Maternal protein restriction during lactation modulated the expression and activity of rat offspring hepatic CYP1A1, CYP1A2, CYP2B1, CYP2B2, and CYP2E1 during development

Early nutrition plays a long-term role in the predisposition to chronic diseases and influences the metabolism of several drugs. This may happen through cytochromes P450 (CYPs) regulation, which are the main enzymes responsible for the metabolism of xenobiotics. Here, we analyzed the effects of maternal protein restriction (MPR) on the expression and activity of hepatic offspring’s CYPs during 90 days after birth, using Wistar rats as a mammal model. Hepatic CYP1A1, CYP1A2, CYP2B1, CYP2B2 and CYP2E1 mRNA and protein expression, and associated catalytic activities (ECOD, EROD, MROD, BROD, PROD and PNPH) were evaluated in 15-, 30-, 60-, and 90-day-old offspring from dams fed with either a 0% protein (MPR groups) or a standard diet (C groups) during the 10 first days of lactation. Results showed that most CYP genes were induced in 60- and 90-day-old MPR offspring. The inductions detected in MPR60 and MPR90 were of 5.0- and 2.0-fold (CYP1A2), 3.7- and 2.0-fold (CYP2B2) and 9.8- and 5.8– fold (CYP2E1), respectively, and a 3.8-fold increase of CYP2B1 in MPR90. No major alterations were detected in CYP protein expression. The most relevant CYP catalytic activities’ alterations were observed in EROD, BROD and PNPH. Nevertheless, they did not follow the same pattern observed for mRNA expression, except for an induction of EROD in MPR90 (3.5-fold) and of PNPH in MPR60 (2.2-fold). Together, these results suggest that MPR during lactation was capable of altering the expression and activity of the hepatic CYP enzymes evaluated in the offspring along development.

New insights into steroidogenesis in normo- and hyperandrogenic polycystic ovary syndrome patients / Novos aspectos na esteroidogênese em pacientes normo ou hiperandrogênicas com síndrome de ovários policísticos

OBJECTIVE: This study sought to examine corticosteroidogenic enzyme activities in normo- and hyperandrogenic polycystic ovary syndrome (PCOS) patients. SUBJECTS AND METHODS: This cohort study included 81 patients with biochemical hyperandrogenism and 41 patients with normal androgen levels. Enzyme activities were assessed according to the serum steroid product/precursor ratios at baseline and after adrenal stimulation. RESULTS: At baseline, in the delta 4 (Δ4) pathway, hyperandrogenic patients showed greater 17-hydroxylase and 17,20 lyase activities in converting progesterone (P4) into 17-hydroxyprogesterone (17-OHP4) and 17-hydroxypregnenolone (17-OHPE) into androstenedione (A) (p = 0.0005 and p = 0.047, respectively) compared to normoandrogenic patients. In the delta 5 (Δ5) pathway, the 17-hydroxylase and 17,20 lyase enzymes showed similar activities in both groups. Hyperandrogenic patients presented lower 21-hydroxylase, lower 11β-hydroxylase (p = 0.0001), and statistically significant increases in 3β-hydroxysteroid dehydrogenase II (3β-HSDII) activities (p < 0.0001). Following tetracosactrin stimulation, only the 17,20 lyase activity remained up-regulated in the Δ4 pathway (p < 0.0001). CONCLUSION: Hyperandrogenic patients had higher 17,20 lyase activity, both at baseline and after adrenal stimulation. Greater conversion of dehydroepiandrosterone (DHEA) into A with normal conversion of 17-OHPE to 17-OHP4 in hyperandrogenic PCOS patients indicated different levels of 3β-HSDII activity in adrenal cells, and hyperandrogenic patients had lower 11β-hydroxylase and 21-hydroxylase activities.

