1
|
Witucki Ł, Borowczyk K, Suszyńska-Zajczyk J, Warzych E, Pawlak P, Jakubowski H. Deletion of the Homocysteine Thiolactone Detoxifying Enzyme Bleomycin Hydrolase, in Mice, Causes Memory and Neurological Deficits and Worsens Alzheimer's Disease-Related Behavioral and Biochemical Traits in the 5xFAD Model of Alzheimer's Disease. J Alzheimers Dis 2023; 95:1735-1755. [PMID: 37718819 PMCID: PMC10578231 DOI: 10.3233/jad-230578] [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] [Accepted: 08/05/2023] [Indexed: 09/19/2023]
Abstract
BACKGROUND Bleomycin hydrolase (BLMH), a homocysteine (Hcy)-thiolactone detoxifying enzyme, is attenuated in Alzheimer's disease (AD) brains. Blmh loss causes astrogliosis in mice while the loss of histone demethylase Phf8, which controls mTOR signaling, causes neuropathy in mice and humans. OBJECTIVE To examine how Blmh gene deletion affects the Phf8/H4K20me1/mTOR/autophagy pathway, amyloid-β (Aβ) accumulation, and cognitive/neuromotor performance in mice. METHODS We generated a new mouse model of AD, the Blmh-/-5xFAD mouse. Behavioral assessments were conducted by cognitive/neuromotor testing. Blmh and Phf8 genes were silenced in mouse neuroblastoma N2a-APPswe cells by RNA interference. mTOR- and autophagy-related proteins, and AβPP were quantified by western blotting and the corresponding mRNAs by RT-qPCR. Aβ was quantified by western blotting (brains) and by confocal microscopy (cells). RESULTS Behavioral testing showed cognitive/neuromotor deficits in Blmh-/- and Blmh-/-5xFAD mice. Phf8 was transcriptionally downregulated in Blmh-/- and Blmh-/-5xFAD brains. H4K20me1, mTOR, phospho-mTOR, and AβPP were upregulated while autophagy markers Becn1, Atg5, and Atg7 were downregulated in Blmh-/- and Blmh-/-5xFAD brains. Aβ was elevated in Blmh-/-5xFAD brains. These biochemical changes were recapitulated in Blmh-silenced N2a-APPswe cells, which also showed increased H4K20me1-mTOR promoter binding and impaired autophagy flux (Lc3-I, Lc3-II, p62). Phf8-silencing or treatments with Hcy-thiolactone or N-Hcy-protein, metabolites elevated in Blmh-/- mice, induced biochemical changes in N2a-APPswe cells like those induced by the Blmh-silencing. However, Phf8-silencing elevated Aβ without affecting AβPP. CONCLUSIONS Our findings show that Blmh interacts with AβPP and the Phf8/H4K20me1/mTOR/autophagy pathway, and that disruption of those interactions causes Aβ accumulation and cognitive/neuromotor deficits.
Collapse
Affiliation(s)
- Łukasz Witucki
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań, Poland
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, New Jersey Medical School, International Center for Public Health, Newark, NJ, USA
| | - Kamila Borowczyk
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, New Jersey Medical School, International Center for Public Health, Newark, NJ, USA
| | - Joanna Suszyńska-Zajczyk
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań, Poland
| | - Ewelina Warzych
- Department of Genetics and Animal Breeding, Poznań University of Life Sciences, Poznań, Poland
| | - Piotr Pawlak
- Department of Genetics and Animal Breeding, Poznań University of Life Sciences, Poznań, Poland
| | - Hieronim Jakubowski
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznań, Poland
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, New Jersey Medical School, International Center for Public Health, Newark, NJ, USA
| |
Collapse
|
2
|
Zheng YZ, Cui J, Wang YL, Huang SJ, Lin EC, Huang SC, Rudolf JD, Yan X, Chang CY. The structure-function relationship of human bleomycin hydrolase: mutation of a cysteine protease into a serine protease. Chembiochem 2022; 23:e202200186. [PMID: 35467071 DOI: 10.1002/cbic.202200186] [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: 04/01/2022] [Revised: 04/24/2022] [Indexed: 11/07/2022]
Abstract
Human bleomycin hydrolase (hBH) catalyzes deamidation of the anticancer drug, bleomycins (BLM). This enzyme is involved in BLM detoxification and drug resistance. Herein, we report the putative BLM-binding site and catalytic mechanism of hBH. The crystal structures and biochemical studies support that hBH cleaves its C-terminal residue without significant preference for the type of amino acids, and therefore can accordingly accommodate the β-aminoalanine amide moiety of BLM for deamidation. Interestingly, hBH is capable of switching from a cysteine protease to a serine protease that is unable to cleave the secondary amide of hBH C-terminus but reacts with the primary amide of BLMs.
