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Hatzold J, Nett V, Brantsch S, Zhang JL, Armistead J, Wessendorf H, Stephens R, Humbert PO, Iden S, Hammerschmidt M. Matriptase-dependent epidermal pre-neoplasm in zebrafish embryos caused by a combination of hypotonic stress and epithelial polarity defects. PLoS Genet 2023; 19:e1010873. [PMID: 37566613 PMCID: PMC10446194 DOI: 10.1371/journal.pgen.1010873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 08/23/2023] [Accepted: 07/17/2023] [Indexed: 08/13/2023] Open
Abstract
Aberrantly up-regulated activity of the type II transmembrane protease Matriptase-1 has been associated with the development and progression of a range of epithelial-derived carcinomas, and a variety of signaling pathways can mediate Matriptase-dependent tumorigenic events. During mammalian carcinogenesis, gain of Matriptase activity often results from imbalanced ratios between Matriptase and its cognate transmembrane inhibitor Hai1. Similarly, in zebrafish, unrestrained Matriptase activity due to loss of hai1a results in epidermal pre-neoplasms already during embryogenesis. Here, based on our former findings of a similar tumor-suppressive role for the Na+/K+-pump beta subunit ATP1b1a, we identify epithelial polarity defects and systemic hypotonic stress as another mode of aberrant Matriptase activation in the embryonic zebrafish epidermis in vivo. In this case, however, a different oncogenic pathway is activated which contains PI3K, AKT and NFkB, rather than EGFR and PLD (as in hai1a mutants). Strikingly, epidermal pre-neoplasm is only induced when epithelial polarity defects in keratinocytes (leading to disturbed Matriptase subcellular localization) occur in combination with systemic hypotonic stress (leading to increased proteolytic activity of Matriptase). A similar combinatorial effect of hypotonicity and loss of epithelial polarity was also obtained for the activity levels of Matriptase-1 in human MCF-10A epithelial breast cells. Together, this is in line with the multi-factor concept of carcinogenesis, with the notion that such factors can even branch off from one and the same initiator (here ATP1a1b) and can converge again at the level of one and the same mediator (here Matriptase). In sum, our data point to tonicity and epithelial cell polarity as evolutionarily conserved regulators of Matriptase activity that upon de-regulation can constitute an alternative mode of Matriptase-dependent carcinogenesis in vivo.
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Affiliation(s)
- Julia Hatzold
- Institute of Zoology–Developmental Biology, University of Cologne, Germany
| | - Verena Nett
- Cell and Developmental Biology, Center of Human and Molecular Biology (ZHMB), Saarland University, Faculty of Medicine, Homburg/Saar, Germany
| | - Stephanie Brantsch
- Institute of Zoology–Developmental Biology, University of Cologne, Germany
| | - Jin-Li Zhang
- Institute of Zoology–Developmental Biology, University of Cologne, Germany
| | - Joy Armistead
- Institute of Zoology–Developmental Biology, University of Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University Hospital Cologne, Cologne, Germany
| | - Heike Wessendorf
- Institute of Zoology–Developmental Biology, University of Cologne, Germany
| | - Rebecca Stephens
- Department of Biochemistry & Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Patrick O. Humbert
- Department of Biochemistry & Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Victoria, Australia
- Department of Clinical Pathology, University of Melbourne, Melbourne, Victoria, Australia
| | - Sandra Iden
- Cell and Developmental Biology, Center of Human and Molecular Biology (ZHMB), Saarland University, Faculty of Medicine, Homburg/Saar, Germany
| | - Matthias Hammerschmidt
- Institute of Zoology–Developmental Biology, University of Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University Hospital Cologne, Cologne, Germany
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Lu DD, Huang N, Li SWA, Fang JR, Lai CH, Wang JK, Chan KS, Johnson MD, Lin CY. HAI-1 is required for the novel role of FGFBP1 in maintenance of cell morphology and F-actin rearrangement in human keratinocytes. Hum Cell 2023:10.1007/s13577-023-00906-6. [PMID: 37076641 DOI: 10.1007/s13577-023-00906-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 03/31/2023] [Indexed: 04/21/2023]
Abstract
Formation and maintenance of skin barrier function require tightly controlled membrane-associated proteolysis, in which the integral membrane Kunitz-type serine protease inhibitor, HAI-1, functions as the primary inhibitor of the membrane-associated serine proteases, matriptase and prostasin. Previously, HAI-1 loss in HaCaT human keratinocytes resulted in an expected increase in prostasin proteolysis but a paradoxical decrease in matriptase proteolysis. The paradoxical decrease in shed active matriptase is further investigated in this study with an unexpected discovery of novel functions of fibroblast growth factor-binding protein 1 (FGFBP1), which acts as an extracellular ligand that can rapidly elicit F-actin rearrangement and subsequently affect the morphology of human keratinocytes. This novel growth factor-like function is in stark contrast to the canonical activity of this protein through interactions with FGFs for its pathophysiological functions. This discovery began with the observation that HAI-1 KO HaCaT cells lose the characteristic cobblestone morphology of the parental cells and exhibit aberrant F-actin formation along with altered subcellular targeting of matriptase and HAI-2. The alterations in cell morphology and F-actin status caused by targeted HAI-1 deletion can be restored by treatment with conditioned medium from parental HaCaT cells, in which FGFBP1 was identified by tandem mass spectrometry. Recombinant FGFBP1 down to 1 ng/ml was able to revert the changes caused by HAI-1 loss. Our study reveals a novel function of FGFBP1 in the maintenance of keratinocyte morphology, which depends on HAI-1.