OBJETIVO: O objetivo deste estudo foi examinar a atividade de enzimas responsáveis pela produção de corticosteroides em pacientes normo e hiperandrogênicas com síndrome de ovários policísticos (SOP). SUJEITOS E MÉTODOS: A coorte estudada incluiu 81 pacientes com hiperandrogenismo bioquímico e 41 pacientes com níveis normais de androgênio. A atividade enzimática foi avaliada de acordo com as proporções de produto/precursor do esteroide sérico, no momento inicial do estudo e depois de estimulação adrenal. RESULTADOS: No momento inicial, na via delta 4 (Δ4), as pacientes hiperandrogênicas mostraram maior atividade da 17-hidroxilase e 17,20 liase na conversão da progesterona (P4) em 17-hidroxiprogesterona (17-OHP4) e na conversão da 17-hidroxipregnenolona (17-OHPE) em androstenediona (A) (p = 0,0005 e p = 0,047, respectivamente) em comparação com pacientes normoandrogênicas. Na via delta 5 (Δ5), a 17-hidroxilase e a 17,20 liase mostraram atividades similares nos dois grupos. As pacientes hiperandrogênicas mostraram menor atividade da 21-hidroxilase, menor atividade da 11β-hidroxilase (p = 0,0001) e aumento estatisticamente significativo na atividade da 3β-hidroxiesteroide desidrogenase II (3β-HSDII) (p < 0.0001). Após a estimulação com tetracosactrin, apenas a atividade da 17,20 liase permaneceu regulada para cima na via Δ4 (p < 0.0001). CONCLUSÃO: As pacientes hiperandrogênicas apresentaram atividade mais alta da 17,20 liase, tanto no momento inicial quanto depois da estimulação adrenal. Maior conversão da desidroepiandrosterona (DHEA) em A com conversão normal da 17-OHPE em 17-OHP4 em pacientes hiperandrogênicas com SOP indica níveis diferentes de atividade da 3β-HSDII em células da adrenal, e pacientes hiperandrogênicas apresentaram menores atividades da 11β-hidroxilase e da 21-hidroxilase.

Mutations in the vitamin D receptor gene in four patients with hereditary 1, 25-dihydroxyvitamin D-resistant rickets / Mutações no gene do receptor de vitamin D em quatro pacientes com raquitismo hereditário resistente a 1, 25-dihydroxyvitamin D

Mutations in the vitamin D receptor (VDR) are associated to the hereditary 1,25-dihydroxivitamin D-resistant rickets. The objectives of this work are: search for mutations in the VDR and analyze their functional consequences in four Brazilian children presented with rickets and alopecia. The coding region of the VDR was amplified by PCR e direct sequenced. We identified three mutations: two patients had the same mutation in exon 7 at aminoacid position 259 (p.Q259E); one patient had a mutation in exon 8 at codon 319 (p.G319V) and another one had a mutation in exon 3 leading to a truncated protein at position 73 (p.R73X). Functional studies of the mutant receptors of fibroblast primary culture, from patients' skin biopsy treated with increasing doses of 1,25(OH)2 vitamin D showed that VDR mutants were unable to be properly activated and presented a reduction in 24-hydroxylase expression level.

Mutações no receptor de vitamina D (VDR) são associadas a raquitismo hereditário resistente a 1,25-dihidroxivitamina D. Os objetivos deste trabalho foram procurar mutações no VDR e analisar suas conseqüências funcionais em quatro pacientes com raquitismo e alopécia. A região codificadora do VDR foi amplificada por PCR e seqüenciada diretamente. Identificamos três mutações: dois pacientes apresentavam a mesma mutação no éxon 7 na posição protéica 259 (p.Q259E); um paciente apresentava uma mutação no éxon 8 no códon 319 (p.G319V) e o outro apresentava uma mutação no exon 3 resultando em uma proteína truncada na posição 73 (p.R73X). O estudo funcional dos receptores mutados nos extratos de culturas de fibroblasto primárias obtidas de biópsia de pele dos pacientes, tratados com doses crescentes de 1,25(OH)2 vitamina D demonstraram que os receptores mutantes não apresentam ativação adequada apresentando expressão reduzida de 24-hidroxilase.