1
|
Wang J, Li J, Zhong L. Current status and prospect of anti-amyloid fibril therapy in AL amyloidosis. Blood Rev 2024; 66:101207. [PMID: 38692939 DOI: 10.1016/j.blre.2024.101207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 04/11/2024] [Accepted: 04/14/2024] [Indexed: 05/03/2024]
Abstract
Amyloid light-chain (AL) amyloidosis is a rare hematological disease that produces abnormal monoclonal immunoglobulin light chains to form amyloid fibrils that are deposited in tissues, resulting in organ damage and dysfunction. Advanced AL amyloidosis has a very poor prognosis with a high risk of early mortality. The combination of anti-plasma cell therapy and amyloid fibrils clearance is the optimal treatment strategy, which takes into account both symptoms and root causes. However, research on anti-amyloid fibrils lags far behind research on anti-plasma cells, and there is currently no approved treatment that could clear amyloid fibrils. Nevertheless, anti-amyloid fibril therapies are being actively investigated recently and have shown potential in clinical trials. In this review, we aim to outline the preclinical work and clinical efficacy of fibril-directed therapies for AL amyloidosis.
Collapse
Affiliation(s)
- Jinghua Wang
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Jian Li
- Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Liye Zhong
- Department of Hematology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China.
| |
Collapse
|
2
|
Mehta D, Singh H, Haridas V, Chaudhuri TK. Molecular Insights into the Inhibition of Dialysis-Related β2m Amyloidosis Orchestrated by a Bispidine Peptidomimetic Analogue. Biochemistry 2022; 61:1473-1484. [PMID: 35749234 DOI: 10.1021/acs.biochem.2c00205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dialysis-related amyloidosis (DRA) is considered an inescapable consequence of renal failure. Upon prolonged hemodialysis, it involves accumulation of toxic β2-microglobulin (β2m) amyloids in bones and joints. Current treatment methods are plagued with high cost, low specificity, and low capacity. Through our in vitro and in cellulo studies, we introduce a peptidomimetic-based approach to help develop future therapeutics against DRA. Our study reports the ability of a nontoxic, core-modified, bispidine peptidomimetic analogue "B(LVI)2" to inhibit acid-induced amyloid fibrillation of β2m (Hβ2m). Using thioflavin-T, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and transmission electron microscopy analysis, we demonstrate that B(LVI)2 delays aggregation lag time of Hβ2m amyloid fibrillation and reduces the yield of Hβ2m amyloid fibrils in a dose-dependent manner. Our findings suggest a B(LVI)2-orchestrated alteration in the route of Hβ2m amyloid fibrillation resulting in the formation of noncytotoxic, morphologically distinct amyloid-like species. Circular dichroism data show gradual sequestration of Hβ2m species in a soluble nonamyloidogenic noncytotoxic conformation in the presence of B(LVI)2. Dynamic light scattering measurements indicate incompetence of Hβ2m species in the presence of B(LVI)2 to undergo amyloid-competent intermolecular associations. Overall, our study reports the antifibrillation property of a novel peptidomimetic with the potential to bring a paradigm shift in therapeutic approaches against DRA.
Collapse
Affiliation(s)
- Devanshu Mehta
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Hanuman Singh
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - V Haridas
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Tapan K Chaudhuri
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi 110016, India
| |
Collapse
|
3
|
Hoop CL, Zhu J, Bhattacharya S, Tobita CA, Radford SE, Baum J. Collagen I Weakly Interacts with the β-Sheets of β 2-Microglobulin and Enhances Conformational Exchange To Induce Amyloid Formation. J Am Chem Soc 2020; 142:1321-1331. [PMID: 31875390 PMCID: PMC7135851 DOI: 10.1021/jacs.9b10421] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
![]()
Amyloidogenesis is
significant in both protein function and pathology.
