Gonadal function and ovarian galactose metabolism in classic galactosemia

1989 ◽  
Vol 120 (2) ◽  
pp. 129-133 ◽  
Author(s):  
Francine Ratner Kaufman ◽  
Yan Kang Xu ◽  
Won G. Ng ◽  
Paul D. Silva ◽  
Rogerio A. Lobo ◽  
...  

Abstract. Evaluation of ovarian steroid secretion, histologic examination of ovarian tissue, and incubation studies with radiolabelled galactose in ovarian tissue slices were performed in a 21-year-old woman with galactosemia and incipient ovarian failure. After exogenous gonadotropin administration in an attempt to achieve fertility, there was no evidence of ovulation by ultrasound; estrogen and androgen production were deficient indicating ovarian unresponsiveness. Histologic examination of the ovary revealed that the ovarian stroma had an increase in fibrous tissue and that a few hyalinized atretic follicles were present with no intermediate or evolving Graffian follicles. After incubation with galactose-l-14C, there was absence of labelled CO2 production and only labelled galactose-l-phosphate was identified as compared to controls in which several labelled intermediates could be seen. The incorporation of galactose into the TCA-insoluble fraction was drastically reduced in the patient compared to controls, suggesting that there may be a deficiency of ovarian galactose-containing glycolipids, glycoproteins and mucopolysaccharides in the galactosemic ovary. Deficiency in the production of galactose containing compounds, or galactose-phosphate accumulation or both, may lead to the development of hypergonadotropic hypogonadism seen in women with galactosemia.

2021 ◽  
Vol 11 (2) ◽  
pp. 75 ◽  
Author(s):  
Britt Delnoy ◽  
Ana I. Coelho ◽  
Maria Estela Rubio-Gozalbo

Type I (classic) galactosemia, galactose 1-phosphate uridylyltransferase (GALT)-deficiency is a hereditary disorder of galactose metabolism. The current therapeutic standard of care, a galactose-restricted diet, is effective in treating neonatal complications but is inadequate in preventing burdensome complications. The development of several animal models of classic galactosemia that (partly) mimic the biochemical and clinical phenotypes and the resolution of the crystal structure of GALT have provided important insights; however, precise pathophysiology remains to be elucidated. Novel therapeutic approaches currently being explored focus on several of the pathogenic factors that have been described, aiming to (i) restore GALT activity, (ii) influence the cascade of events and (iii) address the clinical picture. This review attempts to provide an overview on the latest advancements in therapy approaches.


1960 ◽  
Vol 38 (1) ◽  
pp. 1167-1172
Author(s):  
Thomas Sandor ◽  
André Lanthier

Surviving human ovarian slices were incubated with 17α-hydroxyprogesterone in a Krebs–Ringer phosphate medium (pH 7.4), at 37 °C under an oxygen atmosphere. The substrate was partially transformed to two steroid glycols, designated as X1and X2. Chromatographic mobility studies, derivatization, and spectra in 95% ethanol and in concentrated sulphuric acid suggested that X1might be identical with Δ4-pregnene-17α,20α-diol-3-one, and X2with Δ4-pregnene-17α,20β-diol-3-one. Synthetic Δ4-pregnene-17α,20β-diol-3-one was prepared from 17α-hydroxyprogesterone. It was found identical with X2by the above-mentioned criteria.In addition to normal human ovarian tissue, slices of human Stein–Leventhal type ovaries were also incubated with the precursor and the transformation rates to X1and X2calculated for both types of tissues.Experiments were performed using as substrate Δ5-pregnene-3β-ol-20-one and progesterone in order to study the reaction with biosynthetic 17α-hydroxyprogesterone. The transformation to X1and X2seemed to follow the same course as with synthetic 17α-hydroxyprogesterone.


Animals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1065 ◽  
Author(s):  
Janice M. V. Vilela ◽  
Ellen C. R. Leonel ◽  
Liudimila P. Gonçalves ◽  
Raísa E. G. Paiva ◽  
Rodrigo S. Amaral ◽  
...  

The aim of this study was to assess a slow-freezing protocol of cat ovarian tissue cryopreservation using autotransplantation. Four adult queens were ovariohysterectomized and the ovaries were fragmented and cryopreserved. After one week, the grafts were thawed and autografted to the subcutaneous tissue of the dorsal neck of each queen, then randomly removed after 7, 14, 28, 49, and 63 days after transplantation. Percentages of morphologically normal primordial and growing follicles (MNFs) were 88% and 97%, respectively, in fresh tissue samples (fresh controls), and 74% and 100%, respectively, immediately after thawing (cryo D0). No MNFs were found after 49 days of transplantation. In both fresh control and cryo D0 fragments, granulosa cells were frequently in proliferation. Two morphologically normal antral follicles were detected in one queen on Day 28 post-transplantation. Connective tissue fibers increased, suggesting replacement of active ovarian cortex by fibrous tissue. Tissue vascularization was observed at 7 days after grafting, and wide blood vessels were clearly visible on Days 49 and 63. In conclusion, although follicular survival was low after cryopreservation and grafting of cat ovarian tissue, follicles were able to develop up to the antral stage, which is an encouraging outcome.


