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1.
Cureus ; 16(3): e55757, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38586643

RESUMO

Galantamine is commonly used to manage symptoms of Alzheimer's disease and other cognitive disorders. While it is generally well-tolerated, cardiovascular side effects are rare but can be serious. We report the case of a patient who developed a third-degree heart block after initiating galantamine therapy. This case highlights the importance of monitoring patients for cardiac adverse effects when using galantamine and the need for prompt intervention when such effects occur.

2.
Ann Hematol ; 103(4): 1131-1137, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37428199

RESUMO

PNS are uncommon manifestations of cancer. The current literature about these syndromes in the setting of cHL is disintegrated. A systematic literature review of all published literature was conducted. One hundred twenty-eight patients from 115 publications met the inclusion/exclusion criteria. Eight-five patients were of the NS subtype (66.4%). The most frequent clinical presentation of the PNS was CNS manifestation (25.8%). The majority of patients were diagnosed with the cHL and PNS simultaneously (42.2%). In 33.6% of patients, the lymphoma diagnosis preceded the PNS diagnosis. In 16.4% of patients, the PNS diagnosis preceded the lymphoma diagnosis. The presence of PNS antibodies was reported in 35 patients (27.3%). Age older than 18 was associated with higher prevalence of PNS. The CR rate of the lymphoma was 77.3%. The complete resolution rate of the PNS was 54.7%. Relapse of lymphoma was reported in 13 patients, and recurrence of the PNS upon relapse was reported in 10/13 patients.


Assuntos
Doença de Hodgkin , Síndromes Paraneoplásicas do Sistema Nervoso , Síndromes Paraneoplásicas , Humanos , Síndromes Paraneoplásicas do Sistema Nervoso/diagnóstico , Doença de Hodgkin/complicações , Recidiva Local de Neoplasia , Síndromes Paraneoplásicas/epidemiologia , Síndromes Paraneoplásicas/etiologia , Recidiva
3.
Front Immunol ; 13: 1005031, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36263054

RESUMO

Background: Natural killer (NK) cells play a vital role in early immune reconstitution following allogeneic hematopoietic stem cell transplantation (HSCT). Methods: A literature search was performed on PubMed, Cochrane, and Clinical trials.gov through April 20, 2022. We included 21 studies reporting data on the impact of NK cells on outcomes after HSCT. Data was extracted following the PRISMA guidelines. Pooled analysis was done using the meta-package (Schwarzer et al.). Proportions with 95% confidence intervals (CI) were computed. Results: We included 1785 patients from 21 studies investigating the impact of NK cell reconstitution post-HSCT (8 studies/1455 patients), stem cell graft NK cell content (4 studies/185 patients), therapeutic NK cell infusions post-HSCT (5 studies/74 patients), and pre-emptive/prophylactic NK cell infusions post-HSCT (4 studies/77 patients). Higher NK cell reconstitution was associated with a better 2-year overall survival (OS) (high: 77%, 95%CI 0.73-0.82 vs low: 55%, 95%CI 0.37-0.72; n=899), however, pooled analysis for relapse rate (RR) or graft versus host disease (GVHD) could not be performed due to insufficient data. Higher graft NK cell content demonstrated a trend towards a better pooled OS (high: 65.2%, 95%CI 0.47-0.81 vs low: 46.5%, 95%CI 0.24-0.70; n=157), lower RR (high: 16.9%, 95%CI 0.10-0.25 vs low: 33%, 95%CI 0.04-0.72; n=157), and lower acute GVHD incidence (high: 27.6%, 95%CI 0.20-0.36 vs low: 49.7%, 95%CI 0.26-0.74; n=157). Therapeutic NK or cytokine-induced killer (CIK) cell infusions for hematologic relapse post-HSCT reported an overall response rate (ORR) and complete response (CR) of 48.9% and 11% with CIK cell infusions and 82.8% and 44.8% with NK cell infusions, respectively. RR, acute GVHD, and chronic GVHD were observed in 55.6% and 51.7%, 34.5% and 20%, and 20.7% and 11.1% of patients with CIK and NK cell infusions, respectively. Pre-emptive donor-derived NK cell infusions to prevent relapse post-HSCT had promising outcomes with 1-year OS of 69%, CR rate of 42%, ORR of 77%, RR of 28%, and acute and chronic GVHD rates of 24.9% and 3.7%, respectively. Conclusion: NK cells have a favorable impact on outcomes after HSCT. The optimal use of NK cell infusions post-HSCT may be in a pre-emptive fashion to prevent disease relapse.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Humanos , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Células Matadoras Naturais , Recidiva , Citocinas
4.
Curr Drug Metab ; 22(9): 698-708, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34325630

