Abstract
The nitrogen-containing bisphosphonates (N-BPs), alendronate and risedronate, are the only pharmacologic agents shown to prevent spine and nonvertebral fractures associated with postmenopausal and glucocorticoid-induced osteoporosis. At the tissue level, this is achieved through osteoclast inhibition, which leads to reduced bone turnover, increased bone mass, and improved mineralization. The molecular targets of bisphosphonates (BPs) have recently been identified. This review will discuss the mechanism of action of BPs, focusing on alendronate and risedronate, which are the two agents most widely studied. They act on the cholesterol biosynthesis pathway enzyme, farnesyl diphosphate synthase. By inhibiting this enzyme in the osteoclast, they interfere with geranylgeranylation (attachment of the lipid to regulatory proteins), which causes osteoclast inactivation. This mechanism is responsible for N-BP suppression of osteoclastic bone resorption and reduction of bone turnover, which leads to fracture prevention.
Similar content being viewed by others
References and Recommended Reading
Boyce RW, Wronski TJ, Ebert DC, et al.: Direct stereological estimation of three-dimensional connectivity in rat vertebrae: effect of estrogen, etidronate and risedronate following ovariectomy. Bone 1995, 16:209–213.
Meunier PJ, Boivin G: Bone mineral density reflects bone mass but also the degree of mineralization of bone: therapeutic implications. Bone 1997, 21:373–377.
Boivin GY, Chavassieux PM, Santora AC, et al.: Alendronate increases bone strength by increasing the mean degree of mineralization of bone tissue in osteoporotic women. Bone 2000, 27:687–694. This clinical study demonstrates enhanced bone mineralization in biopsies of patients treated with alendronate for 2 to 3 years, provides mechanistic insight into the relationship between reduced turnover and prolonged secondary mineralization, leading to greater mean degree of mineralization, and provides a link between tissue-level mechanism on bone and anti-fracture efficacy.
Roschger P, Rinnerthaler S, Yates J, et al.: Alendronate increases degree and uniformity of mineralization in cancellous bone and decreases the porosity in cortical bone of osteoporotic women. Bone 2001, 29:185–191. This clinical study demonstrates enhanced mineralization and reduced porosity in biopsies of patients treated with alendronate for 2 to 3 years. Study demonstrates more uniform mineralization in treated bone, with maintenance of normal crystal structures.
Tonino RP, Meunier PJ, Emkey R, et al.: Skeletal benefits of alendronate: 7-year treatment of postmenopausal osteoporotic women. Phase III Osteoporosis Treatment Study Group. J Clin Endocrinol Metab 2000, 85:3109–3115.
Sato M, Grasser W, Endo N, et al.: Bisphosphonate action: alendronate localization in rat bone and effects on osteoclast ultrastructure. J Clin Invest 1991, 88:2095–2105.
Azuma Y, Sato H, Oue Y, et al.: Alendronate distributed on bone surfaces inhibits osteoclastic bone resorption in vitro and in experimental hypercalcemia models. Bone 1995, 16:235–245.
Masarachia P, Weinreb M, Balena R, Rodan GA: Comparison of the distribution of 3H-alendronate and 3H-etidronate in rat and mouse bones. Bone 2003, 19:281–290.
Schmidt A, Rutledge SJ, Endo N, et al.: Protein-tyrosine phosphatase activity regulates osteoclast formation and function: inhibition by alendronate. Proc Natl Acad Sci U S A 2003, 93:3068–3073.
Endo N, Rutledge SJ, Opas EE, et al.: Human protein tyrosine phosphatase-sigma: alternative splicing and inhibition by bisphosphonates. J Bone Miner Res 2003, 11:535–543.
Murakami H, Takahashi N, Tanaka S, et al.: Tiludronate inhibits protein tyrosine phosphatase activity in osteoclasts. Bone 1997, 20:399–404.
Opas EE, Rutledge SJ, Golub E, et al.: Alendronate inhibition of protein-tyrosine-phosphatase-meg1. Biochem Pharmacol 1997, 54:721–727.
Skorey K, Ly HD, Kelly J, et al.: How does alendronate inhibit protein-tyrosine phosphatases? J Biol Chem 1997, 272:22472–22480.
David P, Nguyen H, Barbier A, Baron R: The bisphosphonate tiludronate is a potent inhibitor of the osteoclast vacuolar H(+)-ATPase. J Bone Miner Res 2003, 11:1498–1507.
