Matrix metalloproteinases, MMP-7 and MMP-26, in plasma and serum of control and preeclamptic umbilical cord blood.

OBJECTIVE: Our previous paper demonstrated that preeclampsia-associated accumulation of collagen and proteoglycans in the umbilical cord tissues is a result of increased biosynthesis and decreased degradation of these components. Metalloproteinases (MMPs) are enzymes engaged in degradation of collagen and protein cores of proteoglycans, including those which bind peptide growth factors. Some MMPs, among them matrilysins MMP-7 and MMP-26, participate in activation other members of the MMP family. STUDY DESIGN: Studies were performed on the umbilical cord blood taken from 10 control (healthy) newborns and 10 newborns of preeclamptic women. We used Western immunoblotting, immunoenzymatic assay (ELISA) and zymography techniques for detection of matrilysins. The results were submitted to Student's t-test and Mann-Whitney test. RESULTS: Umbilical cord blood plasma and serum of control and preeclamptic newborns contained MMP-7 and MMP-26. Both enzymes existed in the form of complexes with other extracellular matrix components and/or their tissue inhibitors in control and preeclamptic subjects. Free latent forms of both matrilysins were observed after the action of reducing agent. Furthermore, we found a distinct increase in the amount of MMP-26 in preeclamptic umbilical cord (UC) blood. No significant differences in MMP-7 content and activity in control and preeclamptic UC blood were observed. CONCLUSIONS: MMP-7 and MMP-26 could activate MMP-9 by cleavage of some sites in pro-MMP-9. Our results suggest that the high activity of MMP-9 participates in a proteolytic release of peptide growth factors from their complexes with extracellular matrix components, which facilitate their interaction with membrane receptors and stimulate cell division and extracellular matrix synthesis in these cells. It may be one of the mechanisms of extracellular matrix remodelling in the umbilical cord of preeclamptic newborns.

[Fibroblast growth factor gene expression in uterine leiomyomas]. / Ekspresja genu czynnika wzrostowego fibroblastów w miesniakach macicy.

OBJECTIVES: The aim of the study was the evaluation of acidic and basic FGF expression, as well as collagenolitic activity in human uterine leiomyomas at various stages of tumour growth. MATERIAL AND METHODS: Studies were performed on human myometrium and uterine leiomyomas of various weights (small: i.e. less than 10 g, and large: i.e. more than 100 g). The RT-PCR method was used to determine the acidic and basic FGF mRNA levels. The content of both FGF was evaluated by immunoenzymatic method (ELISA). The collagenolitic activity was detected by zymography. RESULTS: A distinct increase in the expression of aFGF, the amounts of both FGFs, and collagenolitic activity was observed during the tumour growth. CONCLUSIONS: Myometrium conversion into leiomyoma and an increase in its mass is accompanied by a significant increase in aFGF gene expression. The collagenolitic activity elevation favours a release of both FGF isoform from complexes with extracellular matrix components.

Gelatinase matrix metalloproteinase (MMP)-2 and MMP-9 of the umbilical cord blood in preeclampsia.

BACKGROUND: Preeclampsia is associated with accumulation of collagen and proteoglycans in the umbilical cord tissues as a result of increased biosynthesis and decreased degradation of these components. Matrix metalloproteinases (MMPs) are enzymes engaged in the degradation of collagen and the protein core structures of proteoglycans, including those which bind peptide growth factors. METHODS: We used Western immunoblots, immunoenzymatic assay (ELISA) and zymography techniques for the detection of gelatinases and their inhibitors. RESULTS: We found that both umbilical cord blood plasma and serum of controls and preeclamptic newborns contained MMP-2 and MMP-9, as well tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2. The umbilical cord plasma of preeclamptic subjects contained large amounts of MMP-9 in a form of complexes with other plasma components, and zymographic analysis demonstrated increased gelatinolytic activity at a position corresponding to MMP-9, compared to control samples. By contrast, MMP-2, TIMP-1 and TIMP-2 data showed no significant differences between preeclamptic and control samples. CONCLUSIONS: The high activity of MMP-9 in preeclamptic plasma suggests its participation in the proteolytic release of peptide growth factors from their complexes with other matrix components, with subsequent stimulation of cell division and matrix biosynthesis. We suggest this might represent one of the mechanisms for matrix remodeling in the umbilical cord of preeclamptic newborns.

