1
|
Gal J, Vary C, Gartner CA, Jicha GA, Abner EL, Ortega YS, Choucair I, Wilcock DM, Nelson RS, Nelson PT. Exploratory Mass Spectrometry of Cerebrospinal Fluid from Persons with Autopsy-Confirmed LATE-NC. J Mol Neurosci 2024; 74:65. [PMID: 38987361 DOI: 10.1007/s12031-024-02239-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 06/25/2024] [Indexed: 07/12/2024]
Abstract
Common neuropathologies associated with dementia include Alzheimer's disease neuropathologic change (ADNC) and limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC). Biofluid proteomics provides a window into the pathobiology of dementia and the information from biofluid tests may help guide clinical management. Participants (n = 29) had been autopsied and had antemortem CSF draws in a longitudinal cohort of older adults at the University of Kentucky AD Research Center. Cases were designated as LATE-NC + if they had LATE-NC stage > 1 (n = 9); the remaining 20 cases were designated LATE-NC-. This convenience sample of CSF specimens was analyzed in two separate processes: From one group, aliquots were depleted of highly abundant proteins using affinity spin columns. Tryptic digests of sample proteins were subjected to liquid chromatographic separation and mass spectrometry. Relative quantification was performed using Sciex software. Peptides referent to a total of 949 proteins were identified in the samples depleted of abundant proteins, and 820 different proteins were identified in the non-depleted samples. When the Bonferroni/false-discovery statistical correction was applied to account for having made multiple comparison tests, only 4 proteins showed differential expression (LATE-NC + vs LATE-NC-) in the non-depleted samples (RBP4, MIF, IGHG3, and ITM2B). Post hoc western blots confirmed that RBP4 expression was higher in the LATE-NC + cases at the group level. In summary, an exploratory assessment of proteomes of autopsy-confirmed LATE-NC and non-LATE-NC CSF did not demonstrate a clear-cut proteomic fingerprint that distinguished the two groups. There was, however, an increase in RBP4 protein levels in CSF from LATE-NC cases.
Collapse
Affiliation(s)
- Jozsef Gal
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY, USA
- Department of Neuroscience, University of Kentucky, Lexington, KY, USA
| | - Calvin Vary
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, USA
| | - Carlos A Gartner
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, USA
| | - Gregory A Jicha
- Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, USA
- Department of Neurology, University of Kentucky, Lexington, KY, USA
| | - Erin L Abner
- Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, USA
- School of Public Health, University of Kentucky, Lexington, KY, USA
| | - Yulica S Ortega
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, USA
| | - Ibrahim Choucair
- Department of Pathology and Laboratory Medicine, University of Kentucky, Rm 575 Todd Building, Lexington, KY, 40536, USA
| | - Donna M Wilcock
- Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, USA
- University of Indiana, Indianapolis, IN, USA
| | | | - Peter T Nelson
- Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, USA.
- Department of Pathology and Laboratory Medicine, University of Kentucky, Rm 575 Todd Building, Lexington, KY, 40536, USA.
| |
Collapse
|
2
|
Gal J, Vary C, Gartner CA, Jicha GA, Abner EL, Ortega YS, Choucair I, Wilcock DM, Nelson R, Nelson P. Exploratory mass spectrometry of cerebrospinal fluid from persons with autopsy-confirmed LATE-NC. RESEARCH SQUARE 2023:rs.3.rs-3252238. [PMID: 37674727 PMCID: PMC10479397 DOI: 10.21203/rs.3.rs-3252238/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Background Common neuropathologies associated with dementia include Alzheimer's disease neuropathologic change (ADNC) and limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC). Biofluid proteomics provides a window into the pathobiology of dementia and the information from biofluid tests may help guide clinical management. Methods Participants were recruited from a longitudinal cohort of older adults at the University of Kentucky AD Research Center. A convenience sample of clinically obtained lumbar puncture cerebrospinal fluid (CSF) samples was analyzed from 29 older adults that had autopsy confirmation of the presence or absence of LATE-NC. Nine of the participants had autopsy-confirmed LATE-NC. Antemortem CSF specimens were analyzed in two separate processes: From one group, aliquots were depleted of highly abundant proteins using affinity spin columns. Tryptic digests of sample proteins were subjected to liquid chromatographic separation and mass spectrometry using an Eksigent Ekspert nanoLC 400 system in line with a Sciex 6600+ mass spectrometer. Protein identification was performed using Protein Pilot (Sciex, ver. 5) software, and relative quantification was performed using the SWATH processing microApp in PeakView and MarkerView software (Sciex), respectively. Following data analyses, additional studies were performed using western blots. Results A total of 830 proteins were identified in the samples depleted of abundant proteins, and 730 proteins were identified in the non-depleted samples. Whereas some dementia-related proteins were detected (Aβ peptide and α-synuclein protein), others were not (TDP-43, TMEM106B, and tau proteins). When the Bonferroni correction was applied to correct for multiple comparisons, only 4 proteins showed differential expression (LATE-NC vs non-LATE-NC) in the nondepleted samples (RBP4, MIF, IGHG3 and ITM2B), whereas none showed statistically different changes in the depleted samples. Post-hoc western blots confirmed that RBP4 expression was higher in the LATE-NC cases at the group level, but there was overlap between the levels of RBP4 in LATE-NC and non-LATE-NC cases. Conclusions An exploratory assessment of CSF proteomes of autopsy-confirmed LATE-NC and non-LATE-NC cases from a community-based cohort failed to demonstrate a clear-cut proteomic fingerprint that distinguished the two groups. There was intriguing increase in RBP4 protein levels in CSF from LATE-NC cases. This may provide clues about pathogenetic mechanisms in LATE-NC.
