RESUMO
Idiopathic normal pressure hydrocephalus (iNPH) is an enigmatic neurological disorder that develops after age 60 and is characterized by gait difficulty, dementia, and incontinence. Recently, we reported that heterozygous CWH43 deletions may cause iNPH. Here, we identify mutations affecting nine additional genes (AK9, RXFP2, PRKD1, HAVCR1, OTOG, MYO7A, NOTCH1, SPG11, and MYH13) that are statistically enriched among iNPH patients. The encoded proteins are all highly expressed in choroid plexus and ependymal cells, and most have been associated with cilia. Damaging mutations in AK9, which encodes an adenylate kinase, were detected in 9.6% of iNPH patients. Mice homozygous for an iNPH-associated AK9 mutation displayed normal cilia structure and number, but decreased cilia motility and beat frequency, communicating hydrocephalus, and balance impairment. AK9+/- mice displayed normal brain development and behavior until early adulthood, but subsequently developed communicating hydrocephalus. Together, our findings suggest that heterozygous mutations that impair ventricular epithelial function may contribute to iNPH.
Assuntos
Hidrocefalia de Pressão Normal , Hidrocefalia , Humanos , Camundongos , Animais , Adulto , Pessoa de Meia-Idade , Hidrocefalia de Pressão Normal/genética , Hidrocefalia de Pressão Normal/complicações , Hidrocefalia/genética , Encéfalo , Plexo Corióideo , Mutação , ProteínasRESUMO
G protein-coupled receptors (GPCRs) play crucial roles in numerous physiological and pathological processes. Mutations in GPCRs that result in loss of function or alterations in signaling can lead to inherited or acquired diseases. Herein, studying prokineticin receptor 2 (PROKR2), we initially identify distinct interactomes for wild-type (WT) versus a mutant (P290S) PROKR2 that causes hypogonadotropic hypogonadism. We then find that both the WT and mutant PROKR2 are targeted for endoplasmic reticulum (ER)-associated degradation, but the mutant is degraded to a greater extent. Further analysis revealed that both forms can also leave the ER to reach the Golgi. However, whereas most of the WT is further transported to the cell surface, most of the mutant is retrieved to the ER. Thus, the post-ER itinerary plays an important role in distinguishing the ultimate fate of the WT versus the mutant. We have further discovered that this post-ER itinerary reduces ER stress induced by the mutant PROKR2. Moreover, we extend the core findings to another model GPCR. Our findings advance the understanding of disease pathogenesis induced by a mutation at a key residue that is conserved across many GPCRs and thus contributes to a fundamental understanding of the diverse mechanisms used by cellular quality control to accommodate misfolded proteins.
Assuntos
Estresse do Retículo Endoplasmático/fisiologia , Proteostase/fisiologia , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Peptídeos/metabolismo , Animais , Células COS , Membrana Celular/metabolismo , Chlorocebus aethiops , Retículo Endoplasmático/metabolismo , Degradação Associada com o Retículo Endoplasmático , Complexo de Golgi/metabolismo , Células HEK293 , Células HeLa , Humanos , Hipogonadismo/metabolismo , Mutação de Sentido Incorreto/genética , Transporte Proteico/genética , Transporte Proteico/fisiologia , Receptores Acoplados a Proteínas G/genética , Receptores de Peptídeos/genética , Transdução de SinaisRESUMO
Idiopathic normal pressure hydrocephalus (iNPH) is a common neurological disorder that is characterized by enlarged cerebral ventricles, gait difficulty, incontinence, and dementia. iNPH usually develops after the sixth decade of life in previously asymptomatic individuals. We recently reported that loss-of-function deletions in CWH43 lead to the development of iNPH in a subgroup of patients, but how this occurs is poorly understood. Here, we show that deletions in CWH43 decrease expression of the cell adhesion molecule, L1CAM, in the brains of CWH43 mutant mice and in human HeLa cells harboring a CWH43 deletion. Loss-of-function mutations in L1CAM are a common cause of severe neurodevelopmental defects that include congenital X-linked hydrocephalus. Mechanistically, we find that CWH43 deletion leads to decreased N-glycosylation of L1CAM, decreased association of L1CAM with cell membrane lipid microdomains, increased L1CAM cleavage by plasmin, and increased shedding of cleaved L1CAM in the cerebrospinal fluid. CWH43 deletion also decreased L1CAM nuclear translocation, suggesting decreased L1CAM intracellular signaling. Importantly, the increase in L1CAM cleavage occurred primarily in the ventricular and subventricular zones where brain CWH43 is most highly expressed. Thus, CWH43 deletions may contribute to adult-onset iNPH by selectively downregulating L1CAM in the ventricular and subventricular zone.
