Anti-proliferative activity of oral anti-hyperglycemic agents on human vascular smooth muscle cells: thiazolidinediones (glitazones) have enhanced activity under high glucose conditions

Background: Inhibition of vascular smooth muscle cell (vSMC) proliferation by oral anti-hyperglycemic agents may have a role to play in the amelioration of vascular disease in diabetes. Thiazolidinediones (TZDs) inhibit vSMC proliferation but it has been reported that they anomalously stimulate [3H]-thymidine incorporation. We investigated three TZDs, two biguanides and two sulfonylureas for their ability of inhibit vSMC proliferation. People with diabetes obviously have fluctuating blood glucose levels thus we determined the effect of media glucose concentration on the inhibitory activity of TZDs in a vSMC preparation that grew considerably more rapidly under high glucose conditions. We further explored the mechanisms by which TZDs increase [3H]-thymidine incorporation. Methods: VSMC proliferation was investigated by [3H]- thymidine incorporation into DNA and cell counting. Activation and inhibition of thymidine kinase utilized short term [3H]- thymidine uptake. Cell cycle events were analyzed by FACS

Potgrondproef met 12-10-18 bij tomaat

<p><b>Copyright information:</b></p><p>Taken from "Anti-proliferative activity of oral anti-hyperglycemic agents on human vascular smooth muscle cells: thiazolidinediones (glitazones) have enhanced activity under high glucose conditions"</p><p>http://www.cardiab.com/content/6/1/33</p><p>Cardiovascular Diabetology 2007;6():33-33.</p><p>Published online 28 Oct 2007</p><p>PMCID:PMC2211460.</p><p></p>e mean ± SEM, *P < 0.05 PDGF. B. Human vSMCs were treated with metformin (10–300 μM) and phenformin (10–300 μM) in the presence of 5% serum for 3 days and then counted on a Coulter counter. Data represent the mean ± SEM from 2 experiments in triplicate **P < 0.01, ***P < 0.001 the 5% FBS

Anti-proliferative activity of oral anti-hyperglycemic agents on human vascular smooth muscle cells: thiazolidinediones (glitazones) have enhanced activity under high glucose conditions-2

<p><b>Copyright information:</b></p><p>Taken from "Anti-proliferative activity of oral anti-hyperglycemic agents on human vascular smooth muscle cells: thiazolidinediones (glitazones) have enhanced activity under high glucose conditions"</p><p>http://www.cardiab.com/content/6/1/33</p><p>Cardiovascular Diabetology 2007;6():33-33.</p><p>Published online 28 Oct 2007</p><p>PMCID:PMC2211460.</p><p></p>ine over 4 min was assessed. The results show the effects of two identical experiments in duplicate. B. Shows concomitant data for routine assay of [H]-thymidine into DNA (see methods for details)

Anti-proliferative activity of oral anti-hyperglycemic agents on human vascular smooth muscle cells: thiazolidinediones (glitazones) have enhanced activity under high glucose conditions-4

<p><b>Copyright information:</b></p><p>Taken from "Anti-proliferative activity of oral anti-hyperglycemic agents on human vascular smooth muscle cells: thiazolidinediones (glitazones) have enhanced activity under high glucose conditions"</p><p>http://www.cardiab.com/content/6/1/33</p><p>Cardiovascular Diabetology 2007;6():33-33.</p><p>Published online 28 Oct 2007</p><p>PMCID:PMC2211460.</p><p></p>e mean ± SEM, *P < 0.05 PDGF. B. Human vSMCs were treated with metformin (10–300 μM) and phenformin (10–300 μM) in the presence of 5% serum for 3 days and then counted on a Coulter counter. Data represent the mean ± SEM from 2 experiments in triplicate **P < 0.01, ***P < 0.001 the 5% FBS

Anti-proliferative activity of oral anti-hyperglycemic agents on human vascular smooth muscle cells: thiazolidinediones (glitazones) have enhanced activity under high glucose conditions-0

