Risk of atypical femoral fractures and osteonecrosis of the jaw associated with alendronate use compared with other oral bisphosphonates

Benefits and Implications of Resveratrol Supplementation on Microbiota Modulations: A Systematic Review of the Literature

Resveratrol is a polyphenol that has been shown to possess many applications in different fields of medicine. This systematic review has drawn attention to the axis between resveratrol and human microbiota, which plays a key role in maintaining an adequate immune response that can lead to different diseases when compromised. Resveratrol can also be an asset in new technologies, such as gene therapy. PubMed, Cochrane Library, Scopus, Web of Science, and Google Scholar were searched to find papers that matched our topic dating from 1 January 2017 up to 18 January 2022, with English-language restriction using the following Boolean keywords: (“resveratrol” AND “microbio*”). Eighteen studies were included as relevant papers matching the purpose of our investigation. Immune response, prevention of thrombotic complications, microbiota, gene therapy, and bone regeneration were retrieved as the main topics. The analyzed studies mostly involved resveratrol supplementation and its effects on human microbiota by trials in vitro, in vivo, and ex vivo. The beneficial activity of resveratrol is evident by analyzing the changes in the host’s genetic expression and the gastrointestinal microbial community with its administration. The possibility of identifying individual microbial families may allow to tailor therapeutic plans with targeted polyphenolic diets when associated with microbial dysbiosis, such as inflammatory diseases of the gastrointestinal tract, degenerative diseases, tumors, obesity, diabetes, bone tissue regeneration, and metabolic syndrome.

In Silico Network Analysis of Ingredients of Cornus officinalis in Osteoporosis

BACKGROUND Cornus officinalis (CO), also known as 'Shanzhuyu', is one of the most common traditional Chinese herbs used against osteoporosis. Although previous studies have found that CO has beneficial effects in alleviating osteoporosis, its mechanisms remain unclear. MATERIAL AND METHODS In this study, we applied system bioinformatic approaches to investigate the possible therapeutic mechanisms of CO against osteoporosis. We collected the active ingredients of CO and their targets from the TCMSP, BATMAN-TCM, and ETCM databases. Next, we obtained the osteoporosis targets from differentially expressed mRNAs from the Gene Expression Omnibus (GEO) gene series (GSE35958). Next, the shared genes of the CO pharmacological targets and osteoporosis-related targets were selected to construct the protein-protein interaction network, based on the results from the STRING database. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out by using the clusterProfiler package in R software. RESULTS In all, there were 58 unique CO compounds and 518 therapeutic targets. Based on the GO and KEGG enrichment results of 98 common genes, we selected the top 25 terms, based on the terms' P values. We found that the anti-osteoporotic effect of CO may mostly involve the regulation of calcium metabolism and reactive oxygen species, and the estrogen signaling pathway and osteoclast differentiation pathway. CONCLUSIONS We found the possible mechanisms of CO in treating osteoporosis may be based on multiple targets and pathways. We also provided a theoretical basis and promising direction for investigating the exact anti-osteoporotic mechanisms of CO.

Novel applications of platelet concentrates in tissue regeneration (Review)

Numerous studies have explored the suitability of biocompatible materials in regenerative medicine. Platelet concentrates are derived from centrifuged blood and are named according to their biological characteristics, such as platelet-rich plasma, platelet-rich fibrin and concentrated growth factor. Platelet concentrates have gained considerable attention in soft and hard tissue engineering. Indeed, multiple components of autologous platelet concentrates, such as growth factors, fibrin matrix and platelets, serve essential roles in wound healing. Current studies are focused on cutting-edge strategies to meet the requirements for tissue restoration by improving the properties of autologous platelet concentrates. In the present review, applications of platelet concentrates for tissue engineering are discussed, presenting a selection of recent advances and novel protocols. In addition, several aspects of these strategies, such as the advantages of lyophilized platelet concentrates and the combination of platelet concentrates with biomaterials, stem cells or drugs are discussed. The present review aims to summarize novel strategies using platelet concentrates to improve the outcomes of wound healing.

Deciphering the Underlying Mechanism of Eucommiae Cortex against Osteoporotic Fracture by Network Pharmacology

Background

Du Zhong (DZ), or Eucommiae Cortex, a traditional Chinese herbal medicine, has been used to treat osteoporosis. Although it has been reported that DZ can improve bone mass in ovariectomized rats, its pharmacological mechanisms in treating osteoporotic fractures (OPF) remain unclear.

