RANKL inhibition improves muscle strength and insulin sensitivity and restores bone mass

Clostridium butyricum Alleviates Gut Microbiota Alteration-Induced Bone Loss after Bariatric Surgery by Promoting Bone Autophagy

Bariatric surgery is the most common and effective treatment of severe obesity; however, these bariatric procedures always result in detrimental effects on bone metabolism by underlying mechanisms. This study aims to investigate the skeletal response to bariatric surgery and to explore whether Clostridium butyricum alleviates gut microbiota alteration-induced bone loss after bariatric surgery. Consequently, male SD rats received Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) surgery, respectively, followed by body weight recording. The bone loss after bariatric surgery was further determined by dual-energy X-ray absorptiometry (DXA), micro-CT measurement, histologic analyses, and Western blot. Besides, 16S rDNA gene sequencing was performed to determine the gut microbiota alteration after surgery, and intervention with fecal microbiota from RYGB donor was conducted in obese SD rats, followed by C. butyricum administration. Accordingly, rats in the RYGB and SG groups maintained sustained weight loss, and DXA and micro-CT measurement further demonstrated significant bone loss after bariatric surgery. Besides, histologic and Western blot analyses validated enhanced osteoclastogenesis and inhibited osteoblastogenesis and defective autophagy after surgery. The 16S rDNA gene sequencing suggested a significant alteration of gut microbiota composition in the RYGB group, and intervention with fecal microbiota from RYGB donor further determined that this kind of alteration contributed to the bone loss after RYGB. Meanwhile, C. butyricum might protect against this postoperative bone loss by promoting osteoblast autophagy. In summary, this study suggests novel mechanisms to clarify the skeletal response to bariatric surgery and provides a potential candidate for the treatment of bone disorder among bariatric patients. SIGNIFICANCE STATEMENT: The significance of this study is the discovery of obvious bone loss and defective autophagy after bariatric surgery. Besides, it is revealed that gut microbiota alterations could be the reason for impaired bone mass after bariatric surgery. Furthermore, Clostridium butyricum could alleviate the gut microbiota alteration-induced bone loss after bariatric surgery by promoting osteoblast autophagy.

Role of myokines and osteokines in cancer cachexia

Cancer-induced muscle wasting, i.e. cachexia, is associated with different types of cancer such as pancreatic, colorectal, lung, liver, gastric and esophageal. Cachexia affects prognosis and survival in cancer, and it is estimated that it will be the ultimate cause of death for up to 30% of cancer patients. Musculoskeletal alterations are known hallmarks of cancer cachexia, with skeletal muscle atrophy and weakness as the most studied. Recent evidence has shed light on the presence of bone loss in cachectic patients, even in the absence of bone-metastatic disease. In particular, we and others have shown that muscle and bone communicate by exchanging paracrine and endocrine factors, known as myokines and osteokines. This review will focus on describing the role of the most studied myokines, such as myostatin, irisin, the muscle metabolite β-aminoisobutyric acid, BAIBA, and IL-6, and osteokines, including TGF-β, osteocalcin, sclerostin, RANKL, PTHrP, FGF23, and the lipid mediator, PGE₂ during cancer-induced cachexia. The interplay of muscle and bone factors, together with tumor-derived soluble factors, characterizes a complex clinical scenario in which musculoskeletal alterations are amongst the most debilitating features. Understanding and targeting the "secretome" of cachectic patients will likely represent a promising strategy to preserve bone and muscle during cancer cachexia thereby enhancing recovery.

Improved Bone Quality and Bone Healing of Dystrophic Mice by Parabiosis

Duchenne muscular dystrophy (DMD) is a degenerative muscle disorder characterized by a lack of dystrophin expression in the sarcolemma of muscle fibers. DMD patients acquire bone abnormalities including osteopenia, fragility fractures, and scoliosis indicating a deficiency in skeletal homeostasis. The dKO (dystrophin/Utrophin double knockout) is a more severe mouse model of DMD than the mdx mouse (dystrophin deficient), and display numerous clinically-relevant manifestations, including a spectrum of degenerative changes outside skeletal muscle including bone, articular cartilage, and intervertebral discs. To examine the influence of systemic factors on the bone abnormalities and healing in DMD, parabiotic pairing between dKO mice and mdx mice was established. Notably, heterochronic parabiosis with young mdx mice significantly increased bone mass and improved bone micro-structure in old dKO-hetero mice, which showed progressive bone deterioration. Furthermore, heterochronic parabiosis with WT C56/10J mice significantly improved tibia bone defect healing in dKO-homo mice. These results suggest that systemic blood-borne factor(s) and/or progenitors from WT and young mdx mice can influence the bone deficiencies in dKO mice. Understanding these circulating factors or progenitor cells that are responsible to alleviate the bone abnormalities in dKO mice after heterochronic parabiosis might be useful for the management of poor bone health in DMD.

Muscle-Bone Crosstalk in Chronic Kidney Disease: The Potential Modulatory Effects of Exercise

Chronic kidney disease (CKD) is a prevalent worldwide public burden that increasingly compromises overall health as the disease progresses. Two of the most negatively affected tissues are bone and skeletal muscle, with CKD negatively impacting their structure, function and activity, impairing the quality of life of these patients and contributing to morbidity and mortality. Whereas skeletal health in this population has conventionally been associated with bone and mineral disorders, sarcopenia has been observed to impact skeletal muscle health in CKD. Indeed, bone and muscle tissues are linked anatomically and physiologically, and together regulate functional and metabolic mechanisms. With the initial crosstalk between the skeleton and muscle proposed to explain bone formation through muscle contraction, it is now understood that this communication occurs through the interaction of myokines and osteokines, with the skeletal muscle secretome playing a pivotal role in the regulation of bone activity. Regular exercise has been reported to be beneficial to overall health. Also, the positive regulatory effect that exercise has been proposed to have on bone and muscle anatomical, functional, and metabolic activity has led to the proposal of regular physical exercise as a therapeutic strategy for muscle and bone-related disorders. The detection of bone- and muscle-derived cytokine secretion following physical exercise has strengthened the idea of a cross communication between these organs. Hence, this review presents an overview of the impact of CKD in bone and skeletal muscle, and narrates how these tissues intrinsically communicate with each other, with focus on the potential effect of exercise in the modulation of this intercommunication.

