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Full-Text Articles in Life Sciences

Deciphering The Role Of Mitochondrial Physiology And Thermal Acclimation In Shaping Whole Organismal Performance Of An Invasive Forest Pest, Essa Alrashdi Jan 2022

Deciphering The Role Of Mitochondrial Physiology And Thermal Acclimation In Shaping Whole Organismal Performance Of An Invasive Forest Pest, Essa Alrashdi

Masters Theses

Environmental factors such as temperature are substantial determinants of the spongy moth, L. dispar, distribution, reproduction, and growth. Accumulating energy reserves at the larval stage is particularly important to L. dispar, since the larvae metamorphose into a fully-grown, non-feeding adult. As non-feeding adults, the energy balance of the pupae must be adequate, to ensure enough energy reserves for adult dispersal, egg maturation and overall persistence of the species in the region. At this stage, environmental temperature also determines daily metabolic demands, and the overall cost of sustaining ecologically relevant activities. Various hypotheses describing a mismatched growth and metabolic …


Seasonal Temperature Changes In Three Midwestern Wastewater Streams And The Effects On Fish Assemblages And Physiology, Ryan William Sparks Jan 2020

Seasonal Temperature Changes In Three Midwestern Wastewater Streams And The Effects On Fish Assemblages And Physiology, Ryan William Sparks

Masters Theses

Midwestern United States undergo extreme temperature and precipitation fluctuations throughout the year, which leads to changing habitats within Illinois river systems. Wastewater treatment facilities have long been used to treat sewage and reduce the organic products in sewage before releasing it into aquatic environments. Wastewater treatment facilities must maintain optimal conditions, especially temperature, for reproduction and growth of facilitated bacteria that break down organic materials in wastewater. The objectives for this study were to determine the thermal effects of wastewater treatment facilities on receiving waters; and secondly, to investigate the influence of these wastewater facilities on fish abundance and assemblages. …


Pioglitazone, Neet Family Proteins, And Galactose Modulation Of Liver Cell Bioenergetics, David F. Grimm Jan 2017

Pioglitazone, Neet Family Proteins, And Galactose Modulation Of Liver Cell Bioenergetics, David F. Grimm

Undergraduate Honors Theses

MitoNEET was discovered through interactions with a labeled and photoactive derivative of pioglitazone (pio), a drug used to increase peripheral insulin sensitivity. Its unique coordination of a [2Fe-2S] cluster by three cysteine residues (Cys-72, Cys-74, and Cys-83) and one histidine (His-87) gives this cluster both stability and the ability to be donated to acceptor proteins. These qualities allow mitoNEET to participate in a diversity of biological functions. Functions of mitoNEET and the consequences of pioglitazone (pio) treatment in human hepatocellular carcinoma (HepG2) cells cultured in glucose or galactose-based medium were examined by respiration and proliferation studies. Pio treatment decreased complex …


The Role Of Creg1 As A Master Regulator Of Liver Function, Abdulrahman Siran Aldaghmi Jan 2017

The Role Of Creg1 As A Master Regulator Of Liver Function, Abdulrahman Siran Aldaghmi

Masters Theses

The liver is known as the chemical factory of the body because it performs a wide range of biochemical functions required for life. Since the liver has such an important role in regulation of normal physiological processes, liver diseases cause a high rate of morbidity and mortality. Therefore, understanding the mechanisms of liver development will shed light on the causes of liver disease. In this study, a cell line model that utilizes rat hepatoma cells (Fg14) and hepatoma variant cells (H11) was used to identify master regulators of liver gene expression. Whole genome expression studies identified the gene CREG1 (Cellular …


Metabolic And Morphologic Shifts In Neuro2a Cells Cultured In Galactose Medium, Leah Welker Jan 2017

Metabolic And Morphologic Shifts In Neuro2a Cells Cultured In Galactose Medium, Leah Welker

Masters Theses

It has been observed that highly-proliferating cells, such as cancer cells, rely mainly on glycolysis for ATP production, regardless of presence of oxygen. This effect, however, can be reversed by changing the main energy substrate in the medium from glucose to galactose. The oxidation of galactose in glycolysis yields less net ATP, presumably forcing the cell into OXPHOS. This has been established in many cell lines, including HeLA, HepG2, and skeletal muscle cells. As of yet, this has not been reproduced in neuronal cells. Using Neuro2a, a murine neuroblastoma cell line, this study exposes neuronal cells to galactose medium, and …


Acute Toxicity Assessment Of N,N-Diethyl-M-Toluamide (Deet) On The Photosynthetic Activity Of The Dinoflagellate Gymnodinium Instriatum, Eloy Martinez, Sylvia Velez, Marietta Mayo, Miguel Sastre Jan 2015

Acute Toxicity Assessment Of N,N-Diethyl-M-Toluamide (Deet) On The Photosynthetic Activity Of The Dinoflagellate Gymnodinium Instriatum, Eloy Martinez, Sylvia Velez, Marietta Mayo, Miguel Sastre