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Affiliation(s)
- Dajun D Lu
- Lombardi Comprehensive Cancer Center, Department of Oncology, W422 Research Building, Georgetown University, W416 Research Building, 3970 Reservoir Road, NW, Washington, DC, 20057, USA
| | - Nanxi Huang
- Lombardi Comprehensive Cancer Center, Department of Oncology, W422 Research Building, Georgetown University, W416 Research Building, 3970 Reservoir Road, NW, Washington, DC, 20057, USA
| | - Sheng-Wen A Li
- School of Medicine National Defense Medical Center, Taipei, 114, Taiwan
| | - Jessica R Fang
- , Winston Churchill High School, Potomac, MD, 20854, USA
| | - Chih-Hsin Lai
- Department of Dentistry Renai Branch, Taipei City Hospital, Taipei, 106, Taiwan
| | - Jehng-Kang Wang
- Department of Biochemistry, National Defense Medical Center, Taipei, 114, Taiwan
| | - Khee-Siang Chan
- Department of Intensive Care Medicine, Chi Mei Medical Center, No.901, Chung-Hwa Road, Yung-Kang District, Tainan City, 71004, Taiwan.
| | - Michael D Johnson
- Lombardi Comprehensive Cancer Center, Department of Oncology, W422 Research Building, Georgetown University, W416 Research Building, 3970 Reservoir Road, NW, Washington, DC, 20057, USA.
| | - Chen-Yong Lin
- Lombardi Comprehensive Cancer Center, Department of Oncology, W422 Research Building, Georgetown University, W416 Research Building, 3970 Reservoir Road, NW, Washington, DC, 20057, USA.
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3
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Huang N, Wang Q, Chen CY, Hu JM, Wang JK, Chang PY, Johnson MD, Lin CY. N-glycosylation on Asn-57 is required for the correct HAI-2 protein folding and protease inhibitory activity. Glycobiology 2023; 33:203-214. [PMID: 36637420 PMCID: PMC10114645 DOI: 10.1093/glycob/cwad002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 12/13/2022] [Accepted: 01/02/2023] [Indexed: 01/14/2023] Open
Abstract
Hepatocyte growth factor activator inhibitor (HAI)-2 is an integral membrane Kunitz-type serine protease inhibitor that regulates the proteolysis of matriptase and prostasin in a cell-type selective manner. The cell-type selective nature of HAI-2 function depends largely on whether the inhibitor and potential target enzymes are targeted to locations in close proximity. The N-glycan moiety of HAI-2 can function as a subcellular targeting signal. HAI-2 is synthesized with 1 of 2 different N-glycan modifications: one of oligomannose-type, which largely remains in the endoplasmic reticulum/GA, and another of complex-type, which is targeted toward the apical surface in vesicle-like structures, and could function as an inhibitor of matriptase and prostasin. HAI-2 contains 2 putative N-glycosylation sites, Asn-57 and Asn-94, point mutations of which were generated and characterized in this study. The protein expression profile of the HAI-2 mutants indicates that Asn-57, and not Asn-94, is responsible for the N-glycosylation of both HAI-2 species, suggesting that the form with oligomannose-type N-glycan is the precursor of the form with complex-type N-glycan. Unexpectedly, the vast majority of non-glycosylated HAI-2 is synthesized into multiple disulfide-linked oligomers, which lack protease inhibitory function, likely due to distorted conformations caused by the disarrayed disulfide linkages. Although forced expression of HAI-2 in HAI-2 knockout cells artificially enhances HAI-2 oligomerization, disulfide-linked HAI-2 oligomers can also be observed in unmodified cells. These results suggest that N-glycosylation on Asn-57 is required for folding into a functional HAI-2 with full protease suppressive activity and correct subcellular targeting signal.
