| 1. |
- Barbaro, Michela, et al.
(författare)
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Complete androgen insensitivity without Wolffian duct development : the AR-A form of the androgen receptor is not sufficient for male genital development
- 2007
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Ingår i: Clinical Endocrinology. - : Wiley. - 0300-0664 .- 1365-2265. ; 66:6, s. 822-826
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The androgen receptor (AR) is essential for the differentiation of male external and internal genitalia. It is normally present in two forms, a full-length form B and an N-terminal truncated form A with still unknown function. Mutations in the AR gene cause androgen insensitivity syndrome (AIS), which is divided into subgroups according to the degree of undermasculinization. Patients with completely female external genitalia are classified as complete AIS (CAIS). However, a recent study has shown that some CAIS patients have signs of internal male genital differentiation due to missense mutations that show some degree of residual function. OBJECTIVE: We aimed to study the expression of the different forms of the AR in two CAIS patients in relation to the development of male internal genital structures. One patient had a mutation (L7fsX33) that affects only the full-length AR-B form of the AR, whereas the other had a nonsense mutation (Q733X) affecting both isoforms. MEASUREMENTS AND RESULTS: We thoroughly analysed internal genitalia at surgery and by histological examination. No signs of Wolffian duct (WD) development were present in any of the patients. Western blotting of proteins from gonadal and genital skin fibroblasts was performed with AR antibodies directed against different AR epitopes. The N-terminally truncated A form was expressed in normal amounts in the patient with the L7fsX33 mutation while no AR was detected in the other patient. CONCLUSION: The presence of the AR-A form does not seem to be sufficient for WD maintenance and differentiation.
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| 2. |
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| 3. |
- Barbaro, Michela, et al.
(författare)
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Isolated 46,XY gonadal dysgenesis in two sisters caused by a Xp21.2 interstitial duplication containing the DAX1 gene.
- 2007
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 92:8, s. 3305-3313
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Tidskriftsartikel (refereegranskat)abstract
- Context: Testis development is a tightly regulated process that requires an efficient and coordinated spatiotemporal action of many factors, and it has been shown that several genes involved in gonadal development exert a dosage effect. Chromosomal imbalances have been reported in several patients presenting with gonadal dysgenesis as part of severe dysmorphic phenotypes. Results: We screened for submicroscopic DNA copy number variations in two sisters with an apparent normal 46, XY karyotype and female external genitalia due to gonadal dysgenesis, and in which mutations in known candidate genes had been excluded. By high-resolution tiling bacterial artificial chromosome array comparative genome hybridization, a submicroscopic duplication at Xp21.2 containing DAX1 ( NR0B1) was identified. Using fluorescence in situ hybridization, multiple ligation probe amplification, and PCR, the rearrangement was further characterized. This revealed a 637-kb tandem duplication that in addition to DAX1 includes the four MA-GEB genes, the hypothetical gene CXorf21, GK, and part of the MAP3K7IP3 gene. Sequencing and analysis of the breakpoint boundaries and duplication junction suggest that the duplication originated through a coupled homologous and nonhomologous recombination process. Conclusions: This represents the first duplication on Xp21.2 identified in patients with isolated gonadal dysgenesis because all previously described XY subjects with Xp21 duplications presented with gonadal dysgenesis as part of a more complex phenotype, including mental retardation and/or malformations. Thus, our data support DAX1 as a dosage sensitive gene responsible for gonadal dysgenesis and highlight the importance of considering DAX1 locus duplications in the evaluation of all cases of 46, XY gonadal dysgenesis.
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| 4. |
- Bensing, Sophie, et al.
