Studies of the biochemical basis of steroid sulphatase deficiency: preliminary evidence suggesting a defect in membrane-enzyme structure

Embedded Immunodetection System for Fecal Occult Blood

In this paper, a rapid test system with high sensitivity, linearity, and stability is presented for fecal occult blood (FOB) detection. The coloration results of the immune response are used as the basis for the determination of the detection target in combination with an immunochromatographic strip. The rapid test system can be used to detect and calculate the concentration of the sample, so detection of the immune coloration response is more accurate in a quantitative analysis. The system is composed of both hardware and software. The programs used for the analysis and programmed by Python include the main program, polarization calibration, QR Code decoding, Bluetooth transmission, and image processing. After verification of each part of the system, it was found that the rapid test system successfully detects from 0 ng/mL to 400 ng/mL of FOB with coefficients of variation (CV) below 3.7% and 1000 ng/mL with a CV only at 7.41%.

Decrease in Sphingomyelin (d18:1/16:0) in Stem Villi and Phosphatidylcholine (16:0/20:4) in Terminal Villi of Human Term Placentas with Pathohistological Maternal Malperfusion

Placental villi play pivotal roles in feto-maternal transportation and phospholipids constitute a major part of the villous membrane. We have been developing and optimizing an imaging system based on a matrix-assisted laser desorption/ionization (MALDI)-based mass spectrometer, which provides clear two-dimensional molecular distribution patterns using highly sensitive mass spectrometry from mixtures of ions generated on tissue surfaces. We recently applied this technology to normal human uncomplicated term placentas and detected the specific distribution of sphingomyelin (SM) (d18:1/16:0) in stem villi and phosphatidylcholine (PC) (16:0/20:4) in terminal villi. In the present study, we applied this technology to nine placentas with maternal or fetal complications, and determined whether a relationship existed between these specific distribution patterns of phospholipid molecules and the six representative pathological findings of placentas, i.e., villitis of unknown etiology (VUE), thrombus, atherosis, chorioamnionitis (CAM), immature terminal villi, and multiple branched terminal villi. In two placentas with the first and second largest total number of positive pathological findings, i.e., five and three positive findings, the specific distribution of SM (d18:1/16:0) in stem villi and PC (16:0/20:4) in terminal villi disappeared. The common pathological findings in these two placentas were atherosis, immature terminal villi, and multiple branched terminal villi, suggesting the possible involvement of the underperfusion of maternal blood into the intervillous space. On the other hand, the number of pathological findings were two or less in the seven other placentas, in which no specific relationships were observed between the differential expression patterns of these two phospholipids in stem and terminal villi and the pathological findings of the placentas; however, the specific distribution pattern of SM (d18:1/16:0) in stem villi disappeared in four placentas, while that of PC (16:0/20:4) in terminal villi was preserved. These results suggested that the absence of the specific distribution of PC (16:0/20:4) in terminal villi, possibly in combination with the absence of SM (d18:1/16:0) in stem villi, was linked to placental morphological changes in response to maternal underperfusion of the placenta.

Optimization of an optical inspection system based on the Taguchi method for quantitative analysis of point-of-care testing

This study presents an optical inspection system for detecting a commercial point-of-care testing product and a new detection model covering from qualitative to quantitative analysis. Human chorionic gonadotropin (hCG) strips (cut-off value of the hCG commercial product is 25 mIU/mL) were the detection target in our study. We used a complementary metal-oxide semiconductor (CMOS) sensor to detect the colors of the test line and control line in the specific strips and to reduce the observation errors by the naked eye. To achieve better linearity between the grayscale and the concentration, and to decrease the standard deviation (increase the signal to noise ratio, S/N), the Taguchi method was used to find the optimal parameters for the optical inspection system. The pregnancy test used the principles of the lateral flow immunoassay, and the colors of the test and control line were caused by the gold nanoparticles. Because of the sandwich immunoassay model, the color of the gold nanoparticles in the test line was darkened by increasing the hCG concentration. As the results reveal, the S/N increased from 43.48 dB to 53.38 dB, and the hCG concentration detection increased from 6.25 to 50 mIU/mL with a standard deviation of less than 10%. With the optimal parameters to decrease the detection limit and to increase the linearity determined by the Taguchi method, the optical inspection system can be applied to various commercial rapid tests for the detection of ketamine, troponin I, and fatty acid binding protein (FABP).

Cholesterol sulphate sulphohydrolase of human placenta lysosomal membrane

In this paper we report that the activity of cholesterol sulphate sulphohydrolase (CHS-ase) is associated with the lysosomal membranes. The procedure of purification of CHS-ase from human placenta lysosomes was elaborated. The purified enzyme is highly specific to cholesterol sulphate (specific activity 2126.60+/-940.90 nmol min(-1) mg protein(-1)) and acts optimally at pH 3.4. The K(M) value for the hydrolysis of cholesterol sulphate is 3.6+/-0.95 x 10(-5)mol/l. The isoelectric point (pI) has the value 5.7, molecular weight estimated by SDS-PAGE electrophoresis is 38 kDa. The described enzyme may be involved in a regulation of cholesterol and cholesterol sulphate levels in the lysosomal membrane.

