Pal Pacher

Pal Pacher
National Institutes of Health | NIH · National Institute of Alcohol Abuse and Alcoholism (NIAAA)

MD PhD FAPS FAHA FACC

About

464
Publications
82,338
Reads
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44,129
Citations
Additional affiliations
January 2015 - present
National Institutes of Health
Position
  • Head, Laboratory of Cardiovascular Physiology and Tissue Injury, Tenured Senior Investigator
July 2012 - January 2015
National Institutes of Health
Position
  • Chief, Section of Oxidative Stress and Tissue Injury, LPS; Tenured Senior Investigator

Publications

Publications (464)
Article
Dysregulation of the endogenous lipid mediators endocannabinoids and their G-protein-coupled cannabinoid receptors 1 and 2 (CB1R and CB2R) has been implicated in a variety of cardiovascular pathologies. Activation of CB1R facilitates the development of cardiometabolic disease, whereas activation of CB2R (expressed primarily in immune cells) exerts...
Article
Background and rationale: Hepatic cardiomyopathy, a special type of heart failure develops in up to 50% of patients with cirrhosis and is a major determinant of survival. However, there is no reliable model of hepatic cardiomyopathy in mice. Herein we aimed to characterize the detailed hemodynamics of mice with bile-duct ligation (BDL)-induced liv...
Article
Research in the cannabinoid field, namely on phytocannabinoids, the endogenous cannabinoids anandamide and 2-arachidonoyl glycerol and their metabolizing and synthetic enzymes, the cannabinoid receptors, and anandamide-like cannabinoid compounds, has expanded tremendously over the last few years. Numerous endocannabinoid-like compounds have been di...
Article
The liver is a crucial metabolic organ that has a key role in maintaining immune and endocrine homeostasis. Accumulating evidence suggests that chronic liver disease might promote the development of various cardiac disorders (such as arrhythmias and cardiomyopathy) and circulatory complications (including systemic, splanchnic and pulmonary complica...
Article
Full-text available
N-acylethanolamines (NAEs), which include the endocannabinoid anandamide, represent an important family of signaling lipids in the brain. The lack of chemical probes that modulate NAE biosynthesis in living systems hamper the understanding of the biological role of these lipids. Using a high-throughput screen, chemical proteomics and targeted lipid...
Preprint
Extracellular adenosine is a biologically active signaling molecule that accumulates at sites of metabolic stress in sepsis. Extracellular adenosine has potent immunosuppressive effects by binding to and activating G protein-coupled A 2A adenosine receptors (A 2A ARs) on the surface of neutrophils. A 2A AR signaling reproduces many of the phenotypi...
Article
Diabetes mellitus promotes accelerated cardiovascular aging and inflammation, which in turn facilitate the development of cardiomyopathy/heart failure. High glucose-induced oxidative/nitrative stress, activation of various pro-inflammatory, and cell death pathways are critical in the initiation and progression of the changes culminating in diabetic...
Article
Full-text available
Despite its essential role in the (patho)physiology of several diseases, CB2R tissue expression profiles and signaling mechanisms are not yet fully understood. We report the development of a highly potent, fluorescent CB2R agonist probe employing structure-based reverse design. It commences with a highly potent, preclinically validated ligand, whic...
Article
Full-text available
Sepsis is life-threatening organ dysfunction caused by a dysregulated inflammatory and immune response to infection. Sepsis involves the combination of exaggerated inflammation and immune suppression. During systemic infection and sepsis, the liver works as a lymphoid organ with key functions in regulating the immune response. Extracellular nucleot...
Article
Inosine monophosphate (IMP) is the intracellular precursor for both adenosine monophosphate and guanosine monophosphate and thus plays a central role in intracellular purine metabolism. IMP can also serve as an extracellular signaling molecule, and can regulate diverse processes such as taste sensation, neutrophil function, and ischemia‐reperfusion...
Article
Resolution of inflammation requires proresolving molecular pathways triggered as part of the host response during the inflammatory phase. Adenosine and its receptors, which are collectively called the adenosine system, shape inflammatory cell activity during the active phase of inflammation, leading these immune cells toward a functional repolariza...
