Hipogonadyzm hipogonadotropowy u rodzeństwa z mutacją w genie receptora dla GnRH

Hypogonadotropic hypogonadism (HH) is characterised by delayed puberty and infertility. Congenital HH comprises Kallmann syndrome with hypo-/anosmia and idiopathic HH (IHH). The genetic origin remains unknown in most cases, but the defective GnRH receptor gene (GNRHR) accounts for a considerable proportion of IHH. Here we describe a pair of siblings diagnosed with IHH. Aged 17 years, the boy was referred because of short stature (162 cm) and overweight (62.5 kg). He presented no signs of puberty, bone age of 14.5 years and insulin resistance. His sister, aged 16 years, also displayed delayed puberty. She was 166 cm tall and weighed 52 kg; her bone age was 12.5 years. Pelvic ultrasonography showed an infantile uterus and fibrous ovaries. In both siblings, serum gonadotropins were extremely low, and non-responsive to GnRH. Testosterone (1.38 nmol/l) and IGF1 (273 ng/ml) were decreased in the boy, although the girl did not present IFG1 deficiency. Her serum oestradiol was 10 pg/ml. MRIs of the hypothalamo-pituitary region and olfactory bulbs revealed them to be normal. The patients’ sense of smell was unaltered. Their parents appeared to be first degree cousins. Considering the clinical data and potentially autosomal recessive HH transmission, the GNRHR gene was screened. The siblings turned out to be homozygous for the G416A transition, which had previously been identified in other HH individuals. The parents were heterozygous mutation carriers. The proband, moderately responding to LH, was started on low dose testosterone replacement, and his sister on transdermal oestradiol. Molecular data indicative of GnRH resistance could guide their future therapy should they desire fertility restoration. Further observations of the male patient may provide insights into androgen’s influence on body mass, growth and insulin sensitivity. (Pol J Endocrinol 2011; 62 (3): 264–267)Hipogonadyzm hipogonadotropowy (HH) charakteryzuje się opóźnionym dojrzewaniem i bezpłodnością. Wrodzony HH obejmuje zespół Kallamana z hipo-/anosmią oraz przypadki idiopatyczne (IHH). Podłoże genetyczne choroby pozostaje zazwyczaj niejasne, choć defekty genu receptora dla GnRH (GNRHR) odpowiadają za istotną część przypadków. W pracy zaprezentowano opis pary rodzeństwa z rozpoznanym IHH. W wieku 17 lat u chłopca przeprowadzono konsultację z powodu niskorosłości (162 cm) i nadwagi (62,5 kg). Badania wykazały brak dojrzewania płciowego, wiek kostny oceniono na 14,5 roku oraz stwierdzono insulinooporność. U 16-letniej siostry również występowało opóźnione dojrzewanie. Chora miała 166 cm wzrostu, ważyła 52 kg; wiek kostny oceniono na 12,5 roku. Badanie ultrasonograficzne wykazało obecność dziecięcej macicy i włóknistych struktur jajników. U obojga rodzeństwa stwierdzono niskie stężenia gonadotropin w surowicy, bez reakcji na GnRH. Stężenie testosteronu (1,38 nmol/l) oraz IGF1 (273 ng/ml) były obniżone u chłopca, podczas gdy u dziewczynki nie wykazano niedoboru IGF1. Stężenie estradiolu w jej surowicy wynosiło 10 pg/ml. U obojga rezonans magnetyczny nie wykazał patologii okolicy podwzgórzowo-przysadkowej ani opuszek węchowych. Poczucie węchu nie było zaburzone. Rodzice dzieci okazali się kuzynostwem pierwszego stopnia. Biorąc pod uwagę dane kliniczne oraz prawdopodobne autosomalne recesywne dziedziczenie HH, do badań molekularnych wybrano gen GNRHR. U rodzeństwa wykryto homozygotyczną tranzycję G416A, wcześniej opisywaną u innych chorych. U rodziców wykazano heterozygotyczne nosicielstwo mutacji. U probanda, wobec słabej reakcji na LH, włączono substytucję niskimi dawkami testosteronu, a u jego siostry — przezskórny preparat estradiolu. Z uwagi na oporność na GnRH wyniki badań molekularnych mogą wspomóc przyszłe decyzje terapeutyczne w przypadku prób indukcji gametogenezy. Dalsza obserwacja chłopca może dostarczyć danych na temat wpływu androgenów na skład masy ciała, wzrastanie oraz insulinowrażliwość. (Endokrynol Pol 2011; 62 (3): 264–267

Brak związku polimorfizmów genu HSD11B1 z otyłością i cechami zespołu metabolicznego u polskich dzieci i młodzieży

