GLUT4 Expression Research Articles

Effect of RNF113A deficiency on oxidative stress-induced NRF2 pathway

ABSTRACT The ring finger protein 113A (RNF113A) serves as an E3 ubiquitin ligase and a subunit of the spliceosome. Mutations in the RNF113A gene are associated with X-linked trichothiodystrophy (TTD). However, the cellular roles of RNF113A remain largely unknown. In this study, we performed transcriptome profiling of RNF113A knockout (KO) HeLa cells using RNA sequencing and revealed the upregulation of NRF2 pathway-associated genes. Further analysis confirmed that the KO of RNF113A promotes nuclear localization of the NRF2 protein and elevates the mRNA levels of NRF2 target genes. RNF113A KO cells showed high levels of intracellular reactive oxygen species (ROS) and decreased resistance to cell death following H2O2 treatment. Additionally, RNF113A KO cells more sensitively formed stress granules (SGs) under arsenite-induced oxidative stress. Moreover, RNF113A KO cells exhibited a decrease in glutathione levels, which could be attributed to a reduction in GLUT1 expression levels, leading to decreased glucose uptake reactions and lower intracellular glucose levels. These alterations potentially caused a reduction in ROS scavenging activity. Taken together, our findings suggest that the loss of RNF113A promotes oxidative stress-mediated activation of the NRF2 pathway, providing novel insights into RNF113A-associated human diseases.

Regulation and Role of Adiponectin Secretion in Rat Ovarian Granulosa Cells.

Adiponectin is an important adipokine involved in glucose and lipid metabolism, but its secretion and potential role in regulating glucose utilization during ovarian development remains unclear. This study aims to investigate the mechanism and effects of follicle-stimulating hormones (FSHs) on adiponectin secretion and its following impact on glucose transport in the granulosa cells of rat ovaries. A range of experimental techniques were utilized to test our research, including immunoblotting, immunohistochemistry, immunofluorescence, ELISA, histological staining, real-time quantitative PCR, and transcriptome analysis. The immunohistochemistry results indicated that adiponectin was primarily located in the granulosa cells of rat ovaries. In primary granulosa cells cultured in vitro, both Western blot and immunofluorescence assays demonstrated that FSH significantly induced adiponectin secretion within 2 h of incubation, primarily via the PKA signaling pathway rather than the PI3K/AKT pathway. Concurrently, the addition of the AdipoR1/AdipoR2 dual agonist AdipoRon to the culture medium significantly stimulated the protein expression of GLUT1 in rat granulosa cells, resulting in enhanced glucose absorption. Consistent with these in vitro findings, rats injected with eCG (which shares structural and functional similarities with FSH) exhibited significantly increased adiponectin levels in both the ovaries and blood. Moreover, there was a notable elevation in mRNA and protein levels of AdipoRs and GLUTs following eCG administration. Transcriptomic analysis further revealed a positive correlation between the expression of the intraovarian adiponectin system and glucose transporter. The present study represents a novel investigation, demonstrating that FSH stimulates adiponectin secretion in ovarian granulosa cells through the PKA signaling pathway. This mechanism potentially influences glucose transport (GLUT1) and utilization within the ovaries.

GLUT1 overexpression enhances CAR T cell metabolic fitness and anti-tumor efficacy

The tumor microenvironment presents many obstacles to effective CAR T cell therapy, including glucose competition from tumor and myeloid cells. Using mouse models of acute lymphoblastic leukemia (ALL), renal cell carcinoma (RCC), and glioblastoma (GBM), we show that enforced expression of the glucose transporter GLUT1 enhances anti-tumor efficacy and promotes favorable CAR T cell phenotypes for two clinically relevant CAR designs, 19-28z and IL13Rα2-BBz. In the NALM6 ALL model, 19-28z-GLUT1 promotes Tscm formation and prolongs survival. RNA sequencing of these CAR T cells reveals that overexpression of GLUT1, but not GLUT3, enriches for genes involved in glycolysis, mitochondrial respiration, and memory precursor phenotypes. Extending these data, 19-28z-GLUT1 CAR T cells improve tumor control and response to rechallenge in an RCC patient derived xenograft model. Furthermore, IL13Rα2-BBz CAR T cells overexpressing GLUT1 prolong survival of mice bearing orthotopic GBMs and exhibit decreased exhaustion markers. This novel engineering approach can offer a competitive advantage to CAR T cells in harsh tumor environments where glucose is limiting.

