Effects of crustacean hyperglycemic hormone (CHH) RNA interference on regulation of glucose metabolism in Litopenaeus vannamei after ammonia-N exposure

2021 ◽  
pp. 1-40
Author(s):  
Xin Zhang ◽  
Luqing Pan ◽  
Ruixue Tong ◽  
Yufen Li ◽  
Lingjun Si ◽  
...  

Abstract To unveil the adaptation of Litopenaeus vannamei to elevated ambient ammonia-N, crustacean hyperglycemic hormone (CHH) was knocked down to investigate its function in glucose metabolism pathway under ammonia-N exposure. When CHH was silenced, haemolymph glucose increased significantly during 3-6 h, decreased significantly during 12-48 h, and recovered to the control groups’ level at 72 h. After CHH knockdown, DA contents reduced significantly during 3-24 h, which recovered after 48 h. Besides, the expressions of GC and DA1R in the hepatopancreas decreased significantly, while DA4R increased significantly. Correspondingly, the contents of cAMP, cGMP and DAG and the expressions of PKA, PKG, AMPKα and AMPKγ were significantly downregulated, while the levels of PKC and AMPKβ were significantly upregulated. The expressions of CREB and GLUT2 decreased significantly, while GLUT1 increased significantly. Moreover, glycogen content, glycogen synthase and glycogen phosphorylase activities in hepatopancreas and muscle were significantly increased. Furthermore, the levels of key enzymes HK, PK and PFK in glycolysis, rate-limiting enzymes CS in TCA, and critical enzymes PEPCK, FBP and G6P in gluconeogenesis were significantly decreased in hepatopancreas. These results suggest that CHH affects DA, and then they affect their receptors respectively to transmit glucose metabolism signals into the hepatopancreas of L. vannamei under ammonia-N stress. CHH acts on cGMP-PKG-AMPKα-CREB pathway through GC, and CHH affects DA to influence cAMP-PKA-AMPKγ-CREB and DAG-PKC-AMPKβ-CREB pathways, thereby regulating GLUTs, inhibiting glycogen metabolism and promoting glycolysis and gluconeogenesis. This study contributes to further understand glucose metabolism mechanism of crustacean in response to environmental stress.

1991 ◽  
Vol 260 (6) ◽  
pp. E927-E932 ◽  
Author(s):  
L. Coderre ◽  
A. K. Srivastava ◽  
J. L. Chiasson

With the use of the hindlimb perfusion technique, the effect of glucocorticoid on the regulation of glycogen metabolism was studied in rat skeletal muscle. Rats were adrenalectomized (ADX) or sham operated (controls) 14 days before the study. The ADX animals were treated with either saline or corticosterone, and the hindlimbs were perfused at rest or during muscle contraction with saline or epinephrine (10(-7) M). In the resting state, the glycogen content was 33.0 +/- 1.9 mumol/g in the controls, and the activity ratios of glycogen phosphorylase (GPase) and glycogen synthase (GSase) were 0.27 +/- 0.03 and 0.15 +/- 0.02, respectively. Epinephrine treatment increased GPase activity (0.78 +/- 0.03) and decreased GSase activity (0.05 +/- 0.01), which resulted in decreased glycogen content (25.7 +/- 0.9 mumol/g; P less than 0.01). Adrenalectomy induced a 35% reduction in glycogen content but had no effect on the activities of basal enzymes. Under these conditions, however, epinephrine had no effect on GPase activity, had a diminished effect on GSase activity (0.11 +/- 0.01), and did not induce further glycogen breakdown. Corticosterone replacement normalized muscle glycogen content in ADX rats as well as the response of the enzymes to epinephrine. Muscle contraction resulted in a decrease in glycogen content (8.9 +/- 1.3 mumol/g) and in GPase activity (0.14 +/- 0.02) and an increase in GSase activity (0.25 +/- 0.01); this was not affected by adrenalectomy nor by epinephrine. In conclusion, these data indicate that glucocorticoid is essential for the effects of epinephrine on GPase activation. on GSase inhibition, and consequently on glycogen breakdown in resting muscle.(ABSTRACT TRUNCATED AT 250 WORDS)


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 976
Author(s):  
Natalia N. Bezborodkina ◽  
Sergey V. Okovityi ◽  
Boris N. Kudryavtsev

Chronic hepatitises of various etiologies are widespread liver diseases in humans. Their final stage, liver cirrhosis (LC), is considered to be one of the main causes of hepatocellular carcinoma (HCC). About 80–90% of all HCC cases develop in LC patients, which suggests that cirrhotic conditions play a crucial role in the process of hepatocarcinogenesis. Carbohydrate metabolism in LC undergoes profound disturbances characterized by altered glycogen metabolism. Unfortunately, data on the glycogen content in LC are few and contradictory. In this study, the material was obtained from liver biopsies of patients with LC of viral and alcohol etiology and from the liver tissue of rats with CCl4-induced LC. The activity of glycogen phosphorylase (GP), glycogen synthase (GS), and glucose-6-phosphatase (G6Pase) was investigated in human and rat liver tissue by biochemical methods. Total glycogen and its labile and stable fractions were measured in isolated individual hepatocytes, using the cytofluorometry technique of PAS reaction in situ. The development of LC in human and rat liver was accompanied by an increase in fibrous tissue (20- and 8.8-fold), an increase in the dry mass of hepatocytes (by 25.6% and 23.7%), and a decrease in the number of hepatocytes (by 50% and 28%), respectively. The rearrangement of the liver parenchyma was combined with changes in glycogen metabolism. The present study showed a significant increase in the glycogen content in the hepatocytes of the human and the rat cirrhotic liver, by 255% and 210%, respectively. An increased glycogen content in cells of the cirrhotic liver can be explained by a decrease in glycogenolysis due to a decreased activity of G6Pase and GP.


