Taketoshi Kushida

Treating Achilles Tendon Rupture in Rats with Bone-Marrow-Cell Transplantation Therapy

BACKGROUND Bone marrow cells possess multipotentiality and have been used for several treatments. We hypothesized that bone marrow cells might differentiate into regenerated tendon and that several cytokines within bone marrow cells might accelerate tendon healing. Therefore, we treated Achilles tendon ruptures in a rat model with transplantation of whole bone marrow cells. METHODS Nine F344/Nslc (Fisher) rats were the source of bone marrow cells and mesenchymal stem cells as well as normal Achilles tendons. Eighty-seven Fisher rats were used for the experiments. The rats were divided into three groups: the BMC group (bone marrow cells injected around the tendon), the MSC group (mesenchymal stem cells injected around the tendon), and the non-treated control group (incision only). Outcome measures included mechanical testing, collagen immunohistochemistry, histological analysis, and reverse transcription-polymerase chain reaction to detect expression of transforming growth factor-β (TGF-β) and vascular endothelial growth factor (VEGF). RESULTS The ultimate failure load in the BMC group was significantly greater than that in the non-treated or the MSC group at seven days after incision (3.8 N vs. 0.9 N or 2.1 N, p < 0.016) and at fourteen days after incision (10.2 N vs. 6.1 N or 8.2 N, p < 0.016). The ultimate failure load in the BMC group at twenty-eight days after incision (33.8 N) was the same as that of normal tendon (34.8 N). The BMC group demonstrated stronger staining for type-III collagen at seven days after incision and stronger staining for type-I collagen at twenty-eight days than did the MSC group. Expression of TGF-β and VEGF in the BMC group was significantly increased compared with that in the other groups at four days after incision (TGF-β: 1.6 vs. 1.3 or 0.6, p < 0.01; VEGF: 1.7 vs. 1.1 or 0.9, p < 0.01). CONCLUSIONS Transplantation of whole bone marrow cells may be a better and more readily available treatment for Achilles tendon rupture than cultured mesenchymal stem cells.

Comparative analyses of megakaryocytes derived from cord blood and bone marrow

Thrombocytopenia is typically observed in patients undergoing cord blood transplantation. We hypothesized that delayed recovery of the platelet count might be caused by defects in the megakaryocytic differentiation pathway of cord blood progenitors. To test this hypothesis, we compared the features of in vitro megakaryocytopoiesis between cord blood progenitors and those in bone marrow cells after isolation of CD34+ cells as progenitors. The proliferative responses of the progenitors in cord blood are higher than those in bone marrow cells in the presence of interleukin (IL)‐3, stem cell factor (SCF) and thrombopoietin (TPO). However, the ability to generate mature megakaryocytes was higher in bone marrow progenitors than in cord blood in the same in vitro culture system, when examined by the expression of CD41, polyploidy and proplatelet formation. Furthermore, an earlier induction of c‐mpl protein, a receptor for TPO, was observed in the progenitors from bone marrow than in those from cord blood in the presence of SCF and IL‐3. Therefore, the ability to generate mature megakaryocytes in bone marrow progenitors is superior to that in cord blood, and the delayed engraftment of platelets after cord blood transplantation might be attributed to the features of cord blood megakaryocyte progenitors.

A New Method for Bone Marrow Cell Harvesting

To minimize contamination of bone marrow cells (BMCs) with T cells from the peripheral blood, a new “perfusion method” for collecting BMCs is proposed using cynomolgus monkeys. Two BM puncture needles are inserted into a long bone such as the humerus, femur, or tibia. One needle is connected to an extension tube and the end of the tube is inserted into a culture flask to collect the BM fluid. The other needle is connected to a syringe containing 30 ml of phosphate‐buffered saline. The solution is pushed gently from the syringe into the medullary cavity, and the medium containing the BM fluid is collected into the culture flask. There is significantly less contamination with peripheral blood, determined from the frequencies of CD4+ and CD8+ T cells, when using this method (<6%) than when using the conventional method (>20%) consisting of multiple BM aspirations from the iliac crest. Furthermore, the number and progenitor activities of the cells harvested using this “perfusion method” are greater than those harvested using the conventional aspiration method. This perfusion method was carried out 42 times using 15 cynomolgus monkeys, and no complications such as pulmonary infarction or paralysis were observed. These findings suggest that the “perfusion method” is safe and simple and would be of great advantage in obtaining pure BMCs, resulting in a less frequent occurrence of acute graft‐versus‐host‐disease in allogeneic BM transplantation.

Comparison of bone marrow cells harvested from various bones of cynomolgus monkeys at various ages by perfusion or aspiration methods: a preclinical study for human BMT.