Evaluation of the effects of dietary cinnamaldehyde on growth and nutrient use in Nile Tilapia (Oreochromis niloticus)

Cinnamaldehyde is an active organic compound and an aromatic aldehyde substance found in cinnamon oil. It is a new feed supplement for animals that can improve growth, nutrient digestion and absorption, lipid use, and immunity. The present study evaluated the effects of dietary trans-cinnamaldehyde 98 % (CIN) on nutrient utilization, antioxidant capacity, and growth performance in Nile tilapia (Oreochromis niloticus). Juveniles used was weighing at about 19.77 ± 0.10 g received dietary CIN at different doses (0, 0.25, 0.5, 0.75, and 1.0 g/kg feed). The fish were maintained in a glass aquarium of 95 × 45 × 35 cm3 in size at a stocking density of 20 fish per aquarium and fed three times a day to clear satiation. Dietary carbohydrate digestion and absorption were significantly improved in fish fed 0.75 g/kg CIN, as indicated by increased amylase activity and glucose tolerance test. The latter was subsequently confirmed by increases in relative ir, glut4, hx and gs expression that indicated the increase in glucose absorption led to an increase in glucose utilization as an energy source and the synthesis of glycogen as an energy reserve. Interestingly, dietary CIN supplementation also resulted in the downregulation of fas, which facilitates the conversion of glucose to fatty acids, and the upregulation of cpt1a and hsl, indicating increased fatty acid oxidation for energy. CIN at a range of 0.5–0.75 g/kg improved the antioxidant status in the liver, as illustrated by elevated glutathione peroxidase and superoxide dismutase activities (both P < 0.05). Final weight, feed consumption, the specific growth rate, feed efficiency, and protein retention increased were significantly in all CIN groups, with the highest values reached in the 0.5 g/kg CIN (all P < 0.05). Based on a polynomial orthogonal analysis of the fish-specific growth rate, the optimum dosage of CIN inclusion is 0.42 g/kg.

Amber (Succinite) Extract Enhances Glucose Uptake through the Up-Regulation of ATP and Down-Regulation of ROS in Mouse C2C12 Cells.

Traditionally, amber (Succinite) has been used to alleviate all types of pain, skin allergies, and headaches. However, no studies have been conducted on its antidiabetic and antioxidant effects. In this study, differentiated skeletal muscle C2C12 cells were used to demonstrate the protective effects of amber (AMB) against H2O2-induced cell death. In addition, the effects of AMB on glucose uptake and ATP production were investigated. Our results showed that AMB at 10, 25, and 50 μg/mL suppressed the elevation of ROS production induced by H2O2 in a dose-dependent manner. Moreover, AMB enhanced glucose utilization in C2C12 cells through the improvement of ATP production and an increase in PGC-1α gene expression resulting in an amelioration of mitochondrial activity. On the other hand, AMB significantly increased the gene expression of glucose transporters GLUT4 and GLUT1. Our finding suggests that AMB can be used as a natural supplement for diabetes treatment and for the promotion of skeletal muscle function.

Alkaloids in Uncaria rhynchophylla improves AD pathology by restraining CD4+ T cell-mediated neuroinflammation via inhibition of glycolysis in APP/PS1 mice

Ethnopharmacological relevanceUncaria rhynchophylla (Miq.) Miq.ex Havil. was a classical medicinal plant exhibiting the properties of extinguishing wind, arresting convulsions, clearing heat and pacifying the liver. Clinically, it could be utilized for the treatment of central nervous system-related diseases, such as Alzheimer's disease. U. rhynchophylla (UR) and its major ingredient alkaloid compounds (URA) have been proved to exert significant neuroprotective effects. However, the potential mechanism aren't fully understood. Aim of the studyThis study systematically examined the therapeutic effects of URA on AD pathology in APP-PS1 mice, and revealed the potential mechanism of action. Materials and methodsThe cognitive ability was evaluated by morris water maze test in APP-PS1 mice. The H&E staining was used to observe the tissue pathological changes. The ELISA kits were used to detect the level of inflammatory factors. The flow cytometry was used to analyze the percentage of CD4+ effector T cells (Teffs) in spleen. The immunofluorescent staining was performed to count the Teffs and microglia in brain. The protein expression was analyzed by western blot. In vitro, the lymphocyte proliferation induced by ConA was performed by CCK-8 kits. The IFN-γ, IL-17, and TNF-α production were detected by ELISA kits. The effects of URA on glycolysis and the involvement of PI3K/Akt/mTOR signaling pathway was analyzed by Lactic Acid assay kit and western blot in ConA-induced naive T cell. ResultsURA treatment improved AD pathology effectively as demonstrated by enhanced cognitive ability, decreased Aβ deposit and Tau phosphorylation, as well as reduced neuron apoptosis. Also, the neuroinflammation was significantly alleviated as evidenced by decreased IFN-γ, IL-17 and increased IL-10, TGF-β. Notably, URA treatment down-regulated the percentage of Teffs (Th1 and Th17) in spleen, and reduced the infiltration of Teffs and microglia in brain. Meanwhile, the Treg cell was up-regulated both in spleen and brain. In vitro, URA was capable of attenuating the spleen lymphocyte proliferation and release of inflammatory factors provoked by ConA. Interestingly, glycolysis was inhibited by URA treatment as evidenced by the decrease in Lactic Acid production and expression of HK2 and GLUT1 via regulating PI3K/Akt/mTOR signaling pathway in ConA-induced naive T cell. ConclusionThis study proved that URA could improve AD pathology which was possibly attributable to the restraints of CD4+ T cell mediated neuroinflammation via inhibiting glycolysis.

