scholarly journals Elevated glucose acts directly on osteocytes to increase sclerostin expression in diabetes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Donna M. Pacicca ◽  
Tammy Brown ◽  
Dara Watkins ◽  
Karen Kover ◽  
Yun Yan ◽  
...  
Keyword(s):  
Bone Quality ◽  
High Glucose ◽  
Negative Impact ◽  
Negative Regulator ◽  
Diabetic Rat ◽  
Diabetic Patients ◽  
Bone Homeostasis ◽  
Glucose Levels ◽  
Elevated Glucose

AbstractBone quality in diabetic patients is compromised, leading to weaker bones and increased fracture risk. However, the mechanism by which this occurs in diabetic bone remains to be fully elucidated. We hypothesized that elevated glucose and glucose variation would affect the function of osteocytes, essential regulators of bone homeostasis and quality. To first test this hypothesis, we used the IDG-SW3 osteocyte-like cell line to examine the effects of glucose levels on osteocyte function and viability in vitro. We confirmed our in vitro findings using the in vivo streptozotocin-induced (STZ) diabetic rat model and ex-vivo cultured osteocytes from these rats. IDG-SW3 cells cultured under high glucose conditions displayed significantly increased Sost mRNA(100-fold) and sclerostin protein, a negative regulator of bone formation(5000-fold), compared to cells in control media. mRNA expression of osteoblast markers such as Osx, Ocn and Col1a1 was unaffected by glucose. Factors associated with osteoclast activation were affected by glucose, with Rankl being upregulated by low glucose. Opg was also transiently upregulated by high glucose in mature IDG-SW3 cells. Induction of diabetes in Sprague-Dawley rats via a single dose of STZ (70 mg/kg) resulted in elevated maximum glucose and increased variability compared to control animals (670/796 vs. 102/142 mg/dL). This was accompanied by increased Sost/sclerostin expression in the osteocytes of these animals. These results show that glucose levels directly regulate osteocyte function through sclerostin expression and suggest a potential mechanism for the negative impact of diabetes on bone quality.

Hyperglycemia exacerbates cadmium-induced glomerular nephrosis

2021 ◽  
pp. 074823372110378
Author(s):  
Mengyang Li ◽  
Xiuxiu Liu ◽  
Zengli Zhang
Keyword(s):  
High Glucose ◽  
Saline Control ◽  
In Vivo Models ◽  
Nitrogen Levels ◽  
Glucose Levels ◽  
Elevated Glucose ◽  
Low Glucose ◽  
Cd Exposure

Current research suggests that cadmium (Cd) exposure may be associated with the progression of diabetic nephropathy; however, the details of this relationship are insufficiently understood. The present study investigated the effects of elevated glucose on Cd-induced toxicity to glomerular cells using in vitro and in vivo models, and it demonstrated that Cd exposure and the hyperglycemia of diabetes acting together increased the risk of developing glomerular nephrosis . In vitro, human podocytes were exposed to a DMEM low-glucose media without (control), or with Cd (as CdCl2), or a high-glucose media plus Cd. The CCK-8, ROS, apoptosis, and mitochondrial transmembrane potential (ΔΨm) assays showed that human podocytes exposed to Cd in a high-glucose media had greater degrees of injury compared with cells treated with Cd at low (euglycemic)-glucose levels. In vivo, diabetic hyperglycemia was induced by streptozotocin in 8-week-old male C57BL/6 mice to which either CdCl2 or saline (control) was intraperitoneally injected twice weekly for 24 weeks. Compared with euglycemic saline-treated controls, the diabetic mice exposed to Cd demonstrated decreased body weight and increased blood urea nitrogen levels along with histopathological renal architecture changes including collagen fiber accumulation. The results of this study supported the hypothesis that hyperglycemia plus Cd exposure increases the risk of damage to glomerular podocytes compared with Cd exposure in euglycemia.

scholarly journals High Glucose-Mediated Cytokine Regulation in Gingival Fibroblasts and THP-1 Macrophage: a Possible Mechanism of Severe Periodontitis with Diabetes