Article
The pathogenesis of pancreatitis has been linked to disruption of organelle homeostasis including macroautophagy/autophagy dysfunction and endoplasmic reticulum (ER) stress. However, the direct impact of aberrant organelle function on pancreatitis initiation and progression is largely unknown. Recently an ER membrane protein, VMP1 (vacuole membrane...
Article
PARPs and tankyrases (TNKS) represent a family of 17 proteins. PARPs and tankyrases were originally identified as DNA repair factors, nevertheless, recent advances have shed light on their role in lipid metabolism. To date, PARP1, PARP2, PARP3, tankyrases, PARP9, PARP10, PARP14 were reported to have multi-pronged connections to lipid metabolism. Th...
Article
Nucleoside triphosphate diphosphohydrolases (NTPDases) are a family of enzymes that hydrolyze nucleotides such as ATP, UTP, ADP, and UDP to monophosphates derivates such as AMP and UMP. The NTPDase family consists of eight enzymes, of which NTPDases 1, 2, 3, and 8 are expressed on cell membranes thereby hydrolyzing extracellular nucleotides. Cell m...
Article
Full-text available
Alcohol use disorder (AUD) is a chronic relapsing disorder characterized by an impaired ability to control or stop alcohol intake and is associated with organ damage including alcohol-associated liver disease (ALD) and progressive neurodegeneration. The etiology of AUD is complex, but organ injury due to chronic alcohol use can be partially attribu...
Article
Cholangiopathies caused by biliary epithelial cell (BEC) injury represent a leading cause of liver failure. No effective pharmacologic therapies exist, and the underlying mechanisms remain obscure. We aimed to explore the mechanisms of bile duct repair after targeted BEC injury. Injection of intermedilysin into BEC-specific human CD59 (hCD59) trans...
Article
P2Y receptors are G protein-coupled receptors whose physiological agonists are the nucleotides ATP, ADP, UTP, UDP and UDP-glucose. Eight P2Y receptors have been cloned in humans: P2Y1R, P2Y2R, P2Y4R, P2Y6R, P2Y11R, P2Y12R, P2Y13R and P2Y14R. P2Y receptors are expressed in lymphoid tissues such as thymus, spleen and bone marrow where they are expres...
Article
Macrophages are cells of the innate immune system that play myriad roles in the body. Macrophages are known to reside in endocrine glands, and a body of evidence now suggests that these cells interact closely with endocrine cells. Immune–endocrine interactions are important in the development of endocrine glands and their functioning during physiol...
Article
Neutrophil infiltration around lipotoxic hepatocytes is a hallmark of nonalcoholic steatohepatitis (NASH); however, how these two types of cells communicate remain obscure. We have previously demonstrated that neutrophil-specific microRNA-223 (miR-223) is elevated in hepatocytes to limit NASH progression in obese mice. Here we demonstrated that thi...
Article
Pharmacological modulation of cannabinoid type 2 receptor (CB2R) holds promise for the treatment of numerous con-ditions, including inflammatory diseases, autoimmune disorders, pain, and cancer. Despite the significance of this re-ceptor, researchers lack reliable tools to address questions concerning the expression and complex mechanism of CB2R si...
Article
Despite the broad implications of the cannabinoid type 2 receptor (CB2) in neuroinflammatory processes, a suitable CB2-targeted probe is currently lacking in clinical routine. In this work, we synthesized 15 fluorinated pyridine derivatives and tested their binding affinities toward CB2 and CB1. With a sub-nanomolar affinity (Ki for CB2) of 0.8 nM...
Preprint
Pharmacological modulation of cannabinoid type 2 receptor (CB<sub>2</sub>R) holds promise for the treatment of numerous conditions, including inflammatory diseases, autoimmune disorders, pain, and cancer. Despite the significance of this receptor, researchers lack reliable tools to address questions concerning the expression and complex mechanism o...
Article
Study rationale: Hepatorenal syndrome (HRS) is a life-threatening complication of end-stage liver disease characterized by the rapid decline of kidney function. Herein, we explored the therapeutic potential of targeting the cannabinoid 2 receptor (CB2-R) utilizing a commonly used mouse model of liver fibrosis and hepatorenal syndrome (HRS), induce...