Methods

In this study, we used a network pharmacological manner to explore its potential complicated mechanism in treating OPF. We obtained DZ compounds from TCMSP and BATMAN-TCM databases and collected potential targets of these compounds through target fishing based on TCMSP and BATMAN-TCM databases. Next, we collected the OPF targets by using CTD, GeneCards, OMIM, HPO, and GenCLiP 3 databases. And then the overlapping genes between DZ potential targets and OPF targets were used to build up the protein-protein interaction (PPI) network and to analyze their interactions and find out the big hub genes in this network. Subsequently, clusterProfiler package in R language was utilized to conduct the enrichment of Gene Ontology biological process and KEGG pathways.

Results

There were totally 93 active compounds and 916 related targets in DZ. After the enrichment analysis, we collected top 25 cellular biological processes and top 25 pathways based on the adjusted P value and found that the DZ anti-OPF effect was mainly associated with the regulation of ROS and inflammatory response. Furthermore, 64 hub genes in PPI network, such as MAPK1 (degree = 41), SRC (degree = 39), PIK3R1 (degree = 36), VEGFA (degree = 31), TP53 (degree = 29), EGFR (degree = 29), JUN (degree = 29), AGT (degree = 29), MAPK1, SRC, PIK3R1, VEGFA, and TP53, were considered as potential therapeutic targets, implying the underlying mechanisms of DZ acting on OPF.

Conclusion

We investigated the possible therapeutic mechanisms of DZ from a systemic perspective. These key targets and pathways provided promising directions for the future research to reveal the exact regulating mechanisms of DZ in treating OPF.

Bone-Targeting Liposome-Encapsulated Salvianic Acid A Improves Nonunion Healing Through the Regulation of HDAC3-Mediated Endochondral Ossification

AIM

Nonunion is a major complication in fracture repair and remains a challenge in orthopaedics and trauma surgery. In this study, we aimed to evaluate the effectiveness of treatment of nonunion with a large radial defect using a bone-targeting liposome-encapsulated salvianic acid A (SAA-BTL)-incorporated collagen sponge and further elucidate whether the effects were closely related to histone deacetylase 3 (HDAC 3)-mediated endochondral ossification in nonunion healing process.

METHODS

Fifteen New Zealand female rabbits were randomly divided into three groups. Segmental radius critical size defects (15 mm) were created via surgery on both the forelimbs of the rabbits. The SAA-BTL/SAA/saline-incorporated collagen sponges were implanted into the defects in the three groups, respectively, for four weeks of treatment. X-ray imaging, micro-computed tomography (CT) analysis, histology, and immunofluorescence analysis (HDAC3, collagen II, VEGFA, and osteocalcin) were performed to determine the effects of the treatments. In addition, a short interfering RNA was applied to induce HDAC3 knockdown in the chondrogenic cell line ATDC5 to investigate the roles of HDAC3 and SAA intervention in endochondral ossification in nonunion healing.

RESULTS

X-ray imaging and micro-CT results revealed that SAA-BTL-incorporated collagen sponges significantly stimulated bone formation in the nonunion defect rabbit model. Furthermore, immunofluorescence double staining and histology analysis confirmed that SAA-BTL significantly increased the expression of P-HDAC3, collagen II, RUNX2, VEGFA, and osteocalcin in vivo; accelerated endochondral ossification turnover from cartilage to bone; and promoted long bone healing of nonunion defects. ATDC5 cells knocked down for HDAC3 showed significantly decreased expression of HDAC3, which resulted in reduced expression of chondrogenesis, osteogenesis, and angiogenesis biomarker genes (Sox9, Col10a1, VEGFA, RUNX2, and Col1a1), and increased expression of extracellular matrix degradation marker (MMP13). SAA treatment reversed these effects in the HDAC3 knockdown cell model.

CONCLUSION

SAA-BTL can improve nonunion healing through the regulation of HDAC3-mediated endochondral ossification.

Novel transplant of combined platelet-rich fibrin Releasate and bone marrow stem cells prevent bone loss in Ovariectomized osteoporotic mice

BACKGROUND

Osteoporosis is a metabolic bone disorder characterized by deterioration in the quantity and quality of bone tissue, with a consequent increase susceptibility to fracture.

METHODS

In this study, we sought to determine the efficacy of platelet-rich fibrin releasates (PRFr) in augmenting the therapeutic effects of stem cell-based therapy in treating osteoporotic bone disorder. An osteoporosis mouse model was established through bilateral ovariectomy on 12-week-old female ICR (Institute of Cancer Research) mice. Eight weeks postoperatively, the ovariectomized (OVX) mice were left untreated (control) or injected with PRFr, bone marrow stem cells (BMSCs), or the combination of BMSCs and PRFr. Two different injection (single versus quadruple) dosages were tested to investigate the accumulative effects of BMSCS and PRFr on bone quality. Eight weeks after injection, the changes in tibial microstructural profiles included the percentage of bone volume versus total tissue volume (BV/TV, %), bone mineral density (BMD, g/cm3), trabecular number (Tb.N, number/mm), and trabecular separation (Tb.Sp, mm) and bony histology were analyzed.

