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Annunziata I, d'Azzo A. Galactosialidosis: historic aspects and overview of investigated and emerging treatment options. Expert Opin Orphan Drugs 2016; 5:131-141. [PMID: 28603679 DOI: 10.1080/21678707.2016.1266933] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Galactosialidosis is a glycoprotein storage disease caused by mutations in the CTSA gene, encoding lysosomal protective protein/cathepsin A (PPCA). The enzyme's catalytic activity is distinct from its protective function towards β-galactosidase (β-GAL) and neuraminidase 1 (NEU1), with which PPCA forms a complex. In this configuration the two glycosidases acquire their full activity and stability in lysosomes. Deficiency of PPCA results in combined NEU1/β-GAL deficiency. Because of its low incidence, galactosialidosis is considered an orphan disorder with no therapy yet available. AREAS COVERED This review gives a historic overview on the discovery of PPCA, which defined galactosialidosis as a new clinical entity; the evidence for the existence of the PPCA/NEU1/β-GAL complex; the clinical forms of galactosialidosis and disease-causing CTSA mutations. Ppca-/- mice have proven to be a suitable model to test different therapeutic approaches, paving the way for the development of clinical trials for patients with galactosialidosis. EXPERT OPINION Improved understanding of the molecular bases of disease has sparked renewed incentive from clinicians and scientists alike to develop therapies for rare conditions, like GS, and has increased the willingness of biotech companies to invest in the manufacturing of new therapeutics. Both ERT and gene therapy may become available to patients in the near future.
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Affiliation(s)
- Ida Annunziata
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Alessandra d'Azzo
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN, USA
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2
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Lysosomal multienzyme complex: pros and cons of working together. Cell Mol Life Sci 2013; 71:2017-32. [PMID: 24337808 DOI: 10.1007/s00018-013-1538-3] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 11/29/2013] [Accepted: 12/02/2013] [Indexed: 12/31/2022]
Abstract
The ubiquitous distribution of lysosomes and their heterogeneous protein composition reflects the versatility of these organelles in maintaining cell homeostasis and their importance in tissue differentiation and remodeling. In lysosomes, the degradation of complex, macromolecular substrates requires the synergistic action of multiple hydrolases that usually work in a stepwise fashion. This catalytic machinery explains the existence of lysosomal enzyme complexes that can be dynamically assembled and disassembled to efficiently and quickly adapt to the pool of substrates to be processed or degraded, adding extra tiers to the regulation of the individual protein components. An example of such a complex is the one composed of three hydrolases that are ubiquitously but differentially expressed: the serine carboxypeptidase, protective protein/cathepsin A (PPCA), the sialidase, neuraminidase-1 (NEU1), and the glycosidase β-galactosidase (β-GAL). Next to this 'core' complex, the existence of sub-complexes, which may contain additional components, and function at the cell surface or extracellularly, suggests as yet unexplored functions of these enzymes. Here we review how studies of basic biological processes in the mouse models of three lysosomal storage disorders, galactosialidosis, sialidosis, and GM1-gangliosidosis, revealed new and unexpected roles for the three respective affected enzymes, Ppca, Neu1, and β-Gal, that go beyond their canonical degradative activities. These findings have broadened our perspective on their functions and may pave the way for the development of new therapies for these lysosomal storage disorders.
