Bone最新文献

Postmenopausal osteoporosis is a type of bone disease with bone loss and deterioration of skeletal function that occurs in women after menopause. Studies have found that early-life exercise can reduce the risk of fractures and decrease the occurrence of osteoporosis, making it a promising approach for preventing and reversing bone loss. In this study, to identify the optimal forms of exercise during early life to optimize bone health and provide suggestions for promoting bone health through exercise training during early life, we conducted different forms of exercise interventions including ladder climbing, treadmill running, combined training, and whole-body vibration (WBV) on adolescent mice for 8 weeks and observed the accumulation of bone mass and arrangement of bone microstructure in adult mice. After removing the ovaries bilaterally, the mice were resting for 22 weeks to simulate the bone loss condition observed in postmenopausal women. We examined the resistance of the bone microstructure to degradation in response to exercise during early life and characterized the specific effects of different forms of exercise on countering bone microstructure deterioration. Our findings demonstrate that early-life exercise exerts long-term beneficial effects on bone health. All four forms of early-life exercise can delay bone loss due to decreased estrogen and improve the bone microstructure to varying degrees, with resistance and vibration training demonstrating superior protective benefits.

Bone tissue engineering (BTE) has emerged as a promising approach to address large bone defects caused by trauma, infections, congenital malformations, and tumors. This review focuses on scaffold design, cell sources, growth factors, and vascularization strategies, highlighting their roles in developing effective treatments. We explore the complexities of balancing mechanical properties, porosity, and biocompatibility in scaffold materials, alongside optimizing mesenchymal stem cell delivery methods. The critical role of growth factors in bone regeneration and the need for controlled release systems are discussed. Vascularization remains a significant hurdle, with strategies such as angiogenic factors, co-culture systems, and bioprinting under investigation. Mechanical challenges, tissue responses, and inflammation management are examined, alongside gene therapy's potential for enhancing osteogenesis and angiogenesis via both viral and non-viral delivery methods. The review emphasizes the impact of patient-specific factors on bone healing outcomes and the importance of personalized approaches. Future directions are described, emphasizing the necessity of interdisciplinary cooperation to advance the field of BTE and convert laboratory results into clinically feasible solutions.

Excessive osteoclast activity could cause skeletal diseases including osteoporosis. Additionally, autophagy plays an initial role in osteoclast differentiation and function. Ginkgolide B (GB), a key compound in Ginkgo biloba, improves bone mass and suppresses mature osteoclast formation in vitro. This study examines the role of GB role in regulating osteoclast formation via autophagy. Using murine bone marrow-derived macrophages in vitro, we explored GB's effects on autophagy and osteoclast formation. We also assessed bone loss prevention in an ovariectomized (OVX) mouse model using GB combined with an autophagy inhibitor. Tartrate-resistant acid phosphatase staining was used to observe osteoclast formation. Autophagy-related proteins and intracellular microtubule associated protein 1 light chain 3 beta puncta were observed using western blotting and immunofluorescence. The impact of GB on OVX mice was evaluated using micro-computed tomography and hematoxylin and eosin staining. GB directly promoted autophagy in osteoclast precursors (OCPs), but inhibited osteoclast differentiation by reducing receptor activator of nuclear factor kappa B ligand (RANKL)-induced autophagy. GB inhibits the phosphorylation of RANKL downstream signaling pathways, such as Jun N-terminal kinase (JNK), p38, and extracellular signal-regulated kinase (ERK). Anisomycin (ANI), a JNK activator, reversed GB's inhibitory effects on RANKL-induced autophagy and osteoclastogenesis. Inhibiting autophagy using 3-Methyladenine (3-MA) or small interfering RNA significantly suppressed osteoclast differentiation both in vitro and in vivo. Our findings suggested that GB inhibits osteoclast formation by decreasing JNK phosphorylation and autophagy under RANKL stimulation. Interestingly, GB also directly promotes autophagy in OCPs. Thus, GB markedly reduces osteoclast differentiation and prevents bone loss, with its anti-osteoclastogenesis effect being enhanced by 3-MA. Accordingly, inhibiting GB-induced direct autophagy could further increase its therapeutic effect on bone disease resulting from excessive osteoclast activity.

Introduction: The exact mechanisms of bone remodelling after scaphoid fractures are not fully understood. Blood supply may lead to delayed consolidation and non-unions as challenging long-term problems. The aim of this study was to follow-up the microstructure during the scaphoid bone remodelling process using High Resolution peripheral Quantitative Computed Tomography (HR-pQCT) and compare the results with clinical and laboratory data.

Patients and methods: In this monocentric, prospective, controlled, clinical trial 39 patients with an unilateral conservatively treated scaphoid fracture at the level of the waist or the distal pole were followed up over one year (2, 4, 6, 12, 26 and 52 weeks after trauma). Fracture healing was monitored by clinical examination, blood bone remodelling markers and HR-pQCT.

