Induction of hormone-sensitive lipase/cholesteryl esterase gene expression by C/EBPα independently of the PKA pathway in the adrenocortical Y-1 cells

The effect of C/EBPα on the expression of LIPE gene encoding hormone-sensitive lipase/cholesteryl esterase (HSL) was investigated in Y-1 CCL79 cells. It was found that transfection of these cells with the vector overexpressing C/EBPα increased both the level of LIPE transcript, measured by RT-qPCR, and the luminesce emitted by luciferase reporter gene fused to the -2150 fragment of LIPE promoter. Activation of adenylyl cyclase by forskolin resulted in 2.5-fold increase in the intensity of luminescence and over 3-fold increase in luminescence was observed when the cells were cotransfected with the vector overexpressing C/EBP. The incubation of C/EBP-cotransfected cells with forskolin caused over 6-fold increase in the intensity of luminescence, suggesting that the effects of C/EBPα and forskolin are additive. The analysis of sequence of the proximal LIPE promoter showed multiple binding sites for various transcription factors including C/EBPα site, which is located between nucleotides -46 bp and -59 bp. When the Y-1 cells were transfected with the recombinant vector containing -60 bp fragment of LIPE promoter fused to the luciferase reporter gene and were cotransfected with the vector overexpressing C/EBPα, the luminescence increases about 9-fold indicating that C/EBPα stimulates the expression of LIPE by reacting with its response element. The results indicate that C/EBPα stimulates the expression of LIPE independently of the PKA pathway by binding to a response element situated within the -60 bp fragment of LIPE promoter. This suggests that C/EBPα might be involved in the regulation of LIPE expression and thus cholesterol supply for steroid hormone synthesis.

SF-1 (NR5A1) expression is stimulated by the PKA pathway and is essential for the PKA-induced activation of LIPE expression in Y-1 cells

In the adrenal cortex, corticotropin induces the expression of several genes encoding proteins involved in the synthesis and intracellular transport of steroid hormones via the protein kinase A (PKA) signalling pathway, and this process is mediated by steroidogenic factor-1 (SF-1). This study was designed to elucidate the influence of the PKA and PKC pathways on the expression of the SF-1 gene in mouse adrenocortical cells, line Y-1. It has also been attempted to answer the question whether or not SF-1 plays a role in the PKA-induced expression of LIPE gene encoding hormone-sensitive lipase/cholesteryl esterase, which supplies cholesterol for steroid hormone synthesis. In this study, we found that stimulation of the PKA pathway caused a significant increase in SF-1 expression, and that this effect was abolished by the PKA inhibitor, H89. Decreased SF-1 gene transcript levels were seen with the simultaneous activation of PKA and PKC, suggesting a possible interaction between the PKA and PKC pathways. It was also observed that SF-1 increased the transcriptional activity of the LIPE gene by interacting with the SF-1 response element located in promoter A. Moreover, transient silencing of SF-1 expression with specific siRNAs abolished PKA-stimulated transcription of the LIPE gene, indicating that SF-1 is an important regulator of LIPE expression in Y-1 cells and thus could play a role in the regulation of the cholesterol supply for adrenal steroidogenesis.

A novel insA2933 causes premature termination of translation and is accompanied by overexpression of truncated androgen receptor gene in a patient with complete androgen insensitivity syndrome

A patient with a female phenotype, 46,XY karyotype, and a diagnosis of complete androgen insensitivity syndrome (CAIS) was examined. Her mother and three 46,XX sisters were also included in the study. Sequence analysis of the androgen receptor gene (AR) revealed a novel A2933 insertion that alters the Tyr codon to a termination codon (Y857X), resulting in a truncated form of the receptor. Computer simulation revealed major conformational changes in the hydrophobic pocket that accommodates the hormone. An insA2933 results in a truncated receptor incapable of binding the ligand and is responsible for the clinical symptoms of CAIS in the patient. The levels of the AR transcript in peripheral blood leukocytes were higher in the patient than in her heterozygous mother and her heterozygous sister, as well as in the two healthy sisters. It is hypothesized that elevated levels of the AR transcript in the patient might be caused by the inability of the truncated receptor to react with IFI-16, which functions in complex with AR to inhibit the expression of the AR gene.

Identification of mutations in the HVR1 and PKR-BD regions in HCV-infected patients resistant to PEG-IFNα/RBV therapy

The identification of mutations in the HVR1 region of hepatitis type C virus (HCV) is time-consuming and expensive, and there is a need for a rapid, inexpensive method of screening for these mutations to predict the ineffectiveness of pegylated interferon alpha combined with ribavirin (PEG-IFNα/RBV) therapy. The project was designed to evaluate the usefulness of the high resolution melting (HRM) technique to screen for mutation in the cDNAs encoding the HVR1 and protein kinase R-binding domain (PKR-BD) regions in a group of 36 patients infected with HCV and resistant to 12 months of combined therapy with PEG-IFNα/RBV. Viral RNA was isolated, reverse transcribed, and the fragments encoding the HVR1 and PKR-BD regions were polymerase chain reaction (PCR)-amplified, cloned, sequenced, and the melting profiles and the melting temperature (T_m) were determined by the HRM technique. After the treatment, the melting profiles of HVR1 cDNAs revealed a dominant peak corresponding to the T_m of about 85 °C (HCVs85) in almost all patients. One or more minor peaks were also observed, indicating the existence of cDNA(s) of different T_m. The HMR analysis suggested four typical forms of response to treatment. These suppositions were supported by sequencing. The HRM analysis revealed no changes in the melting profiles of PKR-BD cDNAs in the same patient before and after the therapy, suggesting that, within 12 months of treatment, new mutations were not introduced in PKR-BD. These findings were substantiated by sequencing. The HRM technique can be applied for the rapid screening for mutations in the cDNAs encoding the HVR and PKR-BD regions of HCV. We suggest that the detection of HCVs85 peak before the IFNα/RBV therapy might predict the ineffectiveness of treatment.