Dehydroepiandrosterone sulphate sulphohydrolase [correction of sulphoydrolase] from human placenta microsomes--properties of the purified enzyme

A form of steroid sulphate sulphohydrolase (EC 3.1.6.2) hydrolysing the dehydroepiandrosterone sulphate (DHEAS-ase) was purified from human placenta microsomes. During the purification procedure the DHEAS-ase was separated from the oestrone sulphate sulphohydrolase (OS-ase). The purified DHEAS-ase revealed specific activity of 1520 nmolxmin-1xmgprotein-1 and exhibited optimal activity at pH 8.4. The Km value was established to be 3.3+/-0.07x10(-5) M. The pI value was around 8.7. The molecular weight estimated by gel filtration was 7.4 kDa. The purified DHEAS-ase was not sensitive to the common sulphohydrolase inhibitors, such as phosphate, sulphate and sulphide ions, but was inhibited by several phosphohydrolase inhibitors (ammonium molybdate, vanadium oxide(V), zinc acetate). Steroids effected inhibition or activation of the purified enzyme. The data concerning substances reacting with -SH groups suggest that in the physiological conditions DHEAS-ase is controlled by the redox status of the cell.

Uptake of dehydroepiandrosterone-3-sulfate by isolated trophoblasts from human term placenta, JEG-3, BeWo, Jar, BHK cells, and BHK cells transfected with human sterylsulfatase-cDNA

The human placenta lacks the enzyme 17alpha-hydroxylase/17-20-lyase, and is thus unable to convert cholesterol into estrogens. Therefore estrogen synthesis of trophoblast cells depends on the supply of precursors such as dehydroepiandrosterone-3-sulfate (DHEA-S) and 16alpha-hydroxy-dehydroepiandrosterone-3-sulfate by maternal and fetal blood. To investigate the cellular internalisation of these anionic hydrophilic precursors, the uptake of [(3)H]-/[(35)S]-DHEA-S and [(3)H]-taurocholate by isolated cytotrophoblasts, cells of choriocarcinoma cell lines (JEG-3, BeWo, Jar), BHK and BHK cells transfected with human sterylsulfatase-cDNA (BHK-STS cells) was studied. Furthermore, the activity of sterylsulfatase of these cells in suspension and in corresponding cell homogenate was measured. During the first 5 min of incubation with [(3)H]-DHEA-S or [(35)S]-DHEA-S, radioactivity of cytotrophoblasts increased significantly, while radioactivity of JEG-3, Jar, BHK and BHK-STS cells did not increase. Radioactivity of BeWo cells increased slightly. For all cell types, there was no significant difference for uptake of either substrate. During incubation with [(3)H]-taurocholate, radioactivity of cytotrophoblasts did not increase. Sterylsulfatase activity of cytotrophoblast homogenate was significantly lower than that of cytotrophoblast suspension. Sterylsulfatase activity of BHK-STS, JEG-3 or BeWo cell homogenate was significantly higher than that of the corresponding cell suspension. In BHK and Jar cells sterylsulfatase activity was not detectable. Cytotrophoblasts take up DHEA-S without prior hydrolysis. BHK, BHK-STS, JEG-3, and Jar cells do not take up and BeWo cells slowly take up DHEA-S. In cytotrophoblasts extracellular DHEA-S rapidly gains access to intracellular sterylsulfatase, while in choriocarcinoma and BHK-STS cells access of DHEA-S to sterylsulfatase is limited. Our results indicate, that uptake by cytotrophoblasts is mediated by a carrier which is not expressed in choriocarcinoma or BHK cells and which is different from the known taurocholate-transporting organic anion transporting polypetides.

Murine steroid sulfatase (mSTS): purification, characterization and measurement by ELISA

The murine steroid sulfatase (mSTS) is a microsomal enzyme, important in steroid metabolism. In the mouse, the gene encoding mSTS is pseudoautosomal and thus escapes X-inactivation. We have purified steroid sulfatase approximately 30-fold from mouse liver microsomes and its properties have been investigated. The major steps in the purification procedure included solubilization with Triton X-100, gel filtration chromatography, DEAE-Sephadex chromatography and HPLC gel filtration chromatography. The purified sulfatase showed a relative molecular weight of 128 kDa on HPLC gel filtration, whereas the enzyme migrated as two bands of 60 and 68 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric point of steroid sulfatase was estimated to be 6.2 by column chromatofocusing. Polyclonal antibodies to the purified protein were prepared. An Enzyme Linked Immunosorbent Assay (ELISA) was developed using purified monospecific anti-mSTS antibodies labelled with peroxidase. The standard criteria of precision and reproducibility were satisfied. The assay was applicable to routine determination of mSTS samples in research laboratories. Differences in mSTS liver concentrations were used to identify putative alleles for the mSTS gene (Sts). Results in ELISA confirmed the polymorphism previously demonstrated for an enzymatic mSTS activity assay in two inbred mouse strains.