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3
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Amidate prodrugs of 9-[2-(phosphonomethoxy)ethyl]adenine as inhibitors of adenylate cyclase toxin from Bordetella pertussis. Antimicrob Agents Chemother 2013; 58:664-71. [PMID: 24145524 DOI: 10.1128/aac.01685-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Adenylate cyclase toxin (ACT) is the key virulence factor of Bordetella pertussis that facilitates its invasion into the mammalian body. 9-[2-(Phosphonomethoxy)ethyl]adenine diphosphate (PMEApp), the active metabolite of the antiviral drug bis(POM)PMEA (adefovir dipivoxil), has been shown to inhibit ACT. The objective of this study was to evaluate six novel amidate prodrugs of PMEA, both phenyloxy phosphonamidates and phosphonodiamidates, for their ability to inhibit ACT activity in the J774A.1 macrophage cell line. The two phenyloxy phosphonamidate prodrugs exhibited greater inhibitory activity (50% inhibitory concentration [IC50] = 22 and 46 nM) than the phosphonodiamidates (IC50 = 84 to 3,960 nM). The inhibitory activity of the prodrugs correlated with their lipophilicity and the degree of their hydrolysis into free PMEA in J774A.1 cells. Although the prodrugs did not inhibit ACT as effectively as bis(POM)PMEA (IC50 = 6 nM), they were significantly less cytotoxic. Moreover, they all reduced apoptotic effects of ACT and prevented an ACT-induced elevation of intracellular [Ca(2+)]i. The amidate prodrugs were less susceptible to degradation in Caco-2 cells compared to bis(POM)PMEA, while they exerted good transepithelial permeability in this assay. As a consequence, a large amount of intact amidate prodrug is expected to be available to target macrophages in vivo. This feature makes nontoxic amidate prodrugs attractive candidates for further investigation as novel antimicrobial agents.
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4
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Babusis D, Phan TK, Lee WA, Watkins WJ, Ray AS. Mechanism for Effective Lymphoid Cell and Tissue Loading Following Oral Administration of Nucleotide Prodrug GS-7340. Mol Pharm 2012; 10:459-66. [DOI: 10.1021/mp3002045] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Darius Babusis
- Gilead Sciences, Inc.,
Foster City, California 94404, United States
| | - Truc K. Phan
- Gilead Sciences, Inc.,
Foster City, California 94404, United States
| | - William A. Lee
- Gilead Sciences, Inc.,
Foster City, California 94404, United States
| | | | - Adrian S. Ray
- Gilead Sciences, Inc.,
Foster City, California 94404, United States
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Kreutzer R, Kreutzer M, Sewell AC, Techangamsuwan S, Leeb T, Baumgärtner W. Impact of beta-galactosidase mutations on the expression of the canine lysosomal multienzyme complex. Biochim Biophys Acta Mol Basis Dis 2009; 1792:982-7. [PMID: 19607915 DOI: 10.1016/j.bbadis.2009.07.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 07/02/2009] [Accepted: 07/06/2009] [Indexed: 01/09/2023]
Abstract
beta-galactosidase (GLB1) forms a functional lysosomal multienzyme complex with lysosomal protective protein (PPCA) and neuraminidase 1 (NEU1) which is important for its intracellular processing and activity. Mutations in the beta-galactosidase gene cause the lysosomal storage disease G(M1)-gangliosidosis. In order to identify additional molecular changes associated with the presence of beta-galactosidase mutations, the expression of canine lysosomal multienzyme complex components in GLB1(+/+), GLB1(+/-) and GLB1(-/-) fibroblasts was investigated by quantitative RT-PCR, Western blot and enzymatic assays. Quantitative RT-PCR revealed differential regulation of total beta-galactosidase, beta-galactosidase variants and protective protein for beta-galactosidase gene (PPGB) in GLB1(+/-) and GLB1(-/-) compared to GLB1(+/+) fibroblasts. Furthermore, it was shown that PPGB levels gradually increased with the number of mutant beta-galactosidase alleles while no change in the NEU1 expression was observed. This is the first study that simultaneously examine the effect of GLB1(+/+), GLB1(+/-) and GLB1(-/-) genotypes on the expression of lysosomal multienzyme complex components. The findings reveal a possible adaptive process in GLB1 homozygous mutant and heterozygous individuals that could facilitate the design of efficient therapeutic strategies.
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Affiliation(s)
- Robert Kreutzer
- Department of Pathology, University of Veterinary Medicine, Hannover, Bünteweg 17, D-30559, Hannover, Germany.
