Inhibition of Na/K-ATPase signaling Attenuates Steatohepatitis and Atherosclerosis in Mice Fed a Western Diet.

We have previously reported that the α1 subunit of sodium-potassium adenosine triphosphatase (Na/K-ATPase), acts as a receptor and an amplifier for reactive oxygen species, in addition to its distinct pumping function. On this background, we speculated that the blockade of Na/K-ATPase-induced ROS amplification with a specific peptide, pNaKtide, might attenuate the development of steatohepatitis. To test this hypothesis, pNaKtide was administered to a murine model of NASH: the C57Bl6 mouse fed a "western" diet containing high amounts of fat and fructose. The administration of pNaKtide reduced obesity as well as hepatic steatosis, inflammation and fibrosis. Of interest, we also noted a marked improvement in mitochondrial fatty acid oxidation, insulin sensitivity, dyslipidemia and aortic streaking in this mouse model. To further elucidate the effects of pNaKtide on atherosclerosis, similar studies were performed in ApoE knockout mice also exposed to the western diet. In these mice, pNaKtide not only improved steatohepatitis, dyslipidemia, and insulin sensitivity but also ameliorated significant aortic atherosclerosis. Collectively, this study demonstrates that the Na/K-ATPase/ROS amplification loop contributes significantly to the development and progression of steatohepatitis and atherosclerosis. Furthermore, this study presents a potential treatment, the pNaKtide, for the metabolic syndrome phenotype.

The Na/K-ATPase Oxidant Amplification Loop Regulates Aging.

As aging involves oxidant injury, we examined the role of the recently described Na/K-ATPase oxidant amplification loop (NKAL). First, C57Bl6 old mice were given a western diet to stimulate oxidant injury or pNaKtide to antagonize the NKAL. The western diet accelerated functional and morphological evidence for aging whereas pNaKtide attenuated these changes. Next, human dermal fibroblasts (HDFs) were exposed to different types of oxidant stress in vitro each of which increased expression of senescence markers, cell-injury, and apoptosis as well as stimulated the NKAL. Further stimulation of the NKAL with ouabain augmented cellular senescence whereas treatment with pNaKtide attenuated it. Although N-Acetyl Cysteine and Vitamin E also ameliorated overall oxidant stress to a similar degree as pNaKtide, the pNaKtide produced protection against senescence that was substantially greater than that seen with either antioxidant. In particular, pNaKtide appeared to specifically ameliorate nuclear oxidant stress to a greater degree. These data demonstrate that the NKAL is intimately involved in the aging process and may serve as a target for anti-aging interventions.

Heme Oxygenase Induction Suppresses Hepatic Hepcidin and Rescues Ferroportin and Ferritin Expression in Obese Mice.

Hepcidin, a phase II reactant secreted by hepatocytes, regulates cellular iron levels by increasing internalization of ferroportin-a transmembrane protein facilitating egress of cellular iron. Chronic low-grade inflammatory states, such as obesity, have been shown to increase oxidative stress and enhance hepcidin secretion from hepatocytes and macrophages. Heme-heme oxygenase (HO) is a stress response system which reduces oxidative stress. We investigated the effects of HO-1 induction on hepatic hepcidin levels and on iron homeostasis in hepatic tissues from lean and obese mice. Obese mice exhibited hyperglycemia (p < 0.05); increased levels of proinflammatory cytokines (MCP-1, IL-6, p < 0.05); oxidative stress (p < 0.05); and increased hepatic hepcidin levels (p < 0.05). Enhancement of hepcidin was reflected in the reduced expression of ferroportin in obese mice (p < 0.05). However, this effect is accompanied by a significant decline in ferritin expression. Additionally, there are reduced insulin receptor phosphorylation and attenuation of metabolic regulators pAMPK, pAKT, and pLKB1. Cobalt protoporphyrin- (CoPP-) induced HO-1 upregulation in obese mice reversed these alterations (p < 0.05), while attenuating hepatic hepcidin levels. These effects of CoPP were prevented in obese mice concurrently exposed to an inhibitor of HO (SnMP) (p < 0.05). Our results highlight a modulatory effect of HO on iron homeostasis mediated through the suppression of hepatic hepcidin.

Creating a Biomarker Panel for Early Detection of Chemotherapy Related Cardiac Dysfunction in Breast Cancer Patients.