Enzymatic diagnosis of steroid sulfatase deficiency by high performance liquid chromatography

We established a reversed phase high performance liquid chromatographic (HPLC) method of assaying lymphocyte steroid sulfatase activity using estrone sulfate as the substrate. Application of this method for diagnosis of 8 patients allowed us to clearly distinguish the patients from the normal controls. This method is simpler and less expensive than the method previously reported, since neither radioisotope labeled substrates nor radioisotope facilities are required. We consider it to be easily used and widely available in most clinical laboratories.

Effectiveness of calcium and magnesium on testicular sulfatase activity

Nucleotides and calcium ions have been implicated in the regulation of biosynthesis of steroids, although the exact locus of calcium activity is not yet known. The administration of Ca2+ to Leydig cells increases testosterone production. Steroid sulfatase activity is reported to be enhanced by adenine nucleotides. In the present study the testicular sulfatase was evaluated in subcellular fractions by conversion of sulfate to free steroids in the presence or absence of Ca2+ and Mg2+ ions. The specific activity of the enzyme, which was located predominantly in submitochondrial fraction, showed a positive correlation with calcium, increasing 1.5-fold in the presence of 2.54 mM of calcium (62 nmol/h mg protein-1). In contrast, magnesium inhibited the enzymatic activity 1.79-fold in presence of 1.18 mM (23 nmoles/h mg protein-1). It would appear that testicular sulfatase is predominantly located in the mitochondria, which is recognized as one of the major sites of control of intracellular metabolism, and that its enzymatic activity could be modulated by calcium regulating the levels of potentially active androgens.

Purification and characterization of a binding protein related to the Z class of cytosolic proteins in guinea-pig liver cytosol (guinea-pig Z protein)

The purification and characterization of a low-molecular-mass binding protein from female guinea-pig liver cytosol is reported. Its molecular mass (14.4 kDa), amino acid composition, abundance and biological properties identify it as belonging to the Z class of liver cytosolic proteins [Levi, A.J., Gatmaitan, Z. & Arias, I.M. (1969) J. Clin. Invest. 48, 2956-2167]. Among the most important members of this class of proteins are the fatty-acid-binding proteins (FABPs) and the sterol carrier protein2 (SCP2). The guinea-pig Z protein (G-ZP) has some similarities in its amino acid composition and NH2-terminal sequence with those of the rat liver FABP, but its isoelectric point is basic (pI 8.85), like that of SCP2. We also examined its binding affinities for a number of ligands bound by these two proteins. The results show that the purified G-ZP binds dehydroepiandrosterone sulfate, estrone sulfate, oleic acid and cholesterol, but shows no affinity for free steroids such as estrone and DHEA. Thus it can be said that G-ZP has some characteristics of FABPs and some of SCP2 but seems, however, to be different from both these proteins. The purified G-ZP inhibits microsomal DHEA sulfate sulfatase activity in a mixed noncompetitive way. This protein could be involved in the transport and/or metabolism of sulfated steroids.

Steroid sulfatase in the human ovary and placenta: enzyme kinetics and phosphate inhibition

In 5 placental homogenates the Km of steroid sulfatase for DHEA sulfate increased from 15.4 in Tris buffer to 26.8 microM in phosphate (both buffers 0.1 M, pH 7.4), P less than 0.05. In 3 pooled ovarian preparations the Km increased from 14.3 microM in Tris to 33.0 microM in phosphate, P less than 0.01. There was no significant difference between the ovarian and placental values for Km in either Tris or phosphate (P greater than 0.5), and the increase in the Km produced by phosphate in ovarian tissue was not significantly different from that in the placenta (P greater than 0.5). In the placentas the Vmax in Tris was 1420 pmol/min/mg protein and this fell to 523 pmol/min/mg protein in phosphate (P less than 0.005). The Vmax was 50-fold higher in the placenta than in the ovary in either Tris or phosphate (both P less than 0.001). In the ovary, the Vmax was 27.6 pmol/min/mg protein in Tris and 11.0 pmol/min/mg protein in phosphate (P less than 0.05). The reduction of Vmax produced by phosphate in the ovary was not significantly different from that in the placenta (P greater than 0.5). The slope of the 1/v vs 1/S plot (Km/Vmax) increased 4.7-fold in the placentas and 5.8-fold in the ovaries in phosphate over that in Tris (both P less than 0.001); the increase in the placentas was not significantly different from that in the ovaries (P greater than 0.5). Phosphate ion acts as a mixed inhibitor of both placental and ovarian steroid sulfatase.

In vitro effect of synthetic progestogens on estrone sulfatase activity in human breast carcinoma

The effect of progesterone and nine synthetic progestogens on the activity rate of microsome estrone sulfatase obtained from human breast carcinoma tissues was studied. The progestogens were classified into three groups: group I with a strict inhibitor effect: demegestone and chlormadinone acetate; group II with a strict activator effect: medroxyprogesterone acetate, quingestanol acetate, lynestrenol and progesterone and group III with a nonsignificant effect: dydrogesterone, promegestone, norgestrel and danazol. Demegestone was the most potent inhibitor and medroxyprogesterone acetate and quingestanol acetate had the highest activator effect. The effect of Triton X-100, a nonionic detergent, was also tested. This detergent consistently increased the microsome estrone sulfatase activity. A comparison was made between the effects of demegestone, medroxyprogesterone acetate and danazol on estrone sulfatase activity measured with or without Triton X-100 in the incubation medium. The presence of the detergent modified the progestogen action. Our results suggest that synthetic progestogens can influence the estrone sulfatase activity measured in human breast carcinoma tissues. However, the effect of progestogens was dependent on experimental conditions. Progestogens such as demegestone and chlormadinone acetate which inhibited estrone sulfatase activity in intact preparations, can reduce the intracellular production of biological active estrogen via the sulfatase pathway.

