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Bocchi MB, Giuli C, Farine F, Ravaioli C, Martellini S, Farsetti P, Palmacci O. Pathological Fractures in Patients Affected by Pycnodysostosis: A Case Series. J Clin Med 2024; 13:2522. [PMID: 38731051 PMCID: PMC11084355 DOI: 10.3390/jcm13092522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/16/2024] [Accepted: 04/20/2024] [Indexed: 05/13/2024] Open
Abstract
Background/Objectives: Pycnodysostosis is a rare genetic disorder causing skeletal dysplasia. It is determined by a gene mutation leading to cathepsin K deficiency and predisposes a patient to osteosclerosis, resulting in increased bone fragility. The altered bone quality typical of this disease is responsible for an increased risk of fractures. The purpose of our study was to evaluate the orthopedic manifestations and potential pitfalls in the surgical treatments of pathological fractures in a series of patients treated in our institution who were affected by pycnodysostosis. Methods: We retrospectively evaluated clinical and radiographic characteristics of five patients with pycnodysostosis treated for pathological fractures at our hospital in the past 5 years. Results: Two male and three female patients were included in this study. Four patients had a family history of pycnodysostosis. All the patients were of short stature, but only two underwent growth hormone treatment. All the patients experienced fractures, mostly in their lower limbs and occurring as a result of low-energy trauma. Most of the patients experienced either consolidation delay or nonunion. Conclusions: The orthopedic management of fractures in patients with pycnodysostosis poses an ongoing challenge for orthopedic surgeons. The fact that the bone is simultaneously sclerotic and brittle makes any orthopedic surgical treatment challenging and at a high risk of nonunion in any case.
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Affiliation(s)
- Maria Beatrice Bocchi
- Department of Orthopaedics, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; (M.B.B.); (F.F.); (S.M.); (O.P.)
- Scuola di Specializzazione in Ortopedia e Traumatologia, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Cristina Giuli
- Department of Orthopaedics, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; (M.B.B.); (F.F.); (S.M.); (O.P.)
- Scuola di Specializzazione in Ortopedia e Traumatologia, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Francesco Farine
- Department of Orthopaedics, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; (M.B.B.); (F.F.); (S.M.); (O.P.)
- Scuola di Specializzazione in Ortopedia e Traumatologia, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Camilla Ravaioli
- Department of Orthopaedics, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; (M.B.B.); (F.F.); (S.M.); (O.P.)
- Scuola di Specializzazione in Ortopedia e Traumatologia, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Sara Martellini
- Department of Orthopaedics, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; (M.B.B.); (F.F.); (S.M.); (O.P.)
- Scuola di Specializzazione in Ortopedia e Traumatologia, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Pasquale Farsetti
- Department of Clinical Science and Translational Medicine, Section of Orthopaedics and Traumatology, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Osvaldo Palmacci
- Department of Orthopaedics, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; (M.B.B.); (F.F.); (S.M.); (O.P.)
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2
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Pečar Fonović U, Kos J, Mitrović A. Compensational role between cathepsins. Biochimie 2024:S0300-9084(24)00085-3. [PMID: 38663456 DOI: 10.1016/j.biochi.2024.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/03/2024] [Accepted: 04/22/2024] [Indexed: 04/30/2024]
Abstract
Cathepsins, a family of lysosomal peptidases, play a crucial role in maintaining cellular homeostasis by regulating protein turnover and degradation as well as many specific regulatory actions that are important for proper cell function and human health. Alterations in the activity and expression of cathepsins have been observed in many diseases such as cancer, inflammation, neurodegenerative disorders, bone remodelling-related conditions and others. These changes are not exclusively harmful, but rather appear to be a compensatory response on the lack of one cathepsin in order to maintain tissue integrity. The upregulation of specific cathepsins in response to the inhibition or dysfunction of other cathepsins suggests a fine-tuned system of proteolytic balance and understanding the compensatory role of cathepsins may improve therapeutic potential of cathepsin's inhibitors. Selectively targeting one cathepsin or modulating their activity could offer new treatment strategies for a number of diseases. This review emphasises the need for comprehensive research into cathepsin biology in the context of disease. The identification of the specific cathepsins involved in compensatory responses, the elucidation of the underlying molecular mechanisms and the development of targeted interventions could lead to innovative therapeutic approaches.
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Affiliation(s)
- Urša Pečar Fonović
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva Cesta 7, 1000, Ljubljana, Slovenia.
| | - Janko Kos
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva Cesta 7, 1000, Ljubljana, Slovenia; Department of Biotechnology, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia.
| | - Ana Mitrović
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva Cesta 7, 1000, Ljubljana, Slovenia; Department of Biotechnology, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia.
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3
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Hald JD, Beck-Nielsen S, Gregersen PA, Gjørup H, Langdahl B. Pycnodysostosis in children and adults. Bone 2023; 169:116674. [PMID: 36646263 DOI: 10.1016/j.bone.2023.116674] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/02/2023] [Accepted: 01/05/2023] [Indexed: 01/14/2023]
Affiliation(s)
- Jannie Dahl Hald
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Denmark; Centre for Rare Diseases, Department of Pediatrics, Aarhus University Hospital, Denmark.
| | - Signe Beck-Nielsen
- Centre for Rare Diseases, Department of Pediatrics, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark
| | - Pernille Axel Gregersen
- Centre for Rare Diseases, Department of Pediatrics, Aarhus University Hospital, Denmark; Department of Clinical Genetics, Aarhus University Hospital, Denmark
| | - Hans Gjørup
- Centre of Oral Health in Rare Diseases, Department of Maxillofacial Surgery, Aarhus University Hospital, Denmark
| | - Bente Langdahl
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark
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4
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Everts V, Jansen IDC, de Vries TJ. Mechanisms of bone resorption. Bone 2022; 163:116499. [PMID: 35872106 DOI: 10.1016/j.bone.2022.116499] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 07/12/2022] [Accepted: 07/15/2022] [Indexed: 01/08/2023]
Affiliation(s)
- Vincent Everts
- Department of Oral Cell Biology, Academic Center for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Amsterdam, the Netherlands; Department of Anatomy, Dental Faculty, Chulalongkorn University, Bangkok, Thailand.
| | - Ineke D C Jansen
- Department of Periodontology, Academic Center for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Amsterdam, the Netherlands
| | - Teun J de Vries
- Department of Periodontology, Academic Center for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Amsterdam, the Netherlands
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5
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Nandipati VS, Chapla A, Jebasingh FK, Charlu AP, Jepegnanam TS, Cherian KE, Paul TV, Thomas N. Cathepsin K mutation-A subtle clinical presentation. J Endocr Soc 2022; 6:bvac102. [PMID: 35854980 PMCID: PMC9281869 DOI: 10.1210/jendso/bvac102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Indexed: 11/19/2022] Open
Abstract
Abstract
Introduction
Pyknodysostosis is an uncommon inherited disorder associated with consanguinity; often presenting with sclerotic bone disease, short stature, dysmorphic features and recurrent fragility fractures at an early age.
Case history
A 34-year-old lady was evaluated for the cause of recurrent fragility fractures. She was born of a third-degree consanguineous marriage and had a twin brother who was short statured. The index patient had a height of 141 cm, dysmorphic features including frontoparietal bossing, blue sclera with short stubby fingers and toes. Radiological evaluation revealed diffuse osteosclerosis with acro-osteolysis exclusively in the toes, apart from mid-facial hypoplasia, lack of pneumatisation of the paranasal sinuses, dental abnormalities and scoliosis. Dual-energy X-ray absorptiometry revealed increased bone mineral density. Based on the clinical features, the patient was tested for Cathepsin K gene variants using Next Generation Sequencing, and was found to be positive for a novel homozygous c.224T>C, p. Met75Thr likely pathogenic missense variant.
Discussion
This patient presented at a later age than expected with recurrent fragility fractures and the diagnosis was not suspected till adulthood, owing to the subtle clinical features. Confirmation with genetic testing helped in establishing the diagnosis.
Conclusion
Pyknodysostosis, although uncommon, is one of the differential diagnoses for diffuse osteosclerosis presenting with recurrent fragility fractures. Next generation sequencing in an appropriate setting may confirm the diagnosis.