Collapse
|
3
|
Deconvolution of the MBP-Bri2 Interaction by a Yeast Two Hybrid System and Synergy of the AlphaFold2 and High Ambiguity Driven Protein-Protein Docking. CRYSTALS 2022. [DOI: 10.3390/cryst12020197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Myelin basic protein (MBP) is one of the key proteins in the development of multiple sclerosis (MS). However, very few intracellular MBP partners have been identified up to now. In order to find proteins interacting with MBP in the brain, an expression library from the human brain was screened using a yeast two-hybrid system. Here we showed that MBP interacts with the C-terminal 24-residue peptide of Integral transmembrane protein II associated with familial British and Danish dementia (ITM2B/Bri2 or Bri2). This peptide (Bri23R) was one residue longer than the known Bri23 peptide, which is cleaved from the C-terminus of Bri2 during its maturation in the Golgi and has physiological activity as a modulator of amyloid precursor protein processing. Since the spatial structures for both MBP and Bri2 were not known, we used computational methods of structural biology including an artificial intelligence system AlphaFold2 and high ambiguity driven protein-protein docking (HADDOCK 2.1) to gain a mechanistic explanation of the found protein-protein interaction and elucidate a possible structure of the complex of MBP with Bri23R peptide. As expected, MBP was mostly unstructured, although it has well-defined α-helical regions, while Bri23R forms a stable β-hairpin. Simulation of the interaction between MBP and Bri23R in two different environments, as parts of the two-hybrid system fusion proteins and in the form of single polypeptides, showed that MBP twists around Bri23R. The observed interaction results in the adjustment of the size of the internal space between MBP α-helices to the size of the β-hairpin of Bri23R. Since Bri23 is known to inhibit aggregation of amyloid oligomers, and the association of MBP to the inner leaflet of the membrane bilayer shares features with amyloid fibril formation, Bri23 may serve as a peptide chaperon for MBP, thus participating in myelin membrane assembly.
Collapse
|
4
|
Martins F, Santos I, da Cruz E Silva OAB, Tambaro S, Rebelo S. The role of the integral type II transmembrane protein BRI2 in health and disease. Cell Mol Life Sci 2021; 78:6807-6822. [PMID: 34480585 PMCID: PMC11072861 DOI: 10.1007/s00018-021-03932-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/07/2021] [Accepted: 08/26/2021] [Indexed: 10/20/2022]
Abstract
BRI2 is a type II transmembrane protein ubiquitously expressed whose physiological function remains poorly understood. Although several recent important advances have substantially impacted on our understanding of BRI2 biology and function, providing valuable information for further studies on BRI2. These findings have contributed to a better understanding of BRI2 biology and the underlying signaling pathways involved. In turn, these might provide novel insights with respect to neurodegeneration processes inherent to BRI2-related pathologies, namely Familial British and Danish dementias, Alzheimer's disease, ITM2B-related retinal dystrophy, and multiple sclerosis. In this review, we provided a state-of-the-art outline of BRI2 biology, both in physiological and pathological conditions, and discuss the proposed molecular underlying mechanisms. Overall, the BRI2 knowledge here reviewed is of extreme importance and may contribute to propose BRI2 and/or BRI2 proteolytic fragments as novel therapeutic targets for neurodegenerative diseases, such as Alzheimer's disease.