Collapse
Affiliation(s)
- Yi-Zhen Zheng
- National Yang Ming Chiao Tung University, Department of Biological Science and Technology, TAIWAN
| | - Jingxuan Cui
- Tianjin University of Traditional Chinese Medicine, State Key Laboratory of Component-Based Chinese Medicine, CHINA
| | | | - Szu-Jo Huang
- National Yang Ming Chiao Tung University, Department of Biological Science and Technology, TAIWAN
| | - En-Chi Lin
- National Yang Ming Chiao Tung University, Department of Biological Science and Technology, TAIWAN
| | - Sheng-Cih Huang
- National Yang Ming Chiao Tung University, Department of Applied Chemistry, TAIWAN
| | - Jeffrey D Rudolf
- University of Florida Department of Chemistry, Department of Chemistry, UNITED STATES
| | - Xiaohui Yan
- Tianjin University of Traditional Chinese Medicine, State Key Laboratory of Component-Based Chinese Medicine, CHINA
| | - Chin-Yuan Chang
- National Yang Ming Chiao Tung University, Department of Biological Science and Technology, No. 75, Boai Street, 300, Hsinchu, TAIWAN
| |
Collapse
|
3
|
Elsheikh SSM, Chimusa ER, Mulder NJ, Crimi A. Relating Global and Local Connectome Changes to Dementia and Targeted Gene Expression in Alzheimer's Disease. Front Hum Neurosci 2022; 15:761424. [PMID: 35002653 PMCID: PMC8734427 DOI: 10.3389/fnhum.2021.761424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/25/2021] [Indexed: 01/01/2023] Open
Abstract
Networks are present in many aspects of our lives, and networks in neuroscience have recently gained much attention leading to novel representations of brain connectivity. The integration of neuroimaging characteristics and genetics data allows a better understanding of the effects of the gene expression on brain structural and functional connections. The current work uses whole-brain tractography in a longitudinal setting, and by measuring the brain structural connectivity changes studies the neurodegeneration of Alzheimer's disease. This is accomplished by examining the effect of targeted genetic risk factors on the most common local and global brain connectivity measures. Furthermore, we examined the extent to which Clinical Dementia Rating relates to brain connections longitudinally, as well as to gene expression. For instance, here we show that the expression of PLAU gene increases the change over time in betweenness centrality related to the fusiform gyrus. We also show that the betweenness centrality metric impact dementia-related changes in distinct brain regions. Our findings provide insights into the complex longitudinal interplay between genetics and brain characteristics and highlight the role of Alzheimer's genetic risk factors in the estimation of regional brain connectivity alterations.
