Bone Anabolic Agent Research Articles

Abaloparatide Exerts Bone Anabolic Effects with Less Stimulation of Bone Resorption-Related Factors: A Comparison with Teriparatide

Abaloparatide (ABL) is a novel synthetic peptide analog of parathyroid hormone-related protein. In previous reports, intermittent ABL administration showed robust bone mineral density (BMD) increase and reduced the incidence of fractures in patients with osteoporosis, while its calcemic effect was reduced, as compared with teriparatide (TPTD), a parathyroid hormone N-terminal fragment. The present study aimed to elucidate the effects of ABL on bone anabolism and bone turnover as compared with TPTD. In ovariectomized (OVX) rats, ABL increased the bone strength and BMD of lumbar spine by intermittent administration similar to TPTD. Both ABL and TPTD increased the bone formation marker serum P1NP with little effect on the bone resorption maker urine DPD/Cr, suggesting anabolic effects on bone. In human osteoblastic cells, both peptides increased the expression of bone resorption-related factors such as RANKL/OPG and M-CSF, and the effects of ABL were significantly attenuated as compared with those of TPTD under transient 6-h treatment, although no significant differences were found under continuous treatment. In contrast, ABL and TPTD similarly promoted the expression of bone formation-related factors, IGF-1 and osteocalcin. In addition, there were no significant differences in the effects on WNT signaling inhibitors such as sclerostin and dickkopf-related protein 1 (DKK1) between the two peptides. These results demonstrate that ABL exerts bone anabolic effects in OVX rats. It is also indicated that ABL stimulates the expression of RANKL/OPG and M-CSF less than TPTD, while showing similar effects on bone formation-related factors and WNT signaling inhibitors in vitro. The profile of ABL indicates that it would be a suitable bone anabolic agent for osteoporosis.

Assessment of Bone Quality in Osteoporosis Treatment with Bone Anabolic Agents: Really Something New?

Osteoporosis is a chronic pathologic condition, particularly of the elderly, in which a reduction of bone mineral density (BMD) weakens bone, leading to the so-called fragility fractures, most often of spine and femur. The gold standard exam for the quantitative measurement of BMD is the dual X-ray photon absorptiometry (DXA), a radiological method. However, a relevant number of fragility fractures occurs in the range of normal BMD values, meaning that also qualitative aspects of bone play a role, namely bone architecture and bone geometry. Bone structure is investigated by microCT and histomorphometry, which necessitate an invasive approach with a biopsy, usually taken at the iliac crest, not the typical site of fragility fractures. New tools, trabecular bone score (TBS) and hip structural analysis (HSA), obtained during DXA, can supply informations about bone structure of spine and femur, respectively, in a not invasive way. Therapy of osteoporosis is based on two types of drugs leading to an increase of BMD: antiresorptive and anabolic treatments. The antiresorptive drugs inhibit the osteoclasts, whereas teriparatide and, in part, strontium ranelate ameliorate bone structure. The present review deals with the relation between the anabolic drugs for osteoporosis and the cited new tools which investigate bone architecture and geometry, in order to clarify if they represent a real advantage in monitoring efficacy of osteoporosis' treatment. Data from the studies show that increases of TBS and HSA values after anabolic therapy are small and very close to their least significant change at the end of the usual period of treatment. Therefore, it is questionable if TBS and HSA are really helpful in monitoring bone quality and in defining reduction of individual fragility fracture risk during osteoporosis treatment with bone anabolic agents.

Analysis of the bone anabolic agent by intravital imaging technique.

Teriparatide, recombinant human PTH(1-34), is the only anabolic agent widely used for osteoporosis. This drug is thought to promote bone formation by modulating bone remodeling system, although the detailed mechanism remains unclear. Recently, we developed a novel intravital imaging technique to visualize mature osteoclasts and mature osteoblasts simultaneously. By means of this system, we revealed the effect of teriparatide on three-dimensional distribution and cell-to-cell interactions between these cells. Advances in these imaging studies may lead to further understanding of the intercellular network in bone metabolism.

Sclerostin Antibody Treatment Stimulates Bone Formation to Normalize Bone Mass in Male Down Syndrome Mice.

