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Rogers MT, Gard AL, Gaibler R, Mulhern TJ, Strelnikov R, Azizgolshani H, Cain BP, Isenberg BC, Haroutunian NJ, Raustad NE, Keegan PM, Lech MP, Tomlinson L, Borenstein JT, Charest JL, Williams C. A high-throughput microfluidic bilayer co-culture platform to study endothelial-pericyte interactions. Sci Rep 2021; 11:12225. [PMID: 34108507 PMCID: PMC8190127 DOI: 10.1038/s41598-021-90833-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/17/2021] [Indexed: 01/27/2023] Open
Abstract
Microphysiological organ-on-chip models offer the potential to improve the prediction of drug safety and efficacy through recapitulation of human physiological responses. The importance of including multiple cell types within tissue models has been well documented. However, the study of cell interactions in vitro can be limited by complexity of the tissue model and throughput of current culture systems. Here, we describe the development of a co-culture microvascular model and relevant assays in a high-throughput thermoplastic organ-on-chip platform, PREDICT96. The system consists of 96 arrayed bilayer microfluidic devices containing retinal microvascular endothelial cells and pericytes cultured on opposing sides of a microporous membrane. Compatibility of the PREDICT96 platform with a variety of quantifiable and scalable assays, including macromolecular permeability, image-based screening, Luminex, and qPCR, is demonstrated. In addition, the bilayer design of the devices allows for channel- or cell type-specific readouts, such as cytokine profiles and gene expression. The microvascular model was responsive to perturbations including barrier disruption, inflammatory stimulation, and fluid shear stress, and our results corroborated the improved robustness of co-culture over endothelial mono-cultures. We anticipate the PREDICT96 platform and adapted assays will be suitable for other complex tissues, including applications to disease models and drug discovery.
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Affiliation(s)
- Miles T Rogers
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA.,Raytheon BBN Technologies, Synthetic Biology, 10 Moulton St, Cambridge, MA, 02138, USA
| | - Ashley L Gard
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
| | - Robert Gaibler
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
| | - Thomas J Mulhern
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
| | - Rivka Strelnikov
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA.,Microsoft Corporation, 1 Memorial Drive, Cambridge, MA, 02142, USA
| | - Hesham Azizgolshani
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
| | - Brian P Cain
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
| | - Brett C Isenberg
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
| | - Nerses J Haroutunian
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
| | - Nicole E Raustad
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA.,Department of Biology, Northeastern University, 360 Huntington Ave, Boston, MA, 02115, USA
| | - Philip M Keegan
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA.,Department of Biomedical Engineering, University of Wisconsin Madison, 1550 Engineering Dr, Madison, WI, 53706, USA
| | | | | | - Jeffrey T Borenstein
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA
| | - Joseph L Charest
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA.
| | - Corin Williams
- The Charles Stark Draper Laboratory Inc., 555 Technology Square, Cambridge, MA, 02139, USA.
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Tan K, Coppeta J, Azizgolshani H, Isenberg BC, Keegan PM, Cain BP, Patterson AJ, Kim ES, Kratchman LB, Rogers M, Haroutunian N, Newlin V, Golmon S, Tandon V, Lu M, Gosset JR, Vedula EM, Charest JL, Bale SS. Correction: A high-throughput microfluidic microphysiological system (PREDICT-96) to recapitulate hepatocyte function in dynamic, re-circulating flow conditions. Lab Chip 2020; 20:3653. [PMID: 32756648 DOI: 10.1039/d0lc90069a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Correction for 'A high-throughput microfluidic microphysiological system (PREDICT-96) to recapitulate hepatocyte function in dynamic, re-circulating flow conditions' by Kelly Tan et al., Lab Chip, 2019, 19, 1556-1566, DOI: .
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Affiliation(s)
- Kelly Tan
- Draper, 555 Technology Square, Cambridge, MA 02138, USA.
