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Jon P. Costanzo - One of the best experts on this subject based on the ideXlab platform.
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Seasonal variation and freezing response of Glucose Transporter 2 in liver of the wood frog: implications for geographic variation in freeze tolerance
Journal of Zoology, 2015Co-Authors: Andrew J Rosendale, Richard E. Lee, Jon P. CostanzoAbstract:Subarctic populations of the wood frog Rana sylvatica survive freezing to temperatures at least 10–13°C below those of more southerly conspecifics. This profound freeze tolerance is due in part to an enhanced glucosic cryoprotectant system that requires rapid mobilization of Glucose from hepatocytes during the early hours of freezing. To determine if Glucose Transporter 2 (GLUT2) in the liver contributes to geographic variation in freeze tolerance, we examined changes in the protein’s abundance seasonally and in response to experimental freezing in frogs from Interior Alaska and southern Ohio, USA. Using immunoblotting techniques, we found that GLUT2 abundance increased in preparation for winter in both populations, but tests with Ohioan frogs showed that that altered temperature alone does not cause these seasonal changes. In Ohioan frogs, Transporter expression apparently was regulated transcriptionally, as mRNA levels, assessed using quantitative real-time polymerase chain reaction, changed in accordance with protein abundance. However, this pattern was not observed in Alaskan frogs, suggesting that other mechanisms of regulation are important in this phenotype. Overall, GLUT2 abundance was constitutively greater and more responsive to freezing in Alaskan R. sylvatica, suggesting that GLUT2 contributes substantively to the extreme freeze tolerance of subarctic wood frogs.
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effect of physiological stress on expression of Glucose Transporter 2 in liver of the wood frog rana sylvatica
Journal of Experimental Zoology, 2014Co-Authors: Andrew J Rosendale, Jon P. CostanzoAbstract:Glucose Transporters (GLUTs) have been implicated in the survival of various physiological stresses in mammals; however, little is known about the role of these proteins in stress tolerance in lower vertebrates. The wood frog (Rana sylvatica), which survives multiple winter-related stresses by copiously mobilizing hepatic glycogen stores, is an interesting subject for the study of Glucose transport in amphibians. We examined the effects of several physiological stresses on GLUT2 protein and mRNA levels in the liver of R. sylvatica. Using immunoblotting techniques to measure relative GLUT2 abundance, we found that GLUT2 numbers increased in response to organismal freezing, hypoxia exposure, and Glucose loading; whereas, experimental dehydration and urea loadingdidnotaffectGLUT2abundance.GLUT2mRNAlevels,assessedusingquantitativereal-time polymerase chain reaction, changed in accordance with protein abundance for most stresses, indicating that transcriptional regulation of GLUT2 occurs in response to stress. Overall, hepatic GLUT2 seems to be important in stress survival in R. sylvatica and is regulated to meet the physiological need to accumulate Glucose. J. Exp. Zool. 321A:566-576, 2014. © 2014 Wiley Periodicals, Inc. Howtocitethisarticle: RosendaleAJ,LeeRE,CostanzoJP.2014.Effectofphysiological stresson expression of Glucose Transporter 2 in liver of the wood frog, Rana sylvatica. J. Exp. Zool. 321A:566-576.
