scholarly journals Epigenetic Changes in Endothelial Progenitors as a Possible Cellular Basis for Glycemic Memory in Diabetic Vascular Complications

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Poojitha Rajasekar ◽  
Christina L. O’Neill ◽  
Lydia Eeles ◽  
Alan W. Stitt ◽  
Reinhold J. Medina
Keyword(s):  
Glycemic Control ◽  
Vascular Complications ◽  
Disease Process ◽  
Diabetic Patients ◽  
Negative Consequences ◽  
Diabetic Vascular Complications ◽  
Endothelial Progenitors ◽  
Glycemic Memory

The vascular complications of diabetes significantly impact the quality of life and mortality in diabetic patients. Extensive evidence from various human clinical trials has clearly established that a period of poor glycemic control early in the disease process carries negative consequences, such as an increase in the development and progression of vascular complications that becomes evident many years later. Importantly, intensive glycemic control established later in the disease process cannot reverse or slow down the onset or progression of diabetic vasculopathy. This has been named the glycemic memory phenomenon. Scientists have successfully modelled glycemic memory using variousin vitroandin vivosystems. This review emphasizes that oxidative stress and accumulation of advanced glycation end products are key factors driving glycemic memory in endothelial cells. Furthermore, various epigenetic marks have been proposed to closely associate with vascular glycemic memory. In addition, we comment on the importance of endothelial progenitors and their role as endogenous vasoreparative cells that are negatively impacted by the diabetic milieu and may constitute a “carrier” of glycemic memory. Considering the potential of endothelial progenitor-based cytotherapies, future studies on their glycemic memory are warranted to develop epigenetics-based therapeutics targeting diabetic vascular complications.

scholarly journals S-glutathionylation: relevance in diabetes and potential role as a biomarker

2013 ◽  
Vol 394 (10) ◽  
pp. 1263-1280 ◽  
Author(s):  
Francisco J. Sánchez-Gómez ◽  
Cristina Espinosa-Díez ◽  
Megha Dubey ◽  
Madhu Dikshit ◽  
Santiago Lamas
Keyword(s):  
Oxidative Stress ◽  
Vascular Complications ◽  
Redox Balance ◽  
Diabetic Patients ◽  
Sulfenic Acid ◽  
Diabetic Vascular Complications ◽  
Main Regulator ◽  
Species Production

Abstract Glutathione is considered the main regulator of redox balance in the cellular milieu due to its capacity for detoxifying deleterious molecules. The oxidative stress induced as a result of a variety of stimuli promotes protein oxidation, usually at cysteine residues, leading to changes in their activity. Mild oxidative stress, which may take place in physiological conditions, induces the reversible oxidation of cysteines to sulfenic acid form, while pathological conditions are associated with higher rates of reactive oxygen species production, inducing the irreversible oxidation of cysteines. Among these, neurodegenerative disorders, cardiovascular diseases and diabetes have been proposed to be pathogenetically linked to this state. In diabetes-associated vascular complications, lower levels of glutathione and increased oxidative stress have been reported. S-glutathionylation has been proposed as a posttranslational modification able to protect proteins from over-oxidizing environments. S-glutathionylation has been identified in proteins involved in diabetic models both in vitro and in vivo. In all of them, S-glutathionylation represents a mechanism that regulates the response to diabetic conditions, and has been described to occur in erythrocytes and neutrophils from diabetic patients. However, additional studies are necessary to discern whether this modification represents a biomarker for the early onset of diabetic vascular complications.

scholarly journals Diabetic Cataract—Pathogenesis, Epidemiology and Treatment

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Andreas Pollreisz ◽  
Ursula Schmidt-Erfurth
Keyword(s):  
Experimental Studies ◽  
Disease Process ◽  
Basic Research ◽  
Polyol Pathway ◽  
Population Based ◽  
Diabetic Patients ◽  
Diabetic Cataract ◽  
Cataract Development

Cataract in diabetic patients is a major cause of blindness in developed and developing countries. The pathogenesis of diabetic cataract development is still not fully understood. Recent basic research studies have emphasized the role of the polyol pathway in the initiation of the disease process. Population-based studies have greatly increased our knowledge concerning the association between diabetes and cataract formation and have defined risk factors for the development of cataract. Diabetic patients also have a higher risk of complications after phacoemulsification cataract surgery compared to nondiabetics. Aldose-reductase inhibitors and antioxidants have been proven beneficial in the prevention or treatment of this sightthreatening condition in in vitro and in vivo experimental studies. This paper provides an overview of the pathogenesis of diabetic cataract, clinical studies investigating the association between diabetes and cataract development, and current treatment of cataract in diabetics.

