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BACKGROUND:Although bone marrow mesenchymal stem cels from multiple myeloma patients present a variety of abnormalities, it is unclear how these abnormal mesenchymal stem cels influence the chemotactic function of myeloma cel lines. OBJECTIVE:To investigate thein vitro effects of bone marrow mesenchymal stem cels from normal donors versus multiple myeloma patients on the chemotactic capacity of myeloma cel lines. METHODS:In vitro cultured bone marrow mesenchymal stem cels derived from either normal donors (N-MSCs group) or newly-diagnosed multiple myeloma patients (MN-MSCs group) were directly co-cultured with U266 cels, in the presence or absence of bortezomib; and then harvested U266 cels were assayed for Transwel migration and mRAN expression of chemotaxis-related genes. U266 Transwel migration to conditioned medium derived from either N-MSCs or MN-MSCs was also tested. RESULTS AND CONCLUSION:After co-cultured with N-MSCs or MN-MSCs, U266 cels harvested from MN-MSCs group showed increased spontaneous Transwel migration and up-regulated CCR1 mRNA level than those from N-MSCs group (P < 0.05), whatever bortezomib was present or not. However, there was no evident difference between U266 cel Transwel migration to conditioned medium derived from either MM-MSCs group or N-MSCs group. Our study implies that there may be some intrinsic aberrance in bone marrow mesenchymal stem cels derived from multiple myeloma patients, which can modulate the chemotactic migration of myeloma cel lines when they directly interact with each other.
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Objective To investigate the mechanism of tumor necrosis factor-α (TNF)-α inhibiting osteo blastdifferentiation of mesenchymal stem cells (BMMSCs) in the pathogenesis of osteoporosis in the mouse model of systemic lupus erythematosus (MRL/lpr). Methods The femurs of MRL / lpr and C3He/HeJ mice were isolated, the bone structure were examined by hematoxylin-eosin (HE) staining. The proteins of TNF-α, NF-κB P50, bone morphogenetic protein -2 (BMP-2) and PSmad1/5/8 were measured by immunohistochemical stain. Bone marrow mesenchymal stem cells (BMMSCs) were isolated. After BMMSCs grew on the cover slips, the proteins on top of it were evaluated by immunohistochemistry stain. Moreover, the alkaline phosphatase (ALP) staining was employed for the measurement of the early osteogenic differentiation. BMMSCs together with hydroxyapatite were embedded subcutaneously in the nude mice and eight weeks later, the ectopic bone formation was evaluated. The recombinant human tumor necrosis factor receptor type Ⅱantibody fusion protein (etanercept) or normal saline was subcutaneous injected to the mice with lupus. After four weeks, the expression of these proteins was observed and the ectopic bone formation was investigated. Image-Pro plus 6.0 software was employed for imagine analysis, and Studentˊs t-test was used to test the differences between 2 independent groups. Results MRL/lpr mice showed decreased volume of cortex and the percentage of cortex to the volume of bone of MRL/lpr mice was significantly lower compared to control groups and with C3He/HeJ mice (13.96±0.25 vs 23.61±0.71, n=3, P0.05). The expressions of TNF-α and NF-κB P50 in BMMSCs of MRL/lprl mice were higher than those of the C3He/HeJ (0.184±0.021 vs 0.136±0.013, 0.132±0.021 vs 0.097± 0.014, n=3, P0.05). The ectopic bone formation of BMMSCs of the etanercept injected MRL/lpr mice was higher than that of the normal saline injected mice, however, it was lower than that of the C3He/HeJ mice. Conclusion TNF-α inhibits osteoblast differentiation of mesenchymal stem cells by depressing Smad signaling which may contribute to the osteoporosis of the lupus mice.
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Objective To investigate the expression and significance of transforming growth factor-β1 (TGF-β1) gene in bone marrow mesenchymal stem cell (BMMSC) derived from patients with multiple myeloma (MM).Methods BMMSC of 7 MM patients and 10 patients with iron deficiency anemia were cultured in vitro.The morphology of BMMSC was observed and the growth curve was portrayed according to the daily results of BMMSC proliferation.Total RNA was extracted from BMMSCs and transcription of TGF-β1 gene in BMMSC was measured by reverse transcription-PCR.Results The proliferative activity of BMMSC was not significantly different between the two groups,but expression of TGF-β1 gene of BMMSC was higher in MM patients (0.01241±0.00419) than the control group (0.00122±0.00030) (t =3.218,P ＜ 0.05).Conclusion The abnormally high expression of TGF-β31 gene in BMMSCs could contribute to the pathogenesis of MM.
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Objective To investigate the immunoregulatory effects of mesenchymal stem cells (MSCs)on peripheral blood T lymphocytes from patients with systemic lupus erythematosus(SLE)in vitro and their potential mechanism.Methods MSCs were isolated from the bone marrow of 3 healthy human volunteers,cultivated and identified.Under phytohemagglutinin(PHA)stimulating,peripheral blood T lymphocytes from 8 patients with SLE were treated with MSCs with the T lymphocyte/MSC ratio being 50:1 in group B and 5:1 in group C or without MSCs(group A).MTT assay was used to detect the proliferation of T lymphocytes.flow cytometry to analyze the expressions of surface markers CD152 and CD28 on T lymphocytes.and real time PCR to measure the mRNA expressions of interleukin-6 and interferon-γ,in the T lymphocytes.Results MSCs could markedly inhibit the proliferation of T lymphocytcs.The proliferation of T lymphocytes expressed as absorbance value at 570 nm was 0.484±0.032 in group B.0.308±0.025 in group C,significantly lower than that in group A(0.765±0.036,both P＜0.05),and significant difference was also observed between group C and B(P＜0.05).In the case of the percentage of CD28 positive T lymphocytes.group B and C were significantly lower than group A(60.39%±3.92%and 45.05%±3.46%vs 74.73%±3.74%,both P＜0.05),and group B significantly differed from group C(P＜0.05).MSCs had no obvious effect on the expression of CD152 on T lymphocytes,but significantly suppressed the mRNA expression of interleukin-6 and interferon-γ(both P＜0.05).and the suppressive effect was enhanced with the incrgase in MSC count.ConclusionsMSCs exert an immunosuppressive effect on T lymphocytes from patients with SLE,likely through inhibiting the proliferation,CD28 expression,interleukin-6 and interferon-γ mRNA expression of T lymphocytes.