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Introduction: Macular Telangiectasia type 2 (MacTel), is an uncommon form of late-onset, slowly-progressive macular degeneration. Associated with regional Müller glial cell loss in the retina and the amino acid serine synthesized by Müller cells, the disease is functionally confined to a central retinal region - the MacTel zone. Methods: We have used high-throughput multi-resolution electron microscopy techniques, optimized for disease analysis, to study the retinas from two women, mother and daughter, aged 79 and 48 years respectively, suffering from MacTel. Results: In both eyes, the principal observations made were changes specific to mitochondrial structure both outside and within the MacTel zone in all retinal cell types, with the exception of those in the retinal pigment epithelium (RPE). The lesion areas, which are a hallmark of MacTel, extend from Bruch's membrane and the choriocapillaris, through all depths of the retina, and include cells from the RPE, retinal vascular elements, and extensive hypertrophic basement membrane material. Where the Müller glial cells are lost, we have identified a significant population of microglial cells, exclusively within the Henle fiber layer, which appear to ensheathe the Henle fibers, similar to that seen normally by Müller cells. Discussion: Since Müller cells synthesize retinal serine, whereas retinal neurons do not, we propose that serine deficiency, required for normal mitochondrial function, may relate to mitochondrial changes that underlie the development of MacTel. With mitochondrial changes occurring retina-wide, the question remains as to why the Müller cells are uniquely susceptible within the MacTel zone.
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A toolkit, developed by a multidisciplinary team of national and statewide professionals, was promoted among school nurses in Michigan to support use of the standards of care for asthma in schools. We evaluated the effectiveness of the toolkit to assist school nurses in providing support for students with asthma. We used a multimethod approach to assess use of the toolkit, changes in nursing practices as a result of using the toolkit, and challenges encountered when implementing the standards for asthma care. During a 12-month period, from July 2022 through June 2023, increases in time on web page and monthly page views aligned with efforts to promote toolkit use. School nurses reported using the toolkit and implementing practice changes pertaining to training and education, ensuring proper use of and access to asthma medications, and advocating for self-carry of asthma medications. Challenges to implementing the standards of asthma care were time, parental engagement, institutional support, and identifying students with asthma. We found that our promotional efforts prompted school nurses to access the toolkit, which helped school nurses to effectuate practice changes to improve support for students with asthma in schools.
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Asma , Serviços de Saúde Escolar , Serviços de Enfermagem Escolar , Humanos , Asma/enfermagem , Asma/terapia , Criança , Michigan , Guias de Prática Clínica como Assunto , Avaliação de Programas e Projetos de SaúdeRESUMO
Whereas excitation and inhibition of neurons are well understood, it is clear that neuromodulatory influences on neurons and their synapses play a major role in shaping neural activity in the brain. Memory and learning, emotional and other complex behaviors, as well as cognitive disorders have all been related to neuromodulatory mechanisms. A number of neuroactive substances including monoamines such as dopamine and neuropeptides have been shown to act as neuromodulators, but other substances thought to play very different roles in the body and brain act as neuromodulators, such as retinoic acid. We still understand little about how neuromodulatory substances exert their effects, and the present review focuses on how two such substances, dopamine and retinoic acid, exert their effects. The emphasis is on the underlying neuromodulatory mechanisms down to the molecular level that allow the second order bipolar cells and the output neurons of the retina, the ganglion cells, to respond to different environmental (ie lighting) conditions. The modulation described affects a simple circuit in the outer retina, involves several neuroactive substances and is surprisingly complex and not fully understood.
