Objective: To establish an intramedullary transplantation model of primary megakaryocytes to evaluate the platelet-producing capacity of megakaryocytes and explore the underlying regulatory mechanisms. Methods: Donor megakaryocytes from GFP-transgenic mice bone marrow were enriched by magnetic beads. The platelet-producing model was established by intramedullary injection to recipient mice that underwent half-lethal dose irradiation 1 week in advance. Donor-derived megakaryocytes and platelets were detected by immunofluorescence staining and flow cytometry. Results: The proportion of megakaryocytes in the enriched sample for transplantation was 40 to 50 times higher than that in conventional bone marrow. After intramedullary transplantation, donor-derived megakaryocytes successfully implanted in the medullary cavity of the recipient and produce platelets, which showed similar expression of surface markers and morphology to recipient-derived platelets. Conclusion: We successfully established an in vivo platelet-producing model of primary megakaryocytes using magnetic-bead enrichment and intramedullary injection, which objectively reflects the platelet-producing capacity of megakaryocytes in the bone marrow.
Animals ; Blood Platelets ; Bone Marrow ; Bone Marrow Cells ; Bone Marrow Transplantation ; Humans ; Megakaryocytes/metabolism* ; Mice

Macrophages have been shown to have pleiotropic functions in various pathophysiologies, especially in terms of anti-inflammatory and regenerative activity. Recently, the novel functions of bone marrow resident macrophages (called osteal macrophages) were intensively studied in bone development, remodeling and tissue repair processes. This review discusses the current evidence for a role of osteal macrophages in bone modeling, remodeling, and fracture healing processes.
Bone Development ; Bone Marrow ; Bone Remodeling ; Fracture Healing ; Macrophages* ; Metabolism*

No abstract available.
Biopsy ; Biopsy, Needle ; Bone Marrow/metabolism ; Bone Marrow/pathology ; Bone Marrow Diseases/diagnosis ; Bone Marrow Examination* ; Comparative Study ; Diagnosis, Differential ; Hematologic Diseases/diagnosis* ; Human ; Kidney Failure, Chronic/pathology

OBJECTIVE: To assess the efficacy of GelMA hydrogel loaded with bone marrow stem cell-derived exosomes for repairing injured rat knee articular cartilage. METHODS: The supernatant of cultured bone marrow stem cells was subjected to ultracentrifugation separate and extract the exosomes, which were characterized by transmission electron microscopy, particle size analysis and Western blotting of the surface markers. The changes in rheology and electron microscopic features of GelMA hydrogel were examined after loading the exosomes. We assessed exosome release from the hydrogel was detected by BCA protein detection method, and labeled the exosomes with PKH26 red fluorescent dye to observe their phagocytosis by RAW264.7 cells. The effects of the exosomes alone, unloaded hydrogel, and exosome-loaded hydrogel on the polarization of RAW264.7 cells were detected by q-PCR and immunofluorescence assay. We further tested the effect of the exosome-loaded hydrogel on cartilage repair in a Transwell co-culture cell model of RAW264.7 cells and chondrocytes in a rat model of knee cartilage injury using q-PCR and immunofluorescence assay and HE and Masson staining. RESULTS: GelMA hydrogel loaded with exosomes significantly promoted M2-type polarization of RAW264.7 cells (P < 0.05). In the Transwell co-culture model, the exosome-loaded GelMA hydrogel significantly promoted the repair of injured chondrocytes by regulating RAW264.7 cell transformation from M1 to M2 (P < 0.05). HE and Masson staining showed that the exosome-loaded hydrogel obviously promoted cartilage repair in the rat models damage. CONCLUSION GelMA hydrogel loaded with bone marrow stem cell-derived exosomes can significantly promote the repair of cartilage damage in rats by improving the immune microenvironment.
Animals ; Bone Marrow Cells ; Cartilage ; Chondrocytes ; Exosomes ; Hydrogels/metabolism* ; Rats

Multiple myeloma (MM) is a malignant proliferative disease of plasma cells. Bone marrow mesenchymal stem cells (MSC) play an important role in the progression of MM. Compared with normal donor derived MSC (ND-MSC), MM patients derived MSC (MM-MSC) exhibit abnormalities in genes, signaling pathways, protein expression levels and cytokines secreted by themselves. Moreover, the exosomes of MM-MSC can interact with the bone marrow microenvironment. The above reasons can lead to MM cell proliferation, chemoresistance, impaired osteogenic differentiation of MM-MSC, and affect the immunomodulatory capacity of MM patients. In order to further understand the pathogenesis and related influencing factors of MM, this paper reviews the latest research progress of MM-MSC.
Humans ; Multiple Myeloma/pathology* ; Osteogenesis ; Mesenchymal Stem Cells ; Cell Differentiation ; Bone Marrow/metabolism* ; Bone Marrow Cells/metabolism* ; Tumor Microenvironment

