Extra-skeletal effects of bisphosphonates

A multifaceted role of bisphosphonates from palliative care to anti-cancer therapy in solid tumors

INTRODUCTION

Bisphosphonates (P-C-Ps) also called diphosphonates are the structural analogs of naturally occurring pyrophosphates. Bisphosphonates are traditionally used and shown to provide long-term success in the treatment and prevention of osteoporosis and other bone loss pathologies. Furthermore, bisphosphonates are gaining popularity in the present era of cancer therapeutics and prevention. The usage of bisphosphonates as adjuvant or neoadjuvant therapy, either as a single agent or combined with other chemotherapy, has been studied in different solid tumors. This review aims to present the various roles of bisphosphonates in solid tumors.

DATA SOURCES

Articles in MEDLINE/PubMed and the National Institutes of Health Clinical Trials Registry (http://www. Clinicaltrials.gov) between 1 January 2011 and 1 February 2022 were extracted using MeSH terms "bisphosphonates/diphosphosphonates and mechanism," "bisphosphonates and breast cancer," "bisphosphonates and prostate cancer," "bisphosphonates and lung cancer," "bisphosphonates and cancer risk," and "bisphosphonates and adverse events." Manual searches of some major oncology journals were also conducted.

DISCUSSION

This review article focuses on the antitumor activity of bisphosphonates, safety profile, and the role of bisphosphonates as preventive, neoadjuvant, and adjuvant chemotherapy. A significant improvement in overall survival and cancer-specific survival and recurrence-free survival with the usage of bisphosphonates is noted in breast cancer patients, particularly in post-menopausal women. Though great progress has been achieved in over 20 years, further research is needed to identify the subgroup of patients that are most likely to benefit from adjuvant bisphosphonate therapy and to determine regimens with greater efficacy and better safety profile.

Type 2 diabetes incidence in patients initiating denosumab or alendronate treatment: a primary care cohort study

Denosumab initiation is related to a lower risk of type 2 diabetes than alendronate in anti-osteoporotic treatment-naïve users in primary care practices.

PURPOSE

Links have been suggested between bone metabolism and glucose tolerance. Downregulation of the receptor activator of nuclear factor κ B ligand (RANKL) signaling improves glucose metabolism. Denosumab, a human monoclonal antibody against RANKL, may be associated with a lower risk of type 2 diabetes (T2D). The aim was to compare incidence rates of T2DM in primary care patients initiating denosumab or alendronate, which is a first-line therapy of osteoporosis. Alendronate as comparator enhances comparability of the two cohorts.

METHOD

The IQVIA Disease Analyzer comprises a representative panel of general and specialist practices (Germany). A new-user comparative study was conducted among patients with denosumab or alendronate treatment (2010-2021) without history of diabetes and age ≥ 45 years. Incidence rates (per 1,000 person-years) and Cox proportional hazard ratios (HR; 95%CI) for T2DM were estimated.

RESULTS

The cohorts consisted of 3,354 denosumab (age: 75 years; women: 87%) and 27,068 alendronate (76 years; 86%) users. Overall, 1,038 persons developed T2D during 54,916 person-years. T2DM incidence rates per 1,000 person-years were 11.9 (9.5-14.4) for denosumab and 20.1 (18.8-21.3) for alendronate users, respectively. Denosumab was associated with a reduced risk of T2DM compared to alendronate, adjusting for age, sex, index year, visits, obesity, comorbidities and statins (HR: 0.73; 0.58-0.89).

CONCLUSION

In this comparative study of older patients seen in routine practices, denosumab was associated with a lower risk of developing T2DM than alendronate.

