Insulin and 20-hydroxyecdysone action in Bombyx mori: Glycogen content and expression pattern of insulin and ecdysone receptors in fat body

Keshan, Bela; Thounaojam, Bembem; Kh., Sanathoibi D.

doi:10.1016/j.ygcen.2016.06.022

Cited by 28 publications

(25 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(Fig. 7B) Glycogen content has been detected under different stress conditions, including starvation, cold hardness, over-winter or seasonal acclimation, and diapauses in previous studies (Koštál et al 2014; Heydari and Izadi 2014; Ren et al 2015; Keshan et al 2016; Wang et al 2016a,b), but few studies reported GP and GS expression levels and enzyme activity. Thus, more studies are needed to understand their function in insect physiology, including GP and GS RNAi to study the specific function of these two genes in glycogen and trehalose metabolism regulation, as well as in energy and chitin metabolism regulation in insects.…”

Section: Discussionmentioning

confidence: 79%

“…Given its importance in insects as an energy source, many studies focused on glycogen function under stress pressures like starvation and cold hardness (Koštál et al 2014; Heydari and Izadi 2014; Keshan et al 2016; Wang et al 2016a,b). The rate-limiting enzyme of glycogen degradation, GP, was first identified from rabbit skeletal muscle in 1936 (Cori and Cori 1936).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Glycogen Phosphorylase and Glycogen Synthase: Gene Cloning and Expression Analysis Reveal Their Role in Trehalose Metabolism in the Brown Planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae)

Zhang¹,

Wang²,

Chen³

et al. 2017

Journal of Insect Science

View full text Add to dashboard Cite

RNA interference has been used to study insects’ gene function and regulation. Glycogen synthase (GS) and glycogen phosphorylase (GP) are two key enzymes in carbohydrates’ conversion in insects. Glycogen content and GP and GS gene expression in several tissues and developmental stages of the Brown planthopper Nilaparvata lugens Stål (Hemiptera: Delphacidae) were analyzed in the present study, using quantitative reverse-transcription polymerase chain reaction to determine their response to double-stranded trehalases (dsTREs), trehalose-6-phosphate synthases (dsTPSs), and validamycin injection. The highest expression of both genes was detected in the wing bud, followed by leg and head tissues, and different expression patterns were shown across the developmental stages analyzed. Glycogen content significantly decreased 48 and 72 h after dsTPSs injection and 48 h after dsTREs injection. GP expression increased 48 h after dsTREs and dsTPSs injection and significantly decreased 72 h after dsTPSs, dsTRE1-1, and dsTRE1-2 injection. GS expression significantly decreased 48 h after dsTPS2 and dsTRE2 injection and 72 h after dsTRE1-1 and dsTRE1-2 injection. GP and GS expression and glycogen content significantly decreased 48 h after validamycin injection. The GP activity significantly decreased 48 h after validamycin injection, while GS activities of dsTPS1 and dsTRE2 injection groups were significantly higher than that of double-stranded GFP (dsGFP) 48 h after injection, respectively. Thus, glycogen is synthesized, released, and degraded across several insect tissues according to the need to maintain stable trehalose levels.

show abstract

Section: Discussionmentioning

confidence: 79%

mentioning

confidence: 99%

Glycogen Phosphorylase and Glycogen Synthase: Gene Cloning and Expression Analysis Reveal Their Role in Trehalose Metabolism in the Brown Planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae)

Zhang¹,

Wang²,

Chen³

et al. 2017

Journal of Insect Science

View full text Add to dashboard Cite

show abstract

“…On the other hand, the concentration of trehalose in fatty acid titers and hemolymph declined gradually over six days of starvation in the moth Heliothis virescens (Fabricius) (Lepidoptera, Noctuidae) ( Foster and Johnson, 2010 ). Other previously published studies have also demonstrated that glycogen and trehalose play an important role in starvation and conditions of food deprivation by regulating the expression of the insulin receptor (InR) via insulin and 20E ( Keshan et al, 2016 ; Matsuda et al, 2015 ). There have also been shown to be differences in the effects of starvation on trehalose and glycogen according to development, where trehalose and glycogen decreased in adults (in comparison to larvae) in response to starvation, as in the present study ( Fig.…”

Section: Discussionmentioning

confidence: 95%

“…In insects, starvation during the larval stage has been shown to reduce adult metabolic rates ( Wang et al, 2016a ) resulting in an increase in the energy stores of glycogen, triglycerides ( Wang et al, 2016a ), glucose, and trehalose in adults ( Kim and Hong, 2015 ; Wang et al, 2016a ; Zauner et al, 2000 ) during the intial stage of starvation; but it can result in a decrease in the content of trehalose and glucose with increasing time of starvation ( Laparie et al, 2012 ; Schilman and Roces, 2008 ). It is well known that starvation has been shown to be regulated by insulin and 20-hydroxyecdysone (20E) ( Keshan et al, 2016 ; Kim and Hong, 2015 ).…”