BACKGROUND: The loss of bone mass is usually detected after bone marrow transplantation(BMT), particularly during the early post-transplant period. We recently reported that enhanced bone resorption following BMT was related to both the steroid dose and increase in IL-6. It was also suggested damage of the marrow microenvironment due to myeloablation and changes in bone growth factors contribute to post-BMT bone loss. Recently, the interactions of OPG and RANKL have been reported to be crucial in osteoclastogenesis and therefore in bone homeostasis. There are few data on the changes in RANKL/OPG status during the post-BMT period. This study investigated the changes in the levels of RANKL and OPG during the post-BMT period, and also assessed whether the changes in these cytokine levels actually influenced bone turnover and post-BMT bone loss. METHODS: We prospectively investigated 110 patients undergoing allogenic BMT and analyzed 36 (32.4+/-1.3 years, 17 men and 19 women) where DEXA was performed before and 1 year after the BMT. The serum bone turnover marker levels were measured before and 1, 2, 3, 4 and 12 wks, 6 Ms, and 1 yr after the BMT. The serum sRANKL and OPG levels were measured in all patients before and 1, 3 and 12 wks after the BMT. RESULTS: The mean bone losses in the lumbar spine and total proximal femur, which were calculated as the percent change from the baseline to 1 yr, were 5.2(P<0.01) and 11.6%(P<0.01), respectively. The mean serum ICTP, a bone resorption marker, increased progressively until 3 and 6 months after the BMT, but decreased gradually thereafter, reaching the basal values after 1 year. The serum osteocalcin levels decreased progressively until 3 wks after the BMT, then increased transiently at 3 and 6 Ms, but returned to the basal level by 1 yr. The serum sRANKL and OPG levels had increased significantly by weeks 1 and 3 compared with the baseline(P<0.01), but decreased at 3 months. The sRANKL/OPG ratio increased progressively until 3 weeks, but then decreased to the basal values. During the observation period, the percent changes from the baseline in the serum RANKL levels and RANKL/OPG ratio showed positive correlations with the percent changes from the baseline serum ICTP levels. Patients with higher RANKL levels and RANKL/OPG ratio during the early post-BMT period lost more bone mass at the lumbar spine. CONCLUSION: In conclusion, dynamic changes in the sRANKL and OPG levels were observed during the immediate post-BMT period, which were related to a decrease in bone formation and loss of L-spine BMD during the year following the BMT. Taken together, these results suggest that increased sRANKL levels and sRANKL/OPG ratios could be involved in a negative balance in bone metabolism following BMT.
Bone Density ; Bone Development ; Bone Marrow Transplantation* ; Bone Marrow* ; Bone Resorption ; Femur ; Homeostasis ; Humans ; Interleukin-6 ; Male ; Metabolism* ; Osteocalcin ; Osteogenesis ; Osteoporosis ; Prospective Studies ; Spine

Bone marrow stem cells (BMSC), known for its multipotency to differentiate into various mesenchymal cells such as chodrocyte, osteoblasts, adipocytes, etc, have been actively applied in tissue engineering. BMSC have been successfully isolated from bone marrow aspirate and bone marrow scraping from patients of various ages (13-56 years) with as little as 2ml to 5ml aspirate. BMSC isolated from our laboratory showed the presence of a heterogenous population that showed varying prevalence of surface antigens and the presence of telomerase activity albeit weak. Upon osteogenic induction, alkaline phosphatase activity and mineralization activity were observed.
Bone Marrow Cells/cytology ; *Bone Marrow Transplantation ; Bone Regeneration/physiology ; *Bone Transplantation ; Cell Differentiation/physiology ; *Mesenchymal Stem Cell Transplantation ; Telomerase/metabolism ; *Tissue Engineering

The genesis and development of leukemia not only associate to intrinsic factors, but also relate with the fibrous hyperplasia in the bone marrow. This review mainly focuses on the interaction between fiber-producing cells and leukemia cells, the relationship between fibrous hyperplasia and prognosis of leukemia, the regulation of TGF-beta, PDGF and other cytokines, the underlying mechanism of fibrous hyperplasia so as to explore the potential therapeutic targets for improving the prognosis of leukemia.
Bone Marrow ; pathology ; Bone Marrow Cells ; cytology ; Cell Differentiation ; Cytokines ; metabolism ; Fibroblasts ; cytology ; Humans ; Leukemia ; pathology ; Platelet-Derived Growth Factor ; metabolism ; Transforming Growth Factor beta ; metabolism

Reactive oxygen species (ROS) is a kind of molecules derived by oxygen in the metabolic process of aerobic cells, which mainly includes superoxide, hydroxyl radicals, alkoxyl, hydrogen peroxide, hypochlorous acid, ozone, etc. They can destroy the structure and function of cells through the damage of biological macromolecules such as DNA, proteins and the lipid peroxidation. ROS also can regulate the proliferation, differentiation and apoptosis of cells through several signaling pathways and participate in fibrogenesis of many organs including hepatic and pulmonary fibrosis. Recent study shows that ROS might have an important effect on the forming of myelofibrosis. Consequently, ROS plays a significant role in the fibrogenesis of tissues and organs. In this review, the relevance between ROS and common tissues and organs fibrosis is summarized.
Animals ; Bone Marrow ; pathology ; Bone Marrow Diseases ; metabolism ; pathology ; Fibrosis ; Humans ; Liver ; pathology ; Liver Cirrhosis ; metabolism ; pathology ; Lung ; pathology ; Pulmonary Fibrosis ; metabolism ; pathology ; Reactive Oxygen Species

Bone marrow mesenchymal stem cells (MSCs) are somatic stem cells that can differentiate into progenies of multiple lineages. They play an important role in hematopoiesis and stem cell therapy due to their multi-lineage potentials and immunomodulatory properties. Oxidative stress is a disturbed redox state caused by accumulation of reactive oxygen species. It can induce the senescence and apoptosis of MSCs via phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) and p53 pathways, and inhibit the proliferation and differentiation of MSCs through apurinic/apyrimidinic endonuclease/redox factor 1 (APE/REF-1) and extracellular signal-regulated kinase (ERK) pathways. Furthermore, using anti-stress medication and hypoxic preconditioning, the functions of MSCs can be further enhanced. Accordingly, further studies on the effect of oxidative stress on MSCs and its signaling pathways may be meaningful for the treatment of hematologic diseases and for improving stem cell therapy.
Bone Marrow Cells ; cytology ; metabolism ; Humans ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Oxidative Stress ; Signal Transduction