<p><b>Copyright information:</b></p><p>Taken from "Anti-proliferative activity of oral anti-hyperglycemic agents on human vascular smooth muscle cells: thiazolidinediones (glitazones) have enhanced activity under high glucose conditions"</p><p>http://www.cardiab.com/content/6/1/33</p><p>Cardiovascular Diabetology 2007;6():33-33.</p><p>Published online 28 Oct 2007</p><p>PMCID:PMC2211460.</p><p></p>anels D, E and F. Data represent the mean ± SEM from 3 experiments in triplicate *P < 0.05, ***P < 0.00

Long-Term Overexpression of Hsp70 Does Not Protect against Cardiac Dysfunction and Adverse Remodeling in a MURC Transgenic Mouse Model with Chronic Heart Failure and Atrial Fibrillation

<div><p>Previous animal studies had shown that increasing heat shock protein 70 (Hsp70) using a transgenic, gene therapy or pharmacological approach provided cardiac protection in models of acute cardiac stress. Furthermore, clinical studies had reported associations between Hsp70 levels and protection against atrial fibrillation (AF). AF is the most common cardiac arrhythmia presenting in cardiology clinics and is associated with increased rates of heart failure and stroke. Improved therapies for AF and heart failure are urgently required. Despite promising observations in animal studies which targeted Hsp70, we recently reported that increasing Hsp70 was unable to attenuate cardiac dysfunction and pathology in a mouse model which develops heart failure and intermittent AF. Given our somewhat unexpected finding and the extensive literature suggesting Hsp70 provides cardiac protection, it was considered important to assess whether Hsp70 could provide protection in another mouse model of heart failure and AF. The aim of the current study was to determine whether increasing Hsp70 could attenuate adverse cardiac remodeling, cardiac dysfunction and episodes of arrhythmia in a mouse model of heart failure and AF due to overexpression of Muscle-Restricted Coiled-Coil (MURC). Cardiac function and pathology were assessed in mice at approximately 12 months of age. We report here, that chronic overexpression of Hsp70 was unable to provide protection against cardiac dysfunction, conduction abnormalities, fibrosis or characteristic molecular markers of the failing heart. In summary, elevated Hsp70 may provide protection in acute cardiac stress settings, but appears insufficient to protect the heart under chronic cardiac disease conditions.</p></div

Transgenic overexpression of HSP70 did not attenuate cardiac dysfunction and electrophysiology abnormalities.

<p><b>(A)</b> Quantification of LVEDD, LVESD and FS in 12 month old Ntg, MURC and MURC-Hsp70 Tg mice. N = 3–5 per group. *P<0.05 vs. Ntg, **P<0.0005 vs. Ntg, †P<0.05. Lower right: Representative M-mode echocardiograms in 12 month old Ntg, MURC and MURC-Hsp70 Tg mice. <b>(B)</b> Representative ECG traces in 12 month old Ntg, MURC and MURC-Hsp70 Tg mice. Arrows highlight clear P-waves. <b>(C)</b> Quantification of R amplitude and PR interval in Ntg, MURC and MURC-Hsp70 Tg mice. N = 3–5 per group. *P<0.05 vs. Ntg, †P≤0.05. <b>(D)</b> Representative heart rate (HR) variability traces and quantification of time in arrhythmia in 12 month old Ntg, MURC and MURC-Hsp70 Tg mice. N = 3–5 per group. *P<0.05 vs. Ntg (One Way ANOVA with Fisher’s posthoc test), †P<0.05, P = 0.06 (Mann-Whitney nonparametric t-test).</p

Cardiac morphology in MURC and MURC-Hsp70 Tg mouse models.

<p><b>(A)</b> Transverse sections of hearts highlighting dilated chambers in MURC-Hsp70 Tg mice compared to MURC Tg mice. LV = left ventricle, RV = right ventricle. Scale bar = 1 mm. <b>(B)</b> Graph of atria weight/tibia length (AW/TL). N = 3–5 per group. *P<0.05 vs. Ntg, †P<0.05 vs. MURC. The dotted line reflects normal AW/TL for Ntg mice at about 3–4 months of age. <b>(C)</b> qPCR analysis of Collagen 3 <i>(Col3a1)</i> relative to <i>Hprt1</i> in atria. N = 3–5 per group. *P≤0.05 vs. Ntg (One way ANOVA with Fisher’s posthoc test), ^P<0.05 vs. Ntg (unpaired t-test).</p