ABSTRACTDown syndrome (DS), characterized by trisomy of human chromosome 21, is associated with a variety of endocrine disorders as well as profound skeletal abnormalities. The low bone mass phenotype in DS is defined by low bone turnover due to decreased osteoclast and osteoblast activity, decreasing the utility of antiresorptive agents in people with DS. Sclerostin antibody (SclAb) is a therapeutic candidate currently being evaluated as a bone anabolic agent. Scl, the product of the sclerostin gene (SOST), inhibits bone formation through its inhibition of Wnt signaling. SclAb increases bone mass by suppressing the action of the endogenous inhibitor of bone formation, Scl. To examine the effects of SclAb on the DS bone phenotype, 8‐week‐old male wild‐type (WT) andTs65Dn DS mice were treated with 4 weekly iv injections of 100 mg/kg SclAb. Dual‐energy X‐ray absorptiometry (DXA), microCT, and dynamic histomorphometry analyses revealed that SclAb had a significant anabolic effect on both age‐matched WT littermate controls and Ts65Dn DS mice that was osteoblast mediated, without significant changes in osteoclast parameters. SclAb treatment significantly increased both cortical and trabecular bone mass at multiple sites; SclAb treatment resulted in the normalization of Ts65Dn bone mineral density (BMD) to WT levels in the proximal tibia, distal femur, and whole body. Ex vivo bone marrow cultures demonstrated that SclAb increased the recruitment of the mesenchymal progenitors into the osteoblast lineage, as indicated by increased alkaline phosphatase–positive colonies, with no effect on osteoclast differentiation. Together, in the setting of a murine model of DS and decreased bone turnover, SclAb had a potent anabolic effect. SclAb stimulated bone formation and increased osteoblastogenesis without affecting osteoclastogenesis or bone resorption. These data suggest that SclAb is a promising new therapy to improve bone mass and reduce fracture risk in the face of the low bone mass and turnover prevalent in the DS population. © 2017 The Authors JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Intraoperative delivery of the Notch ligand Jagged-1 regenerates appendicular and craniofacial bone defects

Each year, 33% of US citizens suffer from a musculoskeletal condition that requires medical intervention, with direct medical costs approaching $1 trillion USD per year. Despite the ubiquity of skeletal dysfunction, there are currently limited safe and efficacious bone growth factors in clinical use. Notch is a cell–cell communication pathway that regulates self-renewal and differentiation within the mesenchymal/osteoblast lineage. The principal Notch ligand in bone, Jagged-1, is a potent osteoinductive protein that positively regulates post-traumatic bone healing in animals. This report describes the temporal regulation of Notch during intramembranous bone formation using marrow ablation as a model system and demonstrates decreased bone formation following disruption of Jagged-1 in mesenchymal progenitor cells. Notch gain-of-function using recombinant Jagged-1 protein on collagen scaffolds promotes healing of craniofacial (calvarial) and appendicular (femoral) surgical defects in both mice and rats. Localized delivery of Jagged-1 promotes bone apposition and defect healing, while avoiding the diffuse bone hypertrophy characteristic of the clinically problematic bone morphogenetic proteins. It is concluded that Jagged-1 is a bone-anabolic agent with therapeutic potential for regenerating traumatic or congenital bone defects.

Metabolic Bone Diseases and Total Hip Arthroplasty: Preventing Complications.

Metabolic bone diseases are a diverse group of conditions characterized by abnormalities in calcium metabolism and/or bone cell physiology. These unbalanced processes can eventually lead to bony deformities and altered joint biomechanics, resulting in degenerative joint disease. Not infrequently, patients with metabolic bone diseases have restricting hip joint pain that ultimately necessitates hip arthroplasty. To minimize complications, the surgeon must consider the particular characteristics of these patients. The surgical and medical management of patients with metabolic bone diseases undergoing hip arthroplasty requires appropriate preoperative diagnosis, careful attention to the technical challenges of surgery, and strategies to maximize the long-term results of the surgical intervention, such as the use of bone anabolic and anticatabolic agents.

Bone Therapeutics: Safety Considerations, Session Summary.

