Understanding the principles that govern life under extreme conditions will greatly enhance our ability to preserve clinical important cellular materials and help us to better understand and treat diseases that involve mitochondrial dysfunctions. Student training forms the core of my research program. Undergraduate and graduate student who would like to work in my laboratory should share my fascination with 'life at the limits' and 'lessons from nature' and are welcome to contact me about current research opportunities. For a more detailed description of current research projects please visit my laboratory homepage.
Anhydrobiosis (Life without Water)
Diapause and Anhydrobiosis in Embryos of Artemia franciscana: Metabolic Depression, LEA Proteins and Water Stress (with Steven C. Handel, Yuvraj Patil, Shumin Li, Nilay Charkraborty, Arpurva Borcar, Leaf C. Boswell, Daniel Moore, and Mehmet Toner), Cryobiology and Cryotechnology (2013)
Metabolic depression is typically correlated with extended survival of environmental challenge and energy-limitation in early...
Improved Tolerance to Salt and Water Stress in Drosophila melanogaster Cells Conferred by Late Embryogenesis Abundant Protein (with Matthew R. Marunde, Dilini A. Samarajeewa, John Anderson, Shumin Li, and Steven C. Hand), Journal of Insect Physiology (2013)
Mechanisms that govern anhydrobiosis involve the accumulation of highly hydrophilic macromolecules, such as late embryogenesis...
Late embryogenesis abundant proteins protect human hepatoma cells during acute desiccation (with Shumin Li, Nilay Chakraborty, Apurva Borcar, Mehmet Toner, and Steven C. Hand), Proceedings of the National Academy of Sciences (2012)
Expression of late embryogenesis abundant (LEA) proteins is highly correlated with desiccation tolerance in anhydrobiotic...
LEA Proteins during Water Stress: Not Just for Plants Anymore (with Steven C. Hand, Mehmet Toner, Leaf Boswell, and Daniel Moore), Annual Reviews of Physiology (2011)
Late embryogenesis abundant (LEA) proteins are extremely hydrophilic proteins that were first identified in land...
How do Animal Mitochondria Tolerate Water Stress? (with Steven C. Hand), Communicative & Integrative Biology (2009)
The vast majority of animal species do not tolerate severe water stress, but the encysted...
Apoptosis (Programmed Cell Death)
Long-Term Survival of Anoxia Despite Rapid ATP Decline in Embryos of the Annual Killifish Austrofundulus limnaeus (with Jason E. Podrabsky and Steven C. Hand), Journal of Experimental Zoology: Part A (2012)
Embryos of the annual killifish Austrofundulus limnaeus can survive for months in the complete absence...
Mechanisms of Apoptosis in Crustacea: What Conditions Induce Versus Suppress Cell Death? (with Grady Fortner, Suman Nag, and Steven C. Hand), Apoptosis (2010)
Arthropoda is the largest of all animal phyla and includes about 90% of extant species....
Mitochondria in energy-limited states: mechanisms that blunt the signaling of cell death (with Steven C. Hand), Journal of Experimental Biology (2008)
Cellular conditions experienced during energy-limited states – elevated calcium, shifts in cellular adenylate status, compromised...
Caspase activity during cell stasis: avoidance of apoptosis in an invertebrate extremophile, Artemia franciscana (with Steven C. Hand), American Journal of Physiology - Regulatory, Integrative, and Comparative Physiology (2007)
Evaluation of apoptotic processes downstream of the mitochondrion reveals caspase-9- and low levels of caspase-3-like...
Mitochondrial permeability transition in the crustacean Artemia franciscana: absence of a calcium-regulated pore in the face of profound calcium storage (with Kirk Hutchinson, Susan Laborde, and Steven C. Hand), American Journal of Physiology - Regulatory, Integrative, and Comparative Physiology (2005)
When mammalian mitochondria are exposed to high calcium and phosphate, a massive swelling, uncoupling of...
Allosteric Regulation (Respiratory Pigments)
Thermodynamics of effector binding to hemocyanin: influence of temperature (with Ariane Pott and Manfred K. Grieshaber), Archives of Biochemistry and Biophysics (2009)
Hemocyanins are allosterically regulated oxygen carriers freely dissolved in the blood of many crustaceans. The...
Allosteric Models for Multimeric Proteins: Oxygen-Linked Effector Binding in Hemocyanin (with Nadja Hellman, Heinz Decker, and Manfred K. Grieshaber), Biochemistry (2005)
In many crustaceans, changing concentrations of several low molecular weight compounds modulates hemocyanin oxygen binding,...
