Project: Research project

Project Details


DESCRIPTION (Adapted from Applicant's Abstract): Progression of renal
disease is associated with the abnormal deposition of collagen IV and
other matrix macromolecules. Humoral and cellular factors that regulate
collagen IV synthesis in the normal and diseased kidney have not been
well defined. TGF- beta1 is a potent cicatricial mediator that markedly
stimulates fibrillar collagen (collagen I and collagen III) synthesis in
many cell systems. Recent studies have demonstrated that TGF-beta1 is
produced during experimental glomerulonephritis and may play a role in
both glomerular and interstitial accumulation of collagen IV during
disease progression.It is hypothesized that TGF-beta1 plays a dominant
role in the progression of renal injury to renal failure by stimulating
transcription of the collagen IV genes. The major objective of this
grant application is to determine the mechanism by which TGF-beta1
increases transcription of the collagen IV genes. TGF-beta1 mediated
induction of alpha1(IV) and alpha2(IV) collagen mRNA will be assessed
in cell derived from rat glomeruli, tubular epithelium, and interstitium.
Collagen IV gene transcription will be measured by nuclear run-on assays.
Since two levels of transcriptional regulation of collagen IV, transcript
initiation and transcript elongation have been identified, the role of
TGF- beta1 in stimulation of transcript initiation and elongation will
be characterized in NIH-3T3 cells, a readily manipulable cell line that
responds to TGF-beta1 with increases in alpha1(IV) and alpha2(IV)
collagen mRNA and collagen IV gene transcription. The alpha1(IV) and
alpha2(IV) collagen genes share a 130 base pair bidirectional promoter;
an enhancer element within the first intron of the alpha1(IV) gene is
necessary for tissue-specific expression of the collagen IV genes. The
role of these and other potential cis-acting factors in TGF-beta1
mediated induction of collagen IV transcription will be defined by
transfecting chimeric collagen IV promoter/enhancer gene constructs into
TGF-beta1 treated NIH-3T3 cells. Gel mobility shift assays and DNAse
I footprinting studies will be used to identify putative trans-acting
factors that interact with critical regulatory elements within the
collagen IV genes. Elucidation of the cis- and trans- acting factors
important in TGF-beta1 mediated induction of collagen IV gene
transcription may provide the basis for development of better strategies
for therapeutic interventions aimed at blocking the progression of renal
injury to end stage renal disease.
Effective start/end date7/1/936/30/98


  • Medicine(all)