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6
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Kidney growth during catabolic illness: what it does not destroy makes it grow stronger. J Ren Nutr 2007; 17:167-72. [PMID: 17462548 DOI: 10.1053/j.jrn.2007.01.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Indexed: 12/19/2022] Open
Abstract
The kidney undergoes hypertrophy under conditions that paradoxically cause a loss of lean body mass, such as diabetes, acidosis, and chronic kidney disease. What unique mechanisms account for kidney growth during negative nitrogen balance? One adaptation is that renal tubular cells substantially decrease protein breakdown during kidney cell growth. In this review, we discuss how acidosis and diabetes reduce protein breakdown within the kidney and the intracellular signaling pathways that may regulate protein metabolism. Our results suggest that in cell culture models and in acute diabetes, kidney cells specifically reduce protein breakdown by the lysosomal pathway of chaperone-mediated autophagy. This differs from the activation of proteolysis by the ubiquitin-proteasome system in muscle in acute diabetes and uremia. A shared signaling pathway regulates protein breakdown in both kidney and skeletal muscle, namely, phosphatidylinositol-3 kinase signaling. Diabetes mellitus activates signaling through this pathway in the kidney while down-regulating it in skeletal muscle. We conclude that similar signaling pathways may regulate distinct proteolytic pathways in different tissues.
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Lee THD, Streb JW, Georger MA, Miano JM. Tissue expression of the novel serine carboxypeptidase Scpep1. J Histochem Cytochem 2006; 54:701-11. [PMID: 16461364 DOI: 10.1369/jhc.5a6894.2006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We previously identified a novel gene designated retinoid-inducible serine carboxypeptidase (RISC or Scpep1). Here we characterize a polyclonal antibody raised to Scpep1 and assess its localization in mouse cells and tissues. Western blot analysis revealed an immunospecific approximately 35-kDa protein corresponding to endogenous Scpep1. This protein is smaller than the predicted approximately 51-kDa, suggesting that Scpep1 is proteolytically cleaved to a mature enzyme. Immunohistochemical studies demonstrate Scpep1 expression in embryonic heart and vasculature as well as in adult aortic smooth muscle cells and endothelial cells. Scpep1 displays a broad expression pattern in adult tissues with detectable levels in epithelia of digestive tract and urinary bladder, islet of Langerhans, type II alveolar cells and macrophages of lung, macrophage-like cells of lymph nodes and spleen, Leydig cells of testis, and nerve fibers in brain and ganglia. Consistent with previous mRNA studies in kidney, Scpep1 protein is restricted to proximal convoluted tubular epithelium (PCT). Immunoelectron microscopy shows enriched Scpep1 within lysosomes of the PCT, and immunofluorescence microscopy colocalizes Scpep1 with lysosomal-associated membrane protein-2. These results suggest that Scpep1 is a widely distributed lysosomal protease requiring proteolytic cleavage for activity. The highly specific Scpep1 antibody characterized herein provides a necessary reagent for elucidating Scpep1 function.
