Decrease In Glycogen Research Articles

Fatty acid synthase 2 knockdown alters the energy allocation strategy between immunity and reproduction during infection by Micrococcus luteus in Locusta migratoria

Immunity and reproduction are vital functions for the survival and population maintenance of female insects. However, owing to limited resources, these two functions cannot be fulfilled simultaneously, resulting in an energy tradeoff between them. Notably, the mechanisms underlying this immune-reproductive trade-off, in which energy competition likely plays a central role, remain poorly understood. Fatty acid synthase (FAS), a key gene involved in lipid synthesis and insect energy metabolism, was investigated in this study using Locusta migratoria as the research subject. Bacterial infection and RNA interference (RNAi) technology were used to examine changes in the immunity, fecundity, and energy metabolism patterns of locusts under different treatments. The findings of this study demonstrate that infection with Micrococcus luteus triggers an immune response in locusts, significantly upregulates the expression of defensin 3 (DEF3) and Attacin, and enhances pHenoloxidase (PO) activity. Upon FAS2 silencing, bacterial attack upregulated DEF3 and Attacin expression to a lesser extent, leading to increased lysozyme activity instead of PO. Furthermore, bacterial infection results in a decrease in glycogen and glucose content in the fat body, accompanied by a significant increase in triacylglycerol (TAG) content. However, after FAS2 knockdown, both the lipid and carbohydrate contents were significantly reduced in the fat body. Compared with bacterial infection alone, low FAS2 expression further exacerbated fecundity impairment in locusts. The expression levels of vitellogenin A (VgA) and vitellogenin B (VgB) were significantly low, with severe ovarian atrophy observed. Notably, the ovarian weight was only 21 % compared to that of the control group. Moreover, females exhibited minimal egg-laying behavior. In summary, our findings suggest that following FAS2 gene silencing, there is a greater inclination toward immune stimulation energy activation in locusts, whereas reproductive investment is reduced. The outcomes of this study will contribute to the further exploration of the molecular mechanisms underlying the trade-off between immune and reproductive energy in locusts.

Tryptophan supplements in high-carbohydrate diets by improving insulin response and glucose transport through PI3K-AKT-GLUT2 pathways in blunt snout bream (Megalobrama amblycephala)

The aim of this experiment was to elucidate the metabolic ramifications of tryptophan supplementation in the context of high-carbohydrate diet-feeding, which is important for improving feeding strategies in aquaculture in order to improve fish carbohydrate metabolism. Juvenile blunt snout bream with an initial mean body mass of 55.0±0.5 g were allocated to consume one of three experimental diets: CN, a normal diet with carbohydrate content of 30% (w/w); HC, a diet with high carbohydrate content of 43% (w/w); and HL, a high-carbohydrate diet to which 0.8% L-tryptophan (L-trp) had been added. These diets were fed for 8 weeks, and the effects of the carbohydrate and tryptophan contents of the diets were assessed.Histological analysis using Hematoxylin and Eosin (H&E) and Oil Red O staining revealed that high-carbohydrate intake was associated with abnormal hepatocyte morphology and excessive liver lipid accumulation, which were notably ameliorated by tryptophan supplementation. A significant increase in plasma glucose, glucagon, AGEs (advanced glycation end products), triglycerides, total cholesterol, and a significant decrease in insulin and hepatic glycogen after a high-carbohydrate diet in terms of plasma indices, compared to the control group. Almost all of them were restored to the normal level in the HL group. The present study might preliminarily suggest that tryptophan supplementation ameliorates the imbalance in glucose metabolism of this species induced by a high-carbohydrate diet. Transcriptomics showed that glucose metabolism under high carbohydrate was mainly regulated by the PI3K-AKT signaling pathway. The mRNA expression and protein levels of GLUT2 also varied with this pathway, which would suggest that sustained activation of this pathway with the addition of tryptophan accelerates glucose transport and insulin secretion under high-carbohydrate diet. Subsequent GTT and ITT experiments have also demonstrated that tryptophan improves glucose tolerance and insulin tolerance in blunt snout bream on a high-carbohydrate diet.In conclusion, these findings elucidate the positive regulatory effect of tryptophan on the PI3K-AKT-GLUT2 pathway under a high carbohydrate diet and provide a theoretical basis for the subsequent rational application of high carbohydrate diets in the future.