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Affiliation(s)
| | - Aaron Chapla
- Department of Endocrinology, Diabetes and Metabolism , Christian Medical College Vellore, India
| | - Felix K Jebasingh
- Department of Endocrinology, Diabetes and Metabolism , Christian Medical College Vellore, India
| | - Arun Paul Charlu
- Department of Dental and Oral Surgery Unit-1 , Christian Medical College Vellore, India
| | | | - Kripa Elizabeth Cherian
- Department of Endocrinology, Diabetes and Metabolism , Christian Medical College Vellore, India
| | - Thomas V Paul
- Department of Endocrinology, Diabetes and Metabolism , Christian Medical College Vellore, India
| | - Nihal Thomas
- Department of Endocrinology, Diabetes and Metabolism , Christian Medical College Vellore, India
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6
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Zhu L, Tang Y, Li XY, Keller ET, Yang J, Cho JS, Feinberg TY, Weiss SJ. Osteoclast-mediated bone resorption is controlled by a compensatory network of secreted and membrane-tethered metalloproteinases. Sci Transl Med 2021; 12:12/529/eaaw6143. [PMID: 32024800 DOI: 10.1126/scitranslmed.aaw6143] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 10/03/2019] [Accepted: 01/02/2020] [Indexed: 12/11/2022]
Abstract
Osteoclasts actively remodel both the mineral and proteinaceous components of bone during normal growth and development as well as pathologic states ranging from osteoporosis to bone metastasis. The cysteine proteinase cathepsin K confers osteoclasts with potent type I collagenolytic activity; however, cathepsin K-null mice, as well as cathepsin K-mutant humans, continue to remodel bone and degrade collagen by as-yet-undefined effectors. Here, we identify a cathepsin K-independent collagenolytic system in osteoclasts that is composed of a functionally redundant network of the secreted matrix metalloproteinase MMP9 and the membrane-anchored matrix metalloproteinase MMP14. Unexpectedly, whereas deleting either of the proteinases individually leaves bone resorption intact, dual targeting of Mmp9 and Mmp14 inhibited the resorptive activity of mouse osteoclasts in vitro and in vivo and human osteoclasts in vitro. In vivo, Mmp9/Mmp14 conditional double-knockout mice exhibited marked increases in bone density and displayed a highly protected status against either parathyroid hormone- or ovariectomy-induced pathologic bone loss. Together, these studies characterize a collagenolytic system operative in mouse and human osteoclasts and identify the MMP9/MMP14 axis as a potential target for therapeutic interventions for bone-wasting disease states.
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Affiliation(s)
- Lingxin Zhu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan 430079, China. .,Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.,Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yi Tang
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.,Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Xiao-Yan Li
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.,Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Evan T Keller
- Department of Pathology, Department of Urology and the Institute of Gerontology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jingwen Yang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan 430079, China.,School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jung-Sun Cho
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.,Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Tamar Y Feinberg
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.,Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Stephen J Weiss
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA. .,Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
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7
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Choudhury D, Biswas S. Structure-guided protein engineering of human cathepsin L for efficient collagenolytic activity. Protein Eng Des Sel 2021; 34:6213762. [PMID: 33825882 DOI: 10.1093/protein/gzab005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 01/21/2021] [Accepted: 02/15/2021] [Indexed: 11/14/2022] Open
Abstract
Engineering precise substrate specificity of proteases advances the potential to use them in biotechnological and therapeutic applications. Collagen degradation, a physiological process mediated by collagenases, is an integral part of extracellular matrix remodeling and when uncontrolled, implicated in different pathological conditions. Lysosomal cathepsin-K cleaves triple helical collagen fiber, whereas cathepsin-L cannot do so. In this study, we have imparted collagenolytic property to cathepsin-L, by systematically engineering proline-specificity and glycosaminoglycans (GAG)-binding surface in the protease. The proline-specific mutant shows high specificity for prolyl-peptidic substrate but is incapable of cleaving collagen. Engineering a GAG-binding surface on the proline-specific mutant enabled it to degrade type-I collagen in the presence of chondroitin-4-sulfate (C4-S). We also present the crystal structures of proline-specific (1.4 Å) and collagen-specific (1.8 Å) mutants. Finally docking studies with prolyl-peptidic substrate (Ala-Gly-Pro-Arg-Ala) at the active site and a C4-S molecule at the GAG-binding site enable us to identify key structural features responsible for collagenolytic activity of cysteine cathepsins.
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Affiliation(s)
- Debi Choudhury
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, India
| | - Sampa Biswas
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, India.,Homi Bhaba National Institute, Anushaktinagar, Mumbai 400 094, India
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8
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Jansen ID, Papapoulos SE, Bravenboer N, de Vries TJ, Appelman-Dijkstra NM. Increased Bone Resorption during Lactation in Pycnodysostosis. Int J Mol Sci 2021; 22:ijms22041810. [PMID: 33670411 PMCID: PMC7918824 DOI: 10.3390/ijms22041810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/04/2021] [Accepted: 02/07/2021] [Indexed: 12/03/2022] Open
Abstract
Pycnodysostosis, a rare autosomal recessive skeletal dysplasia, is caused by a deficiency of cathepsin K. Patients have impaired bone resorption in the presence of normal or increased numbers of multinucleated, but dysfunctional, osteoclasts. Cathepsin K degrades collagen type I and generates N-telopeptide (NTX) and the C-telopeptide (CTX) that can be quantified. Levels of these telopeptides are increased in lactating women and are associated with increased bone resorption. Nothing is known about the consequences of cathepsin K deficiency in lactating women. Here we present for the first time normalized blood and CTX measurements in a patient with pycnodysostosis, exclusively related to the lactation period. In vitro studies using osteoclasts derived from blood monocytes during lactation and after weaning further show consistent bone resorption before and after lactation. Increased expression of cathepsins L and S in osteoclasts derived from the lactating patient suggests that other proteinases could compensate for the lack of cathepsin K during the lactation period of pycnodysostosis patients.
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Affiliation(s)
- Ineke D.C. Jansen
- Department of Periodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands; (I.D.C.J.); (T.J.d.V.)
| | - Socrates E. Papapoulos
- Center for Bone Quality Department of Internal Medicine division of Endocrinology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands;
| | - Nathalie Bravenboer
- Department of Clinical Chemistry, Amsterdam University Medical Center, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands;
| | - Teun J. de Vries
- Department of Periodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands; (I.D.C.J.); (T.J.d.V.)
| | - Natasha M. Appelman-Dijkstra
- Center for Bone Quality Department of Internal Medicine division of Endocrinology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands;
- Correspondence:
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Doherty MA, Langdahl BL, Vogel I, Haagerup A. Clinical and genetic evaluation of Danish patients with pycnodysostosis. Eur J Med Genet 2021; 64:104135. [PMID: 33429075 DOI: 10.1016/j.ejmg.2021.104135] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 09/02/2020] [Accepted: 01/03/2021] [Indexed: 01/01/2023]
Abstract
BACKGROUND Pycnodysostosis is a rare autosomal recessive osteosclerotic skeletal dysplasia caused by variants in the cathepsin K gene (CTSK). Clinical features include short stature, bone fragility, characteristic facial features and acro-osteolysis of the distal phalanges. Usually, patients suffer from multiple bone fractures. The purpose of this study was to describe the Danish population of pycnodysostosis patients with respect to genotype, phenotype and the prevalence of complications. We collected medical history, performed clinical examination, collected blood- and urine samples, performed dual-energy x-ray absorptiometry scan (DXA) and high-resolution peripheral quantitative computed tomography scan (HRpQCT) and obtained clinical photos. Information about complications, bone mineral density and bone markers in the blood were collected and analysed. RESULTS Ten patients with a median age of 32 years ranging from five to 51 years participated. The pycnodysostosis phenotype varied with respect to the number of bone fractures and degree of complications. DXA and HRpQCT showed high bone mineral density. A tendency of growth hormone treatment escalating growth and increasing final height was seen. A marker of bone resorption measured in blood was within normal range in nine patients and elevated in one patient. A novel pathogenic variant in CSTK causing pycnodysostosis was detected in two related patients. Moreover information about the patients' own health perception was reported. An example being they rated their mental health to be good despite multiple bone fractures. CONCLUSION This study provides information about genotypes and phenotypes in a Danish pycnodysostosis population. It reports new data about the complications such as bone fractures and it elucidates the levels of bone turnover markers as well as the density of the bones in one of the biggest cohort of pycnodysostosis patients ever published. An individualised approach to treatment in this patient group is necessary as the phenotype including complications varies between patients. Additional studies are needed to further understand genotype-phenotype correlations.
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Affiliation(s)
| | - Bente L Langdahl
- Department of Endocrinology, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark; Department of Biomedicine, Aarhus University, Denmark.
| | - Ida Vogel
- Department of Clinical Genetics, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark; Department of Biomedicine, Aarhus University, Denmark.
| | - Annette Haagerup
- NIDO∣danmark, Gødstrup, Denmark; Department of Clinical Medicine, Aarhus University, Denmark.
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10
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Yu J, Adapala NS, Doherty L, Sanjay A. Cbl-PI3K interaction regulates Cathepsin K secretion in osteoclasts. Bone 2019; 127:376-385. [PMID: 31299383 PMCID: PMC6708784 DOI: 10.1016/j.bone.2019.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 07/06/2019] [Accepted: 07/08/2019] [Indexed: 10/26/2022]
Abstract
Effective bone resorption by osteoclasts is critical for balanced bone remodeling. We have previously reported that mice harboring a substitution mutation of tyrosine 737 to phenylalanine in the adapter protein Cbl (CblY737F, YF) have increased bone volume partly due to decreased osteoclast-mediated bone resorption. The CblY737F mutation abrogates interaction between Cbl and the p85 subunit of PI3K. Here, we studied the mechanism for defective resorptive function of YF mutant osteoclasts. The YF osteoclasts had intact actin cytoskeletons and sealing zones. Expression and localization of proteins needed for acidification of the resorptive lacunae were also comparable between the WT and YF osteoclasts. In contrast, secretion of Cathepsin K, a major protease needed to degrade collagen, was diminished in the conditioned media derived from YF osteoclasts. The targeting of Cathepsin K into LAMP2-positive vesicles was also compromised due to decreased number of LAMP2-positive vesicles in YF osteoclasts. Further, we found that in contrast to WT, conditioned media derived from YF osteoclasts promoted increased numbers of alkaline phosphatase positive colonies, and increased expression of osteogenic markers in WT calvarial cultures. Cumulatively, our results suggest that the Cbl-PI3K interaction regulates Cathepsin K secretion required for proper bone resorption, and secretion of factors which promote osteogenesis.