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Cloning, characterization, and expression of Glucose Transporter 2 in the freeze-tolerant wood frog, Rana sylvatica
Biochimica et biophysica acta, 2013Co-Authors: Andrew J Rosendale, Benjamin N. Philip, Richard E. Lee, Jon P. CostanzoAbstract:Abstract Background The essential role of Glucose Transporter 2 (GLUT2) in Glucose homeostasis has been extensively studied in mammals; however, little is known about this important protein in lower vertebrates. The freeze-tolerant wood frog (Rana sylvatica), which copiously mobilizes Glucose in response to freezing, represents an excellent system for the study of Glucose transport in amphibians. Methods GLUT2 was sequenced from northern and southern phenotypes of R. sylvatica, as well as the freeze-intolerant Rana pipiens. These proteins were expressed and functionally characterized in Xenopus oocytes. Abundance of GLUT2 in tissues was analyzed using immunoblotting techniques. Results GLUT2s cloned from these anurans encoded proteins with high sequence homologies to known vertebrate GLUT2s and had similar transport properties, although, notably, transport of the Glucose analog 3-O-methyl- d -Glucose (3-OMG) was strongly inhibited by 150 mM urea. Proteins from all study subjects had similar affinity constants (~ 12 mM) and other kinetic properties; however, GLUT2 abundance in liver was 3.5-fold greater in northern R. sylvatica than in the southern conspecific and R. pipiens. Conclusion Our results indicate that amphibian GLUT2s are structurally and functionally similar to their homologs in other vertebrates, attesting to the conserved nature of this transport protein. The greater abundance of this protein in the northern phenotype of R. sylvatica suggests that these Transporters contribute importantly to freezing survival. General significance This study provides the first functional characterization of any GLUT isoform from an anuran amphibian and novel insights into the role of these proteins in Glucose homeostasis and cryoprotectant mobilization in freeze-tolerant vertebrates.
Andrew J Rosendale - One of the best experts on this subject based on the ideXlab platform.
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Seasonal variation and freezing response of Glucose Transporter 2 in liver of the wood frog: implications for geographic variation in freeze tolerance
Journal of Zoology, 2015Co-Authors: Andrew J Rosendale, Richard E. Lee, Jon P. CostanzoAbstract:Subarctic populations of the wood frog Rana sylvatica survive freezing to temperatures at least 10–13°C below those of more southerly conspecifics. This profound freeze tolerance is due in part to an enhanced glucosic cryoprotectant system that requires rapid mobilization of Glucose from hepatocytes during the early hours of freezing. To determine if Glucose Transporter 2 (GLUT2) in the liver contributes to geographic variation in freeze tolerance, we examined changes in the protein’s abundance seasonally and in response to experimental freezing in frogs from Interior Alaska and southern Ohio, USA. Using immunoblotting techniques, we found that GLUT2 abundance increased in preparation for winter in both populations, but tests with Ohioan frogs showed that that altered temperature alone does not cause these seasonal changes. In Ohioan frogs, Transporter expression apparently was regulated transcriptionally, as mRNA levels, assessed using quantitative real-time polymerase chain reaction, changed in accordance with protein abundance. However, this pattern was not observed in Alaskan frogs, suggesting that other mechanisms of regulation are important in this phenotype. Overall, GLUT2 abundance was constitutively greater and more responsive to freezing in Alaskan R. sylvatica, suggesting that GLUT2 contributes substantively to the extreme freeze tolerance of subarctic wood frogs.
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effect of physiological stress on expression of Glucose Transporter 2 in liver of the wood frog rana sylvatica
Journal of Experimental Zoology, 2014Co-Authors: Andrew J Rosendale, Jon P. CostanzoAbstract:Glucose Transporters (GLUTs) have been implicated in the survival of various physiological stresses in mammals; however, little is known about the role of these proteins in stress tolerance in lower vertebrates. The wood frog (Rana sylvatica), which survives multiple winter-related stresses by copiously mobilizing hepatic glycogen stores, is an interesting subject for the study of Glucose transport in amphibians. We examined the effects of several physiological stresses on GLUT2 protein and mRNA levels in the liver of R. sylvatica. Using immunoblotting techniques to measure relative GLUT2 abundance, we found that GLUT2 numbers increased in response to organismal freezing, hypoxia exposure, and Glucose loading; whereas, experimental dehydration and urea loadingdidnotaffectGLUT2abundance.GLUT2mRNAlevels,assessedusingquantitativereal-time polymerase chain reaction, changed in accordance with protein abundance for most stresses, indicating that transcriptional regulation of GLUT2 occurs in response to stress. Overall, hepatic GLUT2 seems to be important in stress survival in R. sylvatica and is regulated to meet the physiological need to accumulate Glucose. J. Exp. Zool. 321A:566-576, 2014. © 2014 Wiley Periodicals, Inc. Howtocitethisarticle: RosendaleAJ,LeeRE,CostanzoJP.2014.Effectofphysiological stresson expression of Glucose Transporter 2 in liver of the wood frog, Rana sylvatica. J. Exp. Zool. 321A:566-576.
