Thiocyanate Reduces Motor Impairment in the hMPO-A53T PD Mouse Model While Reducing MPO-Oxidation of Alpha Synuclein in Enlarged LYVE1/AQP4 Positive Periventricular Glymphatic Vessels.

Parkinson's disease (PD) is due to the oxidation of alpha synuclein (αSyn) contributing to motor impairment. We developed a transgenic mouse model of PD that overexpresses the mutated human αSyn gene (A53T) crossed to a mouse expressing the human MPO gene. This model exhibits increased oxidation and chlorination of αSyn leading to greater motor impairment.

Human myeloperoxidase (hMPO) is expressed in neurons in the substantia nigra in Parkinson's disease and in the hMPO-α-synuclein-A53T mouse model, correlating with increased nitration and aggregation of α-synuclein and exacerbation of motor impairment.

α-Synuclein (αSyn) is central to the neuropathology of Parkinson's disease (PD) due to its propensity for misfolding and aggregation into neurotoxic oligomers. Nitration/oxidation of αSyn leads to dityrosine crosslinking and aggregation. Myeloperoxidase (MPO) is an oxidant-generating enzyme implicated in neurodegenerative diseases.

Myeloperoxidase-catalyzed oxidation of cyanide to cyanate: A potential carbamylation route involved in the formation of atherosclerotic plaques?

Protein carbamylation by cyanate is a post-translational modification associated with several (patho)physiological conditions, including cardiovascular disorders. However, the biochemical pathways leading to protein carbamylation are incompletely characterized. This work demonstrates that the heme protein myeloperoxidase (MPO), which is secreted at high concentrations at inflammatory sites from stimulated neutrophils and monocytes, is able to catalyze the two-electron oxidation of cyanide to cyanate and promote the carbamylation of taurine, lysine, and low-density lipoproteins.

T47D Cells Expressing Myeloperoxidase Are Able to Process, Traffic and Store the Mature Protein in Lysosomes: Studies in T47D Cells Reveal a Role for Cys319 in MPO Biosynthesis that Precedes Its Known Role in Inter-Molecular Disulfide Bond Formation.

Among the human heme-peroxidase family, myeloperoxidase (MPO) has a unique disulfide-linked oligomeric structure resulting from multi-step processing of the pro-protein monomer (proMPO) after it exits the endoplasmic reticulum (ER). Related family members undergo some, but not all, of the processing steps involved with formation of mature MPO. Lactoperoxidase has its pro-domain proteolytically removed and is a monomer in its mature form.

Association of myeloperoxidase with ovarian cancer.

Myeloperoxidase (MPO) is an oxidant generating enzyme normally restricted to myeloid cells, however aberrant MPO expression has been found to occur in non-myeloid cells in some disease states. The functional -463GA promoter polymorphism alters MPO expression levels. The -463G is within an SP1 binding site and is associated with higher gene expression.

Reproductive physiology of a humanized GnRH receptor mouse model: application in evaluation of human-specific analogs.

The human GnRH receptor (GNRHR1) has a specific set of properties with physiological and pharmacological influences not appropriately modeled in laboratory animals or cell-based systems. To address this deficiency, we have generated human GNRHR1 knock-in mice and described their reproductive phenotype. Measurement of pituitary GNRHR1 transcripts from homozygous human GNRHR1 knock-in (ki/ki) mice revealed a severe reduction (7- to 8-fold) compared with the mouse Gnrhr1 in wild-type mice.

Aberrant expression of myeloperoxidase in astrocytes promotes phospholipid oxidation and memory deficits in a mouse model of Alzheimer disease.

Myeloperoxidase (MPO) is expressed in Alzheimer disease (AD) but not normal aged brain. A functional -463G/A MPO promoter polymorphism has been associated with AD risk through as yet unidentified mechanisms. Here we report that human MPO-463G allele, but not MPO-463A or mouse MPO, is strongly expressed in astrocytes and deposited in plaques in huMPO transgenic mice crossed to the APP23 model.

Human endometriosis is associated with plasma cells and overexpression of B lymphocyte stimulator.

Endometriosis affects 10-20% of women of reproductive age and is associated with pelvic pain and infertility, and its pathogenesis is not well understood. We used genomewide transcriptional profiling to characterize endometriosis and found that it exhibits a gene expression signature consistent with an underlying autoimmune mechanism. Endometriosis lesions are characterized by the presence of abundant plasma cells, many of which produce IgM, and macrophages that produce BLyS/BAFF/TNFSF13B, a member of the TNF superfamily implicated in other autoimmune diseases.

NMR structural characterization of a minimal peptide antagonist bound to the extracellular domain of the corticotropin-releasing factor1 receptor.

Natural peptide agonists of corticotrophin-releasing factor (CRF) receptors bind to the receptor by a two-site mechanism as follows: the carboxyl end of the ligand binds the N-terminal extracellular domain (ECD) of the receptor and the amino portion of the ligand binds the extracellular face of the seven transmembrane region. Recently, peptide antagonists homologous to the 12 C-terminal residues of CRF have been derived, which bind the CRF(1) receptor through an interaction with the ECD. Here we characterized the binding of a minimal 12-residue peptide antagonist while bound to the isolated ECD of the CRF(1) receptor.

Pharmacological characterization of a novel nonpeptide antagonist of the human gonadotropin-releasing hormone receptor, NBI-42902.