(författare)
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Pituitary autoantibodies in autoimmune polyendocrine syndrome type 1
- 2007
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 104:3, s. 949-954
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Tidskriftsartikel (refereegranskat)abstract
- Autoimmune polyendocrine syndrome type 1 (APS1) is a rare autosomal recessive disorder caused by mutations in the autoimmune regulator (AIRE) gene. High titer autoantibodies (Aabs) toward intracellular enzymes are a hallmark for APS1 and serve as diagnostic markers and predictors for disease manifestations. In this study, we aimed to identify pituitary autoantigens in patients with APS1. A pituitary cDNA expression library was screened with APS1 sera and a tudor domain containing protein 6 (TDRD6) cDNA clone was isolated. Positive immunoreactivity against in vitro translated TDRD6 fragments was shown in 42/86 (49%) APS1 patients but not in patients with other autoimmune diseases or in healthy controls. By using immunohistochemistry, sera from 3/6 APS1 patients with growth hormone (GH) deficiency showed immunostaining of a small number of guinea pig anterior pituitary cells, and 40-50% of these cells were GH-positive. No such immunostaining was seen with sera from healthy controls. The APS1 Aab-positive, GH-negative cells may represent a novel subpopulation of anterior pituitary cells. In addition, 4/6 patient sera showed staining of a fiber-plexus in the pituitary intermediate lobe recognizing enzymes of monoamine and GABA synthesis. Thus, we have identified TDRD6 as a major autoantigen in APS1 patients and shown that several sera from GH-deficient patients stain specific cell populations and nerves in the pituitary gland.
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| 5. |
- Filograna, Roberta, et al.
(författare)
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PARKIN is not required to sustain OXPHOS function in adult mammalian tissues
- 2024
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Ingår i: npj Parkinson's Disease. - : Springer Nature. - 2373-8057. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Loss-of-function variants in the PRKN gene encoding the ubiquitin E3 ligase PARKIN cause autosomal recessive early-onset Parkinson’s disease (PD). Extensive in vitro and in vivo studies have reported that PARKIN is involved in multiple pathways of mitochondrial quality control, including mitochondrial degradation and biogenesis. However, these findings are surrounded by substantial controversy due to conflicting experimental data. In addition, the existing PARKIN-deficient mouse models have failed to faithfully recapitulate PD phenotypes. Therefore, we have investigated the mitochondrial role of PARKIN during ageing and in response to stress by employing a series of conditional Parkin knockout mice. We report that PARKIN loss does not affect oxidative phosphorylation (OXPHOS) capacity and mitochondrial DNA (mtDNA) levels in the brain, heart, and skeletal muscle of aged mice. We also demonstrate that PARKIN deficiency does not exacerbate the brain defects and the pro-inflammatory phenotype observed in mice carrying high levels of mtDNA mutations. To rule out compensatory mechanisms activated during embryonic development of Parkin-deficient mice, we generated a mouse model where loss of PARKIN was induced in adult dopaminergic (DA) neurons. Surprisingly, also these mice did not show motor impairment or neurodegeneration, and no major transcriptional changes were found in isolated midbrain DA neurons. Finally, we report a patient with compound heterozygous PRKN pathogenic variants that lacks PARKIN and has developed PD. The PARKIN deficiency did not impair OXPHOS activities or induce mitochondrial pathology in skeletal muscle from the patient. Altogether, our results argue that PARKIN is dispensable for OXPHOS function in adult mammalian tissues.
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| 6. |
- Johansson, Peter, 1967, et al.
(författare)
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Didaktiska fördjupningskurser för universitetslärare inom och utom lärarutbildningen.