An Overview of the Molecular Mechanisms Contributing to Musculoskeletal Disorders in Chronic Liver Disease: Osteoporosis, Sarcopenia, and Osteoporotic Sarcopenia

The prevalence of osteoporosis and sarcopenia is significantly higher in patients with liver disease than in those without liver disease and osteoporosis and sarcopenia negatively influence morbidity and mortality in liver disease, yet these musculoskeletal disorders are frequently overlooked in clinical practice for patients with chronic liver disease. The objective of this review is to provide a comprehensive understanding of the molecular mechanisms of musculoskeletal disorders accompanying the pathogenesis of liver disease. The increased bone resorption through the receptor activator of nuclear factor kappa (RANK)-RANK ligand (RANKL)-osteoprotegerin (OPG) system and upregulation of inflammatory cytokines and decreased bone formation through increased bilirubin and sclerostin and lower insulin-like growth factor-1 are important mechanisms for osteoporosis in patients with liver disease. Sarcopenia is associated with insulin resistance and obesity in non-alcoholic fatty liver disease, whereas hyperammonemia, low amount of branched chain amino acids, and hypogonadism contributes to sarcopenia in liver cirrhosis. The bidirectional crosstalk between muscle and bone through myostatin, irisin, β-aminoisobutyric acid (BAIBA), osteocalcin, as well as the activation of the RANK and the Wnt/β-catenin pathways are associated with osteosarcopenia. The increased understandings for these musculoskeletal disorders would be contributes to the development of effective therapies targeting the pathophysiological mechanism involved.

The Impact of Antiosteoporotic Drugs on Glucose Metabolism and Fracture Risk in Diabetes: Good or Bad News?

Osteoporosis and diabetes mellitus represent global health problems due to their high, and increasing with aging, prevalence in the general population. Osteoporosis can be successfully treated with both antiresorptive and anabolic drugs. While these drugs are clearly effective in reducing the risk of fracture in patients with postmenopausal and male osteoporosis, it is still unclear whether they may have the same efficacy in patients with diabetic osteopathy. Furthermore, as bone-derived cytokines (osteokines) are able to influence glucose metabolism, it is conceivable that antiosteoporotic drugs may have an effect on glycemic control through their modulation of bone turnover that affects the osteokines’ release. These aspects are addressed in this narrative review by means of an unrestricted computerized literature search in the PubMed database. Our findings indicate a balance between good and bad news. Active bone therapies and their modulation of bone turnover do not appear to play a clinically significant role in glucose metabolism in humans. Moreover, there are insufficient data to clarify whether there are any differences in the efficacy of antiosteoporotic drugs on fracture incidence between diabetic and nondiabetic patients with osteoporosis. Although more studies are required for stronger recommendations to be issued, bisphosphonates appear to be the first-line drug for treatment of osteoporosis in diabetic patients, while denosumab seems preferable for older patients, particularly for those with impaired renal function, and osteoanabolic agents should be reserved for patients with more severe forms of osteoporosis.

Long-term changes in lean mass in postmenopausal women and the effects of osteoporosis pharmacotherapy: A 10-year longitudinal study

OBJECTIVES

Although sarcopenia is diagnosed using appendicular lean mass (ALM), only a few long-term studies on changes in both ALM and bone mineral density (BMD) have been reported. The purposes of this study are to evaluate the changes in the parameters of lean mass and bone mass over a 10-year interval and to estimate the effects of osteoporosis pharmacotherapy on muscle.

METHODS

A total of 175 postmenopausal women were evaluated at baseline and after 10 years for BMD, ALM, fat mass, height, and weight. Subjects were further divided into an osteoporosis treatment group (n = 60) and a control group (n = 67) according to whether they had received pharmacotherapy for > 5 years. This was followed by propensity score matching for age, height, weight, and body mass index (BMI), and estimated parameters were compared between groups.

RESULTS

Height, weight, ALM, and fat mass decreased significantly over 10 years (P < 0.05). However, lean mass index (LMI), derived as the ALM divided by the height squared, increased significantly (P < 0.001). BMD increased significantly with osteoporosis treatment (P < 0.05), while no significant differences were observed between the osteoporosis treatment and control groups in the changes to ALM or fat mass.

CONCLUSIONS

ALM was decreased, while LMI was significantly increased. This contradictory result seems to be affected by age-related height loss. Thus, the effect of height loss needs to be considered when sarcopenia is evaluated longitudinally using LMI.

Postmenopausal osteoporosis coexisting with other metabolic diseases: Treatment considerations

In postmenopausal women, osteoporosis may coexist with other metabolic diseases, including, but not limited to, obesity, diabetes, nonalcoholic fatty liver disease (NAFLD), dyslipidemia and cardiovascular disease (CVD). This association may lie beyond simple coincidence owing to high prevalence of all these diseases, especially in the aging population, as common pathogenetic mechanisms between them and osteoporosis may exist. In this context, anti-osteoporotic medications may affect the pathogenesis of some of these metabolic diseases; this is an important consideration when selecting the most appropriate medication for osteoporotic patients with coexistent metabolic diseases. Conversely, some current or emerging medications for metabolic diseases adversely affect bone metabolism and, if possible, should be avoided in women with postmenopausal osteoporosis. The main aim of this review is to summarize the evidence on anti-osteoporotic treatment in postmenopausal women with concomitant metabolic diseases, i.e. obesity, diabetes, NAFLD, dyslipidemia and CVD. The secondary aim is to present data on the effect of current or emerging medication for metabolic diseases on bone metabolism of postmenopausal women. Deeper understanding of the underlying links between osteoporosis and metabolic diseases may have clinical implications. However, mechanistic studies are needed to elucidate the potential pathophysiological links, as well as clinical trials in women with postmenopausal osteoporosis coexisting with specific metabolic diseases; these may guide clinical practice in the future for the selection of the best anti-osteoporotic medication for each patient with specific metabolic diseases.

Isobavachalcone prevents osteoporosis by suppressing activation of ERK and NF-κB pathways and M1 polarization of macrophages

Estrogen receptors alpha (ERα), a member of the nuclear receptor protein family, was found to play an important role in maintaining bone mass. Its downstream signaling proteins such as ERK and NF-κB were reported to be involved in development of osteoporosis, which meant that targeting ERα might be an effective strategy for searching for new drugs to prevent bone loss. In this study, we demonstrate that isobavachalcone (ISO), as one of bioactive compounds isolated from Psoralea corylifoliaLinn, has high affinity with ERα. The effects of ISO are investigated on receptor activator of NF-κB ligand (RANKL)-induced osteocalstogenesis. It is reported that ISO inhibits the RANKL-mediated increase of osteoclast-related genes MMP9, cathepsink and TRAR in RAW264.7 cells. Moreover, in vitro experiment shows that ISO exhibits an inhibitory effect on ERK and NF-κB signaling pathway, and suppresses RANKL-induced expression of osteoclast-related transcription factors NFATc1 and c-Fos. However, the impact of ISO in these molecules is eliminated by the application of ERα antagonist AZD9496.We further verified pharmacological effects of ISO in ovariectomized osteoporotic mice, and ISO significantly prevented bone loss and decreased M1 polarization of macrophages from marrow and spleen. Collectively, our data suggest that ISO prevents osteoporosis via suppressing activation of ERK and NF-κB signaling pathways as well as M1 polarization of macrophages.

