Insulin Receptor Gene Expression Research Articles

Lactobacillus casei-fermented Amomum xanthioides ameliorates metabolic dysfunction in high-fat diet-induced obese mice.

Amomum xanthioides (AX) has been used as an edible herbal medicine to treat digestive system disorders in Asia. Additionally, Lactobacillus casei is a well-known probiotic commonly used in fermentation processes as a starter. The current study aimed to investigate the potential of Lactobacillus casei-fermented Amomum xanthioides (LAX) in alleviating metabolic disorders induced by high-fat diet (HFD) in a mouse model. LAX significantly reduced the body and fat weight, outperforming AX, yet without suppressing appetite. LAX also markedly ameliorated excessive lipid accumulation and reduced inflammatory cytokine (IL-6) levels in serum superior to AX in association with UCP1 activation and adiponectin elevation. Furthermore, LAX noticeably improved the levels of fasting blood glucose, serum insulin, and HOMA-IR through positive regulation of glucose transporters (GLUT2, GLUT4), and insulin receptor gene expression. In conclusion, the fermentation of AX demonstrates a pronounced mitigation of overnutrition-induced metabolic dysfunction, including hyperlipidemia, hyperglycemia, hyperinsulinemia, and obesity, compared to non-fermented AX. Consequently, we proposed that the fermentation of AX holds promise as a potential candidate for effectively ameliorating metabolic disorders.

Effects of dietary soy content on cerebral artery function and behavior in ovariectomized female mice.

As females age, they transition through menopause, experiencing a decrease in estrogen and an increase in cardiovascular and neurodegenerative disease risk. Most standard rodent chows contain phytoestrogen-rich soybean meal, which can mimic the effects of estrogen. Understanding the impact of this soybean meal on vascular outcomes is crucial to proper experimental design. Thus, this study aimed to compare the effects of standard and soy-free chows on cerebral artery endothelial function and cognitive function in ovariectomized mice. Young female C57Bl/6J mice (n = 43; ∼6 mo) were randomly assigned to three groups: sham, ovariectomy (OVX), or ovariectomy on a diet containing soy (OVX + Soy). In posterior cerebral arteries, the OVX mice had a 27% lower maximal response to insulin compared with the sham mice. The OVX + Soy mice had a 27% greater maximal vasodilation to insulin compared with the OVX mice and there were no differences in vasodilation between the OVX + Soy and sham groups. The group differences in vasodilation were mediated by differences in nitric oxide bioavailability. The OVX + Soy mice also had greater insulin receptor gene expression in cerebral arteries compared with the OVX mice. However, no differences in aortic or cerebral artery stiffness were observed between groups. Interestingly, the OVX + Soy group scored better on nesting behavior compared with both sham and OVX groups. In summary, we found that ovariectomy impairs insulin-mediated vasodilation in cerebral arteries, but a diet containing soy mitigates these effects. These findings highlight the importance of considering dietary soy when performing vascular and behavioral tests in mice, particularly in females.NEW & NOTEWORTHY To properly design experiments, we must consider how variables like diet impact our outcomes, particularly the effects of soy on females. We found that cerebral artery vasodilation in response to insulin was impaired in ovariectomized female mice compared with intact shams. However, ovariectomized mice fed a soy diet had a preserved cerebral artery insulin-mediated vasodilation. These results highlight that the effects of diet on vascular function may explain inconsistencies found between studies.

Tetrahydropalmatine from medicinal plants activates human glucokinase to regulate glucose homeostasis.

Many synthetic glucokinase activators (GKAs), modulating glucokinase (GK), an important therapeutic target in diabetes have failed to clear clinical trials. In this study, an in silico structural similarity search with differing scaffolds of reference GKAs have been used to identify derivatives from natural product databases. Ten molecules with good binding score and similar interactions to that in the co-crystallized GK as well good activation against recombinant human GK experimentally were identified. Tetrahydropalmatine, an alkaloid present in formulations and drugs from medicinal plants, has not been explored as an antidiabetic agent and no information regarding its mechanism of action or GK activation exists. Tetrahydropalmatine activates GK with EC50 value of 71.7±17.9μM while lowering the S0.5 (7.1mM) and increasing Vmax (9.22μM/min) as compared to control without activator (S0.5=10.37mM; Vmax=4.8μM/min). Kinetic data (α and β values) suggests it to act as mixed, nonessential type activator. Using microscale thermophoresis, Kd values of 3.8μM suggests a good affinity for GK. In HepG2 cell line, the compound potentiated the uptake of glucose and maintained glucose homeostasis by increasing the expression of GK, glycogen synthase, and insulin receptor genes and lowering the expression of glucokinase regulatory protein (GKRP) and glucagon. Tetrahydropalmatine at low concentrations could elicit a good response by reducing expression of GKRP, increasing expression of GK while also activating it. Thus, it could be used alone or in combination as therapeutic drug as it could effectively modulate GK and alter glucose homeostasis.