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Affiliation(s)
- Ting-Hein D Lee
- Cardiovascular Research Institute, University of Rochester School of Medicine, 601 Elmwood Avenue, Box 679, Rochester, NY 14642, USA
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8
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Tessitore A, del P Martin M, Sano R, Ma Y, Mann L, Ingrassia A, Laywell ED, Steindler DA, Hendershot LM, d'Azzo A. GM1-ganglioside-mediated activation of the unfolded protein response causes neuronal death in a neurodegenerative gangliosidosis. Mol Cell 2004; 15:753-66. [PMID: 15350219 DOI: 10.1016/j.molcel.2004.08.029] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2004] [Revised: 06/25/2004] [Accepted: 07/07/2004] [Indexed: 10/26/2022]
Abstract
GM1-ganglioside (GM1) is a major sialoglycolipid of neuronal membranes that, among other functions, modulates calcium homeostasis. Excessive accumulation of GM1 due to deficiency of lysosomal beta-galactosidase (beta-gal) characterizes the neurodegenerative disease GM1-gangliosidosis, but whether the accumulation of GM1 is directly responsible for CNS pathogenesis was unknown. Here we demonstrate that activation of an unfolded protein response (UPR) associated with the upregulation of BiP and CHOP and the activation of JNK2 and caspase-12 leads to neuronal apoptosis in the mouse model of GM1-gangliosidosis. GM1 loading of wild-type neurospheres recapitulated the phenotype of beta-gal-/- cells and activated this pathway by depleting ER calcium stores, which ultimately culminated in apoptosis. Activation of UPR pathways did not occur in mice double deficient for beta-gal and ganglioside synthase, beta-gal-/-/GalNAcT-/-, which do not accumulate GM1. These findings suggest that the UPR can be induced by accumulation of the sialoglycolipid GM1 and this causes a novel mechanism of neuronal apoptosis.
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Affiliation(s)
- Alessandra Tessitore
- Department of Genetics and Tumor Cell Biology, St. Jude Children's Research Hospital, 332 N. Lauderdale, Memphis, TN 38105, USA
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Korah N, Smith CE, D'Azzo A, Mui J, Hermo L. Characterization of cell- and region-specific abnormalities in the epididymis of cathepsin a deficient mice. Mol Reprod Dev 2003; 66:358-73. [PMID: 14579412 DOI: 10.1002/mrd.10359] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Cathepsin A (PPCA), a lysosomal carboxypeptidase that functions as a protective protein for alpha-neuraminidase and beta-galactosidase in a multi-enzyme complex, has been shown to be expressed in the epithelial cells of the epididymis. In the present study, the epididymis of PPCA-/- mice from 2 to 10 months of age was compared with those of their wild-type counterparts. Major accumulations of pale vacuoles, corresponding to lysosomes, were noted in principal and narrow/apical cells in PPCA-/- mice, and clear cells also appearing highly vacuolated, were grossly enlarged in size. This was especially evident in the caput and corpus regions, where quantitative analyses confirmed that the epithelium of the tubules in these regions was expanding in profile area. In addition, the base of the epithelium in these regions was often greatly vacuolated, corresponding to cells that presented no identifiable features and appeared to be degenerating. Halo cells dispersed at various levels in the epithelium also appeared to be abnormal, accumulating pale lysosomes. Furthermore, numerous macrophages were observed in the intertubular space of the entire duct, presenting a large size and plethora of pale lysosomes. Taken together, the present data indicate major lysosomal abnormalities in the epididymis of PPCA-/- mice in a cell type and region specific manner. In addition, it is suggested that the compromised halo cells, due to PPCA deficiency within their lysosomes, cannot function properly and as a result there is a recruitment of macrophages in the intertubular space.
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Affiliation(s)
- Nadine Korah
- Department of Anatomy and Cell Biology, McGill University, Montreal, Canada
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10
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Korah N, Smith CE, D'Azzo A, El-Alfy M, Hermo L. Increase in macrophages in the testis of cathepsin a deficient mice suggests an important role for these cells in the interstitial space of this tissue. Mol Reprod Dev 2003; 64:302-20. [PMID: 12548663 DOI: 10.1002/mrd.10209] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Cathepsin A (PPCA) is a lysosomal carboxypeptidase that functions as a protective protein for alpha-neuraminidase and beta-galactosidase in a multienzyme complex. In the present study, the testes of PPCA -/- mice from 2 to 10 months of age were compared with those of their wild type counterparts. While germ and Sertoli cells appeared comparable in appearance and distribution, the mean profile area of seminiferous tubules showed a significant decrease between wild type and PPCA -/- mice, suggesting changes to the seminiferous tubules and their contents. In addition, macrophages in the interstitial space (IS) of PPCA -/- mice were large, spherical, and filled with pale lysosomes, unlike those seen in wild type mice, and a quantitative analysis of their frequency per unit area of IS in PPCA -/- mice revealed a significant increase compared to that of wild type mice; this was also the case for their mean profile area. Absence of mitotic figures, cycling cells, or degenerating figures in the IS suggests that the major recruitment of macrophages appears to be from the circulation. In the IS, Leydig cells also showed an accumulation of large pale lysosomes in PPCA -/- mice, and their frequency also increased significantly as compared to wild type mice. In the electron microscope, a close association of Leydig cell microvilli with the surface of macrophages was pronounced in PPCA -/- mice. Since macrophages and Leydig cells interact by secreting various factors between each other, and considering the fact that Leydig cells show an accumulation of large pale lysosomes in PPCA -/- mice, it is suggested that macrophages accumulate as a result of abnormalities occurring in Leydig cells. Taken together, the data on increase in frequency of macrophages suggests important functions for these cells in both wild type and PPCA -/- mice.