TGF-beta binding in human Wharton's jelly.

Our previous study reported that TGF-beta may be isolated from human Wharton's jelly (WJ) in a form of soluble, high molecular complex(es). We decided to study the effect of extracellular matrix degradation and reduction of disulphide bridges reduction on the release of TGF-beta from WJ. The WJ prepared from the umbilical cords of newborns delivered at term by healthy mothers was homogenised and treated with hyaluronidase, collagenase, heparinase, chondroitinase and beta-mercaptoethanol, the resulting extracts were then submitted to TGF-beta immunoassay and SDS/PAGE followed by Western immunoblotting. The effect of metalloproteinase activation on TGF-beta was also studied. Pre-treatment of WJ homogenates with hyaluronidase or collagenase markedly increased the extractability of TGF-beta, but did not dissociate the complexes. In contrast, the action of beta-mercaptoethanol resulted in the release of free TGF-beta; but activation of metalloproteinases resulted in the disappearance of this factor. We conclude that TGF-beta1 is bound through disulphide bonds to an extracellular matrix component of WJ. The large amount of collagen fibrils and hyaluronate molecules which surround the cells scattered in WJ may prevent the access of extracting solution to TGF-beta causing a low extractability of this factor. Although hyaluronate and collagen do not bind TGF-beta directly, they may present a barrier that prevents the diffusion of TGF-beta in WJ and results in its concentration around the cells thereby facilitating its interaction with membrane receptors and subsequent stimulation of cell division and synthesis of extracellular matrix components.

Fatty acid composition of triacylglycerols from Wharton's jelly determined by high-performance liquid chromatography.

The improved method for HPLC determination of fatty acids was proposed. The chromatographic separation of p-bromophenacyl derivatives of fatty acids under a gradient elution was achieved at 40 degrees C with an RP-18 LiChroCART 5 column and organic mobile phase containing methanol, acetonitrile, water and TEAP buffer pH 5.6. The quantitative determination of those derivatives was performed at 254 nm. Preeclampsia, the most common pregnancy complication, did not affect triacylglycerol content in the umbilical cord Wharton's jelly in comparison to the control material. However, it changed the composition of fatty acids, bound to that lipid class. The method allows the determination of almost all fatty acids forming the investigated neutral lipid class, contained in a solid tissue sample. The use of TEAP buffer excluded precipitation and flow stoppage in the HPLC system. The method reduced time and costs and might be useful for all other lipid classes and different tissues.

Separation and Determination of Fatty Acids from Lipid Fractions by High-Performance Liquid Chromatography: Cholesterol Esters of Umbilical Cord Arteries.

Preeclampsia is accompanied by an extensive remodeling of the extracellular matrix of umbilical cord. It is associated with an increase in collagen content in the umbilical cord artery. Furthermore, preeclampsia distinctly reduces proteolytic and gelatinolytic activity, especially after activation with various agents.We decided to develop a method for separation and determination of fatty acids from different tissues by high-performance liquid chromatography. That method allowed us to determine cholesteryl ester composition and content in umbilical cord arteries. Studies were performed on the umbilical cord arteries taken from 10 newborns delivered by healthy mothers and 10 newborns delivered by mothers with preeclampsia. Cholesteryl esters were isolated by thin layer chromatography. Fatty acids were liberated by basic hydrolysis and analyzed by HPLC of their p-bromophenacyl derivatives using detection at 254 nm. It was found that saturated fatty acids were the main group of fatty acids incorporated to cholesteryl esters in all control and preeclamptic umbilical cord arteries. Preeclampsia caused a significant increase in cholesteryl ester content in the umbilical cord arteries. An increase of neutral lipid content in vessel walls of newborns delivered by mothers with preeclampsia may be one of the factors that evoke the initiation of hypertension in utero and its amplification throughout childhood and adult life. The described method reduces time and cost consumption and allows us to determine almost all fatty acids forming cholesteryl esters contained in the tissue sample.

FGF binding by extracellular matrix components of Wharton's jelly.

