High glucose levels decrease proliferation of cultured human fetal cells from placenta

Type 2 diabetes mellitus (T2DM) is a chronic, low-grade inflammation disease. T follicular helper (Tfh) cells and T cell immunoglobulin and mucin domain 3 (Tim-3) are implicated in many immune diseases. This study aims to explore whether Tim-3 expression on Tfh cells is associated with T2DM progression. White blood cells (WBCs) were harvested from 30 patients with T2DM and 20 healthy donors. The abundance of circulating Tfh cells (cTfh) and the frequency of Tim-3 were analyzed by flow cytometry. Levels of fasting plasma glucose (FPG), insulin, hemoglobin A1C (HbA1C), and fasting plasma C-peptide were measured. Body mass index (BMI) and diabetes duration were also recorded. Patients with T2DM had higher numbers of cTfh cells. In addition, cTfh cells showed a negative correlation with HbA1C and diabetes duration, a positive correlation with fasting plasma C-peptide. The frequency of Tim-3 on cTfh cells was higher among T2DM patients compared with healthy donors. The in vitro experiment showed that high glucose levels increased the abundance cTfh cells but had no effect on Tim-3 expression. Our results suggest that cTfh cells and associated Tim-3 frequency may contribute to the progression of T2DM, and high glucose levels may influence cTfh cells directly.

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Modulation of intestinal cholesterol absorption by high glucose levels: impact on cholesterol transporters, regulatory enzymes, and transcription factors

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.90376.2008 ◽

2008 ◽

Vol 295 (5) ◽

pp. G873-G885 ◽

Cited By ~ 45

Author(s):

Z. Ravid ◽

M. Bendayan ◽

E. Delvin ◽

A. T. Sane ◽

M. Elchebly ◽

...

Keyword(s):

Transcription Factors ◽

Protein Expression ◽

High Glucose ◽

Cholesterol Absorption ◽

Cholesterol Homeostasis ◽

Cholesterol Transport ◽

Intestinal Cholesterol Absorption ◽

Cholesterol Uptake ◽

Glucose Levels

Growing evidence suggests that the small intestine may contribute to excessive postprandial lipemia, which is highly prevalent in insulin-resistant/Type 2 diabetic individuals and substantially increases the risk of cardiovascular disease. The aim of the present study was to determine the role of high glucose levels on intestinal cholesterol absorption, cholesterol transporter expression, enzymes controlling cholesterol homeostasis, and the status of transcription factors. To this end, we employed highly differentiated and polarized cells (20 days of culture), plated on permeable polycarbonate filters. In the presence of [14C]cholesterol, glucose at 25 mM stimulated cholesterol uptake compared with Caco-2/15 cells supplemented with 5 mM glucose ( P < 0.04). Because combination of 5 mM glucose with 20 mM of the structurally related mannitol or sorbitol did not change cholesterol uptake, we conclude that extracellular glucose concentration is uniquely involved in the regulation of intestinal cholesterol transport. The high concentration of glucose enhanced the protein expression of the critical cholesterol transporter NPC1L1 and that of CD36 ( P < 0.02) and concomitantly decreased SR-BI protein mass ( P < 0.02). No significant changes were observed in the protein expression of ABCA1 and ABCG8, which act as efflux pumps favoring cholesterol export out of absorptive cells. At the same time, 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity was decreased ( P < 0.007), whereas ACAT activity remained unchanged. Finally, increases were noted in the transcription factors LXR-α, LXR-β, PPAR-β, and PPAR-γ along with a drop in the protein expression of SREBP-2. Collectively, our data indicate that glucose at high concentrations may regulate intestinal cholesterol transport and metabolism in Caco-2/15 cells, thus suggesting a potential influence on the cholesterol absorption process in Type 2 diabetes.

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High glucose and insulin in combination cause insulin receptor substrate-1 and -2 depletion and protein kinase B desensitisation in primary cultured rat adipocytes: possible implications for insulin resistance in type 2 diabetes

Acta Endocrinologica ◽

10.1530/eje.0.1480157 ◽

2003 ◽

Vol 148 (1) ◽

pp. 157-167 ◽

Cited By ~ 43

Author(s):

J Buren ◽

HX Liu ◽

J Lauritz ◽

JW Eriksson

Keyword(s):