A Vicious Cycle of Osteosarcopeniain Inflammatory Bowel Diseases-Aetiology, Clinical Implications and Therapeutic Perspectives

Sarcopenia is a disorder characterized by a loss of muscle mass which leads to the reduction of muscle strength and a decrease in the quality and quantity of muscle. It was previously thought that sarcopenia was specific to ageing. However, sarcopenia may affect patients suffering from chronic diseases throughout their entire lives. A decreased mass of muscle and bone is common among patients with inflammatory bowel disease (IBD). Since sarcopenia and osteoporosis are closely linked, they should be diagnosed as mutual consequences of IBD. Additionally, multidirectional treatment of sarcopenia and osteoporosis including nutrition, physical activity, and pharmacotherapy should include both disorders, referred to as osteosarcopenia.

The Role of Bone in Muscle Wasting

This review describes the role of bone resorption in muscle atrophy as well as in muscle protein anabolism. Both catabolic and anabolic pathways involve components of the proinflammatory cytokine families and release of factors stored in bone during resorption. The juxtaposition of the catabolic and anabolic resorption-dependent pathways raises new questions about control of release of factors from bone, quantity of release in a variety of conditions, and relation of factors released from bone. The catabolic responses involve release of calcium from bone into the circulation resulting in increased inflammatory response in intensity and/or duration. The release of transforming growth factor beta (TGF-β) from bone suppresses phosphorylation of the AKT/mTOR pathway and stimulates ubiquitin-mediated breakdown of muscle protein. In contrast, muscle IL-6 production is stimulated by undercarboxylated osteocalcin, which signals osteoblasts to produce more RANK ligand, stimulating resorptive release of undercarboxylated osteocalcin, which in turn stimulates muscle fiber nutrient uptake and an increase in muscle mass.

Adipose-specific knockout of ubiquitin-conjugating enzyme E2L6 (Ube2l6) reduces diet-induced obesity, insulin resistance, and hepatic steatosis

Ubiquitin/ISG15-conjugating enzyme E2 L6 (UBE2L6/Ube2l6) catalyzes protein ISGylation and ubiquitylation, post-translational modifications which regulate protein stability. Ube2l6 plays a role in promoting in vitro adipogenesis; however, its mechanism(s) of action and in vivo effects remain unknown. Here, we discovered that UBE2L6 levels were upregulated, and UBE2L6 and adipose triglyceride lipase (ATGL/Atgl) levels were negatively correlated, in white adipose tissue (WAT) from obese humans and obese mice. Therefore, we employed adipose-specific Ube2l6 knockout (Ube2l6^AKO) mice and age-matched Ube2l6^flox/flox controls to assess adipocyte Ube2l6's role in high-fat diet (HFD)-induced obesity, insulin resistance, and hepatic steatosis. HFD-fed Ube2l6^AKO mice displayed lower subcutaneous and visceral WAT mass levels relative to controls. HFD-fed Ube2l6^AKO mice also showed WAT adipocyte hypoplasia and hypotrophy as well as enhanced whole-body metabolic activity relative to controls. Furthermore, glucose intolerance, insulin resistance, compensatory hyperinsulinemia, hypercholesterolemia, and hepatic steatosis were lower in HFD-fed Ube2l6^AKO mice as compared to controls. Mechanistically, we found that Atgl protein expression and Atgl-mediated lipolysis were negatively regulated by Ube2l6's promotion of Atgl protein ubiquitylation. Collectively, adipocyte Ube2l6 functions as a negative regulator of Atgl protein stability and, consequently, promotes HFD-induced obesity, insulin resistance, and hepatic steatosis.

Distrectual osteosarcopenia in limb disuse: case report and mini literature review

Osteosarcopenia is a new concept and it is the association of osteoporosis and sarcopenia. Both of these pathologies are more frequent in elderly people and generally affects all the skeleton increasing risk of falls and fractures, loss of global function, fragility, and mortality, and also surgical failures. The coexistence of these conditions derives from a close relationship, not only anatomical, between bone and muscle tissues. Sometimes they can involve only a skeleton segment, due to a local disuse, causing a different form of sarcopenia. In this clinical case, Authors describes a case of isolated lower limb osteosarcopenia in a young non-osteoporotic patient, due to a prolonged limb disuse, complicated by surgical treatment failure for previous pathology, diagnosed by clinical, laboratory, instrumental and histopathological exams.

Bone and Muscle Crosstalk in Aging

Osteoporosis and sarcopenia are two age-related diseases that affect the quality of life in the elderly. Initially, they were thought to be two independent diseases; however, recently, increasing basic and clinical data suggest that skeletal muscle and bone are both spatially and metabolically connected. The term "osteosarcopenia" is used to define a condition of synergy of low bone mineral density with muscle atrophy and hypofunction. Bone and muscle cells secrete several factors, such as cytokines, myokines, and osteokines, into the circulation to influence the biological and pathological activities in local and distant organs and cells. Recent studies reveal that extracellular vesicles containing microRNAs derived from senescent skeletal muscle and bone cells can also be transported and aid in regulating bone-muscle crosstalk. In this review, we summarize the age-related changes in the secretome and extracellular vesicle-microRNAs secreted by the muscle and bone, and discuss their interactions between muscle and bone cells during aging.

Mechanical loading recovers bone but not muscle lost during unloading

Space travel and prolonged bed rest are examples of mechanical unloading that induce significant muscle and bone loss. The compromised structure and function of bone and muscle owing to unloading make the reloading period a high risk for injury. To explore interactions between skeletal bone and muscle during reloading, we hypothesized that acute external mechanical loading of bone in combination with re-ambulation facilitates the proportional recovery of bone and muscle lost during hind limb suspension (HLS) unloading. Adult male C57Bl/6J mice were randomly assigned to a HLS or time-matched ground control (GC) group. After 2-weeks of HLS, separate groups of mice were studied at day 14 (no re-ambulation), day 28 (14 days re-ambulation) and day 56 (42 days re-ambulation); throughout the re-ambulation period, one limb received compressive mechanical loading and the contralateral limb served as an internal control. HLS induced loss of trabecular bone volume (BV/TV; -51 ± 2%) and muscle weight (-15 ± 2%) compared to GC at day 14. At day 28, the left tibia (re-ambulation only) of HLS mice had recovered approximately 20% of BV/TV lost during HLS, while the right tibia (re-ambulation and acute external mechanical loading) recovered to GC values of BV/TV (~100% recovery). At day 56, the right tibia continued to recover bone for some outcomes (trabecular BV/TV, trabecular thickness), while the left limb did not. Cortical bone displayed a delayed response to HLS, with a 10% greater decrease in BV/TV at day 28 compared to day 14. In contrast to bone, acute external mechanical loading during the re-ambulation period did not significantly increase muscle mass or protein synthesis in the gastrocnemius, compared to re-ambulation alone. Our results suggest acute external mechanical loading facilitates the recovery of bone during reloading following HLS unloading, but this does not translate to a concomitant recovery of muscle mass.