Collapse
Affiliation(s)
- Filipa Martins
- Neuroscience and Signaling Laboratory, Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, 3810-193, Aveiro, Portugal.
| | - Isabela Santos
- Neuroscience and Signaling Laboratory, Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Odete A B da Cruz E Silva
- Neuroscience and Signaling Laboratory, Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Simone Tambaro
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, 141 83, Huddinge, Sweden.
| | - Sandra Rebelo
- Neuroscience and Signaling Laboratory, Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, 3810-193, Aveiro, Portugal.
| |
Collapse
|
5
|
Martins F, Marafona AM, Pereira CD, Müller T, Loosse C, Kolbe K, da Cruz E Silva OAB, Rebelo S. Identification and characterization of the BRI2 interactome in the brain. Sci Rep 2018; 8:3548. [PMID: 29476059 PMCID: PMC5824958 DOI: 10.1038/s41598-018-21453-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 01/05/2018] [Indexed: 01/16/2023] Open
Abstract
BRI family proteins are ubiquitous type II transmembrane proteins but BRI2 is highly expressed in some neuronal tissues. Possible BRI2 functions include neuronal maturation and differentiation. Protein complexes appear to be important in mediating its functions. Previously described BRI2 interactors include the Alzheimer's amyloid precursor protein and protein phosphatase 1, but clearly the identification of novel interactors provides an important tool to understand the role and function of BRI2. To this end three rat brain regions (cerebellum, hippocampus, and cerebral cortex) were processed by BRI2 immunoprecipitation; co-precipitating proteins were identified by Nano-HPLC-MS/MS. The pool of the brain regions resulted in 511 BRI2 interacting proteins (BRI2 brain interactome) of which 120 were brain specific and 49 involved in neuronal differentiation. Brain region-specific analyses were also carried out for cerebellum, hippocampus, and cerebral cortex. Several novel BRI2 interactors were identified among them DLG4/PSD-95, which is singularly important as it places BRI2 in the postsynaptic compartment. This interaction was validated as well as the interaction with GAP-43 and synaptophysin. In essence, the resulting BRI2 brain interactome, associates this protein with neurite outgrowth and neuronal differentiation, as well as synaptic signalling and plasticity. It follows that further studies should address BRI2 particularly given its relevance to neuropathological conditions.
Collapse
Affiliation(s)
- Filipa Martins
- Neuroscience and Signalling Laboratory, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, Aveiro, Portugal
| | - Ana M Marafona
- Neuroscience and Signalling Laboratory, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, Aveiro, Portugal
| | - Cátia D Pereira
- Neuroscience and Signalling Laboratory, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, Aveiro, Portugal
| | - Thorsten Müller
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e. V., Dortmund, Germany
- Cell Signaling, Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Universitätsstr. 150, 44780, Bochum, Germany
- Institute of Psychiatric Phenomics and Genomics, Clinical Center of the University of Munich, Nussbaumstr. 7, 80336, Munich, Germany
| | - Christina Loosse
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e. V., Dortmund, Germany
| | - Katharina Kolbe
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e. V., Dortmund, Germany
- Cell Signaling, Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Universitätsstr. 150, 44780, Bochum, Germany
- Institute of Psychiatric Phenomics and Genomics, Clinical Center of the University of Munich, Nussbaumstr. 7, 80336, Munich, Germany
| | - Odete A B da Cruz E Silva
- Neuroscience and Signalling Laboratory, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, Aveiro, Portugal
| | - Sandra Rebelo
- Neuroscience and Signalling Laboratory, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, Aveiro, Portugal.
| |
Collapse
|
6
|
Martins F, Serrano JB, Müller T, da Cruz E Silva OAB, Rebelo S. BRI2 Processing and Its Neuritogenic Role Are Modulated by Protein Phosphatase 1 Complexing. J Cell Biochem 2017; 118:2752-2763. [PMID: 28176357 DOI: 10.1002/jcb.25925] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/02/2017] [Indexed: 12/18/2022]
Abstract
BRI2 is a ubiquitously expressed type II transmembrane phosphoprotein. BRI2 undergoes proteolytic processing into secreted fragments and during the maturation process it suffers post-translational modifications. Of particular relevance, BRI2 is a protein phosphatase 1 (PP1) interacting protein, where PP1 is able to dephosphorylate the former. Further, disruption of the BRI2:PP1 complex, using BRI2 PP1 binding motif mutants, leads to increased BRI2 phosphorylation levels. However, the physiological function of BRI2 remains elusive; although findings suggest a role in neurite outgrowth and neuronal differentiation. In the work here presented, BRI2 expression during neuronal development was investigated. This increases during neuronal differentiation and an increase in its proteolytic processing is also evident. To elucidate the importance of BRI2 phosphorylation for both proteolytic processing and neuritogenesis, SH-SY5Y cells were transfected with the BRI2 PP1 binding motif mutant constructs. For the first time, it was possible to show that BRI2 phosphorylation is an important regulatory mechanism for its proteolytic processing and its neuritogenic role. Furthermore, by modulating BRI2 processing using an ADAM10 inhibitor, a dual role for BRI2 in neurite outgrowth is suggested: phosphorylated full-length BRI2 appears to be important for the formation of neuritic processes, and BRI2 NTF promotes neurite elongation. This work significantly contributed to the understanding of the physiological function of BRI2 and its regulation by protein phosphorylation. J. Cell. Biochem. 