Cardiotoxicity is an important issue for breast cancer patients receiving anthracycline-trastuzumab therapy in the adjuvant setting. Studies show that 3-36% of patients receiving anthracyclines and/or trastuzumab experience chemotherapy related cardiac dysfunction (CRCD) and approximately 17% of patients must stop chemotherapy due to the consequences of CRCD. There is currently no standardized, clinically verified way to detect CRCD early, but common practices include serial echocardiography and troponin measurements, which can be timely, costly, and not always available in areas where health care resources are scarce. Furthermore, detection of CRCD, before there is any echocardiographic evidence of dysfunction or clinical symptoms present, would allow maximal benefit of chemotherapy and minimize cardiac complications. Creating a panel of serum biomarkers would allow for more specificity and sensitivity in the early detection of CRCD, which would be easy to implement and cost effective in places with limited health care. Based on a review of the literature, we propose creating a biomarker panel consisting of topoisomerase 2ß, serum troponin T/I, myeloperoxidase, NT-proBNP, miR-208b, miR-34a, and miR-150 in breast cancer patients receiving anthracyclines and/or trastuzumab to detect CRCD before any signs of overt cardiotoxicity are apparent.

Existence of a Strong Correlation of Biomarkers and miRNA in Females with Metabolic Syndrome and Obesity in a Population of West Virginia.

Objectives: Metabolic syndrome causes complications like cardiovascular disease and type 2 diabetes mellitus (T2DM). As metabolic syndrome develops, altered levels of cytokines and microRNAs (miRNA) are measurable in the circulation. We aimed to construct a panel detecting abnormal levels of cytokines and miRNAs in patients at risk for metabolic syndrome. Methods: Participants included 54 patients from a Family Medicine Clinic at Marshall University School of Medicine, in groups of: Control, Obese, and Metabolic Syndrome (MetS). Results: Serum levels of leptin, adiponectin, leptin: adiponectin ratio, IL-6, six miRNAs (320a, 197-3p, 23-3p, 221-3p, 27a-3p, and 130a-3p), were measured. Among the three groups, leptin, and leptin: adiponectin ratio, and IL-6 levels were highest in MetS, and levels in Obese were greater than Control (p>0.05). Adiponectin levels were lower in Obese compared to Control, but lowest in MetS (p<0.05). MiRNAs levels were lowest in MetS, and levels in Obese were lower than Control (p>0.05). Conclusion: Our results support the clinical application of biomarkers in diagnosing early stage MetS, which will enable attenuation of disease progression before onset of irreversible complications. Since West Virginians are high-risk for developing MetS, our biomarker panel could reduce the disease burden on our population.

pNaKtide Attenuates Steatohepatitis and Atherosclerosis by Blocking Na/K-ATPase/ROS Amplification in C57Bl6 and ApoE Knockout Mice Fed a Western Diet.

We have previously reported that the α1 subunit of sodium potassium adenosine triphosphatase (Na/K-ATPase), acts as a receptor and an amplifier for reactive oxygen species, in addition to its distinct pumping function. On this background, we speculated that blockade of Na/K-ATPase-induced ROS amplification with a specific peptide, pNaKtide, might attenuate the development of steatohepatitis. To test this hypothesis, pNaKtide was administered to a murine model of NASH: the C57Bl6 mouse fed a "western" diet containing high amounts of fat and fructose. The administration of pNaKtide reduced obesity as well as hepatic steatosis, inflammation and fibrosis. Of interest, we also noted marked improvement in mitochondrial fatty acid oxidation, insulin sensitivity, dyslipidemia and aortic streaking in this mouse model. To further elucidate the effects of pNaKtide on atherosclerosis, similar studies were performed in ApoE knockout mice also exposed to the western diet. In these mice, pNaKtide not only improved steatohepatitis, dyslipidemia, and insulin sensitivity, but also ameliorated significant aortic atherosclerosis. Collectively, this study demonstrates that the Na/K-ATPase/ROS amplification loop contributes significantly to the development and progression of steatohepatitis and atherosclerosis. And furthermore, this study presents a potential treatment, the pNaKtide, for the metabolic syndrome phenotype.

The Role of Na/K-ATPase Signaling in Oxidative Stress Related to Obesity and Cardiovascular Disease.

Na/K-ATPase has been extensively studied for its ion pumping function, but, in the past several decades, has been identified as a scaffolding and signaling protein. Initially it was found that cardiotonic steroids (CTS) mediate signal transduction through the Na/K-ATPase and result in the generation of reactive oxygen species (ROS), which are also capable of initiating the signal cascade. However, in recent years, this Na/K-ATPase/ROS amplification loop has demonstrated significance in oxidative stress related disease states, including obesity, atherosclerosis, heart failure, uremic cardiomyopathy, and hypertension. The discovery of this novel oxidative stress signaling pathway, holds significant therapeutic potential for the aforementioned conditions and others that are rooted in ROS.