Frith JC, Monkkonen J, Blackburn GM, et al.: Clodronate and liposome-encapsulated clodronate are metabolized to a toxic ATP analog, adenosine 5’-(beta, gamma-dichloromethylene) triphosphate, by mammalian cells in vitro. J Bone Miner Res 1997, 12:1358–1367.
Frith JC, Monkkonen J, Auriola S, et al.: The molecular mechanism of action of the antiresorptive and anti-inflammatory drug clodronate: evidence for the formation in vivo of a metabolite that inhibits bone resorption and causes osteoclast and macrophage apoptosis. Arthritis Rheum 2001, 44:2201–2210. This study provides first in vivo evidence for the formation of the active metabolite responsible for clodronate induction osteoclast apoptosis. The active metabolite is shown to induce osteoclast apoptosis and suppress bone resorption, linking its action to that of clodronate.
Lehenkari PP, Kellinsalmi M, Napankangas JP, et al.: Further insight into mechanism of action of clodronate: inhibition of mitochondrial ADP/ATP translocase by a nonhydrolyzable, adenine-containing metabolite. Mol Pharmacol 2002, 61:1255–1262. This biochemical study identifies a likely candidate enzyme, mitochondrial ADT/ATP translocase, as a target for the clodronate metabolite. This provides a link between the moelcular target of clodronate action and the induction of osteoclast apoptosis.
Biller SA, Forster C, Gordon EM, et al.: Isoprenoid (phosphinylmethyl) phosphonates as inhibitors of squalene synthetase. J Med Chem 1988, 31:1869–1871.
Amin D, Cornell SA, Gustafson SK, et al.: Bisphosphonates used for the treatment of bone disorders inhibit squalene synthase and cholesterol biosynthesis. J Lipid Res 1992, 33:1657–1663.
Ciosek CP, Jr, Magnin DR, Harrity TW, et al.: Lipophilic 1,1-bisphosphonates are potent squalene synthase inhibitors and orally active cholesterol lowering agents in vivo. J Biol Chem 1993, 268:24832–24837.
Magnin DR, Biller SA, Dickson JK, Jr, et al.: 1,1-Bisphosphonate squalene synthase inhibitors: interplay between the isoprenoid subunit and the diphosphate surrogate. J Med Chem 1995, 38:2596–2605.
Amin D, Cornell SA, Perrone MH, Bilder GE: 1-Hydroxy-3-(methylpentylamino)-propylidene-1,1-bisphosphonic acid as a potent inhibitor of squalene synthase. Arzneimittelforschung 2003, 46:759–762.
Frolik CA, Bryant HU, Black EC, et al.: Time-dependent changes in biochemical bone markers and serum cholesterol in ovariectomized rats: effects of raloxifene HCl, tamoxifen, estrogen, and alendronate. Bone 2003, 18:621–627.
Berkhout TA, Simon HM, Jackson B, et al.: SR-12813 lowers plasma cholesterol in beagle dogs by decreasing cholesterol biosynthesis. Atherosclerosis 1997, 133:203–212.
Berkhout TA, Simon HM, Patel DD, et al.: The novel cholesterol- lowering drug SR-12813 inhibits cholesterol synthesis via an increased degradation of 3-hydroxy-3-methylglutarylcoenzyme A reductase. J Biol Chem 2003, 271:14376–14382.
Risser F, Pfister CU, Degen PH: An enzyme inhibition assay for the quantitative determination of the new bisphosphonate zoledronate in plasma. J Pharm Biomed Anal 1997, 15:1877–1880.
Bergstrom JD, Bostedor RG, Masarachia PJ, et al.: Alendronate is a specific, nanomolar inhibitor of farnesyl diphosphate synthase. Arch Biochem Biophys 2000, 373:231–241. This biochemical study explains how farnesyl diphosphate synthase was first identified as the molecular target for N-BPs.
van Beek E, Pieterman E, Cohen L, et al.: Nitrogen-containing bisphosphonates inhibit isopentenyl pyrophosphate isomerase/farnesyl pyrophosphate synthase activity with relative potencies corresponding to their antiresorptive potencies in vitro and in vivo. Biochem Biophys Res Commun 1999, 255:491–494.
van Beek E, Pieterman E, Cohen L, et al.: Farnesyl pyrophosphate synthase is the molecular target of nitrogen-containing bisphosphonates. Biochem Biophys Res Commun 1999, 264:108–111.
Dunford JE, Thompson K, Coxon FP, et al.: Structure-activity relationships for inhibition of farnesyl diphosphate synthase in vitro and inhibition of bone resorption in vivo by nitrogen-containing bisphosphonates. J Pharmacol Exp Ther 2001, 296:235–242. This biochemical study extends analysis of farnesyl diphosphate synthase inhibition to several N-BPs. It provides statistical evidence for a link between inhibition of this enzyme and in vivo efficacy on bone.