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Affiliation(s)
- Jungeun Yu
- Department of Orthopaedic Surgery, UConn Health, Farmington, CT 06030, United States of America
| | - Naga Suresh Adapala
- Department of Orthopaedic Surgery, UConn Health, Farmington, CT 06030, United States of America
| | - Laura Doherty
- Department of Orthopaedic Surgery, UConn Health, Farmington, CT 06030, United States of America
| | - Archana Sanjay
- Department of Orthopaedic Surgery, UConn Health, Farmington, CT 06030, United States of America.
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11
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Abstract
The group of sclerosing bone dysplasia's is a clinically and genetically heterogeneous group of rare bone disorders which, according to the latest Nosology and classification of genetic skeletal disorders (2015), can be subdivided in three subgroups; the neonatal osteosclerotic dysplasias, the osteopetroses and related disorders and the other sclerosing bone disorders. Here, we give an overview of the most important radiographic and clinical symptoms, the underlying genetic defect and potential treatment options of the different sclerosing dysplasias included in these subgroups.
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Affiliation(s)
- Eveline Boudin
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.
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12
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Abstract
PURPOSE OF REVIEW The group of sclerosing bone disorders encompasses a variety of disorders all marked by increased bone mass. In this review, we give an overview of the genetic causes of this heterogeneous group of disorders and briefly touch upon the value of these findings for the development of novel therapeutic agents. RECENT FINDINGS Advances in the next-generation sequencing technologies are accelerating the molecular dissection of the pathogenic mechanisms underlying skeletal dysplasias. Throughout the years, the genetic cause of these disorders has been extensively studied which resulted in the identification of a variety of disease-causing genes and pathways that are involved in bone formation by osteoblasts, bone resorption by osteoclasts, or both processes. Due to this rapidly increasing knowledge, the insights into the regulatory mechanisms of bone metabolism are continuously improving resulting in the identification of novel therapeutic targets for disorders with reduced bone mass and increased bone fragility.
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Affiliation(s)
- Raphaël De Ridder
- Centre of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium
| | - Eveline Boudin
- Centre of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium
| | - Geert Mortier
- Centre of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium
| | - Wim Van Hul
- Centre of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium.
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13
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Amar S, Smith L, Fields GB. Matrix metalloproteinase collagenolysis in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2017; 1864:1940-1951. [PMID: 28456643 PMCID: PMC5605394 DOI: 10.1016/j.bbamcr.2017.04.015] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 04/20/2017] [Accepted: 04/24/2017] [Indexed: 01/08/2023]
Abstract
The proteolytic processing of collagen (collagenolysis) is critical in development and homeostasis, but also contributes to numerous pathologies. Mammalian interstitial collagenolytic enzymes include members of the matrix metalloproteinase (MMP) family and cathepsin K. While MMPs have long been recognized for their ability to catalyze the hydrolysis of collagen, the roles of individual MMPs in physiological and pathological collagenolysis are less defined. The use of knockout and mutant animal models, which reflect human diseases, has revealed distinct collagenolytic roles for MT1-MMP and MMP-13. A better understanding of temporal and spatial collagen processing, along with the knowledge of the specific MMP involved, will ultimately lead to more effective treatments for cancer, arthritis, cardiovascular conditions, and infectious diseases. This article is part of a Special Issue entitled: Matrix Metalloproteinases edited by Rafael Fridman.
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Affiliation(s)
- Sabrina Amar
- Department of Chemistry & Biochemistry, Florida Atlantic University, Jupiter, FL 33458, USA.
| | - Lyndsay Smith
- Department of Chemistry & Biochemistry, Florida Atlantic University, Jupiter, FL 33458, USA.
| | - Gregg B Fields
- Department of Chemistry & Biochemistry, Florida Atlantic University, Jupiter, FL 33458, USA; Department of Chemistry, The Scripps Research Institute/Scripps Florida, Jupiter, FL 33458, USA.
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Barley Seedling Extracts Inhibit RANKL-Induced Differentiation, Fusion, and Maturation of Osteoclasts in the Early-to-Late Stages of Osteoclastogenesis. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:6072573. [PMID: 28567098 PMCID: PMC5439073 DOI: 10.1155/2017/6072573] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 04/03/2017] [Accepted: 04/18/2017] [Indexed: 01/05/2023]
Abstract
The number of patients with osteoporosis is increasing worldwide, and a decrease in bone mass is a main risk factor for fracture. The prevention of bone loss is critical for improving the quality of life for patients. However, the long-term use of antiosteoporotic agents is limited due to their side effects. Barley has been traditionally ingested for thousands of years as a safe, natural food with pharmaceutical properties, and its seedling can enhance the biological activity of the medicinal components found in food. This study aimed to clarify the antiresorptive activity of barley seedling and its mode of action. Barley seedling extracts (BSE) dose-dependently inhibited RANKL-induced osteoclast differentiation with alteration of IκB degradation, c-Fos, and NFATc1 molecules in the early-to-middle stages of osteoclastogenesis. In the late phase of osteoclastogenesis, BSE also prevented DC-STAMP and cathepsin K, which are required for cell fusion and bone degradation, such as osteoclast function. In conclusion, barley seedling from natural foods may provide long-term safety and be useful for the prevention or treatment of osteoclast-mediated bone metabolic diseases, including osteoporosis.
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Ketterer S, Gomez-Auli A, Hillebrand LE, Petrera A, Ketscher A, Reinheckel T. Inherited diseases caused by mutations in cathepsin protease genes. FEBS J 2017; 284:1437-1454. [PMID: 27926992 DOI: 10.1111/febs.13980] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/11/2016] [Accepted: 11/29/2016] [Indexed: 02/07/2023]
Abstract
Lysosomal cathepsins are proteolytic enzymes increasingly recognized as prognostic markers and potential therapeutic targets in a variety of diseases. In those conditions, the cathepsins are mostly overexpressed, thereby driving the respective pathogenic processes. Although less known, there are also diseases with a genetic deficiency of cathepsins. In fact, nowadays 6 of the 15 human proteases called 'cathepsins' have been linked to inherited syndromes. However, only three of these syndromes are typical lysosomal storage diseases, while the others are apparently caused by defective cleavage of specific protein substrates. Here, we will provide an introduction on lysosomal cathepsins, followed by a brief description of the clinical symptoms of the various genetic diseases. For each disease, we focus on the known mutations of which many have been only recently identified by modern genome sequencing approaches. We further discuss the effect of the respective mutation on protease structure and activity, the resulting pathogenesis, and possible therapeutic strategies.
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Affiliation(s)
- Stephanie Ketterer
- Medical Faculty, Institute of Molecular Medicine and Cell Research, Albert-Ludwigs-University Freiburg, Germany.,Faculty of Biology, Albert-Ludwigs-University Freiburg, Germany
| | - Alejandro Gomez-Auli
- Medical Faculty, Institute of Molecular Medicine and Cell Research, Albert-Ludwigs-University Freiburg, Germany.,Faculty of Biology, Albert-Ludwigs-University Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-University Freiburg, Germany
| | - Larissa E Hillebrand
- Medical Faculty, Institute of Molecular Medicine and Cell Research, Albert-Ludwigs-University Freiburg, Germany.,Faculty of Biology, Albert-Ludwigs-University Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, Freiburg, Germany
| | - Agnese Petrera
- Medical Faculty, Institute of Molecular Medicine and Cell Research, Albert-Ludwigs-University Freiburg, Germany
| | - Anett Ketscher
- Medical Faculty, Institute of Molecular Medicine and Cell Research, Albert-Ludwigs-University Freiburg, Germany
| | - Thomas Reinheckel
- Medical Faculty, Institute of Molecular Medicine and Cell Research, Albert-Ludwigs-University Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, Freiburg, Germany
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Manyonda IT, Choy MY. Collagen Phagocytosis by Human Extravillous Trophoblast: Potential Role in Trophoblastic Invasion. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/107155769900600308] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Isaac T. Manyonda
- Division of Immunology, Department of Cellular and Molecular Sciences, St. George's Hospital Medical School, Cranmer Terrace, London SW17 ORE Kingdom
| | - Mei Y. Choy
- Division of Immunology, Department of Cellular and Molecular Sciences and Department of Obstetrics and Gynaecology, St. George's Hospital Medical School, London, United Kingdom
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Brömme D, Panwar P, Turan S. Cathepsin K osteoporosis trials, pycnodysostosis and mouse deficiency models: Commonalities and differences. Expert Opin Drug Discov 2016; 11:457-72. [DOI: 10.1517/17460441.2016.1160884] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Dieter Brömme
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, Canada
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of British Columbia, Vancouver, Canada
- Centre for Blood Research, University of British Columbia, Vancouver, Canada
| | - Preety Panwar
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, Canada
- Centre for Blood Research, University of British Columbia, Vancouver, Canada
| | - Serap Turan
- Department of Pediatric Endocrinology, Marmara University, Istanbul, Turkey
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18
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Verbovšek U, Van Noorden CJ, Lah TT. Complexity of cancer protease biology: Cathepsin K expression and function in cancer progression. Semin Cancer Biol 2015; 35:71-84. [DOI: 10.1016/j.semcancer.2015.08.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/19/2015] [Accepted: 08/21/2015] [Indexed: 12/18/2022]
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Total Hip Arthroplasty after Treatment of an Atypical Subtrochanteric Femoral Fracture in a Patient with Pycnodysostosis. Case Rep Orthop 2015; 2015:731910. [PMID: 26448892 PMCID: PMC4581509 DOI: 10.1155/2015/731910] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 08/31/2015] [Indexed: 11/17/2022] Open
Abstract
The authors describe the case of a 51-year-old woman with an osteonecrosis of her right femoral head after treatment of an atypical subtrochanteric fracture caused by pycnodysostosis. She had this fracture after a low-trauma fall. She was of short stature with typical facial features, short stubby hands, and radiological features including open cranial sutures, obtuse mandible, and generalized skeletal sclerosis. The majority of cases of atypical subtrochanteric fractures are associated with long-term use of bisphosphonates; some occur in bisphosphonate-free patients. We report a rare case of total hip arthroplasty (THA) in a patient with pycnodysostosis who developed an osteonecrosis of the femoral head after treatment of an atypical subtrochanteric femoral fracture. We performed cementless THA in combination with a plate and cables. Cementless THA is a potential intervention in a patient with pycnodysostosis; although the bone quality may have been sclerotic, healing is not a problem in this condition.
