Recent Progress on Pharmaceutical Properties of Extracellular Vesicles from Mesenchymal Stem Cells--Review / 中国实验血液学杂志

Mesenchymal stem cells (MSCs) have been officially approved in many countries to treat graft-versus-host disease, autoimmune disorders and those associated with tissue regeneration after hematopoietic stem cell transplantation. Studies in recent years have confirmed that MSC acts mainly through paracrine mechanism, in which extracellular vesicles secreted by MSC (MSC-EV) play a central role. MSC-EV has overwhelming advantages over MSC itself in the setting of adverse effects in clinical application, indicating that MSC-EV might take the place of its parent cells to be a potentially therapeutic tool for "cell-free therapy". The pharmaceutical properties of MSC-EV largely depend upon the practical and optimal techniques including large-scale expansion of MSC, the modification of MSC based on the indications and the in vivo dynamic features of MSC-EV, and the methods for preparing and harvesting large amounts of MSC-EV. The recent progresses on the issues above will be briefly reviewed.

System Amplifying NK Cells Using Mononuclear Cell Culture / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To develop an easy method to amplify natural killer (NK) cells by using mononuclear cells in vitro, so as to lay the basis for NK cell therapy.</p><p><b>METHODS</b>Umbilical cord blood from 3 healthy full-term pregnant women was collected, and the peripheral blood mononuclear cells (PBMNC) were harvested by density gradient centrifugation. Each sample of PBMNC was divided into 3 groups: CD16mAb, CD3 mAb and CD16mAb+CD3mAb- groups. The culture flasks were pre-coated with CD16, CD3 or CD3 plus CD16 mAb. The PBMNCs were cultured in serum-free media containing autologous plasma, recombinant human IL-2, IL-15 and IL-21 for 14 days under the same conditions. The total viable cell count was calculated. Flow cytometry was used to determine the ratio of CD56CD3 cells, MTT assay was used to measure the killing rate of NK cells under different effector/target ratio, by using the K562 cells as the target cells.</p><p><b>RESULTS</b>After 14 days of culture, the total cell numbers of CD16mAb, CD3mAb and CD16mAb +CD3mAb groups increased by 45.71±5.54, 87.41±19.77 and 4.88±51.84 times, respectively, and those of CD3mAb group were significantly higher than the other 2 groups (P<0.05). The ratio of CD56CD3 cells before culture was 0.1663±0.0201, which was 0.8167±0.0500, 0.8077±0.0589 and 0.8077±0.0273 after incubation with CD16mAb, CD3mAb and CD16mAb +CD3mAb for 14 days, respectively (P>0.05). MTT test showed that the killing efficiencies were not significantly different among the 3 groups when the effector/target ratios were 1:1, 5:1 and 10:1 (P>0.05).</p><p><b>CONCLUSION</b>By incubation with anti-CD3 monoclonal antibody, IL-2, IL-15 and IL-21, the highly purified NK cells can be obtained from mononucleated cells, thus providing a simple method for NK cell therapy.</p>

Effect of TGF-β1 and IL-10 on the Immunoregulatory Function of Extracellular Vesicles Derived from Mesenchymal Stem Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of immune regulatory molecules TGF-β1 and IL-10 on the immunoregulatory activities of extracellular vesicles(EV) secreted from mesenchymal stem cells (MSCs).@*METHODS@#MSC were isolated from human umbilical cord and expanded, then were treated with TGF-β1 and IL-10 for 72h, and MSC-EVs in supernatants were isolated. The total protein content of all samples was determined by BCA methed. The morphological structure was observed by transmission electron microscopy. The surface markers of MSC-EV were analyzed by flow cytometry. The apoptosis of peripheral blood mononuclear cells(PBMNC) stimulated by ConA and the proportion of CD4CD25/CD127 (Treg) cells were detected by flow cytometry after incubation with MSC-EV for 72 h. The CBA and ELISA kit were used to detect the contents of IL2, IL4, IL6, IL10, IFN-γ, TNF-α, Th17A and TGF-β1 in PBMC supernatants and MSC-EV.@*RESULTS@#All the samples showed that the typical cup-shaped membrane-like structure was observed by transmission electron microscopy, and CD9, CD44, CD63 and CD81 expressed. After TGF-β1 treatment, the MSC-EV displayed the strongest ability to promote PBMNC apoptosis（P<0.01）, and in all the samples the proportion of Treg cells increased. MSC-EV could increase the content of IL-10 in the supernatants of PBMNC culture, the content of TGF-β1 in PBMNC supernatants after MSC treatment with TGF-β1 was lower than that in untreated group(P<0.05). The content of IL-6 in MSC-EV increased significantly after treatment with TGF-β1, and the content of TGF-β1 decreased.@*CONCLUSION@#TGF-β1 alters the immnomodulatory function of MSC-EV and its underlying mechanisms need to be clarified in further investigations.