RESUMO

BACKGROUND: In recent years, the significance of cytochrome P450 enzymes (CYPs) has expanded beyond their role in the liver. Factors such as genetics, environmental toxins, drug biotransformation and underlying diseases mediate the expression of these enzymes. Among the CYP enzymes, CYP2E1, a well-recognized monooxygenase enzyme involved in the metabolism of various endogenous and exogenous substances, plays a crucial role in the brain concerning the development of Parkinson's disease. The expression of CYP2E1 varies in different brain regions making certain regions more vulnerable than others. CYP2E1 expression is inducible which generates tissuedamaging radicals leading to oxidative stress, mitochondrial dysfunction and ultimately neurodegeneration. OBJECTIVE: Less is understood about the role of CYP2E1 in the central nervous system, therefore the purpose of the study was to investigate the relationship between the expression and activity of CYP2E1 enzyme relevant to Parkinson's disease and to identify whether an increase in the expression of CYP2E1 is associated with neurodegeneration. METHODS: The objectives of the study were achieved by implicating an unsystematic integrative literature review approach in which the literature was qualitatively analysed, critically evaluated and a new theory with an overall view of the mechanism was presented. RESULTS: The contribution of CYP2E1 in the development of Parkinson's disease was found to be significant as the negative effects of CYP2E1 overshadowed its protective detoxifying role. CONCLUSION: Overexpression of CYP2E1 seems detrimental to dopaminergic neurons, therefore, to overcome this, a synthetic biochemical is required, which paves the way for further research and development of valuable biomolecules.


Assuntos
Encéfalo/metabolismo , Citocromo P-450 CYP2E1/metabolismo , Doença de Parkinson , Neurônios Dopaminérgicos/metabolismo , Descoberta de Drogas , Regulação da Expressão Gênica , Humanos , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/etiologia , Doença de Parkinson/metabolismo
5.
J Pak Med Assoc ; 71(5): 1479-1482, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34091639

RESUMO

A descriptive, cross-sectional study was conducted from July 2018 to September 2018 to assess the level of awareness among healthcare workers regarding rotavirus infection and its vaccination in Rawalpindi and Islamabad. The study site was conducted at tertiary care hospitals of Rawalpindi and Islamabad. Ethical approval was obtained from the Institutional Review Board of Army Medical College, Rawalpindi. Closed and open ended questionnaires were distributed via non-probability convenient sampling. The sample size was 257. Among the study participants, 247 (96.1%) of the participants had good level of awareness regarding rotavirus, whereas 212 (82.5%) had awareness regarding the vaccine. The mean awareness score was 16.16 ± 4.097 out of a maximum score of 22. Both male and female participants had almost equal awareness regarding the rotavirus infection (Males = 96, 93.2%, Females = 151, 98%) and vaccination (Males = 87, 84%, Females = 125, 81.1%). The mean awareness was directly related with the level of education of the participants, i.e. MBBS/FCPS/MCPS = 221(85.9%), MBBS = 209(81.5%), B.Sc. Nursing = 206(80%), and Basic Education = 220(85.7%) knew about the vaccine.


Assuntos
Infecções por Rotavirus , Rotavirus , Vacinas , Estudos Transversais , Feminino , Pessoal de Saúde , Humanos , Masculino , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/prevenção & controle , Atenção Terciária à Saúde
6.
Curr Opin Nephrol Hypertens ; 30(5): 507-515, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34148978

RESUMO

PURPOSE OF REVIEW: To provide an overview of the skill set required for communication and person-centered decision making for renal replacement therapy (RRT) choices, especially conservative kidney management (CKM). RECENT FINDINGS: Research on communication and decision-making skills for shared RRT decision making is still in infancy. We adapt literature from other fields such as primary care and oncology for effective RRT decision making. SUMMARY: We review seven key skills: (1) Announcing the need for decision making (2) Agenda Setting (3) Educating patients about RRT options (4) Discussing prognoses (5) Eliciting patient preferences (6) Responding to emotions and showing empathy, and (7) Investing in the end. We also provide example sentences to frame the conversations around RRT choices including CKM.