Anti-diabetic activity of aqueous extract of Trichilia prieureana A. Juss leaves in fructose-fed streptozotocin-induced diabetic male Wistar rats

Background and aimEthanolic extract of Trichilia prieureana leaves have been reported to exhibit anti-hyperglycemic activities without detailed information on the anti-diabetic activities. This study investigated the anti-diabetic activity of aqueous extract of T. prieureana leaves (AETPL) in type 2 diabetic (T2DM) male rats. Experimental procedureT2DM rats (induced with 10 % fructose solution ad libitum for 2 weeks and streptozotocin [STZ]; 40 mg/kg body weight {BW}) in groups B, C, D, E, and F were also administered distilled water (DW), metformin (100 mg/kg BW), 11.2, 22.3, and 44.6 mg/kg BW of AETPL, respectively, whilst non-diabetic rats in Group A received DW only (Sham Control, SC) for 14 days. The T2DM-related parameters were then evaluated. ResultsThe fructose-fed streptozotocin-(FSTZ) treatment related significant (p < 0.05) increases in FBS, HbA1c, fructosamine, HOMA-IR, G6P, GP, TC, TG, LDL-C, urea, bilirubin, hepatic and pancreatic MDA levels; decreases in BW, serum insulin, creatinine, albumin, HOMA-β, glycogen, G6PD, HK, HDL-C, hepatic and pancreatic SOD, GPX, RG, catalase, Hb, PCV, MCH, MCHC, MCV, RBC, WBC, differentials and the destruction of the pancreatic β-cells, hepatocyte degeneration, and central hepatic vein congestion were reversed by AETPL, to values that compared well with SC in most cases. In the IpGGT model, the intraperitoneally administered AETPL reduced the blood glucose and elevated the plasma insulin levels. The AETPL at 44.6 mg/kg BW exhibited the most pronounced effects. ConclusionAETPL (44.6 mg/kg BW) restored T2DM-glycemic control and associated biochemical changes via up-regulation of insulin, carbohydrate metabolizing enzymes and restoration of pancreatic and hepatic histoarchitecture.

Dose-dependent alteration in hepatic and cerebral glucose metabolism following exposure to polystyrene microplastic in Wistar rats

Background: Recently, microplastics (MPs) with dimensions less than 5 mm have gained more attention due to their adverse impact on the environment and living creatures. Polystyrene (PS) particle is a key element of primary microplastics, which are causing numerous health issues such as interruption of energy metabolism, oxidative stress, neurotoxicity, immunotoxicity, digestive gland disorders, reproductive disruption, and genotoxicity in marine living organisms. Method: Alteration in carbohydrate metabolism was evaluated in male Wistar rats (six weeks of age) after four weeks of oral exposure to polystyrene microplastic (PS-MP) at three different doses (0.5mg/L, 5mg/L and 50 mg/L via drinking water). Results: Polystyrene exposure caused a significant decrease in blood glucose, liver glycogen, and pyruvic acid content in liver and cerebral tissue. Free amino nitrogen content significantly altered in the liver and cerebrum in a dose-specific manner. The LDH activity was found to be decreased in the liver, whereas it increased in the cerebral cortex of rats in a dose-responsive fashion. Enzymes like glucose 6-phosphatase, GOT, GPT, and succinate dehydrogenase activities demonstrated differential effects on the liver and cerebrum of rats in terms of energy metabolism. Conclusion: It is suggested that sub-acute polystyrene exposure significantly perturbs glucose metabolism by inducing hypoglycemia associated with decreased glycolysis and increased TCA cycle enzyme function in rat liver in a dose-dependent manner. Gluconeogenesis is also affected differentially by metabolic adjustment in the studied organs.