Clinical Study on Treatment of Juvenile Myelomonocytic Leukemia with Haploidentical-Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To analyze the therapeutic efficacy of haploidentical-hematopoietic stem cell transplantation (hi-HSCT) for patients with juvenile myelomonocytic leukemia (JMML).</p><p><b>METHODS</b>The engraftment of hematopoietic stem cells, incidence of graft versus host disease (GVHD), infection, relapse, and survival of 6 JMML patients received hi-HSCT were retrospectively analyzed.</p><p><b>RESULTS</b>Six (6 males) JMML patients received hi-HSCT from haplo-HLA-matched related donors. The results showed that the hematopoictic stem cells in all 6 patients were grafted successfully. Two cases of JMML died of pulmenary infections, other 4 cases survive without disease. Acute GVHD occurred in 3 patients and chronic GVHD occurred in 1 patients. The overall survival, disease free survival and relapse rates were 66.7%, 66.7%, 0%, respectively.</p><p><b>CONCLUSION</b>The hi-HSCT is an effective method for treatment of patients with JMML, but there also is a serial problems to be resolved.</p>

Mesenchymal Stem Cells Combined with Budesonide, Almeterol and Azithromycin for the Treatment of Bronchiolitis Obliterans Syndrome after Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To evaluate the safety and effectiveness of a novel therapeutic regimen for bronchiolitis obliterans sydrome (BOS) affter hematopoietic stem cell transplantation (HSCT).</p><p><b>METHODS</b>Seven patients who had received HSCT and had been diagnosed as BOS were enrolled in this study. They received weekly intravenous injection of umbilical cord-derived mesenchymal stem cells (MSC) at a dose of 1 × 10(6)/kg for 4 weeks. Budesonide was given orally at a daily dose of 0.25 g, and salmeterol was inhaled at a dose of 4.5 µg for 3 times per day. Methylprednisolone was given at a dose of 1 mg/(kg·d) for 2 weeks when respiratory failure occured. The dose of methylprednisolone was tapered to 0.25 mg/(kg·d) after 4 weeks and was adjusted according to the occurrence and severity of chronic graft-versus-host disease (cGVHD).</p><p><b>RESULTS</b>The therapy was generally safe and no severe acute toxicity was observed. One patient died of heart failure during the treatment, the other 6 patients were alive and the pulmonary function parameters including FEV1, FEV1/FVC, PaO2 and AaDO2 were significantly improved after 6 months as compared with the baseline parameters (P < 0.05).</p><p><b>CONCLUSION</b>MSC combined with budesonide, almeterol and azithromycin has been confirmed to be generally safe and can reduce the dose of glucocorticoid in treatment of BOS after HSCT.</p>

Progesterone Promotes Human Bone Marrow Mesenchymal Stem Cells to Synthesize Fibronectin via ERK Pathway / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate whether the progesterone can promote fibronection (FN) synthesis by human bone marrow mesenchymal stem cells (MSCs) and to explore the potential underlying mechanism.</p><p><b>METHODS</b>The human bone marrow MSCs were cultured in a serum-free medium with progesterone for 72 hours, the MTT test was performed to observe the proliferation status and adhension ability of the treated cells. Western blot was used to detect the content of FN in MSDs with GAPDH as the internal reference, the phosphorylation of ERK1/2, as well as the FN content in MSC treated by PD98059, a specific inhibitor of ERK1/2.</p><p><b>RESULTS</b>The progesterone at a range of certain doses not effect on the proliferation of human bone marrow MSCs. Progesterone (25 µg/L) treatment enhanced the FN expression and adherent ability of marrow MSCs. Progesterone could induce prompt phosphorylation of ERK 1/2 and its promoting effects on FN synthesis was reversed by PD98059.</p><p><b>CONCLUSION</b>The progesterone can promote FN synthesis by human bone marrow MSCs via ERK 1/2 pathway, and it might be used to culture MSCs in serum-free medium.</p>