Abstract PS13-04: Frequent Intra-Tumoral Hypoxia in Pregnancy-Associated Breast Cancer

Abstract Rationale: Breast cancer is the most common malignancy in pregnant women, occurring in approximately 1:3000 pregnancies. Breast cancer diagnosed during pregnancy or after childbirth is also known as Pregnancy-Associated Breast Cancer (PABC). PABC is known for exhibiting several unfavorable prognostic tumor characteristics, such as an advanced tumor stage at diagnosis, high histologic grade and frequent hormone receptor negativity. Most probably, several interplaying mechanisms may promote the tumor progression and adverse clinical outcome of PABC. One of these mechanisms may be the presence of hypoxia, a relative state of low intra-tumoral oxygen levels which is a known marker of adverse outcome in breast cancer. However, the occurrence and prognostic consequences of the presence of intra-tumoral hypoxia in PABC have not been studied yet. Methods: We constructed a cohort with histopathological, clinical, and outcome data of patients diagnosed with breast cancer during pregnancy (PrBC) or within one year after childbirth (PPBC) in the Netherlands between 1988 and 2022. Next, tissue blocks of all patients were collected from the participating Dutch pathology laboratories. Using H&amp;E stained slides of the tumor tissue blocks, we selected suitable donor sites for a tissue micro array (TMA). Slides from these TMAs were stained for three important hypoxia-associated proteins: glucose transporter-1 (Glut-1), carbonic anhydrase IX (CAIX) and hypoxia-inducible factor-1α (HIF-1α). Expression was scored by an expert breast pathologist blinded by clinicopathologic data. Results: For a total of 195 PrBC and PPBC patients, we were able to assess the expression of Glut-1, CAIX and HIF-1α on tumor cells. Patients had a median age of 33 years at diagnosis, whilst a large majority had a Bloom &amp; Richardson grade III tumor (76%) with frequent hormone receptor negativity (50%). Expression of hypoxia-associated proteins was frequent, with 61% of the tumors expressing Glut-1, 30% expressing CAIX and 56% expressing HIF-1α. In total, 153 (78%) of the tumors expressed at least one of the hypoxia-associated proteins. We observed a significantly worse 5-year overall survival for patients with intra-tumoral hypoxia in comparison to patients without intra-tumoral hypoxia (70% vs. 90%, p=0.046). Conclusions: We show that the presence of intra-tumoral hypoxia in PABC is common, with 78% of tumors expressing at least one of the studied hypoxia-associated proteins. Importantly, patients with tumors overexpressing hypoxia-markers have a significantly worse survival. This shows that intra-tumoral hypoxia may be an important underlying carcinogenic mechanism in PABC, and might be a promising novel therapeutic target in this patient group. Citation Format: Carsten Bakhuis, Carmen Van Dooijeweert, Britt Suelmann, Pieter Westenend, Sabine Linn, Elsken Van der Wall, Paul Van Diest. Frequent Intra-Tumoral Hypoxia in Pregnancy-Associated Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS13-04.

Regulation of iodine-glucose flip-flop in SW1736 anaplastic thyroid cancer cell line.