Amyloid formation of folded, globular proteins is commonly initiated
by partial or complete unfolding. However, how this unfolding event
is triggered for proteins that are otherwise stable in their native
environments is not well understood. The accumulation of the immunoglobulin
protein β2-microglobulin (β2m) into
amyloid plaques in the joints of long-term hemodialysis patients is
the hallmark of dialysis-related amyloidosis (DRA). While β2m does not form amyloid unassisted near neutral pH in vitro, the localization of β2m deposits
to joint spaces suggests a role for the local extracellular matrix
(ECM) proteins, specifically collagens, in promoting amyloid formation.
Indeed, collagen and other ECM components have been observed to facilitate
β2m amyloid formation, but the large size and anisotropy
of the complex, combined with the low affinity of these interactions,
have limited atomic-level elucidation of the amyloid-promoting mechanism(s)
by these molecules. Using solution NMR approaches that uniquely probe
weak interactions in large molecular weight complexes, we are able
to map the binding interfaces on β2m for collagen
I and detect collagen I-induced μs–ms time-scale dynamics
in the β2m backbone. By combining solution NMR relaxation
methods and 15N-dark-state exchange saturation transfer
experiments, we propose a model in which weak, multimodal collagen
I−β2m interactions promote exchange with a
minor population of amyloid-competent species to induce fibrillogenesis.
The results portray the intimate role of the environment in switching
an innocuous protein into an amyloid-competent state, rationalizing
the localization of amyloid deposits in DRA.
Collapse
Affiliation(s)
- Cody L Hoop
- Department of Chemistry and Chemical Biology , Rutgers University , Piscataway , New Jersey 08854 , United States
| | - Jie Zhu
- Department of Chemistry and Chemical Biology , Rutgers University , Piscataway , New Jersey 08854 , United States
| | | | - Caitlyn A Tobita
- Department of Chemistry and Chemical Biology , Rutgers University , Piscataway , New Jersey 08854 , United States
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, Faculty of Biological Sciences , University of Leeds , Leeds LS2 9JT , U.K
| | - Jean Baum
- Department of Chemistry and Chemical Biology , Rutgers University , Piscataway , New Jersey 08854 , United States
| |
Collapse
|
4
|
Benseny-Cases N, Karamanos TK, Hoop CL, Baum J, Radford SE. Extracellular matrix components modulate different stages in β 2-microglobulin amyloid formation. J Biol Chem 2019; 294:9392-9401. [PMID: 30996004 PMCID: PMC6579475 DOI: 10.1074/jbc.ra119.008300] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/09/2019] [Indexed: 11/26/2022] Open
Abstract
Amyloid deposition of WT human β2-microglobulin (WT-hβ2m) in the joints of long-term hemodialysis patients is the hallmark of dialysis-related amyloidosis. In vitro, WT-hβ2m does not form amyloid fibrils at physiological pH and temperature unless co-solvents or other reagents are added. Therefore, understanding how fibril formation is initiated and maintained in the joint space is important for elucidating WT-hβ2m aggregation and dialysis-related amyloidosis onset. Here, we investigated the roles of collagen I and the commonly administered anticoagulant, low-molecular-weight (LMW) heparin, in the initiation and subsequent aggregation phases of WT-hβ2m in physiologically relevant conditions. Using thioflavin T fluorescence to study the kinetics of amyloid formation, we analyzed how these two agents affect specific stages of WT-hβ2m assembly. Our results revealed that LMW-heparin strongly promotes WT-hβ2m fibrillogenesis during all stages of aggregation. However, collagen I affected WT-hβ2m amyloid formation in contrasting ways: decreasing the lag time of fibril formation in the presence of LMW-heparin and slowing the rate at higher concentrations. We found that in self-seeded reactions, interaction of collagen I with WT-hβ2m amyloid fibrils attenuates surface-mediated growth of WT-hβ2m fibrils, demonstrating a key role of secondary nucleation in WT-hβ2m amyloid formation. Interestingly, collagen I fibrils did not suppress surface-mediated assembly of WT-hβ2m monomers when cross-seeded with fibrils formed from the N-terminally truncated variant ΔN6-hβ2m. Together, these results provide detailed insights into how collagen I and LMW-heparin impact different stages in the aggregation of WT-hβ2m into amyloid, which lead to dramatic effects on the time course of assembly.
