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Biomedical subjects

Lubna Nasir

Publications and source records attributed to Lubna Nasir.

2 recordsLinked to original sources

The cloning and functional analysis of canine matrix metalloproteinase-13 gene promoter.

A fragment of the 5' untranslated region corresponding to the canine matrix metalloproteinase-13 (MMP-13), collagenase-3 gene promoter has been isolated and characterized in rat cardiocytes to investigate the role of MMP-13 in cardiac disease. The promoter fragment (1.5 kb) demonstrated regions of sequence homology with the collagenase gene promoter sequences already determined for other species. Conserved regions were identified and shown to correlate with DNA binding motifs including AP-1 sites, a nuclear factor (NF) B-like binding domain, GATA and Nkx2.5 sites. A consensus TATA box was identified and shown to direct transcription initiation approximately 27 bp upstream of the translation start site. The canine MMP-13 promoter fragment was sufficient to drive basal expression of a luciferase reporter gene in both Madin Darby canine kidney cells (MDCK) and primary rat cardiocytes. The activity of the promoter fragment could be significantly increased by the treatment of transfected primary rat cardiocytes with interleukin-1 (IL-1) and basic fibroblastic growth factor (bFGF), with some induction also observed with tumour necrosis factor (TNF). The canine MMP-13 promoter activity has also been compared to the basal and induced activity of the canine MMP-9, gelatinase B promoter in these cell types.

5' Flanking Region↗

Telomere lengths in dogs decrease with increasing donor age.

In vitro and in vivo studies of human tissues have demonstrated telomeric attrition with age and have linked this attrition to cellular senescence and aging. Telomere studies in canine subjects have not thus far consistently uncovered the same pattern of telomere attrition that would be expected because of the end replication problem. In this report we describe the investigation of telomere lengths in a broad age range of dogs from three different breeds: the Labrador Retriever, Miniature Schnauzer and Beagle. Peripheral blood mononuclear cell-derived DNA samples were subjected to terminal restriction fragment (TRF) analysis and demonstrated a range of mean TRFs from 9.7 to 22.3 kbp. Telomeric attrition tended to be associated with increasing donor age (P = 0.06). Interbreed differences in mean TRF values were also noted (P = 0.006). These results warrant further investigation of possible interbreed differences, given that shorter telomeres may contribute to differing life expectancy between breeds.

Aging↗