Martin MB, Arnold W, Heath HT, et al.: Nitrogen-containing bisphosphonates as carbocation transition state analogs for isoprenoid biosynthesis. Biochem Biophys Res Commun 1999, 263:754–758.
Ebetino FH, Rogers MJ, Dunford JE, et al.: Modeling of bisphosphonate binding to farnesyl diphosphate synthase. Bone 2002, 30:40S.
Dunford JE, Ebetino FH, Rogers MJ: The mechanism of inhibition of farnesyl diphosphate synthase by nitrogen-containing bisphosphonates. Bone 2002, 30:40S.
Coxon FP, Helfrich MH, Larijani B, et al.: Identification of a novel phosphonocarboxylate inhibitor of Rab geranylgeranyl transferase that specifically prevents Rab prenylation in osteoclasts and macrophages. J Biol Chem 2001, 276:48213–48222.
van Beek ER, Lowik CW, Ebetino FH, Papapoulos SE: Binding and antiresorptive properties of heterocycle-containing bisphosphonate analogs: structure-activity relationships. Bone 1998, 23:437–442.
Green JR, Muller K, Jaeggi KA: Preclinical pharmacology of CGP 42’446, a new, potent, heterocyclic bisphosphonate compound. J Bone Miner Res 1994, 9:745–751.
Rosen LS, Gordon D, Antonio BS, et al.: Zoledronic acid versus pamidronate in the treatment of skeletal metastases in patients with breast cancer or osteolytic lesions of multiple myeloma: a phase III, double-blind, comparative trial. Cancer J 2001, 7:377–387.
Bone HG, Downs RW, Jr, Tucci JR, et al.: Dose-response relationships for alendronate treatment in osteoporotic elderly women. Alendronate Elderly Osteoporosis Study Centers. J Clin Endocrinol Metab 1997, 82:265–274.
Fogelman I, Ribot C, Smith R, et al.: Risedronate reverses bone loss in postmenopausal women with low bone mass: Results from a multinational, double-blind, placebo-controlled trial. J Clin Endocrinol Metab 2000, 85:1895–1900.
Nancollas GH, Mangood AH, Gaafar EM, et al.: Mineral binding affinities of bisphosphonates. Bone 2002, 30:42S.
Zhang FL, Casey PJ: Protein prenylation: molecular mechanisms and functional consequences. Annu Rev Biochem 2003, 65:241–269.
Sinensky M: Recent advances in the study of prenylated proteins. Biochim Biophys Acta 2000, 1484:93–106.
Ridley AJ, Hall A: The small GTP-binding protein Rho regulates the assembly of focal adhesions and actin stress fibers in response to growth factors. Cell 1992, 70:389–399.
Ridley AJ, Paterson HF, Johnston CL, et al.: The small GTPbinding protein rac regulates growth factor-induced membrane ruffling. Cell 1992, 70:401–410.
Zhang D, Udagawa N, Nakamura I, et al.: The small GTP-binding protein, rho p21, is involved in bone resorption by regulating cytoskeletal organization in osteoclasts. J Cell Sci 1995, 108:2285–2292.
Clark EA, King WG, Brugge JS, et al.: Integrin-mediated signals regulated by members of the rho family of GTPases. J Cell Biol 1998, 142:573–586.
Luckman SP, Hughes DE, Coxon FP, et al.: Nitrogen-containing bisphosphonates inhibit the mevalonate pathway and prevent post-translational prenylation of GTP-binding proteins, including Ras. J Bone Miner Res 1998, 13:581–589.
Sato M, Grasser W: Effects of bisphosphonates on isolated rat osteoclasts as examined by reflected light microscopy. J Bone Miner Res 1990, 5:31–40.
Carano A, Teitelbaum SL, Konsek JD, et al.: Bisphosphonates directly inhibit the bone resorption activity of isolated avian osteoclasts in vitro. J Clin Invest 1990, 85:456–461.
Breuil V, Cosman F, Stein L, et al.: Human osteoclast formation and activity in vitro: effects of alendronate. J Bone Miner Res 1998, 13:1721–1729.
Coxon FP, Helfrich MH, Van’t Hof R, et al.: Protein geranylgeranylation is required for osteoclast formation, function, and survival: inhibition by bisphosphonates and GGTI-298. J Bone Miner Res 2000, 15:1467–1476.