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- 2010 föreslog Lärarutbildningsnämnden (LUN) ett projekt kallat Didaktiska fördjupningskurser för universitetslärare inom och utom lärarutbildningen, vilket skulle utföras inom ramen för PIL:s högskolepedagogiska utvecklingsverksamhet. Bakgrunden till projektet ligger i Göteborgs universitets vision om kompletta akademiska miljöer. Lärarutbildningen, som är en mycket decentraliserad utbildning, har dock mycket begränsade möjligheter att skapa en sådan miljö. Den fakultetsgemensamma forskarskolan Centrum för utbildningsvetenskap och lärarforskning (CUL) är en del av en långsiktig strategi för att skapa en komplett miljö. Vidare har LUN konstaterat att didaktiska fördjupningskurser för lärarutbildare kan vara ett annat sätt att hantera ovanstående problematik genom att skapa en gemensam högskoledidaktisk grund för lärarutbildarna på GU. Projektförslaget hade som inriktning att utveckla två högskoledidaktiska fördjupningskurser om 7,5 högskolepoäng (hp) vardera. Den första kursen skulle vara av mer allmän högskoledidaktisk karaktär och den andra kursen skulle vara riktad mot de av GU:s lärare som medverkar inom lärarprogrammen. En arbetsgrupp tillsattes för att genomföra projektet under hösten 2011. Resultatet av detta arbete är förslag till tre kursplaner (se bilaga 1, 2 och 3) om 5 hp vardera inom fältet högskolepedagogik. Dessa kurser syftar till att bygga på, fördjupa och utveckla de kunskaper och färdigheter som lärare vid GU tillägnat sig inom ramen för befintliga kurser i grundläggande högskolepedagogik som ges av PIL (HPE100-serien). Den första kursen – Allmän högskoledidaktik, 5 hp – fokuserar på grundläggande didaktiska frågor med fokus på begreppet användbarhet. Den andra kursen – Ämnesdidaktik för lärarutbildare, 5 hp – fokuserar på de interna och externa aspekter av samverkan som karaktäriserar lärarutbildningen. Den tredje kursen - Fördjupningsarbete i högskoledidaktik, 5 hp – syftar till att kursdeltagaren inom ramen för ett självständigt arbete ska utforska lärarutbildningens dubbla konstnärliga/vetenskapliga grund i relation till det egna ämnes-/kunskapsfältet. Kursernas övergripande mål är att stärka en formell och reell didaktisk kompetensutveckling av GU:s lärarkår och förväntas därigenom bidra till en ökad utbildningskvalitet inom Göteborgs universitet i allmänhet och för lärarprogrammen i synnerhet.
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| 7. |
- Johansson, Susanne, 1977-
(författare)
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Design and Synthesis of Sialic Acid Conjugates as Inhibitors of EKC-causing Adenoviruses
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The combat against viral diseases has been, and still is, a major challenge in the field of drug development. Viruses are intracellular parasites that use the host cell ma-chinery for their replication and release. Therefore it is difficult to target and destroy the viral particle without disturbing the essential functions of the host cell. This thesis describes studies towards antiviral agents targeting adenovirus type 37 (Ad37), which causes the severe ocular infection epidemic keratoconjunctivitis (EKC). Cell surface oligosaccharides serve as cellular receptors for many pathogens, including viruses and bacteria. For EKC-causing adenoviruses, cell surface oligo-saccharides with terminal sialic acid have recently been shown to be critical for their attachment to and infection of host cells. The work in this thesis support these re-sults and identifies the minimal binding epitope for viral recognition. As carbo-hydrate–protein interactions in general, the sialic acid–Ad37 interaction is very weak. Nature overcomes this problem and vastly improves the binding affinity by presenting the carbohydrates in a multivalent fashion. Adenoviruses interact with their cellular receptors via multiple fiber proteins, whereby it is likely that the ideal inhibitor of adenoviral infections should be multivalent. This thesis includes design and synthesis of multivalent sialic acid glycoconjugates that mimic the structure of the cellular receptor in order to inhibit adenoviral attachment to and infection of human corneal epithelial (HCE) cells. Synthetic routes to three different classes of sialic acid conjugates, i.e. derivatives of sialic acid, 3’-sialyllactose and N-acyl modified sialic acids, and their multivalent counterparts on human serum albumine (HSA) have been developed. Evaluation of these conjugates in cell binding and cell infectivity assays revealed that they are effective as inhibitors. Moreover the results verify the hypothesis of the multivalency effect and clearly shows that the power of inhibition is significantly increased with higher orders of valency. Potential inhibi-tors could easily be transferred to the eye using a salve or eye drops, and thereby they would escape the metabolic processes of the body, a major drawback of using carbohydrates as drugs. The results herein could therefore be useful in efforts to develop an antiviral drug for treatment of EKC.
