bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification and Characterization of FGGY Carbohydrate Kinase Domain Containing (Fggy) in Skeletal Muscle
Authors: Novo Karla , Waddell David 
Published: June 2021

Skeletal muscle atrophy can result from a range of physiological conditions, including denervation, corticosteroid exposure, immobilization and aging. In order to better characterize the molecular genetic events of atrophy, skeletal muscle was isolated from mice following 3 days and 14 days of denervation. The gene expression profile of the denervated muscle tissue was analyzed by microarray and compared to control muscle in order to identify novel atrophy‐induced genes. The microarray revealed that FGGY carbohydrate kinase domain containing (Fggy) is expressed in skeletal muscle and is induced in response to denervation. Bioinformatic analysis of the Fggy gene locus revealed two validated alternative isoforms, which we have termed Fggy‐001 and Fggy‐003, that have distinct transcription initiation sites. In order to confirm that Fggy is expressed in muscle cells, the cDNAs of the two validated alternative splice variants were cloned from mouse myoblast cells. Interestingly, a novel alternative spice variant for each of the validated alternative isoforms was also cloned from mouse muscle cells, suggesting that at least four Fggy variants are expressed in skeletal muscle. In order to better characterize the expression profile of the Fggy gene, quantitative RT‐PCR (RT‐qPCR) was performed using RNA isolated from muscle cells and primer pairs that distinguish the four alternative Fggy transcripts. The RT‐qPCR data reveals that the Fggy‐001 transcripts are more highly expressed in proliferating muscle cells, while the Fggy‐003 transcripts are more evenly expressed in muscle cells that are both proliferating and differentiated. Western Blot analysis of protein homogenates isolated from muscle cells confirmed that the Fggy‐001 isoform is more highly expressed in proliferating muscle cells, while the Fggy‐003 isoform is more ubiquitously expressed. Finally, confocal fluorescent microscopy analysis revealed that the Fggy‐001 full length transcript is localized throughout the cell, while the Fggy‐001 novel alternative transcript only appears to be localized to the cytoplasm. Moreover, the Fggy‐003 novel alternative transcript produces a punctuate localization pattern throughout the cytoplasm of proliferating muscle cells. The characterization of novel genes that are activated during neurogenic atrophy helps improve our understanding of the molecular and cellular events that lead to muscle atrophy and could eventually lead to new therapeutic targets for the treatment of muscle wasting.Support or Funding InformationThe work was support by University of North Florida Transformational Learning Opportunity grants to D.W.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The role of Nrf2 in exercise training‐mediated regulation of antioxidant enzymes in skeletal muscle
Authors: Okutsu Mitsuharu , Yamada Mami , Iwata Masahiro 
Published: June 2021

Oxidative stress has been implicated in the pathogenesis of skeletal muscle wasting. Regular exercise training prevents oxidative stress‐induced muscle wasting by at least partially improving the antioxidant defense system. However, the underlying molecular mechanisms involved remain elusive. In this study, we assessed whether the nuclear factor erythroid 2‐related factor (Nrf2), the master regulator of antioxidant gene transcription, is essential for the exercise training‐mediated increase in expression of antioxidant enzymes. We performed 3 complementary studies. First, C2C12 myotubes were subjected to 110% cyclic uniaxial stretch for 1 and 6 hours at a frequency of 1 Hz to assess whether stretching regulates mRNA expression of Nrf2. Second, C57BL/6 mice were subjected to either voluntary wheel running for 4 weeks or no exercise to examine whether exercise training regulates Nrf2 and antioxidant enzyme protein expression in muscle. Third, muscle‐specific Nrf2 knockout (Nrf2MKO) and wild‐type littermates (WT) mice were assigned to either exercise training or sedentary groups, and the muscle content of antioxidant enzymes was determined after 4 weeks of exercise training. Our results revealed a significant elevation in Nrf2 mRNA expression in C2C12 myotubes at 6 hours of mechanical stretch. Voluntary running in C57BL/6 mice increased antioxidant enzyme protein (i.e., Cu/ZnSOD, EcSOD) in soleus muscle. Moreover, expression of the Nrf2 target antioxidant gene NQO1 in Nrf2MKO skeletal muscle was abolished compared to WT mice. Loss of Nrf2 in skeletal muscle also blunted the exercise training‐mediated increase in antioxidant enzymes in soleus muscles. These findings indicate that Nrf2 is required for exercise training‐mediated increase of antioxidant enzymes in skeletal muscle.Support or Funding InformationThis study was funded by Grant‐in‐Aid for Challenging Exploratory Research (16K13019) and Grant‐in‐Aid for Scientific Research (B) (15H03080) to M. Okutsu.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
p62/SQSTM1 is required for exercise training‐mediated regulation of antioxidant enzymes in skeletal muscle
Authors: Yamada Mami , Iwata Masahiro , Okutsu Mitsuharu 
Published: June 2021

