MicroRNAs' Involvement in Osteoarthritis and the Prospects for Treatments.

Osteoarthritis (OA) is a chronic disease and its etiology is complex. With increasing OA incidence, more and more people are facing heavy financial and social burdens from the disease. Genetics-related aspects of OA pathogenesis are not well understood. Recent reports have examined the molecular mechanisms and genes related to OA. It has been realized that genetic changes in articular cartilage and bone may contribute to OA's development. Osteoclasts, osteoblasts, osteocytes, and chondrocytes in joints must express appropriate genes to achieve tissue homeostasis, and errors in this can cause OA. MicroRNAs (miRNAs) are small noncoding RNAs that have been discovered to be overarching regulators of gene expression. Their ability to repress many target genes and their target-binding specificity indicate a complex network of interactions, which is still being defined. Many studies have focused on the role of miRNAs in bone and cartilage and have identified numbers of miRNAs that play important roles in regulating bone and cartilage homeostasis. Those miRNAs may also be involved in the pathology of OA, which is the focus of this review. Future studies on the role of miRNAs in OA will provide important clues leading to a better understanding of the mechanism(s) of OA and, more particularly, to the development of therapeutic targets for OA.

[The Significance of Analysis of Soil from the Surface of Hetao Plain, Inner Mongolia with Near Infrared Spectra].

The technology of near infrared spectrum, marked by its convenience and effectiveness, which has been applied extensively in lithological analysis, is suitable for component analysis of regional geology, due to its superiority in analyzing numerous samples in a relatively short time. Since different mineral molecule peaks will show different characters when being analyzed in the near infrared spectrum, we can acquire the information about the mineral composition, water content, mineral crystallinity and etc. In this passage, the soil from the surface of Hetao Plain has been analyzed, and in this case, we can obtain the information about the mineral composition, water content, mineral crystallinity and etc. Referring the features of local environment and climate, we could surmise the source of the minerals in soil and the environment where they formed. The result not only consummates the geological characterization of Hetao area, but also has great significance revealing mechanism of soil-formation in Hetao area. The result shows that the soil from surface of Hetao Plain is mainly composed by altered minerals, such as kaolinite, smectite, ledikite, muscovite etc, and is presumed to be from acidic rock mass of the Yinshan mountains. The passage also indicates that the Yinshan mountains have great impact on the formation of the soil on Hetao Plain in the aspect of climate, for example, though the climate of inner Mongolia is continental arid climate, enough rainfall and the substantial differences in mean annual precipitation ensure the relatively moist environment in this area, and make the sediments altered adequately, proposing new aspects about exploring the mechanism of the soil-formation in Hetao area.

Application of bone marrow mesenchymal stem cells to the treatment of osteonecrosis of the femoral head.

Osteonecrosis of the femoral head (ONFH) is a type of common and refractory disease in the orthopedic clinic that is primarily caused by a partial obstruction of the blood supply to the femoral head, resulting in a series of pathological processes. Mesenchymal stem cells (MSCs) comprise a mixture of various stem cells in myeloid tissue with multipotential differentiation capacity. They can differentiate into bone cells under specific conditions and can be used to treat ONFH through cell transplantation. This review summarizes research on MSCs in the field of ONFH in recent years, reveals the inner characteristics of MSCs, describes their potential to treat osteonecrosis disease, and analyzes the existing challenges of using MSCs in clinical applications.

Bone microstructure and regional distribution of osteoblast and osteoclast activity in the osteonecrotic femoral head.

OBJECTIVE: To detect and compare the bone microstructure and osteoblast and osteoclast activity in different regions of human osteonecrotic femoral heads. METHODS: Osteonecrotic femoral heads were obtained from 10 patients (6 males, 4 females; Ficat IV) undergoing total hip arthroplasty between 2011 and 2013. The samples were divided into subchondral bone, necrotic, sclerotic, and healthy regions based on micro-computed tomography (CT) images. The bone microstructure, micromechanics, and osteoblast and osteoclast activity were assessed using micro-CT, pathology, immunohistochemistry, nanoindentation, reverse transcription polymerase chain reaction (RT-PCR), tartrate-resistant acid phosphatase staining and Western blotting. RESULTS: (1) The spatial structure of the bone trabeculae differed markedly in the various regions of the osteonecrotic femoral heads. (2) The elastic modulus and hardness of the bone trabeculae in the healthy and necrotic regions did not differ significantly (P >0.05). (3) The subchondral bone and necrotic region were positive on TRAP staining, while the other regions were negative. (4) On immunohistochemical staining, RANK and RANKL staining intensities were increased significantly in the subchondral bone and necrotic region compared with the healthy region, while RUNX2 and BMP2 staining intensities were increased significantly in the sclerotic region compared with the necrotic region. (5) OPG, RANK, RANKL, RUNX2, BMP2, and BMP7 protein levels were greater in the necrotic and sclerotic region than in subchondral bone and the healthy region. CONCLUSION: The micromechanical properties of bone trabeculae in the necrotic region did not differ significantly from the healthy region. During the progress of osteonecrosis, the bone structure changed markedly. Osteoclast activity increased in subchondral bone and the necrotic region while osteoblast activity increased in the sclerotic region. We speculate that the altered osteoblast and osteoclast activity leads to a reduction in macroscopic mechanical strength.

[XRD, FTIR and XPS analysis of oxidized particles from Dongshengmiao pyrite-polymetallic sulfide deposit, inner Mongolia].

In the present paper, characteristics of material compositions, phase structures, surface element states, and transformation mechanism of oxidized particles from Dongshengmiao pyrite-polymetallic sulfide deposit were studied using modern analytical testing technology including XRD, FTIR and XPS. The results show that the samples consist of gypsum, calcite, quartz, muscovite, goethite, organic matter, etc. Primary ore in deep oxidation zone mainly under went such processes as oxidization, hydrolysis, dehydration and carbonation. Compared to the surface oxidation zone of arid and extremely arid regions in the northwestern China, the oxidation process and oxidizing condition of the deep oxidation zone were less complex. New mineral type was also not found, and extensively developed sulfate minerals were rare to be seen. The research results can not only be applied to mineral identification of oxidized particles from this type of ore deposit but also play an important role in ore exploration, mining, mineral processing, etc.