Assuntos
Comunicação , Terapia de Substituição Renal , Tratamento Conservador , Tomada de Decisões , Humanos , Preferência do Paciente , Prognóstico
7.
PLoS Genet ; 16(4): e1008721, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32339198

RESUMO

Current estimates suggest 50% of glaucoma blindness worldwide is caused by primary angle-closure glaucoma (PACG) but the causative gene is not known. We used genetic linkage and whole genome sequencing to identify Spermatogenesis Associated Protein 13, SPATA13 (NM_001166271; NP_001159743, SPATA13 isoform I), also known as ASEF2 (Adenomatous polyposis coli-stimulated guanine nucleotide exchange factor 2), as the causal gene for PACG in a large seven-generation white British family showing variable expression and incomplete penetrance. The 9 bp deletion, c.1432_1440del; p.478_480del was present in all affected individuals with angle-closure disease. We show ubiquitous expression of this transcript in cell lines derived from human tissues and in iris, retina, retinal pigment and ciliary epithelia, cornea and lens. We also identified eight additional mutations in SPATA13 in a cohort of 189 unrelated PACS/PAC/PACG samples. This gene encodes a 1277 residue protein which localises to the nucleus with partial co-localisation with nuclear speckles. In cells undergoing mitosis SPATA13 isoform I becomes part of the kinetochore complex co-localising with two kinetochore markers, polo like kinase 1 (PLK-1) and centrosome-associated protein E (CENP-E). The 9 bp deletion reported in this study increases the RAC1-dependent guanine nucleotide exchange factors (GEF) activity. The increase in GEF activity was also observed in three other variants identified in this study. Taken together, our data suggest that SPATA13 is involved in the regulation of mitosis and the mutations dysregulate GEF activity affecting homeostasis in tissues where it is highly expressed, influencing PACG pathogenesis.


Assuntos
Glaucoma de Ângulo Aberto/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Mutação , Adolescente , Adulto , Idoso , Divisão Celular , Núcleo Celular/metabolismo , Olho/metabolismo , Feminino , Glaucoma de Ângulo Aberto/patologia , Fatores de Troca do Nucleotídeo Guanina/química , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Cinetocoros/metabolismo , Masculino , Pessoa de Meia-Idade , Linhagem , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Transporte Proteico
8.
Hum Mol Genet ; 28(23): 3867-3879, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31807779

RESUMO

The neuronal ceroid lipofuscinoses (NCLs), more commonly referred to as Batten disease, are a group of inherited lysosomal storage disorders that present with neurodegeneration, loss of vision and premature death. There are at least 13 genetically distinct forms of NCL. Enzyme replacement therapies and pre-clinical studies on gene supplementation have shown promising results for NCLs caused by lysosomal enzyme deficiencies. The development of gene therapies targeting the brain for NCLs caused by defects in transmembrane proteins has been more challenging and only limited therapeutic effects in animal models have been achieved so far. Here, we describe the development of an adeno-associated virus (AAV)-mediated gene therapy to treat the neurodegeneration in a mouse model of CLN6 disease, a form of NCL with a deficiency in the membrane-bound protein CLN6. We show that neonatal bilateral intracerebroventricular injections with AAV9 carrying CLN6 increase lifespan by more than 90%, maintain motor skills and motor coordination and reduce neuropathological hallmarks of Cln6-deficient mice up to 23 months post vector administration. These data demonstrate that brain-directed gene therapy is a valid strategy to treat the neurodegeneration of CLN6 disease and may be applied to other forms of NCL caused by transmembrane protein deficiencies in the future.


Assuntos
Vetores Genéticos/administração & dosagem , Proteínas de Membrana/genética , Lipofuscinoses Ceroides Neuronais/terapia , Animais , Animais Recém-Nascidos , Encéfalo/crescimento & desenvolvimento , Dependovirus/genética , Modelos Animais de Doenças , Terapia Genética , Humanos , Injeções Intraventriculares , Proteínas de Membrana/metabolismo , Camundongos , Lipofuscinoses Ceroides Neuronais/genética , Lipofuscinoses Ceroides Neuronais/metabolismo , Resultado do Tratamento
10.
J Pharm Bioallied Sci ; 9(3): 216-220, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28979077