This session was a series of presentations focused on safety considerations for late stage or currently marketed bone therapeutic agents. The first presentation was an overview of a major regulatory requirement in the nonclinical filing package for bone therapeutics, studies designed to assess the impact of an agent on bone quality. Two presentations focused on safety issues associated with drugs whose primary mechanism of action is inhibition of bone resorption. Typical findings associated with this class of agents in general and reproductive toxicology studies were reviewed, highlighting INHAND (International Harmonization of Nomenclature and Diagnostic Criteria) nomenclature. This was followed by an overview of safety issues that have been identified largely through clinical experience. Similar presentations followed emphasizing safety and regulatory issues associated with classes of drugs whose primary mechanism of action is stimulation of bone formation known broadly as bone anabolic agents. The major focus of these discussions was carcinogenicity risk assessment. The final presentation was an introduction to a rapidly evolving area in bone therapeutics, treatment of rare genetic bone diseases, and the developmental challenges associated with these indications and novel therapeutic modalities.

Medication management after intramedullary nailing of atypical fractures

Long term use of bisphosphonates (BPs) in osteoporotic patients may be associated with stress fractures of the sub-trochanteric and shaft area of the femur, so called “atypical” femoral fractures (AFF). Specific diagnosis criteria have been defined with 5 major features; the presence of four of them characterizes the AFF. Once a complete fracture occurred, the best surgical treatment is closed reduction and intra medullary nailing. The BPs treatment should be stopped immediately after an AFF occurred. Dietary calcium and vitamin D status should be assessed, and adequate supplementation prescribed. Principle of combination of a systematic bone anabolic treatment is strongly debated. The recombinant parathyroid hormone 1–34 or Teriparatide ® (TPTD) has an anabolic effect on bone and prevent osteoporotic fractures. Available preclinical and clinical data have also demonstrated the role played by TPTD to enhance bone fracture healing and the potential beneficial effect in impaired fracture healing or specific clinical condition like AFFs. Some authors have proposed in incomplete BP use stress fractures different medical management according the MRI findings. Bone anabolic agents may be promising both to prevent healing complications in AFFs and to promote healing in conservative treatment of incomplete AFFs. More clinical studies are needed to confirm this hypothesis.

Profile of romosozumab and its potential in the management of osteoporosis.

Increased understanding of bone biology has led to the discovery of several unique signaling pathways that regulate bone formation and resorption. The Wnt signaling pathway plays a significant role in skeletal development, adult skeletal homeostasis, and bone remodeling. Sclerostin is an inhibitor of the Wnt signaling pathway. Romosozumab, a humanized monoclonal antibody that binds to sclerostin, prevents sclerostin from exerting this inhibitory effect. Therefore, in the presence of romosozumab, the Wnt signaling pathway is activated leading to bone formation and bone mineral density gain. Clinical studies of romosozumab have shown that this agent is one of the most potent bone anabolic agents in development to date. Romosozumab does not act solely as an anabolic agent, but rather, it has effects on increasing bone formation as well as reducing bone resorption. In the clinical studies, patients tolerated romosozumab well with no major safety signals reported. In a Phase III study, romosozumab as compared to placebo has been shown to reduce vertebral fractures by 73% after 1 year of treatment. Sequential therapy with romosozumab for 1 year followed by denosumab in the second year reduced vertebral fractures by 75% as compared to the group that received placebo for 1 year and denosumab in the second year. Romosozumab holds significant potential, by a novel mechanism of action, to expand our ability to treat osteoporosis. More studies are needed to determine the ideal setting in which romosozumab may be used to optimize osteoporosis treatment.

3-Piperidylethoxypterocarpan: A potential bone anabolic agent that improves bone quality and restores trabecular micro-architecture in ovariectomized osteopenic rats

A series of new 6H-benzofuro[3, 2-c]chromenes (BFC, pterocarpans) with structure-activity relationships were investigated for their potential use in osteoporosis treatment. One of the BFCs 3-piperidylethoxypterocarpan 20 promotes osteoblast differentiation and mineralization at a dose as low as 1 pM via activation of ER/P38MAPK/BMP-2 pathway. When evaluated for in-vivo osteogenic activity in female Sprague-Dawley rats, BFC 20 increased bone mineral density and new bone formation, compared with control at 1.0 and 10.0 mg/kg/body weight by oral gavage for 30 days. The compound was devoid of any uterotrophic effect and led to the new bone formation in adult ovariectomized osteopenic rats. BFC 20 compound also inhibited bone resorption by reducing Ovx induced increase in urinary CTx, thus exhibiting both bone anabolic and anti-catabolic action. Finally, BFC 20 treatment to Ovx rats led to improved trabecular microarchitectural restoration and exhibited therapeutic potential as a dual acting anti-osteoporotic agent for the management of osteoporosis.