Generation of BT-Amide, a Bone-Targeted Pyk2 Inhibitor, Effective via Oral Administration, for the Prevention of Glucocorticoid-Induced Bone Loss

Glucocorticoid-induced osteoporosis (GIOP) is the leading cause of iatrogenic osteoporosis due to the widespread clinical use of glucocorticoids (GC) as immunosuppressants. Previous research identified the proline-rich tyrosine kinase 2, Pyk2, as a critical mediator of GC-induced bone loss, and that blocking Pyk2 could protect the skeleton from adverse GC actions. However, systemic administration of current Pyk2 inhibitors causes harmful side effects, such as skin lesions. To address this, we developed bone-targeted (BT) Pyk2 inhibitors by conjugating them with bisphosphonates (BP), ensuring adherence to the bone matrix and reducing impact on noncalcified tissues. We synthesized BT-Amide by linking a derivative of TAE-226, a Pyk2 inhibitor, with alendronic acid. Oral administration (gavage) of BT-Amide prevented GC-induced bone loss in mice without causing skin lesions, or elevation of any organ toxicity markers. These findings introduce BT-Amide as the first orally effective bone-targeted Pyk2 inhibitor for preventing GC-induced bone loss while minimizing off-target effects.

FATP2 regulates osteoclastogenesis by increasing lipid metabolism and ROS production

Lipid metabolism plays a crucial role in maintaining bone homeostasis, particularly in osteoclasts (OCs) formation. Here, we found that the expression level of FATP2, a transporter for long-chain and very-long-chain fatty acids, was significantly upregulated during OC differentiation and in the bone marrow of mice fed a high-fat diet (HFD). Notably, the use of FATP2 siRNA or a specific inhibitor (Lipofermata) resulted in significant inhibition of OC differentiation, while only slightly affecting osteoblasts. In pathological models of bone loss induced by LPS or ovariectomy, in vivo treatment with Lipofermata was able to rescue the loss of bone mass by inhibiting OC differentiation. RNA sequencing revealed that Lipofermata reduced fatty acid β-oxidation and inhibited energy metabolism, while regulating ROS metabolism to decrease ROS production, ultimately inhibiting OC differentiation. Treatment with Lipofermata, either in vivo or in vitro, effectively rescued the overactivation of OCs, indicating that FATP2 regulated OC differentiation by modulating fatty acid uptake and energy metabolism. These findings suggested that targeting FATP2 may represent a promising therapeutic approach for pathological osteoporosis.

Update on current and new potential immunotherapies in breast cancer, from bench to bedside

Impressive advances have been seen in cancer immunotherapy during the last years. Although breast cancer (BC) has been long considered as non-immunogenic, immunotherapy for the treatment of BC is now emerging as a new promising therapeutic approach with considerable potential. This is supported by a plethora of completed and ongoing preclinical and clinical studies in various types of immunotherapies. However, a significant gap between clinical oncology and basic cancer research impairs the understanding of cancer immunology and immunotherapy, hampering cancer therapy research and development. To exploit the accumulating available data in an optimal way, both fundamental mechanisms at play in BC immunotherapy and its clinical pitfalls must be integrated. Then, clinical trials must be critically designed with appropriate combinations of conventional and immunotherapeutic strategies. While there is room for major improvement, this updated review details the immunotherapeutic tools available to date, from bench to bedside, in the hope that this will lead to rethinking and optimizing standards of care for BC patients.

Bone Mineral Density and the Risk of Parkinson's Disease in Postmenopausal Women

BACKGROUND

Whether bone mineral density (BMD) is related to the risk of Parkinson's disease (PD) is unclear.

OBJECTIVES

The objective of this study was to examine the association between BMD status and incident PD in postmenopausal women.

METHODS

We retrospectively examined a nationwide cohort of 272,604 women aged 66 years who participated in the 2009-2012 Korean national health screening for transitional ages. BMD was evaluated using dual-energy X-ray absorptiometry of the central bones. The use of antiosteoporosis medications (AOMs) was assessed. We performed multivariable Cox proportional hazards regression to evaluate the association between BMD and PD risk by calculating hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During the median follow-up of 7.7 years, 2,884 (1.1%) incident PD cases developed. After adjusting for confounding factors, lower BMD was associated with an increased risk of PD (P for trend <0.001). Individuals with osteoporosis had a 1.40-fold higher HR (1.40, 95% CI: 1.25-1.56) than those with a normal BMD. Sensitivity analyses suggested the associations robust to longer lag periods and further adjustment. These associations were prominent in individuals without AOM use before or after enrollment (P for interaction = 0.031 and 0.014). Increased risks of PD in individuals with osteopenia and osteoporosis who did not use AOMs were attenuated by the medication use during the follow-up period, regardless of previous AOM use.