SAT072 Choline Deprivation Aggravates Hyperglycemia And Fatty Liver In Non-obese Streptozocin-induced Diabetic Rats

Abstract Disclosure: C. Liapi: None. A. Kyriakaki: None. H. Al Humadi: None. R. Al-Saigh1: None. A. Al Humadi: None. A. Lazaris: None. Background: Choline deprivation (CD) is an established model of steatohepatitis. There is a strong association between non-alcoholic fatty liver disease and diabetes mellitus that has a significant impact on the global health system. The combined state of CD and diabetes can resemble common cases in clinical practice including parenteral nutrition, pregnancy, chronic liver disease malnutrition and/ or alcoholism in diabetic individuals. The aim of this study was to investigate the effects of choline deprivation on glycemic control, insulin signaling pathway and lipid metabolism in non-obese streptozocin-induced diabetic rats. Methods: Thirty-two male adult Wistar rats were divided into four groups; control, diabetes (DM), choline-deprived diet (CDD), and combined group (DM+CDD); DM was induced by intraperitoneal streptozotocin administration. Body weight, fasting blood glucose and plasma insulin levels, lipid profile, liver biochemistry, liver histopathology and gene expression of insulin receptor (IR), insulin receptor substrate-1 (IRS-1), glucose transporters 2 & 4 (GLUT-2 & -4) in hepatic tissue, were assessed. Results: The combination group (CDD+DM) showed a significant increase in blood glucose associated with a significant decrease in plasma insulin level and evidence of dyslipidemia with a significant increase in liver enzymes, histopathology showed extensive micro- and macrovesicular steatosis and a significant decrease in weight gain versus the control, CDD and DM group. A significant increase was observed in gene expression of IR, IRS-1, GLUT-2, and GLUT-4 in all the experimental groups versus the control. Conclusion: The combination of choline deficiency and diabetes has drawn some new scenarios on insulin and some hepatic metabolic pathways: (i) plasma insulin resistance with progressive hyperglycemia and hyperlipidemia.(ii) attenuation of hepatic insulin resistance or sensitization of insulin signaling pathways in the liver, due to the hepatotoxic effects of choline deficiency that could ultimately simulate features of the metabolic syndrome, and (iii) experimentally simulation of metabolic conditions seem to act synergistically, leading to poor glycemic control along with aggravation of hepatic steatosis. Presentation: Saturday, June 17, 2023

THU157 Epigenetic Regulation Of Genes Involved In The Signaling Cascade Of The GH Axis - IGF1 And Insulin. Implication In Children Postnatal Growth

Abstract Disclosure: L. Zoff: None. F. Garcia: None. G. Aschettino: None. G. Veneruzzo: None. M.C. Mattone: None. N. Perez Garrido: None. M. Juanes: None. N.I. Saraco: None. C. Alonso: None. G. Guercio: None. A. Belgorosky: None. M.S. Baquedano: None. Growth is influenced by genetic, nutritional, environmental, and hormonal factors, but it proceeds in a predictable pattern characterized by a constant growth deceleration between childhood and adolescence. This growth deceleration is coordinated in tissues and organs in order to maintain body proportions. Growth hormone (GH)/ insulin-like growth factor type 1 (IGF1) axis and insulin are crucial stimulators of growth, cell proliferation and metabolism. However, their levels do not change with age in a pattern that would explain the prepubertal decline in growth rate. DNA methylation represents a fundamental epigenetic mark that is associated with transcriptional repression during development. We hypothesize that the postnatal growth pattern could be orchestrated by epigenetic mechanisms. In order to analyze age related physiological changes, we evaluated promoter methylation in the GHR, IGF1R and INSR genes in peripheral blood from 40 healthy children of both sexes (females (F) n=21 and males (M) n=19), between 3 and 15 years old by using targeted deep-amplicon bisulfite sequencing on a MiSeq system. Sequencing libraries of 4 promoter CpG rich regions for GHR, 3 for IGF1R and 5 for INSR (104, 103 and 141 CpG sites, respectively) were analyzed for mean methylation values of all CpG sites using amplikyzer2 software. The results would suggest a sexual dimorphism in the epigenetic regulation of GH, IGF1 and insulin receptors gene expression. A significant negative correlation between GHR methylation and age was observed in both sexes (Multiple Spearman correlation, p<0.05), but in different GHR promoter regions. Specifically, a decrease in themethylation levels with age were detected in CpG-8, CpG+183 and CpG+243 in F; and in CpG+343, CpG+346, CpG+385, CpG+391, CpG+407 and CpG+487 in M. In contrast, in the IGF1R promoter region, a positive correlation was observed exclusively in F, between mean methylation levels and age in CpG-51, CpG-43, CpG-41, CpG-23, CpG-17, CpG-15, CpG-13, CpG-11, and CpG-9, p<0.05. Male-specific positive correlation between INSR promotermethylation values and age were found in CpG-768, CpG+10, CpG+31, CpG+87, CpG+95, CpG+163, CpG+199, CpG+206, CpG+238, CpG+700, CpG+815 and CpG+900, p<0.05.Taking together, our findings are in agreement with the hypothesis that age-associated DNA promoter methylation changes could be involved in the physiological growth pattern. Finally, the observed sexual dimorphism suggests age- and sex-dependent regulatory mechanisms for normal growth. Presentation: Thursday, June 15, 2023