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Affiliation(s)
- Nanxi Huang
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Qiaochu Wang
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Chao-Yang Chen
- School of Medicine, National Defense Medical Center, Taipei 114, Taiwan, ROC
- Division of Colorectal Surgery, Department of Surgery, Tri-Service General Hospital, Taipei 114, Taiwan, ROC
| | - Je-Ming Hu
- School of Medicine, National Defense Medical Center, Taipei 114, Taiwan, ROC
- Division of Colorectal Surgery, Department of Surgery, Tri-Service General Hospital, Taipei 114, Taiwan, ROC
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei 114, Taiwan, ROC
| | - Jehng-Kang Wang
- Department of Biochemistry, National Defense Medical Center, Taipei 114, Taiwan, ROC
| | - Ping-Ying Chang
- School of Medicine, National Defense Medical Center, Taipei 114, Taiwan, ROC
- Division of Hematology/Oncology, Department of internal medicine, Tri-Service General Hospital, Taipei 114, Taiwan, ROC
| | - Michael D Johnson
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
| | - Chen-Yong Lin
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, United States
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Liao AH, Chen YC, Chen CY, Chang SC, Chuang HC, Lin DL, Chiang CP, Wang CH, Wang JK. Mechanisms of ultrasound-microbubble cavitation for inducing the permeability of human skin. J Control Release 2022; 349:388-400. [PMID: 35787912 DOI: 10.1016/j.jconrel.2022.06.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 06/25/2022] [Accepted: 06/28/2022] [Indexed: 12/13/2022]
Abstract
We have previously reported that ultrasound (US)-mediated microbubble (MB) cavitation (US-MB) changed the permeability of the skin and significantly enhanced transdermal drug delivery (TDD) without changing the structure of the skin. In this study we found that US-MB enhanced TDD via disruption of epidermal cell-cell junctions and increased matriptase activity. Matriptase is a membrane-bound serine protease regulated by its inhibitor hepatocyte growth factor activator inhibitor-1 (HAI-1), and it is expressed in most epithelial tissues under physiologic conditions. Matriptase is expressed in mice after chronic exposure to UV radiation. This study found that US-MB can be used to monitor active matriptase, which rapidly formed the canonical 120-kDa matriptase-HAI-1 complex. These processes were observed in HaCaT human keratinocytes when matriptase activation was induced by US-MB. The results of immunoblot analysis indicated that the matriptase-HAI-1 complex can be detected from 10 min to 3 h after US-MB. Immunohistochemistry (IHC) of human skin revealed that US-MB rapidly increased the activated matriptase, which was observed in the basal layer, with this elevation lasting 3 h. After 3 h, the activated matriptase extended from the basal layer to the granular layer, and then gradually decayed from 6 to 12 h. Moreover, prostasin expression was observed in the epidermal granular layer to the spinous layer, and became more obvious in the granular layer after 3 h. Prostasin was also detected in the cytoplasm or on the cell membrane after 6 h. These results suggest that matriptase plays an important role in recovering from US-MB-induced epidermal cell-cell junction disruption within 6 h. US-MB is therefore a potentially effective method for noninvasive TDD in humans.
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Affiliation(s)
- Ai-Ho Liao
- Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan; Department of Biomedical Engineering, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yu-Chen Chen
- Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
| | - Chia-Yu Chen
- Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
| | - Shun-Cheng Chang
- Division of Plastic Surgery, Integrated Burn and Wound Care Center, Department of Surgery, Shuang-Ho Hospital, New Taipei City 235, Taiwan; Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
| | - Ho-Chiao Chuang
- Department of Mechanical Engineering, National Taipei University of Technology, Taipei 106344, Taiwan
| | - Dao-Lung Lin
- Spirit Scientific Co., Ltd. Taiwan Branch (Cayman), 12F-8, No. 99, Sec. 1, Xintai 5th Rd., Xizhi Dist., New Taipei City 221416, Taiwan
| | - Chien-Ping Chiang
- Department of Dermatology, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan; Department of Biochemistry, National Defense Medical Center, Taipei 11490, Taiwan
| | - Chih-Hung Wang
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei 11490, Taiwan; Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan.
| | - Jehng-Kang Wang
- Department of Biochemistry, National Defense Medical Center, Taipei 11490, Taiwan.