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Song H, Keegan PM, Anbazhakan S, Rivera CP, Feng Y, Omojola VO, Clark AA, Cai S, Selma J, Gleason RL, Botchwey EA, Huo Y, Tan W, Platt MO. Sickle Cell Anemia Mediates Carotid Artery Expansive Remodeling That Can Be Prevented by Inhibition of JNK (c-Jun N-Terminal Kinase). Arterioscler Thromb Vasc Biol 2020; 40:1220-1230. [PMID: 32160775 DOI: 10.1161/atvbaha.120.314045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
OBJECTIVE Sickle cell anemia (SCA) causes chronic inflammation and multiorgan damage. Less understood are the arterial complications, most evident by increased strokes among children. Proteolytic mechanisms, biomechanical consequences, and pharmaceutical inhibitory strategies were studied in a mouse model to provide a platform for mechanistic and intervention studies of large artery damage due to sickle cell disease. Approach and Results: Townes humanized transgenic mouse model of SCA was used to test the hypothesis that elastic lamina and structural damage in carotid arteries increased with age and was accelerated in mice homozygous for SCA (sickle cell anemia homozygous genotype [SS]) due to inflammatory signaling pathways activating proteolytic enzymes. Elastic lamina fragmentation observed by 1 month in SS mice compared with heterozygous littermate controls (sickle cell trait heterozygous genotype [AS]). Positive immunostaining for cathepsin K, a powerful collagenase and elastase, confirmed accelerated proteolytic activity in SS carotids. Larger cross-sectional areas were quantified by magnetic resonance angiography and increased arterial compliance in SS carotids were also measured. Inhibiting JNK (c-jun N-terminal kinase) signaling with SP600125 significantly reduced cathepsin K expression, elastin fragmentation, and carotid artery perimeters in SS mice. By 5 months of age, continued medial thinning and collagen degradation was mitigated by treatment of SS mice with JNK inhibitor. CONCLUSIONS Arterial remodeling due to SCA is mediated by JNK signaling, cathepsin proteolytic upregulation, and degradation of elastin and collagen. Demonstration in Townes mice establishes their utility for mechanistic studies of arterial vasculopathy, related complications, and therapeutic interventions for large artery damage due to SCA.
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Affiliation(s)
- Hannah Song
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.)
| | - Philip M Keegan
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.)
| | - Suhaas Anbazhakan
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.)
| | - Christian P Rivera
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.).,Department of Mechanics and Engineering Science at Peking University, Beijing, China (C.P.R., Y.F., Y.H., W.T.)
| | - Yundi Feng
- Department of Mechanics and Engineering Science at Peking University, Beijing, China (C.P.R., Y.F., Y.H., W.T.)
| | - Victor O Omojola
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.)
| | - Alexus A Clark
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.)
| | - Shuangyi Cai
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.)
| | - Jada Selma
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.)
| | - Rudolph L Gleason
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.).,Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta (R.L.G., E.A.B., M.O.P.)
| | - Edward A Botchwey
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.).,Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta (R.L.G., E.A.B., M.O.P.)
| | - Yunlong Huo
- Department of Mechanics and Engineering Science at Peking University, Beijing, China (C.P.R., Y.F., Y.H., W.T.)
| | - Wenchang Tan
- Department of Mechanics and Engineering Science at Peking University, Beijing, China (C.P.R., Y.F., Y.H., W.T.)
| | - Manu O Platt
- From the Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta (H.S., P.M.K., S.A., C.P.R., V.O.O., A.A.C., S.C., J.S., R.L.G., E.A.B., M.O.P.).,Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta (R.L.G., E.A.B., M.O.P.)