Exercise and Diet: Uncovering Prospective Mediators of Skeletal Fragility in Bone and Marrow Adipose Tissue

PURPOSE OF REVIEW

To highlight recent basic, translational, and clinical works demonstrating exercise and diet regulation of marrow adipose tissue (MAT) and bone and how this informs current understanding of the relationship between marrow adiposity and musculoskeletal health.

RECENT FINDINGS

Marrow adipocytes accumulate in the bone in the setting of not only hypercaloric intake (calorie excess; e.g., diet-induced obesity) but also with hypocaloric intake (calorie restriction; e.g., anorexia), despite the fact that these states affect bone differently. With hypercaloric intake, bone quantity is largely unaffected, whereas with hypocaloric intake, bone quantity and quality are greatly diminished. Voluntary running exercise in rodents was found to lower MAT and promote bone in eucaloric and hypercaloric states, while degrading bone in hypocaloric states, suggesting differential modulation of MAT and bone, dependent upon whole-body energy status. Energy status alters bone metabolism and bioenergetics via substrate availability or excess, which plays a key role in the response of bone and MAT to mechanical stimuli. Marrow adipose tissue (MAT) is a fat depot with a potential role in-as well as responsivity to-whole-body energy metabolism. Understanding the localized function of this depot in bone cell bioenergetics and substrate storage, principally in the exercised state, will aid to uncover putative therapeutic targets for skeletal fragility.

The endocrine role of bone: Novel functions of bone-derived cytokines

Bone-derived cytokines refer to various proteins and peptides that are released from the skeleton and can distribute in organisms to regulate homeostasis by targeting many organs, such as the pancreas, brain, testicles, and kidneys. In addition to providing support and movement, many studies have disclosed the novel endocrine function of bone, and bone can modulate glucose and energy metabolism as well as phosphate metabolism by versatile bone-derived cytokines. However, this specific exoskeletonfunction of bone-derived cytokines in the regulation of homeostasis and the pathological response caused by skeletal dysfunction are still not very clear, and elucidation of the above mechanisms is of great significance for understanding the pathological processes of metabolic disorders and in the search for novel therapeutic measures for maintaining organ stability and physical fitness.

Association between handgrip strength and the risk of new-onset metabolic syndrome: a population-based cohort study

OBJECTIVES

A lower relative handgrip strength (HGS) may disrupt metabolic homeostasis and then lead to metabolic syndrome (MetS). There is a paucity of longitudinal studies to examine whether relative HGS at baseline is linked to incident MetS. Thus, the purpose of the present study was to explore the association between relative HGS and new-onset MetS.

DESIGN

This is an observational and longitudinal research.A nationally representative sample of population in China.

PARTICIPANTS

A total of 3350 subjects without MetS were selected for analysis in the present study. Data are from the China Health and Retirement Longitudinal Study (2011-2015).

OUTCOME MEASURES

We calculated the relative HGS by dividing the HGS by body weight. Participants were divided into gender-specific quartiles. We estimated HRs for MetS and its components using Cox proportional hazard models according to the relative HGS categories.

RESULTS

After multiple adjustment, the risk of MetS increased with the lower quartile of relative HGS in both sexes. Using the highest quartile (Q4) as a reference, the HR for quartile Q3-1 was 1.49 (0.95, 2.34), 1.67 (1.08, 2.59) and 1.76 (1.12, 2.78), respectively, in men, and 1.14 (0.82, 1.58), 1.30 (1.02, 1.57) and 1.28 (1.03, 1.55), respectively, in women. Additionally, we observed that relative HGS was negatively or inversely associated with the risk of abdominal obesity in both sexes.

CONCLUSIONS

The current study demonstrated that relative HGS was inversely and independently associated with an increased risk of MetS and abdominal obesity, suggesting a possible role of relative HGS as a useful and simple index for muscle strength in the prediction of occurrence of MetS.

Osteoporotic Conditions Influence the Activity of Adipose-Derived Stem Cells

BACKGROUND

Estrogen deficiency decreases bone density and increases the risk of osteoporosis and fracture, thereby necessitating reconstruction of bone regeneration. As bone marrow mesenchymal stem cell (BMSCs) lose viability and differentiation potential under osteoporotic conditions, it is impossible to use autologous BMSCs for osteoporosis treatment. As an alternative, adipose-derived stem cells (ADSCs) may serve as the source of therapeutic cells.

METHOD

We evaluated the effects of osteoporosis on the functional characteristics of ADSCs. Osteoporosis was induced in ovariectomy (OVX) rat model, and the ADSCs from Sham and OVX groups were cultured and analyzed comparatively.

RESULTS

As a result, the viability was higher for the ADSCs from Sham group than those from OVX group. The analysis of the paracrine potential of ADSCs revealed the elevated levels of inflammatory and cellular senescence factors in the ADSCs from OVX group. The ADSCs from OVX group had much higher differentiation potential into adipocytes than those from the Sham group. Osteoporotic environment had no effect on the osteogenic potential of ADSCs.

CONCLUSION

Osteoporosis may reduce the activity and influence immune response of ADSCs by modulating paracrine action and adipogenic potential. These characteristics of ADSCs should be given consideration for therapeutic purpose.

New insight into unexpected bone formation by denosumab

Denosumab (Dmab) was the first monoclonal antibody (mAb) approved for the treatment of osteoporosis. It blocks the receptor activator for nuclear factor κB ligand (RANKL) and acts as a potent antiresorptive agent. In contrast to classic antiresorptive agents, Dmab treatment leads to a progressive increase in bone mass, but the mechanisms remain controversial. Recently, RANKL signaling in osteoblastogenesis and bone formation and RANKL reverse signaling in coupling bone resorption and formation were demonstrated. Thus, here we discuss the roles of RANKL signaling and RANKL reverse signaling in the bone-forming effects of Dmab.

