Abstract
Abstract: :
Purpose: We asked whether mRNAs encoding members of the triacylglycerol lipase family were expressed in the human lacrimal gland. Methods: Poly(A)+ RNA was isolated from male human lacrimal gland tissue. (Human lacrimal gland tissue was made available by Dr. John Ubels.) We synthesized cDNA and amplified the cDNA with degenerate PCR primers based on two highly conserved sequence motifs in the triacylglycerol lipase family: RITGLD(P/A) and D(I/F)(Y/F)PNGG. We subcloned and sequenced the 180 base pair PCR products. Results: We compared the nucleotide sequences of human lacrimal gland PCR products with those in GenBank data bases. We identified PCR fragments representing lipoprotein lipase (LPL; accession # NM_000237) and lipase H (LIPH; accession# NM_139348), each members of the triacylglycerol lipase family. LipH is also known as phosphatidic acid–selective phospholipase A1 (PA–PLA1), an enzyme that converts phosphatidic acid to 2–acyl lysophosphatidic acid (LPA), a lipid mediator. Conclusions: Human lacrimal gland expressed cDNAs encoding LPL and LIPH. The LIPH enzyme, and/or its product LPA, may be secreted in the tears.
Keywords: gene/expression • lacrimal gland