RESULTS

Postmenopausal osteoporosis model was successfully established in OVX mice, evidenced by reduced BMD, decreased BV/TV, lower Tb.N but increased Tb.Sp. Eight weeks after injection, there was no significant change to BMD and bone trabeculae could be detected in mice that received single-injection regimen. In contrast, in mice which received 4 doses of combined PRFr and BMSCs, the BMD, BV/TV, and TB.N increased, and the TB.Sp decreased significantly compared to untreated OVX mice. Moreover, the histological analysis showed the trabecular spacing become narrower in OVX-mice treated with quadruple injection of BMSCs and combined PRFr and BMSCs than untreated control.

CONCLUSION

The systemic administration of combined BMSCs and PRFr protected against OVX-induced bone mass loss in mice. Moreover, the improvement of bony profile scores in quadruple-injection group is better than the single-injection group, probably through the increase in effect size of cells and growth factors. Our data also revealed the combination therapy of BMSCs and PRFr has better effect in enhancing osteogenesis, which may provide insight for the development of a novel therapeutic strategy in osteoporosis treatment.

A Genome-Wide Association Study of Bisphosphonate-Associated Atypical Femoral Fracture

Atypical femoral fracture is a well-documented adverse reaction to bisphosphonates. It is strongly related to duration of bisphosphonate use, and the risk declines rapidly after drug withdrawal. The mechanism behind bisphosphonate-associated atypical femoral fracture is unclear, but a genetic predisposition has been suggested. With the aim to identify common genetic variants that could be used for preemptive genetic testing, we performed a genome-wide association study. Cases were recruited mainly through reports of adverse drug reactions sent to the Swedish Medical Products Agency on a nation-wide basis. We compared atypical femoral fracture cases (n = 51) with population-based controls (n = 4891), and to reduce the possibility of confounding by indication, we also compared with bisphosphonate-treated controls without a current diagnosis of cancer (n = 324). The total number of single-nucleotide polymorphisms after imputation was 7,585,874. A genome-wide significance threshold of p < 5 × 10^-8 was used to correct for multiple testing. In addition, we performed candidate gene analyses for a panel of 29 genes previously implicated in atypical femoral fractures (significance threshold of p < 5.7 × 10^-6). Compared with population controls, bisphosphonate-associated atypical femoral fracture was associated with four isolated, uncommon single-nucleotide polymorphisms. When cases were compared with bisphosphonate-treated controls, no statistically significant genome-wide association remained. We conclude that the detected associations were either false positives or related to the underlying disease, i.e., treatment indication. Furthermore, there was no significant association with single-nucleotide polymorphisms in the 29 candidate genes. In conclusion, this study found no evidence of a common genetic predisposition for bisphosphonate-associated atypical femoral fracture. Further studies of larger sample size to identify possible weakly associated genetic traits, as well as whole exome or whole-genome sequencing studies to identify possible rare genetic variation conferring a risk are warranted.

Beneficial Effects of Concentrated Growth Factors and Resveratrol on Human Osteoblasts In Vitro Treated with Bisphosphonates

Bisphosphonates are primary pharmacological agents against osteoclast-mediated bone loss and widely used in the clinical practice for prevention and treatment of a variety of skeletal conditions, such as low bone density and osteogenesis imperfecta, and pathologies, such as osteoporosis, malignancies metastatic to bone, Paget disease of bone, multiple myeloma, and hypercalcemia of malignancy. However, long-term bisphosphonate treatment is associated with pathologic conditions including osteonecrosis of the jaw, named BRONJ, which impaired bone regeneration process. Clinical management of BRONJ is controversy and one recent approach is the use of platelet concentrates, such as Concentrated Growth Factors, alone or together with biomaterials or antioxidants molecules, such as resveratrol. The aim of the present study was to investigate the in vitro effects of Concentrated Growth Factors and/or resveratrol on the proliferation and differentiation of human osteoblasts, treated or not with bisphosphonates. Human osteoblasts were stimulated for 3 days in complete medium and for 21 days in mineralization medium. At the end of the experimental period, the in vitro effect on osteoblast proliferation and differentiation was evaluated using different techniques such as MTT, ELISA for the quantification/detection of osteoprotegerin and bone morphogenetic protein-2, immunohistochemistry for sirtuin 1 and collagen type I, and the Alizarin Red S staining for the rate of mineralization. Results obtained showed that Concentrated Growth Factors and/or resveratrol significantly increased osteoblast proliferation and differentiation and that the cotreatment with Concentrated Growth Factors and resveratrol had a protective role on osteoblasts treated with bisphosphonates. In conclusion, these data suggest that this approach could be promised in the clinical management of BRONJ.