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Chapurlat RD. Odanacatib: a review of its potential in the management of osteoporosis in postmenopausal women. Ther Adv Musculoskelet Dis 2015; 7:103-9. [PMID: 26029271 PMCID: PMC4426100 DOI: 10.1177/1759720x15580903] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Odanacatib is a cathepsin K inhibitor developed for the treatment of postmenopausal osteoporosis. It is a bone resorption inhibitor, but which preserves bone formation to some extent. It can be administered once a week, in tablets also containing vitamin D. In a large clinical development program, it has been shown that odanacatib reduces bone resorption, with a reduction of about 60-70% in biochemical markers of resorption, while bone formation decreases to a lesser magnitude. Odanacatib continuously increases bone mineral density (BMD) at the hip and lumbar spine over 5 years. Once it is stopped, a complete resolution of effect is observed, with declining BMD and increased bone turnover. Bone microarchitecture and bone strength have also been improved in clinical trials using quantitative computed tomography (QCT) at the lumbar spine and hip, and high resolution peripheral QCT at the distal radius and tibia. In a phase III trial involving 16,713 postmenopausal women ⩾65 years of age with low BMD, the risk of fragility fracture was significantly reduced at the spine, hip and other nonvertebral sites compared with the placebo group. Odanacatib has been generally well tolerated, with no observation of osteonecrosis of the jaw so far, but with exceptional observations of subtrochanteric atypical fracture and morphea-like lesions. Odanacatib appears a useful new option in the treatment of postmenopausal osteoporosis.
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Affiliation(s)
- Roland D Chapurlat
- INSERM UMR 1033, Université de Lyon, Hôpital E Herriot, 69437 Lyon cedex 03, France
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22
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Chapurlat RD. RETRACTED: Odanacatib for the treatment of postmenopausal osteoporosis. Expert Opin Pharmacother 2013; 15:97-102. [DOI: 10.1517/14656566.2014.853038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Leung P, Pickarski M, Zhuo Y, Masarachia PJ, Duong LT. The effects of the cathepsin K inhibitor odanacatib on osteoclastic bone resorption and vesicular trafficking. Bone 2011; 49:623-35. [PMID: 21718816 DOI: 10.1016/j.bone.2011.06.014] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 06/10/2011] [Accepted: 06/14/2011] [Indexed: 11/28/2022]
Abstract
Odanacatib (ODN) is a selective, potent and reversible inhibitor of cathepsin K (CatK) that inhibits bone loss in postmenopausal osteoporosis. Evidence from osteoclast (OC) formation from bone marrow of CatK(-/-) mice or human OC progenitors treated with ODN, demonstrated that CatK inhibition has no effect on osteoclastogenesis or survival of OCs. Although having no impact on OC activation, ODN reduces resorption activity as measured by CTx release (IC(50)=9.4 nM) or resorption area (IC(50)=6.5 nM). While untreated cells generate deep trail-like resorption lacunae, treated OCs form small discrete shallow pits. ODN leads to significant accumulation of intracellular vesicles intensely stained for CatK and TRAP. CatK (+) vesicles localize toward the basolateral and functional secretory membranes of the polarized OC and TRAP(+) vesicles evenly distribute in the cytoplasm, suggesting that ODN disrupts multiple vesicular trafficking pathways. Intracellular levels of both precursor and mature TRAP were increased by 2-fold and the pre-pro and mature CatK by 6- and 2-fold in ODN-treated OCs compared to untreated controls. ODN treated OC accumulates labeled degraded bone matrix proteins in CatK containing vesicles. In summary, ODN treatment inhibits bone resorption by blocking degradation of demineralized collagen in the resorption lacunae, and retarding transcytosis for further processing of degraded proteins.
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Affiliation(s)
- P Leung
- Merck Sharp, & Dohme Corp., P.O. Box 100, Whitehouse Station, NJ 08889, USA
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25
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Costa AG, Cusano NE, Silva BC, Cremers S, Bilezikian JP. Cathepsin K: its skeletal actions and role as a therapeutic target in osteoporosis. Nat Rev Rheumatol 2011; 7:447-56. [PMID: 21670768 DOI: 10.1038/nrrheum.2011.77] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Bone remodeling consists of two phases--bone resorption and bone formation--that are normally balanced. When bone resorption exceeds bone formation, pathologic processes, such as osteoporosis, can result. Cathepsin K is a member of the papain family of cysteine proteases that is highly expressed by activated osteoclasts. Cathepsin K readily degrades type I collagen, the major component of the organic bone matrix. With such a major role in the initial process of bone resorption, cathepsin K has become a therapeutic target in osteoporosis. The antiresorptive properties of cathepsin K inhibitors have been studied in phase I and phase II clinical trials. Phase III studies are currently underway for odanacatib, a selective cathepsin K inhibitor.
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Affiliation(s)
- Aline G Costa
- Metabolic Bone Diseases Unit, Division of Endocrinology, Department of Medicine, College of Physicians and Surgeons, Columbia University, 630 W. 168th Street, New York, NY 10032, USA
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Yates CJ, Bartlett MJ, Ebeling PR. An atypical subtrochanteric femoral fracture from pycnodysostosis: a lesson from nature. J Bone Miner Res 2011; 26:1377-9. [PMID: 21611976 DOI: 10.1002/jbmr.308] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This case describes a man with an unusual cause of an atypical subtrochanteric fracture, pycnodysostosis. This condition results from mutations involving the cathepsin K gene. New antiresorptive treatments for osteoporosis inhibit the cathepsin K enzyme in osteoclasts. Therefore, there should be vigilant monitoring for the development of long-term complications noted to occur in diseases of reduced osteoclast function, including pycnodysostosis, in patients receiving these novel antiresorptive agents.
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Affiliation(s)
- Christopher J Yates
- Endocrinology Unit, University of Melbourne, Western Hospital, Footscray, Victoria, Australia
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Henriksen K, Bollerslev J, Everts V, Karsdal MA. Osteoclast activity and subtypes as a function of physiology and pathology--implications for future treatments of osteoporosis. Endocr Rev 2011; 32:31-63. [PMID: 20851921 DOI: 10.1210/er.2010-0006] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Osteoclasts have traditionally been associated exclusively with catabolic functions that are a prerequisite for bone resorption. However, emerging data suggest that osteoclasts also carry out functions that are important for optimal bone formation and bone quality. Moreover, recent findings indicate that osteoclasts have different subtypes depending on their location, genotype, and possibly in response to drug intervention. The aim of the current review is to describe the subtypes of osteoclasts in four different settings: 1) physiological, in relation to turnover of different bone types; 2) pathological, as exemplified by monogenomic disorders; 3) pathological, as identified by different disorders; and 4) in drug-induced situations. The profiles of these subtypes strongly suggest that these osteoclasts belong to a heterogeneous cell population, namely, a diverse macrophage-associated cell type with bone catabolic and anabolic functions that are dependent on both local and systemic parameters. Further insight into these osteoclast subtypes may be important for understanding cell-cell communication in the bone microenvironment, treatment effects, and ultimately bone quality.
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Affiliation(s)
- K Henriksen
- Nordic Bioscience A/S, Herlev Hovedgade 207, DK-2730 Herlev, Denmark.
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29
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Rothenbühler A, Piquard C, Gueorguieva I, Lahlou N, Linglart A, Bougnères P. Near normalization of adult height and body proportions by growth hormone in pycnodysostosis. J Clin Endocrinol Metab 2010; 95:2827-31. [PMID: 20357177 DOI: 10.1210/jc.2009-2531] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT Mutations in the cathepsin K gene (CTSK) cause a very rare form of short-limb dwarfism called pyknodysostosis (online inheritance in man 265800) that reduces adult height to 130-150 cm. OBJECTIVE To study the effects of GH in children with pyknodysostosis. DESIGN AND METHODS This was a pilot open study of three children with pyknodysostosis (P1, P2, P3) and 16 age-matched children with idiopathic short stature (ISS) treated with a similar IGF-I-based dosing of GH therapy. P1, P2, and P3 received a mean GH dose of 29, 67, and 120 microg/kg x d, respectively, during 12, 6.5, and 5 yr, whereas the ISS group received a mean dose of 62 +/- 21 microg/kg x d during 5.4 +/- 2 yr. RESULTS P1, P2, and P3 had the typical clinical and radiological features of pyknodysostosis. They were shown to carry three different homozygous missense mutations of the CTSK gene. After onset of GH at 4.5, 5.4, and 10.9 yr of age, respectively, height increased from -2, -4.2, and -3 SD score to -1, -0.5, and -1 SD score after a 12, 6.5, and 5 yr GH treatment. Remarkably, body disproportion was largely corrected by GH treatment. IGF-I levels in P1, P2, and P3 were within the range of the ISS group. CONCLUSIONS Pyknodysostotic patients can reach near-normal stature and skeletal proportions with a personalized GH treatment targeted at appropriate IGF-I levels. Given the severity of this rare dwarfism, we propose that GH should be offered to affected children.