118: 2752-2763, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Filipa Martins
- Neuroscience and Signalling Laboratory, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, Aveiro 3810-193, Portugal
| | - Joana B Serrano
- Neuroscience and Signalling Laboratory, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, Aveiro 3810-193, Portugal
| | - Thorsten Müller
- Cell Signaling in Neurodegeneration (CSIN), Medical Proteome-Center, Ruhr-University Bochum, Bochum 44801, Germany
| | - Odete A B da Cruz E Silva
- Neuroscience and Signalling Laboratory, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, Aveiro 3810-193, Portugal
| | - Sandra Rebelo
- Neuroscience and Signalling Laboratory, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, Aveiro 3810-193, Portugal
| |
Collapse
|
7
|
Melanosomal formation of PMEL core amyloid is driven by aromatic residues. Sci Rep 2017; 7:44064. [PMID: 28272432 PMCID: PMC5341037 DOI: 10.1038/srep44064] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 02/01/2017] [Indexed: 12/05/2022] Open
Abstract
PMEL is a pigment cell protein that forms physiological amyloid in melanosomes. Many amyloids and/or their oligomeric precursors are toxic, causing or contributing to severe, incurable diseases including Alzheimer’s and prion diseases. Striking similarities in intracellular formation pathways between PMEL and various pathological amyloids including Aβ and PrPSc suggest PMEL is an excellent model system to study endocytic amyloid. Learning how PMEL fibrils assemble without apparent toxicity may help developing novel therapies for amyloid diseases. Here we identify the critical PMEL domain that forms the melanosomal amyloid core (CAF). An unbiased alanine-scanning screen covering the entire region combined with quantitative electron microscopy analysis of the full set of mutants uncovers numerous essential residues. Many of these rely on aromaticity for function suggesting a role for π-stacking in melanosomal amyloid assembly. Various mutants are defective in amyloid nucleation. This extensive data set informs the first structural model of the CAF and provides insights into how the melanosomal amyloid core forms.
Collapse
|
8
|
Martins F, Rebelo S, Santos M, Cotrim CZ, da Cruz e Silva EF, da Cruz e Silva OAB. BRI2 and BRI3 are functionally distinct phosphoproteins. Cell Signal 2015; 28:130-44. [PMID: 26515131 DOI: 10.1016/j.cellsig.2015.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/24/2015] [Indexed: 01/21/2023]
Abstract
Three BRI protein family members have been identified. Among these are BRI3 and BRI2, the latter is associated with Familial Danish and Familial British dementias. 'In silico' sequence analysis identified putative PP1 binding sites in BRI2 and BRI3. This is singularly important, given that protein phosphorylation is a major mechanism regulating intracellular processes. Protein phosphatase 1 (PP1) interacting proteins (PIPs) are fundamental in determining substrate specificity and subcellular localization of this phosphatase. More than 200 PIPs have thus far been reported. Both BRI2 and BRI3 are type II transmembrane glycoproteins relevant in neuronal systems. Using Myc-BRI2 and Myc-BRI3, wild type and PP1 binding mutant constructs, it was possible to show, for the first time, that in fact BRI2 and BRI3 bind PP1. The complexes BRI2:PP1 and BRI3:PP1 were validated in vitro and in vivo. The subcellular distribution of BRI2 and BRI3 is similar; both localize to the perinuclear area and Golgi apparatus in non-neuronal cells. However, in SH-SY5Y cells, BRI2 and BRI3 could also be detected in elongated cellular projections ('processes') and in rat cortical neurons both are broadly distributed throughout the cell body, neuritis and the nucleus. Consistently, co-localization of BRI2 and BRI3 with PP1 was evident. The functional significance of these complexes is apparent given that both BRI proteins are substrates of PP1, thus simultaneously this is the first report of BRI2 and BRI3 as phosphoproteins. Moreover, we show that when BRI2 is phosphorylated a significant increase in neuronal outgrowth and differentiation is evident. Interestingly, the Alzheimer's amyloid precursor protein (APP), forms a trimeric complex composed of PP1 and Fe65, with PP1 having the capacity to dephosphorylate APP at Thr668 residue. The emerging consensus appears to be that PP1 containing complexes are crucial in regulating signaling events underlying neuropathological conditions.