Hydrogen Sulfide: A Worthwhile Tool in the Design of New Multitarget Drugs

H₂S is a gaseous molecule able to trigger a plethora of central physiological and pharmacological effects as antioxidant, pro- and anti-inflammatory, pro- and anti-nociceptive, neuromodulator, and cytoprotective. The polypharmacology of H₂S depends on the wide variety of targets implicated, but, despite the efforts, the mechanisms of action that should clarify its activity are still not completely unrevealed. Nevertheless, many attempts to exploit the multifaceted profile of this molecule have already been accomplished and many chemical entities containing an H₂S-releasing pharmacophore have been synthetized. Here we discuss recent investigations on multitarget molecules able to release H₂S, with a particular focus on the combinations of "native drug" with moieties structurally able to release H₂S and their applications as therapeutic tools in bone disease, gastrointestinal system and neurodegenerative disorders.

A Novel H2S-releasing Amino-Bisphosphonate which combines bone anti-catabolic and anabolic functions

Bisphosphonates (BPs) are the first-line treatment of bone loss resulting from various pathological conditions. Due to their high affinity to bone they have been used to develop conjugates with pro-anabolic or anti-catabolic drugs. We recently demontrated that hydrogen sulfide (H₂S), promotes osteogenesis and inhibits osteoclast differentiation. Here we developed an innovative molecule, named DM-22, obtained from the combination of alendronate (AL) and the H₂S-releasing moiety aryl-isothiocyanate. DM-22 and AL were assayed in vitro in the concentration range 1-33 μM for effects on viability and function of human osteoclasts (h-OCs) and mesenchymal stromal cells (h-MSCs) undergoing osteogenic differentiation. Amperometric measures revealed that DM-22 releases H₂S at a slow rate with a thiol-dependent mechanism. DM-22 significantly inhibited h-OCs differentiation and function, maintaining a residual h-OCs viability even at the high dose of 33 μM. Contrary to AL, in h-MSCs DM-22 did not induce cytotoxicity as revealed by LDH assay, significantly stimulated mineralization as measured by Alizarin Red staining and increased mRNA expression of Collagen I as compared to control cultures. In conclusion, DM-22 is a new BP which inhibits h-OCs function and stimulate osteogenic differentiation of h-MSCs, without cytotoxicity. DM-22 is an ideal candidate for a novel family of osteoanabolic drugs.

Bisphosphonates in the treatment of osteoporosis: a review of skeletal safety concerns

The use of bisphosphonates in treatment of osteoporosis declined significantly over the past decade. There is currently great concern, among patients and physicians, about two potential skeletal adverse effects associated with bisphosphonates- jaw osteonecrosis and atypical femur fractures. This has become a major public health issue since untreated osteoporosis carries a significant burden in terms of fracture-related morbidity and mortality, and bisphosphonates, considered first-line therapy for osteoporosis, have established efficacy in fracture and mortality reduction. Areas covered: In this review we discuss current literature on osteonecrosis of the jaw and atypical femur fractures in patients with osteoporosis treated with bisphosphonates, including case definition, pathogenesis, epidemiology, risk factors, clinical presentation, management and prevention. We conducted a literature search using PubMed and PubMed Central, using the search terms 'bisphosphonates', 'osteonecrosis of the jaw', and 'atypical fractures'. We selected relevant articles including meta-analyses, clinical trials, observational studies, and major society guidelines published between 2010 and 2016, to be included in this review. A few articles published prior to 2010 were also included as references. Expert commentary: The rare skeletal side effects of bisphosphonates should not preclude their use in patients with osteoporosis and high fracture risk, as benefits significantly outweigh the risks.

Sclerostin, an emerging therapeutic target for treating osteoporosis and osteoporotic fracture: A general review

Osteoporosis and its associated fracture risk has become one of the major health burdens in our aging population. Currently, bisphosphonate, one of the most popular antiresorptive drugs, is used widely to treat osteoporosis but so far still no consensus has been reached for its application in treatment of osteoporotic fractures. However, in old patients, boosting new bone formation and its remodelling is essential for bone healing in age-related osteoporosis and osteoporotic fractures. Sclerostin, an inhibitor of the Wnt/β-catenin signalling pathway that regulates bone growth, has become an attractive therapeutic target for treating osteoporosis. In this review, we summarize the recent findings of sclerostin and its potential as an effective drug target for treating both osteoporosis and osteoporotic fractures.