GLUT4 Expression Research Articles

The improvement of modified Si-Miao granule on hepatic insulin resistance and glycogen synthesis in type 2 diabetes mellitus involves the inhibition of TNF-α/JNK1/IRS-2 pathway: network pharmacology, molecular docking, and experimental validation

BackgroundModified Si-Miao granule (mSMG), a traditional Chinese medicine, is beneficial for T2DM and insulin resistance (IR), but the underlying mechanism remains unknown.MethodsUsing network pharmacology, we screened the compounds of mSMG and identified its targets and pathway on hepatic IR in T2DM. Using molecular docking, we identified the affinity between the compounds and hub target TNF-α. Then these were verified in KK-Ay mice and HepG2 cells.Results50 compounds and 170 targets of mSMG against IR in T2DM were screened, and 9 hub targets such as TNF and MAPK8 were identified. 170 targets were mainly enriched in insulin resistance and TNF pathway, so we speculated that mSMG might act on TNF-α, JNK1 and then regulate insulin signaling to mitigate IR. Experimental validation proved that mSMG ameliorated hyperglycemia, IR, and TNF-α, enhanced glucose consumption and glycogen synthesis, relieved the phosphorylation of JNK1 and IRS-2 (Ser388), and elevated the phosphorylation of Akt (Ser473) and GSK-3β (Ser9) and GLUT2 expression in KK-Ay mice. Molecular docking further showed berberine from mSMG had excellent binding capacity with TNF-α. Then, in vitro validation experiments, we found that 20% mSMG-MS or 50 μM berberine had little effect in IR-HepG2 cell viability, but significantly increased glucose consumption and glycogen synthesis and regulated TNF-α/JNK1/IRS-2 pathway.ConclusionNetwork pharmacology and molecular docking help us predict potential mechanism of mSMG and further guide experimental validation. mSMG and its representative compound berberine improve hepatic IR and glycogen synthesis, and its mechanism may be related to the inhibition of TNF-α/JNK1/IRS-2 pathway.

Comparison of Gene Expression for Preimplantation Genes in Bovine Embryos Fertilized in vitro

Background: In vitro fertilization (IVF) the technique is useful for understanding early mammalian development and maximizing and speeding up genetic improvement in livestock. Genes that function as genetic markers and are involved in the pre-implantation development of embryos may be used to evaluate the quality of an embryo and the expression of these genes is correlated with the timing of embryonic genomic activation. Methods: Maturing the oocytes of bovine, then fertilizing these matured oocytes and finally culturing the fertilized oocytes to develop into embryos. Determined the gene expression of different certain genes HSP70, OCT4, GLUT1, BAX and DNMT1 in these different cell stages of embryos that were produced. Result: The mRNA expression of these genes was estimated after collecting the embryos listed above that were produced by the in vitro technique. The results showed statistically significant differences in the relative abundance between some of the genes mentioned above in each embryo stage. The timing of the zygotic genome activation process (ZGA) can result in differences in gene expression levels between the early embryonic genes in each developmental stage of in vitro-produced bovine embryos.

STC2 knockdown inhibits cell proliferation and glycolysis in hepatocellular carcinoma through promoting autophagy by PI3K/Akt/mTOR pathway

BackgroundThe pathogenesis exploration and timely intervention of hepatocellular carcinoma (HCC) are crucial due to its global impact on human health. As a general tumor biomarker, stanniocalcin 2 (STC2), its role in HCC remains unclear. We aimed to analyze the effect and mechanism of STC2 on HCC. MethodsSTC2 expressions in HCC tissues and cell lines were measured. si-STC2 and oe-STC2 transfections were utilized to analyze how STC2 affected cell functions. Functional enrichment analysis of STC2 was performed by Gene Set Enrichment Analysis (GSEA). The regulatory mechanism of STC2 on HCC was investigated using 2-DG, 3-MA, IGF-1, Rap, and LY294002. The impact of STC2 on HCC progression in vivo was evaluated by the tumor formation experiment. ResultsHigher levels of STC2 expression were observed in HCC tissues and cell lines. Besides, STC2 knockdown reduced proliferation, migration, and invasion, while inducing cell apoptosis. Further analysis indicated a positive correlation between STC2 and glycolysis. STC2 knockdown inhibited glycolysis progression and down-regulated the expressions of PKM2, GLUT1, and HK2 in HCC cells. However, treatment with glycolysis inhibitor (2-DG) prevented oe-STC2 from promoting the growth of HCC cells. Additionally, STC2 knockdown up-regulated the levels of LC3II/LC3I and Beclin1 and reduced the phosphorylation of PI3K, AKT, and mTOR. Treatment with 3-MA, IGF-1, Rap, and LY294002 altered the function of STC2 on proliferation and glycolysis in HCC cells. Tumor formation experiment results revealed that STC2 knockdown inhibited HCC progression. ConclusionsSTC2 knockdown inhibited cell proliferation and glycolysis in HCC through the PI3K/Akt/mTOR pathway-mediated autophagy induction.