Bone-Muscle Mutual Interactions

PURPOSE OF REVIEW

The purpose of this review is to describe the current state of our thinking regarding bone-muscle interactions beyond the mechanical perspective.

RECENT FINDINGS

Recent and prior evidence has begun to dissect many of the molecular mechanisms that bone and muscle use to communicate with each other and to modify each other's function. Several signaling factors produced by muscle and bone have emerged as potential mediators of these biochemical/molecular interactions. These include muscle factors such as myostatin, Irisin, BAIBA, IL-6, and the IGF family and the bone factors FGF-23, Wnt1 and Wnt3a, PGE2, FGF9, RANKL, osteocalcin, and sclerostin. The identification of these signaling molecules and their underlying mechanisms offers the very real and exciting possibility that new pharmaceutical approaches can be developed that will permit the simultaneous treatments of diseases that often occur in combination, such as osteoporosis and sarcopenia.

Myokines and Osteokines in the Pathogenesis of Muscle and Bone Diseases

PURPOSE OF REVIEW

In this review we aim to summarize the latest findings on the network of molecules produced by muscle and bone under physiological and pathological conditions.

RECENT FINDINGS

The concomitant onset of osteoporosis and sarcopenia is currently one of the main threats that can increase the risk of falling fractures during aging, generating high health care costs due to hospitalization for bone fracture surgery. With the growing emergence of developing innovative therapies to treat these two age-related conditions that often have common onset, a broader understanding of molecular messengers regulating the communication between muscle and bone tissue became imperative. Recently it has been highlighted that two muscle-derived signals, such as the myokines Irisin and L-BAIBA, positively affect bone tissue. In parallel, there are signals derived from bone that affect either positively the skeletal muscle, such as osteocalcin, or negatively, such as RANKL.

Relationship between Osteosarcopenia and Frailty in Patients with Chronic Liver Disease

Osteosarcopenia and frailty have a negative health impact on an aging society. This cross-sectional study aimed to investigate the clinical characteristics and relationship of osteosarcopenia and frailty in 291 patients with chronic liver disease (CLD), who comprised 137 males and 154 females, with a median age of 70.0 years. Sarcopenia was diagnosed according to the Japan Society of Hepatology criteria. Bone mineral density was measured using dual-energy X-ray absorptiometry. Frailty was defined by five parameters (exhaustion, slowness, weakness, low physical activity, and weight loss). Among the 291 patients, 49 (16.8%) and 81 (27.8%) had osteosarcopenia and frailty, respectively. Frailty and vertebral fracture were more frequently noted in patients with osteosarcopenia than in those without osteosarcopenia (79.6% vs. 17.4% and 59.2% vs. 20.2%, respectively; p < 0.001 for both). Meanwhile, osteosarcopenia and vertebral fracture were more frequently observed in patients with frailty than in those without frailty (48.1% vs. 4.8% and 49.4% vs. 18.1%, respectively; p < 0.001 for both). On multivariate analysis, frailty was an independent factor associated with osteosarcopenia (odds ratio (OR), 9.837; p < 0.001), and vice versa (OR, 10.069; p < 0.001). Osteosarcopenia and frailty were prevalent, closely interrelated, and increased the risk of vertebral fracture in patients with CLD.

Advance in Drug Delivery for Ageing Skeletal Muscle

The age-related loss of skeletal muscle, sarcopenia, is characterized by progressive loss of muscle mass, reduction in muscle strength, and dysfunction of physical performance. It has become a global health problem leading to several adverse outcomes in the ageing population. Research on skeletal muscle loss prevention and treatment is developing quickly. However, the current clinical approaches to sarcopenia are limited. Recently, novel drug delivery systems offer new possibilities for treating aged muscle loss. Herein, we briefly recapitulate the potential therapeutic targets of aged skeletal muscle and provide a concise advance in the drug delivery systems, mainly focus on the use of nano-carriers. Furthermore, we elaborately discuss the prospect of aged skeletal muscle treatment by nanotechnology approaches.

Antiresorptive activity of osteoprotegerin requires an intact heparan sulfate-binding site

Osteoprotegerin (OPG), a secreted decoy receptor for receptor activator of nuclear factor B ligand (RANKL), plays an essential role in regulating bone resorption. While much is known about the function of the N-terminal domains of OPG, which is responsible for binding to RANKL, the exact biological functions of the three C-terminal domains of OPG remain uncertain. We have previously shown that one likely function of the C-terminal domains of OPG is to bind cell surface heparan sulfate (HS), but the in vivo evidence was lacking. To investigate the biological significance of OPG-HS interaction in bone remodeling, we created OPG knock-in mice (opg ^AAA ). The mutated OPG is incapable of binding to HS but binds RANKL normally. Surprisingly, opg ^AAA/AAA mice displayed a severe osteoporotic phenotype that is very similar to opg-null mice, suggesting that the antiresorption activity of OPG requires HS. Mechanistically, we propose that the HS immobilizes secreted OPG at the surface of osteoblasts lineage cells, which facilitates binding of OPG to membrane-anchored RANKL. To further support this model, we altered the structure of osteoblast HS genetically to make it incapable of binding to OPG. Interestingly, osteocalcin-Cre;Hs2st ^f/f mice also displayed osteoporotic phenotype with similar severity to opg ^AAA/AAA mice. Combined, our data provide strong genetic evidence that OPG-HS interaction is indispensable for normal bone homeostasis.

A clinical guide to the pathophysiology, diagnosis and treatment of osteosarcopenia

Advances in medicine have paved the way for older persons to live longer, but with more years spent living with disability and dependency. Many older persons are living with comorbidities such as osteoporosis (loss of bone mass) and sarcopenia (loss of muscle mass and function), two diseases that, when concurrent, form osteosarcopenia, a newly identified musculoskeletal syndrome. Osteosarcopenia impedes mobility and diminishes independence and thus quality of life. Evidence suggests the pathology of this syndrome comprises genetic polymorphisms, alterations in mechanotransduction, and localized or systemic crosstalk between growth factors and other proteins (myokines, osteokines, adipokines). As a direct result of an aging society, health outcomes such as falls and fractures will rise as the prevalence of osteosarcopenia increases. Two major risk factors for osteosarcopenia (other than age itself) are physical inactivity and poor nutrition. Addressing these modifiable risk factors can prevent, or at least delay, the onset of osteosarcopenia. Pharmaceutical treatments for osteosarcopenia are currently unavailable, although research trials are underway. This review provides an update from basic and clinical sciences on the biology, epidemiology (prevalence, risk factors and diagnosis) and treatments for osteosarcopenia, and recommends future research priorities to improve health outcomes for those living with or at risk of osteosarcopenia.