A rare heterozygous TRAF6 variant is associated with hypohidrotic ectodermal dysplasia

BACKGROUND

Mutations in the genes encoding components of the tumour necrosis factor (TNF)-α-like pathway cause hypohidrotic ectodermal dysplasia (HED). It has been postulated that the TNF receptor-associated factor 6 (TRAF6) is also involved in this pathway.

OBJECTIVES

To investigate mutations in the TRAF6 gene in an individual with HED.

METHODS

Genetic analysis was performed on TRAF6 in a patient with HED, her parents, her sister and 150 ethnically matched, healthy individuals.

RESULTS

In the patient, sequencing analysis of one DNA strand revealed a deletion of eight nucleotides (c.1074-1081delCAATTTG) in the 5' fragment of the last exon of TRAF6, while no deletion was detected in the other DNA strand indicating a heterozygous mutation. No such sequence abnormality was detected in the patient's parents and her sister.

CONCLUSION

This is the first report of a heterozygous TRAF6 sequence variant associated with symptoms typical of HED.

Transcription of LIPE gene encoding hormone-sensitive lipase/cholesteryl esterase is regulated by SF-1 in human adrenocortical cells: involvement of protein kinase A signal transduction pathway

The study was designed to elucidate the influence of the protein kinase A (PKA) signal transduction pathway on transcription of the LIPE gene encoding hormone-sensitive lipase/cholesteryl esterase (HSL) in H295R cells. HSL is one of the key enzymes involved in steroid hormone synthesis, and ACTH, with mediation of the PKA pathway, increases its activity. However, the mode of regulation of LIPE gene expression by ACTH remains unknown. It was found that stimulation of the PKA pathway by the adenylyl cyclase activator, forskolin, caused a twofold increase in LIPE transcript accompanied by appreciable rise in the protein product of the gene and cortisol output. RNA polymerase II inhibitor abolished, and protein synthesis inhibitor attenuated this effect. Forskolin and PKA catalytic subunit increased transcriptional activity of LIPE promoter A in cells transfected with the luciferase reporter vector. Overexpression of steroidogenic factor-1 (SF-1) increased LIPE promoter activity, while transient silencing of SF-1 expression with specific siRNAs abolished forskolin-stimulated LIPE transcription. It is concluded that ACTH via the PKA pathway stimulates expression of SF-1, which activates transcription of LIPE presumably by interaction with putative binding sequences within promoter A. A novel mechanism contributing to the long-term effect of ACTH on adrenal steroidogenesis is proposed: ACTH stimulates transcription of SF-1, which interacts with the putative SF-1-binding sequences within the promoter and activates LIPE transcription. An increased level of HSL results in an enhanced supply of cholesterol required for steroid hormone synthesis.

The correlation of homocysteine-thiolactonase activity of the paraoxonase (PON1) protein with coronary heart disease status

Homocysteine (Hcy)-thiolactonase (HTase) activity of the paraoxonase-1 (PON1) protein detoxifies Hcythiolactone in human blood and could thus delay the development of atherosclerosis. We investigated a hypothesis that HTase activity is associated with coronary heart disease. We studied HTase activities and PON1 genotypes in a group of 475 subjects, 42.5% of whom were healthy and 57.5% had coronary heart disease (CHD). We found that HTase activity was positively correlated with total cholesterol (r=0.254, P<0.0001), LDL cholesterol (0.149, P=0.016), ApoB (r=0.167, P=0.006), ApoA1 (0.140, P=0.023), and HDL cholesterol (0.184, P=0.002) in a group of CHD cases (n=270) but not in controls (n=202). Mean HTase activity was significantly higher in CHD cases than in controls (4.57 units vs. 3.30 units, P <10(-5)). The frequencies of the PON1-192 genotypes in CHD cases were similar to those in controls. HTase activity was not different between patients receiving statins and those not treated with statins. Multiple regression analysis shows that CHD status, PON1 genotype, and total cholesterol are determinants of HTase activity in humans. Our results suggest that HTase activity of the PON 1 protein is a predictor of CHD.

A correlation between the heterogeneity of hypervariable region 1 of E2 glycoprotein of Hepatitis C virus (HCV) and HCV antibody profile: a case study

A correlation between the heterogeneity of hypervariable region 1 (HVR1) of E2 glycoprotein (gp) and Hepatitis C virus (HCV) antibody profile was investigated. Of 6 patients studied two were in acute phase, two in chronic phase and two showed signs of long-time HCV infection, i.e. liver cirrhosis. All the patients exhibited a vigorous antibody response to viral proteins C, NS3, NS4 and NS5. An antibody response to HVR1 of E2 was found in one patient in acute phase and in one or two patients in chronic phase. Such a response was not found in the two patients with liver cirrhosis. Single-stranded conformation polymorphism (SSCP) and sequence analyses of HVR1 of E2 showed the lowest HVR1 heterogeneity in patients in acute phase and the highest one in those in chronic phase, while the long-time carriers of the virus showed an intermediate heterogeneity. This may reflect a specific interplay between the virus and immune system. The HVR1 heterogeneity may rise in the course of infection as a means of evading the immune pressure. Then, when an organism is unable to clear the virus, because the responses to HVR1 epitopes are weakened or exhausted, a population of less heterogeneous HVR1 variants may be established.