Introduction. Obesity and its related disorders, clustered into metabolic syndrome (MetS), are increasingly diagnosed in children and adolescents. Clinical features, which define MetS are also encountered in patients with glucocorticoid excess. Since no evident hypercortisolaemia was detected in obesity and MetS, investigations turned to the local modulators of cortisol action. 11b-hydroxysteroid dehydrogenase type 1, encoded by HSD11B1 gene, controls tissue availability of cortisol by its regeneration from inert cortisone. Changes in HSD11B1 expression and enzyme activity may be influenced by its sequence variants and seem implicated in MetS pathogenesis. Our study was designed to evaluate plausible association of the HSD11B1 polymorphisms with early-onset obesity and features of MetS in Polish children and adolescents. Material and methods. The study comprised of 258 obese children (136 females), aged 12.3 ± 3.6 years, with excessive body mass lasting 7.1 ± 3.8 years. Anthropometric and blood pressure measurements, baseline biochemical analyses and oral glucose tolerance test were performed in all participants. Genotyping of the HSD11B1 variants rs12086634, rs846910, rs4844880, and rs3753519 was conducted in obese youth and compared with 568 lean blood donors. Results. Mean relative body mass index in obese cohort was 164.7 ± 27.1%. Hypertension was detected in 12.4%, impaired fasting glucose in 8.9%, impaired glucose tolerance in 10.8%, diabetes in 2.7%, and dyslipidemia in 31.4% children and adolescents. None of the studied HSD11B1 polymorphisms dis­played significant difference in frequency between obese and lean individuals. MetS was diagnosed in 27.6% of 203 patients with obesity aged 10–18 years. Further genotype-stratified analyses of relationship between HSD11B1 variants and particular features of MetS did not confirm increased susceptibility to develop early-onset hyperglycaemia, dyslipidaemia and hypertension in carriers of specific genotypes at rs4844880, rs846910, rs3753519, and rs12086634 (p ≥ 0.05 in all tests). Conclusion. Our study does not support the implication of the HSD11B1 polymorphisms in early-onset obesity and other features of MetS.  Wstęp. Otyłość i związane z nią zaburzenia wchodzące w skład zespołu metabolicznego (MetS) są coraz częś­ciej rozpoznawane u dzieci i młodzieży. Cechy kliniczne definiujące MetS stwierdza się również u chorych z nadmiarem glikokortykosteroidów. Ponieważ w oty­łości, jak również w MetS nie wykazano jednoznacznie hiperkortyzolemii, podjęto badania miejscowych modulatorów działania kortyzolu. Dehydrogenaza 11b-hydroksysteroidowa typu 1, kodowana przez gen HSD11B1, kontroluje tkankową dostępność kortyzolu poprzez jego regenerację z nieaktywnego kortyzonu. Indywidualna ekspresja HSD11B1 oraz aktywność enzymu mogą zależeć od polimorficznych wariantów sekwencji genu i wiązać się z patogenezą MetS. Niniej­sze badanie miało na celu ocenę możliwego związku polimorfizmów genu HSD11B1 z wcześnie występującą otyłością i cechami MetS u polskich dzieci i młodzieży. Pacjenci i metody. Badaniem objęto 258 otyłych dzieci (136 dziewczynek) w wieku 12,3 ± 3,6 roku, z nadmierną masą ciała od 7,1 ± 3,8 roku. U wszystkich wykonano pomiary antropometryczne i ocenę ciśnienia tętniczego, podstawowe analizy biochemiczne oraz do­ustny test tolerancji glukozy. Genotypowanie HSD11B1 rs12086634, rs846910, rs4844880 oraz rs3753519 przeprowadzono u otyłych chorych i porównano z 568 zdrowymi szczupłymi dawcami krwi. Wyniki. Średni względny wskaźnik masy ciała w grupie otyłych wynosił 164,7 ± 27,1%. Nadciśnienie wykryto u 12,4%, nieprawidłową glikemię na czczo u 8,9%, upośledzoną tolerancję glukozy u 10,8%, cukrzycę u 2,7%, a dyslipidemię u 31,4% dzieci i młodzieży. Nie wykazano istotnej różnicy częstości występowania żadnego z badanych polimorfizmów genu HSD11B1 między osobami otyłymi i szczupłymi. Zespół metaboliczny rozpoznano u 27,6% z 203 otyłych dzieci w wieku 10–18 lat. Dalsze analizy związku wariantów genu HSD11B1 i cech MetS z podziałem na genotypy nie potwierdziły zwiększonej podatności do rozwoju wczesnej hiperglikemii, dyslipidemia czy nadciśnienia u nosicieli specyficznych genotypów rs4844880, rs846910, rs3753519 lub rs12086634 (p ≥ 0,05 we wszystkich testach). Wniosek. Wyniki przeprowadzonego badania nie potwierdzają związku polimorfizmów genu HSD11B1 z wczesnym rozwojem otyłości ani innych cech zespołu metabolicznego