RESUMO

INTRODUCTION: The ailments afflicting the elderly population is a well-defined specialty of medicine. It calls for an immaculately designed health-care plan to treat diseases in geriatrics. For chronic illnesses such as diabetes mellitus (DM), coronary heart disease, and hypertension (HTN), they require proper management throughout the rest of patient's life. An integrated treatment pathway helps in treatment decision-making and improving standards of health care for the patient. CASE PRESENTATION: This case describes an exclusive clinical pharmacist-driven designing of an integrated treatment pathway for a post-coronary artery bypass grafting (CABG) geriatric male patient with DM type I and HTN for the treatment of hypoglycemia and electrolyte imbalance. INTERVENTION: The treatment begins addressing the chief complaints which were vomiting and unconsciousness. Biochemical screening is essential to establish a diagnosis of electrolyte imbalance along with blood glucose level after which the integrated pathway defines the treatment course. CONCLUSION: This individualized treatment pathway provides an outline of the course of treatment of acute hypoglycemia, electrolyte imbalance as well as some unconfirmed diagnosis, namely, acute coronary syndrome and respiratory tract infection for a post-CABG geriatric patient with HTN and type 1 DM. The eligibility criterion for patients to be treated according to treatment pathway is to fall in the defined category.

11.
An Acad Bras Cienc ; 88(4): 2303-2317, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27925034

RESUMO

The aim of present study was to enhance topical permeation of clotrimazole gel preparation by using various permeability enhancers such as coconut oil, pistachio oil and sodium lauryl sulphate (SLS). Clotrimazole gel preparations were prepared and optimized by using three factor, five level central composite design. A second-order polynomial equation was generated in order to estimate the effect of independent variables i.e. coconut oil (X1), pistachio oil (X2) and sodium lauryl sulphate (X3) at various dependent variables i.e. flux (Y1), lag time (Y2), diffusion coefficient (Y3), permeability coefficient (Y4), and input rate (Y5) of clotrimazole gel formulations. Ex vivo skin permeation study was performed through rat skin by using modified Franz diffusion cell system. Optimized formulation F8 exhibited highest flux 2.17 µg/cm2/min, permeability coefficient 0.0019 cm/min and input rate 1.543 µg/cm2/min, along with moderate lag time 77.27 min and diffusion coefficient 0.063 cm2/min, which is further supported by anti-fungal activity that exhibited more prominent zone of inhibition against Candida albicans, Aspergillus niger and Mucor. Thus, it can be concluded that permeation of clotrimazole gel was enhanced by various combination of coconut oil, pistachio oil and sodium lauryl sulphate but optimized formulation F8 containing 0.4 ml pistachio oil, 0.8 ml coconut oil and 0.04 g of SLS exhibited more pronounced and promising effect through rat skin.


Assuntos
Acrilatos , Clotrimazol/síntese química , Administração Tópica , Animais , Clotrimazol/administração & dosagem , Clotrimazol/farmacocinética , Óleo de Coco/farmacologia , Composição de Medicamentos/métodos , Géis , Técnicas In Vitro , Pistacia/química , Óleos de Plantas/farmacologia , Ratos , Absorção Cutânea , Dodecilsulfato de Sódio/farmacologia
12.
PLoS One ; 11(11): e0166397, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27846257

RESUMO

PURPOSE: Mutations in the EYS gene are a common cause of autosomal recessive retinitis pigmentosa (arRP), yet the role of the EYS protein in humans is presently unclear. The aim of this study was to investigate the isoform structure, expression and potential function of EYS in the mammalian retina in order to better understand its involvement in the pathogenesis of arRP. METHODS: To achieve the objective, we examined the expression of mRNA transcripts of EYS isoforms in human tissues and cell lines by RT-PCR. We also investigated the localisation of EYS in cultured cells and retinal cryo-sections by confocal fluorescence microscopy and Western blot analysis. RESULTS: RT-PCR analysis confirmed that EYS has at least four isoforms. In addition to the previously reported EYS isoforms 1 and 4, we present the experimental validation of two smaller variants referred to as EYS isoforms 2 and 3. All four isoforms are expressed in the human retina and Y79 cells and the short variants were additionally detected in the testis. Immunofluorescent confocal microscopy and Western blot analysis revealed that all EYS isoforms preferentially localise to the cytoplasm of Y79 and HeLa cells. Moreover, an enrichment of the endogenous protein was observed near the centrosomes in Y79 cells. Interestingly, EYS was observed at the ciliary axoneme in Y79 ciliated cells. In macaque retinal cryosections, EYS was found to localise in the region of the photoreceptor ciliary axoneme in both rods and cones as well as in the cytoplasm of the ganglion cells. CONCLUSION: The results obtained in this study lead us to speculate that, in photoreceptor cells, EYS could be a protein involved in maintaining the stability of the ciliary axoneme in both rods and cones. The variability of its isoform structure suggests that other roles are also possible and yet to be established.