2018 ◽  
Vol 50 (3) ◽  
pp. 973-986 ◽  
Author(s):  
Jung-Hwan Lew ◽  
Koji Naruishi ◽  
Yukari Kajiura ◽  
Yasufumi Nishikawa ◽  
Takahisa Ikuta ◽  
...  
Keyword(s):  
High Glucose ◽  
Gingival Crevicular Fluid ◽  
In Vitro Study ◽  
Inflammatory Factors ◽  
Diabetic Patients ◽  
Gingival Fibroblasts ◽  
Cross Sectional ◽  
Periodontal Tissues ◽  
Severe Periodontitis

Background/Aims: Diabetic patients are susceptible to severe periodontitis, but the precise mechanism is not fully understood. Aim of this study was to explore the biological pathogenesis of severe periodontitis in diabetic patients focusing on the crosstalk of human gingival fibroblasts (HGFs) and macrophages. Methods: A total of 70 periodontitis patients with or without diabetes mellitus (DM) were enrolled, and the statistical relationships of diabetic conditions to the periodontal inflammatory parameters were examined by cross-sectional study. In in vitro study, HGFs cell line CRL-2014® (ATCC) and differentiated THP-1 macrophages were cultured with normal glucose (NG: 5.5 mM) or high glucose (HG: 25 mM) condition, and treated with indicated inflammatory factors such as calprotectin (CPT), interleukin (IL)-1β and IL-6. To examine the effects of HG on soluble IL-6 receptor (sIL-6R) production in THP-1 macrophages, the supernatants were collected and the sIL-6R levels were measured by ELISA. To examine the effects of HG on IL-1β or IL-6-induced matrix metalloproteinase (MMPs) production in HGFs, the supernatants were collected. Levels of MMP-1 and tissue inhibitor of MMP-1 (TIMP-1) were measured by ELISA. Finally, after conditioned medium (CM) from THP-1 macrophages cultured with NG or HG conditions was collected, HGFs were treated with the CM. The supernatants were collected 24 hours later and the levels of MMP-1 and TIMP-1 were measured. To examine the specific effects of IL-1β contained in CM on MMP-1 and TIMP-1 production in HGFs, IL-1 receptor antagonist (IL-1ra) was used. Results: There were statistical correlation between IL-1β and sIL-6R levels in gingival crevicular fluid (GCF) and HbA1c in periodontitis patients with DM (IL-1β: P=0.035, sIL-6R: P=0.040). HG and CPT significantly induced sIL-6R production in THP-1 macrophages. HG significantly enhanced IL-1β or IL-6/sIL-6R-induced MMP-1 production in HGFs. The increase of MMP-1 by both IL-1β and IL-6/sIL-6R was significantly inhibited by specific ERK or IκB inhibitors. Corresponding to the regulation of MMP-1 production, HG condition increased the phosphorylation of p44/42 MAPK and IκBα in HGFs treated with IL-1β or IL-6/sIL-6R. Finally, MMP-1 production in HGFs cultured with HG increased significantly by CM from THP-1 macrophages cultured with HG. The induction of MMP-1 by the CM from THP-1 macrophages cultured with HG was significantly inhibited by dose dependent of IL-1ra in HGFs cultured with HG. Conclusion: Diabetic conditions such as HG induce IL-1β and sIL-6R production from macrophages in inflammatory periodontal tissues and may exacerbate the periodontitis synergistically via MMP-1 production from HGFs.

scholarly journals High glucose induces early senescence in adipose-derived stem cells by accelerating p16 and mTOR

2019 ◽  
Vol 6 (6) ◽  
pp. 3213-3221
Author(s):  
Hieu Liem Pham ◽  
Phuc Van Pham
Keyword(s):  
Stem Cells ◽  
High Glucose ◽  
Glucose Concentration ◽  
Culture Medium ◽  
Diabetic Patients ◽  
Adipose Derived Stem Cells ◽  
Differentiation Potential ◽  
Normal Glucose