Using cynomolgus monkeys, we have previously established a new method for harvesting bone marrow cells (BMCs) with minimal contamination of the BMCs with T cells from the peripheral blood. We originally conducted this new “perfusion method” in the long bones (the humerus, femur, and tibia) of cynomolgus monkeys.

Successful allogeneic leg transplantation in rats in conjunction with intra-bone marrow injection of donor bone marrow cells.

Background. We have recently established a new method for bone marrow transplantation (BMT) in mice: bone marrow cells are directly injected into the intra-bone marrow (IBM) cavity. IBM-BMT induces persistent donor-specific tolerance and enhances the rapid recovery or reconstitution of the hematolymphoid system of donor origin without any signs of graft-versus-host disease (GVHD) or graft failure. Furthermore, the prior injection of fludarabine can reduce the irradiation dose to the sublethal level (4.5 Gy×2). Therefore, we hypothesize that IBM-BMT plus fludarabine is applicable to allogeneic leg transplantation in rats. Methods. Brown Norway (BN; RT1An) rats were injected intravenously with 50 mg/kg of fludarabine phosphate, followed by sublethal fractionated irradiation (4.5 Gy×2) 1 day before IBM-BMT. The hind limbs from Fischer 344 (F344; RT1Al) rats were transplanted on day 0, and bone marrow cells (3×107 cells/50 &mgr;L) obtained from the donor F344 rats were injected into the bone marrow cavity of the left tibias of the recipient BN rats. Results. The hematolymphoid cells in the recipient BN rats were completely reconstituted by the cells of the donor F344 rats. The limbs transplanted from the donor F344 rats were accepted for >1 year without any clinical signs of rejection (10 of 10). The lymphocytes of the BN rats showed tolerance to both donor-type and recipient-type major histocompatibility complex determinants in mixed lymphocyte reaction, but showed a significant response to the third-party major histocompatibility complex determinants. Conclusions. Using a combination of the injection of fludarabine, low-dose irradiation, and IBM-BMT, we have succeeded in allogeneic limb transplantation without using any immunosuppressants after the operation. This strategy would be applicable to the transplantation of other vascularized organs in humans.

Crucial Role of Donor‐Derived Stromal Cells in Successful Treatment for Intractable Autoimmune Diseases in MRL/lpr Mice by BMT Via Portal Vein

We have recently established a new bone marrow transplantation (BMT) method for the treatment of intractable autoimmune diseases in MRL/lpr mice; the method consists of fractionated irradiation (5.5 Gy × 2), followed by BMT of whole bone marrow cells (BMCs) from allogeneic C57BL/6 mice via the portal vein (abbreviated as 5.5 Gy × 2 + PV). In the present study, we investigate the mechanisms underlying the early engraftment of donor‐derived cells in MRL/lpr mice by this method. In the mice treated with this method, the number of donor‐derived cells possessing the mature lineage (Lin) markers rapidly increased in the BM, spleen, and liver; almost 100% were donor‐derived cells by 14 days after the treatment. The number of donor‐derived hemopoietic progenitor cells (defined as c‐kit+/Lin− cells) increased in the BMCs, hepatic mononuclear cells, and especially spleen cells by 14 days after the treatment. Simultaneously, hemopoietic foci adjoining donor‐derived stromal cells were observed in the liver when injected via the PV, but not via the peripheral vein (i.v.). When adherent cell‐depleted BMCs were injected via the PV, recipients showed a marked reduction in the survival rate. However, when mice were transplanted with adherent cell‐depleted BMCs with cultured stromal cells, all the recipients survived.

Induction of Senile Osteoporosis in Normal Mice by Intra‐Bone Marrow‐Bone Marrow Transplantation from Osteoporosis‐Prone Mice

A P6 substrain of the senescence accelerated mouse (SAMP6) spontaneously develops osteoporosis early in life. These mice show the clinical signs of osteoporosis, such as elevated levels of urinary deoxypyridinoline (Dpd), decreased bone mineral density (BMD), and a significant loss of trabecular and cortical bone thickness at 12 months of age. Here, we describe the transfer of osteoporosis to a normal strain by the injection of bone marrow cells from SAMP6 donors directly into the bone marrow cavity (intra‐bone marrow‐bone marrow transplantation [IBM‐BMT]). More than 1 month after IBM‐BMT, hematolymphoid cells were completely reconstituted by donor‐derived cells, and bone marrow stromal cells that could differentiate into osteocytes were also found to be of donor origin. In addition, the recipient C57BL/6 mouse showed the features of osteoporosis in the trabecular bone. Decreases in BMD and increases in urinary Dpd were also observed. When the message levels of cytokines (interleukin [IL]‐11, IL‐6, receptor activator of NF‐κB ligand [RANKL], osteoprotegerin, macrophage–colony‐stimulating factor, and insulin‐like growth factor‐1) were examined by reverse transcription‐polymerase chain reaction (RT‐PCR) and real‐time RT‐PCR analysis, IL‐6 and IL‐11 were reduced to a level similar to that in SAMP6 mice, whereas that of RANKL was increased. These findings indicate that not only the hemopoietic system but also the bone marrow microenvironment are reconstituted as a result of IBM‐BMT, and suggest that the development of senile osteoporosis might be attributable to “stem cell disorders.”