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| 8. |
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| 9. |
- Oscarson, Mikael
(författare)
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Genetic polymorphism of human drug metabolising enzymes : structural and functional studies
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There is a pronounced interindividual variability in the levels and activity of many drug metabolising enzymes, which might cause differences in the sensitivity to and the toxicity of many clinically used drugs as well as environmental compounds such as nicotine and precarcinogens. In the present investigation the molecular genetic basis for some of the differences in the CYP2A6, CYP2D6, CYP2E1 and GSTM1 enzymes have been elucidated. Cytochrome P450 2D6 (CYP2D6) exhibits a marked interindividual and interethnic variability, with many Asian and black African populations have a generally reduced CYP2D6 activity compared to Caucasians. In Chinese, who are known to having reduced capacity for metabolism of CYP2D6 substrates, we have identified and characterised the CYP2D6*10 allele. This allele was shown to carry two missense mutations, P34S and S486T, and heterologous expression in COS-1 cells revealed that the P34S substitution yields an unstable enzyme that IS rapidly degraded. Indeed CYP2D6*10 was found to be the most common CYP2D6 allele among Chinese. Among black African populations, it has been shown that the presence of the CYP2D6*17 allele correlates well to reduced in vivo activity. The three missense mutations found in this allele, T107I, R296C and S486T, were introduced in all eight possible combinations into a CYP2D6 cDNA and were expressed in yeast. This revealed that a combination of the T107I and R296C substitutions yielded an enzyme with a 5-fold higher apparent Km for the substrates, whereas no effect was seen when the amino acid substitutions were introduced separately. In a Saudi Arabian population, we found a low frequency of these reduced activity alleles and inactive alleles but an Egli frequency of the CYP2D6 gene duplication which is consistent with earlier phenotyping studies in this population. The expression of ethanol-inducible P450 2E1 (CYP2E1) is also known to exhibit striking interindividual variability. In order to elucidate possible genetic causes for this variation, we screened all exons for mutations using genomic DNA from almost 200 unrelated individuals. Two novel alleles were found, yielding enzymes with the amino add substitutions R76H and V3891, respectively. These alleles were however very rare, implicating a selective pressure for active CYP2E1 enzyme, most likely because of an important endogenous function. Sequencing and characterisation of the 5' flanking region of the CYP2E1 gene revealed however the presence of a polymorphic repeat region, with an allele frequency of 23 % in a Chinese population, but only 1 % in Swedes. This polymorphism might be of importance for interindividual differences in the regulation of the CYP2E1 gene. Cytochrome P450 2A6 (CYP2A6) is the major human nicotine C-oxidase. In fact, data has been presented where a correlation was seen between the number of defective CYP2A6*2 and CYP2A6*3 alleles in an individual and the risk of becoming a smoker as well as the number of cigarettes being smoked. The method used for CYP2A6 genotyping has, however, been found to give erroneous results with respect to the coumarin hydroxylase phenotype, a probe drug for the CYP2A6 enzyme. Improved genotyping methods were developed which could correctly predict the CYP2A6 phenotype. We could not, however, detect any CYP2A6*3 alleles in contrast to the 2-28 % previously reported and propose that a previously unknown common gene conversion event in the 3' flanking region of the CYP2A6 gene is the reason for this discrepancy. Furthermore, we found that the CYP2A6 gene deletion was due to an unequal cross-over event between the CYP2A6 gene and the related CYP2A7 gene. A PCR-based genotyping method was developed which showed a frequency of the deletion allele to be 15 % in a Chinese population, but only 1 % in Europeans. Finally, the molecular mechanism behind the ultrarapid glutathione S-transferase M1 (GSTM1) activity found in certain individuals was studied. Southern blotting and PCR analysis revealed a novel GSTM1 allele with a duplication of the active GSTM1 gene, which most likely occurred through an unequal cross-over event. A quantitative PCR method was developed which accurately quantified the number of GSTM1 genes. In summary, several novel cytochrome P450 and GSTM1 alleles have been identified and characterised. These are of putative importance for explanation of impaired drug metabolism and possibly for smoking behaviour and genetically determined sensitivity to carcinogens. These findings form a basis for future molecular epidemiological studies and for use in patients as a tool for individualised drug therapy resulting in less side effects and better efficacy.
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