Sex-specific effect of P2Y2 purinergic receptor on glucose metabolism during acute inflammation.

The sex of an animal impacts glucose sensitivity, but little information is available regarding the mechanisms causing that difference, especially during acute inflammation. We examined sex-specific differences in the role of the P2Y2 receptor (P2Y2R) in glucose flux with and without LPS challenge. Male and female wild-type and P2Y2R knockout mice (P2Y2R-/-) were injected with LPS or saline and glucose tolerance tests (GTT) were performed. P2Y2R, insulin receptor, and GLUT4 transporter gene expression was also evaluated. Female mice had reduced fasting plasma glucose and females had reduced glucose excursion times compared to male mice during GTT. P2Y2R-/- males had significantly decreased glucose flux throughout the GTT as compared to all female mice. Acute inflammation reduced fasting plasma glucose and the GTT area under the curve in both sexes. While both wild-type and P2Y2R-/- male animals displayed reduced fasting glucose in LPS treatment, female mice did not have significant difference in glucose tolerance, suggesting that the effects of P2Y2R are specific to male mice, even under inflammatory conditions. Overall, we conclude that the role for the purinergic receptor, P2Y2R, in regulating glucose metabolism is minimal in females but plays a large role in male mice, particularly in the acute inflammatory state.

Vitamin D and rosuvastatin alleviate type-II diabetes-induced cognitive dysfunction by modulating neuroinflammation and canonical/noncanonical Wnt/β-catenin signaling.

Type-II diabetes mellitus (T2DM) is a major risk factor for cognitive impairment. Protecting the brain environment against inflammation, and neurodegeneration, as well as preservation of the BBB veracity through modulating the crosstalk between insulin/AKT/GSK-3β and Wnt/β-catenin signaling, might introduce novel therapeutic targets. This study aimed at exploring the possible neuroprotective potential of vitamin D3 (VitD) and/or rosuvastatin (RSV) in T2DM-induced cognitive deficits. T2DM was induced by a high-fat sucrose diet and a single streptozotocin (STZ) dose. Diabetic rats were allocated into a diabetic control and three groups treated with RSV (15 mg/kg/day, PO), VitD (500 IU/kg/day, PO), or their combination. Administration of VitD and/or RSV mitigated T2DM-induced metabolic abnormalities and restored the balance between the anti-inflammatory, IL 27 and the proinflammatory, IL 23 levels in the hippocampus. In addition, they markedly activated both the canonical and noncanonical Wnt/β-catenin cassettes with stimulation of their downstream molecular targets. VitD and/or RSV upregulated insulin and α7 nicotinic acetylcholine (α7nACh) receptors gene expression, as well as blood-brain barrier integrity markers including Annexin A1, claudin 3, and VE-cadherin. Also, they obliterated hippocampal ApoE-4 content, Tau hyperphosphorylation, and Aβ deposition. These biochemical changes were reflected as improved behavioral performance in Morris water maze and novel object recognition tests and restored hippocampal histological profile. The current findings have accentuated the neuroprotective potential of VitD and RSV and provide new incentives to expand their use in T2DM-induced cognitive and memory decline. This study also suggests a superior benefit of combining both treatments over either drug alone.

RNA interference knockdown of insulin receptor inhibits ovarian development in Chilo suppressalis.

