INOSITOL PHOSPHATE REMEDIATION OF CL- SECRETORY DEFECTS

DESCRIPTION (Adapted from applicant's abstract): Cystic fibrosis (CF) is due to various defects in an apical epithelial Cl- channel, the cystic fibrosis transmembrane regulator (CFTR). The disease can usually be traced to a single point mutation in CFTR that renders it incapable of transfer to the outer membrane. One potential approach to managing the disease could be the artificial activation of Ca2+- dependent Cl- channels also abundant in epithelial cells. However, this speculative therapeutic pathway is currently ineffective because the cholinergic stimulation of intracellular Ca2+ is accompanied by a slow and prolonged increase in intracellular Ins(3,4,5,6)P4 (IP4) levels. The applicant has previously identified IP4 as an endogenous negative regulator of Ca2+-dependent Cl- transport in epithelial cells. In this study, a series of compounds with characteristics of IP4 antagonists will be tested to assess their potential use as treatments for CF. CTFR(-) epithelial cell mutants will be developed to determine if CFTR regulates the expression of elements involved in IP4-mediated inhibition of Cl- secretion. The IP4 antagonists will be tested in a non-transformed pancreatic cell line (PDEC) which has been shown to have a Ca2+-dependent Cl- conductance and in a CFTR(-) human cell line. The applicant will also determine the effects of the compounds on Cl- secretion in human airway epithelia derived from normal and CF patients. These studies will determine the range of tissues that would be appropriate targets for modulation by inositol polyphosphate derivatives and whether they will augment Cl- secretion in diseased as well as in normal epithelia. $ = TOTAL AWARD AMTS & NOT LIMITED TO PORTION OF PROJECT RELATED TO SUBJECT OF SEARCH SUBPROJECT $ = TOTAL AWARD AMOUNT DIVIDED BY NUMBER OF SUBPROJECTS SOURCE: CRISP FORMAT F FY 97 LAST UPDATE 04-07-98 1QUERY 1536 ID SEARCH 06/01/98 PAGE 269 --PROJECT NUMBER......1 R43 DK52737-01A1 INVESTIGATOR NAME/ADDRESS FY 97 PYKETT, MARK J IRG/INTRAMURAL UNIT..ZRG2 CYTOMATRIX AWARD AMOUNT......... $94,000 100 INMAN ST, SUITE 104 CAMBRIDGE, MA 02139 PERFORMING ORGANIZATION: CYTOMATRIX TITLE CYTOKINE EFFECTS ON STEM CELLS USING A NOVEL BIOREACTOR ABSTRACT: This Phase I project will examine the effects of cytokines on hematopoietic progenitor cells (HPCs) using a novel three-dimensional biomaterial, Cellfoam TM . Preliminary work has shown that Cellfoam enables the culture of CD34+/CD38- HPCs and the maintenance of their multipotent and immature phenotype for periods of up to three weeks in the absence of supplemented cytokines. This unique capability will be exploited in Phase 1 to examine the effects of specific cytokines (IL-3, IL-6 and stem cell factor), individually and in groups, on HPC biology. Operating from the hypothesis that the addition of cytokines to cultures of HPCs in vitro will affect HPC survival and multipotency, this project will specifically focus on measuring the survival, phenotype and multipotency of HPCs cultured in Cellfoam for periods of three days to six weeks in the presence and absence of supplemented cytokines. This will allow a direct determination of the effects of selected cytokines on HPC biology in an environment that does not have an absolute requirement for cytokines in long-term HPC culturing. The findings of the Phase 1 research will be instrumental in the Phase Il development of Cellfoam systems enabling the maintenance and manipulation of stem cells over extended periods for clinical and research uses.