Determinants of homocysteine-thiolactonase activity of the paraoxonase-1 (PON1) protein in humans

Homocysteine (Hcy)-thiolactonase (HTase) activity of the paraoxonase-1 (PON1) protein detoxifies Hcy-thiolactone in human blood and could thus delay the development of atherosclerosis. To gain insight into physiological role(s) of the PON1 protein, we studied HTase activities and PON1 genotypes in a group of 184 subjects, 32.6% of whom were healthy, 27.7% had angiographically proven coronary artery disease but did not have myocardial infarction (CAD), and 39.7% had myocardial infarction (MI). We found that the hydrolytic activities of the serum PON1 protein towards Hcy-thiolactone and the organophosphate paraoxon substrates were strongly correlated. PON1-192-RR and PON1-55-LL genotypes were associated with high HTase activity. HTase activity was negatively correlated with age (beta = -0.135, p =0.002), plasma total Hcy (in 192-QR subjects only; r = -0.46, p = 0.001), and positively correlated with total cholesterol (beta = 0.169, p<0.001), but not with HDL cholesterol. Mean HTase activities were similar in CAD subjects, MI subjects, and in healthy controls. However, the frequency of the PON1-192-RR genotype tended to be lower in CAD subjects than in controls (2% vs 10.0%, p = 0.057) and higher in MI subjects that in CAD subjects (10.9% vs 2.0%, p = 0.001). The R-allele was marginally associated with CAD (26.7% in controls vs 17.6% in CAD, p = 0.146) and significantly associated with MI (17.6% in CAD vs 31.5% in MI, p = 0.018). Multiple regression analysis suggests that PON1 genotype, total Hcy, total cholesterol, and age are major determinants of HTase activity in humans.

A novel c.C2754 > T transition in the androgen receptor gene introduces the premature termination codon Q798X and results in a truncated form of the receptor

A genetic analysis of a female with a 46,XY genotype and typical symptoms of the complete androgen insensitivity syndrome (CAIS) was conducted. The patient was diagnosed with an abdominal tumor due to the presence of a Sertoli cell adenoma in both gonads. Multiple temperature single-stranded conformational polymorphism (MSSCP) and sequence analyses of the androgen receptor gene revealed a c.C2754 > T mutation in exon 6. This mutation, which has not been previously reported, alters a Gln codon to a termination codon (Q798X). This results in the interruption of the amino acid sequence of the androgen receptor within the ligand-binding domain between helices VII and VIII. The truncated form of the receptor is devoid of 123 amino acids at the carboxyl end, a major part of the ligand-binding domain, and the AT2 sequence responsible for the activation of the transcription. It was concluded that the novel c.C2754 > T transition rendered the androgen receptor incapable of both ligand binding and activating the transcription, and was the cause of CAIS in the patient.

Determination of the CCR2-64I/CCR5-59653T haplotype linkage disequilibrium in a sample of Polish population

It has been reported that different polymorphisms in the regulatory regions of CCR5 and in the CCR2 gene of the chemokine receptors are associated with AIDS. We decided to determine the congruence between CCR5-59653T and CCR2-64I alleles in a group of 281 persons. Frequencies of combined CCR5-59653T and CCR2-64I haplotypes were examined in a group of 281 persons. Among 281 individuals 26 (9.3%) and 24 (8.5%) respectively were carriers of the CCR5-59653T and the CCR2-64I alleles. We also found that 24 persons (8.5%) were carriers of combined CCR2-64I/CCR5-59653T allele. The calculation of the congruence revealed that 92.0% of individuals exhibited the same genotype for both CCR2-64I and CCR5-59653T polymorphisms. Our results confirm that linkage between CCR5-59653T and CCR2-64I alleles is not absolute.

Regulation of 11beta-hydroxysteroid dehydrogenase type II expression in the renal epithelial cells

The regulation of 11beta-hydroxysteroid dehydrogenase type II (11betaHSD2) expression at the level of specific mRNA and 11betaHSD2 protein was investigated in primary culture of renal epithelial cells of the rat. It has been shown that treatment of the SE cells with adenylyl cyclase activator, forskolin, known to stimulate the protein kinase A (PKA) pathway, resulted in an increase in 11betaHSD2 mRNA content in these cells. Semi-quantitative RT-PCR revealed that the effect of forskolin was attenuated by the addition of phorbol ester, tetradecanoyl phorbol acetate (TPA), an activator of the protein kinase C (PKC) pathway, whereas TPA on its own slightly reduced the basal level of 11betaHSD2 expression judging from the content of specific mRNA. Measurements of [35S]-methionine incorporation into immunoprecipitable 11betaHSD2 revealed an increased synthesis of this protein in renal epithelial cells treated with forskolin. Phorbol ester TPA markedly reduced the effect of forskolin on the synthesis of 11betaHSD2 and attenuated the basal level of synthesis of this protein. It is concluded that in renal epithelial cells in primary culture, stimulation of PKA pathway results in the induction of 11betaHSD2 both at a specific mRNA and at a protein level and that this effect is markedly reduced by activation of PKC pathway.