Silymarin Protects Umbilical Cord-Derived Mesenchymal Stem Cells against Apoptosis Induced by Serum-Deprivation / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the protection of silymarin against the human mesenchymal stem cell (MSC) apoptosis induced by serum deprivation and its underlying mechanism.</p><p><b>METHODS</b>Human umbilical cord MSCs were cultured in the absence of serum, and the silymain of different concentration (1-10 µg/ml) was added into the medium. MTT test was performed to observe the cell proliferation status. After being cultured for 72 hours, the cells were collected, and flow cytometry with Annexin-V-PI double-staining was used to detect the apoptotic cells from the control and silymarin-treated groups. Furthermore, the intracellular contents of BAX and BCL-2 were detected by Western blot for exploring the potential mechanism.</p><p><b>RESULTS</b>The silymarin promoted the proliferation of human UC-MSCs in a dose-dependent manner, reaching its maximal at a dose of 5 µg/ml. Moreover, silymarin could inhibit the serum deprivation-induced apoptosis of MSCs and, the inhibitory rate reached up to 30% when it was added at a concentration of 5 µg/ml. The content of intracellular BAX was obviously elevated after serum-deprivation treatment, and this increase could be blunted by the addition of silymarin. Meanwhile, the content of BCL-2 was not obviously changed.</p><p><b>CONCLUSION</b>The silymarin can stimulate MSC growth and inhibit the apoptosis of MSCs probably by the mitochondria pathway.</p>

Investigation on the internalization pathway of microparticles into human umbilical cord endothelial cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the mechanisms underlying the incorporation of microparticles(MP) derived from human bone marrow mesenchymal stem cells (MSCs) into human umbilical cord endothelial cells (HUVECs).</p><p><b>METHODS</b>MPs were isolated from the supernatants of MSCs which had exposed to a hypoxia/serum-deprivation condition. Electron microscope was used to identify the MPs. The surface molecule profile was evaluated with the bead-based flow cytometry technique. The expression level of the phosphatidylserine receptor (PSR) was detected by immunofluorescence cytochemistry. MPs were co-cultured with HUVECs in the presence or absence PSR-antibody, and the internalization of MPs was observed with laser scanning microscopy.</p><p><b>RESULTS</b>The MPs derived from MSCs expressed highly PS, while PSR expressed on the surface of HUVECs. The confocal result revealed that MPs could quickly be uptaken by the endothelial cells, and mainly distributed in the cytoplasm surrounding of the nuclei. The internalization of MPs reduced significantly after PSR specific blockage.</p><p><b>CONCLUSION</b>The reaction between PS on the MP and the PSR of HUVECs plays an important role in the internalization of MSC-MPs.</p>

Slowly-adhered primary bone marrow mesenchymal stem cells may exhibit more potent immuno-regulatory activity / 中国实验血液学杂志

<p><b>OBJECTIVE</b>This study was to investigate the relationship between the adherent ability of freshly isolated MSCs with their inhibitory effect on lymphocyte activation.</p><p><b>METHODS</b>Human bone marrow mononucleated cells were maintained in culture for 48 hours, the attached and the non-attached cells were then cultured separately and the adherent cells were collected and passaged. Cellular surface markers were analyzed with flow cytometry. Alkaline phosphatase activity and the intracellular lipid droplets were measured by histological staining, the in vitro osteogenesis and adipogenesis were identified. One-way mixed lymphocyte reaction was used to evaluate the suppressive activity of the adherent cells on lymphocyte proliferation, the prostaglandin E2 level in supernatant of cultured cells was detected by ELISA.</p><p><b>RESULTS</b>Some cells attached to the plastic after the bone marrow mononucleated cells were allowed to adhere for 48 hours. The slowly-attached cells were fibroblast-like in morphology, homogenously positive for CD44 and CD73 and negative for CD31 and CD45. They could be coaxed into osteoblasts and adipoblasts under the standard inductive conditions. These cells were able to inhibit lymphocyte proliferation in mixed lymphocyte reaction and their effect was more potent than those from the adherent cells appeared within 48 hours. The concentration of prostaglandin E-2 in the supernatants of the slowly-adhered cells was significantly higher than that in the MSCs cultured with the traditional method (90.8 ± 10.37 ng/ml vs 70.2 ± 8.98 ng/ml) (P < 0.01).</p><p><b>CONCLUSIONS</b>The MSCs exist in the marrow mononucleated cells after adherent culture for 48 hours, and the MSCs may exhibit more potently inhibitory activity on lymphocyte activation.</p>

