Effect and mechanism of propranolol on promoting osteogenic differentiation and early implant osseointegration

Predictive nomogram model for severe coronary artery calcification in end-stage kidney disease patients

INTRODUCTION

The Agatston coronary artery calcification score (CACS) is an assessment index for coronary artery calcification (CAC). This study aims to explore the characteristics of CAC in end-stage kidney disease (ESKD) patients and establish a predictive model to assess the risk of severe CAC in patients.

METHODS

CACS of ESKD patients was assessed using an electrocardiogram-gated coronary computed tomography (CT) scan with the Agatston scoring method. A predictive nomogram model was established based on stepwise regression. An independent validation cohort comprised of patients with ESKD from multicentres.

RESULTS

369 ESKD patients were enrolled in the training set, and 127 patients were included in the validation set. In the training set, the patients were divided into three subgroups: no calcification (CACS = 0, n = 98), mild calcification (0 < CACS ≤ 400, n = 141) and severe calcification (CACS > 400, n = 130). Among the four coronary branches, the left anterior descending branch (LAD) accounted for the highest proportion of calcification. Stepwise regression analysis showed that age, dialysis vintage, β-receptor blocker, calcium-phosphorus product (Ca × P), and alkaline phosphatase (ALP) level were independent risk factors for severe CAC. A nomogram that predicts the risk of severe CAC in ESKD patients has been internally and externally validated, demonstrating high sensitivity and specificity.

CONCLUSION

CAC is both prevalent and severe in ESKD patients. In the four branches of the coronary arteries, LAD calcification is the most common. Our validated nomogram model, based on clinical risk factors, can help predict the risk of severe coronary calcification in ESKD patients who cannot undergo coronary CT analysis.

Regulation of bone homeostasis by traditional Chinese medicine active scaffolds and enhancement for the osteoporosis bone regeneration

ETHNOPHARMACOLOGICAL RELEVANCE

The active ingredients of traditional Chinese medicine (TCM), such as naringin (NG), Eucommiol, isopsoralen, icariin, Astragalus polysaccharides, and chondroitin sulfate, contained in Drynariae Rhizoma, Eucommiae Cortex, Psoralea corylifolia, Herba Epimedii, Astragalus radix and deer antler, are considered promising candidates for enhancing the healing of osteoporotic defects due to their outstanding bone homeostasis regulating properties. They are commonly used to activate bone repair scaffolds.

AIM OF THE REVIEW

Bone repair scaffolds are inadequate to meet the demands of osteoporotic defect healing due to the lack of regulation of bone homeostasis. Therefore, selecting bone scaffolds activated with TCM to improve the therapeutic effect of repairing osteoporotic bone defects.

MATERIALS AND METHODS

To gather information on bone scaffold activated by traditional Chinese medicine, we conducted a thorough search of several scientific databases, including Google Scholar, Web of Science, Scifinder, Baidu Scholar, PubMed, and China National Knowledge Infrastructure (CNKI).

RESULTS

This review discusses the mechanism of TCM active ingredients in regulating bone homeostasis, including stimulating bone formation and inhibiting bone resorption process and the healing mechanism of traditional bone repair scaffolds activated by them for osteoporotic defect healing.

CONCLUSION

In general, the introduction of TCM active ingredients provides a novel therapeutic approach for modulating bone homeostasis and facilitating osteoporotic defect healing, and also offers a new strategy for design of other unconventional bone defect healing materials.

Interoceptive regulation of skeletal tissue homeostasis and repair

Recent studies have determined that the nervous system can sense and respond to signals from skeletal tissue, a process known as skeletal interoception, which is crucial for maintaining bone homeostasis. The hypothalamus, located in the central nervous system (CNS), plays a key role in processing interoceptive signals and regulating bone homeostasis through the autonomic nervous system, neuropeptide release, and neuroendocrine mechanisms. These mechanisms control the differentiation of mesenchymal stem cells into osteoblasts (OBs), the activation of osteoclasts (OCs), and the functional activities of bone cells. Sensory nerves extensively innervate skeletal tissues, facilitating the transmission of interoceptive signals to the CNS. This review provides a comprehensive overview of current research on the generation and coordination of skeletal interoceptive signals by the CNS to maintain bone homeostasis and their potential role in pathological conditions. The findings expand our understanding of intersystem communication in bone biology and may have implications for developing novel therapeutic strategies for bone diseases.