Oxidative stress has been implicated in the pathogenesis of skeletal muscle wasting. Regular exercise training prevents oxidative stress‐induced muscle wasting at least partially by improving the antioxidant defense system. It has been shown that p62/sequestosome1 (SQSTM1) competitively binds to Keap1 activating the nuclear factor erythroid 2‐related factor 2 (Nrf2), which stimulates transcription of antioxidant enzymes. However, it remains to be determined if this process is active in skeletal muscle. Therefore, this study aims to determine whether p62 is required for the exercise training‐mediated increase in antioxidant enzymes in skeletal muscle. To do so, we used 3 complementary studies: i) C2C12 myotubes were subjected to 110% cyclic uniaxial stretch for 1 and 6 hours at a frequency of 1 Hz to assess whether stretching regulates p62 mRNA expression; ii) C57BL/6 mice were assigned to either voluntary wheel running for 4 weeks or no exercise to examine whether exercise training regulates p62 protein expression and phosphorylation (Ser351), both of which increase p62 affinity for Keap1 binding; and iii) muscle‐specific p62 knockout (p62MKO) and wild‐type littermates (WT) mice were assigned to either exercise training or sedentary groups, and the muscle content of antioxidant enzymes was determined after 4 weeks of exercise training. Our results demonstrated that p62 mRNA levels were significantly increased at 6 hours of mechanical stretch in C2C12 myotubes. Voluntary running in C57BL/6 mice increased p62 protein and p62 phosphorylation in soleus muscle. Moreover, expression of the Nrf2 target antioxidant gene NQO1 in p62MKO skeletal muscle was abolished compared to WT mice. Loss of p62 in skeletal muscle also blunted the exercise training‐mediated increase in antioxidant enzymes (i.e. Cu/ZnSOD, EcSOD) in soleus muscle. These findings indicate that p62 is required for exercise training‐mediated increase of antioxidant enzymes in skeletal muscle likely via modulation of Nrf2 function.Support or Funding InformationThis study was funded by Grant‐in‐Aid for Challenging Exploratory Research (16K13019) and Grant‐in‐Aid for Scientific Research (B) (15H03080) to M. Okutsu.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Mechanisms of neuroprotection against oxidative stress in the anoxia tolerant turtle Trachemys scripta
Authors: Reiterer Melissa , Milton Sarah L. 
Published: June 2021