Decreased density of the CCR5 receptor on the surface of CD4+ lymphocytes and monocytes/macrophages is associated with the CCR5-59653T transition in the promoter region

We compared the density of the CCR5 receptor on the surface of CD4+ lymphocytes and monocytes/macrophages of the homozygote (CCR5-59653C) and the heterozygote (CCR5-59653T), bearing CCR2-64V alleles. Flow cytometric analysis revealed lower density of the CCR5 receptor on the surface of CD4+ lymphocytes and monocytes/macrophages of the heterozygote than in the same cells of the homozygote. Our observation might explain slower replication of HIV and the delay in progression to AIDS in the individuals bearing CCR5-59653T transition.

The effect of high molecular weight dextran sulfate on the production of interleukin-8 in monocyte cell culture

It has been demonstrated that high molecular weight dextran sulfate (HMDS) is involved in the activation of immune cells. We have shown that HMDS increases the concentration of interleukin (IL)-8 in the medium of monocyte cell culture, in a dose-dependent fashion, whereas under the same conditions, low molecular weight dextran sulfate (LMDS) does not exhibit any effect on IL-8 biosynthesis. The effect of HMDS on IL-8 production is additive to that of IL-1beta and tumor necrosis factor-a (TNFalpha). Flow cytometric analysis revealed the biosynthesis of IL-8 in monocytes incubated in the presence of the HMDS. We hereby postulate that HMDS induces IL-8 biosynthesis in monocyte cell culture.

Study of the family of a patient with male-limited precocious puberty (MPP) due to T1193C transition in exon 11 of LH receptor gene

Molecular diagnostics of the LHR gene was conducted in a 5-year-old boy with clinical symptoms and hormonal profile typical of precocious puberty. His parents and 4 sisters were also diagnosed. Single-strand conformation polymorphism analysis under temperature gradient conditions (Multitemperature SSCP) of 3 overlapping fragments of exon 11 of LHR gene revealed a mutation in the fragment spanning nucleotides 1072 to 1804. This mutation was found in the patient, in his mother and in his 4 sisters, and was confirmed by digestion with the use of restriction enzyme Bbr Cl. Direct sequencing revealed a heterozygous T1193C transition in the DNA fragment of the patient and in one of the alleles of his mother's and sister's DNA. This mutation causes Met398Thr substitution in the second transmembrane helix and results in a constitutive activation of LH receptor. This is the second identical mutation detected in Poland and one of the 7 identified so far in the world population.

A novel isoform of human lymphoid enhancer-binding factor-1 (LEF-1) gene transcript encodes a protein devoid of HMG domain and nuclear localization signal

Lymphoid enhancer-binding factor-1 (LEF-1), a member of the high mobility group (HMG) family of proteins, regulates expression of T-cell receptor-alpha gene and is one of the key regulatory molecules in the epithelial-mesenchymal interactions during embryonic development. Among others, LEF-1 regulates expression of cytokeratin genes involved in formation of hair follicles and the gene encoding the cell-adhesion molecule E-cadherin. Transcription factor LEF-1, which acts as a dimer, binds beta-catenin and is involved in signal transduction by the wnt pathway. We have cloned and sequenced a novel isoform of human LEF-1 gene transcript. This isoform encodes a truncated protein devoid of HMG domain and nuclear localization signal but retaining beta-catenin binding domain. This isoform might either act in a dominant-negative manner by interfering with native LEF-1, or might bind beta-catenin in the cytosol, which would result in attenuation of the signals transmitted by the LEF-beta-catenin pathway.

Additive effect of tunicamycin and dextran sulfate on the binding of monoclonal antibody to the V2 domain of the envelope glycoprotein 120 of human immunodeficiency virus type 1

Using flow cytometry or immunoprecipitation analysis in cells chronically infected with HIV-1 IIIB Supt-1, we noticed an additive effect of tunicamycin and low molecular weight dextran (LMDS) on the binding of the G3-4 monoclonal antibody to monomeric and oligomeric forms of glycoprotein 120 (gp120). The inhibition of glycosylation by tunicamycin reduced the number of monomeric and oligomeric forms of gp120. The inhibition of the binding of the G3-4 antibody to monomeric and oligomeric forms of gp120 was more pronounced in the presence of LMDS. We also found that the G3-4 antibody can not recognise the nascent polypeptide chain of the envelope glycoprotein.

High molecular weight dextran sulphate enhances the activity of NF-kappaB-regulated promoter in monocytic cell line

It has been known that lipopolysaccharides (LPS) as well as superantigens increase activity of transcription factor NF-kappaB in monocyte-derived macrophages and monocytic cell lines. To examine the mitogenic effect of high molecular weight dextran sulphate (HMDS), the monocytic cell line THP-1 was transfected with a plasmid vector containing chloramphenicol acetyl transferase (CAT) reporter gene linked to the HIV-1 long terminal repeat (LTR) promoter, that is regulated by the transcription factor NF-kappaB. We have demonstrated that HMDS, similar to bacterial LPS, increases the expression of CAT reporter gene, indicating increased activity of NF-kappaB.