Our earlier paper has reported that Wharton's jelly is a reservoir of several peptide growth factors, including acidic and basic fibroblast growth factors (aFGF and bFGF, respectively). Both can be extracted by buffered salts solutions in the form of high molecular mass complexes, probably with a component(s) of the extracellular matrix. Both aFGF and bFGF from such extracts hardly penetrate 10% polyacrylamide gels during electrophoresis. Pre-treatment of Wharton's jelly with hyaluronidase slightly increased the extractability of aFGF, but did not affect the extractability of bFGF. In contrast, the pre-treatment of tissue homogenate with bacterial collagenase (2000 U/ml, 37 degrees C, 18 h) increased the extractability of bFGF. The presence of beta-mercaptoethanol in the extracting solutions increased the extractability of both FGFs, but did not release FGFs in their free form, despite reducing the molecular mass of the FGF-containing complexes. We conclude that both aFGF and bFGF are bound through disulphide bonds to a protein component of Wharton's jelly. We propose that ground substance composed mainly of collagen fibrils and hyaluronate molecules, which surrounds the cells of Wharton's jelly, prevents the access of the extracting solution to aFGF and bFGF. Although hyaluronate and collagen do not bind aFGF or bFGF directly, they may constitute a barrier which prevents the dispersion of FGFs in Wharton's jelly. Thus, the high concentration of FGFs around the cells of Wharton's jelly may facilitate the interaction of these factors with membrane receptors, thereby resulting in stimulation of cell division and differentiation, as well as of the synthesis of extracellular matrix components.

Pre-eclampsia-associated alterations in decorin, biglycan and versican of the umbilical cord vein wall.

OBJECTIVE: The role of proteoglycans in the rearrangement of the extracellular matrix of the umbilical cord vein wall in pre-eclampsia is not known. Decorin, biglycan and versican are the main proteoglycans of the umbilical cord vein wall. We decided to test whether the amounts of these proteoglycans alter in pre-eclampsia. STUDY DESIGN: Study was performed on the umbilical cord veins taken from 10 newborns delivered by healthy mothers (control group) and from 10 newborns delivered by mothers with pre-eclampsia. Proteoglycans were extracted in dissociative conditions, purified by Q-Sepharose anion exchange chromatography and lyophilised. Decorin, biglycan and versican were analysed by SDS-PAGE followed by Western blotting before and after treatment with chondroitinase ABC. The amounts of decorin, biglycan and versican core proteins were assessed by ELISA method. RESULTS: We found that both control and pre-eclamptic umbilical cord vein wall contained all the three proteoglycans. ELISA assay showed the amounts of the core proteins of decorin, biglycan and versican were distinctly higher in pre-eclamptic material in comparison to control vessel. Western blotting confirmed that the expression of all these proteoglycan core proteins increased in pre-eclampsia. They featured in the same electrophoretic mobility-45 and 47 kDa for decorin, 45 kDa for biglycan, and 300 and 320 kDa for versican. CONCLUSION: The content of decorin, biglycan and versican in the umbilical cord vein wall is elevated in pre-eclampsia in comparison to the corresponding control vessel. These alterations may affect the mechanical properties of this vessel and disturb foetal blood circulation.

The inhibitory effect of preeclamptic umbilical cord blood serum on matrix metalloproteinase-1 in arterial slices incubated in vitro.

BACKGROUND: Our previous studies demonstrated that preeclampsia is accompanied by significant alterations in the amounts of peptide growth factors in the umbilical cord serum. Some of these factors (especially IGF-1) are known as regulators of collagen metabolism. The umbilical cord arteries (UCAs) of newborns delivered by mothers with preeclampsia contain more than twice the amount of collagen in comparison to newborns delivered by healthy mothers. A significant role in collagen degradation is attributed to matrix metalloproteinase (MMP)-1 (collagenase 1) and tissue inhibitors of metalloproteinases (TIMPs). OBJECTIVE: To compare the effects of umbilical cord (UC) blood serum of control and preeclamptic newborns on the content and activity of MMP-1, TIMP-1 and TIMP-2 in UCA wall slices incubated in vitro. METHODS: Polyacrylamide gel electrophoresis (PAGE) followed by Western immunoblotting allowed to detect MMP-1 as well as TIMP-1 and TIMP-2. The amounts of MMP-1, TIMP-1 and TIMP-2 in UCA slices were measured by immunoenzymatic method (ELISA). MMP-1 activity in the arterial wall was measured using a collagenase-1-specific substrate. RESULTS: Western immunoblot analyses detected MMP-1, TIMP-1 and TIMP-2 in the incubation fluids and in extracts from the UCA wall. Both 43- and 55-kDa (a zymogen) bands of MMP-1 were visible. The control UC serum stimulated both the amount as well as actual and potential activities of MMP-1 in the arterial wall in a time-dependent manner. In contrast to controls, the preeclamptic serum did not exert such an effect. CONCLUSIONS: The small amount and low activity of MMP-1 accompanied by elevated amounts of TIMPs (especially TIMP-1) decelerate the degradation and enhance the accumulation of collagen in the preeclamptic UCA wall.