The alternative manner of iodide and glucose uptake found in different types of thyroid cancer, referred to flip-flop. ATC cells indicate low iodide uptake and high glucose uptake, which lack the morphology and genetic characteristics of well-differentiated tumors and become increasingly invasive. Importance placed on the discovery of innovative multi-targeted medicines to suppress the dysregulated signaling in cancer. In this research, we aimed to clarify molecular mechanism of Rutin as a phytomedicine on anaplastic thyroid cancer cell line based on iodide and glucose uptake. The MTT test was employed to test cell viability. Iodide uptake assay was performed using a spectrophotometric assay to determine iodide uptake in SW1736 cells based on Sandell-Kolthoff reaction. For glucose uptake detection, ''GOD-PAP'' enzymatic colorimetric assay was applied to measure the direct glucose levels inside of the cells. Determination of NIS, GLUT1 and 3 mRNA expression in SW1736 cells was performed by qRT-PCR. Determination of NIS, GLUT1 and 3 protein levels in SW1736 cells was performed by western blotting. According to our results, Rutin inhibited the viability of SW1736 cells in a time- and dose-dependent manner. Quantitative Real-time RT-PCR analysis exposed that NIS mRNA levels were increased in Rutin treated group compared to the control group. Accordingly, western blot showed high expression of NIS protein and low expression of GLUT 1 and 3 in Rutin treated SW1736 cell line. Rutin increased iodide uptake and decreased glucose uptake in thyroid cancer cell line SW1736 compared to control group. Multiple mechanisms point to Rutin's role as a major stimulator of iodide uptake and inhibitor of glucose uptake, including effects at the mRNA and protein levels for both NIS and GLUTs, respectively. Here in, we described the flip-flop phenomenon as a possible therapeutic target for ATC. Moreover, Rutin is first documented here as a NIS expression inducer capable of restoring cell differentiation in SW1736 cell line. It also be concluded that GLUTs as metabolic targets can be blocked specifically by Rutin for thyroid cancer prevention and treatment.

Glucose-driven histone lactylation promotes the immunosuppressive activity of monocyte-derived macrophages in glioblastoma

Immunosuppressive macrophages restrict anti-cancer immunity in glioblastoma (GBM). Here, we studied the contribution of microglia (MGs) and monocyte-derived macrophages (MDMs) to immunosuppression and mechanisms underlying their regulatory function. MDMs outnumbered MGs at late tumor stages and suppressed Tcell activity. Molecular and functional analysis identified a population of glycolytic MDM expressing GLUT1 with potent immunosuppressive activity. GBM-derived factors promoted high glycolysis, lactate, and interleukin-10 (IL-10) production in MDMs. Inhibition of glycolysis or lactate production in MDMs impaired IL-10 expression and Tcell suppression. Mechanistically, intracellular lactate-driven histone lactylation promoted IL-10 expression, which was required to suppress Tcell activity. GLUT1 expression on MDMs was induced downstream of tumor-derived factors that activated the PERK-ATF4 axis. PERK deletion in MDM abrogated histone lactylation, led to the accumulation of intratumoral Tcells and tumor growth delay, and, in combination with immunotherapy, blocked GBM progression. Thus, PERK-driven glucose metabolism promotes MDM immunosuppressive activity via histone lactylation.

Long-term intermittent fasting induces sex-dependent changes in small intestine from SAMP8 aged mice

Background: Intermittent fasting (IF) is a popular and effective method to decrease body weight. Yet, the effects of IF on aged intestine is unknown. SAMP8 (Senescence Accelerated Mouse-Prone 8) mice are used as a model for studying aging. This study aimed to examine the potential for IF to ameliorate age-associated disturbances in murine jejunum. Methods: Two-month-old male and female SAMP8 mice were randomly assigned to either an IF protocol or an ad-libitum diet (AL) for the 8-month study (n=7-10 group). Fasted mice followed a 24-hour alternate day fasting protocol. At the end of the study mice were euthanized and jejunum stored at −80°C until use for western blot or other assay, and a segment was fixed for histology. Results: IF resulted in significantly less weight gain in both males (22% less, n=7-10, p&lt;0.05) and females (33% less, n=7-8, p&lt;0.05) and response to glucose load (glucose tolerance testing) was comparable in both sexes: area under curve for AL &gt; IF. Interestingly, IF significantly reduced fasting serum glucose levels in males (30% less, n=6, p&lt;0.05), but IF had no effect on fasting serum glucose in females. In jejunum, we assessed: protein expression, health, and morphology. In females, IF led to a 57% decrease in GLUT2 expression (n=5-6, p&lt;0.05) versus AL. GLUT2 moves glucose/galactose and fructose out of the enterocyte into the blood, suggesting restructuring of monosaccharide transport due to IF. IF had no effect on jejunum GLUT5 or SGLT1 expression. Cleaved Caspase-3 expression was decreased by IF in both sexes versus AL. This reduction was greater in females, suggesting a sex-dependent protective role of IF against apoptosis. Moreover, IF induced a significant increase 1.4-fold (n=5=6, p&lt;0.05) in jejunum superoxide dismutase (SOD) activity in both sexes. Jejunum morphology was significantly changed in females only: IF induced both a decrease in villi length (by 21%, n=4/group, p&lt;0.05) and a decrease in wall thickness (by 7%, n=4/group, p&lt;0.05). Conclusions: In both sexes, IF decreased body weight, yet in females resting glucose levels were unchanged by IF. In females, IF reduced monosaccharide absorption out of intestines, yet improved overall intestinal health, increasing antioxidant levels with SOD. These findings collectively highlight the complex effects of IF on cellular processes and demonstrate significant sex-dependent aged intestinal responses. Unraveling the underlying molecular mechanisms driving these sex-dependent IF-induced effects is currently under evaluation. Midwestern-Arizona Alzheimer’s Consortium Grant, Midwestern University Intramural Grant. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