Mutations in the EDA gene in three unrelated families reveal no apparent correlation between phenotype and genotype in the patients with an X-linked anhidrotic ectodermal dysplasia

Anhidrotic ectodermal dysplasia (EDA) is caused by mutations in the EDA gene encoding ectodysplasin A, a member of the TNF ligand superfamily involved in the communication between the cells. The structure of the EDA gene was investigated in three patients exhibiting clinical symptoms of EDA in an attempt to correlate the molecular findings with the phenotype of the patients. Genomic DNA was analyzed by single stranded conformation polymorphism (SSCP) followed by direct sequencing. In one of the patients, as well as in his heterozygous mother and sister, a single T insertion was evidenced in exon 3 between nucleotides 713 and 714 that changed Lys codon (AAA) into a termination codon TAA (Lys158Ter). In the other patient, A1321T transversion was demonstrated. The same mutation was found in his heterozygous mother and resulted in a change of Ileu360Asn that might generate an additional glycosylation site. In the third patient an A1285G transition was revealed. This mutation that originated de novo was localized in a region that is highly conserved in TNF ligand family and caused substitution of Ala349Thr. Localization of the mutations in the extracellular domain of ectodysplasin A suggested that the primary cause of EDA is a defect in communication between the cells responsible for the development of skin appendages. Despite a different character and localization of the mutations, no apparent correlation between phenotype and genotype of the patients was evidenced. Some differences in the patients' phenotype were observed.

Investigations on the genetic polymorphism in the region of CYP17 gene encoding 5'-UTR in patients with polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is a prevalent endocrine disorder, which is the most common cause of anovulatory infertility and hirsutism. It is caused by an overproduction of androgens in theca cells. In the ovary, androgen synthesis is regulated by 17 alpha-hydroxylase/17,20-lyase enzyme complex containing P450c17 (CYP17). In some individuals, the promoter region of CYP17 gene contains a T-->C substitution that creates an Sp1 site at position-34. This polymorphism generates a recognition site for the MspA1 restriction enzyme. The objective of the study was to investigate the frequency of T-->C substitution of CYP17 gene promoter in women with PCOS and elucidate its role in the pathogenesis of the syndrome. Another aim of the study was to compare the results with the levels of the hormones luteinizing hormone, follicle-stimulating hormone, testosterone and estradiol. The present investigation involved a group of 55 women with PCOS and 56 healthy women without symptoms of PCOS. Following digestion with restriction enzyme MspA1, it was demonstrated that the polymorphic A2 allele is no more frequent in women with PCOS than in healthy women. In the PCOS group, the hormonal profiles were not significantly different in the carriers of a normal allele A1A1 from the carriers of A1A2 and A2A2 alleles. It is concluded that T-->C polymorphism of CYP17 gene is not associated with steroid hormone synthesis in PCOS and is not the primary genetic defect in this disease.

A novel isoform of human lymphoid enhancer-binding factor-1 (LEF-1) gene transcript encodes a protein devoid of HMG domain and nuclear localization signal

Lymphoid enhancer-binding factor-1 (LEF-1), a member of the high mobility group (HMG) family of proteins, regulates expression of T-cell receptor-alpha gene and is one of the key regulatory molecules in the epithelial-mesenchymal interactions during embryonic development. Among others, LEF-1 regulates expression of cytokeratin genes involved in formation of hair follicles and the gene encoding the cell-adhesion molecule E-cadherin. Transcription factor LEF-1, which acts as a dimer, binds beta-catenin and is involved in signal transduction by the wnt pathway. We have cloned and sequenced a novel isoform of human LEF-1 gene transcript. This isoform encodes a truncated protein devoid of HMG domain and nuclear localization signal but retaining beta-catenin binding domain. This isoform might either act in a dominant-negative manner by interfering with native LEF-1, or might bind beta-catenin in the cytosol, which would result in attenuation of the signals transmitted by the LEF-beta-catenin pathway.

Distribution of 32 alelle of the CCR5 gene in the population of Poland

The chemokine receptor CCR5 constitutes a major co-receptor for the R5 strains of HIV-1, and a mutant allele of the CCR5 gene, especially in the homozygous form delta32/delta32, confers resistance against infection by the virus. The frequency of the delta32 allele was determined in blood donors from 16 provinces, covering the entire territory of Poland. Among 861 individuals 182 (21.1%) were carriers of the mutated allele: 7 of them (0.8 %) were homozygotes delta32/delta32, and 175 (20.3%) were heterozygotes +/delta32, resulting in a 10.9% frequency of the delta32 allele. The highest frequencies of the mutated allele were found in the eastern and western provinces, and the lowest frequencies of the delta32 allele were detected in the provinces in the center of the country. This pattern of distribution may reflect the migration of the population from the eastern territories of Poland to the western part of the country after World War II.

Sequence polymorphisms of the EDA and the DL genes in the patients with an X-linked and an autosomal forms of anhidrotic ectodermal dysplasia

Oligodontia, sparse hair and deficiency of eccrine sweat glands are the features characteristic for the phenotype of the patients with anhidrotic ectodermal dysplasia (EDA). This syndrome is caused by mutations in the EDA or DL (downless) genes, encoding members of the TNF ligand and TNF receptor families, involved in the communication between the cells during embryonic life. We investigated both the coding and noncoding regions of the EDA and the DL genes in the patients exhibiting clinical symptoms of ectodermal dysplasia. Sequence analysis of the amplified fragments of the EDA gene revealed polymorphisms in introns three, four and five. The polymorphism in intron four was found in about 60% of the patients and was no more frequent than in the normal individuals. The two other polymorphisms were rare. Polymorphisms were also observed in exons 9 and 12 of the DL gene, but they did not alter the sequence of the protein product of the gene. Our results indicate that in order to accelerate screening for the mutations of the EDA gene and reduce the costs, the amplified fragments should not contain intronic sequences. However, in the case of the DL gene, where polymorphic sites are located in exons, restriction analysis with the use of appropriate enzyme should be conducted, but usually sequencing analysis could not be avoided.

