title: The in vivo expression of dipeptidyl peptidases 8 and 9.
abstract: The dipeptidyl peptidase IV (DPIV) enzyme family contains both potential and proven therapeutic targets. Recent reports indicate the presence of DP8 and DP9 in peripheral blood lymphocytes, testis, lung, and brain. For a more comprehensive understanding of DP8 and DP9 tissue and cellular expression, mRNA and enzyme activity were examined. Many organs from C57BL/6 wild-type and DPIV gene-knockout mice were examined; DP8/9 enzyme activity was detected in the immune system, brain, testis, muscle, and epithelia. In situ hybridization localized DP8 and DP9 mRNA to lymphocytes and epithelial cells in liver, gastrointestinal tract, lymph node, spleen, and lung. DP8 and DP9 mRNA was detected in baboon and mouse testis, and DP9 expression was elevated in human testicular cancers. DP8 and DP9 mRNA were ubiquitous in day 17 mouse embryo, with greatest expression in epithelium (skin and gastrointestinal tract) and brain. Thus, DP8 and DP9 are widely expressed enzymes. Their expression in lymphocytes and epithelia indicates potential for roles in the digestive and immune systems. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.
authors: A.W. Morrow Gastroenterology and Liver Centre, Centenary Institute, Royal Prince Alfred Hospital and the University of Sydney Medical School, Sydney, Australia.
authors: Denise M T
authors: DM
authors: Yu
authors: Katerina
authors: K
authors: Ajami
authors: Margaret G
authors: MG
authors: Gall
authors: Joohong
authors: J
authors: Park
authors: C Soon
authors: CS
authors: Lee
authors: Kathryn A
authors: KA
authors: Evans
authors: Eileen A
authors: EA
authors: McLaughlin
authors: Melissa R
authors: MR
authors: Pitman
authors: Catherine A
authors: CA
authors: Abbott
authors: Geoffrey W
authors: GW
authors: McCaughan
authors: Mark D
authors: MD
authors: Gorrell
mesh_terms: D000293:Adolescent; D000818:Animals; D002490:Central Nervous System / Q000187:drug effects / Q000378:metabolism; D002648:Child; D018819:Dipeptidyl Peptidase 4 / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D054873:Dipeptidyl-Peptidase IV Inhibitors; D004703:Endocrine System / Q000187:drug effects / Q000378:metabolism; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005033:Ethylmaleimide / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D055786:Gene Knockout Techniques; D006801:Humans; D007107:Immune System / Q000187:drug effects / Q000378:metabolism; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D010215:Papio; D011480:Protease Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012098:Reproduction; D013737:Testis / Q000187:drug effects / Q000378:metabolism
chemical_list: D054873:Dipeptidyl-Peptidase IV Inhibitors; D011480:Protease Inhibitors; D012333:RNA, Messenger; D018819:Dipeptidyl Peptidase 4; D005033:Ethylmaleimide