The nutritional signaling pathway regulates an insect's size, development, and lifespan, as well as playing a vital role in reproduction. The insulin/insulin-like growth factor signaling (IIS) pathway plays a key role in the nutrition signaling pathway. As an integral component of the IIS pathway, insulin receptor (InR), a receptor tyrosine kinase, plays a role in the insulin pathway by controlling reproduction in many insect species. However, the precise molecular function of InR in non-model insect reproduction is poorly understood. In our study, Chilo suppressalis, a well-known rice pest, was used as a molecular system to determine the role of InR in insect reproduction. Sequencing the InR gene of C. suppressalis, comparing the amino acid sequence-specific structure, and constructing a phylogenetic tree revealed that this gene has four main domains: ligand binding L domain, Furin-like region, fibronectin type III domains, and Tyrosine kinase catalytic domain, which were all highly conserved in insects. By characterizing the spatiotemporal expression profile of InR in different developmental stages and tissues, we found that InR gene expression was highest on the 3-day old in female pupae, 6th instar larvae, and fat body on the 6-day old in female pupae. InR gene expression may promote the molting and pupation of larvae and play a role in reproduction in the fat body. Furthermore, the RNA interference knockdown of InR dramatically reduced yolk deposition and blocked oocyte maturation. After suppression of InR, the expression of several other genes fluctuated to varying degrees. In conclusion, InR is vital to reproduction and is expected to become a new target for pest management.

Endometrial Expression of Insulin Signaling Pathway Genes in Pregnancy Leading to Abortion under 20 Weeks in Infertile Women: A Case-Control Study.

Impaired expression of genes which act on hormone signaling pathways is one of the factors affecting miscarriage. In this study, the expression levels of insulin receptor (INSR) and insulin receptor substrates-1 (IRS-1) genes in endometrial tissue of infertile women and fertile women with miscarriage in less than twenty weeks gestation for unknown reasons were evaluated. In this case-control study, forty-two fertile women with children and 42 infertile women, who underwent in vitro fertilization (IVF), were selected. Both groups had abortions under twenty weeks gestation for unknown reasons. The endometrial tissue of all patients was prepared to evaluate the expression of INSR and IRS-1 genes by quantitative real-time polymerase chain reaction (PCR) method after RNA extraction. There was a statistically significant relationship between the expressions of INSR and IRS-1 genes in the endometrial tissue of the infertile women compared with the fertile women (P=0.002 and P=0.008, respectively). The expression level of genes was decreased in both groups by age and increasing body mass index (BMI). Comparison of genes expression levels in healthy and diabetic participants in each group showed a significant difference (P<0.0001), but no meaningful difference was indicated between diabetic infertile and fertile groups in terms of gene expression. INSR gene expression levels showed an increase in the fertile group in the second 10 weeks and a decrease in IRS-1 gene expression. But in the infertile group, both genes showed a slight increase in expression. It seems a decreased expression of insulin signaling pathway genes in the endometrial tissue of infertile women can be one of reasons for unspecified abortion. These genes may be strong molecular markers for infertility.

Changes in tear glucose and insulin concentrations following an oral glucose tolerance test

ABSTRACT Clinical relevance Tear glucose and insulin are responsible for the health of the ocular surface; thus, it is important for clinicians to detect the tear glucose and insulin using point-of-care methods. Aim To determine if changes in blood glucose and insulin levels following an oral glucose tolerance test are reflected in the tears and to test the association between gene expression and tear insulin and glucose. Methods Twenty healthy young adults were enrolled. Basal tears and peripheral blood samples were collected to assess glucose and insulin using a point-of-care glucometer and ELISA assays in fasted subjects, and 1.5 and 3 h after an oral glucose challenge. Conjunctival impression cytology was collected to determine gene expression of insulin receptor (INSR) and glucose transporters (GLUT1 and GLUT4). Changes were examined using non-parametric one-way ANOVA. Spearman tests were conducted to examine associations between variables. Results Glucose and insulin levels increased 1.5 h after oral glucose in both blood (P < 0.001) and tears (P < 0.049) and returned to near baseline values after 3 h. There was a positive correlation between glucose levels in the blood and tears (rho = 0.57, P < 0.001), but not between blood and tear insulin levels (P = 0.18). Glucose and insulin levels in tears were correlated (rho = 0.32, P = 0.048). Tear glucose concentration at 1.5 h after oral glucose was associated with INSR expression (rho = 0.49, P = 0.03), and there was a trend with GLUT1 (P = 0.06) but not GLUT4. Conclusion Tear glucose reflected blood glucose levels but this correspondence was not observed for insulin. Further studies are required to determine the role of glucose and insulin on the ocular surface in both health and diabetes.