Binding of Urate and Caffeine to Hemocyanin Analyzed by Isothermal Titration Calorimetry (with Nadja Hellmann, Heinz Decker, and Manfred K. Grieshaber), Journal of Experimental Biology (2001)
Haemocyanin serves as an oxygen carrier in the haemolymph of decapod crustaceans. The oxygen-binding behaviour...
Binding of Urate and Caffeine to Hemocyanin of the Lobster Homarus Vulgaris (E.) As Studied by Isothermal Titration Calorimetry † (with Nadja Hellmann, Heinz Decker, and Manfred K. Grieshaber), Biochemistry (2000)
Hemocyanin serves as an oxygen carrier in the hemolymph of the European lobster Homarus Vulgaris....
Cell Stabilization (Preconditioning)
Metabolic Preconditioning of Mammalian Cells: Mimetic Agents for Hypoxia Lack Fidelity in Promoting Phosphorylation of Pyruvate Dehydrogenase (with Apurva Borcar, Mehmet Toner, and Steven C. Hand), Cell and Tissue Research (2012)
Induction of HIF-1α by oxygen limitation promotes increased phosphorylation and catalytic depression of mitochondrial pyruvate...
Metabolic Preconditioning of Cells with AICAR-Riboside: Improved Cryopreservation and Cell-Type Specific Impacts on Energetics and Proliferation (with Nilay Chakraborty, Matthew Clavenna, Mitali Banerjee, Xiang-Hong Liu, Mehmet Toner, and Steven C. Hand), Cryobiology (2011)
In species whose evolutionary history has provided natural tolerance to dehydration and freezing, metabolic depression...
Metabolic Restructuring during Energy-Limited States: Insights from Artemia franciscana Embryos and Other Animals (with Steven C. Hand, Apu Borcar, Yuvraj Patil, Joseph A. Covi, Julie A. Reynolds, and Mehmet Toner), Journal of Insect Physiology (2011)
Many life history stages of animals that experience environmental insults enter developmental arrested states that...
Trehalose Uptake through P2X7 Purinergic Channels Provides Dehydration Protection (with Gloria D. Elliott, Jennifer L. Cusick, Xiang-Hong Liu, Trudy Witt, Steven C. Hand, and Mehmet Toner), Cryobiology (2006)
The tetra-anionic form of ATP (ATP4-) is known to induce monovalent and divalent ion fluxes...
Cryopreservation of Human Hematopoietic Stem and Progenitor Cells Loaded with Trehalose: Transient Permeabilization via the Adenosine TriphosphateDependent P2Z Receptor Channel (with Sandhya S. Buchanan, Steven C. Hand, David W. Pyatt, and John F. Carpenter), Cell Preservation Technology (2005)
Hematopoietic stem and progenitor cells (HPCs) are a heterogenic population of cells used to treat...
Cell Stabilization (Lyopreservation)
Trehalose Transporter from African Chironomid Larvae Improves Desiccation Tolerance of Chinese Hamster Ovary Cells (with Nilay Chakraborty, Heidi Elmoazzen, Halong Vu, Martin Yarmush, Steven C. Hand, and Mehmet Toner), Cryobiology (2012)
Dry preservation has been explored as an energy-efficient alternative to cryopreservation, but the high sensitivity...
Cryopreservation of Spin-Dried Mammalian Cells (with Nilay Chakraborty, Jason Malsam, Alptekin Aksan, Steven C. Hand, and Mehmet Toner), PLoS One (2011)
This study reports an alternative approach to achieve vitrification where cells are pre-desiccated prior to...
Spin-Drying Technique for Lyopreservation of Mammalian Cells (with Nilay Chakraborty, Anthony Chang, Heidi Elmoazzen, Steven C. Hand, and Mehmet Toner), Annals of Biomedical Engineering (2011)
Stabilization of cellular material in the presence of glass-forming sugars at ambient temperatures is a...
Desiccation Kinetics and Biothermodynamics of Glass Forming Trehalose Solutions in Thin Films (with Xiaoming He, Alex Fowler, Steven C. Hand, and Mehmet Toner), Annals of Biomedical Engineering (2008)
In this study, the desiccation kinetics of aqueous trehalose solutions were investigated numerically by solving...
Patent
Preservation of eukaryotic cells using reversible pore formation (with Steven C. Hand) (2008)
A method is disclosed for reliably stabilizing eukaryotic cells that express the P2X.sub.7 receptor channel,...