Alexander Widiapradja

West Virginia University | WVU · Department of Physiology & Pharmacology

In addition to traditional neurotransmitters of the sympathetic and parasympathetic nervous systems, the heart also contains numerous neuropeptides. These neuropeptides not only modulate the effects of neurotransmitters, but also have independent effects on cardiac function. While in most cases the physiological actions of these neuropeptides are w...

Background The brain endothelium is a key component of the blood brain barrier which is compromised following ischemia, allowing infiltration of damaging immune cells and other inflammatory molecules into the brain. Intravenous immunoglobulin (IVIg) is known to reduce infarct size in a mouse model of experimental stroke. Findings Flow cytometry an...

J. Neurochem. (2012) 122, 321–332. Intravenous immunoglobulin (IVIg) preparations obtained by fractionating blood plasma, are increasingly being used increasingly as an effective therapeutic agent in treatment of several inflammatory diseases. Its use as a potential therapeutic agent for treatment of stroke and Alzheimer’s disease has been proposed...

The complement peptide C3a is a key component of the innate immune system and a major fragment produced following complement activation. We used a murine model of melanoma (B16-F0) to identify a hitherto unknown role for C3a-C3aR signaling in promoting tumor growth. The results show that the development and growth of B16-F0 melanomas is retarded in...

Substance P (SP) is released from sensory nerves in arteries and heart. It activates neurokinin-1 receptors (NK1R) causing vasodilation, immune modulation, and adverse cardiac remodeling. The hypothesis was tested that SP and SP metabolites activate different second messenger signaling pathways. Macrophages, endothelial cells and fibroblasts metabo...

Background: Type 2 diabetes mellitus (T2DM)-associated cardiac fibrosis contributes to heart failure. We previously showed that diabetic mice with cardiomyopathy, including cardiac fibrosis, exhibit low levels of the neuropeptide substance P; exogenous replacement of substance P reversed cardiac fibrosis, independent of body weight, blood glucose...

Context. Foxe1 is a key thyroid developmental transcription factor. Germline deletion results in athyreosis and congenital hypothyroidism. Some data suggest an ongoing role for maintaining thyroid differentiation. Objective. We created a mouse model to directly examine the role of Foxe1 in the adult thyroid. Methods. A model of tamoxifen-inducibl...

Introduction: Type 2 diabetes mellitus (T2DM)-associated cardiac fibrosis contributes to heart failure, especially in women. We have data showing that diabetic mice with cardiomyopathy, including cardiac fibrosis, exhibit low levels of the neuropeptide substance P (SP); and SP replacement reverses cardiac fibrosis, independent of body weight and bl...

Reduced levels of the sensory nerve neuropeptide substance P (SP) have been reported in the diabetic rat heart, the consequence being a loss of cardioprotection in response to ischemic post-conditioning. We considered whether this loss of SP also predisposes the heart to non-ischemic diabetic cardiomyopathy in the form of fibrosis and hypertrophy....

Histamine is a basic amine stored in mast cells, with its release capable of activating one of four histamine receptors. The histamine 3 receptor (H3R) is known to be cardioprotective during acute ischemia by acting to limit norepinephrine release. However, a recent study reported that myofibroblasts isolated from the infarct zone of rat hearts res...

Diabetic cardiomyopathy involves remodeling of the heart in response to diabetes that includes microvascular damage, cardiomyocyte hypertrophy, and cardiac fibrosis. Cardiac fibrosis is a major contributor to diastolic dysfunction that can ultimately result in heart failure with preserved ejection fraction. Cardiac fibroblasts are the final effecto...

Introduction Adverse cardiac remodelling is a response of the heart to various stimuli and if left untreated can progress to heart failure. Nr4a1, an orphan nuclear receptor, has been shown to have conflicting contributions to adverse cardiac remodelling in several aetiologies, making its role in cardiac remodelling unclear. Purpose To investigate...

Cardiac fibrosis is an underlying cause of diastolic dysfunction, contributing to heart failure. Substance P (SP) activation of the neurokinin-1 receptor (NK-1R) contributes to cardiac fibrosis in hypertension. However, based on in vitro experiments, this does not appear to be via direct activation of cardiac fibroblasts. While numerous cells could...

Substance P (SP) and mast cells (MCs) both play a detrimental role in initiating myocardial remodeling, including fibrosis, in response to pressure overload. However, it is not known whether MC activation is an underlying mechanism mediating the effects of SP in this setting. We sought to determine whether SP and its cognate receptor, the neurokini...

Background: Cancer patients receiving anthracycline-based chemotherapy (Anth-bC) may experience early cardiac fibrosis, which could be an important contributing mechanism to the development of impaired left ventricular (LV) function. Substance P, a neuropeptide that predominantly acts via the neurokinin 1 receptor (NK-1R), contributes to adverse m...

Myocardial remodelling such as fibrosis is a major contributor to heart failure with preserved ejection fraction. We sought to determine the relationship between substance P (SP), a sensory neuropeptide, and this adverse remodelling. Using the angiotensin II mouse model of pressure overload we determined that Tac1 -/- mice that are genetically defi...

Historically, increased numbers of mast cells have been associated with fibrosis in numerous cardiac pathologies, implicating mast cells in the development of cardiac fibrosis. Subsequently, several approaches have been utilised to demonstrate a causal role for mast cells in animal models of cardiac fibrosis including mast cell stabilising compound...

Recent findings have revealed a novel inflammatory mechanism that contributes to tissue injury in cerebral ischemia mediated by multi-protein complexes termed inflammasomes. Intermittent fasting (IF) can decrease the levels of pro-inflammatory cytokines in the periphery and brain. Here we investigated the impact of IF (16hours of food deprivation d...

Multi-protein complexes called inflammasomes have recently been identified and shown to contribute to cell death in tissue injury. Intravenous immunoglobulin (IVIg) is an FDA-approved therapeutic modality used for various inflammatory diseases. The objective of this study is to investigate dynamic responses of the NLRP1 and NLRP3 inflammasomes in s...

Ephrin (Eph) signaling within the central nervous system is known to modulate axon guidance, synaptic plasticity, and to promote long-term potentiation. We investigated the potential involvement of EphA2 receptors in ischemic stroke-induced brain inflammation in a mouse model of focal stroke. Cerebral ischemia was induced in male C57Bl6/J wild-type...