TMEM244 Is a Long Non-Coding RNA Necessary for CTCL Cell Growth

Transmembrane protein 244 (TMEM244) was annotated to be a member of the TMEM family, which are is a component of cell membranes and is involved in many cellular processes. To date, the expression of the TMEM244 protein has not been experimentally confirmed, and its function has not been clarified. Recently, the expression of the TMEM244 gene was acknowledged to be a diagnostic marker for Sézary syndrome, a rare cutaneous T-cell lymphoma (CTCL). In this study, we aimed to determine the role of the TMEM244 gene in CTCL cells. Two CTCL cell lines were transfected with shRNAs targeting the TMEM244 transcript. The phenotypic effect of TMEM244 knockdown was validated using green fluorescent protein (GFP) growth competition assays and AnnexinV/7AAD staining. Western blot analysis was performed to identify the TMEM244 protein. Our results indicate that TMEM244 is not a protein-coding gene but a long non-coding RNA (lncRNA) that is necessary for the growth of CTCL cells.</p

Mesolimbic dopamine D_{2} receptor plasticity contributes to stress resilience in rats subjected to chronic mild stress

RATIONALE: Few studies have investigated neurobiological and biochemical differences between stress-resilient and stress-vulnerable experimental animals. OBJECTIVES: We investigated alterations in mesolimbic dopamine D(2) receptor density and mRNA expression level in stressed rats at two time points, i.e. after 2 and 5 weeks of chronic mild stress (CMS). METHODS: We used the chronic mild stress paradigm because it is a well-established animal model of depression. Two groups of stressed rats were distinguished during CMS experiments: (1) stress reactive (70 %), which displayed a decrease in the drinking of a palatable sucrose solution during the stress regimen, and (2) stress resilient (30 %), which exhibited an unaltered drinking profile when compared with the unchallenged control group. [(3)H]Domperidone was used as a ligand to label dopamine D(2) receptors, and a mixture of three specific oligonucleotides was used to evaluate dopamine D(2) receptor mRNA changes in various regions of the rat brain. RESULTS: CMS strongly affected the mesolimbic dopamine circuit in stress-resilient group after 2 weeks and stress-reactive group of rats after 5 weeks which exhibited a decrease in the level of dopamine D(2) receptor protein without alterations in D(2) mRNA expression. Stress-resilient animals, but not stress-reactive animals, effectively adapted to the extended stress and coped with it. The increase in D(2) mRNA expression returned the dopamine D(2) receptor density to control levels in stress-resilient rats after 5 weeks of CMS, but not in stress-reactive animals. CONCLUSIONS: These results clearly demonstrate that, despite earlier blunting, the activation of dopamine receptor biosynthesis in the dopamine mesoaccumbens system in stress-resilient rats is involved in active coping with stressful experiences, and it exhibits a delay in time

CRISPR/Cas9 screen for genome-wide interrogation of essential MYC-bound E-boxes in cancer cells

The transcription factor MYC is a proto-oncogene with a well-documented essential role in the pathogenesis and maintenance of several types of cancer. MYC binds to specific E-box sequences in the genome to regulate gene expression in a cell-type- and developmental-stage-specific manner. To date, a combined analysis of essential MYC-bound E-boxes and their downstream target genes important for growth of different types of cancer is missing. In this study, we designed a CRISPR/Cas9 library to destroy E-box sequences in a genome-wide fashion. In parallel, we used the Brunello library to knock out protein-coding genes. We performed high-throughput screens with these libraries in four MYC-dependent cancer cell lines - K562, ST486, HepG2 and MCF7 - which revealed several essential E-boxes and genes. Among them we pinpointed crucial common and cell-type-specific MYC-regulated genes involved in pathways associated with cancer development. Extensive validation of our approach confirmed that E-box disruption affects MYC binding, target-gene expression and cell proliferation in vitro as well as tumor growth in vivo. Our unique, well-validated tool opens new possibilities to gain novel insights into MYC-dependent vulnerabilities in cancer cells.</p

CRISPR/Cas9 screen for genome-wide interrogation of essential MYC-bound E-boxes in cancer cells

The transcription factor MYC is a proto-oncogene with a well-documented essential role in the pathogenesis and maintenance of several types of cancer. MYC binds to specific E-box sequences in the genome to regulate gene expression in a cell-type- and developmental-stage-specific manner. To date, a combined analysis of essential MYC-bound E-boxes and their downstream target genes important for growth of different types of cancer is missing. In this study, we designed a CRISPR/Cas9 library to destroy E-box sequences in a genome-wide fashion. In parallel, we used the Brunello library to knock out protein-coding genes. We performed high-throughput screens with these libraries in four MYC-dependent cancer cell lines - K562, ST486, HepG2 and MCF7 - which revealed several essential E-boxes and genes. Among them we pinpointed crucial common and cell-type-specific MYC-regulated genes involved in pathways associated with cancer development. Extensive validation of our approach confirmed that E-box disruption affects MYC binding, target-gene expression and cell proliferation in vitro as well as tumor growth in vivo. Our unique, well-validated tool opens new possibilities to gain novel insights into MYC-dependent vulnerabilities in cancer cells.</p