Simvastatin does not normalize very long chain fatty acids in adrenoleukodystrophy mice.

X-linked adrenoleukodystrophy (ALD) is a genetic demyelinating disorder characterized by accumulation of very long chain fatty acid (VLCFA) in tissues. Lovastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, normalizes VLCFA in fibroblasts and plasma from ALD patients. We dietary treated ALD mice with simvastatin, an analog of lovastatin with similar pharmacokinetics and effects on plasma VLCFA in ALD patients at 20 or 60 mg/kg/day for 6-12 weeks. No decrease of VLCFA content was observed in mouse tissues, including the brain. A significant increase of VLCFA was rather observed in the brain of ALD mice at 60 mg/kg/day.

Mutational and protein analysis of patients and heterozygous women with X-linked adrenoleukodystrophy.

X-linked adrenoleukodystrophy (ALD), a neurodegenerative disorder associated with impaired beta-oxidation of very-long-chain fatty acids (VLCFA), is due to mutations in a gene encoding a peroxisomal ATP-binding cassette (ABC) transporter (ALD protein [ALDP]). We analyzed the open reading frame of the ALD gene in 44 French ALD kindred by using SSCP or denaturing gradient-gel electrophoresis and studied the effect of mutations on ALDP by immunocytofluorescence and western blotting of fibroblasts and/or white blood cells. Mutations were detected in 37 of 44 kindreds and were distributed over the whole protein-coding region, with the exception of the C terminus encoded in exon 10. Except for two mutations (delAG1801 and P560L) observed four times each, nearly every ALD family has a different mutation. Twenty-four of 37 mutations were missense mutations leading to amino acid changes located in or close to putative transmembrane segments (TMS 2, 3, 4, and 5), in the EAA-like motif and in the nucleotide fold of the ATP-binding domain of ALDP. Of 38 ALD patients tested, 27 (71%) lacked ALDP immunoreactivity in their fibroblasts and/or white blood cells. More than half of missense mutations studied (11 of 21) resulted in a complete lack of ALDP immunoreactivity, and six missense mutations resulted in decreased ALDP expression. The fibroblasts and/or white blood cells of 15 of 15 heterozygous carrier from ALD kindred with no ALDP showed a mixture of positive- and negative-ALDP immunoreactivity due to X-inactivation. Since 5%-15% of heterozygous women have normal VLCFA levels, the immunodetection of ALDP in white blood cells can be applicable in a majority of ALD kindred, to identify heterozygous women, particularly when the ALD gene mutation has not yet been identified.

Identification of mutations in the putative ATP-binding domain of the adrenoleukodystrophy gene.

The recently identified adrenoleukodystrophy (ALD) gene is predicted to encode a peroxisomal protein of 745 amino acids that includes one domain for ATP-binding, termed nucleotide-binding fold (NBF). To determine whether mutations occur in the putative NBF of ALD protein, we analyzed by denaturing gradient gel electrophoresis (DGGE) exon 6 and 8 that encode most part of this domain in 50 ALD patients. Four amino acid substitutions, three frameshift mutations leading to premature termination signal, and a splicing mutation were identified. These amino acid substitutions occurred at residues highly conserved in other ATP-binding cassette (ABC) proteins. In addition, a nonsense mutation was detected in exon 4.

[Adrenoleukodystrophy: significance for genetic counseling of the determination of very long-chain fatty acids and of molecular biology]. / Adrénoleucodystrophie: intérêt pour le conseil génétique du dosage des AGTLC et de la biologie moléculaire.

Juvenile adrenoleukodystrophy (ADL) is a peroxisomal, X-linked, consistently fatal condition for which no treatment is currently available. Detection of heterozygote females and antenatal diagnosis by determination of very long chain fatty acid levels are therefore mandatory. We report the case of a family with two affected first cousins but six unaffected maternal uncles. Plasma levels confirmed the usual X-linked pattern with transmission by the grandmother and ruled out the hypothesis of delayed adrenomyeloleukodystrophy in the grandfather with heterozygosis of all the daughters. Although all six sons are unaffected, two certainly heterozygote females have normal plasma very long chain fatty acid levels. Heterozygosis in these women was confirmed by family restriction fragment length polymorphism studies (TAQ1) using the St 14 probe whose reliability for the diagnosis of heterozygotes with normal plasma very long chain fatty acid levels has previously been documented.

The red-green visual pigment gene region in adrenoleukodystrophy.

Although recent data established that a specific very-long-chain fatty acyl-CoA synthetase is defective in X-linked adrenoleukodystrophy (ALD), the ALD gene is still unidentified. The ALD locus has been mapped to Xq28, like the red and green color pigment genes. Abnormal color vision has been observed in 12 of 27 patients with adrenomyeloneuropathy (AMN), a milder form of ALD. Furthermore, rearrangements of the color vision gene cluster were found in four of eight ALD kindreds. This led us to propose that a single DNA rearrangement could underlie both ALD and abnormal color vision in these patients. Study of 34 French ALD patients failed to reveal a higher than expected frequency of green/red visual pigment rearrangements 3' to the red/green color vision gene complex. The previous report of such rearrangements was based on small numbers and lack of knowledge that the frequency of "abnormal" color vision arrays on molecular analysis was twice as high as expected on the basis of the frequency of phenotypic color vision defects. The red/green color pigment (R/GCP) region was studied by pulsed-field gel electrophoresis in 14 of these patients, and we did not find any fragment size difference between the patients and normal individuals who have the same number of pigment genes. The R/GCP region was also analyzed in 29 French and seven North American ALD patients by using six genomic DNA probes, isolated from a cosmid walk, that flank the color vision genes. No deletions were found with probes that lie 3' of the green pigment genes. One of the eight previously reported ALD individuals has a long deletion 5' of the red pigment gene, a deletion causing blue cone monochromacy. This finding and the previous findings of a 45% frequency of phenotypic color vision defects in patients with AMN may suggest that the ALD/AMN gene lies 5' to the red pigment gene and that the frequent phenotypic color vision anomalies owe their origin to deleted DNA that includes regulatory genes for color vision. It is possible, however, that phenotypic color vision anomalies in AMN may be phenocopies secondary to retinal or neural involvement by the disease. The single case of blue cone monochromacy may therefore be a fortuitous coincidence of two diseases.