CONCLUSIONS

Lower postmenopausal BMD and osteoporosis were associated with an increased risk of PD. In addition, this association could be mitigated using AOMs. Proper management of BMD in postmenopausal women may help prevent PD. © 2023 International Parkinson and Movement Disorder Society.

Role of denosumab in bone erosions in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic inflammation and synovitis which evolve into joint destruction and deformity. Bone abnormalities are represented by marginal bone erosions and iuxta-articular and generalized osteoporosis. Overactivation of osteoclasts along with dysregulation of osteoblasts are the key events. Bone resorption is mediated by the receptor activator of nuclear factor (NF)-κB (RANK) ligand (RANK-L), responsible for the differentiation, proliferation, and activation of osteoclasts. RANK-L binds its receptor RANK, localized on the surface of preosteoclasts and mature osteoclasts promoting osteoclastogenesis. High levels of RANK-L were demonstrated in active RA patients. Denosumab, a fully human monoclonal antibody, binds RANK-L and suppresses the RANK-RANK-L signaling pathway leading to the inhibition of osteoclastogenesis. A retrospective analysis of published studies such as clinical trials evidenced the efficacy of denosumab in preventing bone erosion progression in RA patients. Key messages Key questions to answer in future include the following: Could denosumab be associated with other biologic therapies in RA patients? Could denosumab block the progression of bone damage in RA? Could denosumab be used for the prevention of bone erosion in RA?

Denosumab and incidence of type 2 diabetes among adults with osteoporosis: population based cohort study

OBJECTIVE

To estimate the effect of denosumab compared with oral bisphosphonates on reducing the risk of type 2 diabetes in adults with osteoporosis.

DESIGN

Population based study involving emulation of a randomized target trial using electronic health records.

SETTING

IQVIA Medical Research Data primary care database in the United Kingdom, 1995-2021.

PARTICIPANTS

Adults aged 45 years or older who used denosumab or an oral bisphosphonate for osteoporosis.

MAIN OUTCOME MEASURES

The primary outcome was incident type 2 diabetes, as defined by diagnostic codes. Cox proportional hazards models were used to estimate adjusted hazard ratios and 95% confidence intervals, comparing denosumab with oral bisphosphonates using an as treated approach.

RESULTS

4301 new users of denosumab were matched on propensity score to 21 038 users of an oral bisphosphonate and followed for a mean of 2.2 years. The incidence rate of type 2 diabetes in denosumab users was 5.7 (95% confidence interval 4.3 to 7.3) per 1000 person years and in oral bisphosphonate users was 8.3 (7.4 to 9.2) per 1000 person years. Initiation of denosumab was associated with a reduced risk of type 2 diabetes (hazard ratio 0.68, 95% confidence interval 0.52 to 0.89). Participants with prediabetes appeared to benefit more from denosumab compared with an oral bisphosphonate (hazard ratio 0.54, 0.35 to 0.82), as did those with a body mass index ≥30 (0.65, 0.40 to 1.06).

CONCLUSIONS

In this population based study, denosumab use was associated with a lower risk of incident type 2 diabetes compared with oral bisphosphonate use in adults with osteoporosis. This study provides evidence at a population level that denosumab may have added benefits for glucose metabolism compared with oral bisphosphonates.