scholarly journals An analytical study of the prevalence and prescribed pattern vascular complication for type II diabetic patient in Indian tertiary care hospitals

2020 ◽  
Vol 11 (SPL4) ◽  
pp. 310-314
Author(s):  
Satya Preethi ◽  
Beeraka Chandra Sekhar ◽  
Pandiyan K R ◽  
Rajkumar R
Keyword(s):  
Glycemic Control ◽  
Lifestyle Modification ◽  
Patient Adherence ◽  
Microvascular Complications ◽  
Tertiary Care ◽  
Blood Glucose Control ◽  
Vascular Complications ◽  
Vascular Complication ◽  
Diabetic Patients ◽  
Diabetic Vascular Complications

Diabetes mellitus (DM) is a common metabolic disorder. It is associated with complications which will affect the quality of life. Failure to control elevated blood sugar or inadequate treatment of diabetes could cause many complications.  A prospective observational study is used to assess the prevalence of diabetic vascular complications in 105 types of II diabetic patients. A date was collected regarding patient's demographic and clinical characteristics. Based on our study criteria, males were more when compared to females in getting vascular complications & also. Complications were more prominent in the age group of 50-65years. Of all microvascular complications, Nephropathy was major, whereas, in macro-vascular complications, CAD was prominent. Poor glycemic control and a long length of ailment appear to be the most significant danger factors for these complexities. Doctors assume a significant function to endorse hostile to diabetic meds and Pharmacist plays a sharp task to assess the medicine design so as to accomplish fruitful treatment. The currently anti-diabetic drugs are effective, but a lot of factors such as patient adherence, education related to diabetes, lifestyle modification, cost and type of medication have an association with glycemic control. The commonly prescribed anti-diabetic drug was Insulin. Metformin was the most preferred drug both as monotherapy and combination therapy.  Although polypharmacy was observed, drug utilization pattern can be rational owing to a higher prevalence of complications. Minimization of the occurrence of complications should be courage by early diagnosis, intensive blood glucose control and rational drug selections.

The Role of Protein Kinase C Activation in the Pathogenesis of Diabetic Vascular Complications

1999 ◽  
Vol 19 (2_suppl) ◽  
pp. 222-227 ◽  
Author(s):  
Joong Yeol Park ◽  
Sung-Woo Ha ◽  
George L. King
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
De Novo ◽  
Vascular Complications ◽  
Vascular Diseases ◽  
Diabetic Rats ◽  
Diabetic Patients ◽  
Diabetic Vascular Complications ◽  
Kinase C

Many vascular diseases in diabetes are known to be associated with the activation of the diacylglycerol (OAG)protein kinase C (PKC) pathway. The major source of OAG that is elevated in diabetes is de novo synthesis from glycolytic intermediates. Among the various PKC isoforms, the β-isoform has been shown to be persistently activated in diabetic animals. Multiple lines of evidence have shown that many vascular alterations in diabetes such as a decrease in the activity of Na+-K+ -adenosine triphosphatase (Na+-K+-ATPase), and increases in extracellular matrix, cytokines, permeability, contractility, and cell proliferation -are caused by activation of PKC. Inhibition of PKC by two different kinds of PKC inhibitors, LY333531, a selective PKC-β-isoform inhibitor, and d-α-tocopherol, were able to prevent or reverse the various vascular dysfunctions in diabetic rats. These results have also provided in vivo evidence that OAG-PKC activation could be responsible for the hyperglycemia-induced vascular dysfunctions in diabetes. Clinical studies are now being performed to clarify the pathogenic roles of the OAG-PKC pathway in developing vascular complications in diabetic patients.

scholarly journals Potential Effect of Polyphenolic-Rich Fractions of Corn Silk on Protecting Endothelial Cells against High Glucose Damage Using In Vitro and In Vivo Approaches

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3665
Author(s):  
Nurraihana Hamzah ◽  
Sabreena Safuan ◽  
Wan Rosli Wan Ishak
Keyword(s):  
Endothelial Cells ◽  
Protective Effect ◽  
High Glucose ◽  
Vascular Complications ◽  
Diabetic Rats ◽  
Diabetic Patients ◽  
Dependent Manner ◽  
Corn Silk