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Characterization and physiological regulation of Glucose Transporter 2 in the liver of the wood frog, Rana sylvatica: Implications for freeze tolerance
2014Co-Authors: Andrew J RosendaleAbstract:CHARACTERIZATION AND PHYSIOLOGICAL REGULATION OF Glucose Transporter 2 IN THE LIVER OF THE WOOD FROG, RANA SYLVATICA: IMPLICATIONS FOR FREEZE TOLERANCE by Andrew J. Rosendale Winter presents organisms inhabiting temperate regions with various stresses, including low temperature. To contend with subzero temperatures, a small group of ectotherms tolerate freezing, in part through the use of cryoprotective solutes. In the wood frog, Rana sylvatica, Glucose serves an important role in freezing survival; however, the mechanisms underlying the transport and distribution of cryoprotectants such as Glucose are not fully understood. This dissertation describes several studies that examined a Glucose transport protein (GLUT2) and its importance in the freeze tolerance of R. sylvatica. First, I identified and functionally characterized a GLUT2 homolog from R. sylvatica to understand its role in Glucose homeostasis. The newly identified GLUT2 was structurally and phylogenetically similar to other known GLUT2s. Measurements of transport kinetics in Xenopus oocytes determined that GLUT2 from R. sylvatica is functionally similar to previously characterized GLUT2s. This protein was found in various tissues but was most abundant in liver. Finally, transport kinetics were similar among two populations of R. sylvatica, and R. pipiens; however, GLUT2 abundance was greatest in the northern R. sylvatica. R. sylvatica relies on Glucose to survive multiple winter-related stresses, and the second study examined regulation of GLUT2 in response to these stresses. GLUT2 expression increased in response to organismal freezing, hypoxia exposure, and Glucose loading; whereas, experimental dehydration and urea loading had no effect. These changes were the result of transcriptional regulation, resulting in synthesis of new protein. Results of this study suggest that hepatic GLUT2 is regulated to meet the physiological need to accumulate Glucose. Subarctic populations of R. sylvatica survive freezing to lower temperatures than conspecifics from temperate regions. In the last study, I sought to determine if GLUT2 contributes to the profound freeze tolerance of northern frogs. We examined GLUT2 expression in R. sylvatica from Interior Alaska and Ohio and found that GLUT2 abundance increased in preparation for winter in both populations, but that GLUT2 abundance was greater in Alaskan frogs. In Alaskan, but not Ohioan, frogs, GLUT2 protein increased in response to experimental freezing. These results suggest that GLUT2 is important in the extreme freeze tolerance of northern wood frogs. CHARACTERIZATION AND PHYSIOLOGICAL REGULATION OF Glucose Transporter 2 IN THE LIVER OF THE WOOD FROG, RANA SYLVATICA: IMPLICATIONS FOR FREEZE TOLERANCE
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Cloning, characterization, and expression of Glucose Transporter 2 in the freeze-tolerant wood frog, Rana sylvatica
Biochimica et biophysica acta, 2013Co-Authors: Andrew J Rosendale, Benjamin N. Philip, Richard E. Lee, Jon P. CostanzoAbstract:Abstract Background The essential role of Glucose Transporter 2 (GLUT2) in Glucose homeostasis has been extensively studied in mammals; however, little is known about this important protein in lower vertebrates. The freeze-tolerant wood frog (Rana sylvatica), which copiously mobilizes Glucose in response to freezing, represents an excellent system for the study of Glucose transport in amphibians. Methods GLUT2 was sequenced from northern and southern phenotypes of R. sylvatica, as well as the freeze-intolerant Rana pipiens. These proteins were expressed and functionally characterized in Xenopus oocytes. Abundance of GLUT2 in tissues was analyzed using immunoblotting techniques. Results GLUT2s cloned from these anurans encoded proteins with high sequence homologies to known vertebrate GLUT2s and had similar transport properties, although, notably, transport of the Glucose analog 3-O-methyl- d -Glucose (3-OMG) was strongly inhibited by 150 mM urea. Proteins from all study subjects had similar affinity constants (~ 12 mM) and other kinetic properties; however, GLUT2 abundance in liver was 3.5-fold greater in northern R. sylvatica than in the southern conspecific and R. pipiens. Conclusion Our results indicate that amphibian GLUT2s are structurally and functionally similar to their homologs in other vertebrates, attesting to the conserved nature of this transport protein. The greater abundance of this protein in the northern phenotype of R. sylvatica suggests that these Transporters contribute importantly to freezing survival. General significance This study provides the first functional characterization of any GLUT isoform from an anuran amphibian and novel insights into the role of these proteins in Glucose homeostasis and cryoprotectant mobilization in freeze-tolerant vertebrates.