New methods for the evaluation of bone quality. Bone anabolic agents and bone quality.

Teriparatide(TPTD)products that can be used clinically in Japan include a daily subcutaneous injection form produced by genetic engineering and a weekly subcutaneous injectable TPTD acetate form produced by chemical synthesis. Published reports indicate that both forms exhibit excellent antifracture efficacy, and as the only anabolic agents that promote osteogenesis, TPTD products now occupy a prominent position. However, the two forms differ considerably, not only in frequency of administration, but also in mechanism of action. The daily form stimulates osteogenesis and accompanying resorption through more radical high bone turnover, and early in the course of treatment, intracortical porosity and apatite crystallization decrease, while immature collagen crosslinking increases. However, because daily formulations also produce an increase in cortical surface area or cortical thickness, the effects are counterbalanced, and bone strength is maintained. In contrast, the weekly form prioritizes osteogenesis, and by concurrently lowering turnover below pretreatment levels, improves trabecular bone mass and structure, and enhances strength without leading to cortical porosity and other undesirable phenomena. Abaloparatide, a PTHrP(1-34)analog that is homologous with the biologically active site of PTH drugs, is currently under development, and we eagerly anticipate further clarification of the mechanism of action of each formulation on bone.

PIXE study on the effects of parathyroid hormone on elemental content in rat bones

Parathyroid hormone (PTH) has attracted considerable interest as a bone anabolic agent. PTH plays a central role in regulating calcium phosphate metabolism and its increases in production in response to low serum calcium levels. A continuous hypersecretion of PTH, as occurs in primary hyperparathyroidism, leads to bone resorption. In this study, the effect of different doses of parathyroid hormone (PTH) on bone mineral content (BMC) in rats was investigated by particle-induced X-ray emission (PIXE). This study will help in investigating further the toxicity of extremely high doses of PTH on BMC. For this study, PTH at doses of 15, 45, or 135μg/kg/day were applied to 9-month-old male and female Sprague Dawley (SD) rats. The concentrations of calcium (Ca), phosphorus (P), strontium (Sr), and zinc (Zn) were measured for bone treatment of PTH. From the results of the research, it was revealed that the biomechanical characteristics of the bone as well as the bone mass were enhanced after the treatment. It was further found that the concentrations of other elements also increased, excluding Zn. This research proved that PTH assists in the treatment of osteoporosis as revealed by the characteristics of different elements. PIXE can be used to determine the concentrations of bone mineral content.

Enhancer of Zeste Homolog 2 Inhibition Stimulates Bone Formation and Mitigates Bone Loss Caused by Ovariectomy in Skeletally Mature Mice

Perturbations in skeletal development and bone degeneration may result in reduced bone mass and quality, leading to greater fracture risk. Bone loss is mitigated by bone protective therapies, but there is a clinical need for new bone-anabolic agents. Previous work has demonstrated that Ezh2 (enhancer of zeste homolog 2), a histone 3 lysine 27 (H3K27) methyltransferase, suppressed differentiation of osteogenic progenitors. Here, we investigated whether inhibition of Ezh2 can be leveraged for bone stimulatory applications. Pharmacologic inhibition and siRNA knockdown of Ezh2 enhanced osteogenic commitment of MC3T3 preosteoblasts. Next generation RNA sequencing of mRNAs and real time quantitative PCR profiling established that Ezh2 inactivation promotes expression of bone-related gene regulators and extracellular matrix proteins. Mechanistically, enhanced gene expression was linked to decreased H3K27 trimethylation (H3K27me3) near transcriptional start sites in genome-wide sequencing of chromatin immunoprecipitations assays. Administration of an Ezh2 inhibitor modestly increases bone density parameters of adult mice. Furthermore, Ezh2 inhibition also alleviated bone loss in an estrogen-deficient mammalian model for osteoporosis. Ezh2 inhibition enhanced expression of Wnt10b and Pth1r and increased the BMP-dependent phosphorylation of Smad1/5. Thus, these data suggest that inhibition of Ezh2 promotes paracrine signaling in osteoblasts and has bone-anabolic and osteoprotective potential in adults.

Bone Regeneration Using Gene-Activated Matrices.