Suppression of the hypothalamic-pituitary-gonadal axis by peptides that act at the GnRH receptor has found widespread use in clinical practice for the management of sex-steroid-dependent diseases (such as prostate cancer and endometriosis) and reproductive disorders. Efforts to develop orally available GnRH receptor antagonists have led to the discovery of a novel, potent nonpeptide antagonist, NBI-42902, that suppresses serum LH concentrations in postmenopausal women after oral administration. Here we report the in vitro and in vivo pharmacological characterization of this compound.

Manipulation of small-molecule inhibitory kinetics modulates MCH-R1 function.

The capacity of novel benzopyridazinone-based antagonists to inhibit MCH-R1 function, relative to their affinity for the receptor, has been investigated. Three compounds that differ by the addition of either a chlorine atom, or trifluoromethyl group, have nearly identical receptor affinities; however their abilities to inhibit receptor elicited signaling events, measured as a function of time, are dramatically altered. Both the chlorinated and trifluoromethyl modified compounds have a very slow on-rate to maximal functional inhibition relative to the unmodified base compound.

A point mutation in the human melanin concentrating hormone receptor 1 reveals an important domain for cellular trafficking.

G protein-coupled receptors (GPCRs) are heptahelical integral membrane proteins that require cell surface expression to elicit their effects. The lack of appropriate expression of GPCRs may be the underlying cause of a number of inherited disorders. There is evidence that newly synthesized GPCRs must attain a specific conformation for their correct trafficking to the cell surface.

Distinct conformations of the corticotropin releasing factor type 1 receptor adopted following agonist and antagonist binding are differentially regulated.

The corticotropin releasing factor (CRF) type 1 receptor (CRF1) is a class B family G protein-coupled receptor that regulates the hypothalamic-pituitary-adrenal stress axis. Astressin is an amino-terminal truncated analog of CRF that retains high affinity binding to the extracellular domain of the receptor and is believed to act as a neutral competitive antagonist of receptor activation. Here we show that despite being unable to activate the CRF1 receptor, astressin binding results in the internalization of the receptor.

Interleukin-4 receptor cytotoxin as therapy for human malignant pleural mesothelioma xenografts.

Background: Malignant pleural mesothelioma (MPM) is an uncommon but highly fatal neoplasm for which only limited treatment is available.

Methods: Immunohistochemical analysis was used to determine the expression of interleukin-4 receptors (IL-4R) on mesothelioma cell lines and resected mesothelioma tumors. Radioreceptor binding assays were used to show that these IL-4R were high-affinity receptors.

Cuttine edge: diabetes-associated quantitative trait locus, Idd4, is responsible for the IL-12p40 overexpression defect in nonobese diabetic (NOD) mice.

APCs of the nonobese diabetic (NOD) mouse have a genetically programmed capacity to overexpress IL-12p40, a cytokine critical for development of pathogenic autoreactive Th1 cells. To determine whether a diabetes-associated NOD chromosomal locus (i.e.

Differential kinetics of hypocretins in the cerebrospinal fluid after intracerebroventricular administration in rats.

Different potencies for hypocretin-1 and -2 in sleep-wake regulation and feeding after intracerebroventricular (ICV) administration have been reported. These differences were often explained by the selectivity of the two hypocretins for hypocretin receptor-1 and -2, but little attention has been paid to kinetics of hypocretin peptides. We investigated the kinetics of the ICV hypocretin-1 and -2 in rats.

Molecular determinants of melanocortin 4 receptor ligand binding and MC4/MC3 receptor selectivity.

The molecular basis of ligand recognition by the melanocortin 4 receptor (MC4R) has not been fully defined. In this study, we investigated the molecular determinants of MC4R ligand binding, employing a large array of ligands, using three approaches. First, molecular modeling of the receptor was used to identify Phe284, in transmembrane (TM) 7, as a potential site of ligand interaction.

Interleukin 4 receptor on human lung cancer: a molecular target for cytotoxin therapy.

Previous studies have demonstrated that human lung tumor cell lines express interleukin 4 (IL-4) receptors, and IL-4 can mediate modest to moderate antiproliferative activity in vitro and in vivo in animal models of human lung tumors. On the basis of these studies, IL-4 was tested in clinical trials; however, it showed little antitumor activity in lung cancer patients. In the present study, we examined the expression of IL-4 receptors (IL-4Rs) in lung tumor samples and normal lung tissues and tested whether an IL-4R targeted agent will have better antitumor activity in vitro and in vivo compared with IL-4.

Identification of three genes up-regulated in PU.1 rescued monocytic precursor cells.

The requirement of the transcription factor PU.1 for macrophage development has been well documented. However, the target genes regulated by PU.

Identification of differentially expressed genes induced by transient ischemic stroke.

We have used a rat model of focal cerebral ischemia to investigate changes in gene expression that occur during stroke. To monitor these changes, we employed representational difference analysis-polymerase chain reaction (PCR). A total of 128 unique gene fragments were isolated, and we selected 13 of these for quantitative reverse transcriptase-PCR analysis.

Interleukin 4 receptor-directed cytotoxin therapy for human head and neck squamous cell carcinoma in animal models.

Receptors for interleukin 4 (IL-4R) are overexpressed on the surface of various human solid tumors including renal cell carcinoma, glioblastoma, Kaposi's sarcoma, and head and neck squamous cell carcinoma (SCCHN). On the basis of this preferential receptor overexpression, a novel IL-4R-targeted cytotoxin, IL-4 (38-37)-PE38KDEL, was developed in which circularly permuted IL-4 [IL-4 (38-37)] was fused to mutated form of Pseudomonas exotoxin (PE38KDEL). Despite the recognized expression of the IL-4R on SSCHN, the utility of a receptor-specific fusion protein for the treatment of this disease remains unknown.