Assuntos
Pressão do Líquido Cefalorraquidiano , Fibrinolisina/metabolismo , Hidrocefalia/metabolismo , Hidrocefalia/patologia , Proteínas de Membrana/metabolismo , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Animais , Encéfalo/patologia , Regulação para Baixo , Deleção de Genes , Regulação da Expressão Gênica , Células HeLa , Humanos , Lipídeos/química , Imageamento por Ressonância Magnética , Proteínas de Membrana/genética , Camundongos , Molécula L1 de Adesão de Célula Nervosa/genética , Ligação Proteica , Domínios Proteicos , RNARESUMO
Internationally, undergraduate medical education is not currently enabling early career doctors to meet the needs of trans and gender diverse (TGD) people as healthcare consumers. This review outlines inclusion of TGD education in undergraduate medical education more broadly to contextualise curriculum development needs in obstetrics, gynaecology and reproductive medicine in Aotearoa/New Zealand. Limited, and lack of integrated content, teaching capability and current absence of TGD health knowledge as graduate outcomes, compounded by pedagogy (biomedical/binary framing) and more appropriate learning resources are indicators for curricula, and workforce, development.
Assuntos
Educação de Graduação em Medicina , Ginecologia , Obstetrícia , Pessoas Transgênero , Humanos , Ginecologia/educação , Nova Zelândia , Currículo , Obstetrícia/educaçãoRESUMO
Heterozygous mutations affecting FOXJ1, a transcription factor governing multiciliated cell development, have been associated with obstructive hydrocephalus in humans. However, factors that disrupt multiciliated ependymal cell function often cause communicating hydrocephalus, raising questions about whether FOXJ1 mutations cause hydrocephalus primarily by blocking cerebrospinal fluid (CSF) flow or by different mechanisms. Here, we show that heterozygous FOXJ1 mutations are also associated with communicating hydrocephalus in humans and cause communicating hydrocephalus in mice. Disruption of one Foxj1 allele in mice leads to incomplete ependymal cell differentiation and communicating hydrocephalus. Mature ependymal cell number and motile cilia number are decreased, and 12% of motile cilia display abnormal axonemes. We observed decreased microtubule attachment to basal bodies, random localization and orientation of basal body patches, loss of planar cell polarity, and a disruption of unidirectional CSF flow. Thus, heterozygous FOXJ1 mutations impair ventricular multiciliated cell differentiation, thereby causing communicating hydrocephalus. CSF flow obstruction may develop secondarily in some patients harboring FOXJ1 mutations. Heterozygous FOXJ1 mutations impair motile cilia structure and basal body alignment, thereby disrupting CSF flow dynamics and causing communicating hydrocephalus.
Assuntos
Hidrocefalia , Camundongos , Humanos , Animais , Hidrocefalia/genética , Epêndima/metabolismo , Regulação da Expressão Gênica , Mutação/genética , Diferenciação Celular , Cílios/genética , Cílios/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismoRESUMO
BACKGROUND: Rainbow young people (RYP; people of diverse genders, sexualities, and variations in sex characteristics) face barriers accessing primary care, often report negative experiences and the need to educate clinicians on rainbow-specific issues. This study explores general practice staff views and experiences of providing care to RYP. METHODS: Three focus groups were held with staff from 5 general practices in an urban area of Aotearoa New Zealand (25 participants in total). Practices were purposively selected to include some known to be more "rainbow-friendly" seeing larger numbers of RYP and some with no particular focus on RYP. All members of each practice were invited to participate, including administration and reception staff. Focus groups were audio-recorded, transcribed, and analysed in NVivo using inductive thematic analysis. RESULTS: Four main themes were identified: (i) Practice experience, (ii) Feeling awkward, (iii) Knowledge and training, and (iv) Structural barriers. Differences were apparent in health provider knowledge, comfort, and experience in providing care to RYP. Participants identified a lack of knowledge and training and wanted more resources and education. Systems limitations were common (e.g. with IT systems for recording gender) and often contributed to awkward clinical encounters. CONCLUSIONS: Participants recognized shortcomings in their training, knowledge, and level of confidence providing care to RYP and expressed a desire to improve their competency. Further work is needed to identify and trial practical strategies that help improve communication skills, knowledge, and the delivery of more equitable healthcare to RYP.