Introduction: The senescence of stem cells is the primary reason that causes aging of stem cell-containing tissues. Some hypotheses have suggested that high glucose concentration in diabetic patients is the main factor that causes senescence of cells in those patients. This study aimed to evaluate the effects of high glucose concentrations on the senescence of adipose-derived stem cells (ADSCs). Methods: ADSCs were isolated and expanded from human adipose tissues. They were characterized and confirmed as mesenchymal stem cells (MSCs) by expression of surface markers, their shape, and in vitro differentiation potential. They were then cultured in 3 different media- that contained 17.5 mM, 35 mM, or 55 mM of D-glucose. The senescent status of ADSCs was recorded by the expression of the enzyme beta-galactosidase, cell proliferation, and doubling time. Real-time RT-PCR was used to evaluate the expression of p16, p21, p53 and mTOR. Results: The results showed that high glucose concentrations (35 mM and 55 mM) in the culture medium induced senescence of human ADSCs. The ADSCs could progress to the senescent status quicker than those cultured in the lower glucose-containing medium (17.5 mM). The senescent state was related to the up-regulation of p16 and mTOR genes. Conclusion: These results suggest that high glucose in culture medium can trigger the expression of p16 and mTOR genes which cause early senescence in ADSCs. Therefore, ADSCs should be cultured in low glucose culture medium, or normal glucose concentration, to extend their life in vitro as well as in vivo.  

scholarly journals Effect of Bioconditioning on Surface Characteristics of Periodontally-affected Roots of Diabetic Patients

2014 ◽  
Vol 5 (2) ◽  
pp. 81-86
Author(s):  
Hossam A Eid ◽  
Khalid M Abdelaziz ◽  
Refaat A Eid
Keyword(s):  
Citric Acid ◽  
Chronic Periodontitis ◽  
Negative Impact ◽  
Surface Characteristics ◽  
Diabetic Patients ◽  
Type Ii ◽  
Sem Images ◽  
Root Surfaces ◽  
Tetracycline Hcl

ABSTRACT Objective Advanced glycosylated end products (AGEs) in type II diabetic patients are usually precipitated on the periodontallyaffected root surfaces. The presence of periodontopathic microbes, at the same time, may also add a negative impact on the prognosis of the regenerative periodontal surgery. This in vitro study aimed to evaluate the effect of chemical conditioning on surface characteristics of periodontally-affected roots of diabetic patients. Methods Three groups (n = 25) of freshly-extracted teeth were collected from the outpatient clinics, College of Dentistry, King Khalid University. In group 1, teeth were collected from healthy individuals for orthodontic purpose. Teeth of group 2 were collected from healthy patients with chronic periodontitis, while those of group 3 were collected from diabetic patients with chronic periodontitis. Roots of the collected teeth were examined using the scanning electron microscope (SEM) before and after mechanical surface planning and chemical treatment using normal saline, EDTA gel, Tetracycline HCL (TC) or citric acid (CA) each for 4 minutes (n = 5 from each group). Results Interpretation of SEM images revealed undesirable etching effect of the chemicals used on the surfaces of healthy roots. Although EDTA showed an effective cleanse of the smear debris, it seemed to have no power on surface cuticles existed on roots of diabetic individuals. Tetracycline HCl provided acceptable conditioning of periodontally-affected root surfaces. Citric acid showed a powerful removal of both smear debris and cuticle layers off the periodontally-affected roots of diabetic individuals. Conclusion Topical application of EDTA, TC or CA shows sensible effect on the periodontally affected root surfaces. However, each of these chemicals exhibits different conditioning power. Citric acid is a promising agent to biomodify the periodontally-affected root surfaces of diabetic patients. Clinical relevance Citric acid is an acceptable biomodifier for the periodontally-affected root surfaces. This approach may improve the prognosis of periodontal therapies especially in type II diabetic patients. How to cite this article Abdelaziz KM, Eid HA, Eid RA. Effect of Bioconditioning on Surface Characteristics of Periodontally- affected Roots of Diabetic Patients. World J Dent 2014;5(2):81-86.