Fisher JE, Rodan GA, Reszka AA: In vivo effects of bisphosphonates on the osteoclast mevalonate pathway. Endocrinology 2000, 141:4793–4796. This study provides the first in vivo evidence for the action of N-BPs in targeting the mevalonate pathway. Nitrogen-containing bisphosphonates are shown to target this biosynthetic pathway, alter osteoclast morphology, and increase osteoclast number. Non-BPs share none of these responses and non-significantly reduce osteoclast number.
Singer II, Scott S, Kazazis DM, Huff JW: Lovastatin, an inhibitor of cholesterol synthesis, induces hydroxymethylglutarylcoenzyme A reductase directly on membranes of expanded smooth endoplasmic reticulum in rat hepatocytes. Proc Natl Acad Sci U S A 1988, 85:5264–5268.
Fisher JE, Rogers MJ, Halasy JM, et al.: Alendronate mechanism of action: geranylgeraniol, an intermediate in the mevalonate pathway, prevents inhibition of osteoclast formation, bone resorption, and kinase activation in vitro. Proc Natl Acad Sci U S A 1999, 96:133–138. This cell-biology study provided the first evidence that restoring protein geranylgeranylation prevents alendronate suppression of osteoclast formation and bone resorption. This study focussed the search for molecular target to a small number of candidate enzymes, including farnesyl diphosphate, which was ultimately identified as the molecular target.
van Beek E, Lowik C, van der Pluijm G, Papapoulos S: The role of geranylgeranylation in bone resorption and its suppression by bisphosphonates in fetal bone explants in vitro: A clue to the mechanism of action of nitrogen-containing bisphosphonates. J Bone Miner Res 1999, 14:722–729.
Reszka AA, Halasy Nagy JM, Masarachia PJ, Rodan GA: Bisphosphonates act directly on the osteoclast to induce caspase cleavage of mst1 kinase during apoptosis: a link between inhibition of the mevalonate pathway and regulation of an apoptosis-promoting kinase. J Biol Chem 1999, 274:34967–34973.
Halasy Nagy JM, Rodan GA, Reszka AA: Inhibition of bone resorption by alendronate and risedronate does not require osteoclast apoptosis. Bone 2001, 29:553–559. This study demonstrates that the N-BPs, alendronate and risedronate, act to suppress osteoclast function through nontoxic (non-apoptotic) mechanism. In contrast, the non-bisphosphonates, clodronate and etidronate, are shown to act primarily via induction of apoptosis.
Rogers HL, Marshall D, Rogers MJ: Effects of bisphosphonates on osteoclasts in vitro, studies by scanning electron microscopy. Bone 2002, 30:43S.
Alakangas A, Selander K, Mulari M, et al.: Alendronate disturbs vesicular trafficking in osteoclasts. Calcif Tissue Int 2002, 70:40–47.
Hughes DE, Wright KR, Uy HL, et al.: Bisphosphonates promote apoptosis in murine osteoclasts in vitro and in vivo. J Bone Miner Res 1995, 10:1478–1487.
Coxon FP, Benford HL, Russell RG, Rogers MJ: Protein synthesis is required for caspase activation and induction of apoptosis by bisphosphonate drugs. Mol Pharmacol 1998, 54:631–638.
Luckman SP, Coxon FP, Ebetino FH, et al.: Heterocycle-containing bisphosphonates cause apoptosis and inhibit bone resorption by preventing protein prenylation: evidence from structure-activity relationships in J774 macrophages. J Bone Miner Res 1998, 13:1668–1678.
Shipman CM, Croucher PI, Russell RG, et al.: The bisphosphonate incadronate (YM175) causes apoptosis of human myeloma cells in vitro by inhibiting the mevalonate pathway. Cancer Res 1998, 58:5294–5297.
Benford HL, Frith JC, Auriola S, et al.: Farnesol and geranylgeraniol prevent activation of caspases by aminobisphosphonates: biochemical evidence for two distinct pharmacological classes of bisphosphonate drugs. Mol Pharmacol 1999, 56:131–140.
Glantschnig H, Rodan GA, Reszka AA: Alendronate mechanism of action: the role of geranylgeranylation in p70S6 kinase-dependent osteoclast survival. Bone 2002, 30:41S.
Graves JD, Draves KE, Gotoh Y, et al.: Both phosphorylation and caspase-mediated cleavage contribute to regulation of the Ste20-like protein kinase Mst1 during CD95/Fas-induced apoptosis. J Biol Chem 2001, 276:14909–14915.
Graves JD, Gotoh Y, Draves KE, et al.: Caspase-mediated activation and induction of apoptosis by the mammalian Ste20- like kinase Mst1. EMBO J 1998, 17:2224–2234.