Gene delivery to bone is a potential therapeutic strategy for directed, sustained, and regulated protein expression. Tissue engineering strategies for bone regeneration include delivery of proteins, genes (viral and non-viral-mediated delivery), and/or cells to the bone defect site. In addition, biomimetic scaffolds and scaffolds incorporating bone anabolic agents greatly enhance the bone repair process. Regional gene therapy has the potential of enhancing bone defect healing and bone regeneration by delivering osteogenic genes locally to the osseous lesions, thereby reducing systemic toxicity and the need for using supraphysiological dosages of therapeutic proteins. By implanting gene-activated matrices (GAMs), sustained gene expression and continuous osteogenic protein production in situ can be achieved in a way that stimulates osteogenesis and bone repair within osseous defects. Critical parameters substantially affecting the therapeutic efficacy of gene therapy include the choice of osteogenic transgene(s), selection of non-viral or viral vectors, the wound environment, and the selection of ex vivo and in vivo gene delivery strategies, such as GAMs. It is critical for gene therapy applications that clinically beneficial amounts of proteins are synthesized endogenously within and around the lesion in a sustained manner. It is therefore necessary that reliable and reproducible methods of gene delivery be developed and tested for their efficacy and safety before translating into clinical practice. Practical considerations such as the age, gender, and systemic health of patients and the nature of the disease process also need to be taken into account in order to personalize the treatments and progress towards developing a clinically applicable gene therapy for healing bone defects. This review discusses tissue engineering strategies to regenerate bone with specific focus on non-viral gene delivery systems.

Targeting NO Signaling for the Treatment of Osteoporosis

Osteoporosis is a major health problem, affecting over 10 million people in the U.S. and leading to fractures associated with significant morbidity and mortality. Normal bone mass is maintained by a balance between the anabolic effects of osteoblasts and catabolic effects of osteoclasts. Most osteoporosis therapies inhibit osteoclast activity; parathyroid hormone is the only FDA-approved agent that increases osteoblast activity, but its efficacy wanes over time, and there is a need for novel bone-anabolic agents. Nitrates, which generate nitric oxide (NO) in vivo, prevent bone loss from estrogen-deficiency in rodents, and some clinical data suggest beneficial effects of nitrates in post-menopausal osteoporosis. Here, we examine the sources of NO and regulation of NO synthesis in bone cells, review the effects of NO in cells of osteoblastic and osteoclastic lineage, and summarize existing preclinical and clinical data to document the skeletal effects of NO in vivo. Based on the anabolic and anti-resorptive effects of NO in bone, novel NO donors and other strategies to enhance NO production and bioavailability in vivo may represent a new treatment strategy for osteoporosis. Keywords: Osteoporosis, osteoclastic lineage, novel bone-anabolic agents.

A Novel, Direct NO Donor Regulates Osteoblast and Osteoclast Functions and Increases Bone Mass in Ovariectomized Mice.

Most US Food and Drug Administration (FDA)-approved treatments for osteoporosis target osteoclastic bone resorption. Only PTH derivatives improve bone formation, but they have drawbacks, and novel bone-anabolic agents are needed. Nitrates, which generate NO, improved BMD in estrogen-deficient rats and may improve bone formation markers and BMD in postmenopausal women. However, nitrates are limited by induction of oxidative stress and development of tolerance, and may increase cardiovascular mortality after long-term use. Here we studied nitrosyl-cobinamide (NO-Cbi), a novel, direct NO-releasing agent, in a mouse model of estrogen deficiency-induced osteoporosis. In murine primary osteoblasts, NO-Cbi increased intracellular cGMP, Wnt/β-catenin signaling, proliferation, and osteoblastic gene expression, and protected cells from apoptosis. Correspondingly, in intact and ovariectomized (OVX) female C57Bl/6 mice, NO-Cbi increased serum cGMP concentrations, bone formation, and osteoblastic gene expression, and in OVX mice, it prevented osteocyte apoptosis. NO-Cbi reduced osteoclasts in intact mice and prevented the known increase in osteoclasts in OVX mice, partially through a reduction in the RANKL/osteoprotegerin gene expression ratio, which regulates osteoclast differentiation, and partially through direct inhibition of osteoclast differentiation, observed in vitro in the presence of excess RANKL. The positive NO effects in osteoblasts were mediated by cGMP/protein kinase G (PKG), but some of the osteoclast-inhibitory effects appeared to be cGMP-independent. NO-Cbi increased trabecular bone mass in both intact and OVX mice, consistent with its in vitro effects on osteoblasts and osteoclasts. NO-Cbi is a novel direct NO-releasing agent that, in contrast to nitrates, does not generate oxygen radicals, and combines anabolic and antiresorptive effects in bone, making it an excellent candidate for treating osteoporosis. © 2016 American Society for Bone and Mineral Research.