Collapse
Affiliation(s)
- Núria Benseny-Cases
- From the Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom and
| | - Theodoros K Karamanos
- From the Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom and
| | - Cody L Hoop
- the Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854
| | - Jean Baum
- the Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854
| | - Sheena E Radford
- From the Astbury Centre for Structural Molecular Biology and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom and
| |
Collapse
|
5
|
Yanagisawa A, Ueda M, Sueyoshi T, Nakamura E, Tasaki M, Suenaga G, Motokawa H, Toyoshima R, Kinoshita Y, Misumi Y, Yamashita T, Sakaguchi M, Westermark P, Mizuta H, Ando Y. Knee osteoarthritis associated with different kinds of amyloid deposits and the impact of aging on type of amyloid. Amyloid 2016; 23:26-32. [PMID: 26701417 DOI: 10.3109/13506129.2015.1115758] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Amyloidosis is a protein conformational disorder in which amyloid fibrils accumulate in the extracellular space and induce organ dysfunction. Recently, two different amyloidogenic proteins, transthyretin (TTR) and apolipoprotein A-I (Apo A-I), were identified in amyloid deposits in knee joints in patients with knee osteoarthritis (OA). However, clinicopathological differences related to those two kinds of amyloid deposits in the knee joint remain to be clarified. Here, we investigated the clinicopathological features related to these knee amyloid deposits associated with knee OA and the biochemical characteristics of the amyloid deposits. We found that all of our patients with knee OA had amyloid deposits in the knee joints, especially in the meniscus, and those deposits were primarily derived from TTR and/or Apo A-I. Some patients with knee OA, however, had unclassified amyloid deposits. One of our interesting observations concerned the different effects of aging on each type of amyloid formed. The frequency of formation of ATTR deposits clearly increased with age, but that of AApo A-I deposits decreased. Furthermore, we found that ∼16% of patients with knee OA developed ATTR/AApo A-I double deposits in the meniscus. Amyloid deposition may therefore be a common histopathological feature associated with knee OA. Also, aging may induce ATTR formation in the knee joint in elderly patients with knee OA, whereas AApo A-I formation may be inversely correlated with age.
Collapse
Affiliation(s)
- Akihiro Yanagisawa
- a Department of Orthopaedic Surgery , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .,b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Mitsuharu Ueda
- b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Takanao Sueyoshi
- a Department of Orthopaedic Surgery , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Eiichi Nakamura
- a Department of Orthopaedic Surgery , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Masayoshi Tasaki
- b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Genki Suenaga
- b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Hiroaki Motokawa
- b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Risa Toyoshima
- b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Yumiko Kinoshita
- b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Yohei Misumi
- b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Taro Yamashita
- b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | | | - Per Westermark
- d Department of Immunology , Genetics and Pathology, Uppsala University , Uppsala , Sweden
| | - Hiroshi Mizuta
- a Department of Orthopaedic Surgery , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| | - Yukio Ando
- b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan
| |
Collapse
|
6
|
Abstract
Amyloidosis comprises a group of diseases characterized by the extracellular deposition of insoluble fibrillar proteins. This mechanism generates different clinical syndromes depending on the site and extent of organ involvement. Amyloidosis is classified into categories of systemic and localized disease. Systemic amyloidosis is further subdivided into a hereditary familial form (for example, ATTR amyloidosis), a reactive form (AA amyloidosis), dialysis-related (Abeta(2)M) amyloidosis and immunoglobulin light chain (AL) amyloidosis. Treatment can be symptomatic, directed at the affected organ, or can be directed at reducing the production of the abnormal proteins with different strategies. Despite advances in treatment, the prognosis is still poor and depends on the underlying disease as well as the type and degree of dysfunction in involved organs. Early diagnosis is essential because patients with advanced disease are generally unable to undergo intensive therapy. Patients with systemic amyloidosis often present to a rheumatologist not only because the disease can include musculoskeletal and articular symptoms but also because it can be associated with chronic rheumatic diseases. This Review discusses the clinical features of amyloidosis and its rheumatic manifestations. The various types of amyloidosis, as well their prognosis and treatment, are also presented.