Endothelial cell dysfunction is considered to be one of the major causes of vascular complications in diabetes. Polyphenols are known as potent antioxidants that can contribute to the prevention of diabetes. Corn silk has been reported to contain polyphenols and has been used in folk medicine in China for the treatment of diabetes. The present study aims to investigate the potential protective role of the phenolic-rich fraction of corn silk (PRF) against injuries to vascular endothelial cells under high glucose conditions in vitro and in vivo. The protective effect of PRF from high glucose toxicity was investigated using human umbilical vein endothelial cells (HUVECs). The protective effect of PRF was subsequently evaluated by using in vivo methods in streptozotocin (STZ)-induced diabetic rats. Results showed that the PRF significantly reduced the cytotoxicity of glucose by restoring cell viability in a dose-dependent manner. PRF was also able to prevent the histological changes in the aorta of STZ-induced diabetic rats. Results suggested that PRF might have a beneficial effect on diabetic patients and may help to prevent the development and progression of diabetic complications such as diabetic nephropathy and atherosclerosis.

scholarly journals Metformin prevents methylglyoxal-induced apoptosis by suppressing oxidative stress in vitro and in vivo

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Gang Wang ◽  
Yanan Wang ◽  
Qinzhi Yang ◽  
Chunrong Xu ◽  
Youkun Zheng ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Apoptosis ◽  
Vascular Complications ◽  
Tunel Staining ◽  
Ros Generation ◽  
Dependent Manner ◽  
Diabetic Vascular Complications ◽  
Induced Apoptosis

AbstractMethylglyoxal (MGO) is an active metabolite of glucose and plays a prominent role in the pathogenesis of diabetic vascular complications, including endothelial cell apoptosis induced by oxidative stress. Metformin (MET), a widely prescribed antidiabetic agent, appears to reduce excessive reactive oxygen species (ROS) generation and limit cell apoptosis. However, the molecular mechanisms underlying this process are still not fully elucidated. We reported here that MET prevents MGO-induced apoptosis by suppressing oxidative stress in vitro and in vivo. Protein expression and protein phosphorylation were investigated using western blotting, ELISA, and immunohistochemical staining, respectively. Cell viability and apoptosis were assessed by the MTT assay, TUNEL staining, and Annexin V-FITC and propidium iodide double staining. ROS generation and mitochondrial membrane potential (MMP) were measured with fluorescent probes. Our results revealed that MET prevented MGO-induced HUVEC apoptosis, inhibited apoptosis-associated biochemical changes such as loss of MMP, the elevation of the Bax/Bcl-2 ratio, and activation of cleaved caspase-3, and attenuated MGO-induced mitochondrial morphological alterations in a dose-dependent manner. MET pretreatment also significantly suppressed MGO-stimulated ROS production, increased signaling through the ROS-mediated PI3K/Akt and Nrf2/HO-1 pathways, and markedly elevated the levels of its downstream antioxidants. Finally, similar results were obtained in vivo, and we demonstrated that MET prevented MGO-induced oxidative damage, apoptosis, and inflammation. As expected, MET reversed MGO-induced downregulation of Nrf2 and p-Akt. In addition, a PI3K inhibitor (LY-294002) and a Nrf2 inhibitor (ML385) observably attenuated the protective effects of MET on MGO-induced apoptosis and ROS generation by inhibiting the Nrf2/HO-1 pathways, while a ROS scavenger (NAC) and a permeability transition pores inhibitor (CsA) completely reversed these effects. Collectively, these findings broaden our understanding of the mechanism by which MET regulates apoptosis induced by MGO under oxidative stress conditions, with important implications regarding the potential application of MET for the treatment of diabetic vascular complications.

Reliability of a Single β-Thromboglobulin Measurement in a Diabetic Population : Importance of PGE1 in Anticoagulant Mixture

1987 ◽  
Vol 57 (02) ◽  
pp. 201-204 ◽  
Author(s):  
P Y Scarabin ◽  
L Strain ◽  
C A Ludlam ◽  
J Jones ◽  
E M Kohner
Keyword(s):  
In Vitro Release ◽  
Mean Value ◽  
Reliable Estimate ◽  
Diabetic Patients ◽  
Single Measurement ◽  
Diabetic Population ◽  
The Difference ◽  
Vitro Release