[Epidermal growth factor (EGF) in uterine leiomyoma during tumour growth]. / Czynnik wzrostu naskórka (EGF) w przebiegu wzrostu miesniaków macicy.

OBJECTIVES: Extracellular matrix is a place where various growth factors are bound and immobilised. It is expected that leiomyoma-associated remodelling of extracellular matrix in the uterus may be evoked by changes in the content of some growth factors. DESIGN: The amount and distribution of EGF in the normal myometrium and in the leiomyoma during various growth stages were investigated. MATERIAL AND METHODS: The assay of EGF was carried out with the use of ELISA commercial kit. SDS/polyacrylamide gel electrophoresis of tissue extracts followed by Western immunoblot was performed. RESULTS AND CONCLUSIONS: It was found that all investigated tissues contained endogenous EGE Extractability of EGF depended on type of extracting solvent. Only slight amount of EGF could be extracted by 1 M acetic acid. Much more EGF could be solubilized in 0.05M Tris/HCl, pH 7.6. Our results showed that EGF bound to the uterus (normal and leiomyoma) components of different molecular mass. It is of interest that some components of both, acidic and neutral extracts (myometrium and leiomyomas) were not able to bind exogenous 125I-labelled EGF.

Pre-eclampsia-associated alterations in Wharton's jelly proteoglycans.

Proteoglycans of Wharton's jelly contain mainly chondroitin/dermatan sulphate chains. The predominant proteoglycan is decorin (core proteins of 45 and 47 kDa), although the core proteins of biglycan (45 kDa), versican (260 kDa) and of other proteoglycans (90, 110, 220 kDa) were also detected (Gogiel et al., 2003). The aim of the present study was to compare the proteoglycan composition of Wharton's jelly of newborns delivered by healthy mothers and those with pre-eclampsia. Proteoglycans from pre-eclamptic Wharton's jelly had a higher sulphated glycosaminoglycan/protein ratio than those of normal tissue. Pre-eclampsia is associated with a lower level of all proteoglycan core proteins, especially those of higher molecular mass (such as versican), although the same set of core proteins were found in normal and pre-eclamptic Wharton's jelly. The alterations in the proteoglycan composition of Wharton's jelly may affect the mechanical properties of the umbilical cord and, in the case of pre-eclampsia, disturb foetal blood circulation.

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. MATERIALS AND 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.

Decreased expression of the insulin-like growth factor-I-binding protein-1 (IGFBP-1) phosphoisoform in pre-eclamptic Wharton's jelly and its role in the regulation of collagen biosynthesis.

