Preeclampsia-associated reduction of cathepsin D activity in the umbilical cord.
BACKGROUND
Preeclampsia is accompanied by an increase of collagen contents in the umbilical cord (UC) arteries and in Wharton's jelly. Cathepsin D is one of the enzymes which participates in collagen degradation and activates precursor forms of collagenolytic metalloproteinases. It was decided to evaluate the activity of cathepsin D within umbilical cord arteries, veins and Wharton's jelly and its alterations in preeclampsia.


METHODS
Umbilical cord components were separated and submitted to homogenisation/extraction with 0.05 M Tris-HCl+0.2% Triton X-100, pH 7.5. Proteolytic activities of the extracts were studied with a use of cathepsin D-specific substrate. Western immunoblot technique was employed to detect this enzyme.


RESULTS
It was found that human umbilical cord tissues contain both active and inactive forms of cathepsin D. Preeclampsia is associated with a distinct increase in the amount of this enzyme in the umbilical cord, whereas its activity deeply decreased. Activation with trypsin augments cathepsin D activity in preeclamptic umbilical cord to the values observed in control arteries or even exceeds the control values (veins, Wharton's jelly).


CONCLUSIONS
Preeclampsia is associated with a reduction in the activity of cathepsin D in human umbilical cord. The low activity of cathepsin D may reduce collagen degradation and enhance its accumulation in the umbilical cord, especially in the arteries. Similar changes in other foetal blood vessels may result in an increase of vascular resistance and hypertension, which may persist after birth.
Galewska
Zofia
Z
Department of Medical Biochemistry, Medical Academy of Białystok, ul. Mickiewicza 2, 15-089 Białystok-1, Poland.
Bańkowski
Edward
E
Romanowicz
Lech
L
Gogiel
Tomasz
T
Wolańska
Małgorzata
M
Jaworski
Stefan
S
D000328:Adult; D015153:Blotting, Western; D002402:Cathepsin D / Q000097:blood*; D005260:Female; D006454:Hemoglobins / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D045726:Metalloproteases / Q000097:blood; D010447:Peptide Hydrolases / Q000032:analysis; D011225:Pre-Eclampsia / Q000378:metabolism*; D011247:Pregnancy; D013379:Substrate Specificity; D014470:Umbilical Cord / Q000378:metabolism*
D006454:Hemoglobins; D045726:Metalloproteases; D010447:Peptide Hydrolases; D002402:Cathepsin D