RESUMO
Little is known about experiences and barriers for trans and non-binary (TGNB) people eligible for cervical screening in Aotearoa New Zealand. AIMS: To identify uptake, barriers and reasons for delaying cervical cancer screening among TGNB people in Aotearoa. MATERIALS AND METHODS: The 2018 Counting Ourselves data on TGNB people assigned female at birth aged 20-69 years who had ever had sex, were analysed to report on experiences of those who were eligible for cervical screening (n = 318). Participants answered questions about whether they had taken part in cervical screening and reasons behind any delays in receiving the test. RESULTS: Trans men were more likely than non-binary participants to report that they did not require cervical screening or were unsure if they needed it. For those who had delayed cervical screening, 30% did so due to feeling worried about how they would be treated as a trans or non-binary person and 35% due to another reason. Other reasons for delay related to general and gender-related discomfort, previous traumatic experiences, anxiety or fear of the test and pain. Material barriers to access included cost and lack of information. CONCLUSIONS: The current cervical screening program in Aotearoa does not consider the needs of TGNB people, leading to delayed and reduced uptake of cervical screening. Health providers require education on the reasons TGNB people delay or avoid cervical screening in order to provide appropriate information and affirmative healthcare environments. The human papillomavirus self-swab may address some of the existing barriers.
Assuntos
Pessoas Transgênero , Transexualidade , Neoplasias do Colo do Útero , Masculino , Recém-Nascido , Humanos , Feminino , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/prevenção & controle , Detecção Precoce de Câncer , Nova ZelândiaRESUMO
BACKGROUND: Past research has established that transgender people experience significant disparities in mental health outcomes and healthcare dissatisfaction compared with cisgender people, but more research is needed on how supportive healthcare interactions relate to the mental health of transgender people. OBJECTIVES: The 2 main aims of our analyses were: (i) to establish the most common negative experiences in healthcare and the most common supportive experiences specifically with primary care doctors for transgender people; and (ii) to examine the association of supportive experiences with mental health variables after controlling for demographic factors. METHODS: Data from the 2018 Counting Ourselves nationwide survey of transgender people were analysed using regression modelling. The 948 participants with a primary care doctor or general practitioner were included in analyses. Participants were aged 14-83 years old (mean 30.20). RESULTS: The most common supportive experiences involved primary care doctors treating transgender people equitably, with competence, and with respect. Participants with more negative healthcare experiences had higher psychological distress as well as higher likelihood of reporting nonsuicidal self-injury and suicidality. Conversely, participants with more experiences of supportive primary care doctors had lower psychological distress and were less likely to have attempted suicide in the past 12 months. CONCLUSION: When transgender people receive supportive care from their primary care providers they experience better mental health, despite ongoing negative healthcare experiences. Future research is needed to confirm ways of supporting positive trajectories of mental health for transgender people but these findings demonstrate the importance of positive aspects of care.
Assuntos
Minorias Sexuais e de Gênero , Pessoas Transgênero , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Saúde Mental , Pessoa de Meia-Idade , Nova Zelândia , Atenção Primária à Saúde , Pessoas Transgênero/psicologia , Adulto JovemRESUMO
Glioblastoma multiforme is the most lethal intrinsic brain tumor. Even with the existing treatment regimen of surgery, radiation, and chemotherapy, the median survival time is only 15-23 months. The invasive nature of this tumor makes its complete removal very difficult, leading to a high recurrence rate of over 90%. Drug delivery to glioblastoma is challenging because of the molecular and cellular heterogeneity of the tumor, its infiltrative nature, and the blood-brain barrier. Understanding the critical characteristics that restrict drug delivery to the tumor is necessary to develop platforms for the enhanced delivery of effective treatments. In this review, we address the impact of tumor invasion, the molecular and cellular heterogeneity of the tumor, and the blood-brain barrier on the delivery and distribution of drugs using potential therapeutic delivery options such as convection-enhanced delivery, controlled release systems, nanomaterial systems, peptide-based systems, and focused ultrasound.