THE ROLE OF INTRAUTERINE ANTIGEN EXPOSURE IN THE MORPHOGENESIS OF CEREBRAL BLOOD VESSELS

Introduction. The state of cerebral vessels in children of the first year of life with congenital toxoplasmosis, both active and without signs of activity (as models of antenatal antigenic exposure), was considered. The patients were born to mothers whose pregnancy proceeded with mild preeclampsia and perinatal damage to the nervous system. The features of the morphogenesis of the brain vessels of rats after exposure to antigens in the antenatal period were experimentally investigated. Materials and Methods. 119 children of the first year of life were examined. 43 patients with toxoplasmosis, 25 children from women whose pregnancy was complicated by mild preeclampsia, and 28 children with perinatal lesions of the nervous system of hypoxic-ischemic genesis due to antenatal hypoxia of the fetus. The comparison group consisted of 23 healthy children with an uncomplicated antenatal history. Experimental study of the morphogenesis of brain vessels of Wistar rats after intrauterine administration of antigens according to the method of M.A. Voloshin. Results. At 1–2 and 7–8 months of life, in children with antigenic antenatal exposure and perinatal lesions of the nervous system of hypoxic-ischemic genesis, blood flow disorders in the anterior cerebral arteries, vessels of the nail bed, manifestations of endothelial dysfunction and impaired function of the sympathoadrenal system were detected. In the experiment, after the intrauterine introduction of antigens of various nature, an increase in the proportion of the connective tissue component in blood vessels was established, and a significant decrease in the ratio of muscle and connective tissue components from the 1st to the 60th day of postnatal development. Changes in indicators of carbohydrate metabolism and a decrease in glycogen in the anterior cerebral artery of rats 1–60 days of life with antigenic antenatal exposure indicate long-term changes in metabolic disorders of carbohydrate metabolism in the anterior cerebral arteries. By extrapolating the results obtained in the experiment on rats, it is possible to predict metabolic disorders in the vessels of people of the appropriate age, which to a certain extent explains the ultrasound and biomicroscopic changes in vessels, endothelial dysfunction detected in children with antigenic antenatal stimulation at 1–2 and 7–8 months of life. Conclusions. The identified features indicate a change in the morphogenesis of brain vessels after antenatal antigenic exposure and are the background for the formation of central nervous system pathology in children

To Evaluate the Hepatoprotective Activity of Leaves of Salacia Chinensis Linn. on CCl4 Induced Albino Wistar Rats

The main aim of the present study is to evaluate the Hepatoprotective activity of aqueous slurry of leaves of Salacia chinensis Linn .on CCl4 induced liver damage in rats. Hepatotoxicity was induced by CCl4 and the biochemical parameters such as serum glutamate pyruvate transminase (sGPT), serum glutamate oxaloacetate transaminase (sGOT), alkaline phosphatase (sALP), Blood glucose level, Liver glycogen level and histopathological changes in liver were studied along with silimarin as standard Hepatoprotective agents. The Phytochemical investigation of the aqueous slurry showed significant decrease in the levels of sGPT, sGOT, sALP as compared to the animals treated with Silimarin, a known, standard hepatoprotective agent. A significant decrease in blood sugar level and liver glycogen was also observed in the animals treated with aqueous slurry of leaves of Salacia chinensis Linn.

Investigation of anti-diabetic effect of a novel coenzyme Q10 derivative.

Introduction: The rising incidence of type 2 diabetes has seriously affected international public health. The search for more drugs that can effectively treat diabetes has become a cutting-edge trend in research. Coenzyme Q10 (CoQ10) has attracted much attention in the last decade due to its wide range of biological activities. Many researchers have explored the clinical effects of CoQ10 in patients with type 2 diabetes. However, CoQ10 has low bio-availability due to its high lipophilicity. Therefore, we have structurally optimized CoQ10 in an attempt to exploit the potential of its pharmacological activity. Methods: A novel coenzyme Q10 derivative (L-50) was designed and synthesized by introducing a group containing bromine atom and hydroxyl at the terminal of coenzyme Q10 (CoQ10), and the antidiabetic effect of L-50 was investigated by cellular assays and animal experiments. Results: Cytotoxicity results showed that L-50 was comparatively low toxicity to HepG2 cells. Hypoglycemic assays indicated that L-50 could increase glucose uptake in IR-HepG2 cells, with significantly enhanced hypoglycemic capacity compared to the CoQ10. In addition, L-50 improved cellular utilization of glucose through reduction of reactive oxygen species (ROS) accumulated in insulin-resistant HepG2 cells (IR-HepG2) and regulation of JNK/AKT/GSK3β signaling pathway, resulting in hypoglycemic effects. Furthermore, the animal experiments demonstrated that L-50 could restore the body weight of HFD/STZ mice. Notably, the findings suggested that L-50 could improve glycemic and lipid metabolism in HFD/STZ mice. Moreover, L-50 could increase fasting insulin levels (FINS) in HFD/STZ mice, leading to a decrease in fasting blood glucose (FBG) and hepatic glycogen. Furthermore, L-50 could recover triglycerides (TG), total cholesterol (T-CHO), lipoprotein (LDL-C) and high-density lipoprotein (HDL-C) levels in HFD/STZ mice. Discussion: The addition of a bromine atom and a hydroxyl group to CoQ10 could enhance its anti-diabetic activity. It is anticipated that L-50 could be a promising new agent for T2DM.