Faculty Research & Creative Activity

Despite the ubiquitous occurrence of N, N-diethyl-m-toluamide (DEET) in aquatic systems, assessments evaluating the toxicity of DEET on phytoplankton species are summed to a single study on a unicellular green alga. In particular, the toxicological effects of DEET in dinoflagellates are unknown. In this study, we employed the mixotrophic dinoflagellate Gymnodinium instriatum as a study system to evaluate acute effects of DEET on the oxygen flux of laboratory cultures. This study reports an inhibitory reaction model of DEET described by the equation y = 4.99 x 0.54, where y represents the percent inhibition of oxygen flux and x represents DEET …


Physiological Performance Of Warm-Adapted Marine Ectotherms: Thermal Limits Of Mitochondrial Energy Transduction Efficiency, Eloy Martinez, Eric Hendricks, Michael Menze, Joseph Torres Jan 2015

Physiological Performance Of Warm-Adapted Marine Ectotherms: Thermal Limits Of Mitochondrial Energy Transduction Efficiency, Eloy Martinez, Eric Hendricks, Michael Menze, Joseph Torres

Faculty Research & Creative Activity

Thermal regimes in aquatic systems have profound implications for the physiology of ectotherms. In particular, the effect of elevated temperatures on mitochondrial energy transduction (i.e. energy from carbon substrates to ATP) in tropical and subtropical teleosts may have profound consequences on organismal performance and population viability. Upper and lower whole-organism critical temperatures for teleosts suggest that subtropical and tropical species are not susceptible to the warming trends associated with climate change, but sub-lethal effects on energy transduction efficiency and population dynamics remain unclear. The goal of the present study was to compare the thermal sensitivity of processes associated with mitochondrial …


D-Galactose Decreases Mitoneet Levels In Liver Cancer Cells: Impact On Cellular Bioenergetics, Sudip Paudel Jan 2015

D-Galactose Decreases Mitoneet Levels In Liver Cancer Cells: Impact On Cellular Bioenergetics, Sudip Paudel

Masters Theses

Galactose is a simple sugar that at supraphysiological concentrations accelerates aging and age-related complications, which lead to impaired mitochondrial functions. MitoNEET is a small mitochondrial membrane protein with a molecular mass of 12.2 kDa that functions in diabetes, iron metabolism, regulation of oxidative phosphorylation (OXPHOS) and reactive oxygen species (ROS) homeostasis. MitoNEET knockdown increases cellular respiration rates and ROS levels similar to galactose treatment. Pioglitazone, an antidiabetic drug, binds to mitoNEET and ameliorates galactose toxicity. Cellular mitoNEET levels, exposure of cells to galactose medium, and pioglitazone treatment directly influence cellular respiration. To elucidate the role of mitoNEET in galactose induced …


Cryopreservation Of Hepatocyte (Hepg2) Cell Monolayers: Impact Of Trehalose, Blake Stokich, Quinn Osgood, David Grimm, Shhyam Moorthy, Nilay Chakraborty, Michael A. Menze Aug 2014

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 …


Mitoneet: Reduction In Insulin Resistance Through Ameliorated Oxidative Stress?, Nicolas A. Ferry May 2014

Mitoneet: Reduction In Insulin Resistance Through Ameliorated Oxidative Stress?, Nicolas A. Ferry

Undergraduate Honors Theses

MitoNEET is a mitochondrial iron-sulfur protein with poorly-understood functions. Proposed functions of mitoNEET include regulating of oxidative capacity, reactive oxygen homeostasis, and other possible roles. Investigating the interactions of mitoNEET with other proteins might help identify functional roles of this protein. MitoNEET was discovered in 2004 to identify physiological targets of pioglitazone hydrochloride, a drug that is commonly used to treat type-2 diabetes. Type-2 diabetes is a metabolic disease and, although the exact pathology is complex, the role of the mitochondrion in cellular energy production and glucose oxidation indicates that this organelle has a role in type-2 diabetes. Because of …


Improved Tolerance To Salt And Water Stress In Drosophila Melanogaster Cells Conferred By Late Embryogenesis Abundant Protein, Matthew R. Marunde, Dilini A. Samarajeewa, John Anderson, Shumin Li, Steven C. Hand, Michael A. Menze Jan 2013

Improved Tolerance To Salt And Water Stress In Drosophila Melanogaster Cells Conferred By Late Embryogenesis Abundant Protein, Matthew R. Marunde, Dilini A. Samarajeewa, John Anderson, Shumin Li, Steven C. Hand, Michael A. Menze

Faculty Research & Creative Activity

Mechanisms that govern anhydrobiosis involve the accumulation of highly hydrophilic macromolecules, such as late embryogenesis abundant (LEA) proteins. Group 1 LEA proteins comprised of 181 (AfLEA1.1) and 197 (AfLEA1.3) amino acids were cloned from embryos of Artemia franciscana and expressed in Drosophila melanogaster cells (Kc167). Confocal microscopy revealed a construct composed of green fluorescence protein (GFP) and AfLEA1.3 accumulates in the mitochondria (AfLEA1.3-GFP), while AfLEA1.1-GFP was found in the cytoplasm. In the presence of mixed substrates, oxygen consumption was statistically identical for permeabilized Kc167 control and Kc167-AfLEA1.3 cells. Acute titrations of permeabilized cells with NaCl up to 500 mM led …