2018 ◽  
Vol 3 (2) ◽  
pp. 222-230 ◽  
Author(s):  
Tatiana Yuzyuk ◽  
Andrew R Wilson ◽  
Rong Mao ◽  
Marzia Pasquali

Abstract Background Classic galactosemia is an inherited disorder of galactose metabolism caused by the impaired activity of galactose-1-phosphate uridyltransferase (GALT). Untreated galactosemia is life-threatening; however, early dietary intervention prevents mortality and reduces morbidity associated with this disease. The diagnosis of galactosemia includes the measurement of GALT activity in red blood cells (RBC) and GALT gene analysis. In this study, we evaluate GALT activity in different genotypes using the results of combined biochemical and molecular testing in 927 samples. Methods GALT activity in RBC was measured by LC-MS/MS. The analysis of the GALT gene was performed by targeted gene analysis and/or full gene sequencing. Samples were assigned based on the presence of pathogenic (G) or Duarte 2 (D) variants, or their absence (Neg), to G/G, D/G, G/Neg, D/D, D/Neg, and Neg/Neg genotypes. Finite mixture models were applied to investigate distributions of GALT activities in these genotypes. The reference ranges were determined using the central 95% of values of GALT activities. Results The ranges of GALT activity in G/G, D/G, G/Neg, D/D, D/Neg, and Neg/Neg genotypes are 0.0 to 0.7 μmol·h−1 gHb−1, 3.1 to 7.8 μmol·h−1 gHb−1, 6.5 to 16.2 μmol·h−1 gHb−1, 6.4 to 16.5 μmol·h−1 gHb−1, 12.0 to 24.0 μmol·h−1 gHb−1, and 19.4 to 33.4 μmol·h−1 gHb−1, respectively. Conclusions The GALT activity ranges established in this study are in agreement with the expected impact of the genotype on the enzymatic activity. Molecular findings should be interpreted in view of biochemical results to confirm genotype–phenotype correlation.


1988 ◽  
Vol 15 (3) ◽  
pp. 377 ◽  
Author(s):  
TD Ugalde ◽  
DJ Chalmers ◽  
PH Jerie

Acid invertase (β-fructofuranosidase, EC 3.2.1.26) was extracted from peach mesocarp (Prunus persica (L.) Batsch) using a range of extraction conditions. The enzyme always was attached to insoluble particles in the crude homogenate and was bound by a mechanism that could not have arisen during extraction. The activity in the insoluble fraction made up (essentially) all of the total activity extracted from the tissue and was the same as the activity shown by whole tissue slices placed directly into the assay solution. These results demonstrate that most of the acid invertase in developing peach mesocarp is located outside the cell. The amount of this enzyme, as measured in vitro, did not change during development at times when the rate of dry matter increase was changing rapidly. Either the action of intercellular invertase is not associated with the control of dry matter accumulation in peach mesocarp, or control is effected through activity of the enzyme in vivo, not its synthesis or degradation.


Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 607 ◽  
Author(s):  
Verena Janes ◽  
Simona Grabany ◽  
Julien Delbrouck ◽  
Stephane P. Vincent ◽  
Johannes Gottschalk ◽  
...  

Genetic defects of human galactose-1-phosphate uridyltransferase (hGALT) and the partial loss of enzyme function result in an altered galactose metabolism with serious long-term developmental impairment of organs in classic galactosemia patients. In search for cellular pathomechanisms induced by the stressor galactose, we looked for ways to induce metabolically a galactosemia-like phenotype by hGALT inhibition in HEK293 cells. In kinetic studies, we provide evidence for 2-fluorinated galactose-1-phosphate (F-Gal-1-P) to competitively inhibit recombinant hGALT with a KI of 0.9 mM. Contrasting with hepatic cells, no alterations of N-glycoprofiles in MIG (metabolic induction of galactosemia)-HEK293 cells were revealed for an inducible secretory netrin-1 probe by MALDI-MS. Differential fluorescence-activated cell sorting demonstrated reduced surface expression of N-glycosylated CD109, EGFR, DPP4, and rhMUC1. Membrane raft proteomes exhibited dramatic alterations pointing to an affection of the unfolded protein response, and of targeted protein traffick. Most prominent, a negative regulation of oxidative stress was revealed presumably as a response to a NADPH pool depletion during reduction of Gal/F-Gal. Cellular perturbations induced by fluorinated galactoses in normal epithelial cells resemble proteomic changes revealed for galactosemic fibroblasts. In conclusion, the metabolic induction of galactosemia-like phenotypes in healthy epithelial/neuronal cells could support studies on the molecular pathomechanisms in classic galactosemia, in particular under conditions of low galactose stress and residual GALT activity.


