P＜0. 001) ; Oil Red O staining assay showed that the accumulation of red lipid droplets of the cells in the 160 μmol /L Silibinin assay group significantly decreased ; RT-qPCR assay showed that mRNA expression of C/EBPα , C/EBPβ , PPARγ , aP2，VEGF-α , VEGFR-2，MMP-2，and MMP-9 was down-reg- ulated in 3T3-F442A adipocytes treated with 160 μmol /L Silibinin compared with the control group (P＜0. 001) ; Western blot assay showed that protein expression of C /EBPα , C /EBPβ , PPARγ and aP2 was down-regulated in 3T3-F442A adipocytes treated with 160 μmol /L Silibinin (P＜0. 001) ，and the phosphorylation level of p-MEK/ MEK and p-ERK/ ERK proteins was down-regulated compared with the control group (P ＜0. 001) ; ELISA assay showed that the protein concentrations of MMP-2 and MMP-9 in the cell supernatant were down-regulated (P < 0. 001) in 3T3-F442A adipocytes treated with 160 μmol /L Silibinin．@*Conclusion @#Silibinin inhibited 3T3-F442A adipocyte differentiation and adipogenesis through inhibition of the MEK/ ERK pathway and matrix metalloproteinase activity.

Folic acid treatment regulates C2C12 myoblast diferentiation via JNK/p38 MAPK signaling pathway / 中国病理生理杂志

AIM:To observe the effect of folic acid(FA)on C2C12 myoblast proliferation and differentia-tion,and to explore its mechanism.METHODS:During the proliferation stage,C2C12 myoblasts were treated with vari-ous concentrations of FA(0,2.5,5,10 and 20 μmol/L).The cell status was observed under a microscope,cell viability was detected using the MTT method,and cell proliferation was assessed using the EdU method.In the differentiation stage,C2C12 cells were divided into control(Ctrl)group(0 μmol/L FA)and FA group(10 μmol/L FA).On day 2 or 4 of differentiation,immunofluorescence staining and Western blot were employed to detect the expression of myoblast differen-tiation-related proteins,myoblast determination protein 1(MyoD),myogenin(MyoG)and myosin heavy chain(MyHC).The myotubule formation in each group was analyzed.On day 4 of differentiation,C2C12 cells were treated with FA for 0,1,3 and 6 h,and the protein levels of p-JNK,JNK,p-p38 MAPK and p38 MAPK at each time point were detected by Western blot.Additionally,C2C12 cells after 4-day differentiation were divided into Ctrl group,FA group,FA+ SP600125(specific inhibitor of JNK)group,and FA+SB203580(specific inhibitor of p38)group.The cells in FA+ SP600125 and FA+SB203580 groups were treated with 10 μmol/L SP600125 or SB203580 for 1 h,followed by treatment with 10 μmol/L FA for 24 h.The cells in FA group were treated with 10 μmol/L FA for 24 h,while the cells in Ctrl group were left untreated.The protein levels of p-JNK,JNK,p-p38 MAPK,p38 MAPK and MyHC were detected by Western blot.RESULTS:(1)Compared with 0 μmol/L FA group,the number of the cells in other concentration groups in-creased,cell viability was raised(P＜0.05 or P＜0.01),and the rate of EdU positive cells increased(P＜0.05).(2)Com-pared with Ctrl group,the expression levels of MyoD,MyoG and MyHC in FA group were increased(P＜0.05),and the myotube fusion index was raised(P＜0.05 or P＜0.01).(3)Compared with 0 h group,the ratios of p-JNK/JNK and p-p38 MAPK/p38 MAPK were elevated after FA treatment for 1,3 and 6 h(P＜0.05 or P＜0.01),and showed a trend of gradual increase with the extension of treatment time.(4)After FA treatment,the ratios of p-JNK/JNK and p-p38 MAPK/p38 MAPK,and the expression of MyHC were elevated(P＜0.01).Treatment with SP600125 decreased the ratio of p-JNK/JNK and the expression of MyHC(P＜0.05),while SB203580 intervention cut down the ratio of p-p38 MAPK/p38 MAPK and the expression of MyHC(P＜0.05 or P＜0.01).CONCLUSION:Folic acid can promote the differentiation of C2C12 myoblasts by activating the JNK/p38 MAPK signaling pathway.

