Paul A. Janmey

faculty photo
Professor of Physiology
Department: Physiology

Contact information
Institute for Medicine and Engineering
University of Pennsylvania
1010 Vagelos Research Laboratories
3340 Smith Walk
Philadelphia, PA 19104-6383
Office: 215 573-7380
Fax: 215 573-6815
Education:
A.B. (Chemistry and Philosophy)
Oberlin College, 1976.
Ph.D. (Physical Chemistry)
University of Wisconsin, 1982.
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Description of Research Expertise

Research Interests
cytoskeleton, phosphoinositide signalling, cell mechanics.

Key words: actin, PIP2, cytoskeleton, gel, astrocyte, fibrin, gelsolin.

Description of Research
Our lab studies several aspects of cell mechanics. In one project, we produce soft materials, usually hydrogels, to which cell adhesion proteins are linked to study how the stiffness of surfaces alters cell structure, function, and growth. Endothelial cells, fibroblasts, neurons and astrocytes each show unique dependence on substrate stiffness, and we seek to understand how they sense and respond to this mechanical cue. In related work we measure the structure and mechanics of cytoskeletal polymers using a variety of imaging, scattering, and rheologic methods. Further studies examine how changes in cell membrane structure mediated by inositol phospholipids lead to production of signals that remodel the cytoskeleton.

Rotation Projects
1. Image morphology and cytoskeletal changes in GFP-actin or GFP-vimentin expressing fibroblasts, endothelial cells, and other cell types grown of soft materials.

2. Fluorescence and atomic force microscopy of purified cytoskeletal polymers and associated motor proteins.

3. Use of fibrin gels as matrices for cell culture.

Lab personnel:
Robert Bucki, Fitzroy Byfield, Andrew Charlton, Yuning Chien, Katrina Cruz, Andrew Fang, Mariana Hernandez, Liesbeth Huisman, Maria Murray, Shaina Oake, JT Sauls, David Slochower, Erdem Tabdanov, Shang Tee, Eric Wang, Qi Wen, Tracy Wolfbiss

Description of Itmat Expertise

Dr. Janmey studies the mechanical properties of cells and tissues, the effect of material stiffness on cell structure and function, fibrin-based biomaterials for use in hemostasis and neural wound repair, plasma gelsolin as a marker and treatment for sepsis, and soft materials for use in adult stem cell applications.

Selected Publications

Fein David E, Bucki Robert, Byfield Fitzroy, Leszczynska Katarzyna, Janmey Paul A, Diamond Scott L: Novel cationic lipids with enhanced gene delivery and antimicrobial activity. Molecular pharmacology 78(3): 402-10, Sep 2010.

Bucki Robert, Leszczynska Katarzyna, Byfield Fitzroy J, Fein David E, Won Esther, Cruz Katrina, Namiot Andrzej, Kulakowska Alina, Namiot Zbigniew, Savage Paul B, Diamond Scott L, Janmey Paul A: Combined antibacterial and anti-inflammatory activity of a cationic disubstituted dexamethasone-spermine conjugate. Antimicrobial agents and chemotherapy 54(6): 2525-33, Jun 2010.

Levental I, Levental KR, Klein EA, Assoian R, Miller RT, Wells RG, Janmey PA: A simple indentation device for measuring micrometer-scale tissue stiffness. Journal of Physics-Condensed Matter 22: 194120, 2010.

Rothwell SW, Settle T, Wallace S, Dorsey J, Simpson D, Bowman JR, Janmey P, Sawyer E: The long term immunological response of swine after two exposures to a salmon thrombin and fibrinogen hemostatic bandage. Biologicals 2010 Notes: in press.

Levental Ilya, Byfield Fitzroy J, Chowdhury Pramit, Gai Feng, Baumgart Tobias, Janmey Paul A: Cholesterol-dependent phase separation in cell-derived giant plasma-membrane vesicles. The Biochemical journal 424(2): 163-7, Dec 2009.

Christian David A, Tian Aiwei, Ellenbroek Wouter G, Levental Ilya, Rajagopal Karthikan, Janmey Paul A, Liu Andrea J, Baumgart Tobias, Discher Dennis E: Spotted vesicles, striped micelles and Janus assemblies induced by ligand binding. Nature materials 8(10): 843-9, Oct 2009.

Talja Ija, Reimand Tiia, Uibo Oivi, Reimand Koit, Aun Silver, Talvik Tiina, Janmey Paul A, Uibo Raivo: Antibodies to neurofilaments. Annals of the New York Academy of Sciences 1173: 130-6, Sep 2009.

Klein Eric A, Yin Liqun, Kothapalli Devashish, Castagnino Paola, Byfield Fitzroy J, Xu Tina, Levental Ilya, Hawthorne Elizabeth, Janmey Paul A, Assoian Richard K: Cell-cycle control by physiological matrix elasticity and in vivo tissue stiffening. Current biology : CB 19(18): 1511-8, Sep 2009.

Kang H, Wen Q, Janmey P, Tang J, Conti E, Mackintosh F: Non-linear elasticity of stiff filament networks: Strain stiffening, negative normal stress, and filament alignment in fibrin gels. J Phys Chem B 2009 Notes: in press.

Leszczynska Katarzyna, Namiot Andrzej, Fein David E, Wen Qi, Namiot Zbigniew, Savage Paul B, Diamond Scott, Janmey Paul A, Bucki Robert: Bactericidal activities of the cationic steroid CSA-13 and the cathelicidin peptide LL-37 against Helicobacter pylori in simulated gastric juice. BMC microbiology 9: 187, 2009.

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Last updated: 03/18/2013
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