Jason DeRouchey is an Assistant Professor in the Department of Chemistry at the University of Kentucky. He received his B.S. degree in Chemistry from the University of Texas at Dallas in 1996. Professor DeRouchey then obtained a MS and PhD in Polymer Science and Engineering at the University of Massachusetts-AmHerst. He first began working with questions of dynamics and DNA as a Alexander von Humboldt Fellow working with Joachim Rädler at the Institute of Experimental Physics at the Ludwig Maximilians Universität (LMU) Munich. Dr. DeRouchey then joined the Laboratory of Physical and Structural Biology at the National Institute of Child Health & Human Development (NICHD) at the National Institutes of Health (NIH) as a IRTA fellow working with V. Adrian Parsegian.
Dr. DeRouchey's laboratory is broadly interested in understanding the forces, structures, and dynamics that govern the interaction of biologically significant macromolecular assemblies to address problems in biology and biomedicine. Using interdisciplinary methodologies in chemistry, physics, and medicine, we focus currently on issues related to DNA condensation in vitro and in vivo and the delivery of artificial gene constructs. Learning the strength, specificity, and reversibility in associates of biologically important macromolecules, typically in crowded environments, is crucial to our understanding of gene and cellular function and for effective and rational drug design.
DNA Condensation: from simple ions to complex proteins
In nature, DNA exists primarily in a highly condensed state. DNA packaging in the cell is typically protein mediated using, for example, histones (in eukaryotic nuclei) or protamines (in sperm cells). The scale of this compaction is immense. For a typcial human chromosome consisting of a single DNA approx. 5 cm in length, every cell thus has almost 2 meters of DNA compacted within its roughly 10 µm size. We work to address fundamental biophysical questions of DNA condensation by integrating x-ray scattering and osmotic stress experiments to investigate how cations mediate DNA-DNA intermolecular forces while extending from in vitro to in vivo packaging, such as mammalian sperm cells. Our long-term goal is to identify the biochemistry that underlies DNA packaging and mispackaging and understand the interrelationship to DNA damage, disease, and reproductive health.
Small molecule drug interactions with DNA
Many small molecules (such as drugs, ligands, etc.) are able to recognize and bind to single-or double-stranded nucleic acids, often inducing structural alterations. The unique double helix structures of DNA allows for binding through various modes including covalent binding (DNA-adducts), major or minor groove binding, and intercalation. Currently, little is known about small molecule drug interactions with highly packaged DNA that is typically found within cells. The reactivity of drugs and mutagens toward packaged DNA is presumably quite different from dilute DNA, and dependent on both accessibility and changes in DNA-DNA interaction energies. We are working on measuring directly the forces induced by these DNA drug interactions on DNA molecules in various states of condensation and correlating these forces to DNA packaging, DNA damage and disease.
Extracellular Gene Delivery: Nanoparticle Transport in Complex Media
In order to reach target cells, gene complexes must traverse the extracellular matrix (ECM), a crowded, interacting environment of biomacromolecules. Before accessing cells, a particle or a virus must also navigate through even messier milieus such as mucus or bacterial biofilms before successful delivery is possible. In these cases, one often finds that not only charged and uncharged polysaccharides and fibrous proteins of the ECM but even foreign DNA and bacteria can be entrapped in these gels. One can easily imagine the difficulties in interpreting diffusion data through systems which could have many specific and nonspecific interactions such as electrostatics, chemical binding, immobile barriers, and binding sites. For in vivo applicability, both transport properties and efficient delivery of intact gene complexes to the target tissue are crucial. Our group is involved in the study of fundamental questions using fluorescent techniques including fluorescence correlation spectroscopy (FCS) to gain insight into the transport and interactions of gene therapy contructs in complex biological systems.