Collapse
|
7
|
Sunk IG, Demetriou D, Szendroedi J, Amoyo L, Raffetseder A, Hörl WH, Sunder-Plassmann G, Smolen JS, Bobacz K. Cartilage biomarkers in hemodialysis patients and the effect of beta2-microglobulin on articular chondrocytes. Osteoarthritis Cartilage 2008; 16:1336-42. [PMID: 18457963 DOI: 10.1016/j.joca.2008.03.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Accepted: 03/30/2008] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Dialysis-related amyloidosis (DRA) is a severe complication of maintenance hemodialysis (HD). Given the predominant deposition of beta(2)-microglobulin (beta2m) fibrils on articular cartilage in early DRA, we investigated the significance of beta2m and its relationship to distinct cartilage biomarkers in early DRA diagnosis in HD patients. Furthermore, we assessed the effects of beta2m on articular chondrocytes in vitro. METHODS Serum samples from 133 patients were collected before and after HD. Type II collagen cleavage product (C2C), procollagen II c-propeptide (CPII), aggrecan chondroitin sulfate 846 epitope (CS-486) and cartilage oligomeric matrix protein (COMP) levels were determined by enzyme-linked immunosorbent assay. Primary bovine articular chondrocytes were cultured as monolayers and incubated with beta2m at 1.5mg/l and 20mg/l. Cartilage glucosaminoglycan synthesis was measured by [(35)S]sulfate incorporation. mRNA expression of interleukin (IL)-1beta, matrix metalloproteinases (MMPs)-3 and -9 was measured by reverse-transcriptase polymerase chain reaction (RT-PCR). RESULTS Incubation with beta2m at 20mg/l significantly decreased matrix biosynthesis. PCR analysis revealed an increase of IL-1beta, as well as MMPs-3 and -9 on the mRNA level. C2C/CPII, CS-486 and COMP levels were increased only in a subset of patients without a significant correlation with beta2m concentrations. A subgroup analysis elucidated an increase in type II collagen degradation during the first years of HD, as shown by the elevation of C2C/CPII ratio. CONCLUSION beta2m exerted anti-anabolic effects on articular chondrocytes in vitro and might be involved in cartilage degradation in HD patients. beta2m serum levels, however, did not reflect cartilage degradation in DRA. The assessment of C2C/CPII, CS-486 or COMP concentrations apparently has minor relevance in DRA diagnosis in HD patients. However, the increased type II collagen breakdown within 5 years after HD onset possibly mirrors the early stages of DRA. Thus, the C2C/CPII ratio could be employed in longitudinal studies, since it may reflect a risk for DRA related arthropathy development in a subset of patients.
Collapse
Affiliation(s)
- I-G Sunk
- Department of Internal Medicine III, Division of Rheumatology, Medical University of Vienna, Austria
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Abstract
Dialysis-related amyloidosis is a complication of end-stage renal disease (ESRD) that results from retention of beta2-microglobulin (beta2M) and its deposition as amyloid fibrils into osteoarticular tissue. The clinical manifestations usually develop after several years of dialysis dependence and include carpal tunnel syndrome, destructive arthropathy, and bone cysts and fractures. High-flux membranes, daily dialysis, and hemofiltration all would be expected to delay the onset of dialysis-related amyloidosis because, to varying degrees, each increases the clearance of beta2M from the plasma. Thus what is currently a late complication of ESRD might become an even later complication as dialysis practices change. The significance of histologically evident but clinically silent beta2M amyloid, detectable not only in osteoarticular tissue but also in blood vessels, is unclear. Accumulating evidence that amyloidogenic proteins have direct and specific effects on cell processes irrespective of the extent of amyloid deposition raises the possibility that early, clinically silent beta2M amyloid deposits have unrecognized importance.
