Does vascular endothelial growth factor participate in uterine myoma growth stimulation?

Objective: Peptide growth factors play a role in the rebuilding of extracellular matrix in the course of leiomyoma growth, and exert a regulative effect on the cell only when they bind with a specific membrane receptor and transmit a signal into the cell. A high content of certain peptide growth factors and their receptors in leiomyoma suggests that in the course of the tumour growth hyperstimulation of cells takes place. A combined action of various peptide growth factors causes an amplification of signal paths in cells, inducing gene expression of proteins responsible for cell division and changes of metabolism.

Identification and localization of S100A6 in human umbilical cord.

S100A6, a calcium-binding protein also known as calcyclin, was detected in human umbilical cord by immunoblotting. Immunohistochemical studies showed an intensive reaction for S100A6 in the walls of vessels and Wharton's jelly. In the latter, S100A6 was found not only in the myofibroblasts but also in the ECM (extracellular matrix) surrounding these cells.

Glucose deficiency reduces collagen synthesis in breast cancer MCF7 cells.

We decided to study the effect of glucose deprivation on collagen metabolism in MCF7 cells. The incorporation of [3H]-proline into collagenase-sensitive and hydroxyproline-containing proteins was used as an index of collagen synthesis, whereas pulse-chase technique was employed to evaluate the degradation of newly synthesized proteins. The MCF7 cells incubated in high glucose medium synthesized detectable amounts of collagenous proteins.

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.

Altered sphingolipid composition in Wharton's jelly of pre-eclamptic newborns.

Objectives: Wharton's jelly is a myxomatous substance surrounding the umbilical cord (UC) vessels to protect them against extension, bending, twisting and compression. Pre-eclampsia (hypertension, oedema, proteinuria) is the most common pregnancy-associated pathological syndrome. It is accompanied by significant alterations in UC composition.

Glucose deficiency inhibits glycosaminoglycans synthesis in fibroblast cultures.

We decided to study the effect of glucose deprivation on glycosaminoglycan (GAG) synthesis and degradation in fibroblast cultures, vitality of these cells and a correlation of these processes with the expression of oxygen/glucose-regulated proteins (ORP150/GRP170). The incorporation of [(3)H]-glucosamine into both newly synthesised hyaluronic acid and sulphated GAGs and [(35)S]-sulphate into GAGs was used as an index of glycosaminoglycan synthesis. Quantitative evaluation of newly synthesised GAGs degradation was determined by pulse-chase experiments.

Sphingolipids of human umbilical cord vein and their alteration in preeclampsia.

Preeclampsia is the most common pregnancy-associated pathological syndrome. It is accompanied by the accumulation of free fatty acids, acylglycerols and cholesterol esters in the umbilical cord vein (UCV). We evaluate the sphingolipid composition of UCV and its alteration in preeclampsia.

Lipid compounds of human Wharton's jelly and their alterations in preeclampsia.

Wharton's jelly is a myxomatous substance which surrounds the umbilical cord vessels protecting them against extension, bending, twisting and compression. Very low number of cells in this tissue produce high amounts of extracellular matrix; collagen, hyaluronate and proteoglycans which bind large quantities of peptide growth factors (PGFs). Preeclampsia (the most common pregnancy-associated syndrome) is accompanied by a significant reduction in hyaluronate and a concomitant increase in sulphated glycosaminoglycans/proteoglycans content in Wharton's jelly.

Preeclampsia-associated alterations in sphingolipid composition of the umbilical cord artery.

Objectives: Preeclampsia, the most common pregnancy-associated pathological syndrome, is accompanied by significant remodelling of the extracellular matrix and alteration in lipid composition of the umbilical cord artery (UCA).

Design And Methods: We evaluate the sphingolipid composition of UCA and its alteration in preeclampsia. Thin layer chromatography, solid-phase extraction and high-performance liquid chromatography were employed for these analyses.

The effect of glucose deprivation on collagen synthesis in fibroblast cultures.