Assuntos
Antineoplásicos , Neoplasias Encefálicas/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Glioblastoma/tratamento farmacológico , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Barreira Hematoencefálica , HumanosRESUMO
BACKGROUND: Excess reactive oxygen species and reactive nitrogen species are implicated in male infertility and impaired spermatogenesis. AIM: To investigate the effect of excess reactive nitrogen species and nitrosative stress on testicular function and the hypothalamic-pituitary-gonadal axis using the S-nitrosoglutathione reductase-null (Gsnor-/-) mouse model. METHODS: Testis size, pup number, and epididymal sperm concentration and motility of Gsnor-/- mice were compared with those of age-matched wild-type (WT) mice. Reproductive hormones testosterone (T), luteinizing hormone (LH), and follicle-stimulating hormone were compared in Gsnor-/- and WT mice. Immunofluorescence for Gsnor-/- and WT testis was performed for 3ß-hydroxysteroid dehydrogenase and luteinizing hormone receptor (LHR) and compared. Human chorionic gonadotropin and gonadotropin-releasing hormone stimulation tests were performed to assess and compare testicular and pituitary functions of Gsnor-/- and WT mice. OUTCOMES: Evaluation of fertility and reproductive hormones in Gsnor-/- vs WT mice. Response of Gsnor-/- and WT mice to human chorionic gonadotropin and gonadotropin-releasing hormone to evaluate LH and T production. RESULTS: Gsnor-/- mice had smaller litters (4.2 vs 8.0 pups per litter; P < .01), smaller testes (0.08 vs 0.09 g; P < .01), and decreased epididymal sperm concentration (69 vs 98 × 106; P < .05) and motility (39% vs 65%; P < .05) compared with WT mice. Serum T (44.8 vs 292.2 ng/dL; P < .05) and LH (0.03 vs 0.74 ng/mL; P = .04) were lower in Gsnor-/- than in WT mice despite similar follicle-stimulating hormone levels (63.98 vs 77.93 ng/mL; P = .20). Immunofluorescence of Gsnor-/- and WT testes showed similar staining of 3ß-hydroxysteroid dehydrogenase and LHR. Human chorionic gonadotropin stimulation of Gsnor-/- mice increased serum T (>1,680 vs >1,680 ng/dL) and gonadotropin-releasing hormone stimulation increased serum LH (6.3 vs 8.9 ng/mL; P = .20) similar to WT mice. CLINICAL TRANSLATION: These findings provide novel insight to a possible mechanism of secondary hypogonadism from increased reactive nitrogen species and excess nitrosative stress. STRENGTHS AND LIMITATIONS: Limitations of this study are its small samples and variability in hormone levels. CONCLUSION: Deficiency of S-nitrosoglutathione reductase results in secondary hypogonadism, suggesting that excess nitrosative stress can affect LH production from the pituitary gland. Masterson TA, Arora H, Kulandavelu S, et al. S-Nitrosoglutathione Reductase (GSNOR) Deficiency Results in Secondary Hypogonadism. J Sex Med 2018;15:654-661.
Assuntos
Aldeído Oxirredutases/deficiência , Hipogonadismo/etiologia , Hipogonadismo/patologia , 17-Hidroxiesteroide Desidrogenases/metabolismo , Animais , Gonadotropina Coriônica/metabolismo , Hormônio Foliculoestimulante/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Hormônio Luteinizante/metabolismo , Masculino , Camundongos , Estresse Nitrosativo/fisiologia , Contagem de Espermatozoides , Testículo/patologia , Testosterona/metabolismoRESUMO
The gonadotropin-releasing hormone (GnRH) is the master regulator of fertility and kisspeptin (KP) is a potent trigger of GnRH secretion from GnRH neurons. KP signals via KISS1R, a Gαq/11-coupled receptor, and mice bearing a global deletion of Kiss1r (Kiss1r(-/-)) or a GnRH neuron-specific deletion of Kiss1r (Kiss1r(d/d)) display hypogonadotropic hypogonadism and infertility. KISS1R also signals via ß-arrestin, and in mice lacking ß-arrestin-1 or -2, KP-triggered GnRH secretion is significantly diminished. Based on these findings, we hypothesized that ablation of Gαq/11 in GnRH neurons would diminish but not completely block KP-triggered GnRH secretion and that Gαq/11-independent GnRH secretion would be sufficient to maintain fertility. To test this, Gnaq (encodes Gαq) was selectively inactivated in the GnRH neurons of global Gna11 (encodes Gα11)-null mice by crossing Gnrh-Cre and Gnaq(fl/fl);Gna11(-/-) mice. Experimental Gnaq(fl/fl);Gna11(-/-);Gnrh-Cre (Gnaq(d/d)) and control Gnaq(fl/fl);Gna11(-/-) (Gnaq(fl/fl)) littermate mice were generated and subjected to reproductive profiling. This process revealed that testicular development and spermatogenesis, preputial separation, and anogenital distance in males and day of vaginal opening and of first estrus in females were significantly less affected in Gnaq(d/d) mice than in previously characterized Kiss1r(-/-) or Kiss1r(d/d) mice. Additionally, Gnaq(d/d) males were subfertile, and although Gnaq(d/d) females did not ovulate spontaneously, they responded efficiently to a single dose of gonadotropins. Finally, KP stimulation triggered a significant increase in gonadotropins and testosterone levels in Gnaq(d/d) mice. We therefore conclude that the milder reproductive phenotypes and maintained responsiveness to KP and gonadotropins reflect Gαq/11-independent GnRH secretion and activation of the neuroendocrine-reproductive axis in Gnaq(d/d) mice. SIGNIFICANCE STATEMENT: The gonadotropin-releasing hormone (GnRH) is the master regulator of fertility. Over the last decade, several studies have established that the KISS1 receptor, KISS1R, is a potent trigger of GnRH secretion and inactivation of KISS1R on the GnRH neuron results in infertility. While KISS1R is best understood as a Gαq/11-coupled receptor, we previously demonstrated that it could couple to and signal via non-Gαq/11-coupled pathways. The present study confirms these findings and, more importantly, while it establishes Gαq/11-coupled signaling as a major conduit of GnRH secretion, it also uncovers a significant role for non-Gαq/11-coupled signaling in potentiating reproductive development and function. This study further suggests that by augmenting signaling via these pathways, GnRH secretion can be enhanced to treat some forms of infertility.