Hypertonic environment regulates cadherin expression and affects em-bryoid body differentiation / 中国病理生理杂志

AIM:Given the uncertain impact of osmotic pressure on embryoid body(EB)differentiation,this study aimed to investigate the effects of increased osmotic pressure on EB differentiation and explore the potential relation-ship between this process and cadherin.METHODS:Polhethylene glycol 300(PEG 300)was used to increase the os-motic pressure of the culture medium used for cultivating EBs under both high osmotic pressure and standard culture condi-tions.The experimental design included a control group,an experimental group(hypertonic group),groups treated with varying concentrations of PEG 300,and an experimental group treated with an inhibitor.Western blot,RT-qPCR,AM/PI staining,CCK-8,and immunocytochemical staining was used to analyze the cell viability and the expression of CDH1 and CDH2 markers of the three germ layers,and pluripotency markers within the EBs.RESULTS:Hypertonicity did not af-fect cell viability.Significant differences were observed in the expression of the cadherin proteins CDH1 and CDH2 in EBs between the experimental and control groups;however,no cleartrend towards an EMT shift was observed.Specifically,CDH2 expression was significantly down-regulated in experimental group,showing a clear correlation with variations in os-motic pressure.Moreover,compared with control group,pluripotency markers in the EBs from experimental group exhibited significantly higher expression levels from the 2nd day to the 5th day.A substantial increase in the expression of mesoder-mal markers was also observed;however,a downward trend was observed for ectodermal markers in experimental group.Intervention using SB431542,which up-regulates CDH2 expression by affecting TGF-β signaling,reversed the expression trend of mesodermal and ectodermal markers in experimental group.CONCLUSION:Elevated osmotic pressure appears to enhance the mesodermal differentiation efficiency in EBs,possibly correlating with CDH1 and CDH2 changes induced by osmotic pressure.Therefore,this study emphasizes the significant role of osmotic pressure in stem cell applications.

Role of Ca2+in electromagnetic field regulation on osteoblast proliferation and differentiation / 中国医学物理学杂志

Objective To explore the effects of electromagnetic field(EMF)on thechange of Ca2+ in osteolbast from the qualitative and quantitative perspectives,and try to identify the role of Ca2+in EMF regulation on osteoblast proliferation and differentiation.Methods A platform was established for generating sine EMF with a frequency of 38.7 Hz and a strength of 1.5 mT.The MC3T3-E1 osteoblasts were randomly divided into control group and experimental group(EMF intervention for 8 h per day).CCK8 was used to detect osteoblast proliferation,ALP staining to detect osteoblast differentiation,and Ca2+fluorescence probes and flow cytometer to detect the Ca2+concentration in osteoblasts.Results CCK8 result showed that EMF intervention for 48,72,96 and 120 h could significantly promote osteoblast proliferation.After 14 days of EMF intervention,the positive expression of ALP was significantly higher in EMF group than in control group.Ca2+fluorescent staining and flow cytometry results revealed that EMF intervention could increase the Ca2+in osteoblasts.Conclusion The EMF-induced upregulation of Ca2+ signal in osteoblasts may be closely related to the promotions of osteoblast proliferation and differentiation by EMF,but which Ca2+-related biosignaling pathways are involved in the EMF promoting osteoblast proliferation and differentiation remains to be further investigated.

Comparison of techniques for corneal epithelium cell culture for the collection of conditioned medium / Comparação das técnicas de cultivo de células epiteliais da córnea para a coleta de meio condicionado

ABSTRACT Purposes: To determine the best protocol in obtaining the higher yield of conditioned culture medium to be used for the bone marrow mesenchymal stem cell differentiation into corneal epithelial cells, five techniques for the primary culture of human corneal epithelial cells were evaluated. Methods: The studied culture techniques of corneal epithelial cells were: explants in culture flasks with and without hydrophilic surface treatment, on amniotic membrane, with enzymatic digestion, and by corneal scraping. The conditioned culture medium collected from these cultures was used to differentiate human bone marrow mesenchymal stem cells into corneal epithelial cells, which were characterized using flow cytometry with pan-cytokeratin and the corneal-specific markers, cytokeratin 3 and cytokeratin 12. Results: The culture technique using flasks with hydrophilic surface treatment resulted in the highest yield of conditioned culture medium. Flasks without surface treatment resulted to a very low success rate. Enzymatic digestion and corneal scraping showed contamination with corneal fibroblasts. The culture on amniotic membranes only allowed the collection of culture medium during the 1st cell confluence. The effectiveness of cell differentiation was confirmed by cytometry analysis using the collected conditioned culture medium, as demonstrated by the expressions of cytokeratin 3 (95.3%), cytokeratin 12 (93.4%), and pan-cytokeratin (95.3%). Conclusion: The culture of corneal epithelial cell explants in flasks with hydrophilic surface treatment is the best technique for collecting a higher yield of conditioned culture medium to be used to differentiate mesenchymal stem cells.

