1998 — 2002 |
Wetsel, William C |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Genetic Rescue of Pro-Lhrh Processing in Cpe Fat Mice
Luteinizing hormone-releasing hormone (LHRH) is a major regulator of reproduction in mammals. This decapeptide is processed from prohormone, pro-LHRH. At least four different enzymatic steps are involved in the conversion of pro-LHRH to LHRH. One of these processing enzymes may be carboxypeptidase E (CPE). Recently, a mouse line was identified with a point mutation in CPE. These CPEfat mice are obese, diabetic, and infertile. The overall objective of the proposal is to determine whether CPE is involved in processing the pro-LHRH in vivo and whether a defect in this enzyme is responsible for the infertility in the CPEfat mouse. Aim I: There are four aspects to this first specific aim. First, processing of pro-LHRH will be examined in hypothalami from male and female wild type, heterozygous, and homozygous CPEfat mice. These data should identify which steps in pro-LHRH processing are deficient in the homozygotes. Second, LHRH gene expression and pro-LHRH biosynthesis will be compared among the groups of mice. Third, since pro-LHRH processing may involve three different enzymes besides CPE, expression of these enzymes will also be studied. Fourth, biological activity of the various pro-LHRH intermediates will be assessed in dispersed anterior pituitary cultures from these groups of mice. Finally, the hypothalamus, pituitary and gonads will be evaluated to determine whether the mutation in CPE affects additional responses from these organs. Aim II: A transgenic approach will be used to rescue the CPEfat phenotype and restore processing of the pro-LHRH to LHRH. In this case, mice will be genetically targeted for CPE expression in hypothalamic LHRH neurons. These transgenic mice will be bred with heterozygous CPEfat mice to produce a mouse that is homozygous for the CPEfat mutation, but has CPE selectively expressed in LHRH neurons. The abilities of these mice to process pro-LHRH to LHRH and responses from the gonads, pituitary and hypothalamus will be evaluated as in Aim I. Aim III: Mice homozygous for the CPEfat mutation that have selective expression of CPE in LHRH neurons will be evaluated for their abilities to reproduce. This series of experiments in the CPEfat mouse presents us with the unique opportunity to clearly link a deficiency in pro-LHRH processing with a defect in reproduction. The biochemical, physiological, and gene-targeting principles derived from this work should broaden our understanding of basic mechanisms that regulate reproduction in mammals and it may serve as a useful example for repairing genetically-based diseases or other defects in the future.
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1 |
2013 — 2014 |
Kozikowski, Alan Paul [⬀] Roth, Bryan L. (co-PI) [⬀] Wetsel, William C |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Optimizing Lead 5-Ht2c Ligands For Use in the Treatment of Schizophrenia @ University of Illinois At Chicago
DESCRIPTION (provided by applicant): Our ultimate goal is to synthesize and characterize novel 5-HT2c serotonin agonists that may be useful for treating schizophrenia and related disorders. Our preliminary findings, as well as those of others, indicate that 5-HT2C agonists are effective in animal models predictive of efficacy against the positive and cognitive symptoms of schizophrenia. Because 5-HT2C agonists are not associated with the metabolic and motoric side- effects characteristic of current typical and atypical antipsychotic drugs, 5-HT2C agonists would afford novel treatment strategies for schizophrenia and related disorders. To achieve this overall goal we have three specific aims. Aim 1: To further expand and improve upon the potent 5-HT2c ligands that we have already identified using rational drug design principles and chemical intuition. Structural alterations will be made to enhance 5-HT2c subtype selectivity and to avoid any 5-HT2B valvuopathic-associated activity, while also improving upon compound solubility and ADMET parameters as needed to achieve the desired efficacy in preclinical animal studies. Aim 2: Characterize binding affinities and functional activities of putative 5-HT2c agonists for the human and mouse 5-HT2c-INI, 5-HT2c-NVN and 5-HT2c-VSV receptor-isoforms. We will also evaluate specificity of putative 5-HT2c agonists by assessing 5-HT2A and 5-HT2B receptor activities by radioligand binding and functional assays. The best compounds emerging from these studies will be subjected to a large battery of assays for identification of off-target activity. Aim 3: To evaluate the best 5-HT2c ligands identified in Specific Aims 1 and 2 in a battery of schizophrenia- related behavioral assays to test for antipsychotic efficacy and possible pro-cognitive effects. The behavioral studies will be conducted with pharmacological and genetic models of schizophrenia-like behaviors; 5-HT2C- knockout mice will serve as controls. The strength of this proposal lies in: (1) Targeting a receptor for which there are no currently approved medications (i.e. a novel molecular target); (2) 5-HT2C agonists are likely to have clinical indications beyond schizophrenia including bipolar disorder, depression, obesity, and drug abuse (i.e. many potential clinical indications); (3) With respect to schizophrenia, two different 5-HT2C agonists have already shown efficacy in animal models predictive of efficacy for positive- and cognitive-like schizophrenia symptoms. Since cognitive symptoms are very difficult to treat in schizophrenia, the 5-HT2C compounds may represent a novel treatment strategy; (4) Finally, it is likely that 5-HT2C agonists will not only be devoid of the metabolic ad motoric side- effects associated with current medications but may also be beneficial from a metabolic perspective.
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0.97 |