Assuntos
Subunidades alfa de Proteínas de Ligação ao GTP/deficiência , Hormônio Liberador de Gonadotropina/fisiologia , Hipogonadismo/fisiopatologia , Infertilidade Feminina/fisiopatologia , Infertilidade Masculina/fisiopatologia , Animais , Blastocisto/patologia , Desenvolvimento Embrionário , Feminino , Subunidades alfa de Proteínas de Ligação ao GTP/fisiologia , Perfilação da Expressão Gênica , Genitália Feminina/patologia , Genitália Feminina/fisiopatologia , Genitália Masculina/patologia , Genitália Masculina/fisiopatologia , Hormônios Esteroides Gonadais/metabolismo , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Gonadotropinas Hipofisárias/metabolismo , Gonadotropinas Hipofisárias/farmacologia , Hipogonadismo/genética , Hipogonadismo/patologia , Sistema Hipotálamo-Hipofisário/fisiopatologia , Hipotálamo/patologia , Infertilidade Feminina/embriologia , Infertilidade Feminina/genética , Infertilidade Masculina/embriologia , Infertilidade Masculina/genética , Kisspeptinas/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Oligopeptídeos/farmacologia , Ovariectomia , Ovulação/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Peptídeos/farmacologia , Fenótipo , Receptores Acoplados a Proteínas G , Receptores de Kisspeptina-1 , EspermatogêneseRESUMO
BACKGROUND: The onset of puberty is first detected as an increase in pulsatile secretion of gonadotropin-releasing hormone (GnRH). Early activation of the hypothalamic-pituitary-gonadal axis results in central precocious puberty. The timing of pubertal development is driven in part by genetic factors, but only a few, rare molecular defects associated with central precocious puberty have been identified. METHODS: We performed whole-exome sequencing in 40 members of 15 families with central precocious puberty. Candidate variants were confirmed with Sanger sequencing. We also performed quantitative real-time polymerase-chain-reaction assays to determine levels of messenger RNA (mRNA) in the hypothalami of mice at different ages. RESULTS: We identified four novel heterozygous mutations in MKRN3, the gene encoding makorin RING-finger protein 3, in 5 of the 15 families; both sexes were affected. The mutations included three frameshift mutations, predicted to encode truncated proteins, and one missense mutation, predicted to disrupt protein function. MKRN3 is a paternally expressed, imprinted gene located in the Prader-Willi syndrome critical region (chromosome 15q11-q13). All affected persons inherited the mutations from their fathers, a finding that indicates perfect segregation with the mode of inheritance expected for an imprinted gene. Levels of Mkrn3 mRNA were high in the arcuate nucleus of prepubertal mice, decreased immediately before puberty, and remained low after puberty. CONCLUSIONS: Deficiency of MKRN3 causes central precocious puberty in humans. (Funded by the National Institutes of Health and others.).