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Affiliation(s)
- Anya Rothenbühler
- Department of Pediatric Endocrinology, Hôpital Saint Vincent de Paul, Assistance Publique-Hôpitaux de Paris, Faculté de Médecine Paris Descartes, 75014 Paris, France
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30
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Wilson S, Brömme D. Potential role of cathepsin K in the pathophysiology of mucopolysaccharidoses. J Pediatr Rehabil Med 2010; 3:139-46. [PMID: 21629671 PMCID: PMC3103771 DOI: 10.3233/prm-2010-0116] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cathepsin K, a papain-like cysteine protease, is highly expressed in osteoclasts and plays a critical role in bone resorption. Dysfunction of the enzyme leads to various skeletal abnormalities. The recent knowledge that the collagenolytic activity of cathepsin K depends on interactions with bone and cartilage-resident glycosaminoglycans (GAGs) may shed some light on diseases such as mucopolysaccharidoses (MPSs). MPSs are a group of lysosomal storage diseases characterized by the accumulation of GAGs in tissues including bone. Typical pathological features of these diseases include skeletal abnormalities such as dysostosis multiplex, short stature, and multiple irregularities in bone development. We describe how further investigation of the cathepsin K/GAG complexes could provide valuable insights into the bone pathology associated with MPS diseases. In this review, we discuss the inhibition of osteoclast function through altered activity of cathepsin K by GAGs and offer insight into a mechanism for the bone pathology seen in MPS patients.
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Affiliation(s)
- Susan Wilson
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, Canada
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31
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Everts V, de Vries TJ, Helfrich MH. Osteoclast heterogeneity:. Biochim Biophys Acta Mol Basis Dis 2009; 1792:757-65. [DOI: 10.1016/j.bbadis.2009.05.004] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 05/15/2009] [Accepted: 05/18/2009] [Indexed: 01/11/2023]
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Pennypacker B, Shea M, Liu Q, Masarachia P, Saftig P, Rodan S, Rodan G, Kimmel D. Bone density, strength, and formation in adult cathepsin K (-/-) mice. Bone 2009; 44:199-207. [PMID: 18845279 DOI: 10.1016/j.bone.2008.08.130] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 08/27/2008] [Accepted: 08/29/2008] [Indexed: 11/23/2022]
Abstract
Cathepsin K (CatK) is a cysteine protease expressed predominantly in osteoclasts, that plays a prominent role in degrading Type I collagen. Growing CatK null mice have osteopetrosis associated with a reduced ability to degrade bone matrix. Bone strength and histomorphometric endpoints in young adult CatK null mice aged more than 10 weeks have not been studied. The purpose of this paper is to describe bone mass, strength, resorption, and formation in young adult CatK null mice. In male and female wild-type (WT), heterozygous, and homozygous CatK null mice (total N=50) aged 19 weeks, in-life double fluorochrome labeling was performed. Right femurs and lumbar vertebral bodies 1-3 (LV) were evaluated by dual-energy X-ray absorptiometry (DXA) for bone mineral content (BMC) and bone mineral density (BMD). The trabecular region of the femur and the cortical region of the tibia were evaluated by histomorphometry. The left femur and sixth lumbar vertebral body were tested biomechanically. CatK (-/-) mice show higher BMD at the central and distal femur. Central femur ultimate load was positively influenced by genotype, and was positively correlated with both cortical area and BMC. Lumbar vertebral body ultimate load was also positively correlated to BMC. Genotype did not influence the relationship of ultimate load to BMC in either the central femur or vertebral body. CatK (-/-) mice had less lamellar cortical bone than WT mice. Higher bone volume, trabecular thickness, and trabecular number were observed at the distal femur in CatK (-/-) mice. Smaller marrow cavities were also present at the central femur of CatK (-/-) mice. CatK (-/-) mice exhibited greater trabecular mineralizing surface, associated with normal volume-based formation of trabecular bone. Adult CatK (-/-) mice have higher bone mass in both cortical and cancellous regions than WT mice. Though no direct measures of bone resorption rate were made, the higher cortical bone quantity is associated with a smaller marrow cavity and increased retention of non-lamellar bone, signs of decreased endocortical resorption. The relationship of bone strength to BMC does not differ with genotype, indicating the presence of bone tissue of normal quality in the absence of CatK.
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Affiliation(s)
- B Pennypacker
- Department of Molecular Endocrinology and Bone Biology, Merck Research Laboratories, WP26A-1000 West Point, PA 19486, USA.
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Advances in osteoclast biology resulting from the study of osteopetrotic mutations. Hum Genet 2008; 124:561-77. [DOI: 10.1007/s00439-008-0583-8] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Accepted: 10/28/2008] [Indexed: 02/05/2023]
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Mechanisms of the anabolic effects of teriparatide on bone: insight from the treatment of a patient with pycnodysostosis. J Bone Miner Res 2008; 23:1076-83. [PMID: 18302508 DOI: 10.1359/jbmr.080231] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pycnodysostosis is an extremely rare genetic osteosclerosis caused by cathepsin K deficiency. We hypothesized that teriparatide, a potent anabolic agent used in the treatment of osteoporosis, might reduce skeletal fragility by activating bone turnover. We studied a typical case of pycnodysostosis in a 37-yr-old woman who exhibited short stature, skull and thorax deformities, and a history of severe fragility fractures. Cathepsin K gene sequencing was performed. Before and after 6 mo of 20 microg/d teriparatide, biochemical markers of bone turnover were measured, and 3D bone structure and microarchitecture was assessed in vivo by HR-pQCT. Qualitative and quantitative analysis of transiliac bone biopsies were performed, and the degree of mineralization was evaluated by quantitative microradiography. In vitro assessment of bone resorption was performed after separation and differentiation of CD14(+) monocytes from peripheral blood. Bone structure assessed by HR-pQCT on the radius and tibia showed augmentation of cortical and trabecular density. Transiliac bone biopsy showed highly increased bone mass (+63% versus age- and sex-matched controls), a decrease in bone remodeling without evidence of active osteoblasts, and a severe decrease in the dynamic parameters of bone formation (mineralizing surfaces, -90% and bone formation rate, -93% versus age- and sex-matched controls). This depressed bone turnover probably explained the increased degree of mineralization. The presence of a novel missense mutation leading to an A141V amino acid substitution confirmed a genetic defect of cathepsin K as the cause of the disease. The deficiency of active osteoclasts was confirmed by an in vitro study that showed a decreased concentration of CD14(+) monocytes (the precursor of osteoclasts) in blood. These osteoclasts had low resorptive activity when incubated on bone slices. After 6 mo of teriparatide, the structure, microarchitecture, and turnover of bone--assessed by HR-pQCT, histology, and bone turnover markers--remained unchanged. Our data strongly suggest that some features of the osteoclastic phenotype--that are absent in pycnodysostosis--are a prerequisite for the anabolic effect of PTH on osteoblasts.
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Abstract
The name "cysteine protease" refers to the protease's nucleophilic cysteine residue that forms a covalent bond with the carbonyl group of the scissile peptide bond in substrates. The papain-like cysteine proteases, classified as the "C1 family" are the most predominant cysteine proteases. These proteases are found in viruses, plants, primitive parasites, invertebrates, and vertebrates alike. Mammalian papain-like cysteine proteases are also known as cathepsins. This unit discusses cathepsins, and their subcellular and tissue localization, catalytic mechanism, and substrate specificity. Several tables illustrate the properties of the various cathepsins.
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Affiliation(s)
- D Brömme
- Mount Sinai School of Medicine, New York, New York, USA
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36
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Fonteles CSR, Chaves CM, Da Silveira A, Soares ECS, Couto JLP, de Azevedo MDFV. Cephalometric characteristics and dentofacial abnormalities of pycnodysostosis: report of four cases from Brazil. ACTA ACUST UNITED AC 2007; 104:e83-90. [PMID: 17703963 DOI: 10.1016/j.tripleo.2007.05.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 04/09/2007] [Accepted: 05/07/2007] [Indexed: 10/22/2022]
Abstract
Pycnodysostosis (PKND) is a human autosomal recessive genetic disorder characterized mainly by osteosclerosis of the skeleton, severe bone fragility, and short stature. This syndrome usually presents very typical craniofacial deformities, such as beaked nose, micrognathia, hypoplastic midface, open mouth posture, grooved palate, anterior cross-bite, dental crowding, and over-retained deciduous teeth. Early diagnosis and intervention are of the utmost importance. Four cases from the northeast of Brazil are reported including 2 siblings. Features included maxillary retrusion, reduced facial height, open bite, and bone fracture history. Very poor oral hygiene, severe dental caries, and periodontal disease were also present.