KLF3 impacts insulin sensitivity and glucose uptake in skeletal muscle.

Skeletal muscle is one of the predominant sites involved in glucose disposal, accounting for approximately 80% of postprandial glucose uptake, and plays a critical role in maintaining glycemic homeostasis. Dysregulation of energy metabolism in skeletal muscle is involved in developing insulin resistance and type 2 diabetes (T2D). Transcriptomic responses of skeletal muscle to exercise found that the expression of Klf3 was increased in T2D Goto-Kakizaki (GK) rats and decreased after exercise with improved hyperglycemia and insulin resistance, implying that Klf3 might be associated with insulin sensitivity and glucose metabolism. We also found that knockdown of Klf3 promoted basal and insulin-stimulated glucose uptake in L6 myotubes, while overexpression of Klf3 resulted in the opposite. Through pairwise comparisons of L6 myotubes transcriptome, we identified 2256 and 1988 differentially expressed genes in Klf3 knockdown and overexpression groups, respectively. In insulin signaling, the expression of Slc2a4, Akt2, Insr and Sorbs1 was significantly increased by Klf3 knockdown and decreased with klf3 overexpression; Ptprf and Fasn were markedly downregulated in klf3 reduced group and upregulated in klf3 overexpressed group. Moreover, downregulation of Klf3 promoted the expression of GLUT4 and AKT proteins, as well as the translocation of GLUT4 to the cell membrane in the basal situation, and enhanced insulin sensitivity, characterized by increased insulin-stimulated GLUT4 translocation and AKT, TBC1D1 and TBC1D4 phosphorylation, while overexpression of Klf3 showed contrary results. These results suggest that Klf3 affects glucose uptake and insulin sensitivity via insulin signal transduction and intracellular metabolism, offering a novel potential treatment strategy for T2D.

Oligodendroglial fatty acid metabolism as a central nervous system energy reserve

Brain function requires a constant supply of glucose. However, the brain has no known energy stores, except for glycogen granules in astrocytes. In the present study, we report that continuous oligodendroglial lipid metabolism provides an energy reserve in white matter tracts. In the isolated optic nerve from young adult mice of both sexes, oligodendrocytes survive glucose deprivation better than astrocytes. Under low glucose, both axonal ATP levels and action potentials become dependent on fatty acid β-oxidation. Importantly, ongoing oligodendroglial lipid degradation feeds rapidly into white matter energy metabolism. Although not supporting high-frequency spiking, fatty acid β-oxidation in mitochondria and oligodendroglial peroxisomes protects axons from conduction blocks when glucose is limiting. Disruption of the glucose transporter GLUT1 expression in oligodendrocytes of adult mice perturbs myelin homeostasis in vivo and causes gradual demyelination without behavioral signs. This further suggests that the imbalance of myelin synthesis and degradation can underlie myelin thinning in aging and disease.

Exercise performance and health: Role of GLUT4

The glucose transporter GLUT4 is integral for optimal skeletal muscle performance during exercise, as well as for metabolic health. Physiological regulation of GLUT4 translocation during exercise and increased GLUT4 expression following exercise involves multiple, redundant signalling pathways. These include effects of reactive oxygen species (ROS). ROS contribute to GLUT4 translocation that increases skeletal muscle glucose uptake during exercise and stimulate signalling pathways that increase GLUT4 expression. Conversely, ROS can also inhibit GLUT4 translocation and expression in metabolic disease states. The opposing roles of ROS in GLUT4 regulation are ultimately linked to the metabolic state of skeletal muscle and the intricate mechanisms involved give insights into pathways critical for exercise performance and implicated in metabolic health and disease.