Role of Serum Biomarkers in Early Detection of Non-Alcoholic Steatohepatitis and Fibrosis in West Virginian Children.

BACKGROUND: Obesity, an epidemic among West Virginia children, as well as insulin resistance (IR), is well-established contributors to nonalcoholic steatohepatitis (NASH). Progression of NASH can lead to hepatic fibrosis and cirrhosis, making early detection imperative. The standard for diagnosing NASH is histologically via liver biopsy, which is highly invasive and generally contraindicated in children. By studying serum biomarkers associated with NASH, we aim to identify high risk children who can benefit from a less invasive, alternative approach to the early detection of NASH. METHODS: Seventy one children were prospectively recruited and divided into 3 groups: normal weight without IR (control), obese without IR, and obese with IR. Serum samples were drawn for each patient and biomarker levels were assessed via ELISA kits. RESULTS: Obese without IR and obese with IR patients had significantly elevated levels of lipid metabolism and accumulation markers (FGF-21, NEFA, FATP5, ApoB), oxidative stress markers (dysfunctional HDL, 8-Isoprostane), inflammatory markers(dysfunctional HDL, CK-18) and apoptosis markers (CK-18) compared to control patients (p<0.02). Bilirubin (an antioxidant) was significantly decreased in the obese without IR and obese with IR patients compared to control (p<0.02). CONCLUSION: This study showed a correlation between obesity, IR, and biomarkers associated with NASH in pediatrics patients from West Virginia, with obese with IR patients showing the strongest correlation. These findings support the clinical application of these serum biomarkers as a less invasive method for early detection of NASH and hepatic fibrosis.

Systematic Review of Metabolic Syndrome Biomarkers: A Panel for Early Detection, Management, and Risk Stratification in the West Virginian Population.

INTRODUCTION: Metabolic syndrome represents a cluster of related metabolic abnormalities, including central obesity, hypertension, dyslipidemia, hyperglycemia, and insulin resistance, with central obesity and insulin resistance in particular recognized as causative factors. These metabolic derangements present significant risk factors for cardiovascular disease, which is commonly recognized as the primary clinical outcome, although other outcomes are possible. Metabolic syndrome is a progressive condition that encompasses a wide array of disorders with specific metabolic abnormalities presenting at different times. These abnormalities can be detected and monitored via serum biomarkers. This review will compile a list of promising biomarkers that are associated with metabolic syndrome and this panel can aid in early detection and management of metabolic syndrome in high risk populations, such as in West Virginia. METHODS: A literature review was conducted using PubMed, Science Direct, and Google Scholar to search for markers related to metabolic syndrome. Biomarkers searched included adipokines (leptin, adiponectin), neuropeptides (ghrelin), pro-inflammatory cytokines (IL-6, TNF-α), anti-inflammatory cytokines (IL-10), markers of antioxidant status (OxLDL, PON-1, uric acid), and prothrombic factors (PAI-1). RESULTS: According to the literature, the concentrations of pro-inflammatory cytokines (IL-6, TNF-α), markers of pro-oxidant status (OxLDL, uric acid), and prothrombic factors (PAI-1) were elevated in metabolic syndrome. Additionally, leptin concentrations were found to be elevated in metabolic syndrome as well, likely due to leptin resistance. In contrast, concentrations of anti-inflammatory cytokines (IL-10), ghrelin, adiponectin, and antioxidant factors (PON-1) were decreased in metabolic syndrome, and these decreases also correlated with specific disorders within the cluster. CONCLUSION: Based on the evidence presented within the literature, the aforementioned biomarkers correlate significantly with metabolic syndrome and could provide a minimally-invasive means for early detection and specific treatment of these disorders. Further research is encouraged to determine the efficacy of applying these biomarkers to diagnosis and treatment in a clinical setting.

Free-flap failure in thrombophilia: case report and systematic review of the literature.

Free-tissue transfer has become routine surgery because of standardization of instrumentation, techniques, and training. The incidence of microvascular thrombosis leading to free-flap failure is relatively low; however, anastomotic thrombosis can still occur despite the best of circumstances. Although majority of the time it is due to technical mishap or misjudgment, free-flap failure can occur due to intrinsic factors, such as the patient's increased propensity to develop clots. We describe a case report of a patient with malignancy and multiple thrombophilias, which led to 2 successive failures in microvascular flap transfer to restore abdominal domain. The aim o f this article is to increase awareness of the potential for thrombophilias to cause a dismal outcome in free-tissue transfer. A review of the literature will be presented, and published cases of free-flap failure in patients with thrombophilia(s) will be summarized.