Putrescine Promotes Human Marrow Mesenchymal Stem Cells to Differentiate along Osteogenic Pathway / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of putrescine on the growth and differentiation of human bone marrow mesenchymal stem cells (MSC) to develop a new inductive medium mixture for their osteogenic differentiation.</p><p><b>METHODS</b>Human bone marrow MSC were collected from three healthy donors and were used to observe the growth-promoting activity of putrescine with MTT test. Experiments were divided into 3 groups: (1) putrescine group, (2) positive control group (presence of dexamethasone, ascorbate, and glycerol phosphate) and negative group (d-alpha with 5% FCS). The cellular expression level of Runx-2 was detected by PCR assay after the culture was maintained for 1 week. After 2 weeks, the intracellular activity of alkaline phosphatase was revealed by histochemistry staining, the phosphatase activity, and the protein concentration in the cell lysates were also detected. Furthermore, MSC were cultured in the presence of putrescine for 2 weeks and Oil-red O staining was performed to reveal the differentiated adipocytes; the cells induced by the standard agent cocktail were used as the positive control.</p><p><b>RESULTS</b>Putrescine promoted the proliferation of human marrow MSC in a dose-dependent manner. MSC exposed to putrescine at a concentration of 100 µmol/L for 1 week expressed greatly higher level of Runx-2, compared with the negative control. Alkaline phosphatase activity was evidently observed after MSC were maintained in the presence of putrescine for 2 weeks. The phosphatase activity contrasted to the protein content in putrescine-treated MSC was significantly higher than that of the control cells (0.87±0.012 vs 0.52±0.010) (P<0.01), and also greatly higher than that of the positive control (0.83±0.029) (P=0.02). Oil red O staining showed that MSC treated by putrescine did not differentiate into adipoblasts.</p><p><b>CONCLUSION</b>Putrescine can promote the proliferation and osteogenic differentiation of MSC, suggesting the potential application of putrescine as a novel inductive agent for in vitro osteogenesis of MSC.</p>

Effect of microRNA-17-92 cluster on the biological characteristics of K562 cells and its mechanisms / 中国实验血液学杂志

The objective of this study was to explore the effects of microRNA-17-92 on the biological characteristics of K562 cells. The expression of miR-17-92 in K562 cells transfected with miRNA-17-92 mimic was detected by real time PCR. The effect of microRNA-17-92 on K562 cell proliferation was detected by CCK-8 method. Apoptosis of K562 cells was detected by Annexin V-PI labeling. Cell cycle distribution was determined by using flow cytometry. Western blot was performed to determine the protein levels of Crk. The results indicated that the transfection with miR-17-92 mimic increased expression of mature miR-17-92 in K562 cells. Compared with control group, cell proliferation and cell amount in S-phase of miR-17-92 mimic transfected group significantly increased, cell apoptosis decreased. The expression of signal connector protein Crk was greatly up-regulated in miR-17-92-mimic-transfected K562 cells. It is concluded that miR-17-92 can promote proliferation, inhibit apoptosis and regulate the cell cycle of K562 cells.

