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Gail L Matters

Publications and source records attributed to Gail L Matters.

4 recordsLinked to original sources

Meprin beta metalloprotease gene polymorphisms associated with diabetic nephropathy in the Pima Indians.

There is evidence that susceptibility to diabetic nephropathy has a significant genetic component. This investigation tested the hypothesis that variations in the structural or regulatory regions of the MEP1B gene are related to susceptibility to diabetic nephropathy in the Pima Indian population. The structure of the human MEP1B gene on chromosome 18 was determined by polymerase chain reaction (PCR) amplification. Samples from 154 diabetic individuals were analyzed for polymorphisms. These individuals belonged to 65 sibships with at least one sibling pair discordant for diabetic nephropathy. Approximately half of the individuals had diabetic nephropathy. Of the 154 samples, there were 91 discordant sibling pairs. Sequencing revealed 19 single nucleotide polymorphisms (SNPs) in the MEP1B gene. SNPs 1-5 were in the 5' region upstream of the start site for transcription; SNPs 6, 7, 9, 11-15, 17, and 19 were within introns; SNPs 8, 10, 16, and 18 were in exons 4, 9, 12, and 14. SNP 18 was the only one that results in an amino acid change (proline to leucine in the cytoplasmic tail). No overall associations were found for individual SNPs. Within-family association tests found significant results for SNPs 1, 3, 4, 5, 6, 9, 11, 18, and 19 such that the more common allele was more frequently observed in those with nephropathy than in their unaffected siblings. The present study demonstrates significant within-family association for SNPs in MEP1B gene with diabetic nephropathy. These results could be explained by functional effects of one or more of these SNPs or by linkage disequilibrium with a nearby functional locus.

DNA Primers↗

Meprin metalloprotease expression and regulation in kidney, intestine, urinary tract infections and cancer.

Meprins are unique plasma membrane and secreted metalloproteinases that are highly regulated at the transcriptional and post-translational levels. Meprin alpha and beta subunits are abundantly expressed in kidney and intestinal epithelial cells, are secreted into the urinary tract and intestinal lumen, and are found in leukocytes and cancer cells under certain conditions. Their location and proteolytic activities indicate functions at the interface of the host and the external environment, and in trafficking of macrophages and metastases of cancer cells. These proteases can be detrimental when there is tissue damage or disruption, as in acute renal injury or intestinal inflammation, and there is evidence they are involved in movement of leukocytes and cancer cells to sites of infection or in metastasis, respectively.

Animals↗

Inhibitors of polyamine biosynthesis decrease the expression of the metalloproteases meprin alpha and MMP-7 in hormone-independent human breast cancer cells.

Inhibition of ornithine decarboxylase (ODC), a key enzyme in polyamine biosynthesis, by the irreversible inhibitor alpha-difluoromethylornithine (DFMO) has been shown to decrease the invasiveness of metastatic human breast cancer cell lines. However, the mechanism by which DFMO acts to reduce invasiveness is unclear. Using the human breast cancer cell line MDA-MB-435, the effect of DFMO on metalloprotease gene expression was investigated. DFMO treatment decreases the expression of the metalloprotease meprin alpha, while concurrent treatment with DFMO and the polyamine putrescine partially restored meprin alpha expression levels. Expression of MMP-7 mRNA was reduced by DFMO, while MMPs-1, -2, -3, -14, and meprin beta were unaffected. Treatment of cells with a second inhibitor of polyamine biosynthesis, the S-adenosylmethionine decarboxylase (SAMDC) inhibitor SAM486A, also resulted in a dosage dependent decrease in meprin alpha and MMP-7 mRNA. In addition, DFMO treatment decreased meprin alpha at the protein level by 2 days of treatment, and MMP-7 protein levels at 4 and 6 days. Previous studies have shown that DFMO treatment increases ERK phosphorylation and signaling through the MAP kinase pathway. The decrease in meprin alpha expression was reversed with the MEK inhibitor PD98059, demonstrating that MAP kinase signaling mediates the effect of DFMO and SAM486A. MDA-MB-435 cells treated with the meprin alpha inhibitor actinonin (5 nM) were less invasive in vitro, indicating that meprin alpha is mechanistically involved in invasion. The decrease in meprin alpha expression in DFMO and SAM486A-treated cells indicates a means by which these compounds can decrease the invasiveness of metastatic breast cancer cells.

Amidines↗