Collapse
Affiliation(s)
- Samar S M Elsheikh
- Pharmacogenetic Research Clinic, Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, ON, Canada.,Computational Biology Division, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Emile R Chimusa
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | | | - Nicola J Mulder
- Computational Biology Division, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Alessandro Crimi
- Computer Vision Group, Sano Centre for Computational Medicine, Kraków, Poland.,Institute for Neuropathology, University Hospital of Zurich, Zurich, Switzerland.,Department of Mathematics, African Institute for Mathematical Sciences, Cape Coast, Ghana
| |
Collapse
|
4
|
Crnovcic I, Gan F, Yang D, Dong LB, Schultz PG, Shen B. Activities of recombinant human bleomycin hydrolase on bleomycins and engineered analogues revealing new opportunities to overcome bleomycin-induced pulmonary toxicity. Bioorg Med Chem Lett 2018; 28:2670-2674. [PMID: 29730026 DOI: 10.1016/j.bmcl.2018.04.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/26/2018] [Accepted: 04/27/2018] [Indexed: 02/08/2023]
Abstract
The bleomycins (BLMs) are widely used in combination therapies for the treatment of various cancers. Dose-dependent and cumulative pulmonary toxicity is the major cause of BLM-associated morbidity, limiting the broad uses of BLMs as anticancer drugs. The organ specificity of BLM-induced toxicity has been correlated with the expression of the hBLMH gene, encoding the human bleomycin hydrolase (hBLMH), which is poorly expressed in the lung. hBLMH hydrolyzes BLMs into the biologically inactive deamido BLMs, thereby protecting organs from BLM-induced toxicity. Here we report (i) expression of hBLMH and production and isolation of recombinant human bleomycin hydrolase (rhBLMH) from E. coli, (ii) structural characterization of deamido BLM A2 and B2 isolated from rhBLMH-catalyzed hydrolysis of BLM A2 and B2, and (iii) kinetic characterization of the rhBLMH-catalyzed hydrolysis of BLM A2 and B2, in comparison with five BLM analogues. rhBLMH from E. coli catalyzes rapid and efficient hydrolysis of all BLMs tested, exhibiting a superior catalytic efficiency for BLM B2. These findings reveal new opportunities to overcome BLM-induced pulmonary toxicity in chemotherapies, potentially by exploring BLM B2 as the preferred congener, engineering designer BLMs with optimized activity for rhBLMH, or co-administrating rhBLMH directly into the lung as a potential protein therapeutic.
Collapse
Affiliation(s)
- Ivana Crnovcic
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, United States
| | - Fei Gan
- California Institute for Biomedical Research, La Jolla, CA 92037, United States
| | - Dong Yang
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, United States
| | - Liao-Bin Dong
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, United States
| | - Peter G Schultz
- California Institute for Biomedical Research, La Jolla, CA 92037, United States; Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Ben Shen
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, United States; Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, United States; Natural Products Library Initiative at The Scripps Research Institute, The Scripps Research Institute, Jupiter, FL 33458, United States.
| |
Collapse
|
5
|
Smach MA, Charfeddine B, Lammouchi T, Othman LB, Letaief A, Nafati S, Dridi H, Bennamou S, Limem K. Analysis of association between bleomycin hydrolase and apolipoprotein E polymorphism in Alzheimer’s disease. Neurol Sci 2010; 31:687-91. [DOI: 10.1007/s10072-010-0234-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Accepted: 01/26/2010] [Indexed: 11/28/2022]
|
6
|
Combarros O, Cortina-Borja M, Smith AD, Lehmann DJ. Epistasis in sporadic Alzheimer's disease. Neurobiol Aging 2009; 30:1333-49. [PMID: 18206267 DOI: 10.1016/j.neurobiolaging.2007.11.027] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 11/30/2007] [Accepted: 11/30/2007] [Indexed: 10/22/2022]
|
7
|