α7nAChR activation protects against oxidative stress, neuroinflammation and central insulin resistance in ICV-STZ induced sporadic Alzheimer's disease

Central insulin resistance is considered as one of the pathological hallmarks of Alzheimer's disease (AD), similar to formation of amyloid plaques and neurofibrillary tangles (NFT). Activation of α7nAChR by GTS-21 has been indicated to reverse peripheral insulin resistance and exert neuroprotection. Therefore, the aim of the present study was to determine the effect of α7nAChR agonist (GTS-21) on intracerebroventricular administration of streptozotocin (ICV-STZ)-induced oxidative stress, neuroinflammation, cholinergic dysfunction, central insulin resistance and cognitive deficits. GTS-21 (1, 4 and 8 mg/kg; i.p.) was administered for 21 days following bilateral ICV-STZ administration (3 mg/kg) in C57BL/6 mice. Neurobehavioral assessments were performed using Morris water maze (MWM) and novel object recognition (NOR). Inflammatory markers (TNF-α, IL-6 and IL-1β) were determined using ELISA. Oxido-nitrosative stress (GSH, MDA and nitrite) and cholinergic activity (acetylcholine esterase and choline acetyltransferase) were estimated in the cortex and hippocampus through biochemical methods. Gene expression of insulin receptor (IR), IRS1, IRS2, BACE1, APP, PI3-K, AKT and GSK3β were determined by q-RT-PCR. ICV-STZ administration induced memory impairment, increased oxidative stress and neuroinflammation, and caused cholinergic dysfunction. Our results demonstrated that activation of α7nAChR by GTS-21 treatment improved memory in MWM and NOR test. Moreover, GTS-21 treatment significantly decreased oxido-nitrosative stress, inflammatory markers and cholinergic dysfunction in cortex and hippocampus. Finally, GTS-21 treatment restored ICV-STZ induced downregulation of IR, IRS1, IRS2, PI3-k, Akt and attenuated GSK3β, APP and BACE-1 indicating improved insulin signalling. Therefore, activation of α7nAChR through GTS-21 might be the potential target for the amelioration of central insulin resistance induced AD.

Molecular docking and mouse modeling suggest CMKLR1 and INSR as targets for improving PCOS phenotypes by minocycline.

Polycystic ovary syndrome (PCOS) is the most common cause of women's infertility. Some inflammatory pathways play a pivotal role in the pathogenesis of PCOS. This study aimed to investigate the possible beneficial effects of minocycline on chemokine-like receptor 1 (CMKLR1) and Insulin Receptor (INSR) in a PCOS model. A molecular docking study was implemented using Molecular Operating Environment (MOE) software. The PCOS was induced in NMRI mice (mean body weight 14.47±0.23) by 28 days estradiol valerate injection (2 mg/kg/day). The mice were then divided into six groups (n=8 per group, mean body weight 17.77± 0.26): control (received normal saline), PCOS model, control for minocycline, minocycline treated PCOS (50 mg/kg), letrozole treated PCOS (0.5 mg/kg), and metformin-treated PCOS (300 mg/kg). Serum FSH, LH, estradiol (E2), and testosterone were detected by ELISA. The ovarian tissues were stained by hematoxylin and eosin. The CMKLR1 and INSR expression levels were determined by Real-time-PCR. The molecular docking studies showed scores of -10.92 and -9.30 kcal/mol, respectively, for minocycline with CMKLR1 and INSR. Estradiol valerate treatment led to a significant increase in E2, graffian follicle, and decrease in corpus luteum (CL) numbers (P<0.05), while minocycline treatment improved these PCOS features. The minocycline treatment significantly decreased the CMKLR1 expression and increased the INSR expression (P<0.05) while the CMKLR1 expression was increased in PCOS model. Minocycline may improve ovulation in PCOS model by returning E2 to a normal level and increasing CL number (ovulation signs). These beneficial outcomes may be related to the changes in CMKLR1 and INSR gene expression involved in glucose metabolism and inflammation.

The effects of different carbon sources on growth, tyrosine kinase activity and gene expression of insulin receptor 1 in GIFT tilapia

A feeding trial was conducted to evaluate the effects of different sugar sources on growth performance, serum biochemistry, immunity, insulin receptor 1 and tyrosine kinase activity of GIFT tilapia. Four hundred and eighty fish with specifications of 31.70±0.68 g were selected and placed in 16 aquariums. The experiment was divided into four treatment with four replicates of thirty fish per tank. After 50 days of feeding, the results were as follows: From the indexes of final average weight, weight gain rate and specific growth rate, the growth performance was sucrose, glucose, starch and dextrin group in turn, and the sucrose group performed best (P&lt;0.05). The activcities of acid phosphotase, alkaline phosphotase, superoxide dismutase and lysozyme in sucrose group were significantly higher than that of the other three groups (P&lt;0.05). The serum glucose level of sucrose group and glucose group is significantly higher than that of dextrin group and starch group (P &lt; 0.05). In terms of liver glycogen level, the content of sucrose group was significantly higher than that of dextrin group and starch group (P &lt; 0.05). In terms of muscle glycogen level, the content of sucrose group was the highest and that of starch group was the lowest. The tyrosine kinase activity of glucose group was the highest and significantly different from dextrin group (P&lt; 0.05). The tyrosine kinase activity in muscle was always higher than that in liver (P &lt; 0.05). The IR-1 mRNA in starch group and dextrin group was significantly higher than that in sucrose group. Different sugar source diets had a significant effect on the expression of IR-1 mRNA in the muscle of tilapia. In conclusion, compared with dextrin and starch, sucrose and glucose can be better utilized by GIFT tilapia and show good growth performance. Key words: GIFT tilapia; Carbohydrates; Growth; Immunity; Insulin Receptor 1; Tyrosine Kinase

Single-Cell Analysis Identify Transcription Factor BACH1 as a Master Regulator Gene in Vascular Cells During Aging.