Intracellular Gene Delivery: Understanding rate-limiting steps to efficient transfection
Endocytosis is the cellular process by which molecules, such as proteins, are absorbed from outside the cell membrane by engulfing within a membrane-bound vesicle. Once compartmentalized, these endosomes are either recycled back to the surface or are sorted for degradation through acidification. Since most non-viral carriers of DNA depend on endocytosis for their import into cells; endosomal release and the subsequent DNA release therefore corresponds to two of the most important barriers to efficient transfection. We are actively involved in using physical techniques including SAXS and FCS to better understand these mechanisms and ultimately engineer better optimized gene delivery systems.
- DeRouchey, J.; Rau, R. Role of Amino Acid Insertions on Intermolecular Forces between Arginine Peptide Condensed DNA Helices: Implications for Protamine-DNA Packaging in Sperm. J. Biol. Chem. 2011, ASAP.
- DeRouchey, J.; Rau, D. Salt Effects on Condensed Protamine-DNA Assemblies: Anion Binding and Weakening of Attraction. J Phys Chem B. 2011, 115(41):11888-94.
- DeRouchey, J.; Parsegian, V. A.; Rau, D. Cation Charge Dependence of the Forces Driving DNA Assembly. Biophysical Journal, 2010, in press.
- Hoenig, D.; DeRouchey, J.; Jungmann, R.; et al. Biophysical Characterization of Copolymer Protected Gene Vectors (COPROGs). Biomacromolecules. 2010, 11(7), 1802-1809.
- Podgornik, R.; Harries, D.; DeRouchey, J.; Parsegian, V. A.; Strey, H. H. Interactions in Macromolecular Complex Used as Nonviral Vectors for Gene Delivery. In Gene and Cell Therapy: Therapeutic Mechanisms and Strategies; Third Edition. Templeton, N.S. ed; Marcel Dekker: New York, 2009; pp 443-484.
- DeRouchey, J.; Schmidt, C.; Walker, G. F.; Plank, C.; Wagner, E.; Rädler, J. O. Monomolecular Assembly of siRNA and Poly(ethyleneglycol)-Peptide Copolymers. Biomacromolecules. 2008, 9 (2), 724-732.
- Pelisek, J.; Gaedtke, L.; DeRouchey, J.; et al. Optimized Lipopolyplex Formulations for Gene Transfer To Human Colon Carcinoma Cells Under in vitro Conditions. J. Gene Med. 2006, 8 (2), 186-197.
- DeRouchey, J.; Walker, G. F.; Wagner, E.; Rädler J. O.; Decorated Rods: A "Bottom-Up" Self- Assembly of Monomolecular DNA Complexes. J. Phys. Chem. B. 2006, 110 (10), 4548-4554.
- DeRouchey, J.; Netz, R. R.; Rädler J. O.; Structural Investigations of DNA-Polycation Complexes. European Physics Journal E – Soft Matter and Biological Physics. 2005, 16 (1), 17-28.
- DeRouchey, J.; Thurn-Albrecht, T.; Russell, T. P.; Kolb, R., "Block Copolymer Domain Reorientation In An Electric Field: An In-situ Small-Angle X-ray Scattering Study.“ Macromolecules. 2004, 37 (7), 2538-2543.
- Thurn-Albrecht, T.; DeRouchey, J.; Russell, T. P.; Kolb, R. Pathways towards electric field induced alignment of block copolymers. Macromolecules. 2002, 35 (21), 8106-8110.
- Thurn-Albrecht, T.; Steiner, R.; DeRouchey, J.; et al. Nanoscopic Templates from Oriented Block Copolymer Films. Advanced Materials. 2000, 12 (11), 787-791.
- Thurn-Albrecht, T.; DeRouchey, J.; Russell, T. P.; et al. Overcoming Interfacial Interactions with Electric Fields. Macromolecules. 2000, 33(9), 3250-3253.
- Boal, A.K.; Ilhan, F.; DeRouchey, J. E.; et al. Self-assembly of Nanoparticles into Structured Spherical and Network Aggregates. Nature. 2000, 404 (6779), 746-748.