tailieunhanh - Báo cáo khoa học: Distribution of the lipolysis stimulated receptor in adult and embryonic murine tissues and lethality of LSR–/–

The lipolysis stimulated receptor (LSR) recognizes apo-lipoprotein B/E-containing lipoproteins in the presence of free fattyacids, and is thought tobe involved in the clearance of triglyceride-rich lipoproteins (TRL). The distribution of LSR in mice was studied by Northern blots, quantitative PCR and immunofluorescence. In the adult,LSRmRNA was detectable in all tissues tested except muscle and heart, and was abundant in liver, lung, intestine, kidney, ovaries and testes. During embryogenesis, LSR mRNA was detectable at days post-coitum (E7) and increased up to E17 inparallel toprothrombin, a livermarker. . | Eur. J. Biochem. 271 3103-3114 2004 FEBS 2004 doi Distribution of the lipolysis stimulated receptor in adult and embryonic murine tissues and lethality of LSR embryos at to days of gestation Samir Mesli1 Sandrine Javorschi1 t Annie M. Berard1 Marc Landry2 Helen Priddle3 David Kivlichan3 Andrew J. H. Smith3 Frances T. Yen4 Bernard E. Bihain4 and Michel Darmon1 1 Laboratoire de Biochimie et de Biologie Moleculaire Universite Victor Segalen Bordeaux 2 France 2INSERM E358 Universite Victor Segalen Bordeaux 2 France 3Gene Targeting Laboratory Center for Genome Research University of Edinburgh Scotland 4Laboratoire Medecine et Therapeutique Moleculaire Vandoeuvre-les-Nancy France The lipolysis stimulated receptor LSR recognizes apolipoprotein B E-containing lipoproteins in the presence of free fatty acids and is thought to be involved in the clearance of triglyceride-rich lipoproteins TRL . The distribution of LSR in mice was studied by Northern blots quantitative PCR and immunofluorescence. In the adult LSR mRNA was detectable in all tissues tested except muscle and heart and was abundant in liver lung intestine kidney ovaries and testes. During embryogenesis LSR mRNA was detectable at days post-coitum E7 and increased up to E17 in parallel to prothrombin a liver marker. In adult liver immunofluorescence experiments showed a staining at the periphery of hepatocytes as well as in fetal liver at E12 and E15. These results are in agreement with the assumption that LSR is a plasma membrane receptor involved in the clearance of lipoproteins by liver and suggest a possible role in steroidogenic organs lung intestine and kidney . To explore the role of LSR in vivo the LSR gene was inactivated in 129 Ola ES cells by removing a gene segment containing exons 2-5 and 129 Ola-C57BL 6 mice bearing the deletion were produced. Although heterozygotes appeared normal LSR homozygotes were not viable with the exception of three males while .