Sequence and expression analysis of glucokinase mRNA from herbivorous Giant gourami (Osphronemus goramy)

Abstract. Sari DN, Nasrullah H, Ekasari J, Suprayudi MA, Alimuddin A. 2021. Sequence and expression analysis of glucokinase mRNA from herbivorous Giant gourami (Osphronemus goramy). Biodiversitas 22: 741-750. Glucokinase (GCK) is one of the enzymes that play important roles in carbohydrate metabolism and high glucose homeostatic in fish. The information about the GCK mRNA sequence and its expression is limited in Giant gourami, one of the most important herbivorous aquaculture species in Indonesia. The present study aimed to characterize the GCK mRNA and analyze its mRNA expression and plasma glucose levels after high glucose injection in Giant gourami. We also compared its sequence variability among carnivorous and herbivorous fish. The GCK mRNA was identified using polymerase chain reaction (PCR) method from the fish liver. Its mRNA level was analyzed by real-time PCR (qPCR). Giant gourami GCK mRNA sequence was 2104 nucleotide long, encoding 478 amino acids, and shared high similarity with other fish. GCK was mainly expressed in the liver. The mRNA level of GCK was highly up-regulated after 6 hours of high glucose injection, in-line with the plasma glucose in the blood. There are no major differences observed in the GCK amino acid sequences among Giant gourami and other fish. The knowledge gained from this study could be used as a reference for further exploration of metabolic regulation in Giant gourami.

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Glucose regulates expression of pro-inflammatory genes IL-1β and IL-12 through a mechanism involving hexosamine biosynthesis pathway dependent regulation of α-E catenin in the RAW 264.7 macrophage cell line

10.1101/2021.04.14.439728 ◽

2021 ◽

Author(s):

Waruni C. Dissanayake ◽

Jin Kyo Oh ◽

Brie Sorrenson ◽

Peter R. Shepherd

Keyword(s):

Gene Expression ◽

High Glucose ◽

Inflammatory Responses ◽

Macrophage Polarization ◽

Mrna Level ◽

Biosynthesis Pathway ◽

Glucose Levels ◽

Raw264.7 Macrophages ◽

Hexosamine Biosynthesis ◽

Hexosamine Biosynthesis Pathway

AbstractHigh glucose levels are associated with changes in macrophage polarization and evidence indicates that the sustained or even short-term high glucose levels modulate inflammatory responses in macrophages. However, the mechanism by which macrophages can sense the changes in glucose levels are not clearly understood. We find that high glucose levels rapidly increase the α-E catenin protein level in RAW264.7 macrophages. We also find an attenuation of glucose induced increase of α-E catenin when hexosamine biosynthesis pathway is inhibited either with glutamine depletion or with the drugs azaserine and tunicamycin. This indicates the involvement of hexosamine biosynthesis pathway in this process. Then, we investigated the potential role of α-E catenin in glucose induced macrophage polarization. We find that the reduction of α-E catenin level using siRNA attenuates the glucose induced change of IL-1β mRNA level under LPS stimulated condition. Further, we identified that the depletion of α-E catenin also decreases the IL-12 gene expression in basal glucose conditions leading to a reduction of glucose induced changes in IL-12. Together this indicates that α-E catenin can sense the changes in glucose levels in macrophages via hexosamine biosynthesis pathway and also can modulate the glucose induced gene expression of inflammatory markers such as IL-1-β and IL-12. This identifies a new part of the mechanism by which macrophages are able to respond to changes in glucose levels.

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Role for leptin in promoting glucose mobilization during acute hyperosmotic stress in teleost fishes

Journal of Endocrinology ◽

10.1530/joe-13-0292 ◽

2013 ◽

Vol 220 (1) ◽

pp. 61-72 ◽

Cited By ~ 39

Author(s):

David A Baltzegar ◽

Benjamin J Reading ◽

Jonathon D Douros ◽

Russell J Borski

Keyword(s):