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

The Analyst ◽  
2017 ◽  
Vol 142 (2) ◽  
pp. 284-291 ◽  
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.

scholarly journals High-glucose-induced miR-214-3p inhibits BMSCs osteogenic differentiation in type 1 diabetes mellitus

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Rongze Wang ◽  
Yuanxu Zhang ◽  
Fujun Jin ◽  
Gongchen Li ◽  
Yao Sun ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 1 Diabetes ◽  
Type 1 Diabetes Mellitus ◽  
Osteogenic Differentiation ◽  
High Glucose ◽  
Bone Homeostasis ◽  
Marrow Mesenchymal Stem Cells

Abstract Type 1 diabetes mellitus (T1DM) is an autoimmune insulin-dependent disease associated with destructive bone homeostasis. Accumulating evidence has proven that miRNAs are widely involved in the regulation of bone homeostasis. However, whether miRNAs also regulate osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in T1DM mice is under exploration. In this study, miRNA microarray was utilized to screen the differentially expressed miRNAs, which uncovered that miR-214-3p potentially inhibited BMSCs osteogenic differentiation in T1DM mice. We found that high glucose suppressed BMSCs osteogenic differentiation with significant elevation of the miR-214-3p expression. Further study found that the osteogenic differentiation of BMSCs was inhibited by AgomiR-214-3p while enhanced by AntagomiR-214-3p in BMSCs supplemented with high glucose. Moreover, we found that miR-214-3p knockout T1DM mice were resistant to high-glucose-induced bone loss. These results provide a novel insight into an inhibitory role of high-glucose-induced miR-214-3p in BMSCs osteogenic differentiation both in vitro and in vivo. Molecular studies revealed that miR-214-3p inhibits BMSCs osteogenic differentiation by targeting the 3′-UTR of β-catenin, which was further corroborated in human bone specimens and BMSCs of T1DM patients. Taken together, our study discovered that miR-214-3p is a pivotal regulator of BMSCs osteogenic differentiation in T1DM mice. Our findings also suggest that miR-214-3p could be a potential target in the treatment of bone disorders in patients with T1DM.

scholarly journals The Intracellular Growth of M. tuberculosis Is More Associated with High Glucose Levels Than with Impaired Responses of Monocytes from T2D Patients

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Martha Torres ◽  
María Teresa Herrera ◽  
Guadalupe Fabián-San-Miguel ◽  
Yolanda Gonzalez
Keyword(s):  
High Glucose ◽  
Healthy Subjects ◽  
Intrinsic Factor ◽  
Growth Control ◽  
Intracellular Growth ◽  
Glucose Levels ◽  
Basal Expression ◽  
Ligand Stimulation

Diabetes mellitus, a metabolic disease characterized by hyperglycemia and poor glucose control, is a risk factor for Mycobacterium tuberculosis (M. tuberculosis) infection and the development of active tuberculosis. To evaluate whether M. tuberculosis infection susceptibility is associated with an intrinsic factor in monocytes from type 2 diabetes (T2D) patients or it is associated with hyperglycemia per se, we analyzed TLR-2 and TLR-4 expression by flow cytometry and the cytokines IL-1β, IL-6, IL-8, IL-10, and TNF-α by cytometric bead array assays, either stimulated with TLR-2 and TLR-4 ligands or infected with M. tuberculosis in the whole blood from T2D patients (n=43) and healthy subjects (n=26) or in CD14+ monocytes from healthy subjects cultured in high glucose (HG) (30 mM). The intracellular growth of M. tuberculosis was evaluated by CFU counts at 0, 1, and 3 days in both monocytes from T2D patients and monocytes from healthy subjects cultured in HG. We did not find significant differences in TLR expression, cytokine production, or growth of M. tuberculosis in monocytes from T2D patients compared with those in monocytes from healthy subjects. Despite these results, in vitro assays of monocytes cultured with 30 mM glucose led to significantly increased TLR-2 and TLR-4 basal expression compared to those of monocytes cultured with 11 mM glucose (P<0.05). Conversely, the production of IL-6 by TLR-2 ligand stimulation, of IL-1β, IL-6, and IL-8 by TLR-4 ligand stimulation, and of IL-8 by M. tuberculosis infection significantly decreased in monocytes cultured in HG (P<0.05). Additionally, the intracellular survival of M. tuberculosis increased in monocytes in HG after day 3 of culture (P<0.05). In conclusion, HG decreased IL-8 production and the intracellular growth control of M. tuberculosis by monocytes, supporting the hypothesis that hyperglycemia plays an important role in the impaired immune responses to M. tuberculosis in patients with T2D.