Assuntos
Proteínas do Olho/genética , Células Fotorreceptoras Retinianas Cones/metabolismo , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Retinose Pigmentar/genética , Animais , Axonema/genética , Axonema/metabolismo , Axonema/patologia , Cílios/genética , Cílios/metabolismo , Cílios/patologia , Citoplasma/genética , Citoplasma/metabolismo , Análise Mutacional de DNA , Eletrorretinografia , Proteínas do Olho/metabolismo , Células HeLa , Humanos , Indóis , Macaca/genética , Macaca/metabolismo , Mutação , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Retina/metabolismo , Retina/patologia , Células Fotorreceptoras Retinianas Cones/patologia , Células Fotorreceptoras Retinianas Bastonetes/patologia , Retinose Pigmentar/metabolismo , Retinose Pigmentar/patologia
13.
Ugeskr Laeger ; 178(27)2016 Jul 04.
Artigo em Dinamarquês | MEDLINE | ID: mdl-27406054

RESUMO

Jinn possession is used as an explanation of mental symptoms among Muslims around the world. Very few studies have examined the use of jinn as a religious explanation model for mental health problems and treatment-seeking behaviour. The majority of studies show a positive association between jinn explanations and preferred treatment by religious healers, but due to methodological limitations, results should be taken with precaution. There is a need for longitudinal studies focusing on improving cultural competence and exploring possible cooperation with healers.


Assuntos
Islamismo , Transtornos Mentais/psicologia , Possessão Espiritual , Competência Cultural , Feminino , Humanos , Comunicação Interdisciplinar , Religião e Psicologia , Fatores Socioeconômicos , Terapias Espirituais
14.
Exp Eye Res ; 148: 24-29, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27179412

RESUMO

VAX2 is a transcription factor specifically expressed in the ventral region of the prospective neural retina in vertebrates and is required for ventral eye specification. Despite its extensive analysis in vertebrates, the biological role of VAX2 in the human is presently unclear. This study was undertaken to investigate VAX2 in humans aiming to gain new knowledge into its involvement in retinal function. Here, we report VAX2 gene expression and protein localization in cultured cells and adult retina. RT-PCR experiments indicated that VAX2 is enriched in neuronal tissues. Moreover, we identified a novel isoform most abundantly expressed in the retina. We termed the known transcript (NM_012476) isoform-1, and the newly identified transcript as isoform-2. Analysis of protein localization in cultured cells revealed that isoform-1 localizes to the nucleus and isoform-2 is widely expressed within the cell; partial co-localization of isoform-2 and actin filaments was also observed. In nonhuman primate retina VAX2 was seen either in the nuclear or in the cytoplasmic compartment depending on the retinal cell type. In addition, a noteworthy enrichment of the signal was observed in the outer segment of cone photoreceptors. Overall, this study provides the first insights into the expression of VAX2 in humans and its localization in the adult primate retina. Moreover, preliminary characterization of alternative variants suggests an involvement of VAX2 in multiple cellular pathways. Our findings raise the interesting possibility for further investigation of VAX2 in the retina in health and disease.


Assuntos
Proteínas de Homeodomínio/metabolismo , Retina/metabolismo , Fatores de Transcrição/metabolismo , Animais , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Citoesqueleto/metabolismo , Humanos , Macaca fascicularis , Camundongos , Estudos Prospectivos , Isoformas de Proteínas/metabolismo , Células Fotorreceptoras Retinianas Cones/metabolismo
15.
PLoS One ; 11(2): e0148678, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26872363