Effects of antiresorptive agents on body composition: a case-control retrospective study

Introduction

Osteoporosis is the most represented metabolic bone disease and is characterized by the reduction of bone mineral density (BMD), exposing patients to high fracture risk and disability. Bisphosphonates (BPs) are the main compounds exploited in treatment of osteoporosis and significantly reduce fracture risk. Sarcopenia is the pathological reduction of muscle masses and strength, and many studies highlighted its co-existence in patients with impaired bone mass. Indeed, the pathological reduction of lean tissue has been linked to a higher risk of falls and, consequently, fractures and disability. Moreover, the pathological reduction of lean tissue seems to share many pathological mechanisms with impaired bone strength and structure; thus, in this context, we decided to conduct a retrospective case-control study aimed at evaluating the effects of BPs on lean mass and body composition.

Material and methods

We enrolled postmenopausal women from our metabolic bone diseases outpatient clinic who underwent at least two consecutive dual-energy X-ray absorptiometry (DXA) examinations concomitantly to the beginning of an antiresorptive agent. The body composition of patients and controls was compared by fat masses, lean masses and android-to-gynoid ratio (A/G ratio).

Results

A total of 64 female subjects were considered for the study: 41 starting a BP and 23 without treatment were used as control. The fat masses and lean masses appeared to be unaffected by BPs. Conversely, A/G ratio was lower in BPs group after 18 months of therapy compared to baseline (p<0,05). From the stratification based on the single BP we failed to highlight any significant difference between the tested variables.

Conclusions

Bisphosphonates treatment did not modify lean tissues, however a significant reduction of A/G ratio in BP group was documented. Thus the BPs seems to act on patients body composition and extra-skeletal tissues but larger prospective studies are needed to evaluate whether these modifications have clinical relevance.

The Rationale for Using Neridronate in Musculoskeletal Disorders: From Metabolic Bone Diseases to Musculoskeletal Pain

Neridronate or ((6-amino-1-hydroxy-1-phosphonohexyl) phosphonic acid) is an amino-bisphosphonate (BP) synthetized in Italy in 1986. Bisphosphonates are molecules with a P-C-P bond in their structure that allows strong and selectively binding to hydroxyapatite (HAP) as well as osteoclasts inhibition through different mechanisms of action. Neridronate was initially used to treat Paget disease of the bone, demonstrating effectiveness in reducing bone turnover markers as well as pain. The interesting molecular properties of neridronate foster its wide use in several other conditions, such as osteogenesis imperfecta, and osteoporosis. Thanks to the unique safety and efficacy profile, neridronate has been used in secondary osteoporosis due to genetic, rheumatic, and oncological diseases, including in pediatric patients. In the last decade, this drug has also been studied in chronic musculoskeletal pain conditions, such as algodystrophy, demonstrating effectiveness in improving extraskeletal outcomes. This review highlights historical and clinical insights about the use of neridronate for metabolic bone disorders and musculoskeletal pain conditions.

Reduced All-Cause Mortality with Bisphosphonates Among Post-Fracture Osteoporosis Patients: A Nationwide Study and Systematic Review

We assessed the survival outcomes associated with real-world bisphosphonate use, stratified by fracture site, type, administration, and duration of treatment, among patients with osteoporosis. A systematic review that incorporates our findings was conducted to provide up-to-date evidence on survival outcomes with bisphosphonate treatment in real-world settings. Patients diagnosed with osteoporosis who had been hospitalized for major fractures were identified from Taiwan's National Health Insurance Research Database 2008-2017 and followed until 2018. There were 24,390 new bisphosphonate users who were classified and compared with 76,725 nonusers of anti-osteoporosis medications in terms of survival outcomes using Cox model analysis. An inverse probability of treatment weighted Cox model and landmark analyses for minimizing immortal time bias were also performed. Bisphosphonate users vs. nonusers had a significantly lower mortality risk, regardless of fracture site (hazard ratios (95% confidence intervals) for patients with any major fracture, hip fracture, and vertebral fracture: 0.90 (0.88, 0.93), 0.83 (0.80, 0.86), and 0.86 (0.82, 0.89), respectively). Compared with nonuse, zoledronic acid (0.77 (0.73, 0.82)) was associated with the lowest mortality, followed by ibandronate (0.85 (0.78, 0.93)) and alendronate/risedronate (0.93 (0.91, 0.96)). Using bisphosphonates for ≥ 3 years had lower mortality (0.60 (0.53, 0.67)) than using bisphosphonates for < 3 years (0.98 (0.95, 1.01)). Intravenous bisphosphonates had a lower mortality than that of oral bisphosphonates. Our results are consistent with the systematic review findings among real-world populations. In conclusion, bisphosphonate use, especially persistence to intravenous bisphosphonates (e.g., zoledronic acid), may reduce post-fracture mortality among patients with osteoporosis, particularly those with hip/vertebral fractures. This supports the rational use of bisphosphonates in post-fracture care.