Reduction of hyperglycemia in STZ-induced diabetic mice by prophylactic treatment with heat-killed Mycobacterium aurum: possible effects on glucose utilization, mitochondrial uncoupling, and oxidative stress in liver and skeletal muscle.

In addition to conventional treatment and modifications in physical activity and diet, alternative strategies have been investigated to manage, prevent, or delay diabetes in humans. In this regard, one strategy has relied on the immunomodulatory properties of mycobacteria, whereby Bacillus Calmette-Guerin, an attenuated live strain of Mycobacterium bovis, has been shown to improve glycemic control in patients with diabetes and to alleviate hyperglycemia in selected murine models of diabetes. A novel heat-killed (HK) whole-cell preparation of Mycobacterium aurum (M. aurum) is currently under development as a potential food supplement; nevertheless, its potential bioactivity remains largely unknown. Thus, the present study investigated the potential prophylactic anti-diabetic effects of HK M. aurum in streptozotocin (STZ)-induced diabetic mice. Mice were divided into three groups: the STZ-induced diabetic group was injected with a single intraperitoneal high dose of STZ, the HK M. aurum-treated diabetic group was prophylactically treated with three doses of HK M. aurum 6 weeks before STZ injection, and the control non-diabetic group was given three intradermal injections of borate-buffered saline and an intraperitoneal injection of citrate buffer. Liver lactate dehydrogenase (LDH), uncoupling protein 2 (UCP2), and glucose transporter 2 (GLUT2) and skeletal muscle LDH, UCP3, and GLUT4 protein expression levels in different mouse groups were determined by Western blot. Our results indicated that HK M. aurum did not cause any significant changes in glycemic levels of normal non-diabetic mice. Prophylactic administration of three doses of HK M. aurum to diabetic mice resulted in a significant reduction in their blood glucose levels when compared to those in control diabetic mice. Prophylactic treatment of diabetic mice with HK M. aurum significantly restored their disturbed protein expression levels of liver UCP2 and LDH as well as of skeletal muscle UCP3. On the other hand, prophylactic treatment of diabetic mice with HK M. aurum had no significant effect on their liver GLUT2 and skeletal muscle GLUT4 and LDH protein expression levels. Our findings provide the first evidence that HK M. aurum possesses a hyperglycemia-lowering capacity and might support its future use as a food supplement for the amelioration of diabetes.

Dietary Supplementation with 25-Hydroxyvitamin D3 on Reproductive Performance and Placental Oxidative Stress in Primiparous Sows during Mid-to-Late Gestation.

The placenta plays a crucial role in nutrient transport and waste exchange between the dam and fetus, sustaining fetal growth. While the positive effects of 25-hydroxyvitamin D3 (25-OH-D3) on animal performance have been reported, its impact on placental function remains largely unknown. Therefore, this study aimed to investigate the effects of supplementing 25-OH-D3 in the diet of primiparous sows on reproductive performance, antioxidant capacity, placental oxidative stress, nutrient transport, and inflammatory response during mid-to-late gestation. A total of 45 healthy Landrace × Yorkshire primiparous sows on day 60 of gestation were selected and randomly allocated to three treatment groups based on body weight and backfat thickness: the control group (corn-soybean meal basal diet), the VD3 group (basal diet + 2000 IU VD3), and the 25-OH-D3 group (basal diet + 50 μg/kg 25-OH-D3). The results demonstrated that supplementation with 25-OH-D3 in the diet enhanced sows' average litter weight and birth weight during mid-to-late gestation. Additionally, plasma malondialdehyde (MDA) concentrations in sows significantly decreased in the VD3 and 25-OH-D3 groups (p < 0.05). Furthermore, lower gene expressions of placental HO-1, GPX2, IL-8, and IL-6 were found in the VD3 or 25-OH-D3 groups (p < 0.05 or p < 0.10), while higher gene expressions of GLUT1 and SNAT2 in the placenta of sows were observed in the VD3 and 25-OH-D3 groups, respectively (p < 0.05). These findings indicate that the supplementation of VD3 and 25-OH-D3 in the diet of sows can improve their plasma oxidative stress status, enhance placental antioxidant capacity and nutrient transport, and reduce placental inflammatory responses, with more pronounced improvements in sow performance observed in sows fed diets supplemented with 25-OH-D3.