Collapse
Affiliation(s)
- Filipa Martins
- Laboratório de Neurociências e Sinalização Celular, Centro de Biologia Celular, iBiMED, SACS, Universidade de Aveiro, Aveiro, Portugal
| | - Sandra Rebelo
- Laboratório de Neurociências e Sinalização Celular, Centro de Biologia Celular, iBiMED, SACS, Universidade de Aveiro, Aveiro, Portugal.
| | - Mariana Santos
- Laboratório de Neurociências e Sinalização Celular, Centro de Biologia Celular, iBiMED, SACS, Universidade de Aveiro, Aveiro, Portugal
| | - Cândida Zita Cotrim
- Laboratório de Neurociências e Sinalização Celular, Centro de Biologia Celular, iBiMED, SACS, Universidade de Aveiro, Aveiro, Portugal
| | - Edgar F da Cruz e Silva
- Laboratório de Neurociências e Sinalização Celular, Centro de Biologia Celular, iBiMED, SACS, Universidade de Aveiro, Aveiro, Portugal
| | - Odete A B da Cruz e Silva
- Laboratório de Neurociências e Sinalização Celular, Centro de Biologia Celular, iBiMED, SACS, Universidade de Aveiro, Aveiro, Portugal
| |
Collapse
|
9
|
Choi H, Han C, Jin S, Kwon JT, Kim J, Jeong J, Kim J, Ham S, Jeon S, Yoo YJ, Cho C. Reduced Fertility and Altered Epididymal and Sperm Integrity in Mice Lacking ADAM7. Biol Reprod 2015; 93:70. [PMID: 26246218 DOI: 10.1095/biolreprod.115.130252] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/31/2015] [Indexed: 12/15/2022] Open
Abstract
The mammalian epididymis is a highly convoluted tubule that connects the testis to the vas deferens. Its proper functions in sperm transport, storage, and maturation are essential for male reproduction. One of the genes predominantly expressed in the epididymis is ADAM7 (a disintegrin and metalloprotease 7). Previous studies have shown that ADAM7 synthesized in the epididymis is secreted into the epididymal lumen and is then transferred to sperm membranes, where it forms a chaperone complex that is potentially involved in sperm fertility. In this study, we generated and analyzed mice with a targeted disruption in the Adam7 gene. We found that the fertility of male mice was modestly but significantly reduced by knockout of Adam7. Histological analyses revealed that the cell heights of the epithelium were dramatically decreased in the caput of the epididymis of Adam7-null mice, suggesting a requirement for ADAM7 in maintaining the integrity of the epididymal epithelium. We found that sperm from Adam7-null mice exhibit decreased motility, tail deformation, and altered tyrosine phosphorylation, indicating that the absence of ADAM7 leads to abnormal sperm functions and morphology. Western blot analyses revealed reduced levels of integral membrane protein 2B (ITM2B) and ADAM2 in sperm from Adam7-null mice, suggesting a requirement for ADAM7 in normal expression of sperm membrane proteins involved in sperm functions. Collectively, our study demonstrates for the first time that ADAM7 is required for normal fertility and is important for the maintenance of epididymal integrity and for sperm morphology, motility, and membrane proteins.
Collapse
Affiliation(s)
- Heejin Choi
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Cecil Han
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Sora Jin
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Jun Tae Kwon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Jihye Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Juri Jeong
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Jaehwan Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Sera Ham
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Suyeon Jeon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Yung Joon Yoo
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Chunghee Cho
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| |
Collapse
|
10
|
Atypical spindle cell lipoma: a clinicopathologic, immunohistochemical, and molecular study emphasizing its relationship to classical spindle cell lipoma. Virchows Arch 2014; 465:97-108. [PMID: 24659226 DOI: 10.1007/s00428-014-1568-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Revised: 01/22/2014] [Accepted: 03/06/2014] [Indexed: 12/16/2022]
Abstract
We studied a series of spindle cell lipomas arising in atypical sites and showing unusual morphologic features (which we called atypical spindle cell lipoma) to assess if these lesions have the same chromosomal alterations as classical spindle cell lipoma but different from those found in atypical lipomatous tumor/well-differentiated liposarcoma. We investigated alterations of different genes in the 13q14 region and the amplification status of the MDM2 and CDK4 genes at 12q14-15 by multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH) analysis. In the atypical spindle cell lipomas, MLPA revealed deletions in the two nearest flanking genes of RB1 (ITM2B and RCBTB2) and in multiple important exons of RB1. In contrast, in classical spindle cell lipomas, a less complex loss of RB1 exons was found but no deletion of ITM2B and RCBTB2. Moreover, MLPA identified a deletion of the DLEU1 gene, a finding which has not been reported earlier. We propose an immunohistochemical panel for lipomatous tumors which comprises of MDM2, CDK4, p16, Rb, which we have found useful in discriminating between atypical or classical spindle cell lipomas and other adipocytic neoplasms, especially atypical lipomatous tumor/well-differentiated liposarcoma. Our findings strengthen the link between atypical spindle cell lipoma and classical spindle cell lipoma, and differentiate them from atypical lipomatous tumor/well-differentiated liposarcoma.