The detrimental effects of oxidative stress caused by the accumulation of Reactive Oxygen Species (ROS) have been acknowledged as major factors in aging, senescence, and several neurodegenerative conditions including Parkinson's Disease and stroke (ischemia/reperfusion). Mammalian models are extremely susceptible to these stresses and the restoration of oxygen after anoxia causes oxidative damage; however some organisms including the freshwater turtle Trachemys scripta can withstand such conditions without any apparent pathology. T. scripta thus provides us with a model in which we can investigate physiological mechanisms of neuroprotection in anoxia and reoxygenation without the damaging effects that come with oxidative stress.The ability of the turtle to survive these stressors is thought to be related to its high innate levels of antioxidants and its capacity to suppress ROS production. One potential antioxidant mechanism is the Methionine Sulfoxide Reductase System (Msr) that catalyzes the reduction of oxidized Methionine (Met) residues. Methionine residues are easily oxidized amino acids and oxidized Met is associated with decreased protein activity. Msr may also restore function to damaged proteins and it has been shown to scavenge ROS and thus ameliorate cellular damage.The present study investigated the role and regulation of MsrA in turtle primary neuronal cell cultures exposed to 4 hours of anoxia and 4 hours of anoxia followed by 4 hours of reoxygenation. Anoxia and anoxia/reoxygenation increase MsrA mRNA and protein levels, which suggests a protective role under these conditions. MsrA expression was then altered with target specific siRNA; we found that the knock down of MsrA expression resulted in decreased cell viability. As the factors that control MsrA expression in this model are still unknown, we also induced FOXO3a expression by transfecting a FOXO3a plasmid into the cells, as it has been shown to regulate MsrA levels in other animal models. The induction of FOXO3a protected neurons against cell death. Furthermore, treatment of cells with the green tea extract Epigallocatechin gallate (EGCG), which has antioxidant properties, results in increased expression of FOXO3a when the cells are exposed to oxidative stress. Together these results suggest that MsrA may play an important role in protection against anoxia and oxidative stress in the turtle brain, and may prove to be a target to treat diseases of ischemia and oxidative stress.Support or Funding InformationNIH‐NIA Project # 1R15AG033374‐01,FAU FoundationThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Seal Endothelial Cells: a Comparative Model to Study Natural Tolerance to Ischemia/Reperfusion
Authors: Vazquez‐Medina Jose Pablo , Allen Kaitlin , Hindle Allyson G. 
Published: June 2021

Reperfusion injury is a common complication derived from ischemia/reperfusion events that occur in the course of myocardial infarction, stroke, embolism and other peripheral vascular diseases. Lack of blood during ischemic episodes activates cellular pathways that upregulate pro‐inflammatory signaling and increase oxidant generation. Reperfusion after ischemia leads to the recruitment of inflammatory cells further exacerbating oxidant production and ultimately resulting in cell death, tissue injury and organ dysfunction. Seals experience routine, repetitive episodes of peripheral ischemia/reperfusion during and after dives. These ischemia/reperfusion events are a direct consequence of the cardiovascular adjustments that allow seals to maximize the use of their oxygen stores while diving but result in selectively reduced perfusion to peripheral tissues. Remarkably, seals show no apparent detrimental effects associated with these ischemia/reperfusion events. The cellular mechanisms that underlie this natural tolerance to a potentially pathological condition, however, remain unknown. We isolated and cryopreserved primary endothelial cells from Weddell seal placental arteries to study the mechanisms that confer ischemic tolerance to seal cells. Seal endothelial cells were evaluated for dil‐acetylated low‐density lipoprotein (dil‐AcLDL) uptake and immunostained with endothelial markers to confirm the endothelial phenotype of the preparation. Seal cells were also stimulated with phorbol ester to test whether or not they are capable of producing oxidants. Weddell seal endothelial cell monolayers exhibit a cobblestone‐like morphology characteristic of human and murine endothelial cells and stained positive for vascular endothelial cadherin by immunofluorescence. Live seal cells in culture were functionally capable of incorporating labeled dil‐AcLDL and generated hydrogen peroxide in a concentration‐dependent manner when stimulated with phorbol ester. These results suggest that primary seal endothelial cells in culture are a viable, novel and potentially useful model to study cellular mechanisms associated with natural tolerance to ischemia/reperfusion.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Novel Regulators of Epithelial Migration and Differentiation
Authors: Dunnwald Martine 
Published: June 2021