Alendronate Enhances Functional Recovery after Spinal Cord Injury

Spinal cord injury is a destructive disease characterized by motor/sensory dysfunction and severe inflammation. Alendronate is an anti-inflammatory molecule and may therefore be of benefit in the treatment of the inflammation associated with spinal cord injury. This study aimed to evaluate whether alendronate attenuates motor/sensory dysfunction and the inflammatory response in a thoracic spinal cord clip injury model. Alendronate was intraperitoneally administered at 1 mg/kg/day or 5 mg/kg/day from day (D) 0 to 28 post-injury (PI). The histopathological evaluation showed an alleviation of the inflammatory response, including the infiltration of inflammatory cells, and a decrease in gliosis. Alendronate also led to reductions in the levels of inflammation-related molecules, including mitogen-activated protein kinase, p53, pro-inflammatory cytokines, and pro-inflammatory mediators. Neuro-behavioral assessments, including the Basso, Beattie, and Bresnahan scale for locomotor function, the von Frey filament test, the hot plate test, and the cold stimulation test for sensory function, and the horizontal ladder test for sensorimotor function improved significantly in the alendronate-treated group at D28PI. Taken together, these results suggest that alendronate treatment can inhibit the inflammatory response in spinal cord injury thus improving functional responses.

The effects of metformin and alendronate in attenuating bone loss and improving glucose metabolism in diabetes mellitus mice

Background: To explore the anti-osteoporosis and anti-diabetes effects and potential underlying mechanisms of treatment with metformin and alendronate in diabetes mellitus mice.

Methods: Eight-week-old C57 BL/KS db/db and db/+ female mice were evaluated according to the following treatment group for 12 weeks: control group, diabetes mellitus group, diabetes mellitus with metformin group, diabetes mellitus with Alendronate group, diabetes mellitus with metformin plus alendronate group. Glucose level, glucose tolerance test, bone mineral density, bone microarchitecture, bone histomorphometry, serum biomarkers, and qPCR analysis.

Results: Combined metformin and alendronate can improve progression in glucose metabolism and bone metabolism, including blood glucose levels, blood glucose levels after 4 and 16 hours fasting, glucose tolerance test results, insulin sensitivity and reduces bone loss than the diabetes group. The use of alendronate alone can increase significantly serum glucagon-like peptide-1 levels than the diabetes group. The use of metformin alone can improve bone microstructure such as Tb.Sp and Tb.N of spine in diabetic mice.

Conclusion: The combined use of alendronate and metformin has an anti-diabetes and anti-osteoporotic effect compared with diabetic mice, but they appear to act no obvious synergistically between alendronate and metformin.

Systemic effects of abnormal bone resorption on muscle, metabolism, and cognition

Skeletal tissue is dynamic, undergoing constant remodeling to maintain musculoskeletal integrity and balance in the human body. Recent evidence shows that apart from maintaining homeostasis in the local microenvironment, the skeleton systemically affects other tissues. Several cancer-associated and noncancer-associated bone disorders can disrupt the physiological homeostasis locally in the bone microenvironment and indirectly contribute to dysregulation of systemic body function. The systemic effects of bone on the regulation of distant organ function have not been widely explored. Recent evidence suggests that bone can interact with skeletal muscle, pancreas, and brain by releasing factors from mineralized bone matrix. Currently available bone-targeting therapies such as bisphosphonates and denosumab inhibit bone resorption, decrease morbidity associated with bone destruction, and improve survival. Bisphosphonates have been a standard treatment for bone metastases, osteoporosis, and cancer treatment-induced bone diseases. The extraskeletal effects of bisphosphonates on inhibition of tumor growth are known. However, our knowledge of the effects of bisphosphonates on muscle weakness, hyperglycemia, and cognitive defects is currently evolving. To be able to identify the molecular link between bone and distant organs during abnormal bone resorption and then treat these abnormalities and prevent their systemic effects could improve survival benefits. The current review highlights the link between bone resorption and its systemic effects on muscle, pancreas, and brain.