Protective effect of bone marrow mesenchymal stem cell-derived microvesicles on glutamate injured PC12 cells / 中国实验血液学杂志

This study was aimed to investigate the protective effect of bone mesenchymal stem cell-derived microvesicles (BMMSC-MV) on glutamate injured PC12 cells so as to elucidate the mechanism of the neural damage repair. BMMSC were isolated and purified with density-gradient centrifugation method, BMMSC-MV were harvested from the supernatants of BMMSC by hypothermal ultracentrifugation method. The surface markers of BMMSC reacted against different antibodies were detected by flow cytometry. The morphology features of MV were observed under an electron microscope. Experiment was divided into three groups, one was a control group, and the other two were glutamate-injured group and co-culture group of BMMSC-MV and glutamate-damaged cells respectively. MTT test was used to evaluate the proliferative status of PC12 cells and the AnnexinV-FITC detecting kit and Hoechst33342 were used to detect the apoptosis of PC12 cells in different groups. The results showed that BMMSC isolated from rat bone marrow were highly positive for CD29, CD44 and negative for CD31, CD34 and CD45. The morphology of MV was round and the vesicles were homogenous in size. BMMSC-MV exhibited a protective effect on the excitotoxicity-injured PC12 cells, displaying increase of cell viability, decrease of Annexin-V/PI staining positive and nuclear condensed cells. It is concluded that BMMSC-MV can protect PC12 cells from glutamate-induced apoptosis, suggesting that BMMSC-MV may be a potential candidate for treatment of neurological diseases.This study provides the preliminary experimental and theoretical evidence for use of BMMSC-MV in treatment of neural excited damage.

Exploration of conditions for releasing microvesicle from human bone marrow mesenchymal stem cells / 中国实验血液学杂志

The release of microvesicles(MV) is one of the critical mechanisms underlying the angiogenesis-promoting activity of mesenchymal stem cells(MSC). This study was aimed to explore the appropriate condition under which MSC releases MV. Bone marrow samples from 5 healthy adults were collected, and MSC were isolated, culture-expanded and identified. MSC at passage 5 were suspended in medium without or medium with 10% fetal(FCS) calf serum and seeded into culture dishes. The culture was separately maintained in hypoxia (1% oxygen) or normoxia (around 20% oxygen), and 20 dishes of cells (2×10(6)/dish) were used for each group. The supernatants were collected for MV harvesting. The cell number was counted with trypan blue exclusion test and the protein contents in the MV were determined. MV were identified by observation under an electron microscope. The surface markers on MV were analyzed by flow cytometry. MTT test was performed to observe the pro-proliferative activity of MV that were added into the culture of human umbilical cord vein endothelial cells at a concentration of 10 µg/ml. The results showed that the majority of MV released by MSC were with diameters of less than 100 nm, and MV took the featured membrane-like structure with a hypodense center. They expressed CD29, CD44, CD73 and CD105, while they were negative for CD31 and CD45. The increase multiples of the adherent trypan blue-resistant cells cultured in normoxia with serum, in normoxia without serum, in hypoxia with serum and hypoxia in the absence of serum were 4.05 ± 0.73, 1.77 ± 0.48, 5.80 ± 0.65 and 3.69 ± 0.85 respectively, and the estimated protein contents per 10(8) cells were 463.48 ± 138.74 µg, 1604.07 ± 445.28 µg, 2389.64 ± 476.75 µg and 3141.18 ± 353.01 µg. MTT test showed that MV collected from MSC in hypoxia seemed to promote the growth of endothelial cells more efficiently than those from cells in normoxia. It is concluded that hypoxia can enhance the release of microvesicles from MSC, and cultivation of MSC in hypoxia and medium without serum may provide an appropriate condition for MV harvesting.

Promoting effect of thrombin on proliferation of bone marrow-derived mesenchymal stem cells and its mechanisms / 中国实验血液学杂志