Llorca J, Rodríguez-Rodríguez E, Dierssen-Sotos T, Delgado-Rodríguez M, Berciano J, Combarros O. Meta-analysis of genetic variability in the beta-amyloid production, aggregation and degradation metabolic pathways and the risk of Alzheimer's disease. Acta Neurol Scand 2008; 117:1-14. [PMID: 17854420 DOI: 10.1111/j.1600-0404.2007.00899.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Variants in genes encoding enzymes involved in production, aggregation or degradation of beta-amyloid are potential risk factors for sporadic Alzheimer's disease (AD). METHODS Meta-analyses on AD association with BACE1 exon 5, BACE1 intron 5, FE65 intron 13, CYP46 intron 2, alpha(1)-antichymotrypsine Ala17Thr, bleomycin hydrolase I443V, lectin-like oxidized low-density lipoprotein receptor (OLR1) 3'-UTR (+1071) and (+1073), and very-low-density lipoprotein receptor (VLDLR) 5'-UTR (CGG-repeat) polymorphisms. RESULTS In BACE1 exon 5, genotype CC+CT acts as a protective factor in Apolipoprotein E (ApoE) epsilon 4 carriers [odds ratio (OR) = 0.57; 95% confidence interval (CI): 0.38-0.88], and as a risk factor in ApoE epsilon 4 non-carriers (OR = 1.33; 95% CI: 1.00-1.78). OLR1 3'-UTR (+1073) allele C is associated with increased risk (OR = 1.23; 95% CI: 1.01-1.50). VLDLR 5'-UTR genotype 2 is associated with increased risk (OR = 1.70; 95% CI: 1.09-2.63) in the Asian population and is protective (OR = 0.48; 95% CI: 0.26-0.86) in the non-Asian population. Other studied polymorphisms are not associated with AD. CONCLUSIONS The overall impact on AD risk of the genes for which meta-analyses are now available is rather limited. Additional meta-analyses of other different genes encoding for A beta production, aggregation and degradation mediators might help in determining the risk profile for AD.
Collapse
Affiliation(s)
- J Llorca
- Division of Epidemiology and Computational Biology, University of Cantabria School of Medicine, Santander, Spain.
| | | | | | | | | | | |
Collapse
|
8
|
Nuver J, Lutke Holzik MF, van Zweeden M, Hoekstra HJ, Meijer C, Suurmeijer AJH, Groen HJM, Hofstra RM, Sluiter WJ, Groen H, Sleijfer DT, Gietema JA. Genetic variation in the bleomycin hydrolase gene and bleomycin-induced pulmonary toxicity in germ cell cancer patients. Pharmacogenet Genomics 2005; 15:399-405. [PMID: 15900213 DOI: 10.1097/01213011-200506000-00005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Use of bleomycin as a cytotoxic agent is limited by its pulmonary toxicity. Bleomycin is mainly excreted by the kidneys, but can also be inactivated by bleomycin hydrolase (BMH). An 1450A>G polymorphic site in the BMH gene results in an amino acid substitution in the C-terminal domain of the protein. Deletion of this domain, including the polymorphic site, reduces enzymatic activity. We investigated the relation between the BMH genotype and the risk of bleomycin-induced pneumonitis (BIP). METHODS From male germ cell cancer patients, treated with bleomycin-containing chemotherapy at the University Hospital Groningen, The Netherlands, between 1977 and 2003, data were collected on age, cumulative bleomycin dose, pretreatment creatinine clearance, pulmonary metastases, lung function parameters, and occurrence of BIP. BIP was defined as: death due to BIP, or presence of clinical and/or radiographic signs of BIP during or following treatment. Polymerase chain reaction and restriction fragment length polymorphism were used to determine the BMH genotype. RESULTS BIP developed in 38 (11%) of 340 patients; four of these cases were fatal. BMH genotype distribution did not differ between patients with and those without BIP. Patients with BIP were older and had a lower pretreatment creatinine clearance. Changes in pulmonary function tests were similar in patients with different genotypes. CONCLUSIONS The BMH genotype was not associated with the development of BIP nor with changes in pulmonary function tests. Since renal function is important for bleomycin pharmacokinetics, variations in renal clearance may have obscured significant effects of the BMH genotype.