Placental steroid hormones

The intent of this review was a selective consideration of recent advances in understanding placental steroidogenesis in humans. While we have omitted material, both intentionally and unintentionally, we hope this discourse presents a flavour of the current molecular endocrinology of placental steroidogenesis. In particular, advances in knowledge as it relates to the enzymes involved in progesterone and oestrogen metabolism have been addressed and correlated with placental development. Finally, because relatively less is known about regulation of steroidogenesis in the human placenta beyond the aspects of growth and differentiation, we have discussed regulation in general terms using recent data obtained in animal species.

X-linked ichthyosis and ichthyosis vulgaris: comparison of their clinical features based on biochemical analysis

Thirty cases of X-linked ichthyosis (XLI) and 32 cases of ichthyosis vulgaris (IV) were diagnosed by measuring the steroid sulphatase activity of peripheral blood lymphocytes or the electrophoretic mobility of serum LDL or both. The clinical features of the two conditions were then compared. In both diseases 60-66% of patients had a family history of the condition. Ichthyosis was noted at birth or immediately afterwards in 59% of the patients with XLI while it appeared in infancy in 68% of those with IV. Scales were mostly large and brown or dark brown in patients with XLI, while the majority of patients with IV had small brown or light brown scales. The distribution of the ichthyotic lesions differed in the two types of ichthyosis. On the trunk, the abdomen was more severely involved than the back in 63% of the cases with the XLI, whereas the back was more scaly than the abdomen in 44% of those with IV. On the extremities, the extensor surface was more severely affected than the flexor surface in both types. X-linked ichthyosis was characterized by the presence of lesions in the pre-auricular area, which were found in 93% of the cases with XLI, while only 17% of the IV patients had ichthyotic lesions at this site. Involvement of the preauricular area could be an important clinical feature for distinguishing XLI from IV.

Linkage of the murine steroid sulfatase locus, Sts, to sex reversed, Sxr: a genetic and molecular analysis

We present genetic and molecular data demonstrating linkage of the gene for steroid sulfatase (Sts) to the mutation sex reversed (Sxr) definitively showing the existance of a functional allele for Sts mapping to the pseudoautosomal region of the mouse Y chromosome. Thus, in mouse, functional Sts genes are present in the pseudoautosomal region of both the X and Y chromosomes. This is in contrast to man where Sts has been mapped to the short arm of the X just centromeric to the pseudoautosomal region. Only a single recombinant separating Sts and Sxr was found out of 103 male meioses analyzed; double recombinants were not found between sex (Tdy), Sts and Sxr. If the rate of recombination in the pseudoautosomal region in male mice is equivalent to that in man and thus 7-10X higher than normal, then our data suggest that the distance between Sts and Sxr (or the telomere of the Y) is approximately 100-200 kb in length. Our data is in contrast to a recent report of a recombination frequency separating Sts and Sxr of as high as 6.2-9.8%.

Lack of correlation between steroid sulfatase activities and lipid content in uterus and liver microsomes of guinea pigs

Lipid content and steroid sulfatase activities were determined in liver and uterus microsomes of non-pregnant guinea pigs. The results were compared with values obtained in pregnant and cortisol-treated animals. Steroid sulfatase activities were always higher in pregnant animals, and we supposed that the increase in circulating cortisol in pregnant guinea pigs before parturition has an influence on the membrane-bound sulfatase activities. Sulfatase activities were identical in cortisol-treated and untreated non-pregnant females, although cortisol induced changes in microsomal lipid composition. These results lead us to three conclusions: in intact female guinea pigs, cortisol induces variations in the lipid content of uterus and liver microsomes, especially in the cholesteryl sulfate to phospholipid ratios; the variations of the lipid composition in pregnant animals do not appear to be cortisol-dependent; membrane-bound steroid sulfatase activities are not directly influenced by the lipid composition of microsomes.

A radioimmunoassay for plasma dehydroepiandrosterone sulphate incorporating placental steroid sulphatase as a hydrolysing reagent

We describe a method for the measurement of plasma dehydroepiandrosterone sulphate (DHAS) which incorporates a Triton X-100 solubilised preparation of human placental steroid sulphatase as a hydrolysing agent and a direct radioimmunoassay of liberated DHA using a specific antiserum. The hydrolysis procedure is carried out at 50 degrees C for 1 h and an assay run can be completed in 4 h. As determined by the method, plasma concentrations of DHAS in 32 normal adult men (ages 23-58 yr) had a mean value +/- SD of 5.5 +/- 1.89 mumol/l. For 30 normal adult cyclic women (ages 22-35 yr) the mean plasma concentration of DHAS +/- SD was 3.1 +/- 1.35 mumol/l which was significantly lower (P less than 0.01) than found for men. Plasma DHAS concentration were also measured in 50 hirsute female patients. The mean value +/- SD was 5.03 +/- 2.52 mumol/l which was significantly higher (P less than 0.01) than the value for the normal female group. Some 42% of the hirsute patients had DHAS concentrations above the upper 95% probability limit of the normal range for premenopausal women.