Richard E. Lee - One of the best experts on this subject based on the ideXlab platform.
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Seasonal variation and freezing response of Glucose Transporter 2 in liver of the wood frog: implications for geographic variation in freeze tolerance
Journal of Zoology, 2015Co-Authors: Andrew J Rosendale, Richard E. Lee, Jon P. CostanzoAbstract:Subarctic populations of the wood frog Rana sylvatica survive freezing to temperatures at least 10–13°C below those of more southerly conspecifics. This profound freeze tolerance is due in part to an enhanced glucosic cryoprotectant system that requires rapid mobilization of Glucose from hepatocytes during the early hours of freezing. To determine if Glucose Transporter 2 (GLUT2) in the liver contributes to geographic variation in freeze tolerance, we examined changes in the protein’s abundance seasonally and in response to experimental freezing in frogs from Interior Alaska and southern Ohio, USA. Using immunoblotting techniques, we found that GLUT2 abundance increased in preparation for winter in both populations, but tests with Ohioan frogs showed that that altered temperature alone does not cause these seasonal changes. In Ohioan frogs, Transporter expression apparently was regulated transcriptionally, as mRNA levels, assessed using quantitative real-time polymerase chain reaction, changed in accordance with protein abundance. However, this pattern was not observed in Alaskan frogs, suggesting that other mechanisms of regulation are important in this phenotype. Overall, GLUT2 abundance was constitutively greater and more responsive to freezing in Alaskan R. sylvatica, suggesting that GLUT2 contributes substantively to the extreme freeze tolerance of subarctic wood frogs.
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Cloning, characterization, and expression of Glucose Transporter 2 in the freeze-tolerant wood frog, Rana sylvatica
Biochimica et biophysica acta, 2013Co-Authors: Andrew J Rosendale, Benjamin N. Philip, Richard E. Lee, Jon P. CostanzoAbstract:Abstract Background The essential role of Glucose Transporter 2 (GLUT2) in Glucose homeostasis has been extensively studied in mammals; however, little is known about this important protein in lower vertebrates. The freeze-tolerant wood frog (Rana sylvatica), which copiously mobilizes Glucose in response to freezing, represents an excellent system for the study of Glucose transport in amphibians. Methods GLUT2 was sequenced from northern and southern phenotypes of R. sylvatica, as well as the freeze-intolerant Rana pipiens. These proteins were expressed and functionally characterized in Xenopus oocytes. Abundance of GLUT2 in tissues was analyzed using immunoblotting techniques. Results GLUT2s cloned from these anurans encoded proteins with high sequence homologies to known vertebrate GLUT2s and had similar transport properties, although, notably, transport of the Glucose analog 3-O-methyl- d -Glucose (3-OMG) was strongly inhibited by 150 mM urea. Proteins from all study subjects had similar affinity constants (~ 12 mM) and other kinetic properties; however, GLUT2 abundance in liver was 3.5-fold greater in northern R. sylvatica than in the southern conspecific and R. pipiens. Conclusion Our results indicate that amphibian GLUT2s are structurally and functionally similar to their homologs in other vertebrates, attesting to the conserved nature of this transport protein. The greater abundance of this protein in the northern phenotype of R. sylvatica suggests that these Transporters contribute importantly to freezing survival. General significance This study provides the first functional characterization of any GLUT isoform from an anuran amphibian and novel insights into the role of these proteins in Glucose homeostasis and cryoprotectant mobilization in freeze-tolerant vertebrates.