Glucose Uptake ◽

High Glucose ◽

Insulin Treatment ◽

Insulin Signalling ◽

Binding Capacity ◽

Insulin Binding ◽

Rat Adipocytes ◽

Glucose Levels ◽

High Insulin ◽

The Right

OBJECTIVE: The purpose of this study was to investigate the cellular effects of long-term exposure to high insulin and glucose levels on glucose transport and insulin signalling proteins. DESIGN AND METHODS: Rat adipocytes were cultured for 24 h in different glucose concentrations with 10(4) microU/ml of insulin or without insulin. After washing, (125)I-insulin binding, basal and acutely insulin-stimulated d-[(14)C]glucose uptake, and insulin signalling proteins and glucose transporter 4 (GLUT4) were assessed. RESULTS: High glucose (15 and 25 mmol/l) for 24 h induced a decrease in basal and insulin-stimulated glucose uptake compared with control cells incubated in low glucose (5 or 10 mmol/l). Twenty-four hours of insulin treatment decreased insulin binding capacity by approximately 40%, and shifted the dose-response curve for insulin's acute effect on glucose uptake 2- to 3-fold to the right. Twenty-four hours of insulin treatment reduced basal and insulin-stimulated glucose uptake only in the presence of high glucose (by approximately 30-50%). At high glucose, insulin receptor substrate-1 (IRS-1) expression was downregulated by approximately 20-50%, whereas IRS-2 was strongly upregulated by glucose levels of 10 mmol/l or more (by 100-400%). Insulin treatment amplified the suppression of IRS-1 when combined with high glucose and also IRS-2 expression was almost abolished. Twenty-four hours of treatment with high glucose or insulin, alone or in combination, shifted the dose-response curve for insulin's effect to acutely phosphorylate protein kinase B (PKB) to the right. Fifteen mmol/l glucose increased GLUT4 in cellular membranes (by approximately 140%) compared with 5 mmol/l but this was prevented by a high insulin concentration. CONCLUSIONS: Long-term exposure to high glucose per se decreases IRS-1 but increases IRS-2 content in rat adipocytes and it impairs glucose transport capacity. Treatment with high insulin downregulates insulin binding capacity and, when combined with high glucose, it produces a marked depletion of IRS-1 and -2 content together with an impaired sensitivity to insulin stimulation of PKB activity. These mechanisms may potentially contribute to insulin resistance in type 2 diabetes.

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High glucose levels inhibit focal adhesion kinase-mediated wound healing of rat peritoneal mesothelial cells

Kidney International ◽

10.1046/j.1523-1755.2003.00772.x ◽

2003 ◽

Vol 63 (2) ◽

pp. 722-731 ◽

Cited By ~ 34

Author(s):

Masahito Tamura ◽

Akihiko Osajima ◽

Shingo Nakayamada ◽

Hirofumi Anai ◽

Narutoshi Kabashima ◽

...

Keyword(s):

Wound Healing ◽

Focal Adhesion Kinase ◽

Focal Adhesion ◽

High Glucose ◽

Mesothelial Cells ◽

Peritoneal Mesothelial Cells ◽

Glucose Levels

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High glucose levels reduce fatty acid oxidation and increase triglyceride accumulation in human placenta

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00032.2013 ◽

2013 ◽

Vol 305 (2) ◽

pp. E205-E212 ◽

Cited By ~ 45

Author(s):

Francisco Visiedo ◽

Fernando Bugatto ◽

Viviana Sánchez ◽

Irene Cózar-Castellano ◽

Jose L. Bartha ◽

...

Keyword(s):

Fatty Acid ◽

High Glucose ◽

De Novo ◽

Acid Synthesis ◽

Acid Oxidation ◽

Glucose Levels ◽

Triglyceride Accumulation ◽

Triglyceride Content ◽

Low Glucose ◽

Cpt I

Placentas of women with gestational diabetes mellitus (GDM) exhibit an altered lipid metabolism. The mechanism by which GDM is linked to alterations in placental lipid metabolism remains obscure. We hypothesized that high glucose levels reduce mitochondrial fatty acid oxidation (FAO) and increase triglyceride accumulation in human placenta. To test this hypothesis, we measured FAO, fatty acid esterification, de novo fatty acid synthesis, triglyceride levels, and carnitine palmitoyltransferase activities (CPT) in placental explants of women with GDM or no pregnancy complication. In women with GDM, FAO was reduced by ∼30% without change in mitochondrial content, and triglyceride content was threefold higher than in the control group. Likewise, in placental explants of women with no complications, high glucose levels reduced FAO by ∼20%, and esterification increased linearly with increasing fatty acid concentrations. However, de novo fatty acid synthesis remained unchanged between high and low glucose levels. In addition, high glucose levels increased triglyceride content approximately twofold compared with low glucose levels. Furthermore, etomoxir-mediated inhibition of FAO enhanced esterification capacity by ∼40% and elevated triglyceride content 1.5-fold in placental explants of women, with no complications. Finally, high glucose levels reduced CPT I activity by ∼70% and phosphorylation levels of acetyl-CoA carboxylase by ∼25% in placental explants of women, with no complications. We reveal an unrecognized regulatory mechanism on placental fatty acid metabolism by which high glucose levels reduce mitochondrial FAO through inhibition of CPT I, shifting flux of fatty acids away from oxidation toward the esterification pathway, leading to accumulation of placental triglycerides.