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5
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Sotiropoulou G, Zingkou E, Pampalakis G. Reconstructing the epidermal proteolytic cascades in health and disease. J Pathol 2022; 257:545-560. [PMID: 35218558 DOI: 10.1002/path.5888] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/24/2022] [Accepted: 02/24/2022] [Indexed: 11/08/2022]
Abstract
The epidermis is the outer stratified epithelium of the skin, forming the physical barrier that is indispensable for homeostasis. Epidermal proteolysis, mainly but not exclusively executed by kallikrein-related peptidases (KLKs), is tightly regulated to ensure maintenance of physiological skin renewal and an intact skin barrier. Perturbation of epidermal proteolytic networks is implicated in a wide array of rare and common skin pathologies of diverse genetic backgrounds. Recent studies of monogenic human skin diseases and newly developed animal models have revealed new mechanisms of regulation of proteolytic pathways in epidermal physiology and in disease states. These new data have challenged some accepted views, for example the role of matriptase in epidermal desquamation, which turned out to be restricted to mouse skin. The significance of PAR2 signaling in skin inflammation should also be reconsidered in the face of recent findings. Cumulatively, recent studies necessitate a sophisticated redefinition of the proteolytic and signaling pathways that operate in human skin. We elaborate how epidermal proteolysis is finely regulated at multiple levels, and in a spatial manner that was not taken into consideration so far, in which specific proteases are confined to distinct epidermal sublayers. Of interest, transglutaminases have emerged as regulators of epidermal proteolysis and desquamation by spatially fixing endogenous protease inhibitors, constituting regulatory factors that were not recognized before. Furthermore, new evidence suggests a link between proteolysis and lipid metabolism. By synthesis of established notions and recent discoveries, we provide an up-to-date critical parathesis of current knowledge and the extended complexity of proteolysis regulation and signaling pathways in skin. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Georgia Sotiropoulou
- Department of Pharmacy, School of Health Sciences, University of Patras, Rion-Patras, 265 04, Greece
| | - Eleni Zingkou
- Department of Pharmacy, School of Health Sciences, University of Patras, Rion-Patras, 265 04, Greece
| | - Georgios Pampalakis
- Department of Pharmacology-Pharmacognosy, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki, 541 24, Greece
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6
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Huang N, Barndt RB, Lu DD, Wang Q, Huang SM, Wang JK, Chang PY, Chen CY, Hu JM, Su HC, Johnson MD, Lin CY. The difference in the intracellular Arg/Lys-rich and EHLVY motifs contributes to distinct subcellular distribution of HAI-1 versus HAI-2. Hum Cell 2021; 35:163-178. [PMID: 34643933 DOI: 10.1007/s13577-021-00632-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 10/04/2021] [Indexed: 11/26/2022]
Abstract
The integral membrane, Kunitz-type, serine protease inhibitors, HAI-1 and HAI-2, closely resemble one another structurally and with regard to their specificity and potency against proteases. Structural complementarity between the Kunitz domains and serine protease domains renders the membrane-associated serine proteases, matriptase and prostasin, the primary target proteases of the HAIs. The shared biochemical enzyme-inhibitor relationships are, however, at odds with their behavior at the cellular level, where HAI-1 appears to be the default inhibitor of these proteases and HAI-2 a cell-type-selective inhibitor, even though they are widely co-expressed. The limited motility of these proteins caused by their membrane anchorages may require their co-localization within a certain distance to allow the establishment of a cellular level functional relationship between the proteases and the inhibitors. The differences in their subcellular localization with HAI-1 both inside the cell and on the cell surface, compared to HAI-2 predominately in intracellular granules has, therefore, been implicated in the differential manner of their control of matriptase and prostasin proteolysis. The targeting signals present in the intracellular domains of the HAIs are systematically investigated herein. Studies involving domain swap and point mutation, in combination with immunocytochemistry and cell surface biotinylation/avidin depletion, reveal that the different subcellular localization between the HAIs can largely be attributed to differences in the intracellular Arg/Lys-rich and EHLVY motifs. These intrinsic differences in the targeting signal render the HAIs as two independent rather than redundant proteolysis regulators.
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Affiliation(s)
- Nanxi Huang
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412, W416 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA
| | - Robert B Barndt
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412, W416 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA
| | - Dajun D Lu
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412, W416 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA
| | - Qiaochu Wang
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412, W416 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA
| | - Shih-Ming Huang
- Department of Biochemistry, National Defense Medical Center, Taipei, 114, Taiwan, ROC
| | - Jehng-Kang Wang
- Department of Biochemistry, National Defense Medical Center, Taipei, 114, Taiwan, ROC
| | - Ping-Ying Chang
- Division of Hematology/Oncology, Department of Internal Medicine, Tri-Service General Hospital, Taipei, Taiwan, ROC
- School of Medicine, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Chao-Yang Chen
- School of Medicine, National Defense Medical Center, Taipei, Taiwan, ROC
- Division of Colorectal Surgery, Department of Surgery, Tri-Service General Hospital Taipei, Taipei, Taiwan, ROC
| | - Je-Ming Hu
- School of Medicine, National Defense Medical Center, Taipei, Taiwan, ROC
- Division of Colorectal Surgery, Department of Surgery, Tri-Service General Hospital Taipei, Taipei, Taiwan, ROC
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Hui-Chen Su
- Department of Pharmacy, Chi-Mei Medical Center, Tainan, Taiwan, ROC.
| | - Michael D Johnson
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412, W416 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA.
| | - Chen-Yong Lin
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412, W416 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA.
- Department of Pharmacy, Chi-Mei Medical Center, Tainan, Taiwan, ROC.