A dehydroepiandrosterone sulfatase inhibitory activity in soluble proteins of guinea pig liver

An inhibitor of microsomal dehydroepiandrosterone sulfatase was found in the soluble fraction of non-pregnant guinea pig liver. The extent of inhibitory effect was dependent on the concentration of soluble proteins. The inhibitor was partly purified by gel permeation and hydroxylapatite chromatography with a purification factor of 16.6. The soluble inhibitor was non-dialyzable, not destroyed by RNase or DNase digestion but totally destroyed by pronase digestion. The inhibitor is a soluble protein with a molecular weight of approximately 17,000 (determined by gel permeation chromatography). Inhibition of microsomal dehydroepiandrosterone sulfatase by the soluble inhibitor is a non-competitive inhibition. From this present finding the question arises whether the inhibitor could be involved in the regulation of the hydrolysis of dehydroepiandrosterone sulfate in the guinea pig liver.

Recessive X-linked ichthyosis: lack of immunologically detectable steroid sulfatase enzyme protein

Patients with recessive X-linked ichthyosis (RXLI), one hereditary form of scaly skin, lack activity of the enzyme steroid sulfatase in all tissues studied. To investigate the molecular defect underlying the lack of enzyme activity, we prepared antisera against normal enzyme by injecting normal placental microsomal suspensions or partially purified steroid sulfatase into rabbits. Antibody activity was assessed by immunoprecipitation of detergent solubilized steroid sulfatase. In addition, we prepared rabbit antisera against RXLI placental microsomal suspensions. To detect immunologically cross-reactive material in patients' placentas, extracts were studied by immunoblot techniques and by competition with normal enzyme for antibody binding. Patients' extracts did not contain immunoreactive material co-migrating on electrophoresis with purified enzyme nor did they inhibit immunoprecipitation of normal enzyme. Sera from rabbits immunized with RXLI placental microsomes contain no antibodies to normal steroid sulfatase, as judged by their failure to immunoprecipitate normal enzyme or to react with normal steroid sulfatase on immunoblot. Thus the mutation in RXLI appears to reduce steroid sulfatase enzyme protein as well as enzyme activity.

X-linkage of steroid sulphatase in the mouse is evidence for a functional Y-linked allele

In the human there is an X-linked gene affecting steroid sulphatase (STS) activity which, when deficient, is associated with X-linked congenital ichthyosis. The gene (STS) is located on the distal tip of the short arm and is only partially inactivated when it is on the inactive X-chromosome. In the mouse, the genetics of STS are not clear; the results of one study using XX:X0 oocyte comparisons indicated X-linkage, but three other studies using STS variants have produced segregation data compatible with autosomal linkage of murine STS. Here we present the results of STS assays of crosses of deficient C3H/An male mice to normal X0 animals which demonstrate X-linkage of STS in the mouse and indirectly indicate the existence of a functional STS allele on the Y-chromosome which undergoes obligatory recombination during meiosis with the X-linked allele.

Estrone- and dehydroepiandrosterone-sulfatase activities in human female epidermis

Estrone (E1)-sulfatase and dehydroepiandrosterone (DHEA)-sulfatase activities were studied in human female epidermis. Skin specimens were obtained by abdominal or plantar biopsies. The apparent Michaelis-Menten constants for E1 and DHEA sulfatases were 35.2 microM and 8.7 microM, respectively. A substrate inhibition was only observed for DHEA sulfatase. Both sulfatases had an elevated temperature optimum (65 degrees C). The effect of inorganic salts was also tested. In normal epidermis, E1-sulfatase activity was constantly higher than DHEA-sulfatase activity, but no correlation between these activities was observed. On the other hand, E1- and DHEA-sulfatase activities were lower in plantar than in abdominal epidermis. In plantar epidermis of palmoplantar keratoderma, large variations in E1-sulfatase activity, but no significant variation in DHEA-sulfatase activity, were observed. In human epidermis, the findings were consistent with the existence of two different sulfatases: E1 sulfatase and DHEA sulfatase. It would also appear that sulfatase activities are not linked to the abnormal shedding of plantar stratum corneum in palmoplantar keratoderma.