This study was aimed to investigate the growth-promoting activity of thrombin on mesenchymal stem cells (MSC) and its mechanisms. Human bone marrow MSC were cultured in serum-free medium supplemented with graded concentrations of thrombin, and the proliferation status of MSC was detected by MTT test. The expression levels of protease-activated receptors (PAR) and c-MYC gene were detected by PCR. Activated Akt signaling pathway was revealed by Western blot, and specific inhibitors of the signaling pathways were used to confirm the effects. The results showed that thrombin stimulated MSC proliferation in a dose-dependent manner; the minimal concentration of thrombin for stimulating MSC growth was 0.5 U/ml, and the promoting effect reached its maximum when thrombin at a dose of 8 U/ml was employed. PCR results showed that MSC expressed the two types of PAR1 and PAR2. After PAR1 was blocked with a specific inhibitor SCH79797, the growth-promoting effect of thrombin was inhibited, while this phenomenon was not observed when MSC were exposed to FSLLRY-NH2, a specific inhibitor for PAR2. Further experiments showed that after exposure to thrombin, the AKT signaling pathway in MSC was promptly activated, and c-MYC expression was greatly up-regulated. Meanwhile, when LY294002, a specific AKT inhibitor, was added into the culture medium, the up-regulation of c-MYC expression was reduced, accompanied by the low rate of MSC growth. It is concluded that thrombin can stimulate MSC proliferation by eliciting PAR1-mediated AKT activation and subsequent up-regulation of c-MYC expression.

Analysis of CD4(+) T cell function in patients suffered from pulmonary infection in the early phase after haploidentical hematopoietic stem cell transplantation / 中国实验血液学杂志

This study was purposed to investigate the immune state of the patients suffered from pulmonary infection within 6 months after haploidentical hematopoietic stem cell transplantation (hi-HSCT). Adenosine triphosphate (ATP) value in CD4(+) T cells was measured by ImmuKnow method to assess the function of the lymphocytes in peripheral blood of 25 patients at 6 months after hi-HSCT. The results showed that the ATP level in CD4(+) T cells of the patients suffered from pulmonary infection was (179.88 ± 65.41) ng/ml before transplantation, (172.69 ± 118.81) ng/ml at 1 month, (218.15 ± 124.26) ng/ml at 3 months, (313.42 ± 116.29) ng/ml at 6 months after transplantation. The ATP level in CD4(+) T cells of the patients without pulmonary infection was (210.44 ± 94.71) ng/ml before transplantation, and decreased to (193.66 ± 133.69) ng/ml at 1 month and increased gradually to (355.02 ± 43.38) ng/ml at 3 months, (355.73 ± 93.85) ng/ml at 6 months after transplantation. It is concluded that the low ATP value in CD4(+) T cells in patients prior and post hi-HSCT may suggest probability of occurrence for infections, ATP value in CD4(+) T cells may be used as a reference indicator for clinical empirical use of antibiotics.

Therapeutic effect of human bone marrow mesenchymal stem cell lysates on rat arthritis induced by collagen / 中国实验血液学杂志

Our previous work has shown that mesenchymal stem cells (MSC) have little therapeutic effect on rat arthritis induced by collagen. This study was aimed to further investigate whether the MSC lysates exhibit beneficial effects on rheumatoid arthritis. Aliquots of cell lysates from 1×10(7) human bone marrow MSC were intraperitoneally injected into collagen-induced arthritis (CIA) Wistar rats weekly for 4 consecutive weeks. Methotrexate at a dose of 1 mg/kg or normal saline was served as positive and negative controls respectively. On week 4 the symptom scores were recorded and the hind joints of the rats were pathologically examined and X-ray examination was performed. The results showed that on week 4, the symptom scores of the rats that received MSC lysates (6.87 ± 0.83) and MTX (6.44 ± 1.13) were significantly lower than that of control rats (7.33 ± 0.77, P < 0.01). Meanwhile, pathological examination on the involved ankle showed that the synovitis and arthritis scores of MSC lysates and control groups were 2.28 ± 0.48 and 2.28 ± 0.55 respectively, significantly higher than that of MTX treatment rats (0.71 ± 0.48, P < 0.05). However, X-ray examination on the ankle joints showed that the injury score of control rats was 4 ± 0.57, greatly higher than those from MSC lysates (2.71 ± 0.75) and MTX treatment groups (2.57 ± 0.78, P < 0.05 for both groups). It is concluded that MSC lysate infusion has beneficial effects on CIA rat, but the effectiveness seems inferior to MTX.