Vascular aging is a potent driver of cardiovascular and cerebrovascular diseases. Vascular aging features cellular and functional changes, while its molecular mechanisms and the cell heterogeneity are poorly understood. This study aims to 1) explore the cellular and molecular properties of aged cardiac vasculature in monkey and mouse and 2) demonstrate the role of transcription factor BACH1 in the regulation of endothelial cell (EC) senescence and its mechanisms. Here we analyzed published single-cell RNA sequencing (scRNA-seq) data from monkey coronary arteries and aortic arches and mouse hearts. We revealed that the gene expression of YAP1, insulin receptor, and VEGF receptor 2 was downregulated in both aged ECs of coronary arteries’ of monkey and aged cardiac capillary ECs of mouse, and proliferation-related cardiac capillary ECs were significantly decreased in aged mouse. Increased interaction of ECs and immunocytes was observed in aged vasculature of both monkey and mouse. Gene regulatory network analysis identified BACH1 as a master regulator of aging-related genes in both coronary and aorta ECs of monkey and cardiac ECs of mouse. The expression of BACH1 was upregulated in aged cardiac ECs and aortas of mouse. BACH1 aggravated endothelial cell senescence under oxidative stress. Mechanistically, BACH1 occupied at regions of open chromatin and bound to CDKN1A (encoding for P21) gene enhancers, activating its transcription in senescent human umbilical vein endothelial cells (HUVECs). Thus, these findings demonstrate that BACH1 plays an important role in endothelial cell senescence and vascular aging.

Effects of different chromium sources on growth performance, serum biochemical, hepatopancreas glycometabolism enzymes activities, IR, GLUT2 and SGLT1 gene expression of common carp ( Cyprinus carpio )

A 60-day feeding trial was conducted to evaluate the effects of different chromium sources on the common carp. Four diets (32.2% crude protein and 6% lipids of dry matter) were formulated to add chromium oxide (Cr2O3), chromium picolinate (CrPic) and chromium methionine (CrMet) with 2 mg/kg Cr3+, respectively, and one basal diet. Each diet was randomly assigned to triplicate groups of 60 juvenile common carp (approximately 40.95 ± 4.80 g). The results indicated that fish fed CrMet diets had significantly higher weight gain, specific growth rate and feed efficiency than other groups (p < 0.05). No significant differences in the whole body compositions except the lipid content significantly increased in CrMet diets (p < 0.05). Fish that were fed chromium diets had significantly higher lactic dehydrogenase and creatine kinase in serum, succinic acid dehydrogenase and lactic acid in muscle, pyruvate kinase and glycogen synthase in hepatopancreas, lower glucose concentration and phosphoenolpyruvate carboxykinase activities in hepatopancreas than those given the basal diet (p < 0.05). Insulin receptor (IR) in serum, IR gene expression in hepatopancreas and sodium-dependent glucose transporter 1 (SGLT1) in intestinal was increased (p < 0.05), while the cortisol decreased significantly in the dietary of CrMet or CrPic (p < 0.05). CrMet supplementation also increased HK activities, up-regulated glucose transporter 2 (GLUT2) in hepatopancreas (p < 0.05). In conclusion, dietary addition of CrMet improved growth performance, adjusted glycometabolism enzyme activities, IR, GLUT2 and SGLT1 gene expression and had a significant impact on the carbohydrate utilization of juvenile common carp fed high corn diets compared with CrPic and Cr2O3.

Feeding Saccharomyces cerevisiae fermentation products lessens the severity of a viral-bacterial coinfection in preweaned calves.