Collapse
Affiliation(s)
- Laura M Dember
- Renal Section, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
| | | |
Collapse
|
9
|
Obici L, Perfetti V, Palladini G, Moratti R, Merlini G. Clinical aspects of systemic amyloid diseases. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1753:11-22. [PMID: 16198646 DOI: 10.1016/j.bbapap.2005.08.014] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Revised: 08/19/2005] [Accepted: 08/20/2005] [Indexed: 11/30/2022]
Abstract
Amyloidosis is a protein misfolding disorder in which soluble proteins aggregate as insoluble amyloid fibrils. Protein aggregates and amyloid fibrils cause functional and structural organ damage respectively. To date, at least 24 different proteins have been recognized as causative agents of amyloid diseases, localized or systemic. The two most common forms of systemic amyloidosis are light-chain (AL) amyloidosis and reactive AA amyloidosis due to chronic inflammatory diseases. beta(2)-microglobulin amyloidosis is a common complication associated with long-term hemodialysis. Hereditary systemic amyloidoses are a group of autosomal dominant disorders caused by mutations in the genes of several plasma proteins. Heterogeneity in clinical presentation, pattern of amyloid-related organ toxicity and rate of disease progression is observed among systemic amyloidoses. In particular, beta(2)-microglobulin presents unique clinical features compared to the other systemic forms. The phenotypic features of hereditary systemic amyloidoses may instead overlap those of the two more common forms of acquired amyloidoses mentioned above and therefore a correct diagnosis can not rely only on clinical grounds. Unequivocal identification of the deposited protein is essential in order to avoid misdiagnosis and inappropriate treatment. Amyloid deposits can be reabsorbed and organ dysfunction reversed if the concentration of the amyloidogenic protein is reduced or zeroed. At present, the most effective approach to treatment of the systemic amyloidoses involves shutting down, or substantially reducing the synthesis of the amyloid precursor, or, as in the case of beta(2)-microglobulin, promoting its clearance.
Collapse
Affiliation(s)
- Laura Obici
- Amyloid Center, Biotechnology Research Laboratories, IRCCS Policlinico San Matteo, Pavia, Italy
| | | | | | | | | |
Collapse
|
10
|
Giorgetti S, Rossi A, Mangione P, Raimondi S, Marini S, Stoppini M, Corazza A, Viglino P, Esposito G, Cetta G, Merlini G, Bellotti V. Beta2-microglobulin isoforms display an heterogeneous affinity for type I collagen. Protein Sci 2005; 14:696-702. [PMID: 15689502 PMCID: PMC2279294 DOI: 10.1110/ps.041194005] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
It has been claimed that beta2-microglobulin (beta2-m) interacts with type I and type II collagen, and this property has been linked to the tissue specificity of the beta2-m amyloid deposits that target the osteo-articular system. The binding parameters of the interaction between collagen and beta2-m were determined by band shift electrophoresis and surface plasma resonance by using bovine collagen of type I and type II and various isoforms of beta2-m. Wild-type beta2-m binds collagen type I with a Kd of 4.1 x 10(-4) M and type II with 2.3 x 10(-3) M. By the BIAcore system we monitored the binding properties of the conformers of the slow phase of folding of beta2-m. The folding intermediates during the slow phase of folding do not display any significant difference with respect to the binding properties of the fully folded molecule. The affinity of beta2-m truncated at the third N-terminal residue does not differ from that reported for the wild-type protein. Increased affinity for collagen type I is found in the case of N-terminal truncated species lacking of six residues. The Kd of this species is 3.4 x 10 (-5) M at pH 7.4 and its affinity increases to 4.9 x 10(-6) M at pH 6.4. Fluctuations of the affinity caused by beta2-m truncation and pH change can cause modifications of protein concentration in the solvent that surrounds the collagen, and could contribute to generate locally a critical protein concentration able to prime the protein aggregation.