Results: The HR-pQCT showed significant changes in trabecular number, trabecular thickness, trabecular separation and bone mineral density until the 52 week follow-up. Complete bony consolidation on HR-pQCT was evident in half of the fractures at 12 weeks and in all fractures at 52 weeks after trauma. None of the patients developed a non-union. Carboxy-terminal collagen crosslinks as resorption marker showed significant changes until the 52 week follow-up.

Conclusion: This study shows detailed clinical, laboratory and radiologic changes during follow-up of uncomplicated fracture healing of conservative scaphoids. Bony consolidation is highly variable and can take up to one year after fracture. Larger studies are warranted, as HR-pQCT might provide detailed microstructural information to better predict fracture healing processes, thus acting as a high-resolution and low-radiation alternative to standard conventional CT.

Aging leads to progressive bone loss, which is associated with impaired bone and marrow perfusion. The purpose of this study was to determine whether chronic exercise training enhances blood flow to the femur at rest and during exercise, and elucidate whether putative changes in training-induced bone perfusion are associated with alterations in the intrinsic vasomotor properties of the femoral principal nutrient artery (PNA) in old age. Young (4-6 mo old) and old (20-22 mo old) male Fischer-344 rats were either treadmill exercise trained (ET) or remained sedentary (SED). Regional blood flow to the femur was assessed at rest and during treadmill exercise. Endothelium-dependent (acetylcholine, ACh) and -independent (Dea-NONOate) vasodilator, and vasoconstrictor (phenylephrine (PE), KCl and myogenic) responses of femoral PNAs were determined. Exercise training led to higher blood flow to distal metaphysis and epiphysis in old rats at rest, and old ET rats showed greater regional blood flow during exercise compared to old SED rats. The increased blood flow to the proximal and distal metaphysis and epiphysis were also higher in old ET rats than that in young ET rats. Exercise training enhanced the vasodilator response to ACh, corresponding to increased eNOS expression in femoral PNAs from both young and old rats. Aging did not alter PE- or KCl-induced vasoconstriction, whereas myogenic responses were impaired. Exercise training enhanced vasoconstrictor responses to PE in old rats but had no effect on KCl or myogenic responses in either group. These data demonstrate that exercise training enhances both regional bone and marrow blood flow and vasodilator responses, which are impaired in the femora of old SED rats.

Glyconutrients help in the body's cell communication. Glyconutrients and synbiotics are promising options for improving immune function. Therefore, we hypothesized that combining synbiotics and glyconutrients will enhance pig nutrient utilization. 150 pigs (Landrace × Yorkshire × Duroc), initially weighing 58.85 ± 3.30 kg of live body weight (BW) were utilized to determine the effects of synbiotics-glyconutrients (SGN) on the pigs' performance, feed efficiency, gas emission, pork traits, and composition of fatty acids. The pigs were matched by BW and sex and chosen at random to 1 of 3 diet treatments: control = Basal diet; TRT1 = Basal diet + SGN 0.15%; TRT2 = Basal diet + SGN 0.30%%. The trials were conducted in two phases (weeks 1-5 and weeks 5-10). The average daily gain was increased in pigs fed a basal diet with SGN (p = 0.036) in weeks 5-10. However, the apparent total tract digestibility of dry matter, nitrogen, and gross energy did not differ among the treatments (p > 0.05). Dietary treatments had no effect on NH₃, H₂S, methyl mercaptans, acetic acids, and CO₂ emissions (p > 0.05). Improvement in drip loss on day 7 (p = 0.053) and tendency in the cooking loss were observed (p = 0.070) in a group fed basal diets and SGN at 0.30% inclusion level. The group supplemented with 0.30% of SGN had higher levels of palmitoleic acid (C16:1), margaric acid (C17:0), omega-3 fatty acid, omega-6 fatty acid, and ω-6: ω-3 ratio (p = 0.034, 0.020, 0.025, 0.007, and 0.003, respectively) in the fat of finishing pigs. Furthermore, group supplemented with 0.30% of SGN improved margaric acid (C17:0), linoleic acid (C18:2n6c), arachidic acid (C20:0), omega 6 fatty acid, omega-6 to omega-3 ratio, unsaturated fatty acid, and monounsaturated fatty acid (p = 0.037, 0.05, 0.0142, 0.036, 0.033, 0.020, and 0.045, respectively) in the lean tissues of finishing pigs compared to pigs fed with the control diets. In conclusion, the combination of probiotics, prebiotics, and glyconutrients led to higher average daily gain, improved the quality of pork, and more favorable fatty acid composition. Therefore, these results contributed to a better understanding of the potential of SGN combinations as a feed additive for pigs.