Therapeutic Options in the Management of Aromatase Inhibitor-Associated Bone Loss

BACKGROUND

Breast cancer is the most commonly occurring cancer in women worldwide. Early breast cancer is a kind of invasive neoplasm that has not proliferated beyond the breast or the axillary lymph nodes. Current therapeutic strategies for breast cancer mainly include local therapies such as surgery or radiotherapy and systemic therapies like chemotherapy, endocrine, and targeted therapy.Nowadays, the adjuvant treatment for hormone receptor-positive early breast cancer in postmenopausal women remains the main effective systemic therapy which can improve disease-free survival and overall survival; it involves several endocrine treatment regimens including selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs), or a combination of them. AIs have been shown to be more effective in preventing recurrence in postmenopausal women with early breast cancer when compared with tamoxifen, thus representing the standard of care for adjuvant endocrine therapy. Although AIs are usually well-tolerated, they can have some side effects. Apart from the appearance of arthralgias or myalgias and cardiovascular events, AI therapies, reducing already low endogenous postmenopausal estradiol levels, cause increased bone loss and increase fracture risk in postmenopausal women.

OBJECTIVES

To evaluate the therapeutic options in the management of aromatase inhibitor-associated bone loss (AIBL).

METHODS

We reviewed the current literature dealing with different therapeutic options in the treatment of AIBL.

RESULTS

Clinical practice guidelines recommend a careful evaluation of skeletal health in all women with breast cancer before AI therapy initiation. Adequate calcium and vitamin D intake have also been suggested. Pharmacological attempts to minimize AI-related bone loss have focused on the use of antiresorptive agents, such as bisphosphonates and denosumab, to protect bone integrity and reduce the risk of fractures. Furthermore, clinical trials have shown that by making the bone microenvironment less susceptible to breast cancer metastasis, these drugs are able to increase disease-free survival.

CONCLUSIONS

AI, thatare the pillar of the systemic treatment for patients with hormone receptor-positive breast cancer, are associated with different side effects, and in particular osteoporosis and fractures. Both bisphosphonates and denosumab are able to prevent this negative effect.

A Novel Small Molecule Neurotrophin-3 Analogue Promotes Inner Ear Neurite Outgrowth and Synaptogenesis In vitro

Sensorineural hearing loss is irreversible and is associated with the loss of spiral ganglion neurons (SGNs) and sensory hair cells within the inner ear. Improving spiral ganglion neuron (SGN) survival, neurite outgrowth, and synaptogenesis could lead to significant gains for hearing-impaired patients. There has therefore been intense interest in the use of neurotrophic factors in the inner ear to promote both survival of SGNs and re-wiring of sensory hair cells by surviving SGNs. Neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDNF) represent the primary neurotrophins in the inner ear during development and throughout adulthood, and have demonstrated potential for SGN survival and neurite outgrowth. We have pioneered a hybrid molecule approach to maximize SGN stimulation in vivo, in which small molecule analogues of neurotrophins are linked to bisphosphonates, which in turn bind to cochlear bone. We have previously shown that a small molecule BDNF analogue coupled to risedronate binds to bone matrix and promotes SGN neurite outgrowth and synaptogenesis in vitro. Because NT-3 has been shown in a variety of contexts to have a greater regenerative capacity in the cochlea than BDNF, we sought to develop a similar approach for NT-3. 1Aa is a small molecule analogue of NT-3 that has been shown to activate cells through TrkC, the NT-3 receptor, although its activity on SGNs has not previously been described. Herein we describe the design and synthesis of 1Aa and a covalent conjugate of 1Aa with risedronate, Ris-1Aa. We demonstrate that both 1Aa and Ris-1Aa stimulate neurite outgrowth in SGN cultures at a significantly higher level compared to controls. Ris-1Aa maintained its neurotrophic activity when bound to hydroxyapatite, the primary mineral component of bone. Both 1Aa and Ris-1Aa promote significant synaptic regeneration in cochlear explant cultures, and both 1Aa and Ris-1Aa appear to act at least partly through TrkC. Our results provide the first evidence that a small molecule analogue of NT-3 can stimulate SGNs and promote regeneration of synapses between SGNs and inner hair cells. Our findings support the promise of hydroxyapatite-targeting bisphosphonate conjugation as a novel strategy to deliver neurotrophic agents to SGNs encased within cochlear bone.