Collapse
Affiliation(s)
- Sofia Giorgetti
- Dipartimento di Biochimica, Università degli Studi di Pavia, via Taramelli 3/b 27100 Pavia, Italy
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
PURPOSE OF REVIEW Macrophage infiltration is a distinctive histological characteristic of beta2-microglobulin amyloidosis. Studies reported during the past years have helped to clarify the role of monocytes/macrophages in the fibrillar precipitation of beta2-microglobulin and in the pathogenesis of osteoarticular pathology. RECENT FINDINGS Contrary to the original view, macrophage infiltration is more likely a secondary phenomenon of amyloidosis rather than an initiating event. The observation that macrophages are associated with a later stage of beta2-microglobulin amyloidosis suggests a possible role of these cells in transformation of clinical silent deposits into symptomatic osteoarticular destruction. Accumulating evidence suggests that beta2-microglobulin modified with advanced glycation end products plays a key role in recruitment and activation of macrophages through an advanced glycation end products receptor-mediated pathway, and thus may contribute to the development of local cellular inflammation in beta2-microglobulin amyloidosis. SUMMARY Beta 2-microglobulin amyloidosis arthropathies may result from progressive accumulation of advanced glycation end products in long-lived amyloid linked to a heightened cellular response. Antagonism of the interaction between advanced glycation end products and their receptor may be a relevant strategy for cellular inflammation in beta2-microglobulin amyloidosis.
Collapse
Affiliation(s)
- Fan Fan Hou
- Division of Nephrology, Nanfang Hospital, Guangzhou, People's Republic of China.
| | | |
Collapse
|
12
|
Chen NX, O'Neill KD, Niwa T, Moe SM. Signal transduction of beta2m-induced expression of VCAM-1 and COX-2 in synovial fibroblasts. Kidney Int 2002; 61:414-24. [PMID: 11849381 DOI: 10.1046/j.1523-1755.2002.00136.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND beta2 microglobulin (beta2m) amyloidosis is a destructive articular disease affecting dialysis patients. We have demonstrated that beta2m increases the expression of vascular cell adhesion molecule (VCAM-1) and cyclooxygenase-2 (COX-2) in human osteoarthritic synovial fibroblasts (SFLs). METHODS To determine the cell signaling pathways, SFLs were incubated with beta2m in the presence or absence of various inhibitors for 24 hours. Intracellular calcium ([Ca2+]i) was measured by fluorometric techniques and vascular cell adhesion molecule-1 (VCAM-1) and cyclooxygenase-2 (COX-2) expression was determined by immunohistochemistry and Western blotting. RESULTS beta2m increased [Ca2+]i levels in a dose dependent manner (P < 0.05) in SFLs. BAPTA-AM, a [Ca2+]i chelator, completely inhibited beta2m-induced expression of VCAM-1 and COX-2. U73122 [phospholipase C (PLC) inhibitor] or 2-APB [specific inhibitor of inositol 1,4,5-trisphosphate (IP3)-induced [Ca2+]i release] completely blocked the beta2m-induced increase in [Ca2+]i and the up-regulation of VCAM-1 and COX-2. However, pretreatment with staurosporin, a protein kinase C inhibitor, had no effect. Disruption of the actin cytoskeleton by treatment with cytochalasin D or latrunculin A blocked beta2m up-regulation of VCAM-1 and COX-2. Finally, cells treated with phosphatidylinositol-3 kinase (PI-3 kinase) inhibitors wortmannin or LY294002 also failed to express VCAM-1 and COX-2. CONCLUSIONS These results demonstrate that IP3-mediated [Ca2+]i release, PI-3 kinase, and actin cytoskeleton reorganization are involved in beta2m-induced expression of VCAM-1 and COX-2 in human SFLs. Understanding the potential pathways by which beta2m exerts its inflammatory-like effects may lead to the development of future therapies.
Collapse
Affiliation(s)
- Neal X Chen
- Indiana University School of Medicine and Richard L. Roudebush VAMC, Indianapolis, Indiana, USA.
| | | | | | | |
Collapse
|