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BACKGROUND: To further strengthen the voice of patients, Europa Uomo initiated the Europa Uomo Patient Reported Outcome Study 2.0 (EUPROMS 2.0) in October 2021. OBJECTIVE: To collect the self-reported perspective of prostate cancer (PCa) patients on physical and mental well-being after PCa treatment outside a clinical trial setting to inform future fellow patients about the impact of PCa treatment. DESIGN, SETTING, AND PARTICIPANTS: Europa Uomo invited PCa patients to complete a cross-sectional survey including the validated EQ-5D-5L, EORTC-QLQ-C30, and the EPIC-26 questionnaires. Furthermore, the nine-item Shared Decision Making Questionnaire (SDM-Q-9) and diagnostic clinical scenarios were included. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Descriptive statistics was used to assess the demographic and clinical characteristics and to analyze the patient-reported outcome data. RESULTS AND LIMITATIONS: Between October 25, 2021 and January 17, 2022, 3571 men from 30 countries completed the EUPROMS 2.0 survey. The median age of respondents was 70 yr (interquartile range 65-75 yr). Half of the respondents underwent one treatment, most often radical prostatectomy. Men who are treated actively experience lower health-related quality of life than men on active surveillance, mainly regarding sexual function, fatigue, and insomnia. Lower urinary incontinence levels were seen for men who underwent radical prostatectomy (single treatment or in combination with other treatments). Of the respondents, 42% indicated that the determination of the prostate-specific antigen (PSA) value was part of a routine blood test; 25% wanted to undergo screening/early detection for PCa, and 20% indicated that the determination of the PSA value had a clinical reason. CONCLUSIONS: A large sample of 3571 international patients has contributed patient experience after PCa treatment in the EUPROMS 2.0 study, confirming that treatment for PCa mainly affects urinary incontinence, sexual function, fatigue, and insomnia. Such information can be used to direct toward a better patient-doctor relationship, to offer patients ready access to responsible information and a better understanding of their disease and treatment. PATIENT SUMMARY: Through the EUPROMS 2.0 survey, Europa Uomo has strengthened the voice of the patient. Such information can be used to inform future prostate cancer (PCa) patients about the impact of PCa treatment and to engage them in informed and shared decision-making.
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Neoplasias da Próstata , Distúrbios do Início e da Manutenção do Sono , Incontinência Urinária , Masculino , Humanos , Antígeno Prostático Específico , Qualidade de Vida , Estudos Transversais , Neoplasias da Próstata/cirurgia , Incontinência Urinária/epidemiologia , Medidas de Resultados Relatados pelo PacienteRESUMO
Immune checkpoint inhibitors that overcome T cell suppressive mechanisms in tumors have revolutionized the treatment of cancer but are only efficacious in a small subset of patients. Targeting suppressive mechanisms acting on innate immune cells could significantly improve the incidence of clinical response by facilitating a multi-lineage response against the tumor involving both adaptive and innate immune systems. Here, we show that intra-tumoral interleukin (IL)-38 expression is a feature of a large frequency of head and neck, lung and cervical squamous cancers and correlates with reduced immune cell numbers. We generated IMM20324, an antibody that binds human and mouse IL-38 proteins and inhibits the binding of IL-38 to its putative receptors, interleukin 1 receptor accessory protein-like 1 (IL1RAPL) and IL-36R. In vivo, IMM20324 demonstrated a good safety profile, delayed tumor growth in a subset of mice in an EMT6 syngeneic model of breast cancer, and significantly inhibited tumor expansion in a B16.F10 melanoma model. Notably, IMM20324 treatment resulted in the prevention of tumor growth following re-implantation of tumor cells, indicating the induction of immunological memory. Furthermore, exposure of IMM20324 correlated with decreased tumor volume and increased levels of intra-tumoral chemokines. Together, our data suggest that IL-38 is expressed in a high frequency of cancer patients and allows tumor cells to suppress anti-tumor immunity. Blockade of IL-38 activity using IMM20324 can re-activate immunostimulatory mechanisms in the tumor microenvironment leading to immune infiltration, the generation of tumor-specific memory and abrogation of tumor growth.