Kwon R, Bain SD, Gross TS, M. Gardiner E. Beta 2 Adrenergic Receptor Selective Antagonist Enhances Mechanically Stimulated Bone Anabolism in Aged Mice

The anabolic response of aged bone to skeletal loading is typically poor. Efforts to improve mechanotransduction in aged bone have met with limited success. This study investigated whether the bone response to direct skeletal loading is improved by reducing sympathetic suppression of osteoblastic bone formation via β2AR. To test this possibility, we treated aged wild-type C57BL/6 mice with a selective β2AR antagonist, butaxamine (Butax), before each of nine bouts of cantilever bending of the right tibia. Midshaft periosteal bone formation was assessed by dynamic histomorphometry of loaded and contralateral tibias. Butax treatment did not alter osteoblast activity of contralateral tibias. Loading alone induced a modest but significant osteogenic response. However, when loading was combined with Butax pretreatment, the anabolic response was significantly elevated compared with loading preceded by saline injection. Subsequent studies in osteoblastic cultures revealed complex negative interactions between adrenergic and mechanically induced intracellular signaling. Activation of β2AR by treatment with the β1, β2-agonist isoproterenol (ISO) before fluid flow exposure diminished mechanically stimulated ERK1/2 phosphorylation in primary bone cell outgrowth cultures and AKT phosphorylation in MC3T3-E1 pre-osteoblast cultures. Expression of mechanosensitive Fos and Ptgs2 genes was enhanced with ISO treatment and reduced with flow in both MC3T3-E1 and primary cultures. Finally, co-treatment of MC3T3-E1 cells with Butax reversed these ISO effects, confirming a critical role for β2AR in these responses. In combination, these results demonstrate that selective inhibition of β2AR is sufficient to enhance the anabolic response of the aged skeleton to loading, potentially via direct effects upon osteoblasts. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The Role of Sympathetic Nerves in Osteoporosis: A Narrative Review

Osteoporosis, a systemic bone disease, is characterized by decreased bone density due to various reasons, destructed bone microstructure, and increased bone fragility. The incidence of osteoporosis is very high among the elderly, and patients with osteoporosis are prone to suffer from spine fractures and hip fractures, which cause great harm to patients. Meanwhile, osteoporosis is mainly treated with anti-osteoporosis drugs that have side effects. Therefore, the development of new treatment modalities has a significant clinical impact. Sympathetic nerves play an important role in various physiological activities and the regulation of osteoporosis as well. Therefore, the role of sympathetic nerves in osteoporosis was reviewed, aiming to provide information for future targeting of sympathetic nerves in osteoporosis.

Thioacetamide promotes osteoclast transformation of bone marrow macrophages by influencing PI3K/AKT pathways

Background

Osteoclast cell increase is a major risk factor for osteoporosis and degenerative bone and joint diseases. At present, RANKL and M-CSF are commonly used to induce osteoclastogenesis. Thioacetamide (TAA) can lead to many types of liver and kidney damage, but less attention has been paid to the association of TAA with bone damage. In this work, we investigated the effects of TAA on the osteoclastogenesis and differentiation of bone marrow macrophages (BMMs).

Methods

BMMs of SD rat suckling mice were taken for primary culture. CCK-8 was used to detect the toxic effects of TAA on BMMs, and flow cytometry was used to detect the effects of TAA on the cell cycle, cell viability, apoptosis and intracytoplasmic Ca2+ concentration of BMMs. TRAP staining was used to detect the effect of RANKL and M-CSF and TAA on osteoclast differentiation of BMMs. Western Blot was used to detect the expression level of PI3K/AKT pathway and osteoclast-specific proteins (TRAP and cathepsin K).

Results

The results suggested that TAA inhibited the proliferation of BMMs, while enhancing osteoclastogenesis at 0.5 mg/mL and 1 mg/mL as assayed by TRAP staining. Exposed to TAA, BMMs could differentiate into osteoclast-like cells with overexpression of cathepsin K and TRAP proteins. Western blot results showed that TAA can activate the expression levels of P-PI3K, P-AKT, P-P38, and P-JNK, accompanied by apoptosis of BMMs and increase in intracellular Ca2+.

Conclusion

TAA may induce osteoclast formation in BMMs by activating the expression of PI3K/AKT pathway proteins, which is comparable to the classic osteoclast differentiation inducer RANKL and M-CSF. This suggests that we may find a cheap osteoclast inducer.