Lane L. Clarke, DVM, PhD

Email: ClarkeL@missouri.edu

Research Interests: Cystic fibrosis and epithelial transport of ions and nutrients.

Teaching: Gastrointestinal physiology and pharmacology

Dr. Clarke's laboratory investigates electrolyte and nutrient transport across epithelial tissues (airway, reproductive and intestinal) during health and disease. The major focus is to understand the role of the cystic fibrosis transmembrane conductance regulator protein (CFTR) in the regulation of acid-base and nutrient transport across alimentary epithelia. CFTR is the protein product of the gene that is mutated in cystic fibrosis (CF) and normally functions in epithelial cells as a cyclic AMP-regulated anion channel. Present studies investigate the role of anion exchange proteins that work with CFTR in promoting bicarbonate transport or that work with Na+ transport proteins for NaCl absorption across intestinal epithelium. Most studies involve either measurements of acid-base or nutrient transporter activity using fluorescent dyes to monitor intracellular pH by microfluorimetry or electrophysiological recordings in Ussing chambers of native mucosa and cell lines derived from gene-targeted (“knockout”) mice. In addition to the cystic fibrosis mice, the laboratory maintains colonies of mice with gene-targeted deletion of other acid-base transporting proteins, including Na+/H+ exchangers, Cl-/HCO3- exchangers and H+/K+ ATPases. Molecular studies in the laboratory involve the measurements of gene expression in the mice (quantitative real-time PCR, Northern blots, microarrays) and cloning of specific murine transporters for functional expression studies in heterologous cell systems. In addition to the above methods, other techniques employed in the laboratory include cell culture, retroviral and adenoviral gene transfer, pH stat/isotopic flux studies and PCR based genotyping.

Publications:
Clarke LL, Grubb BR, Gabriel SE, Smithies O, Koller BH, and Boucher RC. Defective epithelial chloride transport in a gene-targeted mouse model of cystic fibrosis. Science, 257:1125-1128. 1992.

Clarke LL, Grubb BR, Yankaskas JR, Cotton CU, McKenzie A, and Boucher RC. Relationship of a non-CFTR-mediated chloride conductance to organ-level disease in cftr (-/-) mice. Proc. Natl. Acad. Sci. 91(2):479-483, 1994.

Gawenis, LR, Franklin, CL, Simpson, JE, Palmer, BA, Walker, NM, Wiggins, TM and Clarke, LL. cAMP inhibition of murine intestinal Na+/H+ exchange requires CFTR-mediated cell shrinkage of villus epithelium. Gastroenterology 125: 1124-1148, 2003.

Gawenis, LR, Boyle, KT, Palmer, BA, Walker, NM, and Clarke, LL. Lateral intercellular space volume as a determinant of CFTR-mediated anion secretion across small intestinal mucosa. Am. J. Physiol. 286: G1015-G1023, 2004.

Clarke, LL, Gawenis, LR, Hwang, T-C, Gruis, DB and Price, EM. A domain mimic increases DF508 CFTR trafficking and restores cAMP-stimulated anion secretion in cystic fibrosis epithelia. Am. J. Physiol. 287: C192-C199, 2004.

Gawenis, LR, Hut, H, Bot, AGM, Shull, GE, De Jonge, HR, Stein, X, Miller, ML and Clarke, LL. Electroneutral sodium absorption and electrogenic anion secretion across murine small intestine are regulated in parallel. Am. J. Physiol. 287: G1140-G1149, 2004.