SAT001 Membrane Progesterone Receptors Induce Glycogenolysis In Uterine Epithelial Cells

Abstract Disclosure: M. Berg: None. M. Dean: None. In humans and cattle, 40-60% of pregnancies fail, with most losses occurring prior to or during implantation. Throughout this time, the developing embryo needs glucose to survive. The demand for glucose increases dramatically at the morula stage as the embryo enters the uterus. Yet, how glucose is regulated to match the changing needs of the embryo is unclear. Glycogen is composed of thousands of glucose molecules and is present in the uterine epithelium of many species. Our lab has shown that the glycogen content of the bovine uterine epithelium was lower during the luteal phase than at estrus. Therefore, our objective was to elucidate the role of progesterone in glycogenolysis of uterine epithelial cells. Bovine uterine epithelial (BUTE) cells were treated with insulin-like growth factor 1 (IGF1) to stimulate glycogenesis, followed by treatment for 48 hours. Progesterone decreased glycogen levels in BUTE cells by 99% (P=0.0002). RU486 did not block progesterone's effect, indicating that the effect of progesterone was not mediated by nuclear progesterone receptors (nPR). Thus, we hypothesized that the effect of progesterone is mediated by membrane progesterone receptors (mPRs). RT-PCR confirmed that BUTE cells expressed all five mPRs (α, β, γ, δ, and ε). Like progesterone, a specific mPR agonist (Org OD 02-0) decreased glycogen levels in BUTE cells by 99% (P&amp;lt;0.0001). Indicating a potential for mPRs to regulate glycogen in vivo, immunohistochemistry showed that the bovine uterine epithelium expressed high levels of mPRα. These results validate that progesterone is acting through mPRs to stimulate glycogen breakdown in BUTE cells. Once progesterone binds to the mPR, two signaling pathways can be activated, cAMP and AMPK. Neither progesterone nor Org OD 02-0 changed intracellular cAMP concentrations. In agreement, the adenylyl cyclase activator forskolin increased cAMP concentration but did not decrease glycogen. BUTE cells treated with progesterone had increased pAMPK levels at 24 hours compared to the control (P=0.0001). BUTE cells treated with an AMPK activator (D942) had a decrease in glycogen (P=0.0051). Supporting these results in vivo, pAMPK levels in the uterine epithelium were high in the bovine uterine epithelium during the luteal phase when glycogen levels were low. In a human model, progesterone and Org OD 02-0 decreased glycogen levels to a similar extent in Ishikawa cells that express mPRs but not nPRs (P=0.0027). In conclusion, progesterone acting through the mPR and AMPK to stimulate glycogenolysis may play a crucial role in providing glucose to endometrial tissue or the growing embryo. Presentation: Saturday, June 17, 2023

Toxicity assessment of microplastics within the Loire River in the clam Corbicula fluminea exposed to environmentally relevant exposure conditions.

The dispersed pollution caused by microplastics (MPs) represents a current and global concern. While the fragmentation of plastic debris into smaller particles occurs in rivers, little MP research is done on freshwater species and is published compared to the marine environment. The Loire River is the longest river in France and is subject to moderate to high anthropic pressure while it represents major societal and economic issues. However, there are not many studies that have been put forward with regards to the effect of environmental MPs (EMPs) on aquatic organisms and no policies have been enacted to monitor the plastic pollution. In this study, freshwater bivalves, Corbicula fluminea, were exposed for 21 days to environmentally relevant concentrations of a mixture of <200 µm MPs generated from plastic litter collected directly along the banks of the Loire River. This mixture was composed of 40% polyethylene (PE), 40% polypropylene (PP), 10% polyethylene terephthalate (PET) and 10% polyvinylchloride (PVC) (mass percentage). Ecotoxicological effects were assessed from the individual to the molecular levels on several endpoints: condition index, filtration efficiency, enzyme activities, lipid peroxidation, energy reserves and gene expression. The ingestion of EMPs caused damages at the biochemical level. Indeed, we reported an increase in catalase activity in gills and digestive mass, a decrease in TBARs in gills, a decrease in acetylcholinesterase activity in the digestive mass, a decrease of glycogen and lipid contents in the whole organisms and a significant induction of the expression of gst, cat, mp, acp genes. The current results suggest therefore that long-term exposure to realistic doses of EMPs causes toxicity towards freshwater benthic biota. The analysis of biomarker activities and the analysis of gene expression are complementary to prevent the effects of a plastic contamination at higher biological levels in aquatic organisms.