RESUMO Objetivos: Foram estudadas cinco técnicas de cultivo primário de células epiteliais de córnea humana para se determinar o melhor protocolo para a obtenção do maior rendimento de meio de cultivo condicionado para ser utilizado na diferenciação de células tronco mesenquimais para células epiteliais de córnea. Métodos: As técnicas de cultivo estudadas foram: explantes em frascos de cultivo com e sem tratamento hidrofílico de superfície, sobre membrana amniótica, com digestão enzimática e por raspado de córnea. O meio de cultivo condicionado foi coletado e as células tronco mesenquimais induzidas a se diferenciarem em células epiteliais da córnea utilizando o meio de cultivo condicionado. As células foram caracterizadas por citometria de fluxo com pan-citoqueratina e com os marcadores específicos da córnea, citoqueratina 3 e citoqueratina 12. Resultados: A técnica utilizando frascos com o tratamento de superfície apresentou o maior rendimento de meio de cultivo condicionado. Os frascos sem tratamento de superfície levaram a uma taxa de sucesso muito baixa. A digestão enzimática e a raspagem da córnea mostraram contaminação das culturas com fibroblastos de córnea. A cultura sobre membranas amnióticas só permitiu a coleta do meio de cultivo condicionado durante a 1ª confluência celular. A análise de citometria de fluxo confirmou o sucesso da diferenciação celular utilizando o meio de cultivo condicionado coletado, demonstrada pela expressão de citoqueratina 3 (95,3%), citoqueratina 12 (93,4%) e pan-citoqueratina (95,3%). Conclusão: O cultivo de explantes de células tronco mesenquimais em frascos com tratamento hidrofílico de superfície é a melhor técnica para a obtenção de um alto rendimento de meio de cultivo condicionado.

Influence of the addition of nanohydroxyapatite to scaffolds on proliferation and differentiation of human mesenchymal stem cells: a systematic review of in vitro studies

One of the main challenges of tissue engineering in dentistry is to replace bone and dental tissues with strategies or techniques that simulate physiological tissue repair conditions. This systematic review of in vitro studies aimed to evaluate the influence of the addition of nanohydroxyapatite (NHap) to scaffolds on cell proliferation and osteogenic and odontogenic differentiation of human mesenchymal stem cells. In vitro studies on human stem cells that proliferated and differentiated into odontogenic and osteogenic cells in scaffolds containing NHap were included in this study. Searches in PubMed/MEDLINE, Scopus, Web of Science, OpenGrey, ProQuest, and Cochrane Library electronic databases were performed. The total of 333 articles was found across all databases. After reading and analyzing titles and abstracts, 8 articles were selected for full reading and extraction of qualitative data. Results showed that despite the large variability in scaffold composition, NHap-containing scaffolds promoted high rates of cell proliferation, increased alkaline phosphatase (ALP) activity during short culture periods, and induced differentiation, as evidenced by the high expression of genes involved in osteogenesis and odontogenesis. However, further studies with greater standardization regarding NHap concentration, type of scaffolds, and evaluation period are needed to observe possible interference of these criteria in the action of NHap on the proliferation and differentiation of human stem cells.

Teriparatide regulates osteoblast differentiation in high-glucose microenvironment through the cAMP/PKA/CREB signaling pathway / 南方医科大学学报

OBJECTIVE@#To investigate the effect of teriparatide on the differentiation of MC3T3-E1 cells in high-glucose microenvironment and explore the possible mechanism.@*METHODS@#MC3T3-E1 cells cultured in normal glucose or high-glucose (25 mmol/L) medium were treated with 10 nmol/L teriparatide with or without co-treatment with H-89 (a PKA inhibitor). CCK-8 assay was used to detect the changes in cell proliferation, and cAMP content in the cells was determined with ELISA. Alkaline phosphatase (ALP) activity and mineralized nodules in the cells were detected using ALP kit and Alizarin red staining, respectively. The changes in cell morphology were detected by cytoskeleton staining. Real-time PCR was used to detect the mRNA expressions of PKA, CREB, RUNX2 and Osx in the treated cells.@*RESULTS@#The treatments did not result in significant changes in proliferation of MC3T3-E1 cells (P > 0.05). Compared with the cells in routine culture, the cells treated with teriparatide showed significantly increased cAMP levels (P < 0.05) with enhanced ALP activity and increased area of mineralized nodules (P < 0.05). Teriparatide treatment also resulted in more distinct visualization of the cytoskeleton in the cells and obviously up-regulated the mRNA expressions of PKA, CREB, RUNX2 and Osx (P < 0.05). The opposite changes were observed in cells cultured in high glucose. In cells exposed to high glucose, treatment with teriparatide significantly increased cAMP levels (P < 0.05), ALP activity and the area of mineralized nodules (P < 0.05) and enhanced the clarity of the cytoskeleton and mRNA expressions of PKA, CREB, RUNX2 and Osx; the effects of teriparatide was strongly antagonized by co-treatment with H-89 (P < 0.05).@*CONCLUSION@#Teriparatide can promote osteoblast differentiation of MC3T3-E1 cells in high-glucose microenvironment possibly by activating the cAMP/PKA/CREB signaling pathway.