Decreased susceptibility of Th1 cells to infection with primary HIV-1 isolates is associated with lower expression of CXCR4 in these cells

The HIV-1 X4-isolates replicate more efficiently in Th2 than in Th1 cells, isolated from peripheral blood lymphocytes of HIV-1 seronegative individuals. The semiquantitative RT-PCR revealed higher level of transcripts of the HIV-1 co-receptor CXCR4 in Th2 cells than in Th1 cells which might explain better replication of HIV-1 X4-isolates in these cells. Lower expression of CXCR4 in Th1 cells render these cells less susceptible to infection with HIV-1.

The novel polymorphic variants within the paired box of the PAX9 gene are associated with selective tooth agenesis

It has been reported that two genes MSX1 and PAX9, which encode transcription factors, are associated with selective tooth agenesis. Expression of these genes specifically marks the regions of the mesenchyme where the tooth buds are formed. A mutation in the MSX1 gene, detected in a single family, resulting in an Arg-->Pro substitution in the homeodomain of the protein product of this gene has previously been associated with the deficiency of second premolars and third molars. However, mutations of the MSX1 gene were excluded in the patients with agenesis of the other type of teeth. In a single family with the lack of first and second molars, a mutation in the PAX9 gene was found. In our group of patients with the deficiency of various teeth, in 20% of the patients and their relatives sequence analysis revealed a C-->T transition in the coding sequence of the PAX9 gene. However, this polymorphism does not alter amino acid sequence of the protein product of this gene.

Expression of three negative regulators of CYP17 gene transcription in adrenocortical cells

The expression of negative regulators of CYP17 gene expression: DAX-1, COUP-TF and N-CoR was investigated in bovine adrenocortical cells in primary culture. The cells were incubated for 6 hours in a defined medium, containing ACTH (10 nM) or forskolin (25 microM). Total RNA was isolated, the concentration of CYP17 gene transcript was determined by hybridization analysis, and polyA RNA was reverse-transcribed to obtain cDNA. Fragments of CYP17, DAX-1, COUP-TF, N-CoR and beta-actin cDNA were amplified by PCR and the amplified cDNAs were analyzed by agarose gel electrophoresis followed by densitometry. It was found that DAX-1 and COUP-TF mRNA levels were unaffected by treatment with ACTH or forskolin. On the contrary, both compounds enhanced the level of mRNA encoding N-CoR. Under the same conditions, ACTH or forskolin substantially stimulated CYP 17 mRNA accumulation. Our results suggest that in the adrenocortical cells in culture, the expression of DAX1 and COUP-TF is constitutive, whereas N-CoR expression might be inducible.

Substitution of M398T in the second transmembrane helix of the LH receptor in a patient with familial male-limited precocious puberty

Familial male-limited precocious puberty (MPP) is described in a 10 year old patient with typical symptoms of the disease. Sequence analysis of genomic DNA clearly demonstrated a heterozygous T1193C transition in exon 11 of the LH receptor (LHR) gene, which results in M398T substitution in the second transmembrane helix of the protein product of this gene. The same mutation was found in the patient's mother and in her brother. The grandmother and the relatives of the patient's father were free of the mutation. The boy was successfully treated with inhibitors of steroid biosynthesis and androgen antagonists. It is suggested that this mutation caused constitutive activation of the LHR, which results in excessive formation of androgens in Leydig cells and is responsible for the symptoms of precocious puberty in this patient. This is the second case of the familial form of MPP that was maternally inherited.

Cloning of the lymphoid enhancer binding factor-1 (Lef-1) cDNA from rat kidney: homology to the mouse sequence

We have cloned and sequenced rat cDNA that encodes the Lef-1 protein. The cDNA, containing 1194 nt exhibits 94% similarity to the mouse Lef-1 cDNA. The deduced amino-acids sequence of rat Lef-1 protein, consisting of 397 amino acids, exhibited 98% homology with the known sequence of mouse Lef-1 protein.

Differential expression of chemokine receptor CXCR4 in Th1 and Th2 subtypes of CD4+ lymphocytes

Different cytokine profiles allow to divide the CD4+ lymphocytes into Th1, Th2 and Th0 subtypes. It has been observed that the Th2 cells are more efficient supporters for HIV-1 replication than the Th1 cells. The Th1 and the Th2 cells were isolated from peripheral blood lymphocytes of HIV-1 seronegative individuals and the density of CXCR4 receptors was determined by flow cytometry using antibodies directed against the CXCR4 receptor. Flow cytometric analysis revealed higher expression of the HIV-1 co-receptor CXCR4 on Th2 cells than on the Th1, which might explain better replication of HIV-1 viruses in the Th2 cells.

Application of monoclonal antibodies to monitor the synthesis of a glycoprotein core of envelope glycoproteins of human immunodeficiency virus (HIV-1)

Using monoclonal antibodies 0.5 beta or G3-42, directed against V3 and C4 domains of glycoprotein 120 (gp120), we monitored the synthesis of oligomeric and monomeric forms of HIV-1 envelope glycoprotein 120 by flow cytometry or immunoprecipitation analysis in chronically infected MoIT-4 cells, cultured in the presence of tunicamycin. We observed that the inhibition of glycosylation by high concentrations of tunicamycin results in the reduction of an oligomeric gp120 on the surface of infected MoIT 4 cells as well as the decrease in the concentration of a monomeric form in the cytoplasm. Our studies revealed that the antibody 0.5 beta (exhibited higher sensitivity in the detection of gp120 than the antibody G3-42). We also observed that both antibodies did not recognise nonglycosylated precursor core envelope protein.