Collapse
Affiliation(s)
- Janine Nuver
- Department of Medical Oncology, University Medical Center Groningen, Groningen, The Netherlands
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Rocchi A, Pellegrini S, Siciliano G, Murri L. Causative and susceptibility genes for Alzheimer's disease: a review. Brain Res Bull 2003; 61:1-24. [PMID: 12788204 DOI: 10.1016/s0361-9230(03)00067-4] [Citation(s) in RCA: 216] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Alzheimer's disease (AD) is the most common type of dementia in the elderly population. Three genes have been identified as responsible for the rare early-onset familial form of the disease: the amyloid precursor protein (APP) gene, the presenilin 1 (PSEN1) gene and the presenilin 2 (PSEN2) gene. Mutations in these genes, however, account for less than 5% of the total number of AD cases. The remaining 95% of AD patients are mostly sporadic late-onset cases, with a complex aetiology due to interactions between environmental conditions and genetic features of the individual. In this paper, we review the most important genes supposed to be involved in the pathogenesis of AD, known as susceptibility genes, in an attempt to provide a comprehensive picture of what is known about the genetic mechanisms underlying the onset and progression of AD. Hypotheses about the role of each gene in the pathogenic pathway are discussed, taking into account the functions and molecular features, if known, of the coded protein. A major susceptibility gene, the apolipoprotein E (APOE) gene, found to be associated with sporadic late-onset AD cases and the only one, whose role in AD has been confirmed in numerous studies, will be included in a specific chapter. As the results reported by association studies are conflicting, we conclude that a better understanding of the complex aetiology that underlies AD may be achieved likely through a multidisciplinary approach that combines clinical and neurophysiological characterization of AD subtypes and in vivo functional brain imaging studies with molecular investigations of genetic components.
Collapse
Affiliation(s)
- A Rocchi
- Department of Neurosciences, Neurological Clinics, University of Pisa Medical School, Via Roma 67, 56126 Pisa, Italy
| | | | | | | |
Collapse
|
10
|
|
11
|
Abstract
Alzheimer's disease (AD) is a genetically complex disorder associated with multiple genetic defects either mutational or of susceptibility. Current AD genetics does not explain in full the etiopathogenesis of AD, suggesting that environmental factors and/or epigenetic phenomena may also contribute to AD pathology and phenotypic expression of dementia. The genomics of AD is still in its infancy, but is helping us to understand novel aspects of the disease including genetic epidemiology, multifactorial risk factors, pathogenic mechanisms associated with genetic networks and genetically-regulated metabolic cascades. AD genomics is also fostering new strategies in pharmacogenomic research and prevention. Functional genomics, proteomics, pharmacogenomics, high-throughput methods, combinatorial chemistry and modern bioinformatics will greatly contribute to accelerating drug development for AD and other complex disorders. The multifactorial genetic dysfunction in AD includes mutational loci (APP, PS1, PS2) and diverse susceptibility loci (APOE, A2M, AACT, LRP1, IL1A, TNF, ACE, BACE, BCHE, CST3, MTHFR, GSK3B, NOS3) distributed across the human genome, probably converging in common pathogenic mechanisms that lead to premature neuronal death. Genomic associations integrate polygenic matrix models to elucidate the genomic organization of AD in comparison to the control population. Using APOE-related monogenic models it has been demonstrated that the therapeutic response to drugs (e.g., cholinesterase inhibitors, non-cholinergic compounds) in AD is genotype-specific. A multifactorial therapy combining three different drugs yielded positive results during 6-12 months in approximately 60% of the patients. With this therapeutic strategy, APOE-4/4 carriers were the worst responders and patients with the APOE-3/4 genotype were the best responders. Other polymorphic variants (PS1, PS2) also influence the therapeutic response to different drugs in AD patients, suggesting that the final pharmacological outcome is the result of multiple genomic interactions, including AD-related genes and genes associated with drug metabolism, disposition, and elimination. The pharmacogenomics of AD may contribute in the future to optimise drug development and therapeutics, increasing efficacy and safety, and reducing side-effects and unnecessary costs.