Article
Full-text available
Background & aims: Alcohol abuse is the major cause of experimental and human pancreatitis but the molecular mechanisms remain largely unknown. We investigated the role of transcription factor EB (TFEB), a master regulator of lysosomal biogenesis, in the pathogenesis of alcoholic pancreatitis METHODS: Using a chronic plus acute alcohol binge (refe...
Article
Aim: Acute myocardial infarction and subsequent post-infarction heart failure are among the leading causes of mortality worldwide. The endocannabinoid system has emerged as an important modulator of cardiovascular disease, however the role of endocannabinoid metabolic enzymes in heart failure is still elusive. Herein, we investigated the endocanna...
Preprint
Pharmacological modulation of cannabinoid type 2 receptor (CB2R) holds promise for the treatment of numerous conditions including inflammatory diseases, autoimmune disorders, pain, and cancer. Despite its significance, researchers lack reliable tools to address questions concerning the complex mechanism of CB2R signaling and its downstream conseque...
Preprint
Cannabinoid type 2 receptor (CB<sub>2</sub>R) is a fundamental part of the endocannabinoid signaling system (eCB system), and is known to play an important role in tissue injury, inflammation, cancer and pain. In stark contrast to its significance, the underlying signaling mechanisms and tissue expression profiles are poorly understood. Due to its...
Article
Full-text available
Alcoholic liver disease (ALD) causes significant morbidity and mortality, and pharmacological treatment options are limited. In this study, we evaluated the PCSK9 inhibitor alirocumab, a monoclonal antibody that robustly reduces low-density lipoprotein cholesterol (LDL-C), for the treatment of ALD using a rat model of chronic alcohol exposure. Alir...
Article
Background & aims: Acute-on-chronic liver failure (ACLF) is a clinical syndrome defined by liver failure on preexisting chronic liver disease and is often associated with bacterial infection with high short-term mortality. Experimental models that fully reproduce ACLF and effective pharmacological therapies are lacking. Methods: To mimic ACLF co...
Article
Full-text available
Excessive binge alcohol drinking may adversely affect cardiovascular function. In this study we characterize the detailed hemodynamic effects of an acute alcohol binge in mice using multiple approaches and investigate the role of the endocannabinoid–cannabinoid 1 receptor (CB1-R) signaling in these effects. Acute alcohol binge was associated with e...
Article
Sepsis is life-threatening systemic organ dysfunction caused by a deregulated host response to an infectious insult. Currently, the treatment of sepsis is limited to the use of antibiotics, fluids, and cardiovascular/respiratory support. Despite these interventions, septic mortality remains high, with reduced life quality in survivors. For this rea...
Article
Immune-mediated inflammatory diseases (IMIDs) encompass a wide range of seemingly unrelated conditions, such as multiple sclerosis, rheumatoid arthritis, psoriasis, inflammatory bowel diseases, asthma, chronic obstructive pulmonary disease, and systemic lupus erythematosus. Despite differing etiologies, these diseases share common inflammatory path...
Article
Full-text available
Purpose of the Review Activation of myocardial cannabinoid type 1 receptors (CB1-R) and/or angiotensin II type 1 receptors (AT1-R) likely plays an important mechanistic role in determining the left-ventricular remodeling process in systolic heart failure. We provide an overview on novel radiotracer probes and positron emission tomography (PET)/comp...
Article
Impaired macroautophagy/autophagy has been implicated in experimental and human pancreatitis. However, the transcriptional control governing the autophagy-lysosomal process in pancreatitis is largely unknown. We investigated the role and mechanisms of TFEB (transcription factor EB), a master regulator of lysosomal biogenesis, in the pathogenesis of...
Article
Quorum sensing was first described as the communication process bacteria employ to coordinate changes in gene expression and therefore, their collective behavior in response to population density. Emerging new evidence suggests that quorum sensing can also contribute to the regulation of immune cell responses. Quorum sensing might be achieved by th...
