RESUMO
The osteoporotic fracture is characterized by difficult treatment and poor prognosis. The studies of bone biology show that bone microenvironment changes during osteoporotic fractures，such as changes in immune factors，abnormal chemotaxis and differentiation of mesenchymal stem cells（MSCs），decreased estrogen secretion and receptor down-regulation and decreased mechanical sensitivity，which affect the fracture healing process. Current studies have shown that by improving the phenotypic polarization of macrophages，enhancing the chemotactic osteogenic activity of MSCs，supplementing estrogen and improving the biomechanical properties of bone can remodel the balance of bone microenvironment，thereby effectively improve the bone quality. The authors explore the effect and mechanism of bone microenvironment on healing of osteoporotic fractures from the perspectives of changes in bone microenvironment and imbalance of bone microenvironment that affect fracture healing and methods of bone microenvironment reconstruction，so as to provide new ideas for clinical treatment of osteoporotic fractures.
RESUMO
Objective:To explore the effect of Bushen Huatan prescription on serum lipopolysaccharide （LPS） and Toll-like receptor 4 （TLR4）/ myeloid cell differentiation protein 88 （MyD88）/nuclear transcription factor-<italic>κ</italic>B （NF-<italic>κ</italic>B） signaling pathway in rats with ovariectomy-induced osteoporosis. Method:Sixty SPF 6-month-old female rats were randomly divided into sham operation group， model group， estradiol valerate group and Bushen Huatan prescription low， medium and high dose groups.One week after modeling by bilateral ovariectomy， 8 rats in each group were selected to receive intragastric administration.The estradiol valerate group was given 0.184 mg·kg<sup>-1</sup> by gavage， and Bushen Huatan prescription low， middle and high dose groups were given 4.7， 9.4 and 18.8 g·kg<sup>-1</sup> by gavage， sham operation group and model group were given 0.9% saline 4 mL by gavage respectively.After 12 weeks of intervention， the rats were sacrificed for detection.Serum LPS was detected by enzyme linked immunosorbent assay （ELISA）， while protein expressions of TLR4， MyD88 and phosphorylated （p）-NF-<italic>κ</italic>B p65 in bone tissue were detected by Western blot， and the mRNA expressions of TLR4， MyD88， NF-<italic>κ</italic>B p65， IL-1<italic>β</italic>， and IL-6 in bone tissue were detected by quantitative real-time polymerase chain reaction（PCR）. Result:Compared with sham operation group， the serum LPS level as well as protein expression of TLR4， MyD88， p-NF-<italic>κ</italic>B p65 and mRNA expression of TLR4， MyD88， NF-<italic>κ</italic>B p65， IL-1<italic>β</italic>， and IL-6 significantly increased in model group（<italic>P</italic><0.05）.Compared with the model group， serum LPS level， protein expression of TLR4， MyD88， and p-NF-<italic>κ</italic>B p65， mRNA levels of TLR4， MyD88， and NF-<italic>κ</italic>B p65 in bone tissues as well as downstream inflammatory factors IL-1<italic>β</italic>， IL-6 mRNA expression decreased to different degrees in estradiol valerate group and Bushen Huatan prescription high dose group（<italic>P</italic><0.05）. Conclusion:Bushen Huatan prescription can reduce serum LPS content， regulate mRNA and protein expression of TLR4， MyD88， NF-<italic>κ</italic>B p65 and p-NF-<italic>κ</italic>B p65 in TLR4/MyD88/NF-<italic>κ</italic>B pathway， and down-regulate mRNA levels of IL-1<italic>β</italic> and IL-6 in bone tissues to improve bone microstructure and inhibit the development of postmenopausal osteoporosis （PMOP）.
RESUMO
Multiple myeloma (MM) is a plasma cell malignancy characterized by the accumulation of malignant plasma cells within the bone marrow (BM). MM cells interact with the microenvironment and induce pathological modifications that in turn support the growth and survival of MM cells. The BM microenvironment consists of various extracellular matrix proteins, and cell components as haematopoietic stem cells, progenitor and precursor cells, immune cells, erythrocytes, BM stromal cells (BMSCs), BM endothelial cells, as well as osteoclasts and osteoblasts that are able to secret several growth factors for MM cells. The direct interactions of MM cells with the microenvironment and the secreted cytokines activate signalling pathways mediating growth, survival, drug resistance and the migration of MM cells as well as osteoclastogenesis and angiogenesis. In this article we underline in particular the new evidences at the basis of the interaction between MM cell and bone cells and the potential role of osteoclast and osteoblast in MM pathophysiology.
O mieloma múltiplo (MM) é uma doença maligna das células plasmáticas caracterizada pelo acúmulo de células plasmáticas na medula óssea (MO). As células do MM interagem com o microambiente e induzem modificações patológicas que, por seu turno, propiciam o crescimento e a sobrevida das células do MM. O microambiente da MO consiste de várias proteínas da matriz extracelular e de componentes hematopoéticos: células-tronco, progenitoras e precursoras, células imunes, eritrocitárias, estromais, endoteliais. Possuem também osteoclastos e osteoblastos capazes de secreção de fatores de crescimento das células do MM. A direta interação das células mielomatosas com o microambiente e a secreção de citocinas ativam cascatas sinalizadoras que mediam o crescimento, sobrevida, resistência a drogas e a migração destas células assim como a osteoclastogênese e a angiogênese. Neste artigo explicitamos novas evidências e as bases da interação das células mielomatosas e as células medulares e o provável papel dos osteoclastos e dos osteoblastos na fisiopatologia do MM.