Osteosarcopenia: epidemiology, diagnosis, and treatment-facts and numbers

BACKGROUND

Osteosarcopenia, the presence of osteopenia/osteoporosis and sarcopenia, is an emerging geriatric giant, which poses a serious global health burden.

METHODS AND RESULTS

The prevalence of osteosarcopenia ranges in community-dwelling older adults [5-37% (≥65 years)] with the highest rates observed in those with fractures (low-trauma fracture: ~46%; hip fracture: 17.1-96.3%). Among 2353 community-dwelling adults, risk factors associated with osteosarcopenia include older age [men: 14.3% (60-64 years) to 59.4% (≥75 years); women: 20.3% (60-64 years) to 48.3% (≥75 years), P < 0.05], physical inactivity [inverse relationship: 0.64, 95% confidence interval (CI) 0.46-0.88 (sexes combined)], low body mass index (inverse relationship: men: 0.84, 95% CI 0.81-0.88; women: 0.77, 95% CI 0.74-0.80), and higher fat mass (men: 1.46, 95% CI 1.11-1.92; women: 2.25, 95% CI 1.71-2.95). Among 148 geriatric inpatients, osteosarcopenic individuals demonstrate poorer nutritional status (mini-nutritional assessment scores: 8.50 ± 2.52 points, P < 0.001) vs. osteoporosis or sarcopenia alone, while among 253 older Australians, osteosarcopenia is associated with impaired balance and functional capacity [odds ratios (ORs): 2.56-7.19; P < 0.05] vs. non-osteosarcopenia. Osteosarcopenia also associates with falls (ORs: 2.83-3.63; P < 0.05), fractures (ORs: 3.86-4.38; P < 0.05), and earlier death [hazard ratio (1-year follow-up): 1.84, 95% CI; 0.69-4.92, P = 0.023] vs. non-osteosarcopenia.

CONCLUSIONS

This syndrome is expected to grow in age-related and disease-related states, a likely consequence of immunosenescence coinciding with increased sedentarism, obesity, and fat infiltration of muscle and bone. Evidence suggests the pathophysiology of osteosarcopenia includes genetic polymorphisms, reduced mechanical loading, and impaired endocrine functioning, as well as altered crosstalk between muscle, bone, and fat cells. Clinicians should screen for osteosarcopenia via imaging methods (i.e. dual-energy X-ray absorptiometry) to quantify muscle and bone mass, in addition to assessing muscle strength (i.e. grip strength) and functional capacity (i.e. gait speed). A comprehensive geriatric assessment, including medical history and risk factors, must also be undertaken. Treatment of this syndrome should include osteoporotic drugs [bone anabolics/antiresorptives (i.e. teriparatide, denosumab, bisphosphates)] where indicated, and progressive resistance and balance exercises (at least 2-3 times/week). To maximize musculoskeletal health, nutritional recommendations [protein (1.2-1.5 g/kg/day), vitamin D (800-1000 IU/day), calcium (1300 mg/day), and creatine (3-5 g/day)] must also be met. It is anticipated that diagnosis and treatment for osteosarcopenia will become part of routine healthcare in the future. However, further work is required to identify biomarkers, which, in turn, may increase diagnosis, risk stratification, and targeted treatments to improve health outcomes.

Diabetes and calcification: The potential role of anti-diabetic drugs on vascular calcification regression

Vascular calcification (VC) has been well-established as an independent and strong predictor of cardiovascular diseases (CVD) as well as major cardiac adverse events (MACE). VC is associated with increased mortality in patients with CVD. Pathologically, VC is now believed to be a multi-directional active process ultimately resulting in ectopic calcium deposition in vascular beds. On the other hand, prevalence of diabetes mellitus (DM) is gradually increasing thus making the current population more prone to future CVD. Although the mechanisms involved in development and progression of VC in DM patients are not fully understood, a series of evidences demonstrated positive association between DM and VC. It has been highlighted that different cellular pathways are involved in this process. These intermediates such as tumor necrosis factor alpha (TNF-α), various interleukins (ILs) and different cell-signaling pathways are over-expressed in DM patients leading to development of VC. Thus, considering the burden and significance of VC it is of great importance to find a therapeutic approach to prevent or minimize the development of VC in DM patients. Over the past few years various anti diabetic drugs (ADDs) have been introduced and many of them showed desired glucose control. But no study demonstrated the effects of these medications on regression of VC. In this review, we will briefly discuss the current understanding on DM and VC and how commonly used ADDs modulate the development or progression of VC.

Denosumab in postmenopausal women with osteoporosis and diabetes: Subgroup analysis of FREEDOM and FREEDOM extension

PURPOSE

Diabetes and osteoporosis occur frequently in older adults and are both associated with increased fracture risk. Denosumab treatment reduced new vertebral, nonvertebral, and hip fractures over 3 years, with continued low fracture incidence for up to 10 years in postmenopausal women with osteoporosis. However, its effects in diabetic subjects with osteoporosis have not yet been investigated.

METHODS

Post hoc analysis of the 3-year, placebo-controlled FREEDOM study and 7-year Extension included postmenopausal women with osteoporosis and diabetes. Effects on BMD, vertebral, and nonvertebral fracture incidence were evaluated.

RESULTS

Of 7808 subjects in FREEDOM, 508 with diabetes received denosumab (n = 266) or placebo (n = 242). Among those, BMD increased significantly with denosumab versus placebo in FREEDOM, and continued to increase during the Extension in long-term (continuing denosumab) and crossover (placebo to denosumab) denosumab subjects. In FREEDOM, denosumab-treated subjects with diabetes had significantly lower new vertebral fracture rates (1.6%) versus placebo (8.0%) (RR: 0.20 [95% CI 0.07-0.61]; p = .001). Nonvertebral fracture incidence was higher with denosumab (11.7%) versus placebo (5.9%) (HR: 1.94 [95% CI 1.00-3.77]; p = .046), although there were fewer hip fractures with denosumab (World Health Organization, 2017 [1]) than placebo (4; nonsignificant). During the first 3 years in FREEDOM Extension, new vertebral and nonvertebral fracture incidences were low in long-term and crossover denosumab diabetic groups (≤6%), consistent with the overall Extension population; yearly nonvertebral fracture incidence was comparable to the FREEDOM placebo group.

CONCLUSION

Denosumab significantly increased BMD and decreased vertebral fracture risk in subjects with osteoporosis and diabetes. No reduction in nonvertebral fractures was observed.