Assuntos
Mutação da Fase de Leitura , Mutação de Sentido Incorreto , Puberdade Precoce/genética , Ribonucleoproteínas/genética , Animais , Núcleo Arqueado do Hipotálamo/química , Criança , Pré-Escolar , Exoma , Feminino , Estudos de Associação Genética , Heterozigoto , Humanos , Hipotálamo/metabolismo , Masculino , Camundongos , Linhagem , RNA Mensageiro/análise , Ribonucleoproteínas/deficiência , Análise de Sequência de DNA , Ubiquitina-Proteína LigasesRESUMO
INTRODUCTION: Many missense variants in G protein-coupled receptors (GPCRs) involved in the neuroendocrine regulation of reproduction have been identified by phenotype-driven or large-scale exome sequencing. Computational functional prediction analysis is commonly performed to evaluate their impact on receptor function. METHODS: To assess the performance and outcome of functional prediction analyses for these GPCRs, we performed a statistical analysis of the prediction performance of SIFT and PolyPhen-2 for variants with documented biological function as well as variants retrieved from Ensembl. We obtained missense variants with documented biological function testing from patients with reproductive disorders from a comprehensive literature search. Missense variants from individuals with known reproductive disorders were retrieved from the Human Gene Mutation Database. Missense variants from the general population were retrieved from the Ensembl genome database. RESULTS: The accuracies of SIFT and PolyPhen-2 were 83 and 85%, respectively. The performance of both prediction tools was greater in predicting loss-of-function variants (SIFT: 92%; PolyPhen-2: 95%) than in predicting variants that did not affect function (SIFT: 54%; PolyPhen-2: 57%). Concordance between SIFT and PolyPhen-2 did not improve accuracy. Surprisingly, approximately half of the variants retrieved from Ensembl were predicted as loss-of-function variants by SIFT (47%) and PolyPhen-2 (54%). CONCLUSION: Our findings provide new guidance for interpreting the results and limitations of computational functional prediction analyses for GPCRs and will help to determine which variants require biological function testing. In addition, our findings raise important questions regarding the link between genotype and phenotype in the general population.
Assuntos
Biologia Computacional , Mutação de Sentido Incorreto/genética , Sistemas Neurossecretores/fisiopatologia , Receptores Acoplados a Proteínas G/genética , Reprodução/genética , Feminino , Humanos , Infertilidade Masculina/genética , Masculino , Técnicas de Diagnóstico Molecular , Fenótipo , Polimorfismo de Nucleotídeo Único , Valor Preditivo dos Testes , PubMed/estatística & dados numéricos , Receptores de Kisspeptina-1 , Receptores LHRH/genética , Receptores da Neurocinina-3/genética , Receptores de Peptídeos/genética , SoftwareRESUMO
The adipocyte-derived hormone leptin plays a critical role in the central transmission of energy balance to modulate reproductive function. However, the neurocircuitry underlying this interaction remains elusive, in part due to incomplete knowledge of first-order leptin-responsive neurons. To address this gap, we explored the contribution of predominantly inhibitory (GABAergic) neurons versus excitatory (glutamatergic) neurons in the female mouse by selective ablation of the leptin receptor in each neuronal population: Vgat-Cre;Lepr(lox/lox) and Vglut2-Cre;Lepr(lox/lox) mice, respectively. Female Vgat-Cre;Lepr(lox/lox) but not Vglut2-Cre;Lepr(lox/lox) mice were obese. Vgat-Cre;Lepr(lox/lox) mice had delayed or absent vaginal opening, persistent diestrus, and atrophic reproductive tracts with absent corpora lutea. In contrast, Vglut2-Cre;Lepr(lox/lox) females exhibited reproductive maturation and function comparable to Lepr(lox/lox) control mice. Intracerebroventricular administration of kisspeptin-10 to Vgat-Cre;Lepr(lox/lox) female mice elicited robust gonadotropin responses, suggesting normal gonadotropin-releasing hormone neuronal and gonadotrope function. However, adult ovariectomized Vgat-Cre;Lepr(lox/lox) mice displayed significantly reduced levels of Kiss1 (but not Tac2) mRNA in the arcuate nucleus, and a reduced compensatory luteinizing hormone increase compared with control animals. Estradiol replacement after ovariectomy inhibited gonadotropin release to a similar extent in both groups. These animals also exhibited a compromised positive feedback response to sex steroids, as shown by significantly lower Kiss1 mRNA levels in the AVPV, compared with Lepr(lox/lox) mice. We conclude that leptin-responsive GABAergic neurons, but not glutamatergic neurons, act as metabolic sensors to regulate fertility, at least in part through modulatory effects on kisspeptin neurons.