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Affiliation(s)
- Nadine Korah
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
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11
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Sun Y, Witte DP, Jin P, Grabowski GA. Analyses of temporal regulatory elements of the prosaposin gene in transgenic mice. Biochem J 2003; 370:557-66. [PMID: 12467496 PMCID: PMC1223203 DOI: 10.1042/bj20021120] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2002] [Revised: 11/19/2002] [Accepted: 12/06/2002] [Indexed: 11/17/2022]
Abstract
The expression of prosaposin is temporally and spatially regulated at transcriptional and post-translational levels. Transgenic mice with various 5'-flanking deletions of the prosaposin promoter fused to luciferase (LUC) reporters were used to define its temporal regulatory region. LUC expression in the transgenic mice carrying constructs with 234 bp (234LUC), 310 bp (310LUC) or 2400 bp (2400LUC) of the 5'-flanking region was analysed in the central nervous system and eye throughout development. For 310LUC and 2400LUC, low-level LUC activity was maintained until embryonal day 18 in brain, eye and spinal cord. The peak level of LUC activity was at birth, with return to a plateau (1/3 of peak) throughout adulthood. Deletion of the region that included the retinoic acid-receptor-related orphan receptor (ROR alpha)-binding site and sequence-specific transcription factor (Sp1) cluster sites (44-310 bp) suppressed the peak of activity. By comparison, the peak level for 234LUC was shifted 2 weeks into neonatal life in the brain, but not in the eye, and no peak of activity was observed in the spinal cord. The endogenous prosaposin mRNA in eye, spinal cord and cerebellum had low-level expression before birth and continued to increase into adulthood. In cerebrum, the endogenous mRNA showed similar expression profile to constructs 310LUC, 2400LUC and 234LUC, with the peak expression at 1 week and a decreased level in adult. In the brain of the newborn, 2400LUC was highly expressed in the trigeminal ganglion and brain stem regions when compared with the generalized expression pattern for endogenous prosaposin mRNA. These results suggest that the modifiers (ROR alpha- and Sp1-binding sites) residing within 310 bp of the 5'-flanking region mediate developmental regulation in the central nervous system and eye. Additional regulatory elements outside the 5' region of the 2400 bp promoter fragment appear to be essential for the physiological control of the prosaposin locus.