Collapse
Affiliation(s)
- Ramón Cacabelos
- From the EuroEspes Biomedical Research Center, Institute for CNS Disorders, Bergondo, La Coruña, Spain.
| |
Collapse
|
12
|
Lefterov IM, Koldamova RP, Lefterova MI, Schwartz DR, Lazo JS. Cysteine 73 in bleomycin hydrolase is critical for amyloid precursor protein processing. Biochem Biophys Res Commun 2001; 283:994-9. [PMID: 11350084 DOI: 10.1006/bbrc.2001.4860] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human bleomycin hydrolase (hBH) is a neutral cysteine protease that may regulate the secretion of soluble amyloid precursor protein (APP) and amyloid beta (A(beta)), which is a major constituent of the Alzheimer's disease-associated amyloid plaques. We have now determined that APP interacts with hBH by using yeast two hybrid methods and in vitro binding studies revealed that APP interacted with a 68 amino acid region that includes the catalytic domain of hBH. Ectopic expression of hBH increased the secretion of A(beta) but not of a second secreted protein, apolipoprotein A-I. Expression of hBH in which the catalytic cysteine 73 was mutated to serine failed to increase A(beta) secretion. These results indicate a critical role for cysteine 73 of hBH in mediating APP processing.
Collapse
Affiliation(s)
- I M Lefterov
- Department of Pharmacology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | | | | | | | | |
Collapse
|
13
|
Nixon RA, Cataldo AM, Mathews PM. The endosomal-lysosomal system of neurons in Alzheimer's disease pathogenesis: a review. Neurochem Res 2000; 25:1161-72. [PMID: 11059790 DOI: 10.1023/a:1007675508413] [Citation(s) in RCA: 257] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A prominent feature of brain pathology in Alzheimer's disease is a robust activation of the neuronal lysosomal system and major cellular pathways converging on the lysosome, namely, endocytosis and autophagy. Recent studies that identify a disturbance of the endocytic pathway as one of the earliest known manifestation of Alzheimer's disease provide insight into how beta-amyloidogenesis might be promoted in sporadic Alzheimer's disease, the most prevalent and least well understood form of the disease. Primary lysosomal dysfunction has historically been linked to neurodegeneration. New data now directly implicate cathepsins as proteases capable of initiating, as well as executing, cell death programs in certain pathologic states. These and other studies support the view that the progressive alterations of lysosomal function observed during aging and Alzheimer's disease contribute importantly to the neurodegenerative process in Alzheimer's disease.
Collapse
Affiliation(s)
- R A Nixon
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, New York 10962, USA.
| | | | | |
Collapse
|
14
|
Lefterov IM, Koldamova RP, Lazo JS. Human bleomycin hydrolase regulates the secretion of amyloid precursor protein. FASEB J 2000; 14:1837-47. [PMID: 10973933 DOI: 10.1096/fj.99-0938com] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Human bleomycin hydrolase (hBH) is a neutral cysteine protease genetically associated with increased risk for Alzheimer disease. We show here that ectopic expression of hBH in 293APPwt and CHOAPPsw cells altered the processing of amyloid precursor protein (APP) and increased significantly the release of its proteolytic fragment, beta amyloid (Abeta). We also found that hBH interacted and colocalized with APP as determined by subcellular fractionation, in vitro binding assay, and confocal immunolocalization. Metabolic labeling and pulse-chase experiments showed that ectopic hBH expression increased secretion of soluble APPalpha/beta products without changing the half-life of cellular APP. We also observed that this increased Abeta secretion was independent of hBH isoforms. Our findings suggest a regulatory role for hBH in APP processing pathways.