Assuntos
Fertilidade/fisiologia , Neurônios GABAérgicos/metabolismo , Kisspeptinas/metabolismo , Leptina/metabolismo , Receptores para Leptina/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/efeitos dos fármacos , Núcleo Arqueado do Hipotálamo/metabolismo , Estradiol/farmacologia , Feminino , Fertilidade/efeitos dos fármacos , Neurônios GABAérgicos/efeitos dos fármacos , Kisspeptinas/genética , Kisspeptinas/farmacologia , Hormônio Luteinizante/sangue , Camundongos , Camundongos Knockout , Receptores para Leptina/genética , Transdução de Sinais/efeitos dos fármacosRESUMO
Neurokinin B (NKB) and its G-protein-coupled receptor, NK3R, have been implicated in the neuroendocrine control of GnRH release; however, little is known about the structure-function relationship of this ligand-receptor pair. Moreover, loss-of-function NK3R mutations cause GnRH deficiency in humans. Using missense mutations in NK3R we previously identified in patients with GnRH deficiency, we demonstrate that Y256H and Y315C NK3R mutations in the fifth and sixth transmembrane domains (TM5 and TM6), resulted in reduced whole-cell (79.3±7.2%) or plasma membrane (67.3±7.3%) levels, respectively, compared with wild-type (WT) NK3R, with near complete loss of inositol phosphate (IP) signaling, implicating these domains in receptor trafficking, processing, and/or stability. We further demonstrate in a FRET-based assay that R295S NK3R, in the third intracellular loop (IL3), bound NKB but impaired dissociation of Gq-protein subunits from the receptor compared with WT NK3R, which showed a 10.0 ± 1.3% reduction in FRET ratios following ligand binding, indicating activation of Gq-protein signaling. Interestingly, R295S NK3R, identified in the heterozygous state in a GnRH-deficient patient, also interfered with dissociation of G proteins and IP signaling from wild-type NK3R, indicative of dominant-negative effects. Collectively, our data illustrate roles for TM5 and TM6 in NK3R trafficking and ligand binding and for IL3 in NK3R signaling.
Assuntos
Hormônio Liberador de Gonadotropina/deficiência , Mutação de Sentido Incorreto , Receptores da Neurocinina-3/genética , Transdução de Sinais/genética , Animais , Sítios de Ligação/genética , Ligação Competitiva/genética , Western Blotting , Células COS , Membrana Celular/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Transferência Ressonante de Energia de Fluorescência , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Células HEK293 , Humanos , Fosfatos de Inositol/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microscopia de Fluorescência , Neurocinina B/genética , Neurocinina B/metabolismo , Fosforilação , Multimerização Proteica , Receptores da Neurocinina-3/química , Receptores da Neurocinina-3/metabolismoRESUMO
Glioblastoma contains a hierarchy of stem-like cancer cells, but how this hierarchy is established is unclear. Here, we show that asymmetric Numb localization specifies glioblastoma stem-like cell (GSC) fate in a manner that does not require Notch inhibition. Numb is asymmetrically localized to CD133-hi GSCs. The predominant Numb isoform, Numb4, decreases Notch and promotes a CD133-hi, radial glial-like phenotype. However, upregulation of a novel Numb isoform, Numb4 delta 7 (Numb4d7), increases Notch and AKT activation while nevertheless maintaining CD133-hi fate specification. Numb knockdown increases Notch and promotes growth while favoring a CD133-lo, glial progenitor-like phenotype. We report the novel finding that Numb4 (but not Numb4d7) promotes SCF(Fbw7) ubiquitin ligase assembly and activation to increase Notch degradation. However, both Numb isoforms decrease epidermal growth factor receptor (EGFR) expression, thereby regulating GSC fate. Small molecule inhibition of EGFR activity phenocopies the effect of Numb on CD133 and Pax6. Clinically, homozygous NUMB deletions and low Numb mRNA expression occur primarily in a subgroup of proneural glioblastomas. Higher Numb expression is found in classical and mesenchymal glioblastomas and correlates with decreased survival. Thus, decreased Numb promotes glioblastoma growth, but the remaining Numb establishes a phenotypically diverse stem-like cell hierarchy that increases tumor aggressiveness and therapeutic resistance.