RESUMO

The significance of the ubiquitin-proteasome system (UPS) for protein degradation has been highlighted in the context of neurodegenerative diseases, including retinal dystrophies. TOPORS, a dual E3 ubiquitin and SUMO1 ligase, forms a component of the UPS and selected substrates for its enzymatic activities, such as DJ-1/PARK7 and APOBEC2, are important for neuronal as well as retinal homeostasis, respectively. TOPORS is ubiquitously expressed, yet its mutations are only known to result in autosomal dominant retinitis pigmentosa. We performed a yeast two-hybrid (Y2H) screen of a human retinal cDNA library in order to identify interacting protein partners of TOPORS from the retina, and thus begin delineating the putative disease mechanism(s) associated with the retina-specific phenotype resulting from mutations in TOPORS. The screen led to isolation of the 26 S protease regulatory subunit 4 (P26s4/ PSMC1), an ATPase indispensable for correct functioning of UPS-mediated proteostasis. The interaction between endogenous TOPORS and P26s4 proteins was validated by co-immuno-precipitation from mammalian cell extracts and further characterised by immunofluorescent co-localisation studies in cell lines and retinal sections. Findings from hTERT-RPE1 and 661W cells demonstrated that TOPORS and P26s4 co-localise at the centrosome in cultured cells. Immunofluorescent staining of mouse retinae revealed a strong P26s4 reactivity at the interface between retinal pigmented epithelium (RPE) layer and the photoreceptors outer segments (OS). This finding leads us to speculate that P26s4, along with TOPORS, may have a role(s) in RPE phagocytosis, in addition to contributing to the overall photoreceptor and retinal homeostasis via the UPS.


Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Mapas de Interação de Proteínas , Retina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , ATPases Associadas a Diversas Atividades Celulares , Adenosina Trifosfatases/análise , Adenosina Trifosfatases/genética , Animais , Linhagem Celular , DNA Complementar/genética , Humanos , Camundongos , Mutação , Proteínas de Neoplasias/análise , Proteínas de Neoplasias/genética , Proteínas Nucleares/análise , Proteínas Nucleares/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Retina/citologia , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/análise , Ubiquitina-Proteína Ligases/genética
16.
Sci Rep ; 6: 19450, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26781568

RESUMO

PRPF31-associated retinitis pigmentosa presents a fascinating enigma: some mutation carriers are blind, while others are asymptomatic. We identify the major molecular cause of this incomplete penetrance through three cardinal features: (1) there is population variation in the number (3 or 4) of a minisatellite repeat element (MSR1) adjacent to the PRPF31 core promoter; (2) in vitro, 3-copies of the MSR1 element can repress gene transcription by 50 to 115-fold; (3) the higher-expressing 4-copy allele is not observed among symptomatic PRPF31 mutation carriers and correlates with the rate of asymptomatic carriers in different populations. Thus, a linked transcriptional modifier decreases PRPF31 gene expression that leads to haploinsufficiency. This result, taken with other identified risk alleles, allows precise genetic counseling for the first time. We also demonstrate that across the human genome, the presence of MSR1 repeats in the promoters or first introns of genes is associated with greater population variability in gene expression indicating that copy number variation of MSR1s is a generic controller of gene expression and promises to provide new insights into our understanding of gene expression regulation.


Assuntos
Proteínas do Olho/metabolismo , Regulação da Expressão Gênica , Penetrância , Sequências Repetitivas de Ácido Nucleico , Retinose Pigmentar/genética , Retinose Pigmentar/metabolismo , Receptores Depuradores Classe A/genética , Alelos , Sítios de Ligação , Sequência Conservada , Variações do Número de Cópias de DNA , Expressão Gênica , Frequência do Gene , Genes Reporter , Genética Populacional , Genótipo , Humanos , Motivos de Nucleotídeos , Fenótipo , Matrizes de Pontuação de Posição Específica , Regiões Promotoras Genéticas , Transcrição Gênica
18.
Ann Hum Genet ; 78(1): 62-71, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24116917

RESUMO

Mutations in PRPF31 are responsible for autosomal dominant retinitis pigmentosa (adRP, RP11 form) and affected families show nonpenetrance. Differential expression of the wildtype PRPF31 allele is responsible for this phenomenon: coinheritance of a mutation and a higher expressing wildtype allele provide protection against development of disease. It has been suggested that a major modulating factor lies in close proximity to the wildtype PRPF31 gene on Chromosome 19, implying that a cis-acting factor directly alters PRPF31 expression. Variable expression of CNOT3 is one determinant of PRPF31 expression. This study explored the relationship between CNOT3 (a trans-acting factor) and its paradoxical cis-acting nature in relation to RP11. Linkage analysis on Chromosome 19 was performed in mutation-carrying families, and the inheritance of the wildtype PRPF31 allele in symptomatic-asymptomatic sibships was assessed-confirming that differential inheritance of wildtype chromosome 19q13 determines the clinical phenotype (P < 2.6 × 10(-7) ). A theoretical model was constructed that explains the apparent conflict between the linkage data and the recent demonstration that a trans-acting factor (CNOT3) is a major nonpenetrance factor: we propose that this apparently cis-acting effect arises due to the intimate linkage of CNOT3 and PRPF31 on Chromosome 19q13-a novel mechanism that we have termed "linked trans-acting epistasis."