Insulin-like growth factor-I (IGF-I) is known as an important stimulator of collagen and glycosaminoglycans (GAGs) biosynthesis in tissues. IGF-I activity is under control of IGF-I-binding proteins (IGFBPs) with different IGF-I-binding affinity. IGFBP-1 is known as an inhibitor of IGF-dependent functions. Some IGFBPs (e.g., IGFBP-1) may undergo phosphorylation that dramatically increases IGFBP affinity for IGF. Wharton's jelly represents a reservoir of IGF-I and its binding proteins (BPs). Pre-eclampsia, the most common, pregnancy-associated pathological syndrome, contributes to a significant decrease in IGF-I and IGFBP-1 content in Wharton's jelly, although it does not affect collagen content in this tissue. In the present study we show that control Wharton's jelly contains phosphorylated forms of IGFBP-1 that are dramatically dephosphorylated during pre-eclampsia. A dramatic decrease in IGF-I binding to immunoprecipitated IGFBP-1 from pre-eclamptic Wharton's jelly compared to the control was observed. Western immunoblot analysis with anti-phosphothreonine antibodies for immunoprecipitated IGFBP-1 from control and pre-eclamptic Wharton's jelly revealed that both tissues contain phosphorylated forms of IGFBP-1. However, a distinct decrease in the expression of phosphorylated IGFBP-1 from pre-eclamptic Wharton's jelly was observed. The functional significance of the phenomenon was found in cultured fibroblasts treated with IGFBP isolated from Wharton's jelly extracts. A significant decrease in collagen biosynthesis was found in the cells treated with IGFBP of control Wharton's jelly, while in the presence of IGFBP from pre-eclamptic Wharton's jelly, the rate of collagen biosynthesis was similar to that in the control cells. The result was corroborated by data showing increase in expression of IGF-I receptor and phosphorylated MAP kinases (ERK1 and ERK2) in fibroblasts cultured in the presence of IGFBP from pre-eclamptic Wharton's jelly, compared to control. The data suggest that the decrease in phosphorylated IGFBP-1 in pre-eclamptic Wharton's jelly may decrease IGF-I-binding affinity for IGF and increase the bioavailability of IGF-I for receptor interaction. This mechanism may facilitate IGF-I-dependent stimulation of fibroblasts to produce extracellular matrix (ECM) components even at a low IGF-I tissue level. Therefore, IGFBP-1 phosphoisoforms in Wharton's jelly may play an important role in the regulation of IGF-I-dependent functions during pre-eclampsia.

Matrix metalloproteinases of human leiomyoma in various stages of tumor growth.

The amounts and activities of matrix metalloproteinases (MMPs) were studied in human myometrium and uterine leiomyomas in various stages of growth. It was found that both myometrium and the investigated tumors contain collagenolytic enzymes. MMP-1, MMP-2, MMP-3 and MMP-9 were found. Gelatinase A (MMP-2) is the most abundant. In control myometrium only 10% of this enzyme exists in an active form, whereas in tumors, especially in large ones, the values reach 30%. It is suggested that the high activity of MMP-2 is responsible for remodelling of extracellular matrix in the growing tumors.

[Extracellular matrix of the umbilical cord vein in EPH gestosis and fibroblast growth factor]. / Skladniki macierzy pozakomórkowej zyly pepowinowej w przebiegu gestozy EPH a czynnik wzrostu fibroblastów (FGF).

It was found in our previous studies that EPH gestosis is accompanied by an extensive remodeling of the extracellular matrix of the umbilical cord. Studies were performed on the umbilical cord veins of 10 control and 10 newborns delivered by mothers with EPH gestosis. It was decided to determine umbilical cord vein ability to bind of labeled (125J)-basic fibroblast growth factor (bFGF), and FGF content by Western immunoblot and ELISA methods. Our experiments indicated that the extracts of umbilical cord vein contain endogenous bFGF and several soluble FGF-binding compounds of different molecular weight. It is of interest that EPH gestosis is associated with a decrease in bFGF content. It seems be possible that the decrease of bFGF amount may be one of the factors, which constrain the biosynthesis of collagen in EPH gestosis umbilical cord vein wall.

The activities of some glycosaminoglycan-degrading enzymes in uterine leiomyomas.

The activities of some glycosaminoglycan-degrading enzymes in uterine leiomyomas. Both normal human myometrium and uterine leiomyoma contain several glycosaminoglycans (GAGs). In contrast to many normal and tumour tissues the amount of hyaluronic acid (HA) is very low and the proportional amount of sulphated glycosaminoglycans is distinctly higher. We compared the activity of GAG-degrading enzymes in normal myometrium and in uterine leiomyomas. Growth of uterine leiomyomas results in significant reduction in the activities of neutral endoglycosidases degrading most of the sulphated glycosaminoglycans. The activities of acid endoglycosidases also decreased (with the exception of chondroitin-6-sulphate). Thus, the differentiated activity of glycosidases degrading glycosaminoglycans can be a factor modifying the quantity of GAGs.

Pre-eclampsia (EPH-gestosis)-induced decrease of MMP-s content in the umbilical cord artery.