Micro/nano hierarchical structure of titanium surface promotes MC3T3-E1 adhesion proliferation and drug loading potential evaluation / 口腔疾病防治

Objective @# To investigate the effect of micro/nano hierarchical structures on the adhesion and proliferation of MC3T3-E1 cells, evaluate the drug delivery potential of titanium surfaces, and provide a reference for the modification of selected areas of titanium surfaces to enhance drug delivery and slow drug release. @*Methods @# Pure titanium samples (10 mm in diameter and 2.5 mm in thickness) were randomly divided into a polished group (T), anodized group (TO), and micro/nano hierarchical structure group (FTO) according to the surface treatment of the titanium. The T group was polished, the TO group was treated with anodic oxidation technology, and the FTO group was treated by femtosecond laser etching combined with anodic oxidation technology. The three surface morphologies were observed by scanning electron microscopy (SEM), the wettability of the surface was measured by the contact angle, and the surface chemical composition was analyzed by X-ray energy dispersive spectroscopy (EDS). The depth of the FTO structure and the surface roughness were measured by confocal laser scanning microscopy (CLSM). MC3T3-E1 cell adhesion proliferation and differentiation on the surface of each group of samples was assessed by immunofluorescence staining, CCK-8, and semiquantitative analysis of Alizarin staining. A freeze-drying method was applied to load recombinant human bone morphogenetic protein-2 (rhBMP-2), and an enzyme-linked immunosorbent assay (ELISA) was used to assess the drug-loading potential of different surface structures. @* Results@#SEM revealed that the surface of T group titanium plates showed uniform polishing marks in the same direction. The surface of the TO group was a nanoscale honeycomb-like titanium dioxide (TiO2) nanotube structure, and the FTO group formed a regular and ordered micro/nano layered structure. The contact angle of the FTO group was the smallest at 32° ± 1.7°. Its wettability was the best. The average depth of the first-level structure circular pores was 93.6 μm, and the roughness was 1.5-2 μm. The TO and FTO groups contained a high percentage of oxygen, suggesting TiO2 nanotube formation. The FTO group had the most significant surface cell proliferation (P<0.001) and the largest cell adhesion surface area (P<0.05). rhBMP-2 was slowly released for 14 d after loading in the FTO group and promoted extracellular matrix mineralization (P<0.001). @*Conclusion @#Titanium surface microprepared hierarchical structure has the effect of promoting MC3T3-E1 cell adhesion, proliferation, and osteogenic differentiation with drug loading potential, which is a new method of titanium surface treatment.

Effects of Cyclic Strain on Neural Differentiation of Rat Bone Marrow-Derived Mesenchymal Stem Cells / 医用生物力学

Objective To study the mechanical effects of cyclic strain on neural differentiation of rat bone marrow mesenchymal stem cells (rBMSCs). Methods The rBMSCs were subjected to cyclic strain for 24 hours andthen cultured for 5 days. The expression of neural markers and the phosphorylation of relative signaling pathway proteins were evaluated. The stress distribution on cell surface was analyzed by finite element method. The differentially expressed genes induced by strain were identified by RNA sequencing analysis. Results The 0. 5 Hz strain with 5% magnitude could significantly induce higher expression of neural markers and elevated phosphorylation level of extracellular-signal-regulated kinase (ERK), protein kinase B (AKT) and mammalian target of rapamycin ( mTOR). KEGG pathway analysis showed that the focal adhesion and ECM-receptor interaction were significantly enriched under cyclic strain. Conclusions Cyclic strain could change the interaction of cells with the extracellular matrix ( ECM) and enhance the AKT/ mTOR and ERK pathway, finally promote rBMSC neural differentiation. Knowledge about the impact of mechanical stimulation on BMSC neural differentiation is expected to improve the efficiency of stem cell differentiation, shed light on device design for tissue engineering, and promote clinical application of mesenchymal stem cells in neural issue repair and regeneration.