Effect of short neuropeptide F signaling on larval feeding in Mythimna separata.

Mythimna separata is a notorious phytophagous pest which poses serious threats to cereal crops owing to the gluttony of the larvae. Because short neuropeptide F (sNPF) and its receptor sNPFR are involved in a diversity of physiological functions, especially in functions related to feeding in insects, it is a molecular target for pest control. Herein, an sNPF and 2 sNPFRs were identified and cloned from M. separata. Bioinformatics analysis revealed that the sNPF and its receptors had a highly conserved RLRFamide C-terminus and 7 transmembrane domains, respectively. The sNPF and its receptor genes were distributed across larval periods and tissues, but 2 receptors had distinct expression patterns. The starvation-induced assay elucidated that sNPF and sNPFR expression levels were downregulated under food deprivation and recovered with subsequent re-feeding. RNA interference knockdown of sNPF, sNPFR1, and sNPFR2 by injection of double-stranded RNA into larvae not only suppressed food consumption and increased body size and weight, but also led to decrease of glycogen and total lipid contents, and increase of trehalose compared with double-stranded green fluorescent protein injection. Furthermore, molecular docking was performed on the interaction mode between sNPFR protein and its ligand sNPF based on the 3-dimensional models constructed by AlphaFold; the results indicated that both receptors were presumably activated by the mature peptide sNPF-2. These results revealed that sNPF signaling played a considerably vital role in the feeding regulation of M. separata and represents a potential control target for this pest.

Abstract 102: Imaging Markers Of Energy Metabolism In The Post-stroke Mouse Brain

Introduction: Cerebral ischemia results in a lesion comprised of dying cells surrounded by a band of tissue containing cells at risk of dying, called the penumbra. Understanding the status of energy metabolism in the stroke is necessary to get a clearer picture of the formation of the lesion, and may provide insights into potential therapeutic targets. The detection and distribution of energy metabolism biomarkers, particularly in ischemic brain tissue, presents significant challenges for conventional laboratory techniques due to the labile nature of these markers and the lack of unique chemical or spectroscopic handles. Fourier Transform infrared (FTIR) spectroscopic imaging can be used to map the distribution of different biochemical parameters, such as lipids, proteins, aggregated proteins, glycogen, lactate, pyruvate, ATP/ADP, NADH and glutamate. Methods: We employed the photothrombotic stroke model in adult mice to produce a permanent focal stroke lesion. Brain tissue was collected at multiple time points (1h to 4 weeks post-stroke). FTIR imaging was employed to map the distribution of unique biochemical fingerprints for over a dozen key metabolic markers. Immunohistochemistry was also performed on adjacent tissues to correlate biomarkers revealed by FTIR with the distribution of astrocytes, myelin and macrophages. Results: During the first week poststroke, the lesion shows decreased lipid esters, protein, ATP/ADP, NADH content while showing an increase in glutamate, aggregated protein, lactate and pyruvate. Glycogen can be seen to accumulate in the penumbra starting at 1 day post-stroke until 1 week post-stroke, which correlates with the appearance of astrocytes around the border of the stroke lesion. From 1 week to 4 weeks post-stroke, we observe an increase in lipid esters in the lesion, as well as a decrease in glycogen, lactate and pyruvate, while an increase in ATP/ADP and NADH can be observed. Conclusion: We are showing for the first time novel images of multiple energy metabolism biomarkers across a range of post-stroke time points in a mammalian brain. This type of imaging will be important in studying post-stroke interventions, particularly drugs that are known to alter energy metabolism.