Section: Introductionmentioning

confidence: 99%

Effects of starvation on the carbohydrate metabolism in Harmonia axyridis (Pallas)

Shi

Wang

et al. 2017

Biology Open

View full text Add to dashboard Cite

Trehalose plays an important role in energy storage, metabolism, and protection from extreme environmental conditions in insects. Trehalose is the main blood sugar in insects, and it can be rapidly used as an energy source in times of need. To elucidate the mechanisms of the starvation response, we observed the effects of starvation on trehalose and glycogen, trehalase activity, and the relative gene expression of genes in the trehalose and glycogen metabolic pathways in the invasive beetle Harmonia axyridis. Our results show that trehalose levels and the activities of two types of trehalases decreased significantly in the first 8 h of starvation, while the relative expression of HaTreh1-1 increased. While trehalose remained nearly constant at a relatively high level from 8 to 24 h, glycogen levels decreased significantly from 8 h to 24 h of starvation. Likewise, glycogen phosphorylase (HaGP) expression was significantly higher at 12 to 24 h starvation than the first 8 h, while the expression of glycogen synthase (HaGS) was relatively stable. Furthermore, trehalose decreased significantly from 24 h starvation to 72 h starvation, while trehalase activities and the relative expression of some HaTreh genes generally increased toward the end of the starvation period. The expression of trehalose-6-phosphate synthase (HaTPS) increased significantly, supporting the increase in trehalose synthesis. These results show that trehalose plays a key role in the energy provided during the starvation process through the molecular and biochemical regulation of trehalose and glycogen metabolism.

show abstract

“…hydrate reserves in B. mori (54). A lower 20E concentration could not repress insulin function (30), and a higher 20E concentration is critical for antagonizing insulin function in H. armigera (55).…”

Section: Insulin and 20e Cross-talk To Regulate Insect Pupationmentioning

confidence: 92%

Insulin and 20-hydroxyecdysone oppose each other in the regulation of phosphoinositide-dependent kinase-1 expression during insect pupation

Pan

et al. 2018

Journal of Biological Chemistry

View full text Add to dashboard Cite

Insulin promotes larval growth of insects by stimulating the synthesis of the steroid hormone 20-hydroxyecdysone (20E), which induces pupation and apoptosis. However, the mechanism underlying the coordinate regulation of insect pupation and apoptosis by these two functionally opposing hormones is still unclear. Here, using the lepidopteran insect and serious agricultural pest Helicoverpa armigera (cotton bollworm) as a model, we report that phosphoinositide-dependent kinase-1 (PDK1) and forkhead box O (FoxO) play key roles in these processes. We found that the transcript levels of the PDK1 gene are increased during the larval feeding stages. Moreover, PDK1 expression was increased by insulin, but repressed by 20E. dsRNA-mediated PDK1 knockdown in the H. armigera larvae delayed pupation and resulted in small pupae and also decreased Akt/protein kinase B expression and increased FoxO expression. Furthermore, the PDK1 knockdown blocked midgut remodeling and decreased 20E levels in the larvae. Of note, injecting larvae with 20E overcame the effect of the PDK1 knockdown and restored midgut remodeling. FoxO overexpression in an H. armigera epidermal cell line (HaEpi) did not induce apoptosis, but promoted autophagy and repressed cell proliferation. These results reveal cross-talk between insulin and 20E and that both hormones oppose each other's activities in the regulation of insect pupation and apoptosis by controlling PDK1 expression and, in turn, FoxO expression. We conclude that sufficiently high 20E levels are a key factor for inducing apoptosis during insect pupation.

show abstract

Insulin and 20-hydroxyecdysone action in Bombyx mori: Glycogen content and expression pattern of insulin and ecdysone receptors in fat body

Cited by 28 publications

References 67 publications

Glycogen Phosphorylase and Glycogen Synthase: Gene Cloning and Expression Analysis Reveal Their Role in Trehalose Metabolism in the Brown Planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae)

Glycogen Phosphorylase and Glycogen Synthase: Gene Cloning and Expression Analysis Reveal Their Role in Trehalose Metabolism in the Brown Planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae)

Effects of starvation on the carbohydrate metabolism in Harmonia axyridis (Pallas)

Insulin and 20-hydroxyecdysone oppose each other in the regulation of phosphoinositide-dependent kinase-1 expression during insect pupation

Contact Info

Product

Resources

About