SummaryDuring the collection of samples for plasma β-thromboglobulin (β-TG) determination, it is well established that artificially high values can be observed due to in-vitro release. To estimate the reliability of a single β-TG measurement, blood samples were collected simultaneously from both arms on two separate occasions in 56 diabetic patients selected for a clinical trial. From each arm, blood was taken into two tubes containing an anticoagulant mixture with (tube A) and without (tube B) PGE!. The overall mean value of B-TG in tube B was 1.14 times higher than in tube A (p <0.01). The markedly large between-arms variation accounted for the most part of within-subject variation in both tubes and was significantly greater in tube B than in tube A. Based on the difference between B-TG values from both arms, the number of subjects with artifically high B-TG values was significantly higher in tube B than in tube A on each occasion (overall rate: 28% and 14% respectively). Estimate of between-occasions variation showed that B-TG levels were relatively stable for each subject between two occasions in each tube. It is concluded that the use of PGEi decreases falsely high B-TG levels, but a single measurement of B-TG does not provide a reliable estimate of the true B-TG value in vivo.

Aspiration Revisited: Prospective Evaluation of a Physiologically Pressurized Model With Animal Correlation and Broader Applicability to Filler Complications

2021 ◽  
Author(s):  
Hyoung-Jin Moon ◽  
Won Lee ◽  
Ji-Soo Kim ◽  
Eun-Jung Yang ◽  
Hema Sundaram
Keyword(s):  
Normal Saline ◽  
False Negative ◽  
Vascular Complications ◽  
Filler Injection ◽  
Negative Results ◽  
Needle Position ◽  
False Negative Results ◽  
In Vivo Testing

Abstract Background Aspiration testing before filler injection is controversial. Some believe that aspiration can help prevent inadvertent intravascular injection, while others cite false-negative results and question its value given that the needle position always changes somewhat during injection procedures. Objectives To test the relation of false-negative results to the viscosity of the material within the needle lumen and determine whether a less viscous material within the needle lumen could decrease the incidence of false-negative results. Methods In vitro aspiration tests were performed using 30-G and 27-G needle gauges, two cross-linked hyaluronic acid fillers, normal saline bags pressurized at 140 and 10 mmHg to mimic human arterial and venous pressures, and three needle lumen conditions (normal saline, air, and filler). Testing was repeated three times under each study condition (72 tests in total). For in vivo correlation, aspiration tests were performed on femoral arteries and central auricular veins in three rabbits (4–5 aspirations per site, 48 tests in total). Results In vitro and in vivo testing using 30-G needles containing filler both showed false-negative results on aspiration testing. In vitro and in vivo testing using needles containing saline or air showed positive findings. Conclusions False-negative results from aspiration testing may be reduced by pre-filling the needle lumen with saline rather than a filler. The pressurized system may help overcome challenges of animal models with intravascular pressures significantly different from those of humans. The adaptability of this system to mimic various vessel pressures may facilitate physiologically relevant studies of vascular complications.

scholarly journals A small molecule HIF-1α stabilizer that accelerates diabetic wound healing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guodong Li ◽  
Chung-Nga Ko ◽  
Dan Li ◽  
Chao Yang ◽  
Wanhe Wang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Small Molecule ◽  
Hypoxia Inducible Factor ◽  
Diabetic Patients ◽  
Diabetic Mice ◽  
Impaired Wound Healing ◽  
Von Hippel Lindau ◽  
Design And Synthesis

AbstractImpaired wound healing and ulcer complications are a leading cause of death in diabetic patients. In this study, we report the design and synthesis of a cyclometalated iridium(III) metal complex 1a as a stabilizer of hypoxia-inducible factor-1α (HIF-1α). In vitro biophysical and cellular analyses demonstrate that this compound binds to Von Hippel-Lindau (VHL) and inhibits the VHL–HIF-1α interaction. Furthermore, the compound accumulates HIF-1α levels in cellulo and activates HIF-1α mediated gene expression, including VEGF, GLUT1, and EPO. In in vivo mouse models, the compound significantly accelerates wound closure in both normal and diabetic mice, with a greater effect being observed in the diabetic group. We also demonstrate that HIF-1α driven genes related to wound healing (i.e. HSP-90, VEGFR-1, SDF-1, SCF, and Tie-2) are increased in the wound tissue of 1a-treated diabetic mice (including, db/db, HFD/STZ and STZ models). Our study demonstrates a small molecule stabilizer of HIF-1α as a promising therapeutic agent for wound healing, and, more importantly, validates the feasibility of treating diabetic wounds by blocking the VHL and HIF-1α interaction.

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