We have previously reported that supplementation with Saccharomyces cerevisiae fermentation products (SCFP) ameliorates clinical signs and lung pathology following experimental bovine respiratory syncytial virus (BRSV) infection in preweaned dairy calves. The objectives of this study were to determine the effect of SCFP supplementation on the metabolic and endocrine responses, and disease outcome of a viral–bacterial coinfection in preweaned calves. Twenty-seven, 1- to 2-d-old Holstein-Angus cross calves were enrolled in the study; one SCFP calf was removed from the trial during the pre-challenge phase due to complications from nephritis. Calves were assigned to two treatment groups: control or SCFP-treated, base milk replacer with 1 g/d SCFP (Smartcare, soluble formula) and calf starter top dressed with 5 g/d SCFP (NutriTek, insoluble formula). Calves were infected with BRSV on day 21, followed 6 d later by intratracheal inoculation with Pasteurella multocida (PM). Calves were euthanized on day 10 post-viral infection. Calves receiving SCFP had reduced thoracic ultrasonography scores on day 7 post-viral infection (P = 0.03) and a tendency toward reduced scores on day 10 post-viral infection (P = 0.09). Calves receiving SCFP also had less severe lung pathology scores at necropsy (P = 0.06). No differences between treatments were observed in lung viral loads (P = 0.48) or bacterial lung recovery (P = 0.34); however, there was a distinction in the lung location for PM recovery, with PM isolated more frequently from the cranial lobes in SCFP-treated calves, but more frequently from the caudal lobes of control calves. Calves treated with SCFP tended (P = 0.07) to have higher serum IL-6 concentrations following the coinfection. Calves treated with SCFP had lower concentrations of serum nonesterified fatty acids and beta-hydroxybutyric acid compared with controls following experimental challenge (P = 0.03 and P = 0.08, respectively), suggesting metabolic changes favoring growth and development. There were no differences between groups in gene expression of insulin receptor, insulin-like growth factor 1 (IGF-1), IGF-1 receptor (IGF-1R), growth hormone receptor, or haptoglobin in the liver. Results from this study suggest that supplementing with SCFP may moderate the impact of a respiratory viral–bacterial coinfection on preweaned calves through metabolic and immune modifications.

Epigenetic Programming Induces Changes in Metabolic and Gene Expression and Reverses the Effects of Ang‐II Infusion in Male Mice

Cardiometabolic diseases are highly prevalent chronic illnesses associated with high risk morbidities. Maternal epigenetic programming modulates gene expression in offspring thus affecting their disease susceptibility later in life. The renin-angiotensin system (RAS) contributes to cardiometabolic homeostasis however, its over-activation is associated with cardiometabolic dysfunctions. Previously, we showed that perinatal exposure to high fat diet (HFD) leads to elevated BP, heart rate, fasting blood glucose (FBG) and weight gain in addition to elevated brain AT1R and ADAM17 gene expression exclusively in males. We hypothesize that perinatal HFD exposure leads to changes in RAS gene expression in peripheral tissues and these changes could be accentuated by low dose Angiotensin-II (Ang-II) revealing a stronger cardiometabolic dysfunction. C57BL6/J dams were fed a HFD or regular diet (RD) for 1 month and mated with RD-fed males. After weaning, offspring were put on RD resulting in two groups; HFD-RD (programmed) and RD-RD (control). At 3 months, offspring underwent 24 h BP recording (telemetry) and glucose tolerance test (GTT). Half of the mice in each group were then implanted with an osmotic pump filled with Ang-II (200 ng/kg/min/2 weeks) resulting in 4 groups; HFD-RD, RD-RD, HFD-RD+Ang-II, RD-RD+Ang-II. BP (24 h) was recorded weekly and GTT was repeated after the 2nd week for the Ang-II-treated mice. For all groups, Liver, muscle and adipose tissues were harvested and selected genes expression was quantified using qPCR. HFD-RD males exhibited higher FBG than RD-RD males (172.7 ±6 vs. 145.2 ±5 mg/dL, p=0.01) and higher blood glucose at 15 min (387.8 ±17 vs. 303.4 ±30 mg/dL, p=0.04). Surprisingly, only HFD-RD+Ang-II males showed lowered FBG level compared to HFD-RD males (139.7 ±8 mg/dL vs. 172.7 ±6, p=0.007) and at 15 min (279.8 ±19 mg/dL vs. 387.8 ±17, p=0.006). Interestingly, no metabolic changes were seen in females in any of the groups. In addition, Ang-II infusion had no effect on hemodynamic parameters in treated groups. Regarding gene expression, HFD-RD showed upregulation of insulin receptor (p=0.0019), ACE2 (p=0.008), and ADAM17 (p=0.04) in the liver compared to RD-RD. Conversely, in HFD-RD+Ang-II, insulin receptor and ACE2 were downregulated in the liver (p<0.0001) relative to HFD-RD. In muscle tissue, while ADAM17 was upregulated in RD-RD+Ang-II (p=0.039), there was no change in ADAM17 expression in HFD-RD+Ang-II. Additionally, AT1 receptor was strongly upregulated in RD-RD+Ang-II (p<0.0001) with a slight upregulation in HFD-RD+Ang-II (p=0.03). We conclude that perinatal exposure to HFD leads to a pre-diabetic state evident by elevated FBG, disturbed first phase insulin secretion, changes in insulin receptor and RAS gene expression exclusively in male mice. This programming reverses the effects of Ang-II, possibly switching signaling towards another angiotensin receptor involved in a protective mechanism.