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Song H, Keegan PM, Denby AJ, Clark A, Selma J, Anbazhakan S, Botchwey EA, Platt M. Elastic lamina fragmentation in sickle mice can be rescued by JNK‐Cathepsin inhibition. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.676.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Hannah Song
- Biomedical EngineeringGeorgia Institue of TechnologyAtlantaGA
| | | | | | - Alexus Clark
- Biomedical EngineeringGeorgia Institue of TechnologyAtlantaGA
| | - Jada Selma
- Biomedical EngineeringGeorgia Institue of TechnologyAtlantaGA
| | | | | | - Manu Platt
- Biomedical EngineeringGeorgia Institue of TechnologyAtlantaGA
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5
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Keegan PM, Anbazhakan S, Kang B, Pace BS, Platt MO. Biomechanical and biochemical regulation of cathepsin K expression in endothelial cells converge at AP-1 and NF-κB. Biol Chem 2016; 397:459-68. [PMID: 26760306 DOI: 10.1515/hsz-2015-0244] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/04/2016] [Indexed: 11/15/2022]
Abstract
Cathepsins K and V are powerful elastases elevated in endothelial cells by tumor necrosis factor-α (TNFα) stimulation and disturbed blood flow both of which contribute to inflammation-mediated arterial remodeling. However, mechanisms behind endothelial cell integration of biochemical and biomechanical cues to regulate cathepsin production are not known. To distinguish these mechanisms, human aortic endothelial cells (HAECs) were stimulated with TNFα and exposed to pro-remodeling or vasoprotective shear stress profiles. TNFα upregulated cathepsin K via JNK/c-jun activation, but vasoprotective shear stress inhibited TNFα-stimulated cathepsin K expression. JNK/c-jun were still phosphorylated, but cathepsin K mRNA levels were significantly reduced to almost null indicating separate biomechanical regulation of cathepsin K by shear stress separate from biochemical stimulation. Treatment with Bay 11-7082, an inhibitor of IκBα phosphorylation, was sufficient to block induction of cathepsin K by both pro-remodeling shear stress and TNFα, implicating NF-κB as the biomechanical regulator, and its protein levels were reduced in HAECs by vasoprotective shear stress. In conclusion, NF-κB and AP-1 activation were necessary to activate cathepsin K expression in endothelial cells, highlighting integration of biochemical and biomechanical stimuli to control cathepsins K and V, powerful elastases implicated for arterial remodeling due to chronic inflammation and disturbed blood flow.
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Platt MO, Evans D, Keegan PM, McNamara L, Parker IK, Roberts LM, Caulk AW, Gleason RL, Seifu D, Amogne W, Penny C. Low-Cost Method to Monitor Patient Adherence to HIV Antiretroviral Therapy Using Multiplex Cathepsin Zymography. Mol Biotechnol 2016; 58:56-64. [PMID: 26589706 DOI: 10.1007/s12033-015-9903-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Monitoring patient adherence to HIV antiretroviral therapy (ART) by patient survey is inherently error prone, justifying a need for objective, biological measures affordable in low-resource settings where HIV/AIDS epidemic is highest. In preliminary studies conducted in Ethiopia and South Africa, we observed loss of cysteine cathepsin activity in peripheral blood mononuclear cells of HIV-positive patients on ART. We optimized a rapid protocol for multiplex cathepsin zymography to quantify cysteine cathepsins, and prospectively enrolled 350 HIV-positive, ART-naïve adults attending the Themba Lethu Clinic, Johannesburg, South Africa, to test if suppressed cathepsin activity could be a biomarker of ART adherence (103 patients were included in final analysis). Poor adherence was defined as detectable viral load (>400 copies/ml) or simplified medication adherence questionnaire, 4-6 months after ART initiation. 86 % of patients with undetectable viral loads after 6 months were cathepsin negative, and cathepsin-positive patients were twice as likely to have detectable viral loads (RR 2.32 95 % CI 1.26-4.29). Together, this demonstrates proof of concept that multiplex cathepsin zymography may be an inexpensive, objective method to monitor patient adherence to ART. Low cost of this electrophoresis-based assay makes it a prime candidate for implementation in resource-limited settings.
