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Full-Text Articles in Life Sciences
Cryopreservation Of Hepatocyte (Hepg2) Cell Monolayers: Impact Of Trehalose, Blake Stokich, Quinn Osgood, David Grimm, Shhyam Moorthy, Nilay Chakraborty, Michael A. Menze
Cryopreservation Of Hepatocyte (Hepg2) Cell Monolayers: Impact Of Trehalose, Blake Stokich, Quinn Osgood, David Grimm, Shhyam Moorthy, Nilay Chakraborty, Michael A. Menze
Faculty Research & Creative Activity
A simple method to cryogenically preserve hepatocyte monolayers is currently not available but such a technique would facilitate numerous applications in the field of biomedical engineering, cell line development, and drug screening. We investigated the effect of trehalose and dimethyl sulfoxide (Me2SO) in cryopreservation of human hepatocellular carcinoma (HepG2) cells in suspension and monolayer formats. HepG2 cell monolayers were incubated for 24 h at varying concentrations of trehalose (50–150 mM) prior to cryopreservation to identify the optimum concentration for such preincubation. When trehalose alone was used as the cryoprotective agent (CPA), cells in monolayer format did not survive freezing while …
Metabolic Preconditioning Of Mammalian Cells: Mimetic Agents For Hypoxia Lack Fidelity In Promoting Phosphorylation Of Pyruvate Dehydrogenase, Apurva Borcar, Michael A. Menze, Mehmet Toner, Steven C. Hand
Metabolic Preconditioning Of Mammalian Cells: Mimetic Agents For Hypoxia Lack Fidelity In Promoting Phosphorylation Of Pyruvate Dehydrogenase, Apurva Borcar, Michael A. Menze, Mehmet Toner, Steven C. Hand
Faculty Research & Creative Activity
Induction of HIF-1α by oxygen limitation promotes increased phosphorylation and catalytic depression of mitochondrial pyruvate dehydrogenase (PDH) and an enhanced glycolytic poise in cells. Cobalt chloride and desferrioxamine are widely used as mimics for hypoxia because they increase the levels of HIF-1α. We evaluated the ability of these agents to elicit selected physiological responses to hypoxia as a means to metabolically precondition mammalian cells, but without the detrimental effects of hypoxia. We show that, while CoCl2 does increase HIF-1α in a dose-dependent manner, it unexpectedly and strikingly decreases PDH phosphorylation at E1α sites 1, 2, and 3 (Ser293, Ser300, and …
Metabolic Restructuring During Energy-Limited States: Insights From Artemia Franciscana Embryos And Other Animals, Steven C. Hand, Michael A. Menze, Apu Borcar, Yuvraj Patil, Joseph A. Covi, Julie A. Reynolds, Mehmet Toner
Metabolic Restructuring During Energy-Limited States: Insights From Artemia Franciscana Embryos And Other Animals, Steven C. Hand, Michael A. Menze, Apu Borcar, Yuvraj Patil, Joseph A. Covi, Julie A. Reynolds, Mehmet Toner
Faculty Research & Creative Activity
Many life history stages of animals that experience environmental insults enter developmental arrested states that are characterized by reduced cellular proliferation, with or without a concurrent reduction in overall metabolism. In the case of the most profound metabolic arrest reported in invertebrates, i.e., anaerobic quiescence in Artemia franciscana embryos, acidification of the intracellular milieu is a major factor governing catabolic and anabolic downregulation. Release of ion gradients from intracellular compartments is the source for approximately 50% of the proton equivalents needed for the 1.5 unit acidification that is observed. Recovery from the metabolic arrest requires re-sequestration of the protons with …
Trehalose Uptake Through P2x7 Purinergic Channels Provides Dehydration Protection, Gloria D. Elliott, Jennifer L. Cusick, Xiang-Hong Liu, Michael A. Menze, Trudy Witt, Steven C. Hand, Mehmet Toner
Trehalose Uptake Through P2x7 Purinergic Channels Provides Dehydration Protection, Gloria D. Elliott, Jennifer L. Cusick, Xiang-Hong Liu, Michael A. Menze, Trudy Witt, Steven C. Hand, Mehmet Toner
Faculty Research & Creative Activity
The tetra-anionic form of ATP (ATP4-) is known to induce monovalent and divalent ion fluxes in cells that express purinergic P2X7 receptors (Steinberg et al., 1987; Sung et al., 1985), and with sustained application of ATP it has been shown that dyes as large as 831 daltons can permeate the cell membrane (Steinberg et al, 1987). The current study explores the kinetics of loading α,α-trehalose (342 daltons) into ATP stimulated J774.A1 cells, which are known to express the purinergic P2X7 receptor (Steinberg et al., 1987). Cells that were incubated at 37 ̊C in a 50 mM phosphate buffer (pH 7.0) …
Trehalose Loading Through The Mitochondrial Permeability Transition Pore Enhances Desiccation Tolerance In Rat Liver Mitochondria, Xiang-Hong Liu, Alptekin Aksan, Michael A. Menze, Steven C. Hand, Mehmet Toner
Trehalose Loading Through The Mitochondrial Permeability Transition Pore Enhances Desiccation Tolerance In Rat Liver Mitochondria, Xiang-Hong Liu, Alptekin Aksan, Michael A. Menze, Steven C. Hand, Mehmet Toner
Faculty Research & Creative Activity
Trehalose has extensively been used to improve the desiccation tolerance of mammalian cells. To test whether trehalose improves desiccation tolerance of mammalian mitochondria, we introduced trehalose into the matrix of isolated rat liver mitochondria by reversibly permeabilizing the inner membrane using the mitochondrial permeability transition pore (MPTP). Measurement of the trehalose concentration inside mitochondria using high perfOrmance liquid chromatography showed that the sugar permeated rapidly into the matrix upon opening the MPTP. The concentration of intra matrix trehalose reached 0.29 mmoVmg protein (-190 mM) in 5 min. Mitochondria, with and without trehalose loaded into the matrix, were desiccated in a …