Epithelial migration and differentiation are key cellular processes required for wound closure. We recently identified Interferon Regulatory Factor 6 (IRF6) as a transcription factor that regulates both of these processes. We previously demonstrated that Irf6‐deficient embryos and Irf6‐deficient keratinocytes displayed impaired wound healing and cellular migration. Furthermore, individuals with IRF6 mutations (van der Woude syndrome, the most common form of syndromic orofacial cleft) exhibited increased likelihood of wound healing complications following surgical repair. Therefore, we hypothesized that altered expression of Irf6 and its downstream effectors would lead to impaired wound healing in adults. Using murine models with different Irf6 levels, we showed that reduced levels of Irf6 are more detrimental in early stages of wound healing (day 4) and increased levels are more detrimental in late stages of wound healing (day 7). Furthermore, keratinocytes from syndromic orofacial cleft patients were slower at closing an in vitro scratch compared to non‐syndromic keratinocytes. One of the downstream targets of Irf6 is Arhgap29 (Rho GTPase Activating Protein 29). Arhgap29 is decreased in the absence of Irf6, and could mediate the Irf6‐dependent migration. We are currently testing the role of Arhgap29 in vivo using a novel Arhgap29 allele containing a genetic variant identified in a patient with cleft lip and palate. Together, these results demonstrate that the positive and negative perturbation of the levels of Irf6 lead to defects throughout the entire period of wound healing. Ultimately, these data suggest the existence of a critical therapeutic window for IRF6 that should be considered in designing new clinical treatments for wound healing.Support or Funding InformationNIH/MIAMS AR067739This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Consumption of a Refined Carbohydrate Diet Does Not Impair Vasodilation of Cranial Tibial Arteries in the Mourning Dove, Zenaida macroura
Authors: Clark William , Basile Anthony J. , Deviche Pierre , Sweazea Karen L. 
Published: June 2021

Chronic hyperglycemia in mammals correlates positively with the production of reactive oxygen species (ROS) and is associated with impaired vasodilation. Plasma glucose (Pglu) in birds including Mourning Doves (MODO) is generally higher than in mammals, yet vascular ROS in MODO are similar to levels measured in healthy rodents. This difference may be due to abundant endogenous antioxidants such as uric acid and vitamin C in birds. We hypothesized that feeding doves a refined carbohydrate diet would not impair vasodilation. To examine this, we captured MODO (n = 11) in Tempe, AZ, and housed them for five weeks. Birds were acclimated for one week during which they transitioned either to a nutritionally‐balanced dove seed diet (controls, CONT) or to a refined carbohydrate (WB; white sandwich bread) diet. We collected a blood sample from the brachial vein of each bird upon arrival and at the end of the 4‐week treatment for the measurement of serum metabolites. At the end of the study, we euthanized birds and cranial tibial arteries were isolated, cannulated with glass pipettes, and pressurized in a vessel chamber. Isolated arteries were pre‐constricted to 50% of the initial diameter by adding increasing doses of phenylephrine to the superfusate. We then measured vasodilation by adding increasing doses of the endothelium‐dependent vasodilator acetylcholine (10−9 M to 10−5 M). Vasodilation, serum glucose, uric acid, triglycerides, and free glycerol were not significantly different between groups (p>0.05). To examine the effects of captivity, we compared data to those from previous studies on isolated arteries from wild MODO (WILD). Endothelium‐dependent vasodilation was greater in captive than wild doves (CONT vs. WILD, p<0.01; WB vs. WILD, p<0.05). These findings are consistent with our hypothesis as refined carbohydrate consumption did not impair vasodilation. Moreover, captivity improved vasodilation when compared to wild doves regardless of diet type. The findings contrast with those in mammals, in which high carbohydrate consumption results in impaired endothelium‐dependent vasodilation.Support or Funding InformationThis study was funded in part by an IOSP APS summer research fellowship (WC).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hemoglobin In An Ancestral Hibernator, The Common Tenrec, Tenrec ecaudatus
Authors: York Sarah E. , van Breukelen Frank 
Published: June 2021