Estrone sulfatase activity in normal and abnormal endometrium

We investigated the activity of estrone sulfatase in normal and pathological endometrium. In normal endometrium, the estrone sulfatase activity [pmol E1 X min-1 X (mg prot)-1] was 23.13 +/- 8.44 (mean +/- SD). An increase (p less than 0.01) of estrone sulfatase activity (62.81 +/- 21.97) was noted in mild endometrial hyperplasia. In focal hyperplasia (when the measurements were performed in the normal endometrial biopsies) such an increase was not noted (19.10 +/- 5.33). Estrone sulfatase activities of moderate hyperplasia (25.30 +/- 11.40) and endometrial neoplasia (30.30 +/- 9.57) were in the same range as in normal endometrium. Treatment with progestagen simultaneously reduced hyperplasia and estrone sulfatase activity. But when morphologically abnormal endometrium persisted after treatment, estrone sulfatase activity remained increased. The increase of estrone sulfatase activity appeared to be specific to mild endometrial hyperplasia. The role of estrone sulfatase in the pathogenesis of endometrial hyperplasia is discussed.

New assay for steroid sulfatase (EC 3.1.6.2) and its application for studies of human placental and skin sulfatase

A new, simple, fast and highly practicable sulfatase assay and its application is described. Sterol sulfatase sulfohydrolase (EC 3.1.6.2) activity is determined by a two-phase scintillation technique separating the unreacted [4-14C]dehydroepiandrosterone sulfate from carbon-14-labeled products. The principle of the separation relies on the limited emulsifying capacity of the dioxane-based scintillation solution for water and the different partition of dehydroepiandrosterone sulfate and sulfate-free steroid products between the scintillation fluid and the aqueous phase as recently applied for determination of aromatase activity [1]. [7-3H]Dehydroepiandrosterone sulfate can also be used as a substrate for this assay. This test was applied to studies of microsomal sulfatase prepared from human term placenta and to the detection of sulfatase activity in human skin biopsies. Using placental microsomes, the Km of dehydroepiandrosterone sulfate was determined to be 5.0 X 10(7)M. Sulfatase activity in frozen scrotal skin was found to be 2-3 fold than with vaginal skin. Using an incubation time of 24h/skin sulfatase can be detected in biopsies as small as 2.5 mm2. The sulfatase assay can be applied for routine detection of human placental sulfatase deficiency and, furthermore, the application of this assay has to be demonstrated for the analysis of sulfatase activity in patients with congenital ichthyosis (X-chromosomal, recessive type).

Steroid sulfatase activities in normal and cirrhotic livers and plasma levels of estrone sulfate, estrone and estradiol-17 beta in men

Estrone and dehydroepiandrosterone (DHEA) sulfatases were studied in livers of normal and cirrhotic men. Their Km were 3.2 microM and 1.2 microM respectively. The microsomal sulfatases were solubilized by Miranol H2M and ultrasound. After gel filtration, the soluble material gave a single peak of activity for both substrates with a molecular weight of approximately 330,000. In terms of pmol of product.min-1 per mg of fresh tissue, the mean (+/- SD) values of estrone and DHEA sulfatase activities were lower in cirrhotic livers [(n = 7) (4.09 +/- 2.90 and 0.38 +/- 0.20)] than in normal livers [(n = 13)(8.29 +/- 4.00 and 0.69 +/- 0.20)]. The differences were statistically significant : p less than 0.03 for estrone sulfatase and p less than 0.01 for DHEA sulfatase. In cirrhotic men, the mean level of plasma estrone is increased whereas that of estrone sulfate is decreased. The variations may be related to the decrease of serum albumin in cirrhotic subjects.

Cholesterol sulphate in the microsomal sulphatase deficient placenta

Placental sulphatase deficiency (PSD) and recessive X-linked ichthyosis (RXLI) are known as a nosological entity, due to deficiency of the enzyme, steroid sulphatase. Prior studies have demonstrated high urinary excretion and some accumulation of sulphated steroids prenatally, and of accumulation of cholesterol sulphate postnatally. This study was undertaken to investigate the level of cholesterol sulphate in the sulphatase deficient placenta. Whereas cholesterol sulphate levels are elevated in blood, erythrocyte membrane and stratum corneum of patients with RXLI, cholesterol sulphate content of four investigated sulphatase deficient placentas was normal in comparison to six normal male controls and four male controls with low oestrogen excretion in the third trimester of pregnancy but with normal placental sulphatase activity. The explanation for normal cholesterol sulphate content of sulphatase deficient placentas is unknown but may be due to placental transport, rapid metabolism to other sulphated steroids or age-related differences in residual enzyme activities.

Human placental steroid sulphatase--purification and monospecific antibody production in rabbits

Human steroid sulphatase was purified 43-fold from placental microsomes using a four step procedure: solubilization with Miranol H2M, Bio-Gel A 1.5 m chromatography, column chromatofocusing and Sephadex G-75 chromatography. The purified enzyme that appeared electrophoretically homogeneous was used to immunize rabbits. Protein blotting demonstrated that the resulting antiserum mainly reacted with a polypeptide of 63 000 dalton, which is about the size of placental steroid sulphatase. The antiserum was freed from minor impurities by absorbing it to Sepharose 4B with immobilized antigens prepared from a steroid sulphatase deficient placenta.