Cloning, identification and functional analysis of the goat transcription factor c-fos / 生物工程学报

C-fos is a transcription factor that plays an important role in cell proliferation, differentiation and tumor formation. The aim of this study was to clone the goat c-fos gene, clarify its biological characteristics, and further reveal its regulatory role in the differentiation of goat subcutaneous adipocytes. We cloned the c-fos gene from subcutaneous adipose tissue of Jianzhou big-eared goats by reverse transcription-polymerase chain reaction (RT-PCR) and analyzed its biological characteristics. Using real-time quantitative PCR (qPCR), we detected the expression of c-fos gene in the heart, liver, spleen, lung, kidney, subcutaneous fat, longissimus dorsi and subcutaneous adipocytes of goat upon induced differentiation for 0 h to 120 h. The goat overexpression vector pEGFP-c-fos was constructed and transfected into the subcutaneous preadipocytes for induced differentiation. The morphological changes of lipid droplet accumulation were observed by oil red O staining and bodipy staining. Furthermore, qPCR was used to test the relative mRNA level of the c-fos overexpression on adipogenic differentiation marker genes. The results showed that the cloned goat c-fos gene was 1 477 bp in length, in which the coding sequence was 1 143 bp, encoding a protein of 380 amino acids. Protein structure analysis showed that goat FOS protein has a basic leucine zipper structure, and subcellular localization prediction suggested that it was mainly distributed in the nucleus. The relative expression level of c-fos was higher in the subcutaneous adipose tissue of goats (P < 0.05), and the expression level of c-fos was significantly increased upon induced differentiation of subcutaneous preadipocyte for 48 h (P < 0.01). Overexpression of c-fos significantly inhibited the lipid droplets formation in goat subcutaneous adipocytes, significantly decreased the relative expression levels of the AP2 and C/EBPβ lipogenic marker genes (P < 0.01). Moreover, AP2 and C/EBPβ promoter are predicted to have multiple binding sites. In conclusion, the results indicated that c-fos gene was a negative regulatory factor of subcutaneous adipocyte differentiation in goats, and it might regulate the expression of AP2 and C/EBPβ gene expression.

Effects of Zuogui Pill on osteoclast activity and expression of miR-133b-3p/RhoA in postmenopausal osteoporosis rats / 国际中医中药杂志

Objective:To study the effects of Zuogui Pills on the expressions of miR-133b-3p and RhoA in osteoclasts of postmenopausal osteoporosis rats; To discuss its potential mechanism.Methods:SD female rats were randomly divided into normal group, model group, sham-operation group, and Zuogui Pills group using a random number table method, with 6 rats in each group. The model group and Zuogui Pills group were treated with oophorectomy to construct a rat model of osteoporosis. Zuogui Pills group was orally administered with Zuogui Pills decoction at a concentration of 10 g/kg for 12 consecutive weeks. Colorimetric method was used to measure the serum calcium and phosphorus levels of rats, and ELISA method was used to detect ALP levels. Bone density meter was used to measure the bone density of the femurs of rats in each group. The osteoclast of each group were cultured, and the expressions of RANKL and RUNX2 protein were detected by Western blot. MiRNA sequencing and differential expression analysis were performed on bone tissues of rats. Osteoclasts were treated with miR-133b-3p mimic and its negative control. The cell proliferation activity of osteoclasts was detected by cell counting kit-8 (CCK-8). The osteoclast differentiation activity was detected by the tartrate-resistant acid phosphatase staining. The dual-luciferase reporter assay was used to detect the relationship between miR-133b-3p and RhoA. The "rescue" experiment of miR-133b-3p mimic and RhoA co-expression were used to study the molecular regulatory mechanism of Zuogui Pills on osteoclast activity.Results:Compared with the model group, the bone mineral density of Zuogui Pills group significantly increased ( P<0.05, P<0.01), the levels of calcium and phosphorus in serum increased, the level of alkaline phosphatase ALP decreased ( P<0.05), the expression of RANKL protein decreased, and the expression of RUNX2 protein increased. Sequencing results showed that rno-miR-133b-3p was down-regulated in osteoclasts of postmenopausa osteoporosis rats treated with Zuogui Pills with the maximum difference ( P<0.01). Q-PCR results showed that the expression of miR-133b-3p in osteoclasts of Zuogui Pills group was significantly lower than that of the model group. The upregulation of miR-133b-3p could significantly promote the cell proliferation and differentiation of osteoclasts. RhoA overexpression could reverse the excessive proliferation and differentiation of osteoclasts caused by miR-133b-3p overexpression. Conclusions:RhoA is the target gene regulated by miR-133b-3p. Zuogui Pills can inhibit the activity of osteoclasts by regulating miR-133b-3p/RhoA axis, relieving the symptoms of osteoporosis.