Amino Acid ◽

Plasma Glucose ◽

Metabolic Regulation ◽

Leptin Receptor ◽

Control Fish ◽

Plasma Metabolites ◽

Endocrine Regulation ◽

Glucose Levels ◽

Lactate Levels

Osmoregulation is critical for survival in all vertebrates, yet the endocrine regulation of this metabolically expensive process is not fully understood. Specifically, the function of leptin in the regulation of energy expenditure in fishes, and among ectotherms, in general, remains unresolved. In this study, we examined the effects of acute salinity transfer (72 h) and the effects of leptin and cortisol on plasma metabolites and hepatic energy reserves in the euryhaline fish, the tilapia (Oreochromis mossambicus). Transfer to 2/3 seawater (23 ppt) significantly increased plasma glucose, amino acid, and lactate levels relative to those in the control fish. Plasma glucose levels were positively correlated with amino acid levels (R2=0.614), but not with lactate levels. The mRNA expression of liver leptin A (lepa), leptin receptor (lepr), and hormone-sensitive and lipoprotein lipases (hslandlpl) as well as triglyceride content increased during salinity transfer, but plasma free fatty acid and triglyceride levels remained unchanged. Both leptin and cortisol significantly increased plasma glucose levelsin vivo, but only leptin decreased liver glycogen levels. Leptin decreased the expression of liverhslandlplmRNAs, whereas cortisol significantly increased the expression of these lipases. These findings suggest that hepatic glucose mobilization into the blood following an acute salinity challenge involves both glycogenolysis, induced by leptin, and subsequent gluconeogenesis of free amino acids. This is the first study to report that teleost leptin A has actions that are functionally distinct from those described in mammals acting as a potent hyperglycemic factor during osmotic stress, possibly in synergism with cortisol. These results suggest that the function of leptin may have diverged during the evolution of vertebrates, possibly reflecting differences in metabolic regulation between poikilotherms and homeotherms.

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Computational Analysis of Insulin-Glucagon Signalling Network: Implications of Bistability to Metabolic Homeostasis and Disease states

Scientific Reports ◽

10.1038/s41598-019-50889-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Pramod R. Somvanshi ◽

Manu Tomar ◽

Venkatesh Kareenhalli

Keyword(s):

Plasma Glucose ◽

Positive Feedback ◽

Metabolic Regulation ◽

Metabolic Homeostasis ◽

Glucose Levels ◽

Disease States ◽

Signalling Network ◽

Catabolic Response ◽

Low Glucose ◽

Obesity And Cancer

Abstract Insulin and glucagon control plasma macronutrient homeostasis through their signalling network composed of multiple feedback and crosstalk interactions. To understand how these interactions contribute to metabolic homeostasis and disease states, we analysed the steady state response of metabolic regulation (catabolic or anabolic) with respect to structural and input perturbations in the integrated signalling network, for varying levels of plasma glucose. Structural perturbations revealed: the positive feedback of AKT on IRS is responsible for the bistability in anabolic zone (glucose >5.5 mmol); the positive feedback of calcium on cAMP is responsible for ensuring ultrasensitive response in catabolic zone (glucose <4.5 mmol); the crosstalk between AKT and PDE3 is responsible for efficient catabolic response under low glucose condition; the crosstalk between DAG and PKC regulates the span of anabolic bistable region with respect to plasma glucose levels. The macronutrient perturbations revealed: varying plasma amino acids and fatty acids from normal to high levels gradually shifted the bistable response towards higher glucose range, eventually making the response catabolic or unresponsive to increasing glucose levels. The analysis reveals that certain macronutrient composition may be more conducive to homeostasis than others. The network perturbations that may contribute to disease states such as diabetes, obesity and cancer are discussed.

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Computational Analysis of Insulin-Glucagon Signalling Network: Implications of Bistability in Metabolic Homeostasis and Disease states

10.1101/509208 ◽

2019 ◽

Author(s):

Pramod R Somvanshi ◽

Manu Tomar ◽

Venkatesh Kareenhalli

Keyword(s):

Plasma Glucose ◽

Positive Feedback ◽

Metabolic Regulation ◽

Metabolic Homeostasis ◽

Glucose Levels ◽

Disease States ◽

Signalling Network ◽

Catabolic Response ◽

Low Glucose ◽

Obesity And Cancer

AbstractInsulin and glucagon control plasma macronutrient homeostasis through their signalling network composed of multiple feedback and crosstalk mechanisms. To understand how these interactions contribute to metabolic homeostasis and disease states, we analysed the steady state response of metabolic regulation (catabolic or anabolic) with respect to structural and input perturbations in the integrated signalling network, for varying levels of plasma glucose. Structural perturbations revealed: the positive feedback of AKT on IRS is responsible for the bistability in anabolic zone (glucose >5.5 mmol); the positive feedback of calcium on cAMP is responsible for ensuring ultrasensitive response in catabolic zone (glucose <4.5 mmol); the crosstalk between AKT and PDE3 is responsible for efficient catabolic response under low glucose condition; the crosstalk between DAG and PKC regulates the span of anabolic bistable region with respect to plasma glucose levels. The macronutrient perturbations revealed: varying plasma amino acids and fatty acids from normal to high levels gradually shifted the bistable response towards higher glucose range eventually making the response catabolic or unresponsive to increasing glucose levels. The analysis reveals that certain macronutrient composition may be more conducive to homeostasis than others. The network perturbations that may contribute to disease states such as diabetes, obesity and cancer are discussed.

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