Collapse
|
11
|
The intramembrane proteases signal Peptide peptidase-like 2a and 2b have distinct functions in vivo. Mol Cell Biol 2014; 34:1398-411. [PMID: 24492962 DOI: 10.1128/mcb.00038-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We reported recently that the presenilin homologue signal peptide peptidase-like 2a (SPPL2a) is essential for B cell development by cleaving the N-terminal fragment (NTF) of the invariant chain (li, CD74). Based on this, we suggested that pharmacological modulation of SPPL2a may represent a novel approach to deplete B cells in autoimmune disorders. With regard to reported overlapping substrate spectra of SPPL2a and its close homologue, SPPL2b, we investigated the role of SPPL2b in CD74 NTF proteolysis and its impact on B and dendritic cell homeostasis. In heterologous expression experiments, SPPL2b was found to cleave CD74 NTF with an efficiency similar to that of SPPL2a. For in vivo analysis, SPPL2b single-deficient and SPPL2a/SPPL2b double-deficient mice were generated and examined for CD74 NTF turnover/accumulation, B cell maturation and functionality, and dendritic cell homeostasis. We demonstrate that in vivo SPPL2b does not exhibit a physiologically relevant contribution to CD74 proteolysis in B and dendritic cells. Furthermore, we reveal that both proteases exhibit divergent subcellular localizations in B cells and different expression profiles in murine tissues. These findings suggest distinct functions of SPPL2a and SPPL2b and, based on a high abundance of SPPL2b in brain, a physiological role of this protease in the central nervous system.
Collapse
|
12
|
Del Campo M, Hoozemans JJM, Dekkers LL, Rozemuller AJ, Korth C, Müller-Schiffmann A, Scheltens P, Blankenstein MA, Jimenez CR, Veerhuis R, Teunissen CE. BRI2-BRICHOS is increased in human amyloid plaques in early stages of Alzheimer's disease. Neurobiol Aging 2014; 35:1596-604. [PMID: 24524963 DOI: 10.1016/j.neurobiolaging.2014.01.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/31/2013] [Accepted: 01/08/2014] [Indexed: 10/25/2022]
Abstract
BRI2 protein binds amyloid precursor protein to halt amyloid-β production and inhibits amyloid-β aggregation via its BRICHOS-domain suggesting a link between BRI2 and Alzheimer's disease (AD). Here, we investigate the possible involvement of BRI2 in human AD pathogenesis. BRI2 containing BRICHOS-domain was increased up to 3-fold in AD hippocampus (p = 0.003, n = 14/group). Immunohistochemistry showed BRI2 deposits associated with amyloid-β plaques in early pathologic stages (Braak-III; Thal-2/3). We observed a decrease in the protein levels of ADAM10 (p = 0.02) and furin (p = 0.066), as well as an increase in SPPL2b (p < 0.0001) in AD hippocampus. Because these enzymes are involved in BRI2 processing, their changes may lead to aberrant processing of BRI2 promoting its deposition and likely affecting BRI2 function. Loss of BRI2 function in AD was supported by the decreased presence of BRI2-amyloid precursor protein complexes in the hippocampus of AD patients compared with control subjects. In conclusion, our data obtained from human samples indicate that in early stages of AD there is an increased deposition of BRI2, which likely leads to impaired BRI2 function thereby influencing AD pathophysiology.
Collapse
Affiliation(s)
- Marta Del Campo
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands; Neurochemistry Laboratory, VU University Medical Center, Amsterdam, the Netherlands; Alzheimer Center, VU University Medical Center, Amsterdam, the Netherlands.