Salmon Milt Extract Suppresses Glucose Uptake by Downregulating SGLT1 and GLUT2 Expression in Caco-2 Cells.

Salmon milt extract (SME) is rich in nucleotides, especially deoxyribonucleoside monophosphates (dNMPs), which has the potential to exert anti-obesity effects. Sodium-dependent glucose transporter 1 (SGLT1) and glucose transporter 2 (GLUT2) are responsible for absorbing sugar from the small intestine. The purpose of this study was to examine the effects of SME on the functions of SGLT1 and GLUT2 and elucidate the mechanisms underlying the inhibition of glucose absorption by SME. We investigated the effect of SME on the expression and function of intestinal glucose transporters, using differentiated Caco-2 cells. SME treatment decreased the expression SGLT1 and GLUT2 mRNA and protein in Caco-2 cells. [14C]-Labelled methyl-α-D-glucopyranoside and [3H]-labelled 2-deoxy-D-glucose (DG) uptake into Caco-2 cells was significantly reduced by SME treatment. Similarly, the dNMP mixture containing the four mononucleotides 2'-deoxyadenosine 5'-monophosphate (dAMP), 2'-deoxyguanosine 5'-monophosphate (dGMP), 2'-deoxycytidine 5'-monophosphate (dCMP), and 2'-deoxythymidine 5'-monophosphate (dTMP) decreased SGLT1 and GLUT2 expression. dNMP mixture-induced reduction in the mRNA expression of these transporters was suppressed when exposed to the mixture without dTMP. Furthermore, dNMP mixture-induced alterations in the expression of hepatocyte nuclear factor (HNF)-1α and HNF1β, which have been characterized as modulators of both transporters also showed a similar trend. dTMP treatment alone decreased GLUT2 expression, resulting in reduced [3H] DG uptake by Caco-2 cells. SME decreased the expression of HNF1α, HNF1β, and its targets SGLT1 and GLUT2, resulting in reduced glucose uptake by Caco-2 cells. In addition, our results revealed that dTMP plays an important role in suppressing the expression of intestinal glucose transporters.

Pharmacologic LDH inhibition redirects intratumoral glucose uptake and improves antitumor immunity in solid tumor models.

Tumor reliance on glycolysis is a hallmark of cancer. Immunotherapy is more effective in controlling glycolysis-low tumors lacking lactate dehydrogenase (LDH) due to reduced tumor lactate efflux and enhanced glucose availability within the tumor microenvironment (TME). LDH inhibitors (LDHi) reduce glucose uptake and tumor growth in preclinical models, but their impact on tumor-infiltrating T cells is not fully elucidated. Tumor cells have higher basal LDH expression and glycolysis levels compared with infiltrating T cells, creating a therapeutic opportunity for tumor-specific targeting of glycolysis. We demonstrate that LDHi treatment (a) decreases tumor cell glucose uptake, expression of the glucose transporter GLUT1, and tumor cell proliferation while (b) increasing glucose uptake, GLUT1 expression, and proliferation of tumor-infiltrating T cells. Accordingly, increasing glucose availability in the microenvironment via LDH inhibition leads to improved tumor-killing T cell function and impaired Treg immunosuppressive activity in vitro. Moreover, combining LDH inhibition with immune checkpoint blockade therapy effectively controls murine melanoma and colon cancer progression by promoting effector T cell infiltration and activation while destabilizing Tregs. Our results establish LDH inhibition as an effective strategy for rebalancing glucose availability for T cells within the TME, which can enhance T cell function and antitumor immunity.

Ameliorative Effects of Essential Oils on Diabetes Mellitus: A Review.