It was decided to study the effect of glucose deprivation on collagen synthesis and degradation in fibroblast cultures and a correlation of these processes with the expression of oxygen/glucose regulated proteins (ORP150/GRP170). The incorporation of radiolabeled proline into collagenase-sensitive and hydroxyproline-containing proteins was used as an index of collagen synthesis, whereas pulse-chase technique was employed to evaluate the degradation of newly synthesised proteins. We demonstrated that fibroblasts incubated in high-glucose medium synthesised detectable amounts of collagenous proteins.

Lipid compounds of the umbilical cord artery and their alterations in preeclampsia.

The lipid composition of arterial walls changes during development, ageing and pathological processes. Preeclampsia is the most common pregnancy-associated pathological syndrome. It is accompanied by significant remodelling of the extracellular matrix, both in the umbilical cord vessels and in the surrounding Wharton's jelly.

Lipid compounds of the umbilical cord vein and their alterations in preeclampsia.

The lipid composition of vascular walls changes during development, ageing and pathological processes. Preeclampsia is the most common pregnancy-associated pathological syndrome. It is accompanied by significant remodelling of the extracellular matrix, both in the umbilical cord vessels and in the surrounding Wharton's jelly.

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.

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.

Glucose-depleted medium reduces the collagen content of human skin fibroblast cultures.

Glucose deprivation appeared to be a factor which induces oxygen regulated protein (ORP) 150 expression in the human skin fibroblasts cultures. Whereas glucose deprivation resulted in a slight (statistically insignificant) decrease of protein content in these cultures, a marked decrease of collagen content was observed, resulting in a distinct reduction of hydroxyproline: protein ratio. Furthermore, the appearance of ORP150 in glucose-deprived cultures coexisted with an increase of gelatinolytic activity and slight reduction in the expression of insulin-like growth factor-I (IGF-I) receptor.

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.

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.

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.

Transforming growth factor beta and platelet-derived growth factor in human myometrium and in uterine leiomyomas at various stages of tumour growth.

Objective: Some authors suggest that growth factors are intermediate regulatory elements through which the ovarian hormones exert their growth-stimulatory effects on uterine leiomyomas.

Study Design: It was decided to compare the amounts of transforming growth factor beta (TGF-beta) and platelet-derived growth factor (PDGF) in myometrium and in uterine leiomyomas of various weights (small: less than 10 g and large: more than 100 g). The tissues were homogenised and extracted with 1M acetic acid or with 0.

The effect of hypoxia on the expression of 150 kDa oxygen-regulated protein (ORP 150) in HeLa cells.

Correct protein folding is an important factor, for the translocation of newly synthesised proteins to specific subcellular compartments, extracellular matrix or to biological fluids. This process is regulated by a group of specific proteins, referred to as chaperones. Many stress conditions, such as oxygen or glucose deprivation, slow down the folding process and cause accumulation of unfolded/misfolded proteins in the cell.

Glucose effect on the expression of 150 kDa oxygen-regulated protein in HeLa cells.

Chaperones assist in the correct folding of newly synthesised proteins in the endoplasmic reticulum (ER) of cells, this being essential for the translocation of protein molecules to specific subcellular compartments, extracellular matrix or to biological fluids. The biosynthesis of some ER chaperones is regulated by glucose. They are named "glucose-regulated proteins" (GRPs).

An accumulation of insulin-like growth factor I (IGF-I) in human myometrium and uterine leiomyomas in various stages of tumour growth.

It is commonly thought that uterine leiomyomas result from hyperstimulation of myometrium by ovarian hormones. Some observations suggest that cytokines and growth factors are intermediate elements through which the ovarian hormones may exert their growth-stimulatory effects on leiomyomas. Human myometrium and uterine leiomyomas of various weights were homogenised and extracted with 1 M acetic acid or with 0.

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.

Fasting-induced inhibition of collagen biosynthesis in rat skin. A possible role for phosphoenolpyruvate in this process.

Fasting is accompanied by a decrease in collagen biosynthesis. The mechanism of this phenomenon involves inhibition of prolidase activity, an enzyme that plays a key role in upregulation of collagen metabolism. The mechanism of fasting-induced inhibition of prolidase activity is not known.

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.