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Lu DD, Gu Y, Li SWA, Barndt RJ, Huang SM, Wang JK, Su HC, Johnson MD, Lin CY. Targeted deletion of HAI-1 increases prostasin proteolysis but decreases matriptase proteolysis in human keratinocytes. Hum Cell 2021; 34:771-784. [PMID: 33486722 DOI: 10.1007/s13577-021-00488-1] [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: 11/17/2020] [Accepted: 01/10/2021] [Indexed: 10/22/2022]
Abstract
Epidermal differentiation and barrier function require well-controlled matriptase and prostasin proteolysis, in which the Kunitz-type serine protease inhibitor HAI-1 represents the primary enzymatic inhibitor for both proteases. HAI-1, however, also functions as a chaperone-like protein necessary for normal matriptase synthesis and intracellular trafficking. Furthermore, other protease inhibitors, such as antithrombin and HAI-2, can also inhibit matriptase and prostasin in solution or in keratinocytes. It remains unclear, therefore, whether aberrant increases in matriptase and prostasin enzymatic activity would be the consequence of targeted deletion of HAI-1 and so subsequently contribute to the epidermal defects observed in HAI-1 knockout mice. The impact of HAI-1 deficiency on matriptase and prostasin proteolysis was, here, investigated in HaCaT human keratinocytes. Our results show that HAI-1 deficiency causes an increase in prostasin proteolysis via increased protein expression and zymogen activation. It remains unclear, however, whether HAI-1 deficiency increases "net" prostasin enzymatic activity because all of the activated prostasin was detected in complexes with HAI-2, suggesting that prostasin enzymatic activity is still under tight control in HAI-1-deficient keratinocytes. Matriptase proteolysis is, however, unexpectedly suppressed by HAI-1 deficiency, as manifested by decreases in zymogen activation, shedding of active matriptase, and matriptase-dependent prostasin zymogen activation. This suppressed proteolysis results mainly from the reduced ability of HAI-1-deficient HaCaT cells to activate matriptase and the rapid inhibition of nascent active matriptase by HAI-2 and other yet-to-be-identified protease inhibitors. Our study provides novel insights with opposite impacts by HAI-1 deficiency on matriptase versus prostasin proteolysis in keratinocytes.
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Affiliation(s)
- Dajun D Lu
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA
| | - Yayun Gu
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA
| | - Sheng-Wen A Li
- School of Medicine, National Defense Medical Center, Taipei 114, Taiwan
| | - Robert J Barndt
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA
| | - Shih-Ming Huang
- Department of Biochemistry, National Defense Medical Center, Taipei 114, Taiwan
| | - Jehng-Kang Wang
- Department of Biochemistry, National Defense Medical Center, Taipei 114, Taiwan
| | - Hui Chen Su
- Department of Pharmacy, Chi-Mei Medical Center, Tainan, Taiwan.
| | - Michael D Johnson
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA.
| | - Chen-Yong Lin
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412 Research Building 3970 Reservoir Road NW, Washington, DC, 20057, USA.
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8
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Petrova E, Hovnanian A. Advances in understanding of Netherton syndrome and therapeutic implications. Expert Opin Orphan Drugs 2020. [DOI: 10.1080/21678707.2020.1857724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Evgeniya Petrova
- Laboratory of genetic skin diseases, Université de Paris, Imagine Institute, INSERM UMR1163, Paris, France
| | - Alain Hovnanian
- Laboratory of genetic skin diseases, Université de Paris, Imagine Institute, INSERM UMR1163, Paris, France
- Departement of Genetics, AP-HP, Hôpital Necker-Enfants Malades, Paris, France
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9
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Chang SC, Chiang CP, Lai CH, Du PWA, Hung YS, Chen YH, Yang HY, Fang HY, Lee SP, Tang HJ, Wang JK, Johnson MD, Lin CY. Matriptase and prostasin proteolytic activities are differentially regulated in normal and wounded skin. Hum Cell 2020; 33:990-1005. [PMID: 32617892 DOI: 10.1007/s13577-020-00385-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 06/02/2020] [Indexed: 01/27/2023]
Abstract
Orchestrated control of multiple overlapping and sequential processes is required for the maintenance of epidermal homeostasis and the response to and recovery from a variety of skin insults. Previous studies indicate that membrane-associated serine protease matriptase and prostasin play essential roles in epidermal development, differentiation, and barrier formation. The control of proteolysis is a highly regulated process, which depends not only on gene expression but also on zymogen activation and the balance between protease and protease inhibitor. Subcellular localization can affect the accessibility of protease inhibitors to proteases and, thus, also represents an integral component of the control of proteolysis. To understand how membrane-associated proteolysis is regulated in human skin, these key aspects of matriptase and prostasin were determined in normal and injured human skin by immunohistochemistry. This staining shows that matriptase is expressed predominantly in the zymogen form at the periphery of basal and spinous keratinocytes, and prostasin appears to be constitutively activated at high levels in polarized organelle-like structures of the granular keratinocytes in the adjacent quiescent skin. The membrane-associated proteolysis appears to be elevated via an increase in matriptase zymogen activation and prostasin protein expression in areas of skin recovering from epidermal insults. There was no noticeable change observed in other regulatory aspects, including the expression and tissue distribution of their cognate inhibitors HAI-1 and HAI-2. This study reveals that the membrane-associated proteolysis may be a critical epidermal mechanism involved in responding to, and recovering from, damage to human skin.