Cloning of the lymphoid enhancer binding factor-1 (Lef-1) cDNA from rat kidney: homology to the mouse sequence

We have cloned and sequenced rat cDNA that encodes the Lef-1 protein. The cDNA, containing 1194 nt exhibits 94% similarity to the mouse Lef-1 cDNA. The deduced amino-acids sequence of rat Lef-1 protein, consisting of 397 amino acids, exhibited 98% homology with the known sequence of mouse Lef-1 protein.

High molecular weight dextran sulfate increases the activity of NF-kappaB-regulated promoter in monocyte-derived macrophages

It is known that sulfated polysaccharides can mimic the action of common T-cell mitogens. To investigate the molecular basis of the mitogenic effect of high molecular weight dextran sulfate (HMDS), monocyte-derived macrophages were transfected with recombinant plasmid containing chloramphenicol acetyl transferase (CAT) reporter gene under the control of the HIV-1 long terminal repeat (LTR) promoter, which is regulated by transcription factor NF-kappaB. We observed that HMDS, similar to bacterial lipopolysaccharide (LPS), increases the expression of CAT reporter gene suggesting increased activity of NF-kappaB. The activation of NF-kappaB correlated with the increased expression of B7.1 molecules. It was postulated that this NF-kappaB-regulated promoter might play a role in the activation of the accessory cells as well as the rate of replication of HIV-1 in monocyte-derived macrophages.

[Molecular background of hyperandrogenism of ovarian origin]

Ovarian androgens constitute substrates for estrogen formation, the key enzyme in androgen production being 17 alpha-hydroxylase/17,20 lyase, while in estrogen synthesis, aromatase. Both enzymes are constituents of a complex, comprising two proteins: cytochrome P450 reductase and respective cytochromes P450c17 or P450arom, whose expression play an important role in a proper function of the ovaries and its genetically determined abnormalities may lead to appearance of clinical symptoms. Although it is difficult to clearly define the genetic background of disturbances, leading to hyperandrogenism, metabolic abnormalities, resulting in excessive androgen production, were observed in polycystic ovarian syndrome, hyperthecosis and hyperinsulinemia. In this review data from literature were presented and discussed regarding endocrine and molecular background of hyperandrogenism of ovarian origin.

The V3 region of gp120 is responsible for anti-HIV-1 activity of heparin sulphate

The effect of heparin sulphate on the infection of CD4+ lymphocytes by recombinant HIV-1 clones pIIIB and by pIIIB/V3-BaL was investigated. It was demonstrated that heparin sulphate decreased the infectivity of CD4+ lymphocytes by the pIIIB virus stronger than by the pIIIB/V3-BaL clone, and that the effect of heparin was concentration-dependent. This was accompanied by an inhibition of binding of the monoclonal antibodies 447-52-D to the V3 region and G45-60 to the C4 region of oligomeric glycoprotein 120 (gp120). It has been concluded that the inhibitory effect of heparin sulphate on the infection of CD4+ lymphocytes by recombinant HIV-1 clones is mediated mainly by the V3 region of gp120. However, the C4 region contributes to the inhibitory effect of heparin sulphate.

The V3 region of gp120 is responsible for anti-HIV-1 activity of heparin sulphate

The effect of heparin sulphate on the infection of CD4+ lymphocytes by recombinant HIV-1 clones pIIIB and by pIIIB/V3-BaL was investigated. It was demonstrated that heparin sulphate decreased the infectivity of CD4+ lymphocytes by the pIIIB virus stronger than by the pIIIB/V3-BaL clone, and that the effect of heparin was concentration-dependent. This was accompanied by an inhibition of binding of the monoclonal antibodies 447-52-D to the V3 region and G45-60 to the C4 region of oligomeric glycoprotein 120 (gp120). It has been concluded that the inhibitory effect of heparin sulphate on the infection of CD4+ lymphocytes by recombinant HIV-1 clones is mediated mainly by the V3 region of gp120. However, the C4 region contributes to the inhibitory effect of heparin sulphate.

Serines at the active site of 11 beta-hydroxysteroid dehydrogenase type I determine the rate of catalysis

Short chain alcohol dehydrogenases have an invariant YXXXK motif at the active site. Database analysis of 116 superfamily members showed that 92% also contain a Serine or Threonine residue at the Y + 1 or Y + 3 positions, a pattern we previously described as the ST rule. In the present study we have mutated Serines in the active site, YSASK, motif of 11 beta-hydroxysteroid dehydrogenase type I (11 beta HSD1). These studies were facilitated by the generation of a new specific polyclonal antibody (RAH113) raised against a synthetic peptide derived from the rat 11 beta-HSD1 sequence. Immunopurified RAH113 recognized a single band at 34 kDa in liver homogenates. Kinetic analysis of equivalent amounts of wild type and mutant proteins showed that mutagenesis of active site Serines resulted in modest increases of Km values for corticosterone from 325 nM for 11 beta HSD1 to 512 nM-588 nM for the S1 (YAASK), S2 (YSAGK) and S3 (YAAGK) mutants in homogenates of transfected CHOP cells. However, far greater effects were observed on the first order rate constants with mutants displaying 10%, 1% and 1% of the wild type activity, respectively. When the oxidoreductase reaction was studied in whole cells mutagenesis again had a minimal effect on the Km value but dramatically lowered first order rate constants to 34%, 5% and 6%, respectively, of the wild type. These data show that Serines at the active site of 11 beta HSD1 play an important role in determining the rate of catalysis. Coexpression of wild type and mutant enzymes did not lower wild type activity suggesting that the active site of the multimeric enzyme is not a composite of active site Serines from different subunits.