Diabetes mellitus (DM) is a metabolic disorder and is responsible for the death of more than 4.2 million people in 2019. Synthetic drugs for DM like metformin have been reported to induce numerous complications and side effects. Reports suggested that essential plant oil has been used as an herbal remedy to lower blood glucose levels. Essential oils (EOs) are complex combinations of small molecules obtained from plants via the process of steam distillation and several solvents. EOs have already shown great efficacy as antimicrobials, anti-inflammatory, hepatoprotective, and anti-hypertensive. This review aims to summarize some potential EOs that have been reported to have anti-diabetic activity both in preclinical and clinical aspects while summarizing the probable mechanism of action. The authors went through a vast number of articles from various scientific databases like Google Scholar, PubMed, and Web of Science. It was found that EO from a total of 20 plants has been pre-clinically investigated to have anti-diabetic potential. Besides this, clinical studies have reported the antidiabetic efficacy of EOs from Nigella sativa and Cuminum cyminum at different concentrations. Bioactive phytoconstituents like carvacrol, thymol, α- pinene, via . obtained from EOs ameliorate DM by inhibiting α-GLUC, α-amylase, lipase enzymes and increasing GLUT-4 expression, AKT phosphorylation, via . Although fewer in number, EOs from plant sources have demonstrated significant efficacy in DM. Proper elucidation of the anti-diabetic efficacy of the EOs may open up new avenues for drug discovery and development subjected to clinical studies.

Asiaticoside ameliorates type 2 diabetes mellitus in rats by modulating carbohydrate metabolism and regulating insulin signaling

Objective: To evaluate the effect of asiaticoside on streptozotocin (STZ) and nicotinamide (NAD)-induced carbohydrate metabolism abnormalities and deregulated insulin signaling pathways in rats. Methods: Asiaticoside (50 and 100 mg/kg body weight) was administered to STZ-NAD-induced diabetic rats for 45 days, and its effects on hyperglycaemic, carbohydrate metabolic, and insulin signaling pathway markers were examined. Results: Asiaticoside increased insulin production, lowered blood glucose levels, and enhanced glycolysis by improving hexokinase activity and suppressing glucose-6-phosphatase and fructose-1,6-bisphosphatase activities. Abnormalities in glycogen metabolism were mitigated by increasing glycogen synthase activity and gluconeogenesis was decreased by decreasing glycogen phosphorylase activity. Furthermore, asiaticoside upregulated the mRNA expressions of IRS-1, IRS-2, and GLUT4 in STZ-NAD-induced diabetic rats and restored the beta cell morphology to normal. Conclusions: Asiaticoside has the potential to ameliorate type 2 diabetes by improving glycolysis, gluconeogenesis, and insulin signaling pathways.

Effect of exogenous free Nε-(carboxymethyl)lysine on diabetes-associated cognitive dysfunction: neuroinflammation, and metabolic disorders

Diabetes-associated cognitive dysfunction has already been attracted considerable attention. Advanced glycation end products (AGEs) from daily diets are thought to be a vital contributor to the development of this diseases. However, the effect of one of the best-characterized exogenous AGEs Nε-(carboxymethyl)lysine (CML) on cognitive function is not fully reported. In the present study, diabetical Goto-Kakizaki (GK) rats were treated with free CML for 8-weeks. It was found that oral consumption of exogenous CML significantly aggravated diabetes-associated cognitive dysfunction in behavioral test. In details, exogenous CML increased levels of oxidative stress, promoted the activation of glial cells in the brain, up-regulated the release of inflammatory cytokines interleukin-6, inhibited the protein expression of the brain-derived neurotrophic factor and thus led to neuroinflammation. Furthermore, exogenous CML promoted the amyloidogenesis in the brain of GK rats, and inhibited the expression of GLUT4. Additionally, several tricarboxylic acid cycle and glutamate-glutamine/γ-aminobutyric acid cycle intermediates including pyruvate, succinic acid, glutamine, glutamate were significantly changed in brain of GK rats treated with exogenous free CML. In conclusion, exogenous free CML is a potentially noxious compounds led to aggravated diabetes-associated cognitive dysfunction which could be possibly explained by its effects on neuroinflammation, energy and neurotransmitter amino acid homeostasis.

Role of AMPK in Atrial Metabolic Homeostasis and Substrate Preference.

