Track topics on Twitter Track topics that are important to you
Type 1 diabetic Akita mice develop severe cardiac parasympathetic dysfunction that we have previously demonstrated is due at least in part to an abnormality in the response of the end organ to parasympathetic stimulation. Specifically, we had shown that hypoinsulinemia in the diabetic heart results in attenuation of the G-protein coupled inward rectifying K channel (GIRK) which mediates the negative chronotropic response to parasympathetic stimulation due at least in part to decreased expression of the GIRK1 and GIRK4 subunits of the channel. We further demonstrated that the expression of GIRK1 and GIRK4 is under the control of the Sterol Regulatory element Binding Protein (SREBP-1), which is also decreased in response to hypoinsulinemia. Finally, given that hyperactivity of Glycogen Synthase Kinase (GSK)3β, had been demonstrated in the diabetic heart, we demonstrated that treatment of Akita mice with Li+, an inhibitor of GSK3β, increased parasympathetic responsiveness and SREBP-1 levels consistent with the conclusion that GSK3β might regulate IKACh via an effect on SREBP-1. However, inhibitor studies were complicated by lack of specificity for GSK3β. Here we generated an Akita mouse with cardiac specific inducible knockout of GSK3β. Using this mouse, we demonstrate that attenuation of GSK3β expression is associated with an increase in parasympathetic responsiveness measured as an increase in the heart rate response to atropine from 17.3 ± 3.5% (n = 8) prior to 41.2 ± 5.4% (n = 8, P = 0.017), an increase in the duration of carbamylcholine mediated bradycardia from 8.43 ± 1.60 min (n = 7) to 12.71 ± 2.26 min (n = 7, P = 0.028) and an increase in HRV as measured by an increase in the high frequency fraction from 40.78 ± 3.86% to 65.04 ± 5.64 (n = 10, P = 0.005). Furthermore, patch clamp measurements demonstrated a 3-fold increase in acetylcholine stimulated peak IKACh in atrial myocytes from GSK3β deficiency mice compared with control. Finally, western blot analysis of atrial extracts from knockout mice demonstrated increased levels of SREBP-1, GIRK1 and GIRK4 compared with control. Taken together with our prior observations, these data establish a role of increased GSK3β activity in the pathogenesis of parasympathetic dysfunction in type 1 diabetes via the regulation of IKACh and GIRK1/4 expression.
This article was published in the following journal.
Name: PloS one
Sprouty1 (Spry1) is a negative modulator of receptor tyrosine kinase signaling, but its role in cardiomyocyte survival has not been elucidated. The aim of this study was to investigate the potential r...
Nicotinamide phosphoribosyl transferase (NAMPT) is a cytokine which is secreted by adipose tissue and involved in the process of immunoreactions, inflammation, and lipid metabolism through the endocri...
Neurofibrillary tangles aggregated from hyperphosphorylated tau protein are the main pathological feature of Alzheimer's disease (AD). Complement C3 (or C3a) is the core component of the complement sy...
In this study, we investigated the pathophysiological impact of Rho-associated coiled-coil-containing protein kinase (ROCK)1 and ROCK2 double deletion vs. single deletion on cardiac remodeling. Utiliz...
Rutaecarpine attenuates hypertensive cardiac hypertrophy in the rats with abdominal artery constriction (AAC); however, its mechanism of action remains largely unknown. Our previous study indicated th...
The project is designed to generate critical information to design and justify a robust trial on lithium prevention of the onset of Alzheimer's disease (AD). Lithium exerts and inhibitory ...
Assessment of GSK-3beta contents in leukocytes in on-pump cardiosurgical patients receiving either volatile or intravenous anesthesia
The purpose of this study is to evaluate if 4 escalating doses during 20 weeks of NP031112 are safe and tolerated in patients with Alzheimer´s disease.
A growing body of pre-clinical evidence suggests that glycogen synthase kinase 3β (GSKβ) is implicated in the development and progression of acute kidney injury (AKI). Lithium is a natur...
Glycogen, is the storage form of glucose. It is usually formed from sugar and stored in the liver. When tissues, such as muscle, need glucose for fuel the stored glycogen is converted in...
A glycogen synthase kinase that was originally described as a key enzyme involved in glycogen metabolism. It regulates a diverse array of functions such as CELL DIVISION, microtubule function and APOPTOSIS.
A glycogen synthase kinase-3 type enzyme that functions in ENERGY METABOLISM; EMBRYONIC DEVELOPMENT; and NEUROGENESIS. It is also involved in PROTEIN BIOSYNTHESIS and regulates cell growth and proliferation as a component of the WNT SIGNALING PATHWAY and other signaling pathways. Certain polymorphisms in the GSK3B gene have been associated with PARKINSON DISEASE; ALZHEIMER DISEASE; and BIPOLAR DISORDER.
A class of protein-serine-threonine kinases that was originally found as one of the three types of kinases that phosphorylate GLYCOGEN SYNTHASE. Glycogen synthase kinases along with CA(2+)-CALMODULIN DEPENDENT PROTEIN KINASES and CYCLIC AMP-DEPENDENT PROTEIN KINASES regulate glycogen synthase activity.
An enzyme that catalyzes the conversion of phosphorylated, inactive glycogen synthase D to active dephosphoglycogen synthase I. EC 184.108.40.206.
A scaffolding protein that is a critical component of the axin signaling complex which binds to ADENOMATOUS POLYPOSIS COLI PROTEIN; GLYCOGEN SYNTHASE KINASE 3; and CASEIN KINASE I.
Diabetes is a lifelong condition that causes a person's blood sugar level to become too high. The two main types of diabetes are: type 1 diabetes type 2 diabetes In the UK, diabetes affects approximately 2.9 million people. There are a...
Cardiovascular disease (CVD)
Acute Coronary Syndromes (ACS) Blood Cardiovascular Dialysis Hypertension Stent Stroke Vascular Cardiovascular disease (CVD) includes all the diseases of the heart and circulation including coronary heart disease (angina...