New Strategies for Anterior Cruciate Ligament Partial Rupture Using Bone Marrow Transplantation in Rats

The purpose of this study was to compare anterior cruciate ligament (ACL) regeneration between animal groups subjected to intra-articular injection of fresh whole bone marrow cells (BMCs), cultured mesenchymal stem cells (MSCs), or saline. Partially transected ACLs in Fischer 344/Nslc rats were prepared, followed by injection of BMCs, MSCs, or saline into the articular cavity at 1 week after transection. Donor cells expressing green fluorescent protein were detected in the recipients transected ACLs at 4 weeks in the BMC and MSC groups, and their ACLs appeared almost normal histologically. Further, there were significantly more mature spindle cells in the BMC group than in the saline group at 4 weeks. Biomechanically, the tensile strength in the BMC group reached near normal levels at 4 weeks after injection. The levels of transforming growth factor-β1 in the ACL tissue and knee joint fluid in the BMC group were increased significantly compared with that of the saline group at 4 weeks as detected by immunohistochemical analysis. In conclusion, intra-articular bone marrow transplantation using fresh whole BMCs is an effective treatment for ACL partial rupture. This therapy is easy to apply in a clinical setting because no culture system is required for collecting MSCs.

Prevention of corticosteroid-induced osteonecrosis in rabbits by intra-bone marrow injection of autologous bone marrow cells.

OBJECTIVES Femoral head osteonecrosis (ON) is a serious complication of steroid administration. We evaluated bone marrow transplantation (BMT) for preventing corticosteroid-induced ON. METHODS Rabbits, injected with methylprednisolone (MPSL; 20 mg/kg), were divided into four groups: (i) MPSL alone; MPSL injection only, (ii) MPSL+needling; 2 days after MPSL injection, a hole (1.2 mm diameter) was drilled from the outer cortex 2.5 cm distal to the proximal end of the greater trochanter, (iii) MPSL+saline; 2 days after MPSL injection, 2 ml saline was injected directly into the bone marrow cavity, and (iv) MPSL+BMT; 2 days after MPSL injection, 1 x 10(7)/2 ml bone marrow cells (BMCs) were injected directly into the bone marrow cavity. Platelets, fibrinogen, prothrombin time and total cholesterol in peripheral blood were measured before and after treatment. Tissues were stained with haematoxylin and eosion and terminal deoxynucleotidyl-mediated deoxyuridine triphosphate nick-end labelling stain and immunostained for VEGF, while cell proliferation and viability of whole BMCs in the femur were analysed by cell cycle analysis and [(3)H]-thymidine uptake. RESULTS The ON incidence in rabbits treated with MPSL alone, MPSL+needling and MPSL+saline was 72.7, 70.0 and 66.7%, respectively, while in the MPSL+BMT group, the incidence was 0%. Serological findings in the MPSL+BMT group were almost normalized. VEGF and TUNEL staining were reduced in the MPSL+BMT group compared with all other groups. There were significantly fewer BMCs in G1 phase from the MPSL+BMT group than the other groups, while uptake of [(3)H]-thymidine was significantly increased. CONCLUSION Direct injection of autologous BMCs into femurs prevents corticosteroid-induced ON following treatment with high-dose, short-term steroids.

Autopsy case of primary choriocarcinoma of the urinary bladder.

Choriocarcinomas usually develop in the uterus and ovaries in the female, being extremely rare in the extragenital organs in the male. Extragenital choriocarcinomas in the male usually develop in the mediastinum or retroperitoneum. The frequency of choriocarcinoma in the urinary bladder is extremely low. The purpose of the present paper was to report an autopsy case of choriocarcinoma in the urinary bladder in the male. An 81‐year‐old male patient with macrohematuria was first diagnosed with transitional cell carcinoma (TCC). At autopsy a hemorrhagic necrotic tumor, which was found in the urinary bladder with metastatic lesions in the lungs, was diagnosed as choriocarcinoma microscopically. There was no evidence for choriocarcinoma derived from any other organs than the urinary bladder, although there were metastatic lesions in both lungs and the direct invasion into the prostate. From these findings it is concluded that the tumor was a primary choriocarcinoma in the urinary bladder in a male patient. Choriocarcinoma of the urinary bladder is very rare, but the prognosis is extremely poor in comparison with TCC even in the urinary bladder. Therefore, it is essential to clearly discriminate between choriocarcinomas and TCC.