Targeting Small GTPases and Their Prenylation in Diabetes Mellitus

A fundamental role of pancreatic β-cells to maintain proper blood glucose level is controlled by the Ras superfamily of small GTPases that undergo post-translational modifications, including prenylation. This covalent attachment with either a farnesyl or a geranylgeranyl group controls their localization, activity, and protein–protein interactions. Small GTPases are critical in maintaining glucose homeostasis acting in the pancreas and metabolically active tissues such as skeletal muscles, liver, or adipocytes. Hyperglycemia-induced upregulation of small GTPases suggests that inhibition of these pathways deserves to be considered as a potential therapeutic approach in treating T2D. This Perspective presents how inhibition of various points in the mevalonate pathway might affect protein prenylation and functioning of diabetes-affected tissues and contribute to chronic inflammation involved in diabetes mellitus (T2D) development. We also demonstrate the currently available molecular tools to decipher the mechanisms linking the mevalonate pathway’s enzymes and GTPases with diabetes.

Bisphosphonates in inflammatory rheumatic diseases

The main well recognized action of bisphosphonates (BPs) is their antiresorptive capacity, making them first-line drugs in the treatment of osteoporosis and other metabolic bone diseases. In this review we have compiled other possible actions of BPs, particularly in the areas of immunomodulation, anti-inflammatory capacity and in the prevention of structural joint damage in inflammatory rheumatic diseases. The immunomodulatory capacity of BPs has been focused on the mechanisms involved in the acute-phase response associated with the administration of nitrogen containing BPs (N-BPs), with the stimulus of pro-inflammatory cytokines, through the mevalonate pathway, activation of T-cells and the decrease in the cytotoxic T-lymphocyte antigen-4 (CTLA-4). In relation to their anti-inflammatory capacity, special attention has been given to their effect on preventing structural damage in inflammatory joint diseases and on the differential immune response in bone lesions of the most common and representative inflammatory rheumatic diseases, i.e. rheumatoid arthritis and spondyloarthropathies. The present data indicate that more studies are needed to improve the knowledge on the effect of BPs on inflammatory-mediated diseases and particularly on the prevention and/or treatment of the structural damage in these disorders, since these agents could be a potential useful concomitant therapy.

Bisphosphonates, Old Friends of Bones and New Trends in Clinics

Bisphosphonates, used for a long time in osteoporosis management, are currently the target of intensive research, from pre-formulation studies to more advanced stages of clinical practice. This review presents an overview of the contributions of this family of compounds to human health, starting with the chemistry and clinical uses of bisphosphonates. Following this, their pharmacology is described, highlighting administration-borne handicaps and undesirable effects. The last three sections of the review describe the research efforts that seek to curb delivery-related issues and expand bisphosphonate use. Innovative routes and strategies of administration, such as nano-encapsulation for oral intake or injectable cements for local or in-bone delivery are presented, as well as the latest results of case studies or preclinical studies proposing new therapeutic indications for the clinically approved bisphosphonates. Finally, a selection of anti-infectious bisphosphonate new drug candidates is shown, with focus on the molecules reported in the last two decades.