2018 ◽  
Vol 31 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Danijela Petković Ramadža ◽  
Vladimir Sarnavka ◽  
Jurica Vuković ◽  
Ksenija Fumić ◽  
Vjekoslav Krželj ◽  
...  

AbstractBackground:Classic galactosemia is an autosomal recessive disorder of galactose metabolism caused by severely decreased activity of galactose-1-phosphate uridylyltransferase (GALT) due to pathogenic mutations in theGALTgene. To date more than 330 mutations have been described, with p.Q188R and p.K285N being the most common in Caucasian populations. Although acute manifestations can be fully avoided by a galactose-restricted diet, chronic complications, such as neurological ones, cannot be prevented in a significant number of patients despite compliance with the dietary treatment.Methods:A cohort of 16 galactosemic Croatian patients, including one pair of siblings, was studied. Molecular characterization was performed by direct sequence analysis of theGALTgene.Results:Sixteen patients were analyzed and only four different mutations were detected. As expected, p.Q188R and p.K285N were common, accounting for 40% and 37% of unrelated alleles, respectively. The third mutation accounting for 20% of mutant alleles was p.R123X causing a premature stop codon, is thus considered to be severe, which is in accordance with the phenotype presented by the homozygous patient described here. The fourth mutation p.E271D was found in a single allele. More than half of our patients manifested some chronic neurological complications.Conclusions:This is the first report on mutational and phenotypic spectra of classic galactosemia in Croatia that expands the knowledge on the mutational map of theGALTgene across Europe and reveals the genetic homogeneity of the Croatian population.


2021 ◽  
Author(s):  
Isabelle Flechtner ◽  
Magali Viaud ◽  
Dulanjalee Kariyawasam ◽  
Marie Perrissin-Fabert ◽  
Maud Bidet ◽  
...  

Classic galactosemia is a rare inborn error of galactose metabolism with a birth prevalence of about 1/30 000-60 000. Long-term complications occurring despite dietary treatment consist of premature ovarian insufficiency (POI) and neurodevelopmental impairments. We performed with the French Reference Centers for Rare Diseases a multisite collaborative questionnaire survey for classic galactosemic patients. Its primary objective was to assess their puberty, pregnancy, gonadotrop axis, and pelvic morphology by ultrasound The secondary objective was to determine predictive factors for potent pregnancy without oocyte donation. Completed questionnaires from 103 patients, 56 females (median age, 19 years [5-52 years]) and 47 males (median age, 19 years [3-45 years]), were analyzed. Among the 45 females older than 11 years old, mean age for breast development first stage was 12 years; spontaneous menarche occurred in 25 females at a mean age of 14.6 years. After puberty, 60% of females had irregular menstrual cycles and 50% experienced amenorrhea at a median age of 30 years [15;42]. All age-groups confounded, FSH was above normal range for 65% of the patients, anti-Müllerian hormone and inhibin B were below the normal range according to age, and the ovaries were small with few or no follicles detected. Among the 5 females who sought to conceive, 4 had pregnancies. Among the 47 males, 1 had cryptorchidism, all have normal testicular function and none had tried to conceive. Thus, spontaneous puberty and POI are both common in this population. Spontaneous menarche seems to be the best predictive factor for successful spontaneous pregnancy.


1960 ◽  
Vol 38 (10) ◽  
pp. 1167-1172 ◽  
Author(s):  
Thomas Sandor ◽  
André Lanthier

Surviving human ovarian slices were incubated with 17α-hydroxyprogesterone in a Krebs–Ringer phosphate medium (pH 7.4), at 37 °C under an oxygen atmosphere. The substrate was partially transformed to two steroid glycols, designated as X1and X2. Chromatographic mobility studies, derivatization, and spectra in 95% ethanol and in concentrated sulphuric acid suggested that X1might be identical with Δ4-pregnene-17α,20α-diol-3-one, and X2with Δ4-pregnene-17α,20β-diol-3-one. Synthetic Δ4-pregnene-17α,20β-diol-3-one was prepared from 17α-hydroxyprogesterone. It was found identical with X2by the above-mentioned criteria.In addition to normal human ovarian tissue, slices of human Stein–Leventhal type ovaries were also incubated with the precursor and the transformation rates to X1and X2calculated for both types of tissues.Experiments were performed using as substrate Δ5-pregnene-3β-ol-20-one and progesterone in order to study the reaction with biosynthetic 17α-hydroxyprogesterone. The transformation to X1and X2seemed to follow the same course as with synthetic 17α-hydroxyprogesterone.


2019 ◽  
Vol 43 (3) ◽  
pp. 518-528 ◽  
Author(s):  
Shauna A. Rasmussen ◽  
Jennifer M. I. Daenzer ◽  
Jessica A. MacWilliams ◽  
S. Taylor Head ◽  
Martine B. Williams ◽  
...  

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