Analysis of T lymphocyte absolute number and function in the early phase after haploidentical hematopoietic stem cell transplantation / 中国实验血液学杂志

This study was purposed to investigate the immune reconstitution of T-cells in patients who received haploidentical hematopoietic stem cell transplantation (hiHSCT). The peripheral blood was harvested from 22 patients before transplantation and at month 1, 3, 6 after hiHSCT. The proportions of T lymphocyte subtypes including CD3(+), CD4(+), CD8(+), CD45RO(+), and CD45RA(+)CD62L(+) were analyzed by flow cytometry, followed by the calculation of T cell numbers according to the amounts of peripheral blood leukocytes. Adenosine triphosphate (ATP) value in CD4(+) T cells was measured by ImmuKnow method to evaluate the function of lymphocytes. The results showed that the CD3(+) cell absolute value before transplantation was 833.75 ± 359.84/µl, but those values at month 1, 3, 6 after transplantation were 318.87 ± 266.71/µl, 1006.76 ± 512.32/µl and 1296.38 ± 958.77/µl respectively. The CD4(+) cell absolute value before transplantation was 336.99 ± 211.11/µl, but such values at month 1, 3, 6 after transplantation were 45.89 ± 44.21/µl, 142.97 ± 114.85/µl, and 181.78 ± 120.61/µl respectively. The CD8(+) cell absolute value before transplantation was 430.21 ± 159.48/µl, but those values at month 1, 3, 6 after transplantation were 230.44 ± 195.89/µl, 621.64 ± 318.83/µl, and 823.07 ± 633.55/µl respectively. The CD4(+)CD45RO(+) memory T cell absolute value before transplantation was 227.44 ± 73.34/µl, but such values at month 1, 3, 6 after transplantation were 43.47 ± 43.40/µl, 138.69 ± 110.17/µl, 147.73 ± 82.94/µl respectively. The CD8(+)CD45RO(+) memory T cell absolute value before transplantation was 212.70 ± 98.48/µl, but such values at month 1, 3, 6 after transplantation were 184.76 ± 168.65/µl, 445.90 ± 252.50/µl, 519.80 ± 475.53/µl respectively. CD4(+)CD45RA(+)CD62L(+) naive T cell number before transplantation was 68.94 ± 59.74/µl, but such cell numbers at month 1, 3, 6 after transplantation decreased to 2.44 ± 2.93/µl, 3.14 ± 3.48/µl, 23.22 ± 38.38/µl respectively. The CD8(+)CD45RA(+)CD62L(+) naive T cell absolute value before transplantation was 124.82 ± 60.95/µl, but those values at month 1, 3, 6 decreased to 19.37 ± 17.71/µl, 76.63 ± 50.85/µl, and 114.49 ± 174.29/µl respectively. The ATP value in CD4(+) T cells decreased to 210.19 ± 119.37 ng/ml at month 1 after transplantation and increased to 280.62 ± 110.03 ng/ml at month 3, and 357.28 ± 76.18 ng/ml at month 6 after transplantation. It is concluded that CD8(+) memory T cell reconstruction contributes critically to T cell recovery early after hiHSCT, while the thymic output function remains low. However, T cell function recovers to normal range at month 3 after transplantation.

Effects of tumor necrosis factor-α on immunoregulatory activities of mesenchymal stem cells in vitro and in vivo / 中国实验血液学杂志

Mesenchymal stem cells (MSC) are characterized by their potent immuno-regulatory activity, however our previous data have shown that MSC have no therapeutic effects on collagen-induced arthritis (CIA). To further clarify the complexity, the effects of tumor necrosis factor-alpha (TNF-α) on the in vitro and in vivo immunoregulatory activity of MSC were investigated in this study, as TNF-α is recognized as the key factor in the development of rheumatoid arthritis. The nuclear translocation of the inflammation-associated factor NF-κB was observed after human umbilical cord MSC were treated with TNF-α and the cell proliferation status was assessed by MTT test. The inhibitory effects of MSC or TNF-α-treated MSC on the mixed lymphocyte reaction, in which Wistar rat spleen mononuclear cells were served as the responders and the splenocytes from SD rat spleens as the stimulators, were also determined by the MTT test. Further, the therapeutic potentials of MSC or TNF-α-treated MSC were observed in a Wistar rat CIA model. The results showed that NF-κB translocated into the nuclei promptly after TNF-α treatment, though TNF-α had little effect on the MSC proliferation. MSC, whether pre-stimulated by TNF-α or not and when different doses were tested, exhibited obviously inhibitory effects on the proliferation of the lymphocytes (P < 0.001 for all groups tested), while MSC-treated by TNF-α displayed more potent suppression especially when low-density were used. Unexpectedly, the infiltration of inflammatory cells into the involved knees was aggravated by cell treatment and the pathological scores were significantly higher than those of controls (P < 0.05). It is concluded that the TNF-α exhibits different effects on immune regulation activity of MSC, and its underlying mechanism needs to further investigate.