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Chavassieux P, Seeman E, Delmas PD. Insights into material and structural basis of bone fragility from diseases associated with fractures: how determinants of the biomechanical properties of bone are compromised by disease. Endocr Rev 2007; 28:151-64. [PMID: 17200084 DOI: 10.1210/er.2006-0029] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Minimal trauma fractures in bone diseases are the result of bone fragility. Rather than considering bone fragility as being the result of a reduced amount of bone, we recognize that bone fragility is the result of changes in the material and structural properties of bone. A better understanding of the contribution of each component of the material composition and structure and how these interact to maintain whole bone strength is obtained by the study of metabolic bone diseases. Disorders of collagen (osteogenesis imperfecta and Paget's disease of bone), mineral content, composition and distribution (fluorosis and osteomalacia); diseases of high remodeling (postmenopausal osteoporosis, hyperparathyroidism, and hyperthyroidism) and low remodeling (osteopetrosis, pycnodysostosis); and other diseases (idiopathic male osteoporosis, corticosteroid-induced osteoporosis) produce abnormalities in the material composition and structure that lead to bone fragility. Observations in patients and in animal models provide insights on the biomechanical consequences of these illnesses and the nature of the qualities of bone that determine its strength.
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Affiliation(s)
- P Chavassieux
- Institut National de la Santé et de la Recherche Médicale Unit 831, Pavillon F, Hopital E. Herriot, 69437 Lyon Cedex 08, France
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Alroy J, Ucci AA. Skin biopsy: a useful tool in the diagnosis of lysosomal storage diseases. Ultrastruct Pathol 2007; 30:489-503. [PMID: 17182441 DOI: 10.1080/01913120500520986] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In this report, the authors summarize their 19-year experience with over 200 biochemically proven cases of lysosomal storage diseases using electron microscopic screening of more than 950 skin biopsies. They found that electron microscopy (EM) is a highly sensitive, efficient, cost-effective, and rapid diagnostic screening tool for evaluation of lysosomal storage diseases in skin biopsies. Although EM is more expensive than a single enzyme assay, it can exclude more than 90% of cases in which lysosomal storage disease is being considered. EM is critical for diagnosis of neuronal ceroid lipofuscinosis and mucolipidosis IV and is the most cost-effective screening tool in patients with previously unrecognized storage diseases.
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Affiliation(s)
- Joseph Alroy
- Department of Pathology, Tufts University School of Medicine and Tufts-New England Medical Center, Boston, Massachusetts 02111, USA.
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Chen W, Yang S, Abe Y, Li M, Wang Y, Shao J, Li E, Li YP. Novel pycnodysostosis mouse model uncovers cathepsin K function as a potential regulator of osteoclast apoptosis and senescence. Hum Mol Genet 2007; 16:410-23. [PMID: 17210673 PMCID: PMC3578583 DOI: 10.1093/hmg/ddl474] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Pycnodysostosis is a genetic bone disease featuring the unique bone homeostasis disorders of osteolysis and osteopetrosis in the same organism. The pathomechanism for pycnodysostosis has been largely unknown due to the unavailability of a pycnodysostosis mouse model with all the traits of the disease. We generated cathepsin K(-/-) mouse strains in the 129/Sv and C57BL/6J backgrounds and found that, only in the 129/Sv background, cathepsin K(-/-) mice exhibit many characteristics of the human pycnodysostosis-like phenotype. Our data indicated that 129/Sv cathepsin K(-/-) osteoclasts (OCs) lacked normal apoptosis and senescence and exhibited over-growth both in vitro and in vivo. These abnormalities resulted in an unusually high OC number, which is consistent with a recent case study of human pycnodysostosis. Our results show that cathepsin K function has different effects around the skeleton due to site-specific variations in bone homeostasis, such as phenotypes of osteopetrosis in tibiae and osteolysis in calvariae as a result of cathepsin K mutation. Our data demonstrated that the expression levels of p19, p53 and p21 were significantly reduced in 129/Sv cathepsin K(-/-) OCs and forced expression of cathepsin K in pre-OCs induced premature senescence and increased expression of p19, p53 and p21. This is the first evidence that cathepsin K plays a key role in OC apoptosis and senescence, revealing the importance of OC senescence in bone homeostasis. The finding of this novel cathepsin K function provides insight into the pathomechanism of pycnodysostosis and may provide new drug targets for diseases involved in OC-related abnormal bone homeostasis.
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Affiliation(s)
- Wei Chen
- Department of Cytokine Biology, The Forsyth Institute & Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA
- Harvard-Forsyth Department of Oral Biology, The Forsyth Institute & Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA
| | - Shuying Yang
- Department of Cytokine Biology, The Forsyth Institute & Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA
- Harvard-Forsyth Department of Oral Biology, The Forsyth Institute & Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA
| | - Yoke Abe
- Department of Cytokine Biology, The Forsyth Institute & Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA
| | - Ming Li
- Department of Cytokine Biology, The Forsyth Institute & Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA
| | - Yucheng Wang
- Department of Cytokine Biology, The Forsyth Institute & Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA
| | - Jianzhong Shao
- Department of Cytokine Biology, The Forsyth Institute & Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA
- Life Science College, Zhejiang University, Hangzhou, China
| | - En Li
- Cardiovascular Research Center, Massachusetts General Hospital, Department of Medicine, Harvard Medical School, Charlestown, MA 02129, USA
| | - Yi-Ping Li
- Department of Cytokine Biology, The Forsyth Institute & Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA
- Harvard-Forsyth Department of Oral Biology, The Forsyth Institute & Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA
- To whom correspondence should be addressed: Tel: +1 6178928260; Fax: +1 6172624021;
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Weidauer E, Yasuda Y, Biswal BK, Cherny M, James MNG, Brömme D. Effects of disease-modifying anti-rheumatic drugs (DMARDs) on the activities of rheumatoid arthritis-associated cathepsins K and S. Biol Chem 2007; 388:331-6. [PMID: 17338641 DOI: 10.1515/bc.2007.037] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Rheumatoid arthritis is an inflammatory and disabling joint disease affecting 0.5-1.5% of the population. Although various anti-inflammatory (NSAIDs) and disease-modifying (DMARDs) drugs are in clinical use, their precise mechanisms of action are not always defined. In this report, we discuss the effects of widely used DMARDs such as gold derivatives and chloroquine on cathepsins K and S, which have been implicated as critical mediators of inflammation and joint erosion in rheumatoid arthritis. We demonstrate that clinically potent gold derivatives inhibit cathepsins K and S in in vitro and cell-based assays. An X-ray analysis of the gold thiomalate/cathepsin K complex reveals that the inhibitor is bound to the active-site cysteine residue of the protease. Chloroquine, a lysosomotropic agent of lower clinical potency than gold derivatives, inhibits neutral pH-labile cathepsins intracellularly, but does not affect the neutral pH-stable cathepsin S. The potent inhibition of cathepsins implicated in the pathogenesis of rheumatoid arthritis by gold derivatives may explain the therapeutic efficacy of these drugs.
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Affiliation(s)
- Enrico Weidauer
- Department of Human Genetics, Mount Sinai School of Medicine, New York, NY 10029, USA
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Sørensen MG, Henriksen K, Schaller S, Henriksen DB, Nielsen FC, Dziegiel MH, Karsdal MA. Characterization of osteoclasts derived from CD14+ monocytes isolated from peripheral blood. J Bone Miner Metab 2007; 25:36-45. [PMID: 17187192 DOI: 10.1007/s00774-006-0725-9] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 08/30/2006] [Indexed: 10/23/2022]
Abstract
Bone resorption is solely mediated by osteoclasts. Therefore, a pure osteoclast population is of high interest for the investigation of biological aspects of the osteoclasts, such as the direct effect of growth factors and hormones, as well as for testing and characterizing inhibitors of bone resorption. We have established a pure, stable, and reproducible system for purification of human osteoclasts from peripheral blood. We isolated CD14-positive (CD14+) monocytes using anti-CD14-coated beads. After isolation, the monocytes are differentiated into mature osteoclasts by stimulation with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappaB ligand (RANKL). Osteoclast formation was only observed in the CD14+ population, not in the CD14- population, and only in the presence of both M-CSF and RANKL, confirming that the CD14+ system is a pure population of osteoclast precursors. No expression of osteoclast markers was observed in the absence of RANKL, whereas RANKL dose-dependently induced the expression of cathepsin K, tartrate-resistant acid phosphatase (TRACP), and matrix metallo proteinase (MMP)-9. Furthermore, morphological characterization of the cells demonstrated that actin rings were only formed in the presence of RANKL. Moreover, the osteoclasts were capable of forming acidic resorption lacunae, and inhibitors of lysosomal acidification attenuated this process. Finally, we measured the response to known bone resorption inhibitors, and found that the osteoclasts were sensitive to these and thereby provided a robust and valid method for interpretation of the effect of antiresorptive compounds. In conclusion, we have established a robust assay for developing osteoclasts that can be used to study several biological aspects of the osteoclasts and which in combination with the resorption marker CTX-I provides a useful tool for evaluating osteoclast function in vitro.