In Utero Overnutrition Influences Placental Nutrient Transport and Fetal Overgrowth

Obesity is defined as a body mass index (BMI) ≥30 kg/m2. Forty-three percent of women of childbearing age are obese, with a greater prevalence noted in Black women. Obesity increases the risk of diabetes (Type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM)). Obesity and diabetes are chronic states of overnutrition and metabolic dysregulation, each associated with an increased risk of macrosomia (large weight for gestational age in offspring). Macrosomia not only increases pregnancy complications but also increases the risk of metabolic disorders throughout the lifespan of the offspring. Fetal growth in utero is mediated by the nutritional environment and nutritional transport across the placenta. Maternal-fetal nutrient transport is primarily mediated by placental transporters for glucose, amino acids, free fatty acids, and cholesterol in the syncytiotrophoblast of the placenta. Yet, the mechanistic pathway driving fetal overgrowth in environments of overnutrition are not well defined. Therefore, we will test the hypothesis that diabetes (T2DM or GDM) exacerbates placental nutrient transport and fetal overgrowth in Black pregnant women with obesity. To evaluate the combined influence of obesity and diabetes (T2DM or GDM) on fetal growth, we evaluated n=100 electronic medical records of Black obese women with and without diabetes (T2DM or GDM) from 2012-2022 at the University of Mississippi Medical Center (UMMC). These women were singleton pregnancies with no additional underlying conditions. Gestational age of offspring and maternal age were similar among all groups. This study was approved by the Institutional Review Board at UMMC (IRB-UMMC-2021-0455). We found that Black obese women with diabetes (n=43) had higher BMIs compared to Black women with obesity alone (n=57) (43.50 ± 4.76 kg/m2 vs. 39.19 ± 3.48 kg/m2) (p&lt;0.05), indicating that obesity increases risk of diabetes in Black pregnant women. Additionally, offspring from Black obese women with diabetes had elevated birthweight compared to offspring from women with obesity alone (3345 ± 614.6 g vs. 3099 ± 465.4 g; p&lt;0.05). Male offspring from Black obese women with diabetes had elevated birthweight (3460 ± 695.8 g) compared to female offspring from Black obese women without diabetes (3068 ± 439.8 g) (p&lt;0.05), suggesting the maternal nutritional environment influences males more than females. Yet, the type of diabetes, T2DM or GDM, did not influence birthweight in offspring from Black obese women (T2DM: 3412 ± 743.5 g vs GDM: 3271 ± 439.7 g). To evaluate the influence of obesity plus diabetes on placental nutrient transport, we measured placental protein expression of glucose transporter-1 (Glut-1), a primary glucose transporter in the placenta, in a separate subset of placental tissue from Black obese women with and without diabetes (IRB-UMMC-2019-0058). Protein expression of Glut-1 was increased in placental tissue from Black women with obesity and diabetes (n=4) compared to Black women with obesity alone (n=4) (20.38 ± 5.87 A.U. vs. 9.41 ± 1.46 A.U.; p&lt;0.05). However, BMI was elevated in the group of women with obesity and diabetes compared to obesity alone (49.565 ± 1.39 kg/m2 vs. 43.44 ± 2.44 kg/m2; p&lt;0.05), again indicating that obesity increases risks of diabetes in Black pregnant women. This study indicates that combined obesity with diabetes during pregnancy is associated with increased birthweight and placental protein expression of Glut-1. Additional studies are warranted to decipher the separate influences of elevated BMI and diabetes on fetal growth, along with the associated placental mechanisms that influence nutrient transport and fetal growth in pregnancies complicated by obesity and diabetes. UMMC Department of OBGYN. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Endothelial PPARD regulates nutrient transport and exercise endurance in mice

