Relationship between osteoid formation and iron deposition induced by chronic cadmium exposure in ovariectomized rats

Astaxanthin prevents bone loss in osteoporotic rats with palmitic acid through suppressing oxidative stress

OBJECTIVES

The study aimed to assess the role of Astaxanthin (ATX) in palmitic acid(PA) -induced bone loss in Ovariectomized(OVX) rats.

METHODS

In the OVX rat model, we observed that PA affects bone metabolism and accelerates bone loss. Additionally, treatment with ATX was able to suppress the deleterious effects of PA and a simultaneous decrease in serum MDA levels and an increase in SOD was observed.

RESULTS

In addition, rats treated with ATX were observed to have significantly increased bone mass and elevated activity of SIRT1 and SOD2 in bone tissue. When MC3T3-E1 and RAW264.7 cells induced osteoblast and osteoclast differentiation, the ATX intervention was able to significantly restore the restriction of osteogenic differentiation and the up-regulation of osteoclast differentiation with PA therapy. Furthermore, we confirm that PA damage to cells is caused by increased oxidative stress, and that ATX can target and modulate the activity of SIRT1 to regulate the levels of oxidative stress in cells.

CONCLUSION

Summarizing, ATX may inhibit PA-induced bone loss through its antioxidant properties via the SIRT1 signaling pathway.

Sodium butyrate protect bone mass in lipopolysaccharide-treated rats by reducing oxidative stress and inflammatory

OBJECTIVE

The study will be to observe the effect of Sodium butyrate (NaB) on bone loss in lipopolysaccharide (LPS)-treated rats.

METHODS

In the rat model, we observed that changes in the expression of oxidative stress regulators, inflammatory markers and target genes were measured by immunofluorescence and RT-PCR after treatment. Changes in viability and osteogenesis of MC3T3-E1, osteoclast differentiation in RAW264.7 cells in the presence of LPS were evaluated using CCK-8, ALP staining, RES staining, and TRAP staining.

RESULTS

In vitro experiments have shown that LPS-induced inhibition of JC-1, SIRT1, GPX1 and SOD2 is associated with increased levels of inflammation and oxidative stress. In addition, NaB has been found to suppress oxidative stress, inflammation and Mito SOX, promote osteogenic differentiation, and inhibit osteoclast differentiation. In addition, NaB significantly promoted SITR1 expression, repaired impaired bone metabolism, and improved bone strength and bone mineral density.

CONCLUSION

Given all this experimental evidence, the results strongly suggest that NaB can restore osteogenic activity in the presence of LPS by reducing intracellular ROS, inhibiting osteoclast differentiation and reducing bone loss in LPS-treated rat models.

Osteomalacia in Adults: A Practical Insight for Clinicians

The term osteomalacia (OM) refers to a series of processes characterized by altered mineralization of the skeleton, which can be caused by various disorders of mineral metabolism. OM can be genetically determined or occur due to acquired disorders, among which the nutritional origin is particularly relevant, due to its wide epidemiological extension and its nature as a preventable disease. Among the hereditary diseases associated with OM, the most relevant is X-linked hypophosphatemia (XLH), which manifests in childhood, although its consequences persist into adulthood where it can acquire specific clinical characteristics, and, although rare, there are XLH cases that reach the third or fourth decade of life without a diagnosis. Some forms of OM present very subtle initial manifestations which cause both considerable diagnosis and treatment delay. On occasions, the presence of osteopenia and fragility fractures leads to an erroneous diagnosis of osteoporosis, which may imply the prescription of antiresorptive drugs (i.e., bisphosphonates or denosumab) with catastrophic consequences for OM bone. On the other hand, some radiological features of OM can be confused with those of axial spondyloarthritis and lead to erroneous diagnoses. The current prevalence of OM is not known and is very likely that its incidence is much higher than previously thought. Moreover, OM explains part of the therapeutic failures that occur in patients diagnosed with other bone diseases. Therefore, it is essential that clinicians who treat adult skeletal diseases take into account the considerations provided in this practical review when focusing on the diagnosis and treatment of their patients with bone diseases.

Deferoxamine/magnesium modified β-tricalcium phosphate promotes the bone regeneration in osteoporotic rats

Recently, Deferoxamine (DFO) and magnesium (Mg) have been identified as critical factors for angiogenesis and bone formation. However, in current research studies, there is a lack of focus on whether DFO plus Mg can affect the regeneration of β-tricalcium phosphate (β-TCP) in osteoporosis and through what biological mechanisms. Therefore, the present work was aimed to preparation and evaluate the effect of Deferoxamine/magnesium modified β-tricalcium phosphate promotes (DFO/Mg-TCP) in ovariectomized rats model and preliminary exploration of possible mechanisms. The MC3T3-E1 cells were co-cultured with the exudate of DFO/Mg-TCP and induced to osteogenesis, and the cell viability, osteogenic activity were observed by Cell Counting Kit-8(CCK-8), Alkaline Phosphatase (ALP) staining, Alizarin Red Staining (RES) and Western Blot. In vitro experiments, CCK-8, ALP and ARS staining results show that the mineralization and osteogenic activity of MC3T3-E1increased significantly after intervention by DFO/Mg-TCP, as well as a higher levels of protein expressions including VEGF, OC, Runx-2 and HIF-1α. In vivo experiment, Micro-CT and Histological analysis evaluation show that DFO/Mg-TCP treatment presented the stronger effect on bone regeneration, bone mineralization and biomaterial degradation, when compared with OVX+Mg-TCP group and OVX+TCP group, as well as a higher VEGF, OC, Runx-2 and HIF-1α gene expression. The present study indicates that treatment with DFO/Mg-TCP was associated with increased regeneration by enhancing the function of osteoblasts in an OVX rat.

Local treatment with Sema3a could promote the osseointegration of hydroxyapatite coated titanium rod in diabetic rats

Recently, semaphorin 3A (Sema3A) has been identified as a critical gene for osteogenic differentiation of mesenchymal stem cells and increases osteoblastic bone formation. However, in current research studies, there is a lack of focus on whether Sema3a can affect the osseointegration of titanium rods in diabetes and through what biological mechanisms. Therefore, the present work was aimed to evaluate the effect of local administration with Sema3A on hydroxyapatite coated titanium rod osseointegration in diabetic rat model and preliminary exploration of possible mechanisms. The MC3T3-E1 cells were co-cultured with Sema3A and high glucose and induced to osteogenesis, and the cell viability, osteogenic activity was observed by Cell Counting Kit-8(CCK-8), Alkaline Phosphatase staining, Alizarin Red Staining, and Western Blot. In vitro experiments, CCK-8, ALP, and ARS staining results show that the mineralization and osteogenic activity of MC3T3-E1increased significantly after intervention by Sema3A, as well as a higher levels of protein expressions including Runt-Related Transcription Factor 2, silent mating type information regulation 2 homolog-1(SIRT1), catalase (CAT), superoxide dismutase 1 (SOD1), and superoxide dismutase 2 (SOD2). In vivo experiment, a better stability and osseointegration of the titanium rod were observed after treatment with Sema3A, as well as a higher SOD1, SOD2, CAT, and SIRT1 gene expression. The present study indicates that local treatment with Sema3A was associated with increased osseointegration of titanium rod by reducing the oxidative stress of osteoblasts and enhancing the function of osteoblasts in a diabetic rat.