Osteosarcopenia: the Path Beyond Controversy

PURPOSE OF REVIEW

Osteosarcopenia is commonly accepted as the presence of low muscle mass and function (sarcopenia) and low bone mineral density (osteopenia and osteoporosis). Osteosarcopenia remains a topic of controversy as researchers worldwide seek to elucidate whether osteosarcopenia is associated with greater risk of negative outcomes than its component parts. This review examines the latest research and controversies, and charts a path forward.

RECENT FINDINGS

Osteosarcopenia may occur in 5-37% of community-dwelling adults over the age of 65. This wide range is driven by variation in population, setting, and definitions applied. These differences in study design have resulted in mixed findings in associations with adverse outcomes for older adults living with osteosarcopenia. Research into interventions to prevent or treat osteosarcopenia, such as exercise, protein supplementation, and pharmacotherapy, is in its infancy but examined herein. The absence of a consensus operational definition of sarcopenia, and inaccurate measures of muscle mass, has hampered global progress in the field. We present a case for the path forward by reflecting on our recent history.

Burn injury and restoration of muscle function

Burn injury in children results in a systemic inflammatory reaction as well as a stress response. Consequences of these non-specific adaptive responses include resorptive bone loss and muscle catabolism. These adverse events can result in a post-burn fracture rate of approximately 15% and long-term muscle weakness that prolongs recovery. A randomized controlled trial of a single dose of the bisphosphonate pamidronate within the first ten days of burn injury resulted in the prevention of resorptive bone loss and continuous bone accrual. Examining the muscle protein kinetics in pediatric burn patients enrolled in that randomized controlled trial revealed that those who had been given the single dose bisphosphonate experienced preservation of muscle mass and strength. An in vitro study of mouse myoblasts incubated with serum from patients who participated in the randomized controlled study demonstrated that mouse myoblasts exposed to serum from patients given the single dose bisphosphonate exhibited greater myotube diameter than those from burned children given placebo. Moreover, the serum from bisphosphonate treated patients stimulated the protein anabolic pathways and suppressed protein catabolic pathways in these cells. Inasmuch as incubation of the myotubes with an antibody to transforming growth factor beta (TGFβ) rescued myotube size in the cultures with serum from patients who received the placebo to the same magnitude as cultures with serum from patients treated with single dose bisphosphonate, we postulate that post-burn bone resorption liberates muscle catabolic factors which cause muscle wasting. Future uses of bisphosphonates could include studies designed to prevent short-term acute bone resorption in conditions that may result in muscle wasting as well as in short-term interventions in chronic inflammatory conditions which may flare and cause acute bone and muscle loss.

Commentary on the effects of receptor activator of nuclear factor-B ligand inhibition on bone mass and muscle strength

The pathophysiology of osteoporosis and sarcopenia.

Bone Control of Muscle Function

Bone and muscle represent a single functional system and are tightly connected to each other. Indeed, diseases characterized by alterations of muscle physiology have effects on bone remodeling and structure and vice versa. Muscle influence on bone has been deeply studied, and recent studies identified irisin as new molecule involved in this crosstalk. Muscle regulation by bone needs to be extensively investigated since in the last few years osteocalcin was recognized as a key molecule in the bone–muscle interaction. Osteocalcin can exist in two forms with different degrees of carboxylation. The undercarboxylated form of osteocalcin is a hormone released by the bone matrix during the osteoclast bone resorption and can bind its G-protein coupled receptor GPRC6A expressed in the muscle, thus regulating its function. Recently, this hormone was described as an antiaging molecule for its ability to regulate bone, muscle and cognitive functions. Indeed, the features of this bone-related hormone were used to test a new therapeutic approach for sarcopenia, since injection of osteocalcin in older mice induces the acquirement of physical abilities of younger animals. Even if this approach should be tested in humans, osteocalcin represents the most surprising molecule in endocrine regulation by the skeleton.

RANKL biology: bone metabolism, the immune system, and beyond

Receptor activator of NF-κB (RANK) ligand (RANKL) induces the differentiation of monocyte/macrophage-lineage cells into the bone-resorbing cells called osteoclasts. Because abnormalities in RANKL, its signaling receptor RANK, or decoy receptor osteoprotegerin (OPG) lead to bone diseases such as osteopetrosis, the RANKL/RANK/OPG system is essential for bone resorption. RANKL was first discovered as a T cell-derived activator of dendritic cells (DCs) and has many functions in the immune system, including organogenesis, cellular development. The essentiality of RANKL in the bone and the immune systems lies at the root of the field of "osteoimmunology." Furthermore, this cytokine functions beyond the domains of bone metabolism and the immune system, e.g., mammary gland and hair follicle formation, body temperature regulation, muscle metabolism, and tumor development. In this review, we will summarize the current understanding of the functions of the RANKL/RANK/OPG system in biological processes.

Identification of osteoclast-osteoblast coupling factors in humans reveals links between bone and energy metabolism

Bone remodeling consists of resorption by osteoclasts followed by formation by osteoblasts, and osteoclasts are a source of bone formation-stimulating factors. Here we utilize osteoclast ablation by denosumab (DMAb) and RNA-sequencing of bone biopsies from postmenopausal women to identify osteoclast-secreted factors suppressed by DMAb. Based on these analyses, LIF, CREG2, CST3, CCBE1, and DPP4 are likely osteoclast-derived coupling factors in humans. Given the role of Dipeptidyl Peptidase-4 (DPP4) in glucose homeostasis, we further demonstrate that DMAb-treated participants have a significant reduction in circulating DPP4 and increase in Glucagon-like peptide (GLP)-1 levels as compared to the placebo-treated group, and also that type 2 diabetic patients treated with DMAb show significant reductions in HbA1c as compared to patients treated either with bisphosphonates or calcium and vitamin D. Thus, our results identify several coupling factors in humans and uncover osteoclast-derived DPP4 as a potential link between bone remodeling and energy metabolism.

Anti-resorptive bone therapies also inhibit bone formation, as osteoclasts secrete factors that stimulate bone formation by osteoblasts. Here, the authors identify osteoclast-secreted factors that couple bone resorption to bone formation in healthy subjects, and show that osteoclast-derived DPP4 may be a factor coupling bone resorption to energy metabolism.