Vascular endothelial cell function is important for regulating vascular perfusion, which is increased in the skeletal muscle during exercise. Our previous research identified endothelial selective PPARD, a transcription factor, which is critical for endothelial cell function and homeostasis. Loss of PPARD in endothelium enhances vascular inflammation and disrupts endothelial integrity. In the present study, we aims to investigate whether endothelial PPARD is involved in nutrient transport in the muscle endothelial cells and whether it is involved in exercise endurance and training effcacy. The Cdh5-Cre driven deletion of the floxed Ppard allele was used for making the endothelium selective Ppard knockout (PpardEC-KO) mice and wild type littermates (PpardEC-WT). Human endothelial cells were used to examine glucose and fatty acid uptake and its transport to myocytes. Treadmill exercise with incremental speed and inclination was used. Both PpardEC-WT and PpardEC-KO mice were viable and did not show abnormalities at baseline. Both PpardEC-WT and PpardEC-KO mice were put on treadmill to test their running endurance. Deletion of Ppard in endothelium resulted in early exhaustion, shortened distance, and less speed. Running exercise for 4 weeks partially improved endurance in the PpardEC-KO mice. PpardEC-KO mice had less oxidative muscle fibers both at baseline and after training. Higher blood lactate level and less glucose preservation were found in PpardEC-KO mice after running the same distance as PpardEC-WT mice. In human endothelial cells, PPARD knockdown resulted in less glucose and fatty acid uptake. Glucose transport to myocyte from endothelial cells was also attenuated with PPARD knockdown. PPARD may act through SGK1 responsible for GLUT1 expression and glucose uptake. Our study showed an important role of endothelial cell in regulating nutrient transport into skeletal muscle during physical exercise. Impaired endothelial transport of glucose and fatty acid reduces exercise endurance. This study is funded by the General Research Funds 14107822 and 14105321 from the Hong Kong University Grant Council. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Expression Profiling of Genes Associated with the Pathogenesis of Recurrent Laryngeal Papillomatosis

Recurrent Laryngeal Papillomatosis (RLP) affects the aero-digestive intersection with a predilection for the glottis. It is predominantly a juvenile-onset disease. The main infectious agents are type 6 and 11 low-risk human papillomaviruses. Understanding the genetic changes associated with the pathogenesis of RLP might prove helpful to mark the severity and aggression of the disease and lead to better clinical management. Clinically diagnosed RLP children below the age of 12 years along with a control sample of healthy tissue from age and gender-matched children undergoing tonsillectomy and thyroidectomy were collected. All the samples were processed for total RNA extraction followed by first strand cDNA synthesis. Real-time PCR was done to determine the relative gene expression of EGFR, ER-α, CXCL12, CXCR4, GLUT-1, IGF-1, HIF-1α, VEGF, ERK1/2, PI3K and AKT genes along with GAPDH as gene of reference. An increase in the transcriptional level expression of the genes CXCL12/CXCR4, GLUT-1, EGFR, ER-α, and IGF-I was observed in the cases in comparison to the controls. The expression of HIF-1α, VEGF, PI3K, and AKT genes was not noticeably elevated. The gene expression analysis may open the avenues for possible strategies that can be employed to treat RLP more effectively.

Potential role of resveratrol in prevention and therapy of diabetic complications: a critical review.

Diabetes mellitus (DM) is a category of metabolic conditions affecting about 5% of people worldwide. High mortality associated with DM is mostly due to its severe clinical complications, including diabetic nephropathy, retinopathy, neuropathy, and cardiomyopathy. Resveratrol (RSV) is a natural, biologically active polyphenol known to have various health-promoting effects in animal models and humans. In this review, we have reviewed the preventive and therapeutic role of RSV on diabetes complications with emphasis on its molecular mechanisms of action. To prepare this review, all the basic and clinical available literatures regarding this topic were gathered through electronic databases, including PubMed, Web of Science, Scopus, and Google Scholar. Therefore, we summarized previous studies that have evaluated the effects of RSV on diabetic complications and their mechanisms. Only English language studies published up to January 2023 were included in this review. RSV improves glucose homeostasis, decreases insulin resistance, induces autophagy, regulates lipid metabolism, protects pancreatic β-cells, ameliorates metabolic disorders, and increases the GLUT4 expression. These effects induced by RSV are strongly associated with ability of this polyphenol agent to elevation expression/activity of AMP-activated protein kinase and Sirtuin 1 in various organs of diabetic subjects, which leads to prevention and therapy of diabetic complications. In addition, antioxidant and anti-inflammatory properties of RSV were reported to be involved in its action in diabetic complications, such as retinopathy and nephropathy. RSV is a promising compound for improving diabetic complications. However, the exact antidiabetic mechanisms of RSV need to be further investigated.