Discovery of novel dihydrobenzofuran cyclopropane carboxylic acid based calcium sensing receptor antagonists for the treatment of osteoporosis

In a search for novel small molecule calcium-sensing receptor (CaSR) antagonists as oral bone anabolic agents, we discovered dihydrobenzofuran cyclopropane carboxylic acid derivatives, such as 12f (IC50=27.6nM), are highly potent calcium-sensing receptor antagonists. Studies in rats established that compound 12f stimulates parathyroid hormone (PTH) release in a fast-acting, pulsatile manner.

Short Anabolic Peptides for Bone Growth.

Loss of bone occurs in the age-related skeletal disorder, osteoporosis, leading to bone fragility and increased incidence of fractures, which are associated with enormous costs and substantial morbidity and mortality. Recent data indicate that osteoporotic fractures are more common than other diseases, which usually attract public attention (e.g., heart attack and breast cancer). The prevention and treatment of this skeletal disorder are therefore of paramount importance. Majority of osteoporosis medications restore skeletal balance by reducing osteoclastic activity, thereby reducing bone resorption. These agents, however, do not regenerate damaged bone tissue, leaving limited options for patients once bone loss has occurred. Recently, attention has turned to bone-anabolic agents. Such agents have the ability to increase bone mass and strength, potentially reversing structural damage. To date, only one bone-anabolic drug is available in the market. The discovery of more novel, cost-effective bone anabolic agents is therefore a priority to treat those suffering from this disabling condition. Short peptides offer an important alternative for the development of novel bone-anabolic agents given their high target binding specificity, which translates into potent activity with limited side effects. This review summarizes attempts in the identification of bone-anabolic peptides, and their development for promoting bone growth.

Small molecule inhibitors of the Dishevelled-CXXC5 interaction are new drug candidates for bone anabolic osteoporosis therapy.

Bone anabolic agents promoting bone formation and rebuilding damaged bones would ideally overcome the limitations of anti‐resorptive therapy, the current standard prescription for osteoporosis. However, the currently prescribed parathyroid hormone (PTH)‐based anabolic drugs present limitations and adverse effects including osteosarcoma during long‐term use. Also, the antibody‐based anabolic drugs that are currently being developed present the potential limits in clinical application typical of macromolecule drugs. We previously identified that CXXC5 is a negative feedback regulator of the Wnt/β‐catenin pathway via its interaction with Dishevelled (Dvl) and suggested the Dvl–CXXC5 interaction as a potential target for anabolic therapy of osteoporosis. Here, we screened small‐molecule inhibitors of the Dvl–CXXC5 interaction via a newly established in vitro assay system. The screened compounds were found to activate the Wnt/β‐catenin pathway and enhance osteoblast differentiation in primary osteoblasts. The bone anabolic effects of the compounds were shown using ex vivo‐cultured calvaria. Nuclear magnetic resonance (NMR) titration analysis confirmed interaction between Dvl PDZ domain and KY‐02061, a representative of the screened compounds. Oral administration of KY‐02327, one of 55 newly synthesized KY‐02061 analogs, successfully rescued bone loss in the ovariectomized (OVX) mouse model. In conclusion, small‐molecule inhibitors of the Dvl–CXXC5 interaction that block negative feedback regulation of Wnt/β‐catenin signaling are potential candidates for the development of bone anabolic anti‐osteoporosis drugs.

Changes in bone quality and strength with bone-forming agents

Among the anti-osteoporotic agents clinically available in Japan, teriparatide is the only bone anabolic agent offering potent osteogenic effects. Regarding bone quality, studies have shown that teriparatide increases bone collagen content and enzymatic cross-links and decreases pentosidine, a surrogate marker of advanced glycation end-products. In addition to these improvements in bone collagen cross-links, increased bone mineral density and improvement of bone microarchitecture contribute to increases in bone strength with teriparatide administration. Teriparatide has been shown to markedly reduce the risk of new vertebral fractures in patients with osteoporosis. Recent clinical studies have suggested a role for teriparatide in accelerating healing for osteoporotic fractures. Teriparatide is promising for the prevention of vertebral collapse progression after vertebral fracture.