Muscle-Bone Crosstalk in the Masticatory System: From Biomechanical to Molecular Interactions

The masticatory system is a complex and highly organized group of structures, including craniofacial bones (maxillae and mandible), muscles, teeth, joints, and neurovascular elements. While the musculoskeletal structures of the head and neck are known to have a different embryonic origin, morphology, biomechanical demands, and biochemical characteristics than the trunk and limbs, their particular molecular basis and cell biology have been much less explored. In the last decade, the concept of muscle-bone crosstalk has emerged, comprising both the loads generated during muscle contraction and a biochemical component through soluble molecules. Bone cells embedded in the mineralized tissue respond to the biomechanical input by releasing molecular factors that impact the homeostasis of the attaching skeletal muscle. In the same way, muscle-derived factors act as soluble signals that modulate the remodeling process of the underlying bones. This concept of muscle-bone crosstalk at a molecular level is particularly interesting in the mandible, due to its tight anatomical relationship with one of the biggest and strongest masticatory muscles, the masseter. However, despite the close physical and physiological interaction of both tissues for proper functioning, this topic has been poorly addressed. Here we present one of the most detailed reviews of the literature to date regarding the biomechanical and biochemical interaction between muscles and bones of the masticatory system, both during development and in physiological or pathological remodeling processes. Evidence related to how masticatory function shapes the craniofacial bones is discussed, and a proposal presented that the masticatory muscles and craniofacial bones serve as secretory tissues. We furthermore discuss our current findings of myokines-release from masseter muscle in physiological conditions, during functional adaptation or pathology, and their putative role as bone-modulators in the craniofacial system. Finally, we address the physiological implications of the crosstalk between muscles and bones in the masticatory system, analyzing pathologies or clinical procedures in which the alteration of one of them affects the homeostasis of the other. Unveiling the mechanisms of muscle-bone crosstalk in the masticatory system opens broad possibilities for understanding and treating temporomandibular disorders, which severely impair the quality of life, with a high cost for diagnosis and management.

The Interplay Between Bone and Glucose Metabolism

The multiple endocrine functions of bone other than those related to mineral metabolism, such as regulation of insulin sensitivity, glucose homeostasis, and energy metabolism, have recently been discovered. In vitro and murine studies investigated the impact of several molecules derived from osteoblasts and osteocytes on glucose metabolism. In addition, the effect of glucose on bone cells suggested a mutual cross-talk between bone and glucose homeostasis. In humans, these mechanisms are the pivotal determinant of the skeletal fragility associated with both type 1 and type 2 diabetes. Metabolic abnormalities associated with diabetes, such as increase in adipose tissue, reduction of lean mass, effects of hyperglycemia per se, production of the advanced glycation end products, diabetes-associated chronic kidney disease, and perturbation of the calcium-PTH-vitamin D metabolism, are the main mechanisms involved. Finally, there have been multiple reports of antidiabetic drugs affecting the skeleton, with differences among basic and clinical research data, as well as of anti-osteoporosis medication influencing glucose metabolism. This review focuses on the aspects linking glucose and bone metabolism by offering insight into the most recent evidence in humans.

Osteosarcopenia: A case of geroscience

Many older persons lose their mobility and independence due to multiple diseases occurring simultaneously. Geroscience is aimed at developing innovative approaches to better identify relationships among the biological processes of aging. Osteoporosis and sarcopenia are two of the most prevalent chronic diseases in older people, with both conditions sharing overlapping risk factors and pathogenesis. When occurring together, these diseases form a geriatric syndrome termed "osteosarcopenia," which increases the risk of frailty, hospitalizations, and death. Findings from basic and clinical sciences aiming to understand osteosarcopenia have provided evidence of this syndrome as a case of geroscience. Genetic, endocrine, and mechanical stimuli, in addition to fat infiltration, sedentarism, and nutritional deficiencies, affect muscle and bone homeostasis to characterize this syndrome. However, research is in its infancy regarding accurate diagnostic markers and effective treatments with dual effects on muscle and bone. To date, resistance exercise remains the most promising strategy to increase muscle and bone mass, while sufficient quantities of protein, vitamin D, calcium, and creatine may preserve these tissues with aging. More recent findings, from rodent models, suggest treating ectopic fat in muscle and bone marrow as a possible avenue to curb osteosarcopenia, although this needs testing in human clinical trials.

Therapeutic approaches to osteosarcopenia: insights for the clinician

Osteopenia/osteoporosis and sarcopenia are both age-related conditions. Given the well-defined bone and muscle interaction, when osteopenia and sarcopenia occur simultaneously, this geriatric syndrome is defined as ‘osteosarcopenia’. Evidence exists about therapeutic interventions common to both bone and muscle, which could thereby be effective in treating osteosarcopenia. In addition, there are roles for common nonpharmacological strategies such as nutritional intervention and physical exercise prescription in the management of this condition. In this review we summarize the evidence on current and upcoming therapeutic approaches to osteosarcopenia.

Bisphosphonate Treatment Ameliorates Chemotherapy-Induced Bone and Muscle Abnormalities in Young Mice

Chemotherapy is frequently accompanied by several side effects, including nausea, diarrhea, anorexia and fatigue. Evidence from ours and other groups suggests that chemotherapy can also play a major role in causing not only cachexia, but also bone loss. This complicates prognosis and survival among cancer patients, affects quality of life, and can increase morbidity and mortality rates. Recent findings suggest that soluble factors released from resorbing bone directly contribute to loss of muscle mass and function secondary to metastatic cancer. However, it remains unknown whether similar mechanisms also take place following treatments with anticancer drugs. In this study, we found that young male CD2F1 mice (8-week old) treated with the chemotherapeutic agent cisplatin (2.5 mg/kg) presented marked loss of muscle and bone mass. Myotubes exposed to bone conditioned medium from cisplatin-treated mice showed severe atrophy (-33%) suggesting a bone to muscle crosstalk. To test this hypothesis, mice were administered cisplatin in combination with an antiresorptive drug to determine if preservation of bone mass has an effect on muscle mass and strength following chemotherapy treatment. Mice received cisplatin alone or combined with zoledronic acid (ZA; 5 μg/kg), a bisphosphonate routinely used for the treatment of osteoporosis. We found that cisplatin resulted in progressive loss of body weight (-25%), in line with reduced fat (-58%) and lean (-17%) mass. As expected, microCT bone histomorphometry analysis revealed significant reduction in bone mass following administration of chemotherapy, in line with reduced trabecular bone volume (BV/TV) and number (Tb.N), as well as increased trabecular separation (Tb.Sp) in the distal femur. Conversely, trabecular bone was protected when cisplatin was administered in combination with ZA. Interestingly, while the animals exposed to chemotherapy presented significant muscle wasting (~-20% vs. vehicle-treated mice), the administration of ZA in combination with cisplatin resulted in preservation of muscle mass (+12%) and strength (+42%). Altogether, these observations support our hypothesis of bone factors targeting muscle and suggest that pharmacological preservation of bone mass can benefit muscle mass and function following chemotherapy.