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Affiliation(s)
- Ying Sun
- The Division and Program in Human Genetics, Children's Hospital Medical Center, 3333 Burnet Avenue, PAV 3-52, Cincinnati, OH 45229-3039, USA
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12
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Cuervo AM, Mann L, Bonten EJ, d’Azzo A, Dice J. Cathepsin A regulates chaperone-mediated autophagy through cleavage of the lysosomal receptor. EMBO J 2003; 22:47-59. [PMID: 12505983 PMCID: PMC140041 DOI: 10.1093/emboj/cdg002] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2002] [Revised: 10/04/2002] [Accepted: 10/31/2002] [Indexed: 11/13/2022] Open
Abstract
Protective protein/cathepsin A (PPCA) has a serine carboxypeptidase activity of unknown physiological function. We now demonstrate that this protease activity triggers the degradation of the lysosome-associated membrane protein type 2a (lamp2a), a receptor for chaperone-mediated autophagy (CMA). Degradation of lamp2a is important because its level in the lysosomal membrane is a rate-limiting step of CMA. Cells defective in PPCA show reduced rates of lamp2a degradation, higher levels of lamp2a and higher rates of CMA. Restoration of PPCA protease activity increases rates of lamp2a degradation, reduces levels of lysosomal lamp2a and reduces rates of CMA. PPCA associates with lamp2a on the lysosomal membrane and cleaves lamp2a near the boundary between the luminal and transmembrane domains. In addition to the well-studied role of PPCA in targeting and protecting two lysosomal glycosidases, we have defined a role for the proteolytic activity of this multifunctional protein.
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Affiliation(s)
- Ana Maria Cuervo
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461,
Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105 and Department of Physiology, Tufts University School of Medicine, Boston, MA 02111, USA Corresponding author e-mail:
| | - Linda Mann
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461,
Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105 and Department of Physiology, Tufts University School of Medicine, Boston, MA 02111, USA Corresponding author e-mail:
| | - Erik J. Bonten
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461,
Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105 and Department of Physiology, Tufts University School of Medicine, Boston, MA 02111, USA Corresponding author e-mail:
| | - Alessandra d’Azzo
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461,
Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105 and Department of Physiology, Tufts University School of Medicine, Boston, MA 02111, USA Corresponding author e-mail:
| | - J.Fred Dice
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461,
Department of Genetics, St Jude Children’s Research Hospital, Memphis, TN 38105 and Department of Physiology, Tufts University School of Medicine, Boston, MA 02111, USA Corresponding author e-mail:
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Leimig T, Mann L, Martin MDP, Bonten E, Persons D, Knowles J, Allay JA, Cunningham J, Nienhuis AW, Smeyne R, d'Azzo A. Functional amelioration of murine galactosialidosis by genetically modified bone marrow hematopoietic progenitor cells. Blood 2002; 99:3169-78. [PMID: 11964280 DOI: 10.1182/blood.v99.9.3169] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Protective protein/cathepsin A (PPCA), a lysosomal carboxypeptidase, is deficient in the neurodegenerative lysosomal disorder galactosialidosis (GS). PPCA(-/-) mice display a disease course similar to that of severe human GS, resulting in nephropathy, ataxia, and premature death. Bone marrow transplantation (BMT) in mutant animals using transgenic BM overexpressing the corrective enzyme in either erythroid cells or monocytes/macrophages has proven effective for the improvement of the phenotype, and encouraged the use of genetically modified BM cells for ex vivo gene therapy of GS. Here, we established stable donor hematopoiesis in PPCA(-/-) mice that received hematopoietic progenitors transduced with a murine stem cell virus (MSCV)-based, bicistronic retroviral vector overexpressing PPCA and the green fluorescent protein (GFP) marker. We observed complete correction of the disease phenotype in the systemic organs up to 10 months after transplantation. PPCA(+) BM-derived cells were detected in all tissues, with the highest expression in liver, spleen, BM, thymus, and lung. In addition, a lysosomal immunostaining was seen in nonhematopoietic cells, indicating efficient uptake of the corrective protein by these cells and cross-correction. Expression in the brain occurred throughout the parenchyma but was mainly localized on perivascular areas. However, PPCA expression in the central nervous system was apparently sufficient to delay the onset of Purkinje cell degeneration and to correct the ataxia. The long-term expression and internalization of the PPCA by cells of systemic organs and the clear improvement of the neurologic phenotype support the use of this approach for the treatment of GS in humans. (Blood. 2002;99:3169-3178)