Article
Full-text available
Objective Aldehyde dehydrogenase 2 (ALDH2), a key enzyme to detoxify acetaldehyde in the liver, exists in both active and inactive forms in humans. Individuals with inactive ALDH2 accumulate acetaldehyde after alcohol consumption. However, how acetaldehyde affects T-cell hepatitis remains unknown. Design Wild-type (WT) and Aldh2 knockout (Aldh2 -/...
Article
Full-text available
Quorum sensing is the regulation of gene expression programmes in response to changes in population density. It is probably best recognized as a mechanism through which bacterial communities can synchronize behaviours, such as biofilm formation and bioluminescence. This Comment article highlights the emerging evidence suggesting that quorum sensing...
Article
Full-text available
Unexpected cardiac adverse effects are the leading causes of discontinuation of clinical trials and withdrawal of drugs from the market. Since the original observations in the mid-90s, it has been well established that cardiovascular risk factors and comorbidities (such as ageing, hyperlipidaemia, and diabetes) and their medications (e.g. nitrate t...
Article
Full-text available
The macrophage is a major phagocytic cell type, and its impaired function is a primary cause of immune paralysis, organ injury, and death in sepsis. An incomplete understanding of the endogenous molecules that regulate macrophage bactericidal activity is a major barrier for developing effective therapies for sepsis. Using an in vitro killing assay,...
Article
Ageing is the main risk factor for the development of cardiovascular diseases. A central mechanism by which ageing promotes vascular pathologies is compromising endothelial health. The age-related attenuation of endothelium-dependent dilator responses (endothelial dysfunction) associated with impairment of angiogenic processes and the subsequent pa...
Article
Conclusions: We propose that hyperammonemia may contribute to impaired renal arginine metabolism, leading to decreased eNOS activity, impaired microcirculation, tubular cell death, tubulointerstitial nephritis and fibrosis. Genetic deletion of arginase-2 partially restores microcirculation and thereby alleviates tubular injury. We also demonstrate...
Article
Adenosine is increasingly recognized as a key mediator of the immune response. Signals delivered by extracellular adenosine are detected and transduced by G-protein-coupled cell-surface receptors, classified into four subtypes: A1, A2A, A2B and A3. These receptors, expressed virtually on all immune cells, modulate all aspects of immune/inflammatory...
Chapter
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Mitochondria-related cardiotoxicity results from the interference of drugs with processes of normal mitochondrial homeostasis. Mitochondria have a crucial role in myocardial tissue homeostasis, providing ATP for the contractile apparatus and critical enzymes in intermediate metabolism and maintaining ion homeostasis. Modifications of mitochondrial...
Article
Full-text available
Conclusion: the dysregulation of SIRT1-DEPTOR-mTORC1 signaling is a critical determinant of ALD pathology. Targeting SIRT1 and DEPTOR and selectively inhibiting mTORC1-S6K1 signaling may have therapeutic potential for treating ALD in humans. This article is protected by copyright. All rights reserved.
Article
Chemical tools and methods that report on G protein-coupled receptor (GPCR) expression levels and receptor occupancy by small molecules are highly desirable. We report the development of LEI121 as a photoreactive probe to study the type 2 cannabinoid receptor (CB2R), a promising GPCR to treat tissue injury and inflammatory diseases. LEI121 is the f...
Article
Objectives: The aim of this study was to evaluate the feasibility of targeted imaging of myocardial cannabinoid type 1 receptor (CB1-R) and its potential up-regulation in obese mice with translation to humans using [11C]-OMAR and positron emission tomography (PET)/computed tomography (CT). Background: Activation of myocardial CB1-R by endocannab...
Article
Sterile inflammation after tissue damage is a ubiquitous response, yet it has the highest amplitude in the liver. This has major clinical consequences, for alcoholic and non-alcoholic steatohepatitis (ASH and NASH) account for the majority of liver disease in industrialized countries and both lack therapy. Requirements for sustained sterile inflamm...
Article
Alcoholic liver disease (ALD) is characterized by lipid accumulation and liver injury. However, how chronic alcohol consumption causes hepatic lipid accumulation remains elusive. The present study demonstrates that activation of the mechanistic target of rapamycin complex 1 (mTORC1) plays a causal role in alcoholic steatosis, inflammation, and live...