The nature of placental steroid sulphatase deficiency in man

Human placental steroid sulphatase was partially purified from microsome suspensions of control and steroid sulphatase deficient placentae. After polyacrylamidegel electrophoresis, staining for protein and enzymatic activity revealed that steroid sulphatase from control placenta migrates at Rf = 0.44. In steroid sulphatase deficient microsomes no protein band and only a very faint sulphatase activity band could be detected at Rf = 0.44. Immunoelectrophoresis employing antisera raised against both steroid sulphatase preparations, only gave a protein precipitation line with sulphatase activity when using control placenta microsomes and the antiserum against steroid sulphatase from control placenta. All other placental microsomes-antisera combinations appeared to be negative. Our results strongly suggest that the nature of X-linked steroid sulphatase deficiency is a decreased amount of steroid sulphatase protein.

Human placental steroid sulfatase: purification and properties

Steroid sulfatase is recovered quantitatively from the 105,000 g h supernatant of human placental microsomes extracted with Triton X-100. The solubilized enzyme has been purified using conventional techniques. Throughout the purification procedure, steroid sulfatase appears to be heterogeneous as evidenced by certain, but not all, criteria. Following polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, the final preparation exhibits a major component and varying amounts of two minor ones. Antibodies raised in rabbits with the heterogeneous immunogen give rise to a single precipitation line when the native enzyme is analyzed by double immunodiffusion or by immunoelectrophoresis. In addition, using aged preparations of microsomes and immunoaffinity techniques, steroid sulfatase activity was found to be associated with the fastest migrating minor component. This finding would suggest that the apparent heterogeneity of purified steroid sulfatase is linked to degradation processes occurring within the microsomal preparations. Steroid sulfatase has a Stokes radius of 56 A, a sedimentation coefficient of 4.85 +/- 0.15S (in Triton-containing buffers) and binds 1.3 g of Triton X-100-per g of protein. The molecular weight of the Triton-protein complex was calculated to be 166,000 in which the glycoprotein portion contribution is about 43% (72,000). In contrast, the apparent molecular weight of the major polypeptide determined on calibrated SDS-gels is 62,000. The purified enzyme exhibits two pH optima with cholesterol sulfate as substrate, an acidic one at pH 5.0 and a second one at pH 7.5. The Km values for cholesterol sulfate, dehydroandrosterone sulfate and p-nitrophenylsulfate were 5.26, 14 and 1,320 microM, respectively.

Aromatase activity of steroid sulphatase-deficient placentae

Aromatase activity was measured in homogenates from steroid sulphatase deficient and steroid sulphatase positive placentae. The activity of the aromatase complex was determined from the rate of formation of [14C] oestrone plus [14C] oestradiol when [14C] testosterone was incubated with a rate-limiting quantity of homogenate. A reduced level of aromatase activity was found in vitro in 70% of steroid sulphatase-deficient placentae tested, but the deficiency was much less complete than that of steroid sulphatase. The mean (+/- SD) aromatase activity of steroid sulphatase-deficient placentae was 380 +/- 180 pmol product/h/g tissue (n = 10), significantly lower (P less than 0.001, t-test) than the mean aromatase activity of steroid sulphatase positive placentae (701 +/- 70 pmol product/h/g tissue, n = 10). Seventy per cent of the steroid sulphatase deficient placentae showed lower aromatase activity than that of normal placentae stored for a comparable period of time. Assay imprecision and the sex of the foetus were excluded as reasons for the diminished aromatase activity found. It may arise through an abnormal gene product and consequent alterations in the structure of the microsomal membrane in which both aromatase complex and steroid sulphatase enzymes are retained.

Regulation of steroid-transforming enzymes by endogenous steroids

The biosynthesis of C21, C19, and C18 steroids in adrenal, ovary, testis and foeto-placental unit is summarized and the properties of the enzymes involved are described, with particular reference to their substrate specificities and to the possible controlling effects of endogenous steroids. It is concluded that these may exert a considerable regulatory role in vivo in steroid hormone biosynthesis.

The ichthyoses--pathogenesis and prenatal diagnosis: a review of recent advances

Disturbances in the process of normal cornification leading to pathologic scaling provide the pathophysiologic basis for the ichthyoses. These disturbances may result from either abnormalities in protein metabolism (keratinization) (i.e., the "bricks") or in lipid metabolism (i.e., the "mortar") (Fig. 1). The evidence linking the various ichthyoses to defects in protein or lipid metabolism have been reviewed. It is likely that future advances will lead not only to a more complete understanding of the pathogenesis of these disorders, but also will shed significant light on the normal stratum corneum functions of barrier formation and desquamation, as well as lead the way to more rational and effective therapies. In recent years, prenatal diagnosis has been successfully performed in several of the ichthyoses. It is likely that improvements in our ability to prenatally diagnose those disorders will advance hand-in-hand with further progress in unraveling their underlying causes.