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Affiliation(s)
- Shun-Cheng Chang
- Division of Plastic Surgery, Integrated Burn and Wound Care Center, Department of Surgery, Shuang-Ho Hospital, New Taipei City, 235, Taiwan.,Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, 110, Taiwan
| | - Chien-Ping Chiang
- Department of Dermatology, Tri-Service General Hospital, Taipei, 114, Taiwan.,Department of Biochemistry, National Defense Medical Center, No. 161, Sec. 6, Ming-Chung E. Rd, Taipei, 114, Taiwan
| | - Chih-Hsin Lai
- Department of Dentistry Renai Branch, Taipei City Hospital, Taipei, 106, Taiwan
| | - Po-Wen A Du
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412 Research Building, 3970 Reservoir Road NW, Washington, DC, 20057, USA
| | - Yu-Sin Hung
- Department of Biochemistry, National Defense Medical Center, No. 161, Sec. 6, Ming-Chung E. Rd, Taipei, 114, Taiwan
| | - Yu-Hsuan Chen
- Department of Biochemistry, National Defense Medical Center, No. 161, Sec. 6, Ming-Chung E. Rd, Taipei, 114, Taiwan
| | - Hui-Yu Yang
- Department of Biochemistry, National Defense Medical Center, No. 161, Sec. 6, Ming-Chung E. Rd, Taipei, 114, Taiwan
| | - Hao-Yu Fang
- Department of Biochemistry, National Defense Medical Center, No. 161, Sec. 6, Ming-Chung E. Rd, Taipei, 114, Taiwan
| | - Shiao-Pieng Lee
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, 114, Taiwan.,Department of Oral and Maxillofacial Surgery, Tri-Service General Hospital, Taipei, 114, Taiwan
| | - Hung-Jen Tang
- Section of Infectious Diseases, Internal Medicine, Chi-Mei Medical Center, No.901, Chung-Hwa Rd., Yung-Kang Dist., Tainan City, 71004, Taiwan, ROC.
| | - Jehng-Kang Wang
- Department of Biochemistry, National Defense Medical Center, No. 161, Sec. 6, Ming-Chung E. Rd, Taipei, 114, Taiwan.
| | - Michael D Johnson
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412 Research Building, 3970 Reservoir Road NW, Washington, DC, 20057, USA
| | - Chen-Yong Lin
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, W412 Research Building, 3970 Reservoir Road NW, Washington, DC, 20057, USA.
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10
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Touati A, Saeidian AH, Youssefian L, Faghankhani M, Niaziorimi F, Pajouhanfar S, Vahidnezhad H, Uitto J. The matriptase-prostasin proteolytic cascade in dermatologic diseases. Exp Dermatol 2020; 29:580-587. [PMID: 32347581 DOI: 10.1111/exd.14104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 04/14/2020] [Accepted: 04/21/2020] [Indexed: 01/17/2023]
Abstract
The proper development and function of skin and hair are dependent on proteolytic activities. Specifically, the matriptase-prostasin cascade is a series of proteolytic reactions in the epidermis integral to normal regulation of desquamation. An increasing amount of research describing this pathway has recently become available, and the importance of this pathway is exhibited by the association of genetic defects in this pathway with human diseases of the skin and hair. Given the relevance of this pathway to dermatology, we provide a review of the current understanding of its relevance to distinct clinical entities, including ichthyosis-hypotrichosis and Netherton syndromes.
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Affiliation(s)
- Andrew Touati
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Amir Hossein Saeidian
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Leila Youssefian
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA.,Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoomeh Faghankhani
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Fatemeh Niaziorimi
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Sara Pajouhanfar
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Hassan Vahidnezhad
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA.,Biotechnology Research Center, Department of Molecular Medicine, Pasteur Institute of Iran, Tehran, Iran
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA.,Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
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11
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Vernone A, Ricca C, Merlo D, Pescarmona G, Silvagno F. The analysis of glutamate and glutamine frequencies in human proteins as marker of tissue oxygenation. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181891. [PMID: 31183125 PMCID: PMC6502398 DOI: 10.1098/rsos.181891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 03/07/2019] [Indexed: 06/09/2023]
Abstract
In this study, we investigated whether the relative abundance of glutamate and glutamine in human proteins reflects the availability of these amino acids (AAs) dictated by the cellular context. In particular, because hypoxia increases the conversion of glutamate to glutamine, we hypothesized that the ratio glutamate/glutamine could be related to tissue oxygenation. By histological, biochemical and genetic evaluation, we identified proteins expressed selectively by distinct cellular populations that are exposed in the same tissue to high or low oxygenation, or proteins codified by different chromosomal loci. Our biochemical assessment was implemented by software tools that calculated the absolute and the relative frequencies of all AAs contained in the proteins. Moreover, an agglomerative hierarchical cluster analysis was performed. In the skin model that has a strictly local metabolism, we demonstrated that the ratio glutamate/glutamine of the selected proteins was directly proportional to oxygenation. Accordingly, the proteins codified by the epidermal differentiation complex in the region 1q21.3 and by the lipase clustering region 10q23.31 showed a significantly lower ratio glutamate/glutamine compared with the nearby regions of the same chromosome. Overall, our results demonstrate that the estimation of glutamate/glutamine ratio can give information on tissue oxygenation and could be exploited as marker of hypoxia, a condition common to several pathologies.