Assuntos
Epistasia Genética , Proteínas do Olho/genética , Genes Recessivos , Polimorfismo Genético , Retinose Pigmentar/genética , Fatores de Transcrição/genética , Alelos , Cromossomos Humanos Par 19/genética , Biologia Computacional , Proteínas do Olho/metabolismo , Feminino , Genes Dominantes , Ligação Genética , Loci Gênicos , Heterozigoto , Humanos , Masculino , Repetições de Microssatélites , Mutação , Linhagem , Pneumonia Aspirativa/genética , Fatores de Transcrição/metabolismo
19.
J Mol Genet Med ; 7(2)2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25729402

RESUMO

Mutations in PRPF31 have been implicated in retinitis pigmentosa, a blinding disease caused by degeneration of rod photoreceptors. The disease mechanism in the majority of cases is haploinsufficiency. Crucially, attempts at generation of animal models of disease have proved unsuccessful, yielding animals with a visual phenotype that does not mirror human disease. This suggests that, in these animals, the transcriptional regulation of PRPF31 is different to humans and compared to other species. Study of the evolution of the PRPF31 core promoter has important implications for our understanding of human disease, as disease phenotype is modified by differentially expressed alleles in the population. PRPF31 lies in a head-to-head arrangement with TFPT, a gene involved in cellular apoptosis. The two genes were shown to share common regulatory elements in the human genome. In this study, the core promoters of PRPF31 and TFPT were characterised by dual-luciferase reporter assay using genomic DNA from the green monkey, domestic dog and house mouse. It was found that the core promoters were conserved between human and monkey. In dog, the TFPT core promoter was conserved, but different PRPF31 gene architecture meant the gene was controlled by a long-range promoter lying some 2000bp from the transcription start site. There was very low level of conservation (<20%) of the PRPF31 5' region between mouse and human. It was shown that mouse populations did not show variable Prpf31 expression levels, revealing a potential explanation for the lack of phenotype observed in the Prpf31 knock-out mouse model.

20.
PLoS Genet ; 8(11): e1003040, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23144630

RESUMO

Heterozygous mutations in the PRPF31 gene cause autosomal dominant retinitis pigmentosa (adRP), a hereditary disorder leading to progressive blindness. In some cases, such mutations display incomplete penetrance, implying that certain carriers develop retinal degeneration while others have no symptoms at all. Asymptomatic carriers are protected from the disease by a higher than average expression of the PRPF31 allele that is not mutated, mainly through the action of an unknown modifier gene mapping to chromosome 19q13.4. We investigated a large family with adRP segregating an 11-bp deletion in PRPF31. The analysis of cell lines derived from asymptomatic and affected individuals revealed that the expression of only one gene among a number of candidates within the 19q13.4 interval significantly correlated with that of PRPF31, both at the mRNA and protein levels, and according to an inverse relationship. This gene was CNOT3, encoding a subunit of the Ccr4-not transcription complex. In cultured cells, siRNA-mediated silencing of CNOT3 provoked an increase in PRPF31 expression, confirming a repressive nature of CNOT3 on PRPF31. Furthermore, chromatin immunoprecipitation revealed that CNOT3 directly binds to a specific PRPF31 promoter sequence, while next-generation sequencing of the CNOT3 genomic region indicated that its variable expression is associated with a common intronic SNP. In conclusion, we identify CNOT3 as the main modifier gene determining penetrance of PRPF31 mutations, via a mechanism of transcriptional repression. In asymptomatic carriers CNOT3 is expressed at low levels, allowing higher amounts of wild-type PRPF31 transcripts to be produced and preventing manifestation of retinal degeneration.


Assuntos
Proteínas do Olho/genética , Penetrância , Retinose Pigmentar , Fatores de Transcrição/genética , Proteínas do Olho/metabolismo , Regulação da Expressão Gênica , Heterozigoto , Humanos , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , RNA Interferente Pequeno , Retinose Pigmentar/genética , Retinose Pigmentar/metabolismo , Deleção de Sequência , Fatores de Transcrição/metabolismo
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