Studies of the biochemical basis of steroid sulphatase deficiency--III. Phospholipid composition of microsomes from normal and steroid sulphatase deficient placentas

The phospholipid composition has been determined for placental microsomes from 11 normal and eight pregnancies complicated by steroid sulphatase deficiency. Phosphatidylcholine, phosphatidylethanolamine and sphingomyelin were found to be the major phospholipids of normal placental microsomes, comprising respectively 41.6 +/- 4.6% (mean +/- SD). 30 +/- 5.7% and 22.5 +/- 4.9% of the total phospholipid content. There was no correlation between the steroid sulphatase activity of the microsomes and the content of any of the three phospholipids. Though their contents were significantly decreased. (P less than 0.001) phosphatidylcholine, phosphatidylethanolamine and sphingomyelin similarly constituted the major portion of the total phospholipids in sulphatase deficient microsomes, representing 36 +/- 4.2%, 34 +/- 6.1% and 22.4 +/- 6.7% respectively. Only the percentage of phosphatidylcholine was significantly different (P less than 0.02) from normal microsomes. The results show that the decreased phospholipid content of steroid sulphatase deficient placental microsomes reflects a lower content of all major classes of phospholipids, particularly phosphatidylcholine.

Arylsulphatase C and estrone sulphatase of sheep hypothalamus, preoptic area, and midbrain: separation by hydrophobic interaction chromatography and evidence for differences in their lipid environment

Arylsulphatase C and estrone sulphatase activities of sheep hypothalamus-preoptic area-midbrain were examined for their susceptibility to phospholipase action. Russel's viper phospholipase A could completely inactivate estrone sulphatase without affecting arylsulphatase C. The latter was partially inactivated by S. aureus phospholipase C but not by C. welchi phospholipase C. Both arylsulphatase C and estrone sulphatase were inactivated to different extents by sodium deoxycholate, which is known to activate the intrinsic phospholipases of brain. Hydrophobic interaction chromatography on phenyl-Sepharose resulted in the differential elution of arylsulphatase C and estrone sulphatase. The results suggest that one enzyme is not responsible for arylsulphatase C and estrone sulphatase activities.

Antenatal diagnosis of steroid sulphatase deficiency: case report and literature survey

Steroid sulphatase deficiency is a recently recognised genetically determined inborn error of metabolism. Originally identified as an enzyme disorder of the placenta (commonly termed placental sulphatase deficiency), it is now known that the progeny of affected pregnancies have a generalised steroid sulphatase deficiency and that the enzyme defect persists throughout life. The disorder is characterised clinically by markedly low maternal oestrogen excretion in the presence of normal fetal growth and development. The importance of antenatal diagnosis lies in the differentiation of this disorder from the more ominous fetal defects that result in low oestrogen concentrations. This paper summarises the relevant literature and describes a case in which biochemical tests were used for the antenatal diagnosis of steroid sulphatase deficiency. The pregnancy resulted in a healthy baby boy delivered vaginally after a spontaneous labour.

Review: genetics of steroid sulphatase deficiency and X-linked ichthyosis

Steroid sulphatase deficiency which started out as a curious placental microsomal enzyme deficiency associated with low maternal urinary oestrogen excretion and difficulties in delivery, first described only twelve years ago, has now become a generalized enzyme deficiency associated also with a common skin disease. It turns out not only to be inherited in an X-linked recessive manner, but to be part of a gene cluster which includes the Xg blood group gene and which has been precisely assigned to the distal tip of the short arm of the X-chromosome. This cluster is unique for genes on the X-chromosome in escaping X-inactivation. It remains to be unequivocally demonstrated whether steroid sulphatase is identical to arylsulphatase C or whether these are two enzymes sharing a common polypeptide chain determined by a single gene. However, Rose (1982) presents evidence that one steroid sulphatase is probably identical with arylsulphatase C. It also remains to be conclusively demonstrated whether the gene for the enzyme deficiency is also that for ichthyosis or whether they are two very closely linked genes. If the former is true the role of steroid sulphatase in the abnormal keratinization of ichthyosis is still to be elucidated. Above all the special nature of the DNA in this unique region awaits description.

Activity of steroid sulfatase in fibroblasts with numerical and structural X chromosome aberrations

In cultured fibroblasts of patients with numerical and structural X chromosome aberrations the activity of steroid sulfatase (STS) is correlated with the number of functional STS gene copies. While normally, this X-linked gene is not inactivated, our data suggest that it may be subject to inactivation when carried on a structurally altered X-chromosome. Similar inactivation patterns have been reported earlier for the Xg locus which, like STS, is located on the distal portion of Xp.

Steroid sulfatase of human leukocytes and epidermis and the diagnosis of recessive X-linked ichthyosis

Patients with recessive X-linked ichthyosis, one of the inherited types of excessive stratum corneum cohesion, have deficient steroid sulfatase in fibroblasts grown from their dermis. Because of the expense and long period required to grow such cells, we have assayed this enzyme in peripheral blood leukocytes and found it to be undetectable in those from patients with this type of ichthyosis, but normal in those from patients with other hereditary or acquired types of ichthyosis. In addition, steroid sulfatase activity is less in leukocytes from women who are carriers of this disease than normal women, and this assay can be used to detect such carriers. Despite previous studies demonstrating that the gene for this enzyme escapes the inactivation of other x-chromosome genes, normal women have leukocyte steroid sulfatase activity only 1.3 times that of normal men, suggesting that some gene dosage compensation occurs. Normal human epidermis, the tissue most affected clinically, also expresses steroid sulfatase activity. The epidermal enzyme is similar in its subcellular localization, its molecular size, and kinetically to that of placenta, leukocytes, and fibroblasts.