BACKGROUND: It was found in our previous paper that pre-eclampsia-associated accumulation of collagen in the umbilical cord artery (UCA) is a result of increased biosynthesis and decreased degradation of this protein. It is known that the activity of collagenolytic enzymes is a main factor regulating collagen degradation rate in various tissues. METHODS: For this reason it was decided to evaluate the effect of pre-eclampsia on the content and activity of metalloproteinases by immunoenzymatic method (ELISA), zymographic technique and with the use of specific substrates. RESULTS: A low amount of MMP-1 (collagenase 1), MMP-9 (gelatinase B) and MMP-3 (stromelysin 1) was detected in the extracts from the wall of the umbilical cord artery. MMP-2 (gelatinase A) is the main collagenolytic enzyme in UCA wall (both latent and active form). Pre-eclampsia is associated with a distinct reduction in those metalloproteinases content in comparison to control UCAs. It can be concluded from zymography that MMP-2 (gelatinase A) of the umbilical cord artery forms an inactive complex with a tissue inhibitor of metalloproteinases (TIMP). Such a complex dissociates under the action of p-aminophenylmercuric acetate (APMA) or sodium dodecyl sulphate. CONCLUSIONS: The decrease of metalloproteinases content and activity in the umbilical cord artery may be a factor that reduces the breakdown of collagen in the arterial wall and promotes the accumulation of this protein. The accumulation of collagen with simultaneous reduction in elastin content in the UCA may be the factor that reduces the elasticity of arterial wall and decreases the blood flow in the fetus of women with pre-eclampsia.

Proteoglycans of Wharton's jelly.

Wharton's jelly (WJ) is a myxomatous substance surrounding the blood vessels of the umbilical cord. Proteoglycans (PGs) of Wharton's jelly have not been studied to date therefore it was decided to explore proteoglycan composition of this tissue. Proteoglycans were subjected to dissociative extraction with 4M guanidine hydrochloride containing Triton X-100 and protease inhibitors, purified by Q-Sepharose anion-exchange chromatography and lyophilised. They were analysed by gel filtration and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) before and after treatment with chondroitinase ABC. It was found that 1g of Wharton's jelly contains 2.43+/-0.63mg (n=10) of sulphated glycosaminoglycans (GAGs), reflecting the presence of proteoglycans. The proteoglycans were mainly substituted with chondroitin/dermatan sulphate (DS) chains. The predominant proteoglycan fraction included small proteoglycans with core proteins of 45 and 47kD, immunologically related to decorin (45 and 47kD) and biglycan (45kD). The expression of decorin core proteins was much higher than that of biglycan. Larger proteoglycans (core proteins of 90, 110, 220 and 260kD) were found in lower amounts. The most abundant of them (core protein of 260kD) was immunologically related to versican. Perlecan was not identified in Wharton's jelly. The study shows that Wharton's jelly contains mainly small chondroitin/dermatan sulphate proteoglycans, with decorin strongly predominating over biglycan. We suggest that an intensive expression of decorin is associated with very high content of its ligand, collagen.

The effect of pre-eclamptic umbilical cord serum on fibroblast division in culture.

Edema, proteinuria, hypertension (EPH-gestosis), most commonly termed as pre-eclampsia, is the most common pregnancy-associated pathological syndrome. It is accompanied by a thorough remodelling of extracellular matrix in the umbilical cord tissues. It is commonly known that the presence of serum in culture medium strongly stimulates many functions of cells cultured in vitro. It was decided to check how the pre-eclamptic serum affects the fibroblast division in culture. Ki-67 is a protein present in proliferating cells and can be detected during all phases of the cell cycle (G1, S, G2/M) but not in resting (G0) cells. PCNA (proliferating cell nuclear antigen) is an intranuclear polypeptide whose synthesis rate is at its maximum during the S-phase of the cell cycle. The expression of Ki-67 and PCNA was measured by immunocytochemical methods and biosynthesis of DNA was evaluated by [14C]-thymidine incorporation. The activity of pre-eclamptic umbilical cord serum (UC-serum) was found to be distinctly lower in comparison to control one. The expression of Ki and PCNA in fibroblast cultures treated with pre-eclamptic serum was also distinctly lower. Also the incorporation of [14C]-thymidine to DNA was lower than in the cultures treated with control UC-serum. It may by concluded that pre-eclampsia reduces the mitogenic activity of the umbilical cord serum.