Variations of growth factors in pregnant women during labor and in newborns at delivery.

To study physiological variations in serum growth factors during peripartal period, we have measured levels of a serum growth-promoting activity (thymidine activity, TA) and radioimmunoassayable somatomedin C (Sm-C) during labor in 39 women who delivered spontaneously (group A), by caesarean section (group B) and by legal abortion (LA) (group C). TA values were higher in the group A than in the group B and C, suggesting an important effect of uterine contractions in TA generation. A major role in Sm-C production seems to be played by the length of gestation since Sm-C concentrations were significantly higher in mothers delivered by caesarean section than in LA women. During labor influence of estrogens and progesterone in growth factor production seems unlikely because of the lack of correlation with TA and Sm-C levels. The lower TA values in placental flow than in the capillary blood of newborn suggest that serum growth factors, measured as TA, are produced by the newborn and do not cross through the placenta. These data suggest that the absolute dependence of the fetus on the mother does not preclude instances of fetal autonomy.

[Effect of serum fractions on the incorporation of tritiated thymidine in activated lymphocytes: I. Human serum from normal adult subjects]. / Effet des fractions sériques sur l'incorporation de thymidine tritiée dans le lymphocyte activé: I. Sérum humain provenant de sujets adultes normaux.

Fractionation of normal human adult serum using Centrisart or gel filtration at neutral pH shows that serum thymidine activity, measured as the ability to stimulate the 3H-thymidine uptake into lectin-activated lymphocytes, is represented by several molecular forms distinct from the endogenous Sm-C. The main thymidine activity is found in the 50-70 K range.

Serum thymidine activity and somatomedin-C levels in children and adolescents with Turner's syndrome: effect of chronic estrogen and progestogen replacement therapy.

Turner's syndrome has been used as a model of primary hypogonadism to assess the role of estrogen-progestogen replacement therapy on serum thymidine activity (TA) and somatomedin-C (Sm-C) levels. 33 subjects with gonadal dysgenesis were studied: 10 untreated and 13 treated with estrogen-progestogen combination. In 10 untreated patients serum TA was 1.02 +/- (SEM) 0.04 U/ml and serum Sm-C value was 27.82 +/- 4.14 nmol/l, both similar to those in the age-matched normal children. A positive correlation was found between Sm-C and the bone age (r = 0.891, p less than 0.002). In the 13 treated subjects, the estrogen-progestogen combination as replacement therapy induced a significant increase in Sm-C level (40.52 +/- 4.30 nmol/l, p less than 0.05). No variation was observed for serum thymidine activity between the two groups of subjects.

Effect of the variations of female sex hormones during the menstrual cycle upon serum somatomedin and growth-promoting activity.

Serum growth-promoting activity measured upon lymphocytes, sulfation activity and radioimmunoassayable somatomedin C (Sm-C) levels were measured in sera from women during the menstrual cycle. The data showed that: estradiol, progesterone, LH or FSH added in vitro do not increase the 3H-thymidine uptake into lymphocytes; the serum thymidine activity decreases during the luteal stage of the cycle, and is negatively correlated with the progesterone levels; the sulfation factor and Sm-C levels do not have significant variations during the menstrual cycle, and the GH maximum values are attained during the luteal stage.

PIP: This study investigated variations in thymidine activity, sulfation activity, and radioimmunoassayable somatomedin C levels during the menstrual cycle and the direct effect of female sex hormones on 3H-thymidine incorporation into lymphocytes in vitro. Subjects included 8 healthy women 24-46 years of age from whom a total of 49 venous blood samples were obtained. Estradiol, progesterone, luteinizing hormone, or follicle stimulating hormone added in vitro did not increase 3H-thymidine uptake into lymphocytes. The serum thymidine activity level was observed to decrease during the luteal phase of the menstrual cycle and was negatively correlated with the progesterone levels. The sulfation factor and somatomedin C levels did not have significant variations during the menstrual cycle. Finally, growth hormone maximum values were attained during the luteal phase. The negative correlation of thymidine activity levels with progesterone values suggests that more than one thymidine activity measures all serum factors.

Effects of gonadotrophin-induced elevation of serum testosterone upon somatomedin C levels and serum thymidine activity in children.

3H-thymidine uptake into lectin-activated human lymphocytes allows to measure a growth-stimulating activity of serum, the thymidine activity (TA), which is GH dependent in vivo and related to somatomedins (Sm). In this work, it is shown: that addition of human chorionic gonadotrophin (HCG) or testosterone in vitro does not increase the 3H-thymidine uptake into lymphocytes; that the gonadotrophin-induced elevation of testosterone in children is accompanied by a significant increase of TA and, at a lesser degree, of Sm C; that these two increases are significantly correlated, and that the age-related variation of TA and Sm C after HCG stimulation test are not parallel.