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Affiliation(s)
- Annamaria Vernone
- Department of Oncology, University of Torino, Via Santena 5 bis, 10126 Torino, Italy
| | - Chiara Ricca
- Department of Oncology, University of Torino, Via Santena 5 bis, 10126 Torino, Italy
| | - Daniela Merlo
- Department of Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Gianpiero Pescarmona
- Department of Oncology, University of Torino, Via Santena 5 bis, 10126 Torino, Italy
| | - Francesca Silvagno
- Department of Oncology, University of Torino, Via Santena 5 bis, 10126 Torino, Italy
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12
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Pawar NR, Buzza MS, Antalis TM. Membrane-Anchored Serine Proteases and Protease-Activated Receptor-2-Mediated Signaling: Co-Conspirators in Cancer Progression. Cancer Res 2019; 79:301-310. [PMID: 30610085 DOI: 10.1158/0008-5472.can-18-1745] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/12/2018] [Accepted: 11/07/2018] [Indexed: 12/18/2022]
Abstract
Pericellular proteolysis provides a significant advantage to developing tumors through the ability to remodel the extracellular matrix, promote cell invasion and migration, and facilitate angiogenesis. Recent advances demonstrate that pericellular proteases can also communicate directly to cells by activation of a unique group of transmembrane G-protein-coupled receptors (GPCR) known as protease-activated receptors (PAR). In this review, we discuss the specific roles of one of four mammalian PARs, namely PAR-2, which is overexpressed in advanced stage tumors and is activated by trypsin-like serine proteases that are highly expressed or otherwise dysregulated in many cancers. We highlight recent insights into the ability of different protease agonists to bias PAR-2 signaling and the newly emerging evidence for an interplay between PAR-2 and membrane-anchored serine proteases, which may co-conspire to promote tumor progression and metastasis. Interfering with these pathways might provide unique opportunities for the development of new mechanism-based strategies for the treatment of advanced and metastatic cancers.
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Affiliation(s)
- Nisha R Pawar
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland.,Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Marguerite S Buzza
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland.,Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland.,University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland
| | - Toni M Antalis
- Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland. .,Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland.,University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland
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13
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Lee SP, Kao CY, Chang SC, Chiu YL, Chen YJ, Chen MHG, Chang CC, Lin YW, Chiang CP, Wang JK, Lin CY, Johnson MD. Tissue distribution and subcellular localizations determine in vivo functional relationship among prostasin, matriptase, HAI-1, and HAI-2 in human skin. PLoS One 2018; 13:e0192632. [PMID: 29438412 PMCID: PMC5811018 DOI: 10.1371/journal.pone.0192632] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 01/26/2018] [Indexed: 11/23/2022] Open
Abstract
The membrane-bound serine proteases prostasin and matriptase and the Kunitz-type protease inhibitors HAI-1 and HAI-2 are all expressed in human skin and may form a tightly regulated proteolysis network, contributing to skin pathophysiology. Evidence from other systems, however, suggests that the relationship between matriptase and prostasin and between the proteases and the inhibitors can be context-dependent. In this study the in vivo zymogen activation and protease inhibition status of matriptase and prostasin were investigated in the human skin. Immunohistochemistry detected high levels of activated prostasin in the granular layer, but only low levels of activated matriptase restricted to the basal layer. Immunoblot analysis of foreskin lysates confirmed this in vivo zymogen activation status and further revealed that HAI-1 but not HAI-2 is the prominent inhibitor for prostasin and matriptase in skin. The zymogen activation status and location of the proteases does not support a close functional relation between matriptase and prostasin in the human skin. The limited role for HAI-2 in the inhibition of matriptase and prostasin is the result of its primarily intracellular localization in basal and spinous layer keratinocytes, which probably prevents the Kunitz inhibitor from interacting with active prostasin or matriptase. In contrast, the cell surface expression of HAI-1 in all viable epidermal layers renders it an effective regulator for matriptase and prostasin. Collectively, our study suggests the importance of tissue distribution and subcellular localization in the functional relationship between proteases and protease inhibitors.