Article
Full-text available
Backgrounds and Aims Hepatic infiltration of neutrophils is a hallmark of steatohepatitis; however, the role of neutrophils in the progression of steatohepatitis remains unknown. Methods A clinically relevant mouse model of steatohepatitis induced by high-fat diet (HFD)-plus-binge ethanol feeding was used. Liver fibrosis was examined. In vitro cel...
Article
Full-text available
Pepcan-12 (RVD-hemopressin; RVDPVNFKLLSH) is the major peptide of a family of endogenous peptide endocannabinoids (pepcans) shown to act as negative allosteric modulators (NAM) of cannabinoid CB1 receptors. Noradrenergic neurons have been identified to be a specific site of pepcan production. However, it remains unknown whether pepcans occur in the...
Article
Full-text available
Increased oxidative stress is a major contributor to the development and progression of heart failure, however, our knowledge on the role of the distinct NADPH oxidase (NOX) isoenzymes, especially on NOX4 is controversial. Therefore, we aimed to characterize NOX4 expression in human samples from healthy and failing hearts. Explanted human heart sam...
Data
Original Western blots for NOX4 (A), GAPDH (B), and total protein staining by Ponceau S stain (C) in left ventricular (LV), right ventricular (RV), and interventricular septal regions (IVS) of ischemic cardiomyopathy patients (ICM).
Data
Original Western blots for phosphorylated ERK1/2, total ERK1/2, GAPDH and total protein staining by Ponceau S stain in left ventricular (LV) samples of ischemic (ICM—A) or dilated cardiomyopathy patients (DCM—B), respectively. Data are mean ± S.E.M. n = 5/group. *p < 0.05.
Data
Original Western blots for NOX4 (A), GAPDH (B), and total protein staining by Ponceau S stain (C) in left ventricular (LV), right ventricular (RV), and interventricular septal regions (IVS) of dilated cardiomyopathy patients (DCM).
Article
Aims: To determine the specific role of podocyte-expressed cannabinoid-1 receptor (CB1 R) in the development of diabetic nephropathy (DN), relative to CB1 R in other renal cell types. Material and methods: We developed a mouse model with a podocyte-specific deletion of CB1 R (pCB1Rko) and challenged this model with streptozotocin (STZ)-induced t...
Article
Group 2 innate lymphoid cells (ILC2s) represent a rapid source of type 2 cytokines, such as IL-5 and IL-13, and play an important role in orchestrating type 2 immune response. Adenosine is an endogenous purine nucleoside, a catabolite of ATP that binds and activates ≥1 of 4 transmembrane G protein-coupled cell-surface adenosine receptors (ARs)-A1,...
Article
Full-text available
Cannabidiol (CBD) is a non-psychoactive component of marijuana, which has anti-inflammatory effects. It has also been approved by FDA for various orphan diseases for exploratory trials. Herein, we investigated the effects of CBD on liver injury induced by chronic plus binge alcohol feeding in mice. CBD or vehicle was administered daily throughout t...
Article
Full-text available
Adenosine, a key extracellular signaling mediator, regulates several aspects of metabolism by activating 4 G protein-coupled receptors, the A1, A2A, A2B, and A3 adenosine receptors (ARs). The role of A2AARs in regulating high-fat-diet (HFD)-induced metabolic derangements is unknown. To evaluate the role of A2AARs in regulating glucose and insulin h...
Article
Significance: Redox imbalance may lead to overproduction of reactive oxygen and nitrogen species (ROS/RNS) and subsequent oxidative tissue damage which is a critical event in the course of neurodegenerative diseases. It is still not fully elucidated, however, whether oxidative stress is the primary trigger or a consequence in process of neurodegen...
Article
Background and purpose: Glycogen phosphorylase (GP) is the key enzyme for glycogen degradation. GP inhibitors (GPi-s) are glucose lowering agents trapping glucose in the liver as glycogen. Glycogen metabolism has implications in β-cell function; glycogen degradation can maintain cellular glucose levels, which feeds into catabolism to maintain insu...