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Everts V, Korper W, Hoeben KA, Jansen IDC, Bromme D, Cleutjens KBJM, Heeneman S, Peters C, Reinheckel T, Saftig P, Beertsen W. Osteoclastic bone degradation and the role of different cysteine proteinases and matrix metalloproteinases: differences between calvaria and long bone. J Bone Miner Res 2006; 21:1399-408. [PMID: 16939398 DOI: 10.1359/jbmr.060614] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
UNLABELLED Osteoclastic bone degradation involves the activity of cathepsin K. We found that in addition to this enzyme other, yet unknown, cysteine proteinases participate in digestion. The results support the notion that osteoclasts from different bone sites use different enzymes to degrade the collagenous bone matrix. INTRODUCTION The osteoclast resorbs bone by lowering the pH in the resorption lacuna, which is followed by secretion of proteolytic enzymes. One of the enzymes taken to be essential in resorption is the cysteine proteinase, cathepsin K. Some immunolabeling and enzyme inhibitor data, however, suggest that other cysteine proteinases and/or proteolytic enzymes belonging to the group of matrix metalloproteinases (MMPs) may participate in the degradation. In this study, we investigated whether, in addition to cathepsin K, other enzymes participate in osteoclastic bone degradation. MATERIALS AND METHODS In bones obtained from mice deficient for cathepsin K, B, or L or a combination of K and L, the bone-resorbing activity of osteoclasts was analyzed at the electron microscopic level. In addition, bone explants were cultured in the presence of different selective cysteine proteinase inhibitors and an MMP inhibitor, and the effect on resorption was assessed. Because previous studies showed differences in resorption by calvarial osteoclasts compared with those present in long bones, in all experiments, the two types of bone were compared. Finally, bone extracts were analyzed for the level of activity of cysteine proteinases and the effect of inhibitors hereupon. RESULTS The analyses of the cathepsin-deficient bone explants showed that, in addition to cathepsin K, calvarial osteoclasts use other cysteine proteinases to degrade bone matrix. It was also shown that, in the absence of cathepsin K, long bone osteoclasts use MMPs for resorption. Cathepsin L proved to be involved in the MMP-mediated resorption of bone by calvarial osteoclasts; in the absence of this cathepsin, calvarial osteoclasts do not use MMPs for resorption. Selective inhibitors of cathepsin K and other cysteine proteinases showed a stronger effect on calvarial resorption than on long bone resorption. CONCLUSIONS Our findings suggest that (1) cathepsin K-deficient long bone osteoclasts compensate the lack of this enzyme by using MMPs in the resorption of bone matrix; (2) cathepsin L is involved in MMP-mediated resorption by calvarial osteoclasts; (3) in addition to cathepsin K, other, yet unknown, cysteine proteinases are likely to participate in skull bone degradation; and finally, (4) the data provide strong additional support for the existence of functionally different bone-site specific osteoclasts.
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Affiliation(s)
- Vincent Everts
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam, Amsterdam, The Netherlands.
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Henriksen K, Sørensen MG, Nielsen RH, Gram J, Schaller S, Dziegiel MH, Everts V, Bollerslev J, Karsdal MA. Degradation of the organic phase of bone by osteoclasts: a secondary role for lysosomal acidification. J Bone Miner Res 2006; 21:58-66. [PMID: 16355274 DOI: 10.1359/jbmr.050905] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2005] [Revised: 07/18/2005] [Accepted: 08/31/2005] [Indexed: 02/07/2023]
Abstract
UNLABELLED Osteoclasts degrade bone matrix by secretion of hydrochloric acid and proteases. We studied the processes involved in the degradation of the organic matrix of bone in detail and found that lysosomal acidification is involved in this process and that MMPs are capable of degrading the organic matrix in the absence of cathepsin K. INTRODUCTION Osteoclasts resorb bone by secretion of acid by the vacuolar H+-adenosine triphosphatase (V-ATPase) and the chloride channel ClC-7, followed by degradation of the matrix, mainly collagen type I, by cathepsin K and possibly by matrix metalloproteinases (MMPs). However, the switch from acidification to proteolysis and the exact roles of both the ion transporters and the proteinases still remain to be studied. MATERIALS AND METHODS We isolated CD14+ monocytes from human peripheral blood from either controls or patients with autosomal dominant osteopetrosis type II (ADOII) caused by defective ClC-7 function and cultured them in the presence of RANKL and macrophage-colony stimulating factor (M-CSF) to generate osteoclasts. We decalcified cortical bovine bone slices and studied the osteoclasts with respect to morphology, markers, and degradation of the decalcified matrix in the presence of various inhibitors of osteoclast acidification and proteolysis, using normal calcified bone as a reference. RESULTS We found that ADOII osteoclasts not only have reduced resorption of the calcified matrix, but also 40% reduced degradation of the organic phase of bone. We found that both acidification inhibitors and cathepsin K inhibitors reduced degradation of the organic matrix by 40% in normal osteoclasts, but had no effect in the ADOII osteoclasts. Furthermore, we showed that inhibition of MMPs leads to a 70% reduction in the degradation of the organic bone matrix and that MMPs and cathepsin K have additive effects. Finally, we show that osteoclastic MMPs mediate release of the carboxyterminal telopeptide of type I collagen (ICTP) fragment in the absence of cathepsin K activity, and therefore, to some extent, are able to compensate for the loss of cathepsin K activity. CONCLUSIONS These data clearly show that osteoclastic acidification of the lysosomes plays a hitherto nonrecognized role in degradation of the organic matrix. Furthermore, these data shed light on the complicated interplay between acidification dependent and independent proteolytic processes, mediated by cathepsin K and the MMPs, respectively.
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Affiliation(s)
- Kim Henriksen
- Pharmos Bioscience, Nordic Bioscience and Center for Clinical and Basic Research A/S, Herlev, Denmark.
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Li M, Amizuka N, Takeuchi K, Freitas PHL, Kawano Y, Hoshino M, Oda K, Nozawa-Inoue K, Maeda T. Histochemical evidence of osteoclastic degradation of extracellular matrix in osteolytic metastasis originating from human lung small carcinoma (SBC-5) cells. Microsc Res Tech 2006; 69:73-83. [PMID: 16456838 DOI: 10.1002/jemt.20272] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The aim of this study was to assess the dynamics of osteoclast migration and the degradation of unmineralized extracellular matrix in an osteolytic metastasis by examining a well-standardized lung cancer metastasis model of nude mice. SBC-5 human lung small carcinoma cells were injected into the left cardiac ventricle of 6-week-old BALB/c nu/nu mice under anesthesia. At 25-30 days after injection, the animals were sacrificed and their femora and/or tibiae were removed for histochemical analyses. Metastatic lesions were shown to occupy a considerable area extending from the metaphyses to the bone marrow region. Tartrate resistant acid phosphatase (TRAPase)-positive osteoclasts were found in association with an alkaline phosphatase (ALPase)-positive osteoblastic layer lining the bone surface, but could also be localized in the ALPase-negative stromal tissues that border the tumor nodules. These stromal tissues were markedly positive for osteopontin, and contained a significant number of TRAPase-positive osteoclasts expressing immunoreactivity for CD44. We thus speculated that, mediating its affinity for CD44, osteopontin may serve to facilitate osteoclastic migration after their formation associated with ALPase-positive osteoblasts. We next examined the localization of cathepsin K and matrix metallo-proteinase-9 (MMP-9) in osteoclasts. Osteoclasts adjacent to the bone surfaces were positive for both proteins, whereas those in the stromal tissues in the tumor nests showed only MMP-9 immunoreactivity. Immunoelectron microscopy disclosed the presence of MMP-9 in the Golgi apparatus and in vesicular structures at the baso-lateral cytoplasmic region of the osteoclasts found in the stromal tissue. MMP-9-positive vesicular structures also contained fragmented extracellular materials. Thus, osteoclasts appear to either select an optimized function, namely secreting proteolytic enzymes from ruffled borders during bone resorption, or recognize the surrounding extracellular matrix by mediating osteopontin/CD44 interaction, and internalize the extracellular matrices. Microsc.
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Affiliation(s)
- Minqi Li
- Division of Oral Anatomy, Niigata University Graduate School of Medical and Dental Sciences, Niigata, 951-8514, Japan
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Brage M, Abrahamson M, Lindström V, Grubb A, Lerner UH. Different cysteine proteinases involved in bone resorption and osteoclast formation. Calcif Tissue Int 2005; 76:439-47. [PMID: 15906014 DOI: 10.1007/s00223-004-0043-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2004] [Accepted: 01/13/2005] [Indexed: 02/05/2023]
Abstract
Cysteine proteinases, especially cathepsin K, play an important role in osteoclastic degradation of bone matrix proteins and the process can, consequently, be significantly inhibited by cysteine proteinase inhibitors. We have recently reported that cystatin C and other cysteine proteinase inhibitors also reduce osteoclast formation. However, it is not known which cysteine proteinase(s) are involved in osteoclast differentiation. In the present study, we compared the relative potencies of cystatins C and D as inhibitors of bone resorption in cultured mouse calvariae, osteoclastogenesis in mouse bone marrow cultures, and cathepsin K activity. Inhibition of cathepsin K activity was assessed by determining equilibrium constants for inhibitor complexes in fluorogenic substrate assays. The data demonstrate that whereas human cystatins C and D are equipotent as inhibitors of bone resorption, cystatin D is 10-fold less potent as an inhibitor of osteoclastogenesis and 200-fold less potent as an inhibitor of cathepsin K activity. A recombinant human cystatin C variant with Gly substitutions for residues Arg8, Leu9, Val10, and Trp106 did not inhibit bone resorption, had 1,000-fold decreased inhibitory effect on cathepsin K activity compared to wildtype cystatin C, but was equipotent with wildtype cystatin C as an inhibitor of osteoclastogenesis. It is concluded that (i) different cysteine proteinases are likely to be involved in bone resorption and osteoclast formation, (ii) cathepsin K may not be an exclusive target enzyme in any of the two systems, and (iii) the enzyme(s) involved in osteoclastogenesis might not be a typical papain-like cysteine proteinase.