Assuntos
Receptores ErbB/metabolismo , Glioma/metabolismo , Proteínas de Membrana/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Ligases SKP Culina F-Box/metabolismo , Antígeno AC133 , Animais , Antígenos CD/genética , Antígenos CD/metabolismo , Western Blotting , Linhagem Celular , Receptores ErbB/genética , Citometria de Fluxo , Glioma/genética , Glicoproteínas/genética , Glicoproteínas/metabolismo , Humanos , Imuno-Histoquímica , Imunoprecipitação , Técnicas In Vitro , Proteínas de Membrana/genética , Camundongos , Camundongos Nus , Proteínas do Tecido Nervoso/genética , Peptídeos/genética , Peptídeos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Ligases SKP Culina F-Box/genética , Células Tumorais CultivadasRESUMO
Introduction Education on health care for patients with diverse sexual orientation, sex characteristics and gender identities is lacking in Aotearoa's medical schools. Aim This study surveyed fifth-year medical students at the University of Otago Wellington (UOW) about confidence in providing health care to lesbian, gay, bisexual, transgender, queer, intersex and asexual (LGBTQIA+) patients to identify learning needs. Methods This anonymous cross-sectional survey was designed with input from an advisory group (community members, education, research and subject matter experts). It was administered on paper during class, using Likert scales (level of agreement) and open-ended questions. All fifth-year medical students at the UOW campus were invited to participate in May 2021. Data were analysed in Microsoft Excel (Microsoft Corporation) and free-text comments were analysed using template analysis. Results In total, 74.7% (71/95) of students completed a survey. Participants lacked knowledge and confidence in their consultation skills with LGBTQIA+ patients and did not feel they had enough teaching in this area. Most (≥78.8%) were comfortable with common terms, but half or fewer could explain intersex, gender affirmation and Takatapui. Free-text comments revealed learning needs relating to consultation skills, ways to approach this topic with sensitivity, and a desire to learn more about the cultural context. Discussion Medical students view LGBTQIA+ health care as an important topic and want opportunities to improve knowledge and confidence in this area. Students lack confidence in consulting with LGBTQIA+ patients, suggesting that more education focused on practical experience and interactions with real patients would be of benefit.
Assuntos
Minorias Sexuais e de Gênero , Estudantes de Medicina , Pessoas Transgênero , Masculino , Humanos , Feminino , Estudos Transversais , Comportamento SexualRESUMO
Introduction Traditionally, gender-affirming hormonal therapy (GAHT) is initiated in secondary care, but a primary care based approach has been developed to reduce access barriers. Aim We aim to describe the demographics, hormone choices, and additional referrals made for young people initiating GAHT in a primary care setting in Aotearoa New Zealand. Methods Clinical notes were reviewed for all patients who commenced GAHT between 1 July 2020 to the end of 2022 at a tertiary education health service. Data were collected on age, ethnicity, gender, type of hormones prescribed, and any additional referrals. Results Eighty five patients commenced GAHT during the review period (64% assigned male at birth and starting oestrogen-based GAHT, 36% assigned female at birth and commencing testosterone-based GAHT). Fourty seven percent of patients identified as transgender female, 38% as non-binary, and 15% as transgender male. Spironolactone was the most common choice of testosterone blocker (81%). The choice of oestrogen formulation was fairly equal between patches (54%) and tablets (46%). Eighty percent of those assigned male at birth chose to preserve fertility, 54% requested voice therapy, and 87% of those assigned female at birth requested top surgery. Discussion There is a need for improved understanding of non-binary gender-affirmation needs, in particular those of Maori and Pasifika youth. An informed consent approach in primary care can reduce barriers and distress for transgender youth seeking GAHT. The high unmet need for top surgery for transgender people assigned female at birth requires attention.
Assuntos
Serviços de Saúde para Pessoas Transgênero , Serviços de Saúde para Estudantes , Pessoas Transgênero , Adolescente , Feminino , Humanos , Masculino , Atenção à Saúde , Povo Maori , Nova Zelândia , EstudantesRESUMO
Studies in humans and mice support a role for Makorin RING finger protein 3 (MKRN3) as an inhibitor of gonadotropin-releasing hormone (GnRH) secretion prepubertally, and its loss of function is the most common genetic cause of central precocious puberty in humans. Studies have shown that the gonads can synthesize neuropeptides and express MKRN3/Mkrn3 mRNA. Therefore, we aimed to investigate the spatiotemporal expression pattern of Mkrn3 in gonads during sexual development, and its potential regulation in the functional testicular compartments by gonadotropins. Mkrn3 mRNA was detected in testes and ovaries of wild-type mice at all ages evaluated, with a sexually dimorphic expression pattern between male and female gonads. Mkrn3 expression was highest peripubertally in the testes, whereas it was lower peripubertally than prepubertally in the ovaries. Mkrn3 is expressed primarily in the interstitial compartment of the testes but was also detected at low levels in the seminiferous tubules. In vitro studies demonstrated that Mkrn3 mRNA levels increased in human chorionic gonadotropin (hCG)-treated Leydig cell primary cultures. Acute administration of a GnRH agonist in adult mice increased Mkrn3 expression in testes, whereas inhibition of the hypothalamic-pituitary-gonadal axis by chronic administration of GnRH agonist had the opposite effect. Finally, we found that hCG increased Mkrn3 mRNA levels in a dose-dependent manner. Taken together, our developmental expression analyses, in vitro and in vivo studies show that Mkrn3 is expressed in the testes, predominantly in the interstitial compartment, and that Mkrn3 expression increases after puberty and is responsive to luteinizing hormone/hCG stimulation.