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Affiliation(s)
- Thasia Leimig
- St Jude Children's Research Hospital, Memphis, TN 38105, USA
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14
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Chen J, Streb JW, Maltby KM, Kitchen CM, Miano JM. Cloning of a novel retinoid-inducible serine carboxypeptidase from vascular smooth muscle cells. J Biol Chem 2001; 276:34175-81. [PMID: 11447226 DOI: 10.1074/jbc.m104162200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Retinoids block smooth muscle cell (SMC) proliferation and attenuate neointimal formation after vascular injury, presumably through retinoid receptor-mediated changes in gene expression. To identify target genes in SMC whose encoded proteins could contribute to such favorable biological effects, we performed a subtractive screen for retinoid-inducible genes in cultured SMC. Here, we report on the cloning and initial characterization of a novel retinoid-inducible serine carboxypeptidase (RISC). Expression of RISC is low in cultured SMC but progressively increases over a 5-day time-course treatment with all-trans-retinoic acid. A near full-length rat RISC cDNA was cloned and found to have a 452-amino acid open reading frame containing an amino-terminal signal sequence, followed by several conserved domains comprising the catalytic triad common to members of the serine carboxypeptidase family. In vitro transcription and translation experiments showed that the rat RISC cDNA generates an approximately 51-kDa protein. Confocal immunofluorescence microscopy of COS-7 cells transiently transfected with a RISC-His tag plasmid revealed cytosolic localization of the fusion protein. Western blotting studies using conditioned medium from transfected COS-7 cells suggest that RISC is a secreted protein. Tissue Northern blotting studies demonstrated robust expression of RISC in rat aorta, bladder, and kidney with much lower levels in all other tissues analyzed; high level RISC expression was also observed in human kidney. In situ hybridization verified the localization of RISC to medial SMC of the adult rat aorta. Interestingly, expression in kidney was restricted to proximal convoluted tubules; little or no expression was observed in glomerular cells, distal convoluted and collecting tubules, or medullary cells. Radiation hybrid mapping studies placed the rat RISC locus on chromosome 10q. These studies reveal a novel retinoid-inducible protease whose activity may be involved in vascular wall and kidney homeostasis.
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MESH Headings
- Amino Acid Sequence
- Animals
- Aorta/metabolism
- Base Sequence
- Blotting, Northern
- Blotting, Western
- COS Cells
- Carboxy-Lyases/chemistry
- Carboxy-Lyases/genetics
- Carboxypeptidases/biosynthesis
- Carboxypeptidases/chemistry
- Carboxypeptidases/genetics
- Cells, Cultured
- Chromosome Mapping
- Cloning, Molecular
- DNA, Complementary/metabolism
- In Situ Hybridization
- Kidney/metabolism
- Male
- Microscopy, Confocal
- Microscopy, Fluorescence
- Molecular Sequence Data
- Muscle, Smooth, Vascular/metabolism
- Nucleic Acid Hybridization
- Open Reading Frames
- Phenotype
- Plasmids/metabolism
- Protein Biosynthesis
- RNA, Messenger/metabolism
- Radiation Hybrid Mapping
- Rats
- Rats, Sprague-Dawley
- Recombinant Fusion Proteins/metabolism
- Sequence Homology, Amino Acid
- Time Factors
- Tissue Distribution
- Transcription, Genetic
- Transfection
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Affiliation(s)
- J Chen
- Center for Cardiovascular Research, University of Rochester Medical Center, Rochester, New York 14642, USA
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15
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Liu H, Rhodes M, Wiest DL, Vignali DA. On the dynamics of TCR:CD3 complex cell surface expression and downmodulation. Immunity 2000; 13:665-75. [PMID: 11114379 DOI: 10.1016/s1074-7613(00)00066-2] [Citation(s) in RCA: 283] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
TCR downmodulation following ligation by MHC:peptide complexes is considered to be a pivotal event in T cell activation. Here, we analyzed the dynamics of TCR:CD3 cell surface expression on resting and antigen-activated T cells. We show that the TCR:CD3 complex is very stable and is rapidly internalized and recycled in resting T cells. Surprisingly, the internalization rate is not increased following TCR ligation by MHC:peptide complexes, despite significant TCR downmodulation, suggesting that constitutive internalization rather than ligation-induced downmodulation serves as the force that drives serial ligation. Furthermore, TCR downmodulation is mediated by the intracellular retention of ligated complexes and degradation by lysosomes and proteasomes. Thus, our data demonstrate that ligation induces TCR downmodulation by preventing recycling rather than inducing internalization.