Biochemical and Morphological Responses in Amazon Fish, Piaractus brachypomus Exposed To 2,4-D + Picloram Herbicide

Pesticides as herbicides present an elevated potential for contaminating the aquatic environment, being able to create negative effects for organisms that are not the target, like fish. We evaluated the morphology and function of the hepatic, branchial and renal tissue on Piaractus brachypomus exposed to the herbicide based on 2,4-D + Picloram. Fishes were exposed to a sublethal concentration of the herbicide Norton® (1.1 g L-1, corresponding to 420 mg L-1 of 2,4D and 100 mg L-1 of picloram) for 96 h. After exposure, the plasma, gills, liver, kidney and white muscle were sampled for biochemical and morphological analyses. Acute exposure induced an increase on plasmatic glucose and decrease of muscular glycogen, while the plasmatic protein was also decreased. Tissues GST-GSH enzymatic biotransformation pathway and lipid peroxidation (LPO) were unchanged after acute exposure. Histopathological indexes analysis showed alterations on gills, liver and kidney which was evidenced morphofunctional damage by histopathological organ indexes. The results demonstrate that the herbicide induce different organs responses characterized by morphological and metabolic alterations on P. brachypomus. The adjustments of energy demand and gill, liver and kidney morphological changes produced by Norton® may affect the capacity of vital functions and capacity for development and reproduction of the specie.

Level of blood glucose, fatigue and sexual anxiety in diabetes mellitus sufferers

Diabetes causes a decrease in glycogen which results in fatigue and neurovascular disorders which cause a decrease in body organ function. This condition raises their concerns about sexual problems in themselves and this is the main trigger for sexual problems in DM sufferers apart from physical problems. This study aims to determine the relationship between blood glucose levels and fatigue levels with sexual anxiety in diabetes mellitus sufferers. This research is correlational quantitative research with a cross-sectional time approach. The population of this study were DM sufferers in the Nalumsari Community Health Center working area with a sample of 36 people. The results of the analysis using the Spearman rho test obtained a P value of 0.000 so it can be concluded that there is a significant relationship between blood glucose levels and levels of fatigue and sexual anxiety in diabetes mellitus sufferers in the Nalumsari I Regional Health Center working area.

Parasitism enhances gastropod feeding on invasive and native algae while altering essential energy reserves for organismal homeostasis upon warming

Marine bioinvasions are of increasing attention due to their potential of causing ecological and economic loss. The seaweed Gracilaria vermiculophylla has recently invaded the Baltic Sea, where, under certain conditions, it was found to outcompete the native alga Fucus vesiculosus. Parasites of grazers and temperature are among the potential factors which might indirectly modulate the interactions between these co-occurring algae through their single and combined effects on grazing rates. We tested the temperature and parasitism effects on the feeding of the gastropod Littorina littorea on F. vesiculosus vs. G. vermiculophylla. Uninfected and trematode-infected gastropods were exposed to 10, 16, 22, and 28 °C for 4 days while fed with either algae. Faeces production was determined as a proxy for grazing rate, and HSP70 expression, glycogen and lipid concentrations were used to assess the gastropod's biochemical condition. Gracilaria vermiculophylla was grazed more than F. vesiculosus. Trematode infection significantly enhanced faeces production, decreased glycogen concentrations, and increased lipid concentrations in the gastropod. Warming significantly affected glycogen and lipid concentrations, with glycogen peaking at 16 °C and lipids at 22 °C. Although not significant, warming and trematode infection increased HSP70 levels. Increased faeces production in infected snails and higher faeces production by L. littorea fed with G. vermiculophylla compared to those which fed on F. vesiculosus, suggest parasitism as an important indirect modulator of the interaction between these algae. The changes in the gastropod's biochemical condition indicate that thermal stress induced the mobilization of energy reserves, suggesting a possible onset of compensatory metabolism. Finally, glycogen decrease in infected snails compared to uninfected ones might make them more susceptible to thermal stress.