Atrial fibrillation is the most common clinical arrhythmia and may be due in part to metabolic stress. Atrial specific deletion of the master metabolic sensor, AMP-activated protein kinase (AMPK), induces atrial remodeling culminating in atrial fibrillation in mice, implicating AMPK signaling in the maintenance of atrial electrical and structural homeostasis. However, atrial substrate preference for mitochondrial oxidation and the role of AMPK in regulating atrial metabolism are unknown. Here, using LC-MS/MS methodology combined with infusions of [ 13 C 6 ]glucose and [ 13 C 4 ]β-hydroxybutyrate in conscious mice, we demonstrate that conditional deletion of atrial AMPK catalytic subunits shifts mitochondrial atrial metabolism away from fatty acid oxidation and towards pyruvate oxidation. LC-MS/MS-based quantification of acyl-CoAs demonstrated decreased atrial tissue content of long-chain fatty acyl-CoAs. Proteomic analysis revealed a broad downregulation of proteins responsible for fatty acid uptake (LPL, CD36, FABP3), acylation and oxidation. Atrial AMPK deletion reduced expression of atrial PGC1-α and downstream PGC1-α/PPARα/RXR regulated gene transcripts. In contrast, atrial [ 14 C]2-deoxyglucose uptake and GLUT1 expression increased with fasting in mice with AMPK deletion, while the expression of glycolytic enzymes exhibited heterogenous changes. Thus, these results highlight the crucial homeostatic role of AMPK in the atrium, with loss of atrial AMPK leading to downregulation of the PGC1-α/PPARα pathway and broad metabolic reprogramming with a loss of fatty acid oxidation, which may contribute to atrial remodeling and arrhythmia.

The Expression and Prognostic Value of Multiple Glucose Transporters in Cutaneous Melanoma.

Over-expression of glucose transporters (GLUTs), membrane proteins that facilitate glucose transport, has been implicated in cutaneous melanomas. Our prior studies have demonstrated increased expression of GLUT1 and GLUT3 in melanomas and their association with poorer prognosis. This study aimed to investigate the expression of GLUT isoforms 4 and 8 in melanocytic lesions, examine the co-expression status of multiple GLUTs, and evaluate their prognostic significance. We analyzed 171 melanocytic lesions (97 primary melanomas, 19 metastatic melanomas, and 55 nevi) using a tissue microarray and immunohistochemistry using antibodies against GLUT4 and GLUT8. Membranous expression of GLUTs was scored using a semi-quantitative method. A combined GLUT total score was generated by summing scores from GLUT1, GLUT3, GLUT4, and GLUT8 (including data from previous studies). A significant up-regulation of GLUT4 and GLUT8 expression was found in melanomas compared to nevi (p<0.0001 for both). Concurrent over-expression of multiple GLUTs was more prevalent in melanomas compared to nevi (p<0.0001), and it was also more frequent in metastatic melanomas compared to primary melanomas (p=0.047). Importantly, high total GLUT expression scores were significantly correlated with negative prognostic factors, such as ulceration and mitoses (p=0.03 and p=0.008 respectively). Additionally, Kaplan-Meier survival curves revealed that patients with elevated GLUT total score in their melanomas had a lower disease-specific survival (p=0.006). Furthermore, analysis of multiple GLUTs improved diagnostic sensitivity. Similar to GLUT1 and GLUT3, melanoma exhibits up-regulation of GLUT 4 and GLUT8 compared to nevi. Evaluation of multiple GLUT isoforms improves diagnostic and prognostic values.

Interplay of co-cultured chimeric adipose and gingival tissues exacerbates inflammatory dysfunction relevant to periodontal and metabolic conditions