| | - Jeroen J M Hoozemans
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands
| | - Lois-Lee Dekkers
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands; Neurochemistry Laboratory, VU University Medical Center, Amsterdam, the Netherlands
| | | | - Carsten Korth
- Department of Neuropathology, Heinrich Heine University Medical School, Düsseldorf, Germany
| | | | - Philip Scheltens
- Alzheimer Center, VU University Medical Center, Amsterdam, the Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands; Neurochemistry Laboratory, VU University Medical Center, Amsterdam, the Netherlands
| | - Connie R Jimenez
- Department of Medical Oncology and OncoProteomics Laboratory, VU University Medical Center, Amsterdam, the Netherlands
| | - Robert Veerhuis
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands; Neurochemistry Laboratory, VU University Medical Center, Amsterdam, the Netherlands; Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; Department of Psychiatry, VU University Medical Center, Amsterdam, the Netherlands
| | - Charlotte E Teunissen
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands; Neurochemistry Laboratory, VU University Medical Center, Amsterdam, the Netherlands
| |
Collapse
|
13
|
Proteomic characterization of a mouse model of familial Danish dementia. J Biomed Biotechnol 2012; 2012:728178. [PMID: 22619496 PMCID: PMC3350990 DOI: 10.1155/2012/728178] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Accepted: 02/02/2012] [Indexed: 11/18/2022] Open
Abstract
A dominant mutation in the ITM2B/BRI2 gene causes familial Danish dementia (FDD) in humans. To model FDD in animal systems, a knock-in approach was recently implemented in mice expressing a wild-type and mutant allele, which bears the FDD-associated mutation. Since these FDD(KI) mice show behavioural alterations and impaired synaptic function, we characterized their synaptosomal proteome via two-dimensional differential in-gel electrophoresis. After identification by nanoliquid chromatography coupled to electrospray-linear ion trap tandem mass spectrometry, the differentially expressed proteins were classified according to their gene ontology descriptions and their predicted functional interactions. The Dlg4/Psd95 scaffold protein and additional signalling proteins, including protein phosphatases, were revealed by STRING analysis as potential players in the altered synaptic function of FDD(KI) mice. Immunoblotting analysis finally demonstrated the actual downregulation of the synaptosomal scaffold protein Dlg4/Psd95 and of the dual-specificity phosphatase Dusp3 in the synaptosomes of FDD(KI) mice.
Collapse
|
14
|
Differential activation of the ER stress factor XBP1 by oligomeric assemblies. Neurochem Res 2012; 37:1707-17. [PMID: 22528838 PMCID: PMC3387497 DOI: 10.1007/s11064-012-0780-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 03/23/2012] [Accepted: 04/04/2012] [Indexed: 12/25/2022]
Abstract
Several neurodegenerative disorders are characterized by protein misfolding, a phenomenon that results in perturbation of cellular homeostasis. We recently identified the protective activity of the ER stress response factor XBP1 (X-box binding protein 1) against Amyloid-ß1-42 (Aß42) neurotoxicity in cellular and Drosophila models of Alzheimer’s disease. Additionally, subtoxic concentrations of Aß42 soluble aggregates (oligomers) induced accumulation of spliced (active) XBP1 transcripts, supporting the involvement of the ER stress response in Aß42 neurotoxicity. Here, we tested the ability of three additional disease-related amyloidogenic proteins to induce ER stress by analyzing XBP1 activation at the RNA level. Treatment of human SY5Y neuroblastoma cells with homogeneous preparations of α-Synuclein (α-Syn), Prion protein (PrP106–126), and British dementia amyloid peptide (ABri1-34) confirmed the high toxicity of oligomers compared to monomers and fibers. Additionally, α-Syn oligomers, but not monomers or fibers, demonstrated potent induction of XBP1 splicing. On the other hand, PrP106–126 and ABri1-34 did not activate XBP1. These results illustrate the biological complexity of these structurally related assemblies and argue that oligomer toxicity depends on the activation of amyloid-specific cellular responses.
Collapse
|
15
|
Tsachaki M, Serlidaki D, Fetani A, Zarkou V, Rozani I, Ghiso J, Efthimiopoulos S. Glycosylation of BRI2 on asparagine 170 is involved in its trafficking to the cell surface but not in its processing by furin or ADAM10. Glycobiology 2011; 21:1382-8. [PMID: 21752865 DOI: 10.1093/glycob/cwr097] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Two different mutated forms of BRI2 protein are linked with familial British and Danish dementias, which present neuropathological similarities with Alzheimer's disease. BRI2 is a type II transmembrane protein that is trafficked through the secretory pathway to the cell surface and is processed by furin and ADAM10 (a disintegrin and metalloproteinase domain 10) to release secreted fragments of unknown function. Its apparent molecular mass (42-44 kDa) is significantly higher than that predicted by the number and composition of amino acids (30 kDa) suggesting that BRI2 is glycosylated. In support, bioinformatics analysis indicated that BRI2 bears the consensus sequence Asn-Thr-Ser (residues 170-173) and could be N-glycosylated at Asn170. Given that N-glycosylation is considered essential for protein folding, processing and trafficking, we examined whether BRI2 is N-glycosylated. Treatment of HEK293 (human embryonic kidney) cells expressing BRI2 with the N-glycosylation inhibitor tunicamycin or mutation of Asn170 to alanine reduced its molecular mass by ~2 kDa. These data indicate that BRI2 is N-glycosylated at Asn170. To examine the effect of N-glycosylation on BRI2 trafficking at the cell surface, we performed biotinylation and (35)S methionine pulse-chase experiments. These experiments showed that mutation of Asn170 to alanine reduced BRI2 trafficking at the cell surface and its steady state levels at the plasma membrane. Furthermore, we obtained data indicating that this mutation did not affect cleavage of BRI2 by furin or ADAM10. Our results confirm the theoretical predictions that BRI2 is N-glycosylated at Asn170 and show that this post-translational modification is essential for its expression at the cell surface but not for its proteolytic processing.