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Affiliation(s)
- Manu O Platt
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 315 Ferst Drive, IBB 1308, Atlanta, GA, 30332, USA. .,The Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA.
| | - Denise Evans
- Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, University of the Witwatersrand, Johannesburg, South Africa
| | - Philip M Keegan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 315 Ferst Drive, IBB 1308, Atlanta, GA, 30332, USA.,The Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Lynne McNamara
- Clinical HIV Research Unit, Department of Internal Medicine, School of Clinical Medicine, University of the Witwatersrand, Johannesburg, South Africa
| | - Ivana K Parker
- The Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA.,The George W. Woodruff School of Mechanical Engineering, Atlanta, GA, USA
| | - LaDeidra M Roberts
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 315 Ferst Drive, IBB 1308, Atlanta, GA, 30332, USA.,The Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Alexander W Caulk
- The Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA.,The George W. Woodruff School of Mechanical Engineering, Atlanta, GA, USA
| | - Rudolph L Gleason
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 315 Ferst Drive, IBB 1308, Atlanta, GA, 30332, USA.,The Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA.,The George W. Woodruff School of Mechanical Engineering, Atlanta, GA, USA
| | - Daniel Seifu
- Department of Biochemistry, Addis Ababa University, Addis Ababa, Ethiopia
| | - Wondwossen Amogne
- Department of Internal Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | - Clement Penny
- Oncology Division, Department of Internal Medicine, University of the Witwatersrand, Johannesburg, South Africa
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Fan NK, Keegan PM, Platt MO, Averett RD. Experimental and imaging techniques for examining fibrin clot structures in normal and diseased states. J Vis Exp 2015:e52019. [PMID: 25867016 DOI: 10.3791/52019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Fibrin is an extracellular matrix protein that is responsible for maintaining the structural integrity of blood clots. Much research has been done on fibrin in the past years to include the investigation of synthesis, structure-function, and lysis of clots. However, there is still much unknown about the morphological and structural features of clots that ensue from patients with disease. In this research study, experimental techniques are presented that allow for the examination of morphological differences of abnormal clot structures due to diseased states such as diabetes and sickle cell anemia. Our study focuses on the preparation and evaluation of fibrin clots in order to assess morphological differences using various experimental assays and confocal microscopy. In addition, a method is also described that allows for continuous, real-time calculation of lysis rates in fibrin clots. The techniques described herein are important for researchers and clinicians seeking to elucidate comorbid thrombotic pathologies such as myocardial infarctions, ischemic heart disease, and strokes in patients with diabetes or sickle cell disease.
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Affiliation(s)
- Natalie K Fan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University School of Medicine
| | - Philip M Keegan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University School of Medicine
| | - Manu O Platt
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University School of Medicine; Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology
| | - Rodney D Averett
- Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology;
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8
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Keegan PM, Keifer OP, Parker IL, Keilholz SD, Platt MO. Abstract TP261: Spontaneous Strokes In Sickle Cell Transgenic Mice Captured Ex Vivo With Magnetic Resonance Imaging. Stroke 2013. [DOI: 10.1161/str.44.suppl_1.atp261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
With 11% of children with sickle cell disease (SCD) having strokes, many as early as 1 to 5 years old, the underlying mechanisms are still unclear, and it is still unknown why this subpopulation has greater risk. More will suffer from subclinical silent strokes that cause cognitive rather than physical impairments. Sickling of red blood cells due to a point mutation in hemoglobin induces chronic inflammation and vascular remodeling in SCD. We have previously shown that powerful proteases, cathepsins, are activated in SCD to promote vascular remodeling that could lead to stroke. However, a mouse model of detectable sickle cell stroke is required to study mechanism and intervention strategies. Here, we used Townes sickle transgenic mouse, with murine hemoglobin knocked out and replaced with human, sickle hemoglobin, to test the hypothesis that sickle transgenic mice have MRI detectable strokes and increased cathepsin proteolytic activity. Three mice homozygous for sickle mutation (SS) and 6 heterozygous littermate controls (AS) were perfused at 8 weeks. Brains were isolated, embedded in gadolinium-agarose, and scanned using a Bruker 9.4 Tesla magnet with a T2-weighted protocol (TE = 13.4 ms. TR= 10,000, 512 x 512 x 70). Of the 3 SS mice, 2 had abnormalities suggestive of stroke (Figure 1, red arrows), with none noted in the AS controls. Separately, immunohistochemistry with anti-cathepsin K antibody indicated a gene dosing effect of sickle allele on cathepsin K expression (SS>AS>AA), verified in aorta homogenates by multiplex cathepsin zymography assays (n=3, p<.05). To conclude, we have identified strokes in sickle transgenic mice with T2 images. These mouse stroke scans, without occlusive or chemical intervention, will be an improved model to test spontaneous stroke interventions specific to sickle cell disease including targeting upregulated cathepsins.