Sean T Bailey - One of the best experts on this subject based on the ideXlab platform.
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sodium Glucose Transporter 2 is a diagnostic and therapeutic target for early stage lung adenocarcinoma
Science Translational Medicine, 2018Co-Authors: Claudio Scafoglio, Brendon Villegas, Gihad Abdelhady, Sean T Bailey, Aditya S Shirali, Dean W Wallace, Clara E Magyar, Tristan Grogan, David ElashoffAbstract:The diagnostic definition of indeterminate lung nodules as malignant or benign poses a major challenge for clinicians. We discovered a potential marker, the sodium-dependent Glucose Transporter 2 (SGLT2), whose activity identified metabolically active lung premalignancy and early-stage lung adenocarcinoma (LADC). We found that SGLT2 is expressed early in lung tumorigenesis and is found specifically in premalignant lesions and well-differentiated adenocarcinomas. SGLT2 activity could be detected in vivo by positron emission tomography (PET) with the tracer methyl 4-deoxy-4-[18F] fluoro-alpha-d-glucopyranoside (Me4FDG), which specifically detects SGLT activity. Using a combination of immunohistochemistry and Me4FDG PET, we identified high expression and functional activity of SGLT2 in lung premalignancy and early-stage/low-grade LADC. Furthermore, selective targeting of SGLT2 with FDA-approved small-molecule inhibitors, the gliflozins, greatly reduced tumor growth and prolonged survival in autochthonous mouse models and patient-derived xenografts of LADC. Targeting SGLT2 in lung tumors may intercept lung cancer progression at early stages of development by pairing Me4FDG PET imaging with therapy using SGLT2 inhibitors.
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Abstract A16: Sodium-dependent Glucose Transporter 2 is a novel diagnostic and therapeutic target for early-stage lung adenocarcinoma
Early Detection and Prevention, 2018Co-Authors: Claudio Scafoglio, Gihad Abdelhady, Sean T Bailey, Aditya S Shirali, Dean W Wallace, Jie Liu, Jane Yanagawa, Jorge R. Barrio, Ernest M. Wright, Tonya C. WalserAbstract:Lung cancer claims approximately 160,000 lives in the United States every year, and lung adenocarcinoma (LADC) is the most frequent type. Early diagnosis is crucial; the National Lung Screening Trial showed a 20% reduction in mortality in high-risk individuals screened by computed tomography (CT). However, CT has low specificity in early-stage LADC. In vivo detection of Glucose uptake by FDG PET is a standard tool for lung cancer staging, but has low sensitivity in early-stage LADC. Here, we demonstrate that GLUT Transporters, responsible for FDG uptake, are expressed in advanced, poorly differentiated LADC, whereas early LADC utilizes a different Glucose transport system, the sodium-dependent Glucose Transporter 2 (SGLT2), that is not detected by FDG. This can be imaged with the novel tracer Me4FDG. We investigated the expression of two different Glucose Transporters, GLUT1 and SGLT2, in a cohort of 56 human LADC specimens, in patient-derived xenografts, and in a KrasG12D-driven, p53-null genetically engineered mouse model of LADC. We observed a switch in the modality of Glucose transport during lung carcinogenesis: SGLT2 was highly expressed in premalignant lesions and well-differentiated LADC, whereas GLUT1 was upregulated in advanced, poorly differentiated lesions. This pattern was observed both in human samples and in murine models. This observation led us to hypothesize that early-stage LADCs are