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Affiliation(s)
- M Brage
- Department of Oral Cell Biology, Umeå University, S-90187 Umeå, Sweden
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Kiviranta R, Morko J, Alatalo SL, NicAmhlaoibh R, Risteli J, Laitala-Leinonen T, Vuorio E. Impaired bone resorption in cathepsin K-deficient mice is partially compensated for by enhanced osteoclastogenesis and increased expression of other proteases via an increased RANKL/OPG ratio. Bone 2005; 36:159-72. [PMID: 15664014 DOI: 10.1016/j.bone.2004.09.020] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Revised: 09/15/2004] [Accepted: 09/27/2004] [Indexed: 01/06/2023]
Abstract
Previous reports indicate that mice deficient for cathepsin K (Ctsk), a key protease in osteoclastic bone resorption, develop osteopetrosis due to their inability to properly degrade organic bone matrix. Some features of the phenotype of Ctsk knockout mice, however, suggest the presence of mechanisms by which Ctsk-deficient mice compensate for the lack of cathepsin K. To study these mechanisms in detail, we generated Ctsk-deficient (Ctsk-/-) mice and analyzed them at the age of 2, 7, and 12 months using peripheral quantitative computed tomography, histomorphometry, resorption marker measurements, osteoclast and osteoblast differentiation cultures, and gene expression analyses. The present study verified the previously published osteopetrotic features of Ctsk-deficient mice. However, these changes did not exacerbate during aging indicating the absence of Ctsk to have its most severe effects during the rapid growth period. Resorption markers ICTP and CTX were decreased in the media of Ctsk-/- osteoclasts cultured on bone slices indicating impaired bone resorption. Ctsk-/- mice exhibited several mechanisms attempting to compensate for Ctsk deficiency. The number of osteoclasts in trabecular bone was significantly increased in Ctsk-/- mice compared to controls, as was the number of osteoclast precursors in bone marrow. The mRNA levels for receptor activator of nuclear factor (kappa)B ligand (RANKL) in Ctsk-/- bones were increased resulting in increased RANKL/OPG ratio favoring osteoclastogenesis. In addition, expression of mRNAs of osteoclastic enzymes (MMP-9, TRACP) and for osteoblastic proteases (MMP-13, MMP-14) were increased in Ctsk-/- mice compared to controls. Impaired osteoclastic bone resorption in Ctsk-/- mice results in activation of osteoblastic cells to produce increased amounts of other proteolytic enzymes and RANKL in vivo. We suggest that increased RANKL expression mediates enhanced osteoclastogenesis and increased protease expression by osteoclasts. These observations underline the important role of osteoblastic cells in regulation of osteoclast activity and bone turnover.
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Affiliation(s)
- Riku Kiviranta
- Department of Medical Biochemistry and Molecular Biology, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland
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Brand HS, Lerner UH, Grubb A, Beertsen W, Nieuw Amerongen AV, Everts V. Family 2 cystatins inhibit osteoclast-mediated bone resorption in calvarial bone explants. Bone 2004; 35:689-96. [PMID: 15336605 DOI: 10.1016/j.bone.2004.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Revised: 05/12/2004] [Accepted: 05/14/2004] [Indexed: 10/26/2022]
Abstract
Osteoclastic bone resorption depends on the activity of various proteolytic enzymes, in particular those belonging to the group of cysteine proteinases. Biochemical studies have shown that cystatins, naturally occurring inhibitors of these enzymes, inhibit bone matrix degradation. Since the mechanism by which cystatins exert this inhibitory effect is not completely resolved yet, we studied the effect of cystatins on bone resorption microscopically and by Ca-release measurements. Calvarial bone explants were cultured in the presence or absence of family 2 cystatins and processed for light and electron microscopic analysis, and the culture media were analyzed for calcium release. Both egg white cystatin and human cystatin C decreased calcium release into the medium significantly. Microscopic analyses of the bone explants demonstrated that in the presence of either inhibitor, a high percentage of osteoclasts was associated with demineralized non-degraded bone matrix. Following a 24-h incubation in the presence of cystatin C, 41% of the cells were adjacent to areas of demineralized non-degraded bone matrix, whereas in controls, this was only 6%. If bone explants were cultured with both PTH and cystatin C, 60% of the osteoclasts were associated with demineralized non-degraded bone matrix, compared to 27% for bones treated with PTH only (P < 0.01). Our study provides evidence that cystatins, the naturally occurring inhibitors of cysteine proteinases, reversibly inhibit bone matrix degradation in the resorption lacunae adjacent to osteoclasts. These findings suggest the involvement of cystatins in the modulation of osteoclastic bone degradation.
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Affiliation(s)
- H S Brand
- Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam, Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands.
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Wang D, Li W, Pechar M, Kopecková P, Brömme D, Kopecek J. Cathepsin K inhibitor–polymer conjugates: potential drugs for the treatment of osteoporosis and rheumatoid arthritis. Int J Pharm 2004; 277:73-9. [PMID: 15158970 DOI: 10.1016/j.ijpharm.2003.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2002] [Revised: 02/05/2003] [Accepted: 03/23/2003] [Indexed: 10/26/2022]
Abstract
The role of the newly discovered cysteine protease, cathepsin K, in osteoporosis and rheumatoid arthritis is reviewed. The current development of cathepsin K inhibitors and their targeted delivery using synthetic polymer carriers are discussed. Future challenges and possible strategies to improve these delivery systems are addressed.
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Affiliation(s)
- D Wang
- Department of Pharmaceutics and Pharmaceutical Chemistry/CCCD, University of Utah, 30 S 2000 E Rm. 301, Salt Lake City, UT 84112, USA
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Li Z, Yasuda Y, Li W, Bogyo M, Katz N, Gordon RE, Fields GB, Brömme D. Regulation of Collagenase Activities of Human Cathepsins by Glycosaminoglycans. J Biol Chem 2004; 279:5470-9. [PMID: 14645229 DOI: 10.1074/jbc.m310349200] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cathepsin K, a lysosomal papain-like cysteine protease, forms collagenolytically highly active complexes with chondroitin sulfate and represents the most potent mammalian collagenase. Here we demonstrate that complex formation with glycosaminoglycans (GAGs) is unique for cathepsin K among human papain-like cysteine proteases and that different GAGs compete for the binding to cathepsin K. GAGs predominantly expressed in bone and cartilage, such as chondroitin and keratan sulfates, enhance the collagenolytic activity of cathepsin K, whereas dermatan, heparan sulfate, and heparin selectively inhibit this activity. Moreover, GAGs potently inhibit the collagenase activity of other cysteine proteases such as cathepsins L and S at 37 degrees C. Along this line MMP1-generated collagen fragments in the presence of GAGs are stable against further degradation at 28 degrees C by all cathepsins but cathepsin K, whereas thermal destabilization at 37 degrees C renders the fragments accessible to all cathepsins. These results suggest a novel mechanism for the regulation of matrix protein degradation by GAGs. It further implies that cathepsin K represents the only lysosomal collagenolytic activity under physiologically relevant conditions.
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Affiliation(s)
- Zhenqiang Li
- Mount Sinai School of Medicine, Department of Human Genetics, New York, New York 10029, USA
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Mulari M, Vääräniemi J, Väänänen HK. Intracellular membrane trafficking in bone resorbing osteoclasts. Microsc Res Tech 2003; 61:496-503. [PMID: 12879417 DOI: 10.1002/jemt.10371] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
There is ample evidence now that the two major events in bone resorption, namely dissolution of hydroxyapatite and degradation of the organic matrix, are performed by osteoclasts. The resorption cycle involves several specific cellular activities, where intracellular vesicular trafficking plays a crucial role. Although details of these processes started to open up only recently, it is clear that vesicular trafficking is needed in several specific steps of osteoclast functioning. Several plasma membrane domains are formed during the polarization of the resorbing cells. Multinucleated osteoclasts create a tight sealing to the extracellular matrix as a first indicator of their resorption activity. Initial steps of the sealing zone formation are alpha(v)beta(3)-integrin mediated, but the final molecular interaction(s) between the plasma membrane and mineralized bone matrix is still unknown. A large number of acidic intracellular vesicles then fuse with the bone-facing plasma membrane to form a ruffled border membrane, which is the actual resorbing organelle. The formation of a ruffled border is regulated by a small GTP-binding protein, rab7, which indicates the late endosomal character of the ruffled border membrane. Details of specific membrane transport processes in the osteoclasts, e.g., the formation of the sealing zone and transcytosis of bone degradation products from the resorption lacuna to the functional secretory domain remain to be clarified. It is tempting to speculate that specific features of vesicular trafficking may offer several potential new targets for drug therapy of bone diseases.
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Affiliation(s)
- Mika Mulari
- Department of Anatomy, Institute of Biomedicine, University of Turku, 20520 Turku, Finland
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