Collapse
Affiliation(s)
- Maria Tsachaki
- Division of Animal and Human Physiology, Department of Biology, National and Kapodistrian University of Athens, 157 84 Panepistimiopolis, Ilisia, Athens, Greece
| | | | | | | | | | | | | |
Collapse
|
16
|
Han C, Park I, Lee B, Jin S, Choi H, Kwon JT, Kwon YI, Kim DH, Park ZY, Cho C. Identification of heat shock protein 5, calnexin and integral membrane protein 2B as Adam7-interacting membrane proteins in mouse sperm. J Cell Physiol 2011; 226:1186-95. [PMID: 20945367 DOI: 10.1002/jcp.22444] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In mammals, sperm acquire their motility and ability to fertilize eggs in the epididymis. This maturation process involves the acquisition of particular proteins from the epididymis. One such secretory protein specifically expressed in the epididymis is Adam7 (a disintegrin and metalloprotease 7). Previous studies have shown that Adam7 that resides in an intracellular compartment of epididymal cells is transferred to sperm membranes, where its levels are dependent on the expression of Adam2 and Adam3, which have critical roles in fertilization. Here, using a proteomics approach based on mass spectrometry, we identified proteins that interact with Adam7 in sperm membranes. This analysis revealed that Adam7 forms complexes with calnexin (Canx), heat shock protein 5 (Hspa5), and integral membrane protein 2B (Itm2b). Canx and Hspa5 are molecular chaperones, and Itm2b is a type II integral membrane protein implicated in neurodegeneration. The interaction of Adam7 with these proteins was confirmed by immunoprecipitation-Western blot analysis. We found that Adam7 and Itm2b are located in detergent-resistant regions known to be highly correlated with membrane lipid rafts. We further found that the association of Adam7 with Itm2b is remarkably promoted during sperm capacitation owing to a conformational change of Adam7 that occurs in concert with the capacitation process. Thus, our results suggest that Adam7 functions in fertilization through the formation of a chaperone complex and enhanced association with Itm2b during capacitation in sperm.
Collapse
Affiliation(s)
- Cecil Han
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Haruyama N, Hatakeyama J, Moriyama K, Kulkarni AB. Amelogenins: Multi-Functional Enamel Matrix Proteins and Their Binding Partners. J Oral Biosci 2011. [DOI: 10.1016/s1349-0079(11)80009-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
18
|
Harris VK, Diamanduros A, Good P, Zakin E, Chalivendra V, Sadiq SA. Bri2-23 is a potential cerebrospinal fluid biomarker in multiple sclerosis. Neurobiol Dis 2010; 40:331-9. [PMID: 20600910 DOI: 10.1016/j.nbd.2010.06.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 05/04/2010] [Accepted: 06/14/2010] [Indexed: 12/13/2022] Open
Abstract
To identify potential multiple sclerosis (MS)-specific biomarkers, we used a proteomic approach to screen cerebrospinal fluid (CSF) from 40 MS patients and 13 controls. We identified seven proteins (Beta-2-microglobulin, Bri2-23, Fetuin-A, Kallikrein-6, Plasminogen, Ribonuclease-1, and Transferrin) that had significantly altered levels in MS compared to controls. Clinical subgroup analysis revealed that decreased CSF levels of Bri2-23, a peptide cleaved from Bri2, were significantly associated with patients having cerebellar dysfunction and cognition impairment. Furthermore, expression levels of Bri2 were specifically decreased in the cerebellum compared to other areas of same brain in MS but not in controls, suggesting that decreased cerebellar Bri2 expression may play a role in cerebellar dysfunction. The association with cognition impairment is also of interest because Bri2 is linked to the amyloid processing pathway in the brain. CSF levels of Bri2-23 may serve as a biomarker of these functions in MS and merits further investigation.
Collapse
Affiliation(s)
- Violaine K Harris
- Multiple Sclerosis Research Center of New York, New York, NY 10019, USA
| | | | | | | | | | | |
Collapse
|
19
|
The extracellular domain of Bri2 (ITM2B) binds the ABri peptide (1–23) and amyloid β-peptide (Aβ1–40): Implications for Bri2 effects on processing of amyloid precursor protein and Aβ aggregation. Biochem Biophys Res Commun 2010; 393:356-61. [DOI: 10.1016/j.bbrc.2009.12.122] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Accepted: 12/21/2009] [Indexed: 11/17/2022]
|