Identification of the neuropeptide gene family and feeding regulation by neuropeptide Y in Mythimna separata (Lepidoptera: Noctuidae)

Mythimna separata is a crucial agricultural pest with polyphagous characteristic. Neuropeptide signaling, especially neuropeptide Y (NPY) involved in feeding regulation, is considered as a potential pest control target. In this study, we identified 50 neuropeptides including NPY of M. separata using transcriptome sequencing. Bioinformatics analysis showed that NPY had a conserved carboxyterminal motif of RGRYamide and shared very high homology across lepidopteran insects. Spatio-temporal expression profile articulated that NPY was mainly expressed in the larval stage, and with the highest expression in larval midgut and adult alimentary canal. RNAi knockdown by the injection of dsNPY into larvae significantly inhibited food uptake and body weight, delayed developmental duration, and also caused increase of trehalose and decrease of glycogen and total lipid compared to dsGFP. This study identified nearly the entire neuropeptide gene family of M. separata and further indicated that NPY signaling pathway might played a vital role in the feeding regulation and related to energy metabolism. Our results not only laid a preliminary foundation for functional studies on neuropeptide of M. separata, but also provided a potential molecular target for future pesticide development.

Carbohydrate Metabolism in Diabetic Rat’s Heart – The Effects of Acetylsalicylic Acid and Heat Preconditioning as HSP70 Inducers

Abstract The myocardium of diabetic subjects displays reduced HSP70 protein level and weak myocardial protection. However, the heart possesses an ability to produce heat shock proteins (HSPs) after exposure to sublethal heat stress. Acetylsalicylicacid (ASA) has the property of pharmacological induction of HSPs. We evaluated the common effects of single dose ASA-pretreatment, prior to heat preconditioning (HP), over carbohydrate metabolism-related enzymes and substrates in the heart of diabetic rats. Streptozotocin-diabetes caused significant decrease of HSP70 protein level, stimulation of the gluconeogenic processes and inhibition of glycolytic processes in the heart. HP-diabetic hearts have significantly higher HSP70 protein level, lower glycogen, glucose-6-phosphate content, glycogen phosphorylase and hexokinase activity, and higher glucose levels and PFK activity. ASA-pretreatment of HP-diabetic animals caused additional increase of HSP70, additional decrease of glycogen, glucose-6-phosphate, glycogen phosphorylase and hexokinase, and additional increase of glucose and PFK in the heart. In conclusion, HP is physiological inducer of HSP70 level in heart and tends to reverse carbohydrate - related disturbances in diabetic rats. ASA, given prior to HP, is a potent HSP70 co-inducer and causes additional increase of HSP70 protein level in heart. ASA, given in a combination to HP, have shown more evident protective effects against subsequent intense of stress.

Identification and functional characterization of the sulfakinin and sulfakinin receptor in the Chinese white pine beetle Dendroctonus armandi

The sulfakinin (SK) is an important signal molecule. As a neuromodulator, it mediates a variety of behavioral processes and physiological functions in invertebrates through the interaction with G-protein-coupled receptors (GPCRs). However, there is no report on the functional role of SK in the Chinese white pine beetle, Dendroctonus armandi. We have cloned and characterized SK and SKR genes in the D. armandi and carried out bioinformatics predictions on the basis of the deduced amino acid sequences, which are very similar to those from Dendroctonus ponderosa. The expression levels of the two genes were different between male and female adults, and there were significant changes in different developmental stages, tissues, and between starvation and following re-feeding states. Additionally, RNA-interference (RNAi) using double-stranded RNA to knock down SK and SKR reduced the transcription levels of the target genes and increased their body weight. In parallel, injection of SK caused a significant reduction in body weight and increase in mortality of D. armandi and also led to an increase in trehalose and a decrease in glycogen and free fatty acid. The results show that the SK signal pathway plays a positive and significant role in feeding regulation and provides a potential molecular target for the control of this pest.

Does a Diet Rich in the Bacterium Rhodopirellula rubra Improve Daphnia magna Performance?