Lee KK, Ohyama T, Yajima N, et al.: MST, a physiological caspase substrate, highly sensitizes apoptosis both upstream and downstream of caspase activation. J Biol Chem 2001, 276:19276–19285.
Schenk R, Merz WA, Muhlbauer R, et al.: Effect of ethane-1- hydroxy-1,1-diphosphonate (EHDP) and dichloromethylene diphosphonate (Cl 2 MDP) on the calcification and resorption of cartilage and bone in the tibial epiphysis and metaphysis of rats. Calcif Tissue Res 1973, 11:196–214.
Selander K, Lehenkari P, Vaananen HK: The effects of bisphosphonates on the resorption cycle of isolated osteoclasts. Calcif Tissue Int 1994, 55:368–375.
Murakami H, Takahashi N, Sasaki T, et al.: A possible mechanism of the specific action of bisphosphonates on osteoclasts: tiludronate preferentially affects polarized osteoclasts having ruffled borders. Bone 1995, 17:137–144.
Seedor JG, Quartuccio HA, Thompson DD: The bisphosphonate alendronate (MK-217) inhibits bone loss due to ovariectomy in rats. J Bone Miner Res 1991, 6:339–346.
Bikle DD, Morey Holton ER, Doty SB, et al.: Alendronate increases skeletal mass of growing rats during unloading by inhibiting resorption of calcified cartilage. J Bone Miner Res 1994, 9:1777–1787.
Lanza F, Schwartz H, Sahba B, et al.: An endoscopic comparison of the effects of alendronate and risedronate on upper gastrointestinal mucosae. Am J Gastroenterol 2000, 95:3112–3117.
Lanza FL, Hunt RH, Thomson AB, et al.: Endoscopic comparison of esophageal and gastroduodenal effects of risedronate and alendronate in postmenopausal women. Gastroenterology 2000, 119:631–638.
de Groen PC, Lubbe DF, Hirsch LJ, et al.: Esophagitis associated with the use of alendronate. N Engl J Med 2003, 335:1016–1021.
Blank MA, Ems BL, Gibson GW, et al.: Nonclinical model for assessing gastric effects of bisphosphonates. Dig Dis Sci 1997, 42:281–288.
Elliott SN, McKnight W, Davies NM, et al.: Alendronate induces gastric injury and delays ulcer healing in rodents. Life Sci 1998, 62:77–91.
Peter CP, Kindt MV, Majka JA: Comparative study of potential for bisphosphonates to damage gastric mucosa of rats [see comments]. Dig Dis Sci 1998, 43:1009–1015.
Reszka AA, Fisher JE, Rodan GA: Mechanism-based local irritation by nitrogen-bisphosphonates. Bone 2001, 28:S95.
Reszka AA, Halasy-Nagy J, Rodan GA: Nitrogen-bisphosphonates block retinoblastoma phosphorylation and cell growth by inhibiting the cholesterol biosynthetic pathway in a keratinocyte model for esophageal irritation. Mol Pharmacol 2001, 59:193–202. This study provides strong evidence that upper gastrointestinal irritation by N-BPs is mediated through their inhibition of farnesyl diphosphate synthase. Growth of primary human keratinocytes, used as a model for the esophageal lining, is suppressed by N-BPs, and effects are linked to suppression of the mevalonate pathway. The data suggest that development of more potent agents may not improve upper gastrointestinal irritation within this class of bisphosphonates (nitrogen-containing).
Suri S, Monkkonen J, Taskinen M, et al.: Nitrogen-containing bisphosphonates induce apoptosis of Caco-2 cells in vitro by inhibiting the mevalonate pathway: a model of bisphosphonate- induced gastrointestinal toxicity. Bone 2001, 29:336–343. This study provides strong evidence that gastrointestinal irriation by the N-BPs is mediated through their inhibition of farnesyl diphosphate synthase. Colon adenocarcinoma cell line intestinal cells show reduced growth and viability after exposure to N-BPs, and effects are linked to suppression of the mevalonate pathway.
Fisher JE, Rodan GA, Reszka AA: Evidence for mechanismbased irritant effects of nitrogen-bisphosphonates on soft tissues. J Bone Miner Res 2001, 16:S218.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Reszka, A.A., Rodan, G.A. Bisphosphonate mechanism of action. Curr Rheumatol Rep 5, 65–74 (2003). https://doi.org/10.1007/s11926-003-0085-6
Issue Date:
DOI: https://doi.org/10.1007/s11926-003-0085-6