Common tenrecs, Tenrec ecaudatus, are medium‐sized mammalian tropical hibernators endemic to Madagascar. Tenrecs are capable of effectively hibernating at temperatures between 12 and 28°C and do not undergo periodic arousals during hibernation, a feature common to all other known hibernators. Interestingly, these tenrecs can also experience spontaneous bouts of torpor during the active season known as facultative torpor (FT). During hibernation and FT, oxygen consumption rates are 1.1–14% of active rates depending on ambient temperature. We have observed marked variation in hematocrit (between 15 and 50%). We asked what happens to hemoglobin concentration and type across the annual cycle and state. A colorimetric assay was performed for hemoglobin concentration in whole blood. Isoelectric focusing was used to assay for changes in hemoglobin type (e.g. fetal vs adult types) across the physiological states. These data will serve as an initial step in helping to determine how tenrecs are able to achieve low metabolic rates without concomitant decreases in body temperature.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Immune Function In The Basoendothermic Common Tenrec, Tenrec ecaudatus
Authors: Smith Catlene J. , van Breukelen Frank 
Published: June 2021

Common tenrecs, Tenrec ecaudatus, are small hibernating mammals endemic to Madagascar and demonstrate extreme variability in body temperature and metabolism. When housed at ambient temperatures of 12–28 °C, tenrecs may hibernate or be active with body temperatures of ~13–34 °C depending on ambient temperature. During hibernation, tenrecs are consistently lethargic and do not exhibit the typical euthermic periods of rewarming that other hibernators experience. In classic hibernators, injection of lipopolysaccharide (LPS) during torpor results in an elevated temperature during the subsequent periodic arousal between torpor bouts. In tenrecs, injection of LPS does not result in increased temperature suggesting no immune recognition of LPS. Complement activity in tenrecs will be determined through the ability to lyse foreign red blood cells to determine the status of immune function in various states and as a function of body temperature. These data will help define the immune status across the annual cycle in a mammal with ancestral features.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of Incubation Temperature on Survival, Growth and Oxygen Consumption of Developing Brine shrimp (Artemia franciscana)
Authors: Melendez Christopher L. , Mueller Casey A. 
Published: June 2021

Brine shrimp (Artemia franciscana) are commercially harvested aquatic crustaceans that naturally inhabit inland and costal hypersaline environments. Brine shrimp are highly adaptable to such abiotic environmental fluctuations and exhibit the ability to survive in salinity concentrations ranging from 10–200 parts per thousand (ppt), and water temperatures ranging from 10–35°C. To assess the effect of the environment on development, we examined whether various incubation temperatures (20°C, 25°C and 30°C) directly affect morphological and physiological phenotypes of developing brine shrimp during a 40 day period from hatch to late juvenile/adult stages. Morphology was assessed throughout development using measurements of brine shrimp total body length (top of the median eye to the posterior of the caudal furca) and third appendage length (body's midline to the tip of the third swimming appendage). Developmental instar stage and survival were also recorded. Oxygen consumption rate (Vo2) was used as a functional measure of energy use throughout development. We found survival significantly decreased throughout development (P < 0.001). Survival to 40 days post hatch (dph) was similar at 20°C and 25°C, but no brine shrimp survived at 30°C beyond 30 dph. While a two‐way ANOVA indicated temperature had a significant effect on total body length (P = 0.002) and length of the third appendage (P < 0.001), temperature was not significant when examined on each developmental day. Therefore, the effect of developmental day was examined for all temperatures combined. Both total body length and length of the third appendage displayed trends of increasing length with development for all temperatures combined (P < 0.001 for both). Instar stage significantly increased with developmental day (P < 0.0001), but temperature only had a significant effect on development until 11 dph. The interaction between incubation temperature and developmental day for whole animal Vo2 was not significant (P=0.074), and thus the slope of whole animal Vo2 against developmental day did not differ between temperatures. Mass‐specific Vo2 was also not strongly affected by temperature, but brine shrimp showed a peak in mass‐specific Vo2 around 15 dph. The minimal temperature effect on development, morphology, growth, and Vo2 suggest that developmental brine shrimp metabolically compensate for temperatures within the range of 20–30°C, which likely reflects the variable thermal environment they live in.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.