Collapse
Affiliation(s)
- I M Lefterov
- Department of Pharmacology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15261, USA
| | | | | |
Collapse
|
15
|
Tandon A, Rogaeva E, Mullan M, St George-Hyslop PH. Molecular genetics of Alzheimer's disease: the role of beta-amyloid and the presenilins. Curr Opin Neurol 2000; 13:377-84. [PMID: 10970053 DOI: 10.1097/00019052-200008000-00003] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease is the most common neurodegenerative disorder of aging, accounting for an estimated two-thirds of all cases of senile dementia. Epidemiologic studies have failed to resolve any single cause of Alzheimer's disease and suggest a complex etiology, with environmental and genetic factors influencing the pathogenesis. Although the majority of cases are sporadic, a small number display familial clustering. Genetic analyses of these pedigrees have identified four genes that are involved in the development of Alzheimer's disease.
Collapse
Affiliation(s)
- A Tandon
- Centre for Research in Neurodegenerative Diseases, Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
16
|
Malherbe P, Faull RL, Richards JG. Regional and cellular distribution of bleomycin hydrolase mRNA in human brain: comparison between Alzheimer's diseased and control brains. Neurosci Lett 2000; 281:37-40. [PMID: 10686410 DOI: 10.1016/s0304-3940(00)00802-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Genetic polymorphism of human bleomycin hydrolase (hBH) has been reported to be associated with the risk of sporadic Alzheimer's disease (AD). The regional and cellular distribution of mRNA encoding hBH in the brain from controls and patients with AD was examined using in situ hybridization. A hybridization signal, in the form of clusters of single cells, was observed in the white matter. Our results indicate a predominantly astrocytic expression of hBH in the investigated human brain regions. Although the signal intensity was generally reduced in AD brains, the large variability among controls rendered this trend statistically insignificant.
Collapse
Affiliation(s)
- P Malherbe
- Pharma Division, Preclinical CNS Research, Building 69/235, F. Hoffmann-La Roche Ltd, CH-4070, Basel, Switzerland
| | | | | |
Collapse
|
17
|
Papassotiropoulos A, Bagli M, Jessen F, Frahnert C, Rao ML, Maier W, Heun R. Confirmation of the association between bleomycin hydrolase genotype and Alzheimer's disease. Mol Psychiatry 2000; 5:213-5. [PMID: 10822352 DOI: 10.1038/sj.mp.4000656] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bleomycin hydrolase (BH), a cysteine protease from the papain superfamily, is considered to be a candidate for the beta-secretase, which is presumably involved in the production of beta-amyloid peptide. The G/G genotype of BH was identified as a significant risk factor for the development of Alzheimer's disease (AD) in subjects not carrying the apolipoprotein E epsilon4 allele (apoE-epsilon4). However, this finding was recently challenged. We studied this polymorphism in a homogenous sample of German AD patients and controls. The over-representation of the G/G genotype in AD patients could be confirmed, however it was more pronounced in apoE-epsilon4 carriers. Additional studies should be undertaken to increase the confidence that the BH polymorphism is associated with AD and to explore the relationship between BH and apoE.
Collapse
Affiliation(s)
- A Papassotiropoulos
- Department of Psychiatry, University of Bonn, Sigmund-Freud-Str 25, 53105 Bonn, Germany
| | | | | | | | | | | | | |
Collapse
|
18
|
Thome J, Gewirtz JC, Sakai N, Zachariou V, Retz-Junginger P, Retz W, Duman RS, Rösler M. Polymorphisms of the human apolipoprotein E promoter and bleomycin hydrolase gene: risk factors for Alzheimer's dementia? Neurosci Lett 1999; 274:37-40. [PMID: 10530514 DOI: 10.1016/s0304-3940(99)00662-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In addition to the apolipoprotein E (ApoE) tri-allele polymorphism, genetic variants of the apolipoprotein E promoter (-491A/T) and the bleomycin hydrolase (BH-PEN) gene have also been proposed as genetic risk factors for Alzheimer's dementia (AD). Since reports about the relevance of these polymorphisms for the pathogenesis of AD have been contradictory, we performed an association study with some modifications. First, the control group in this study was made up of non-demented psychiatric inpatients, rather than healthy subjects. This procedure allows the specificity of the relationship between a given genotype and AD (as opposed to other psychiatric disorders) to be determined. Second, as an alternative to preexisting relatively time consuming techniques, BH-PEN polymorphism was determined using a simplified method based on PCR genotyping. We found a significant linkage disequilibrium between the -491A/T and ApoE polymorphisms. However, no direct association was observed between the -491A/T or BH-PEN polymorphism and AD.