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Affiliation(s)
- Shiao-Pieng Lee
- School of Dentistry, National Defense Medical Center, Taipei, Taiwan
- Department of Dentistry, Tri-Service General Hospital, Taipei, Taiwan
| | - Chen-Yu Kao
- Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Shun-Cheng Chang
- Division of Plastic Surgery, Department of Surgery, Shuang-Ho Hospital, Taipei, Taiwan
- Department of Surgery, School of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yi-Lin Chiu
- Department of Biochemistry National Defense Medical Center, Taipei, Taiwan
- Lombardi Comprehensive Cancer Center, Department of Oncology Georgetown University Washington DC, United States of America
| | - Yen-Ju Chen
- Department of Biochemistry National Defense Medical Center, Taipei, Taiwan
| | | | - Chun-Chia Chang
- School of Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Wen Lin
- Department of Biochemistry National Defense Medical Center, Taipei, Taiwan
- Lombardi Comprehensive Cancer Center, Department of Oncology Georgetown University Washington DC, United States of America
| | - Chien-Ping Chiang
- Department of Biochemistry National Defense Medical Center, Taipei, Taiwan
- Department of Dermatology, Tri-Service General Hospital, Taipei, Taiwan
- * E-mail:
| | - Jehng-Kang Wang
- Department of Biochemistry National Defense Medical Center, Taipei, Taiwan
| | - Chen-Yong Lin
- Department of Dermatology, Tri-Service General Hospital, Taipei, Taiwan
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14
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Cheong Y, Kim C, Kim MB, Hwang JK. The anti-photoaging and moisturizing effects of Bouea macrophylla extract in UVB-irradiated hairless mice. Food Sci Biotechnol 2018; 27:147-157. [PMID: 30263735 PMCID: PMC6049745 DOI: 10.1007/s10068-017-0276-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 09/09/2017] [Accepted: 09/29/2017] [Indexed: 12/13/2022] Open
Abstract
Ultraviolet (UV) light, a main cause of photoaging, leads to collapse of skin structure, resulting in wrinkle formation and dehydration. The present study assessed the anti-photoaging and moisturizing effects of Bouea macrophylla extract (BRE). UVB-irradiated hairless mice were orally administered with BME (300 mg/kg/day) for 8 weeks. BME ameliorated wrinkle formation, skin thickening, and inelasticity. BME upregulated COL1A1, COL3A1, COL4A1, and COL7A1 mRNA levels through activation of the transforming growth factor-β (TGF-β)/Smad pathway, thereby recovering the content of collagen reduced by UVB. Further, BME suppressed UVB-induced matrix metalloproteinase (MMP)-3 and MMP-13 expression and inhibited MMP-2 and MMP-9 activity by mediating the mitogen-activated protein kinases (MAPKs)/activator protein-1 (AP-1). BME improved moisture content by stimulating the expression of cornified envelope proteins and filaggrin-processing enzymes. Overall, the results show that BME prevents photoaging and promotes moisturization in UVB-irradiated hairless mice, suggesting its potential as a nutraceutical candidate for anti-photoaging and moisturizing effects.
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Affiliation(s)
- Yongin Cheong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722 Republic of Korea
| | - Changhee Kim
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722 Republic of Korea
| | - Mi-Bo Kim
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722 Republic of Korea
| | - Jae-Kwan Hwang
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722 Republic of Korea
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15
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Modulating the selectivity of matriptase-2 inhibitors with unnatural amino acids. Eur J Med Chem 2017; 129:110-123. [DOI: 10.1016/j.ejmech.2017.02.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 01/19/2017] [Accepted: 02/05/2017] [Indexed: 12/12/2022]
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16
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Natural Endogenous Human Matriptase and Prostasin Undergo Zymogen Activation via Independent Mechanisms in an Uncoupled Manner. PLoS One 2016; 11:e0167894. [PMID: 27936035 PMCID: PMC5148038 DOI: 10.1371/journal.pone.0167894] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 11/22/2016] [Indexed: 11/19/2022] Open
Abstract
The membrane-associated serine proteases matriptase and prostasin are believed to function in close partnership. Their zymogen activation has been reported to be tightly coupled, either as a matriptase-initiated proteolytic cascade or through a mutually dependent mechanism involving the formation of a reciprocal zymogen activation complex. Here we show that this putative relationship may not apply in the context of human matriptase and prostasin. First, the tightly coupled proteolytic cascade between matriptase and prostasin might not occur when modest matriptase activation is induced by sphingosine 1-phospahte in human mammary epithelial cells. Second, prostasin is not required and/or involved in matriptase autoactivation because matriptase can undergo zymogen activation in cells that do not endogenously express prostasin. Third, matriptase is not required for and/or involved in prostasin activation, since activated prostasin can be detected in cells expressing no endogenous matriptase. Finally, matriptase and prostasin both undergo zymogen activation through an apparently un-coupled mechanism in cells endogenously expressing both proteases, such as in Caco-2 cells. In these human enterocytes, matriptase is detected primarily in the zymogen form and prostasin predominantly as the activated form, either in complexes with protease inhibitors or as the free active form. The negligible levels of prostasin zymogen with high levels of matriptase zymogen suggests that the reciprocal zymogen activation complex is likely not the mechanism for matriptase zymogen activation. Furthermore, high level prostasin activation still occurs in Caco-2 variants with reduced or absent matriptase expression, indicating that matriptase is not required and/or involved in prostasin zymogen activation. Collectively, these data suggest that any functional relationship between natural endogenous human matriptase and prostasin does not occur at the level of zymogen activation.
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