High molecular mass dextran sulfate increases expression of HIV-1 coreceptor CCR-5 in macrophage-monocytes in culture

It has been reported that high molecular mass dextran sulfate (HMDS) enhances the infection of monocyte-macrophages by HIV-1. We observed that in monocyte-macrophages maintained in the presence of HMDS the expression of HIV-1 coreceptor CCR-5 was increased approximately 5-fold at the transcriptional level. We postulate that the increased expression of CCR-5 might be responsible for HMDS-enhanced infectivity of monocyte-macrophages by HIV-1.

Mutation in the regulatory region of the EDA gene coincides with the symptoms of anhidrotic ectodermal dysplasia

We have investigated a fragment of the regulatory region of the EDA gene in a patient with clinical symptoms of anhidrotic ectodermal dysplasia (EDA), whose DNA sequence of exon 1 was normal. The single-strand conformation polymorphism (SSCP) analysis of PCR-amplified fragments of the regulatory region of the EDA gene suggested a mutation localized within the fragment extending from nucleotide -571 to -182 upstream of the 5' end of the cDNA. Sequence analysis of this fragment documented an additional adenine in position -452, located 32 nucleotides upstream from the response element HK-1, a target for transcription factor LEF-1, involved in the differentiation of tissues of ectodermal and mesodermal origin. We postulate that this mutation might interfere with the transcription process of the EDA gene and might be responsible, at least in part, for the clinical symptoms of anhidrotic ectodermal dysplasia.

Regulation of 11beta-hydroxysteroid dehydrogenase type II in rat adrenocortical cells

The regulation of 11beta-hydroxysteroid dehydrogenase type II (11beta-HSD2) gene expression was studied in primary cultures of rat adrenocortical cells. The protein kinase A (PKA) pathway agonists forskolin, dibutyryl cAMP and ACTH caused a 5-10 fold increase in 11beta-HSD2 mRNA as determined by semiquantitative PCR. The effect of forskolin could be partially inhibited by the addition of the phorbol ester TPA, an activator of the protein kinase C (PKC) pathway. The increase in mRNA encoding 11beta-HSD2 was accompanied by increased synthesis of 11beta-HSD2 as measured by immunoprecipitation of labeled protein. It is concluded that both the PKA and PKC pathways are involved in the regulation of rat adrenal 11beta-HSD2 gene expression.

Typical hormonal profiles are accompanied by increased immunoreactivity of theca folliculi steroid 17 alpha-hydroxylase P450 in polycystic ovary syndrome

The localisation and expression of steroid 17 alpha-hydroxylase had been studied in ovaries obtained from 40 patients in whom polycystic ovary syndrome (PCO) was diagnosed, and in 15 normal ovaries. In patients, elevated serum LH and testosterone and normal FSH, prolactin and dehydroepiandrosterone levels were recorded. Serum oestradiol concentration was slightly decreased. Immunohistochemical staining with the use of antibody directed against human cytochrome P450c17 (CYP17) revealed that in polycystic as well as in normal ovaries, steroid 17 alpha-hydroxylase is localised mainly in the thecal cells of atretic follicles and in the interstitial cells of the stroma. Greater intensity of the immunohistochemical reaction in the polycystic ovaries than in normal controls, indicates a higher concentration of CYP17 and suggests increased expression of steroid 17 alpha-hydroxylase. It is postulated that the increased expression of ovarian steroid 17 alpha-hydroxylase is an important contributory factor in the pathogenesis of PCO.

Mutation in the regulatory region of the EDA gene coincides with the symptoms of anhidrotic ectodermal dysplasia

We have investigated a fragment of the regulatory region of the EDA gene in a patient with clinical symptoms of anhidrotic ectodermal dysplasia (EDA), whose DNA sequence of exon 1 was normal. The single-strand conformation polymorphism (SSCP) analysis of PCR-amplified fragments of the regulatory region of the EDA gene suggested a mutation localized within the fragment extending from nucleotide -571 to -182 upstream of the 5' end of the cDNA. Sequence analysis of this fragment documented an additional adenine in position -452, located 32 nucleotides upstream from the response element HK-1, a target for transcription factor LEF-1, involved in the differentiation of tissues of ectodermal and mesodermal origin. We postulate that this mutation might interfere with the transcription process of the EDA gene and might be responsible, at least in part, for the clinical symptoms of anhidrotic ectodermal dysplasia.

High molecular mass dextran sulfate increases expression of HIV-1 coreceptor CCR-5 in macrophage-monocytes in culture

It has been reported that high molecular mass dextran sulfate (HMDS) enhances the infection of monocyte-macrophages by HIV-1. We observed that in monocyte-macrophages maintained in the presence of HMDS the expression of HIV-1 coreceptor CCR-5 was increased approximately 5-fold at the transcriptional level. We postulate that the increased expression of CCR-5 might be responsible for HMDS-enhanced infectivity of monocyte-macrophages by HIV-1.