In the wild various organisms contribute to daphnids diet. This study, intendeds to evaluate the potential of the concentration of Rhodopirellula rubra as a single or supplementary food source for Daphnia magna. Feeding assays were performed according to standard guidelines for chronic assays (21 days), and life-history parameters and several biomarkers (protein content, oxidative stress, energetic reserves and pigments) were measured. Five food regimens were conducted with 20 individual replicates (A - R. subcapitata; 0.2 - suspension of R. rubra at 0.2 arbitrary units (AU); 0.4 - suspension of R. rubra at 0.4 AU; 0.2+A - suspension of R. rubra at 0.2+alga; 0.2+A-suspension of R. rubra at 0.4 AU + alga). Additionally, the effects of three diets (A, 0.2, and 0.2+A) on the longevity of D. magna were assessed. The five diets showed a different C, N, and carotenoids composition, with an increase in the mixed diets. The results confirmed that the mixed diets improved D. magna life-history parameters. A decrease in glycogen, and the increase of haemoglobin, protein, and gluthione-S-transferase (GST) were observed. Furthermore, D. magna fed with bacterial single diets, presented worsen life history parameters and a decrease in the protein content. An induction of oxidative stress response (increased catalase and GST), and a significant decrease in lipid peroxidation and an accumulation of glycogen and carotenoids were observed. Overall, an increase in the amount of R. rubra provided to D. magna, from 0.2 AU to 0.4 AU, negatively impacted daphnid performance. No significant effects on Daphnia longevity (a 110-day assay) were observed among the three diets tested. However, a significant survival percentage and fertility (cumulative offspring is more than twice) was observed when D. magna was fed with the mixed diet. Results demonstrated that different diets provided a nutritional diversified food to the daphnids that induced differences in D. magna performance. The mixed diets proved to be beneficial (with increase in offspring) on D. magna performance, independently of the bacterial concentration tested. When in single diet, bacterial concentration is not nutritionally sufficient to raise D. magna even when in increased concentration.

Taurine Ameliorates Streptozotocin-Induced Diabetes by Modulating Hepatic Glucose Metabolism and Oxidative Stress in Mice.

Taurine is a sulfated amino acid derivative that plays an important role in maintaining the cell function of the living body. Although taurine has been shown to ameliorate diabetes, its mechanism of action has not yet been fully elucidated. The present study investigated the effects of taurine on diabetes focusing on glucose metabolism and oxidative stress. Type 1 diabetes was induced by the administration of streptozotocin (STZ) to male C57BL/6J mice. Taurine was dissolved in drinking water at 3% (w/v) and allowed to be freely ingested by diabetic mice. The weight and blood glucose levels were measured weekly. After nine weeks, mice were sacrificed and their serum, liver, and kidney were removed and used for biochemical and histological analyses. A microarray analysis was also performed in normal mice. Taurine alleviated STZ-induced hyperglycemia and hyperketonemia, accompanied by the suppression of the decrease in hepatic glycogen and upregulation of the mRNA expression of hepatic glucose transporter GLUT-2. Furthermore, STZ-induced elevation of oxidative stress in the liver and kidney was suppressed by taurine treatment. These results showed that taurine ameliorated diabetes and diabetic complications by improving hepatic glucose metabolism and reducing oxidative stress.

Influence of menstrual cycle on muscle glycogen utilization during high-intensity intermittent exercise until exhaustion in healthy women.

The present study investigated the effects of the menstrual cycle on muscle glycogen and circulating substrates during high-intensity intermittent exercise until exhaustion in healthy women who habitually exercised. In total, 11 women with regular menstrual cycles completed three tests, which comprised the early follicular phase (E-FP), late follicular phase (L-FP), and luteal phase (LP) of the menstrual cycle. High-intensity intermittent exercise until exhaustion was performed on each test day. Evaluation of muscle glycogen concentration by 13C-magnetic resonance spectroscopy and measurement of estradiol, progesterone, blood glucose, lactate, free fatty acids (FFA), and insulin concentrations were conducted before exercise (Pre) and immediately after exercise (Post). Muscle glycogen concentrations from thigh muscles at Pre and Post were not significantly different between menstrual cycle phases (P=0.57). Muscle glycogen decreases by exercise were significantly greater in L-FP (59.0±12.4mM) than in E-FP (48.3±14.4mM, P <0.05). Nonetheless, blood glucose, blood lactate, serum FFA, serum insulin concentrations, and exercise time until exhaustion in E-FP, L-FP, and LP were similar. The study results suggest that although exercise time does not change according to the menstrual cycle, the menstrual cycle influences muscle glycogen utilization during high-intensity intermittent exercise until exhaustion in women with habitual exercise activity. Novelty: This study compared changes in muscle glycogen concentration across the menstrual cycle during high-intensity intermittent exercise until exhaustion using 13C-magnetic resonance spectroscopy. Our results highlight the influence of the menstrual cycle on muscle glycogen during high-intensity intermittent exercise in healthy women.