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Affiliation(s)
- H Liu
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38101, USA
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Luedtke CC, Andonian S, Igdoura S, Hermo L. Cathepsin A is expressed in a cell- and region-specific manner in the testis and epididymis and is not regulated by testicular or pituitary factors. J Histochem Cytochem 2000; 48:1131-46. [PMID: 10898806 DOI: 10.1177/002215540004800810] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The epithelial cells of the testis are involved in the production, differentiation, and sustenance of sperm, and those of the epididymis play a major role in sperm maturation, protection, and storage. These tissues express various proteins that respond differently to androgens. Cathepsin A is a multifunctional lysosomal carboxypeptidase that also functions as a protective and an activator protein for neuraminidase and beta-galactosidase. In this study, cathepsin A was immunolocalized by light and electron microscopy using a polyclonal affinity-purified antibody on the testis and epididymis of normal, orchidectomized with or without testosterone supplementation, efferent duct-ligated, and hypophysectomized adult rats. In normal rats, cathepsin A expression was noted in lysosomes of Sertoli and Leydig cells but not in germ cells of the testis, as well as nonciliated cells of the efferent ducts. In the epididymis, a cell- and region-specific distribution of cathepsin A was noted. In experimentally treated animals, no changes were noted in the expression of cathepsin A. Immunolabeling of tissues examined at the electron microscopic level revealed that lysosomes were reactive. These data indicate cell- and region-specific expression of cathepsin A in cells of the testis and epididymis and also indicate that cathepsin A expression is not regulated by testicular or pituitary factors.
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Affiliation(s)
- C C Luedtke
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
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Hahn CN, del Pilar Martin M, Zhou XY, Mann LW, d'Azzo A. Correction of murine galactosialidosis by bone marrow-derived macrophages overexpressing human protective protein/cathepsin A under control of the colony-stimulating factor-1 receptor promoter. Proc Natl Acad Sci U S A 1998; 95:14880-5. [PMID: 9843984 PMCID: PMC24544 DOI: 10.1073/pnas.95.25.14880] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/1998] [Indexed: 11/18/2022] Open
Abstract
Galactosialidosis (GS) is a human neurodegenerative disease caused by a deficiency of lysosomal protective protein/cathepsin A (PPCA). The GS mouse model resembles the severe human condition, resulting in nephropathy, ataxia, and premature death. To rescue the disease phenotype, GS mice were transplanted with bone marrow from transgenic mice overexpressing human PPCA specifically in monocytes/macrophages under the control of the colony stimulating factor-1 receptor promoter. Transgenic macrophages infiltrated and resided in all organs and expressed PPCA at high levels. Correction occurred in hematopoietic tissues and nonhematopoietic organs, including the central nervous system. PPCA-expressing perivascular and leptomeningeal macrophages were detected throughout the brain of recipient mice, although some neuronal cells, such as Purkinje cells, continued to show storage and died. GS mice crossed into the transgenic background reflected the outcome of bone marrow-transplanted mice, but the course of neuronal degeneration was delayed in this model. These studies present definite evidence that macrophages alone can provide a source of corrective enzyme for visceral organs and may be beneficial for neuronal correction if expression levels are sufficient.
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Affiliation(s)
- C N Hahn
- Department of Genetics, St. Jude Children's Research Hospital, 332 North Lauderdale, Memphis, TN 38105, USA
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