1995 ◽  
Vol 269 (1) ◽  
pp. E27-E32 ◽  
Author(s):  
M. Lofman ◽  
H. Yki-Jarvinen ◽  
M. Parkkonen ◽  
J. Lindstrom ◽  
L. Koranyi ◽  
...  

To examine whether changes in the glycogen synthase protein concentration contribute to impaired insulin-stimulated glycogen metabolism in patients with noninsulin-dependent diabetes mellitus (NIDDM), muscle biopsies were taken before and after a 4-h euglycemic hyperinsulinemic clamp to measure glycogen synthase activity and glycogen synthase protein concentrations in 14 patients with NIDDM and in 17 control subjects. Nonoxidative glucose metabolism was reduced by 64% in patients with NIDDM compared with control subjects and correlated with insulin-stimulated glycogen synthase activity (r = 0.55, P < 0.05). The concentration of glycogen synthase protein in skeletal muscle was higher in patients with NIDDM than in control subjects (6.75 +/- 0.88 vs. 4.41 +/- 0.50 counts.min-1.micrograms protein-1, P < 0.05), whereas there was no significant difference in glycogen synthase mRNA concentration between the two groups. The glycogen synthase protein concentration correlated inversely with the rate of nonoxidative glucose metabolism (r = -0.63, P < 0.05). These findings indicate that the amount of glycogen synthase protein is increased in skeletal muscle of patients with NIDDM. The increase in the glycogen synthase protein may serve to compensate for a functional defect in the activation of the enzyme by insulin.


1983 ◽  
Vol 61 (4) ◽  
pp. 191-197 ◽  
Author(s):  
Bhagu R. Bhavnani

Optimum conditions were established for the assay of glycogen, glycogen synthase, glycogen phosphorylase, phosphoglucomutase, and glucose-6-phosphatase in rabbit fetal heart, lung, and liver. Using these methods, the pattern of appearance of glycogen and the above four enzymes was established from day 18 of gestation to day 8 after birth. The results indicate that total tissue glycogen reaches maximum levels between days 22 and 24 in the heart, days 24 and 26 in the lung, and days 30 and 31 in the liver. In all three tissues, the rapid rise or depletion of glycogen is coincident with a corresponding increase in glycogen synthase and glycogen phosphorylase activities. However, substantial amounts of glycogen synthase are present both prior to and after the accumulation of glycogen. Similarly, considerable amounts of glycogen phosphorylase are present early in gestation, yet deposition of glycogen occurs. Both the I and D forms of glycogen synthase are present in the three tissues, the major being the physiologically inactive D form. Similarly both the a and b forms of glycogen phosphorylase are present, with the a form (active form) making up about 30–60% of the total phosphorylase activity. Glucose-6-phosphatase was absent in fetal heart and lung throughout the period of gestation investigated. Low levels of this enzyme were detectable in fetal liver near term. The phosphoglucomutase activity increased progressively from day 22 of gestation in all three tissues and continues to increase after birth. The disappearance of fetal lung glycogen occurs between days 27 and 28 at a time when surfactant phospholipids first appear. These findings indicate that the breakdown of glycogen is providing the fetal lung cells with energy necessary for surfactant phospholipid biosynthesis.


2004 ◽  
Vol 378 (3) ◽  
pp. 1073-1077 ◽  
Author(s):  
Carlos LERÍN ◽  
Eulàlia MONTELL ◽  
Teresa NOLASCO ◽  
Mar GARCÍA-ROCHA ◽  
Joan J. GUINOVART ◽  
...  

Pharmacological inhibition of liver GP (glycogen phosphorylase), which is currently being studied as a treatment for Type II (non-insulin-dependent) diabetes, may affect muscle glycogen metabolism. In the present study, we analysed the effects of the GP inhibitor CP-91149 on non-engineered or GP-overexpressing cultured human muscle cells. We found that CP-91149 treatment decreased muscle GP activity by (1) converting the phosphorylated AMP-independent a form into the dephosphorylated AMP-dependent b form and (2) inhibiting GP a activity and AMP-mediated GP b activation. Dephosphorylation of GP was exerted, irrespective of incubation of the cells with glucose, whereas inhibition of its activity was synergic with glucose. As expected, CP-91149 impaired the glycogenolysis induced by glucose deprivation. CP-91149 also promoted the dephosphorylation and activation of GS (glycogen synthase) in non-engineered or GP-overexpressing cultured human muscle cells, but exclusively in glucose-deprived cells. However, this inhibitor did not activate GS in glucose-deprived but glycogen-replete cells overexpressing PTG (protein targeting to glycogen), thus suggesting that glycogen inhibits the CP-91149-mediated activation of GS. Consistently, CP-91149 promoted glycogen resynthesis, but not its overaccumulation. Hence, treatment with CP-91149 impairs muscle glycogen breakdown, but enhances its recovery, which may be useful for the treatment of Type II (insulin-dependent) diabetes.