A Neonatal Mild Defect in Brain Insulin Signaling Predisposes a Subclinical Model of Sporadic Alzheimer's to Develop the Disease.

Brain insulin system dysfunction has been proposed as a key player in the pathogenesis of sporadic Alzheimer's disease (sAD). Given this fact, an adult rat model for sAD has been developed by intracerebroventricular injection of a subdiabetogenic streptozotocin dosage (icv-STZ). A low dose of icv-STZ in adult rats leads to a subclinical model of Alzheimer's disease. According to the brain developmental origin for sAD occurrence, the present study evaluated the effect of neonatal injection of icv-STZ on the development and progression of Alzheimer's disease later in the adult animals treated with a low dose of icv-STZ. Although no alteration was observed in the rats receiving an adult low dose of icv-STZ, these animals displayed cognitive deficits if they were also treated neonatally with icv-STZ. These impairments were associated with altered gene expression of insulin receptor, tau and choline acetyltransferase, along with increased astrocyte and dark neuron densities in the hippocampus. This study highlights neonatal brain insulin system dysfunction in the programming of brain insulin signaling sensitivity and provides more evidence for the developmental origin of sAD.

The Effect of Swimming Training and Cinnamon Consumption on the Gene Expression of GLUT4 and Insulin Receptor in the Brown Adipose Tissue of Diabetic Rats

Background: The effect of training on the gene expression of GLUT4 and insulin receptor (IR) has been investigated in some studies, but the simultaneous effect of swimming training along with cinnamon consumption is unknown. Objective: This study aimed to examine the effect of six weeks of swimming training with cinnamon consumption on the gene expression of GLUT4 and IR in the brown adipose tissue of diabetic rats. Methods: In this experimental study, 28 diabetic rats were randomly divided into four groups of seven animals, including 1- control (C), 2- cinnamon (Ci), 3- swimming (S), and 4- swimming plus cinnamon (S + Ci). Rats in groups 3 and 4 trained for six weeks and five sessions. Groups 2 and 4 received 200 mg/kg/day. Data were analyzed using one-way analysis of variance and Tukey’s post hoc test at the level of P ≤ 0.05. Results: The gene expression of GLUT4 and IR in the S, Ci, and S + Ci groups was significantly (P = 0.001) higher than the control group. Also, the gene expression of GLUT4 and IR in the S group was significantly (P = 0.001) higher than the Ci and S + Ci groups. Conclusion: Swimming training and cinnamon consumption and their simultaneous implementation had a significant effect on increasing the gene expression of GLUT4 and IR in the brown adipose tissue of diabetic rats. On the other hand, swimming training alone had a greater effect than cinnamon consumption and swimming plus cinnamon consumption.

Benzyl Butyl Phthalate Induced Early lncRNA H19 Regulation in C3H10T1/2 Stem Cell Line.

Exposure to endocrine-disrupting chemicals used in plastic manufacturing may contribute to the current obesity and diabetes epidemic. Our previous study demonstrated that benzyl butyl phthalate (BBP) induced adipogenesis in the C3H10T1/2 stem cell line. Here we investigated if BBP deregulated long noncoding RNA H19 and its downstream pathway and whether BBP plays a role in the insulin signaling pathway during adipocyte diiferentiation. Cells treated with an 8 day BBP regimen showed that H19 expression was decreased at day 2 with 50 μM BBP exposure (p < 0.05). However, no significant changes were observed from day 4 to day 8. Expression of miRNA-103/107, H19 regulated miRNAs, was upregulated at day 2 (p < 0.05) but not from day 4 to day 8. Similarly, expression of the let-7 family members (a, b, c, d, f, and g) was also significantly increased at day 2 (p < 0.05 or p < 0.01), except for let-7e. Both let-7 and miRNA-103/107 are targets of H19 and play roles in insulin signaling. Insulin receptor substrate (IRS)-1, one of the key insulin signal transduction regulators, was significantly downregulated from day 2 to day 8 (p < 0.05). Gene expression of insulin receptor (IR) and IRS-2 were not altered by BBP exposure. The ratio of IRS1/IRS2 was significantly decreased from day 2 to day 8. On day 4, phospho-Akt protein expression was significantly decreased (p < 0.05). In conclusion, BBP exposure may lead to metabolic dysregulation by altering vital epigenetic regulators such as lncRNA H19 and its target microRNAs at an earlier stage, which further regulates insulin signaling.