Diapause And Anhydrobiosis In Embryos Of Artemia Franciscana: Metabolic Depression, Lea Proteins And Water Stress, Steven C. Handel, Yuvraj Patil, Shumin Li, Nilay Chakraborty, Apurva Borcar, Michael A. Menze, Leaf C. Boswell, Daniel Moore, Mehmet Toner Jan 2013

Diapause And Anhydrobiosis In Embryos Of Artemia Franciscana: Metabolic Depression, Lea Proteins And Water Stress, Steven C. Handel, Yuvraj Patil, Shumin Li, Nilay Chakraborty, Apurva Borcar, Michael A. Menze, Leaf C. Boswell, Daniel Moore, Mehmet Toner

Faculty Research & Creative Activity

Metabolic depression is typically correlated with extended survival of environmental challenge and energy-limitation in early life stages of various invertebrates and vertebrates. Diapause is an ontogenetically-programmed reduction of development and often metabolism seen in many invertebrates. When embryos of Artemia franciscana enter the state of diapause, the overall metabolic depression is estimated to be greater than 99%. These embryos also contain trehalose and express multiple isoforms of Late Embryogenesis Abundant (LEA) proteins, constituents often present in a number of such anhydrobiotic animals. The mRNA levels for LEA proteins are highest in diapause and post-diapause embryos that possess desiccation tolerance, but …


Late Embryogenesis Abundant Proteins Protect Human Hepatoma Cells During Acute Desiccation, Shumin Li, Nilay Chakraborty, Apurva Borcar, Michael A. Menze, Mehmet Toner, Steven C. Hand Nov 2012

Late Embryogenesis Abundant Proteins Protect Human Hepatoma Cells During Acute Desiccation, Shumin Li, Nilay Chakraborty, Apurva Borcar, Michael A. Menze, Mehmet Toner, Steven C. Hand

Faculty Research & Creative Activity

Expression of late embryogenesis abundant (LEA) proteins is highly correlated with desiccation tolerance in anhydrobiotic animals, selected land plants, and bacteria. Genes encoding two LEA proteins, one localized to the cytoplasm/nucleus (AfrLEA2) and one targeted to mitochondria (AfrLEA3m), were stably transfected into human HepG2 cells. A trehalose transporterwas used for intracellular loading of this disaccharide. Cellswere rapidly and uniformly desiccated to low water content (<0.12 g H2O/g dry weight) with a recently developed spin-drying technique. Immediately on rehydration, control cells without LEA proteins or trehalose exhibited 0% membrane integrity, comparedwith 98% in cells loaded with trehalose and expressing AfrLEA2 or AfrLEA3m; surprisingly, AfrLEA3m without trehalose conferred 94% protection. Cell proliferation across 7 d showed an 18-fold increase for cells dried with AfrLEA3m and trehalose, compared with 27-fold for nondried controls. LEA proteins dramatically enhance desiccation tolerance in mammalian cells and offer the opportunity for engineering biostability in the dried state.


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 Nov 2012

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 …


Long-Term Survival Of Anoxia Despite Rapid Atp Decline In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Jason E. Podrabsky, Michael A. Menze, Steven C. Hand Aug 2012

Long-Term Survival Of Anoxia Despite Rapid Atp Decline In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Jason E. Podrabsky, Michael A. Menze, Steven C. Hand

Faculty Research & Creative Activity

Embryos of the annual killifish Austrofundulus limnaeus can survive for months in the complete absence of oxygen. Survival of anoxia is associated with entry into a state of metabolic dormancy known as diapause. However, extreme tolerance of anoxia is retained for several days of post-diapause development. Rates of heat dissipation in diapause II and 4 days post-diapause II embryos were measured under aerobic conditions and during the transition into anoxia. Phosphorylated adenylate compounds were quantified in embryos during entry into anoxia and after 12 hr of aerobic recovery. Rates of heat dissipation were not affected by exposure to anoxia in …


The Effect Of Ergosterol On The Desaturation Of 14c-Labeled Oleic Acid In Tetrahymena, Maynard E. Neville Jr. Jan 1977

The Effect Of Ergosterol On The Desaturation Of 14c-Labeled Oleic Acid In Tetrahymena, Maynard E. Neville Jr.

Masters Theses

The ciliated protozoan Tetrahymena pyriformis-Strain W desaturated 14C-labeled fatty acid substrate in both sterol supplemented (ergosterol) and nonsupplemented cultures. Cis-octadecenoic acid (14C-9-18:1), when added to the medium during the log phase of growth, was incorporated into the cells and also desaturated at the Δ6 and Δ12 positions. The 14C labeled substrate and products, linoleate (9,12-18:2) or linolenate (6,9,12-18:3) were recovered and separated by silver-nitrate Unisil column chromatography. Initially, recovery of 14C compounds varied widely when expressed as the percent of total counts per minute recovered from column chromotography, and a variety of …