GPR30 selective agonist G-1 induced insulin resistance in ovariectomized mice on high fat diet and its mechanism

BackgroundPrevious in vivo and in vitro studies have demonstrated that estrogen receptor agonist G-1 regulates glucose and lipid metabolism. This study focused on the effects of G-1 on cardiometabolic syndrome and anti-obesity under a high fat diet (HFD). MethodsBilateral ovariectomized female mice were fed an HFD for 6 weeks, and treated them with G-1. A cardiomyocyte insulin resistance model was used to simulate the in vivo environment. The main outcome measures were blood glucose, body weight, and serum insulin levels to assess insulin resistance, while cardiac function and degree of fibrosis were assessed by cardiac ultrasound and pathological observations. We also examined the expression of p-AMPK, p-AKT, and GLUT4 in mice hearts and in vitro models to explore the mechanism by which G-1 regulates insulin signaling. ResultsG-1 reduced body weight in mice on an HFD, but simultaneously increased blood glucose and promoted insulin resistance, resulting in myocardial damage. This damage included disordered cardiomyocytes, massive accumulation of glycogen, extensive fibrosis of the heart, and thickening of the front and rear walls of the left ventricle. At the molecular level, G-1 enhances gluconeogenesis and promotes glucose production by increasing the activity of pyruvate carboxylase (PC) while inhibiting GLUT4 translocation via the AMPK/TBC1D1 pathway, thereby limiting glucose uptake. ConclusionDespite G-1's the potential efficacy in weight reduction, the concomitant induction of insulin resistance and cardiac impairment in conjunction with an HFD raises significant concerns. Therefore, comprehensive studies of its safety profile and effects under specific conditions are essential prior to clinical use.

Effects of two types of exercises on MCT1 and GLUT4 expression in visceral white adipose tissue in type I diabetic rats

Effects of two types of exercises on MCT1 and GLUT4 expression in visceral white adipose tissue in type I diabetic rats

Melatonin as a promising agent alleviating endocrine deregulation and concurrent cardiovascular dysfunction: a review and future prospect

Endocrine modulation of various growth and survival mechanisms is at the helm of cellular homeostasis and impaired endocrine balance may potentially galvanize cardiovascular health to go haywire. Melatonin, an effective antioxidant and multipotent hormone has preponderant influence on the activities of several endocrine factors including growth hormones, thyroid hormones, gastro-intestinal hormones, and those controlling reproductive and metabolic functions. Many of these hormones tightly regulate cardiovascular functions while the mammalian heart has its own endocrine machinery. Endocrine disruptions severely affect cardiovascular integrity and hormonal therapies may instigate adverse cardiac events. Therefore, this review focuses on the cardioprotective potential of melatonin concerning endocrine instability-mediated cardiovascular dysfunction. Melatonin has been reported to effectively counteract sympathetic overstimulation and also reduce the cardiotoxic attributes of catecholamines and their derivatives. Melatonin suppresses the pernicious cardiovascular manifestation of thyrotoxicosis and autoimmune thyroiditis, which is possibly attributed to its antioxidant property and regulation of iodothyronine-deiodinase activity. Interestingly, being a circadian synchronizer melatonin potentially preserves the diurnal pattern of insulin secretion and thereby improves glucose tolerance and cardiac GLUT-4 expression. Besides, melatonin modulates insulin signaling pathway by enhancing the activation of insulin receptor-associated tyrosine kinase, thus protecting the heart against diabetogenic outcomes. Further, melatonin has demonstrated its beneficial action against non-dipper hypertension by regulating the RAAS function. However, there is a plethora of unresolved research question that necessitates additional investigation into the potential therapeutic effect of melatonin in endocrine dysfunctions that emanates during various physiological and pathological states and may have potentially harmful cardiovascular implications.

Diverse effects of a Cyperus rotundus extract on glucose uptake in myotubes and adipocytes and its suppression on adipocyte maturation

Cyperus rotundus rhizomes have been used in longevity remedies in Thailand for nourishing good health, which led us to investigate the effect on energy homeostasis, especially glucose utilization in myotubes and adipocytes, and on inhibition of lipogenesis in adipocytes. The results showed that an ethyl acetate extract of C. rotundus rhizomes (ECR) containing 1.61%w/w piceatannol, with a half-maximal concentration of 17.76 ± 0.03 μg/mL in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, caused upregulation and cell-membrane translocation of glucose transporters GLUT4 and 1 in L6 myotubes but downregulation and cytoplasmic localization of GLUT4 expression in 3T3-L1 adipocytes and was related to the p-Akt/Akt ratio in both cells, especially at 100 μg/mL. Moreover, ECR (25–100 μg/mL) significantly inhibited lipid accumulation via Adenosine Monophosphate-Activated Protein Kinase (AMPK), Acetyl CoA Carboxylase (ACC), and Glycogen Synthase Kinase (GSK) pathways. Its immunoblot showed increased expression of p-AMPKα/AMPKα and p-ACC/ACC but decreased expression of p-Akt/Akt and p-GSK3β/GSK3β in 3T3-L1 adipocytes. Moreover, the decreased expression of the adipogenic effectors, perilipin1 and lipoprotein lipase, in ECR-incubated adipocytes (50 and 100 μg/mL) indicated reduced de novo lipogenesis. Our study elucidated mechanisms of C. rotundus that help attenuate glucose tolerance in skeletal muscle and inhibit lipid droplet accumulation in adipose tissue.