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Wilder CL, Park KY, Keegan PM, Platt MO. Manipulating substrate and pH in zymography protocols selectively distinguishes cathepsins K, L, S, and V activity in cells and tissues. Arch Biochem Biophys 2011; 516:52-7. [PMID: 21982919 PMCID: PMC3221864 DOI: 10.1016/j.abb.2011.09.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2011] [Revised: 09/23/2011] [Accepted: 09/25/2011] [Indexed: 11/15/2022]
Abstract
Cathepsins K, L, S, and V are cysteine proteases that have been implicated in tissue-destructive diseases such as atherosclerosis, tumor metastasis, and osteoporosis. Among these four cathepsins are the most powerful human collagenases and elastases, and they share 60% sequence homology. Proper quantification of mature, active cathepsins has been confounded by inhibitor and reporter substrate cross-reactivity, but is necessary to develop properly dosed therapeutic applications. Here, we detail a method of multiplex cathepsin zymography to detect and distinguish the activity of mature cathepsins K, L, S, and V by exploiting differences in individual cathepsin substrate preferences, pH effects, and electrophoretic mobility under non-reducing conditions. Specific identification of cathepsins K, L, S, and V in one cell/tissue extract was obtained with cathepsin K (37 kDa), V (35 kDa), S (25 kDa), and L (20 kDa) under non-reducing conditions. Cathepsin K activity disappeared and V remained when incubated at pH 4 instead of 6. Application of this antibody free, species independent, and medium-throughput method was demonstrated with primary human monocyte-derived macrophages and osteoclasts, endothelial cells stimulated with inflammatory cytokines, and normal and cancer lung tissues, which identified elevated cathepsin V in lung cancer.
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Affiliation(s)
- Catera L. Wilder
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332
| | - Keon-Young Park
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332
| | - Philip M. Keegan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332
| | - Manu O. Platt
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332
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Li WA, Barry ZT, Cohen JD, Wilder CL, Deeds RJ, Keegan PM, Platt MO. Detection of femtomole quantities of mature cathepsin K with zymography. Anal Biochem 2010; 401:91-8. [PMID: 20206119 DOI: 10.1016/j.ab.2010.02.035] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 02/25/2010] [Accepted: 02/26/2010] [Indexed: 11/26/2022]
Abstract
Cathepsin K, the most potent mammalian collagenase, has been implicated in osteoporosis, cancer metastasis, atherosclerosis, and arthritis. Although procathepsin K is stable and readily detected, the active mature cathepsin K eludes detection by in vitro methods due to its shorter half-life and inactivation at neutral pH. We describe, for the first time, reliable detection, visualization, and quantification of mature cathepsin K to femtomole resolution using gelatin zymography. The specificity of the method was validated with cathepsin K knockdown using small interfering RNA (siRNA) transfection of human monocyte-derived macrophages, and enzymatic activity confirmed with benzyloxycarbonyl-glycine-proline-arginine-7-amino-4-methylcoumarin (Z-GPR-AMC) substrate hydrolysis was fit to a computational model of enzyme kinetics. Furthermore, cathepsin K zymography was used to show that murine osteoclasts secrete more cathepsin K than is stored intracellularly, and this was opposite to the behavior of the macrophages from which they were differentiated. In summary, this inexpensive, species-independent, antibody-free protocol describes a sensitive method with broad potential to elucidate previously undetectable cathepsin K activity.
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Affiliation(s)
- Weiwei A Li
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
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