1983 ◽  
Vol 54 (1) ◽  
pp. 45-50 ◽  
Author(s):  
D. Chasiotis ◽  
K. Sahlin ◽  
E. Hultman

The regulation of glycogenolysis in human muscle during epinephrine infusion has been investigated. The content of cAMP in resting muscle was 2.7 +/- 0.7 (SD) mumol . kg dry muscle-1 and increased threefold during the first 5 min of infusion. Total glycogen phosphorylase and glycogen synthase activities were unchanged during the infusion. The proportion of phosphorylase in the a form in the basal state was estimated to be at least 22.5% and during infusion 80–90%. During infusion, synthase I activity decreased. The muscle glycogen content was 340 mmol . kg dry wt-1 and decreased during the first 2 min of infusion at a rate of 11.0 mmol glycosyl units . kg dry wt-1 . min-1. Prolonged infusion resulted in a much lower glycogenolytic rate, even though most of the phosphorylase was still in the a form. Accumulation of hexose monophosphates and lactate followed the changes in glycogen. It was concluded that despite the almost total transformation of phosphorylase to the a form, the in vivo activity was maintained at a low level. It is suggested that this may be due to a low concentration of inorganic phosphate at the active site of the enzyme.


2005 ◽  
Vol 25 (21) ◽  
pp. 9713-9723 ◽  
Author(s):  
Young-Bum Kim ◽  
Odile D. Peroni ◽  
William G. Aschenbach ◽  
Yasuhiko Minokoshi ◽  
Ko Kotani ◽  
...  

ABSTRACT Mice with muscle-specific knockout of the Glut4 glucose transporter (muscle-G4KO) are insulin resistant and mildly diabetic. Here we show that despite markedly reduced glucose transport in muscle, muscle glycogen content in the fasted state is increased. We sought to determine the mechanism(s). Basal glycogen synthase activity is increased by 34% and glycogen phosphorylase activity is decreased by 17% (P < 0.05) in muscle of muscle-G4KO mice. Contraction-induced glycogen breakdown is normal. The increased glycogen synthase activity occurs in spite of decreased signaling through the insulin receptor substrate 1 (IRS-1)-phosphoinositide (PI) 3-kinase-Akt pathway and increased glycogen synthase kinase 3β (GSK3β) activity in the basal state. Hexokinase II is increased, leading to an approximately twofold increase in glucose-6-phosphate levels. In addition, the levels of two scaffolding proteins that are glycogen-targeting subunits of protein phosphatase 1 (PP1), the muscle-specific regulatory subunit (RGL) and the protein targeting to glycogen (PTG), are strikingly increased by 3.2- to 4.2-fold in muscle of muscle-G4KO mice compared to wild-type mice. The catalytic activity of PP1, which dephosphorylates and activates glycogen synthase, is also increased. This dominates over the GSK3 effects, since glycogen synthase phosphorylation on the GSK3-regulated site is decreased. Thus, the markedly reduced glucose transport in muscle results in increased glycogen synthase activity due to increased hexokinase II, glucose-6-phosphate, and RGL and PTG levels and enhanced PP1 activity. This, combined with decreased glycogen phosphorylase activity, results in increased glycogen content in muscle in the fasted state when glucose transport is reduced.


1993 ◽  
Vol 265 (5) ◽  
pp. E743-E751
Author(s):  
C. Chen ◽  
P. F. Williams ◽  
I. D. Caterson

Glycogen metabolism in the liver, skeletal muscle, cardiac muscle, and white adipose tissue was studied in gold thioglucose (GTG) obese mice after fasting and during refeeding. Prolonged (48 h) fasted control and GTG mice were refed with standard laboratory diet for 24 h. During fasting and refeeding, the changes in glycogen content and the activity of glycogen synthase I and R and phosphorylase alpha in the liver were similar in lean and GTG mice. However, the glycogen storage in the livers from GTG mice was always greater than that in lean animals. In GTG mice the activity of liver glycogen synthase I and R was significantly higher than that in lean animals 3 and 6 h after refeeding. The activity of liver phosphorylase alpha in GTG mice was higher than that in lean mice after refeeding. There were no significant differences in the glycogen content of white adipose tissue, cardiac muscle, and skeletal muscle from lean and GTG mice during the entire study. The results of this study suggest that increased glycogen storage in the liver is a major alteration in nonoxidative glucose metabolism and contributes to the development of insulin resistance and glucose intolerance in GTG obese mice.


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