GLUT1-mediated microglial proinflammatory activation contributes to the development of stress-induced spatial learning and memory dysfunction in mice.

Stress is a recognized risk factor for cognitive decline, which triggers neuroinflammation involving microglial activation. However, the specific mechanism for microglial activation under stress and affects learning and memory remains unclear. The chronic stress mouse model was utilized to explore the relationship between microglial activation and spatial memory impairment. The effect of hippocampal hyperglycemia on microglial activation was evaluated through hippocampal glucose-infusion and the incubation of BV2 cells with high glucose. The gain-and loss-of-function experiments were conducted to investigate the role of GLUT1 in microglial proinflammatory activation. An adeno-associated virus (AAV) was employed to specifically knockdown of GLUT1 in hippocampal microglia to assess its impact on stressed-mice. Herein, we found that chronic stress induced remarkable hippocampal microglial proinflammatory activation and neuroinflammation, which were involved in the development of stress-related spatial learning and memory impairment. Mechanistically, elevated hippocampal glucose level post-stress was revealed to be a key regulator of proinflammatory microglial activation via specifically increasing the expression of microglial GLUT1. GLUT1 overexpression promoted microglial proinflammatory phenotype while inhibiting GLUT1 function mitigated this effect under high glucose. Furthermore, specific downregulation of hippocampal microglial GLUT1 in stressed-mice relieved microglial proinflammatory activation, neuroinflammation, and spatial learning and memory injury. Finally, the NF-κB signaling pathway was demonstrated to be involved in the regulatory effect of GLUT1 on microglia. We demonstrate that elevated glucose and GLUT1 expression induce microglia proinflammatory activation, contributing to stress-associated spatial memory dysfunction. These findings highlight significant interplay between metabolism and inflammation, presenting a possible therapeutic target for stress-related cognitive disorders.

Phenotypes of streptozotocin-induced gestational diabetes mellitus in mice.

Gestational diabetes mellitus (GDM) in human patients disrupts glucose metabolism post-pregnancy, affecting fetal development. Although obesity and genetic factors increase GDM risk, a lack of suitable models impedes a comprehensive understanding of its pathology. To address this, we administered streptozotocin (STZ, 75 mg/kg) to C57BL/6N mice for two days before pregnancy, establishing a convenient GDM model. Pregnant mice exposed to STZ (STZ-pregnant) were compared with STZ-injected virgin mice (STZ-virgin), citrate buffer-injected virgin mice (CB-virgin), and pregnant mice injected with citrate buffer (CB-pregnant). STZ-pregnant non-obese mice exhibited elevated blood glucose levels on gestational day 15.5 and impaired glucose tolerance. They also showed fewer normal fetuses compared to CB-pregnant mice. Additionally, STZ-pregnant mice had the highest plasma C-peptide levels, with decreased pancreatic islets or increased alpha cells compared to CB-pregnant mice. Kidneys isolated from STZ-pregnant mice did not display histological alterations or changes in gene expression for the principal glucose transporters (GLUT2 and SGLT2) and renal injury-associated markers. Notably, STZ-pregnant mice displayed decreased gene expression of insulin-receiving molecules (ISNR and IGFR1), indicating heightened insulin resistance. Liver histology in STZ-pregnant mice remained unchanged except for a pregnancy-related increase in lipid droplets within hepatocytes. Furthermore, the duodenum of STZ-pregnant mice exhibited increased gene expression of ligand-degradable IGFR2 and decreased expression of GLUT5 and GLUT12 (fructose and glucose transporters, respectively) compared to STZ-virgin mice. Thus, STZ-pregnant mice displayed GDM-like symptoms, including fetal abnormalities, while organs adapted to impaired glucose metabolism by altering glucose transport and insulin reception without histopathological changes. STZ-pregnant mice offer a novel model for studying mild onset non-obese GDM and species-specific differences in GDM features between humans and animals.