scholarly journals CYLD Deubiquitinase Negatively Regulates High Glucose-Induced NF-κB Inflammatory Signaling in Mesangial Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Yanhui Li ◽  
Wei Huang ◽  
Youhua Xu ◽  
Luping Zhou ◽  
Yaling Liang ◽  
...  
Keyword(s):  
High Glucose ◽  
Mesangial Cells ◽  
Pressure Control ◽  
Ubiquitin Proteasome System ◽  
Negative Regulator ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Inflammatory Signaling ◽  
Mediated Effects ◽  
Elevated Glucose

Nuclear factor-kappa B (NF-κB) is the key part of multiple signal transduction of inflammation in the pathogenesis of diabetic nephropathy (DN). The ubiquitin-proteasome system is extensively involved in the regulation of the NF-κB pathway. Cylindromatosis (CYLD) has deubiquitinase activity and acts as a negative regulator of the NF-κB signaling pathway. However, the association between CYLD and NF-κB inflammatory signaling in DN is unclear. In the present study, mouse glomerular mesangial cells (GMCs) and rat GMCs were stimulated by elevated concentrations of glucose (10, 20, and 30 mmol/L high glucose) or mannitol as the osmotic pressure control. CYLD was overexpressed or suppressed by transfection with a CYLD expressing vector or CYLD-specific siRNA, respectively. Our data showed that high glucose significantly inhibited the protein and mRNA expression of CYLD in a dose- and time-dependent manner (both p<0.05). siRNA-mediated knockdown CYLD facilitated the high glucose-induced activation of NF-κB signaling and triggered the release of MCP-1, IL-6, and IL-8 (all p<0.05). However, these high glucose-mediated effects were blunted by overexpression of CYLD (p<0.05). The present results support the involvement of CYLD in the regulation of NF-κB inflammatory signaling induced by elevated glucose, implicating CYLD as a potential therapeutic target of DN.

Cell-wide analysis of secretory granule dynamics in three dimensions in living pancreatic β-cells: evidence against a role for AMPK-dependent phosphorylation of KLC1 at Ser517/Ser520 in glucose-stimulated insulin granule movement

2010 ◽  
Vol 38 (1) ◽  
pp. 205-208 ◽  
Author(s):  
Angela McDonald ◽  
Sarah Fogarty ◽  
Isabelle Leclerc ◽  
Elaine V. Hill ◽  
D. Grahame Hardie ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Glutathione Transferase ◽  
Three Dimensions ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Glucose Levels ◽  
Insulin Granules ◽  
Elevated Glucose ◽  
Glucose Stimulated Insulin Secretion

Glucose-stimulated insulin secretion from pancreatic β-cells requires the kinesin-1/Kif5B-mediated transport of insulin granules along microtubules. 5′-AMPK (5′-AMP-activated protein kinase) is a heterotrimeric serine/threonine kinase which is activated in β-cells at low glucose concentrations, but inhibited as glucose levels increase. Active AMPK blocks glucose-stimulated insulin secretion and the recruitment of insulin granules to the cell surface, suggesting motor proteins may be targets for this kinase. While both kinesin-1/Kif5B and KLC1 (kinesin light chain-1) contain consensus AMPK phosphorylation sites (Thr693 and Ser520, respectively) only recombinant GST (glutathione transferase)–KLC1 was phosphorylated by purified AMPK in vitro. To test the hypothesis that phosphorylation at this site may modulate kinesin-1-mediated granule movement, we developed an approach to study the dynamics of all the resolvable granules within a cell in three dimensions. This cell-wide approach revealed that the number of longer excursions (>10 μm) increased significantly in response to elevated glucose concentration (30 versus 3 mM) in control MIN6 β-cells. However, similar changes were seen in cells overexpressing wild-type KLC1, phosphomimetic (S517D/S520D) or non-phosphorylatable (S517A/S520A) mutants of KLC1. Thus, changes in the phosphorylation state of KLC1 at Ser517/Ser520 seem unlikely to affect motor function.

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