Adipose tissue dysfunction is a key feature of metabolic syndrome, which increases the risk of periodontitis, an inflammatory disease induced by bacteria that affects the gingiva and other components of periodontal tissue. Recent studies indicate that molecules from inflamed periodontal tissue contribute to adipose tissue dysfunction. However, the cellular mechanisms and interactions between adipose tissue and gingiva driving the progression of metabolic and periodontal conditions remain unclear. To address this, we developed a chimeric (mouse/human) co-culture tissue model (which identifies the origins of species-specific cytokines) to investigate these interactions. Using tissue-specific functional cells and immunocytes, we constructed equivalents of adipose tissue (ATE) and gingiva (GTE), co-cultivating them under inflammatory conditions induced by bacterial endotoxin, lipopolysaccharide (LPS). Our findings showed that exposure to LPS resulted in a notable reduction in lipid accumulation, GLUT4 expression, and adiponectin secretion in ATE, along with increased macrophage colonies forming around lipid droplets, as well as elevated levels of triglyceride, leptin, and IL-6. In GTE, LPS triggered significant inflammatory responses, characterized by increased macrophage accumulation, elevated COX-2 expression, and heightened secretion of inflammatory cytokines. LPS also reduced epithelial thickness and the expression of keratin 19 and collagen IV, indicating impaired barrier function and gingival integrity. Co-culturing ATE with GTE exacerbated these LPS-induced harmful effects in both tissues. In conclusion, our findings suggest that interplay between gingiva and adipose tissue can intensify the inflammatory and dysfunctional changes caused by LPS. This co-culture tissue model offers a valuable tool for future studies on periodontitis and metabolic syndrome.

Cold Exposure Rejuvenates the Metabolic Phenotype of Panx1-/- Mice.

Pannexin1 (Panx1) ATP channels are important in adipocyte biology, potentially influencing energy storage and expenditure. We compared the metabolic phenotype of young (14 weeks old) and mature (20 weeks old) wild-type (WT) and Panx1-/- mice exposed or not to cold (6 °C) during 28 days, a condition promoting adipocyte browning. Young Panx1-/- mice weighed less and exhibited increased fat mass, improved glucose tolerance, and lower insulin sensitivity than WT mice. Their energy expenditure and respiratory exchange ratio (RER) were increased, and their fatty acid oxidation decreased. These metabolic effects were no longer observed in mature Panx1-/- mice. The exposure of mature mice to cold exacerbated their younger metabolic phenotype. The white adipose tissue (WAT) of cold-exposed Panx1-/- mice contained more small-sized adipocytes, but, in contrast to WT mice, white adipocytes did not increase their expression of Ucp1 nor of other markers of browning adipocytes. Interestingly, Glut4 expression was already enhanced in the WAT of young Panx1-/- mice kept at 22 °C as compared to WT mice. Thus, Panx1 deletion exerts overall beneficial metabolic effects in mice that are pre-adapted to chronic cold exposure. Panx1-/- mice show morphological characteristics of WAT browning, which are exacerbated upon cold exposure, an effect that appears to be associated with Ucp1-independent thermogenesis.

Müller Cells Harboring Exosomal lncRNA OGRU Modulate Microglia Polarization in Diabetic Retinopathy by Serving as miRNA Sponges.

Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus which is associated with visual loss and blindness worldwide. However, the effective treatments for both early- and late-stage DR remains lacking. A streptozotocin (STZ)-induced diabetic mice model and high glucose (HG)-treated Müller cell model were established. M1/M2 microglia polarization was assessed by immunofluorescence (IF) staining and flow cytometry. Expression of lncRNA OGRU, cytokines and other key molecules were detected by qRT-PCR or western blot. ELISA assay was employed to monitor cytokine secretion. Müller cell-derived exosomes were isolated and characterized by nanopartical tracking analysis (NTA), western blot and transmission electron microscopy (TEM), and exosome uptake assay was used to monitor the intercellular transport of exosomes. Associations among lncRNA-miRNA-mRNA networks were validated by RNA pull-down and RNA immunoprecipitation (RIP) and dual luciferase assays. Increased M1 polarization but decreased M2 polarization of retinal microglia were observed in DR mice. HG-treated Müller cell-derived exosomes transported OGRU into microglia and promoted microglia polarization toward M1 phenotype. Mechanistically, OGRU served as a competing endogenous RNA (ceRNA) for miR-320-3p, miR-221-3p and miR-574-5p to regulate AR, PFKFB3 and GLUT1 expression in microglia, respectively. Loss of miR-320-3p/miR-221-3p/miR-574-5p or reinforced AR/PFKFB3/GLUT1 abrogated OGRU silencing-mediated microglia polarization in vitro. In vivo studies further showed that OGRU/miR-320-3p/AR, OGRU/miR-221-3p/PFKFB3 and OGRU/miR-574-5p/GLUT1 axes regulated microglia polarization in DR mice. Collectively, Müller cells-derived exosomal OGRU regulated microglia polarization in DR via modulating OGRU/miR-320-3p/AR, OGRU/miR-221-3p/PFKFB3 and OGRU/miR-574-5p/GLUT1 axes.