often negative on FDG PET because this imaging modality does not detect the activity of SGLT2, which is expressed in early lesions. Therefore, we performed PET imaging with the tracer Me4FDG, which measures SGLT2 activity, in our mouse model, and observed that Me4FDG accumulated in small nodules that were negative with FDG. We confirmed the functionality of SGLT2 in human LADC by Me4FDG PET in patient-derived xenografts. Finally, we tested the hypothesis that sodium-dependent Glucose transport is a critical metabolic supply strategy in the early stages of lung adenocarcinoma development. We performed therapeutic trials in genetically engineered mouse models with the FDA-approved SGLT2 inhibitor canagliflozin, which slowed down tumor progression and prolonged mouse survival, by specifically reducing the proliferation rate of premalignant lesions. In conclusion, Me4FDG PET is a novel diagnostic test to image lung premalignancy and early-stage LADC. We propose that Me4FDG-PET will identify the patients who are likely to respond to SGLT2 inhibition, as a cancer interception strategy to prevent the progression of premalignancy to invasive disease, by blocking the supply of Glucose required for proliferation of premalignant lesions. Citation Format: Claudio Scafoglio, Sean T. Bailey, Gihad Abdelhady, Jie Liu, Jane Yanagawa, Aditya Shirali, Dean W. Wallace, Jorge R. Barrio, Ernest M. Wright, Tonya Walser, Steven M. Dubinett, David B. Shackelford. Sodium-dependent Glucose Transporter 2 is a novel diagnostic and therapeutic target for early-stage lung adenocarcinoma [abstract]. In: Proceedings of the Fifth AACR-IASLC International Joint Conference: Lung Cancer Translational Science from the Bench to the Clinic; Jan 8-11, 2018; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(17_Suppl):Abstract nr A16.
David Elashoff - One of the best experts on this subject based on the ideXlab platform.
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sodium Glucose Transporter 2 is a diagnostic and therapeutic target for early stage lung adenocarcinoma
Science Translational Medicine, 2018Co-Authors: Claudio Scafoglio, Brendon Villegas, Gihad Abdelhady, Sean T Bailey, Aditya S Shirali, Dean W Wallace, Clara E Magyar, Tristan Grogan, David ElashoffAbstract:The diagnostic definition of indeterminate lung nodules as malignant or benign poses a major challenge for clinicians. We discovered a potential marker, the sodium-dependent Glucose Transporter 2 (SGLT2), whose activity identified metabolically active lung premalignancy and early-stage lung adenocarcinoma (LADC). We found that SGLT2 is expressed early in lung tumorigenesis and is found specifically in premalignant lesions and well-differentiated adenocarcinomas. SGLT2 activity could be detected in vivo by positron emission tomography (PET) with the tracer methyl 4-deoxy-4-[18F] fluoro-alpha-d-glucopyranoside (Me4FDG), which specifically detects SGLT activity. Using a combination of immunohistochemistry and Me4FDG PET, we identified high expression and functional activity of SGLT2 in lung premalignancy and early-stage/low-grade LADC. Furthermore, selective targeting of SGLT2 with FDA-approved small-molecule inhibitors, the gliflozins, greatly reduced tumor growth and prolonged survival in autochthonous mouse models and patient-derived xenografts of LADC. Targeting SGLT2 in lung tumors may intercept lung cancer progression at early stages of development by pairing Me4FDG PET imaging with therapy using SGLT2 inhibitors.