Human bone marrow mesenchymal stem cells have little preventive or therapeutic effect on rat arthritis induced by collagen / 中国实验血液学杂志

The aim of this study was to investigate if transfusion of mesenchymal stem cells (MSC) could exhibit beneficial effects on rheumatoid arthritis. Human bone marrow MSC were intraperitoneally injected into Wistar rats with collagen-induced arthritis at a dose of 10(7) on the next day (preventive group) or 2 weeks (treatment group) after collagen II induction, once a week for 2 weeks (preventive group) or 4 weeks (treatment group). The control group was given normal saline (NS) at corresponding time. The symptom scorings were documented weekly from the second week of the induction. On week 6, the hind joints of the rats were pathologically examined and the activation status of splenocytes was analyzed by flow cytometry. The results showed that all the rats developed arthritis and subsequent joint abnormality. On the sixth week, symptom scores of the rats that received MSC preventive (9.5 ± 0.5) or therapeutic (9.4 ± 0.6) infusions had no significant difference between each other, but were significantly greater than those of the NS controls (7.6 ± 0.6, P < 0.05). Consistently, pathological examination on the involved knees showed that the synovitis and arthritis scorings of MSC treated rats were greatly elevated compared with NS controls. Furthermore, the ratios of CD86(+) cells in the spleens of MSC prevention, MSC treatment and NS control groups were (4.16 ± 1.48), (4.06 ± 1.97) and (4.15 ± 2.04) respectively, while those of CD11b/c(+)CD86(+) cells were (1.04 ± 0.68), (0.95 ± 0.56) and (0.98 ± 0.44), all of which were significantly higher than those of healthy controls [(0.97 ± 0.18) and (0.30 ± 0.17), P < 0.05 for both parameters]. It is concluded that MSC infusion has little beneficial effects on collagen-induced arthritis in rats, conversely, MSC therapy aggravated the damage of the involved joints, its underlying mechanisms need to be further investigated.

Effect of human bone marrow mesenchymal stem cell transplantation on hematopoietic recovery of irradiated mice / 中国实验血液学杂志

This study was aimed to investigate the effect of human bone marrow mesenchymal stem cells (hBMMSC) on the hematopoietic recovery of sublethally irradiated mice. Female BALb/c mice irradiated with (60)Co γ-ray at a single dose of 6 Gy received graded doses of hBMMSC (1×10(5), 1×10(6) and 5×10(6)) by intravenous infusion. The counts of leukocytes, platelets, erythrocytes and hemoglobin level in peripheral blood, the amount of bone marrow hematopoietic progenitors, and the serum levels of human TPO, SCF and G-CSF as well were evaluated at different time points after transplantation. The results showed that hBMMSC infusion had little protective effect on the survival of irradiated mice. Compared with the control mice, the peripheral blood cell counts of hBMMSC-treated mice were not obviously elevated during 3 weeks after infusion, however, blood cell counts were significantly greater at 4 weeks after cell treatment (P < 0.05). The amount of colony-forming unit of mononuclear cells and granulocyte/monocytes in bone marrow of mice that received middle and high doses of hBMMSC were dramatically greater than that in control mice (P < 0.05). Two days after hBMMSC administration, human G-CSF and SCF could be detected in the sera from hBMMSC-treated mice, and the G-CSF concentration of mice that received high-dose hBMMSC was significantly higher than that in other groups (P < 0.01). Nevertheless, human TPO was undetectable in the sera of all mice tested and serum human G-CSF and SCF could not be detected on days 9 and 16 in all groups. It is concluded that hBMMSC may promote the hematopoietic recovery of irradiated mice, probably by transient secretion of hematopoiesis-associated factors by the implanted cells.