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The effect of high glucose on lipid metabolism in the human placenta

Scientific Reports ◽

10.1038/s41598-019-50626-x ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 5

Author(s):

Charlotte H. Hulme ◽

Anna Nicolaou ◽

Sharon A. Murphy ◽

Alexander E. P. Heazell ◽

Jenny E. Myers ◽

...

Keyword(s):

Fatty Acid ◽

Lipid Metabolism ◽

High Glucose ◽

Fatty Acid Uptake ◽

Fatty Acid Transport ◽

Acid Uptake ◽

Obese Women ◽

Lipid Transfer ◽

Glucose Levels ◽

Fatty Acid Transport Proteins

Abstract Diabetes mellitus (DM) during pregnancy can result in fetal overgrowth, likely due to placental dysfunction, which has health consequences for the infant. Here we test our prediction from previous work using a placental cell line that high glucose concentrations affect placental lipid metabolism. Placentas from women with type 1 (n = 13), type 2 (n = 6) or gestational (n = 12) DM, BMI-matched to mothers without DM (n = 18), were analysed for lipase and fatty acid transport proteins and fatty acid and triglyceride content. Explants from uncomplicated pregnancies (n = 6) cultured in physiological or high glucose were similarly analysed. High glucose levels did not alter placental lipase or transporter expression or the profile and abundance of fatty acids, but triglyceride levels were higher (p < 0.05), suggesting reduced β- oxidation. DM did not affect placental protein expression or fatty acid profile. Triglyceride levels of placentas from mothers with pre-existing DM were similar to controls, but higher in obese women with gestational DM. Maternal hyperglycemia may not affect placental fatty acid uptake and transport. However, placental β-oxidation is affected by high glucose and reduced in a subset of women with DM. Abnormal placental lipid metabolism could contribute to increased maternal-fetal lipid transfer and excess fetal growth in some DM pregnancies.

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AGEs and Glucose Levels Modulate Type I and III Procollagen mRNA Synthesis in Dermal Fibroblasts Cells Culture

Experimental Diabetes Research ◽

10.1155/2008/473603 ◽

2008 ◽

Vol 2008 ◽

pp. 1-7 ◽

Cited By ~ 24

Author(s):

Serban Iren Andreea ◽

Costache Marieta ◽

Dinischiotu Anca

Keyword(s):

Extracellular Matrix ◽

High Glucose ◽

Dermal Fibroblasts ◽

Type I ◽

Dependent Manner ◽

Human Dermal Fibroblasts ◽

Mrna Synthesis ◽

Quantitative Real Time Pcr ◽

Glucose Levels ◽

Dose Dependent

In the dermis, fibroblasts play an important role in the turnover of the dermal extracellular matrix. Collagen I and III, the most important dermal proteins of the extracellular matrix, are progressively altered during ageing and diabetes. For mimicking diabetic conditions, the cultured human dermal fibroblasts were incubated with increasing amounts of AGE-modified BSA andD-glucose for 24 hours. The expression of procollagenα2(I) and procollagenα1(III) mRNA was analyzed by quantitative real-time PCR. Our data revealed that the treatment of fibroblasts with AGE-modified BSA upregulated the expression of procollagenα2(I) and procollagenα1(III) mRNA in a dose-dependent manner. High glucose levels mildly induced a profibrogenic pattern, increasing the procollagenα2(I) mRNA expression whereas there was a downregulation tendency of procollagenα1(III) mRNA.

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Bottom-up proteomics analysis of the secretome of murine islets of Langerhans in elevated glucose levels

The Analyst ◽

10.1039/c6an02268e ◽

2017 ◽

Vol 142 (2) ◽

pp. 284-291 ◽

Cited By ~ 1

Author(s):

Andrew Schmudlach ◽

Jeremy Felton ◽

Robert T. Kennedy ◽

Norman J. Dovichi

Keyword(s):

Type 2 Diabetes ◽

Endoplasmic Reticulum ◽

Endoplasmic Reticulum Stress ◽

Oxidative Damage ◽

Islets Of Langerhans ◽

High Glucose ◽

Proteomics Analysis ◽

Glucose Levels ◽

Elevated Glucose

Glucotoxicity is a causative agent of type-2 diabetes, where high glucose levels damage the islets of Langerhans resulting in oxidative damage and endoplasmic reticulum stress.

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