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.

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.

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.

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.