Collapse
Affiliation(s)
- J Thome
- Division of Molecular Psychiatry, Yale University School of Medicine, New Haven, CT 06508, USA.
| | | | | | | | | | | | | | | |
Collapse
|
19
|
|
20
|
Namba Y, Ouchi Y, Asada T, Hattori H, Ueki A, Ikeda K. Lack of association between bleomycin hydrolase gene polymorphism and Alzheimer's disease in Japanese people. Ann Neurol 1999; 46:136-7. [PMID: 10401796 DOI: 10.1002/1531-8249(199907)46:1<136::aid-ana25>3.0.co;2-m] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
21
|
O'Farrell PA, Gonzalez F, Zheng W, Johnston SA, Joshua-Tor L. Crystal structure of human bleomycin hydrolase, a self-compartmentalizing cysteine protease. Structure 1999; 7:619-27. [PMID: 10404591 DOI: 10.1016/s0969-2126(99)80083-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND Bleomycin hydrolase (BH) is a cysteine protease that is found in all tissues in mammals as well as in many other eukaryotes and prokaryotes. Although its conserved cellular function is as yet unknown, human bleomycin hydrolase (hBH) has clinical significance in that it is thought to be the major cause of tumor cell resistance to bleomycin chemotherapy. In addition, it has been reported that an allelic variant of hBH is genetically linked to Alzheimer's disease. RESULTS We have determined the crystal structures of wild-type hBH and of a mutant form of the enzyme. The overall structure is very similar to that of the previously determined yeast homolog, however, there is a striking difference in the charge distribution. The central channel, which has a strong positive electrostatic potential in the yeast protein, is slightly negative in hBH. We have determined that hBH does not have the DNA-binding activity of the yeast protein and that the enzyme is localized to the cytoplasm. CONCLUSIONS The difference in charge distribution between the yeast and human BH enzymes is most likely responsible for the difference in DNA-binding activity. Nevertheless, the C-terminal autoprocessing activity and the role of the C terminus as a determinant for peptidase activity are conserved between the yeast and human forms. The structure of hBH suggests that the putative Alzheimer's disease linked variation does not directly alter the intrinsic peptidase activity. Rather, the position of the mutation suggests that it could affect interactions with another protein, which may modulate peptidase activity through repositioning of the C terminus.
Collapse
Affiliation(s)
- P A O'Farrell
- WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, NY 11724, USA
| | | | | | | | | |
Collapse
|
22
|
Rogaeva EA, Premkumar S, Grubber J, Serneels L, Scott WK, Kawarai T, Song Y, Hill DL, Abou-Donia SM, Martin ER, Vance JJ, Yu G, Orlacchio A, Pei Y, Nishimura M, Supala A, Roberge B, Saunders AM, Roses AD, Schmechel D, Crane-Gatherum A, Sorbi S, Bruni A, Small GW, Conneally PM, Haines JL, Van Leuven F, St George-Hyslop PH, Farrer LA, Pericak-Vance MA. An alpha-2-macroglobulin insertion-deletion polymorphism in Alzheimer disease. Nat Genet 1999; 22:19-22. [PMID: 10319855 DOI: 10.1038/8729] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
23
|
|