Dietary supplementation of microencapsulated botanicals and organic acids enhances the expression and function of intestine epithelial digestive enzymes and nutrient transporters in broiler chickens

Organic acids and botanicals have shown protective effects on gut barrier and against inflammation in broilers. However, their effects on intestinal digestive enzymes and nutrients transporters expression and functions have not been fully studied. The objective of this study was to understand how a microencapsulated blend of botanicals and organic acids affected intestinal enzyme activities and nutrient transporters expression and functions in broilers. A total of 288 birds were assigned to a commercial control diet or diet supplemented with 500 g/MT (metric ton) of the microencapsulated additive. Growth performance was recorded weekly. At d 21 and d 42, jejunum and ileum were isolated for enzyme (maltase, sucrase, and aminopeptidase) and transporter (SGLT1, GLUT2, GLUT1, EAAT3, B0AT1, and PepT1) analyses. Jejunum specific nutrients (glucose, alanine, and glutamate) transport activities were evaluated by Ussing chamber. Protein expression of nutrient transporters in small intestine were measured in mucosa and brush-border membrane (BBM) samples by western blot. Intestinal gene expression of the transporters was determined by RT-PCR. Statistical analysis was performed using Student's t-test comparing the supplemented diet to the control. The feed efficiency was significantly improved through the study period in the supplemented group (P ≤ 0.05). Significant changes of intestinal histology were shown in both jejunum (P ≤ 0.10) and ileum (P ≤ 0.05) after 21 d of treatment. At d21, jejunal maltase activity was upregulated (P ≤ 0.10). The Ussing chamber transport of glucose and alanine was increased, which was in line with increased gene expression (GLUT2, GLUT1, EAAT3, and B0AT1) (P ≤ 0.10 and P ≤ 0.05, respectively) and BBMV protein levels (B0AT1, P < 0.10). At d21, ileal sucrase and maltase activities were upregulated (P ≤ 0.05). Increased expressions of GLUT1, EAAT3, and B0AT1 were observed in both mRNA and protein levels (P ≤ 0.05). Similar pattern of changes was also shown at d42 of age. Our results suggest that feeding microencapsulated additives improves intestinal nutrient digestion and transporter expression and function in broilers, thereby enhancing feed efficiency.

Role of Notch 1 signaling and glycolysis in the pathogenic mechanism of adenomyosis

To investigate the expressions of glycolysis-related factors and changes in Notch1 signaling in endometrial tissues of adenomyosis (AM) and Ishikawa cells to explore the pathogenesis of AM. Eutopic endometrial tissues were collected from 8 patients with AM and 8 patients with uterine fibroids matched for clinical characteristics (control group). The expressions of Notch1 signaling proteins and glycolysis-related factors in the collected tissues were detected using qRT-PCR and Western blotting, and the levels of glucose and lactic acid were determined. An Ishikawa cell model with lentivirus-mediated stable Notch1 overexpression was established for assessing cell survival rate with CCK-8 assay, cell migration and invasion abilities with Transwell migration and invasion assays, and glycolytic capacity by determining the extracellular acidification rate. Compared with those in the control group, the endometrial tissues in AM group showed significantly increased expression level of carbohydrate antigen 125 (CA125), increased mRNA expression levels of Notch1, HK2 and PDHA and protein expressions of Notch1, GLUT1, HK2, PKM and PDHA, lowered glucose level and increased lactate level. The Ishikawa cell models with stable Notch1 overexpression exhibited significantly increased cell survival rate with attenuated cell migration and invasion abilities and decreased glycolysis capacity and reserve. The Notch1 signaling pathway participates in the pathogenesis of AM possibly by regulating the proliferation, migration, invasion and glycolysis of endometrial cells.