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Melanoma Experimental , Linfócitos T , Humanos , Camundongos , Animais , Melanoma Experimental/tratamento farmacológico , Memória Imunológica , Microambiente Tumoral , Linhagem Celular Tumoral , InterleucinasRESUMO
BACKGROUND: We aimed to quantify the difference in patient reported outcome (PRO) data between clinical studies and the (patient initiated) EUPROMS study for sexual functioning and urinary incontinence after radical prostatectomy (RP) and external beam radiotherapy (RT). METHODS: Europa Uomo, the patient organization of men with prostate cancer (PCa) in Europe, initiated the EUPROMS study. Data involved 1101 men with PCa treated with RP and 304 patients treated with RT. In a literature search we identified investigator-initiated studies which matched EUPROMS characteristics. The observed scores in the literature were compared to the scores calculated using the EUPROMS-models. Data from EUPROMS was used to develop four regression models for men treated with RP and RT. RESULTS: The time between diagnosis and questionnaire completion was estimated to be 3/4 years for men after RP, and 5 for RT. Eight studies were identified which reported PRO data using the EPIC with comparable follow-up. Large heterogeneity was observed in reported literature. For sexual function, the difference in calculated and observed scores is at most 24 points (range 3-24 points) and differences between studies were less evident; for urinary incontinence, the difference between calculated and observed scores is at most 15 points (range 1.5-15) (4 scores above the MID) and previous studies underreported the actual effect compared to the current study. CONCLUSIONS: Previous clinical investigator studies underreported the actual effect for urinary incontinence compared to the EUPROMS study. Clinicians should be aware of a potential underestimation of the reported PRO in the patient-physician communication.
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Neoplasias da Próstata , Incontinência Urinária , Masculino , Humanos , Qualidade de Vida , Neoplasias da Próstata/cirurgia , Incontinência Urinária/epidemiologia , Incontinência Urinária/etiologia , Micção , Medidas de Resultados Relatados pelo PacienteRESUMO
This paper reports an important breakthrough in partially restoring sight to a man who had lost his vision due to retinitis pigmentosa (RP), a heritable retinal degenerative disease that affects approximately 1 in 4000 people. Long considered an insurmountable challenge, a stellar team of vision scientists, engineers, basic biologists, and others, working together for many years, has enabled a man who had been legally blind for decades to begin distinguishing objects and navigating his environment1.
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Monoclonal antibodies are an efficacious therapy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, rapid viral mutagenesis led to escape from most of these therapies, outlining the need for an antibody cocktail with a broad neutralizing potency. Using an unbiased interrogation of the memory B cell repertoire of patients with convalescent COVID-19, we identified human antibodies with broad antiviral activity in vitro and efficacy in vivo against all tested SARS-CoV-2 variants of concern, including Delta and Omicron BA.1 and BA.2. Here, we describe an antibody cocktail, IMM-BCP-01, that consists of three patient-derived broadly neutralizing antibodies directed at nonoverlapping surfaces on the SARS-CoV-2 Spike protein. Two antibodies, IMM20184 and IMM20190, directly blocked Spike binding to the ACE2 receptor. Binding of the third antibody, IMM20253, to its cryptic epitope on the outer surface of RBD altered the conformation of the Spike Trimer, promoting the release of Spike monomers. These antibodies decreased Omicron SARS-CoV-2 infection in the lungs of Syrian golden hamsters in vivo and potently induced antiviral effector response in vitro, including phagocytosis, ADCC, and complement pathway activation. Our preclinical data demonstrated that the three-antibody cocktail IMM-BCP-01 could be a promising means for preventing or treating infection of SARS-CoV-2 variants of concern, including Omicron BA.1 and BA.2, in susceptible individuals.
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COVID-19 , SARS-CoV-2 , Animais , Anticorpos Antivirais , Cricetinae , Humanos , Glicoproteína da Espícula de Coronavírus/genéticaRESUMO
Low birth weight is a risk factor for chronic kidney disease, whereas adult podocyte depletion is a key event in the pathogenesis of glomerulosclerosis. However, whether low birth weight due to poor maternal nutrition is associated with low podocyte endowment and glomerulosclerosis in later life is not known. Female Sprague-Dawley rats were fed a normal-protein diet (NPD; 20%) or low-protein diet (LPD; 8%), to induce low birth weight, from 3 wk before mating until postnatal day 21 (PN21), when kidneys from some male offspring were taken for quantitation of podocyte number and density in whole glomeruli using immunolabeling, tissue clearing, and confocal microscopy. The remaining offspring were fed a normal- or high-fat diet until 6 mo to induce catch-up growth and excessive weight gain, respectively. At PN21, podocyte number per glomerulus was 15% lower in low birth weight (LPD) than normal birth weight (NPD) offspring, with this deficit greater in outer glomeruli. Surprisingly, podocyte number in LPD offspring increased in outer glomeruli between PN21 and 6 mo, although an overall 9% podocyte deficit persisted. Postnatal fat feeding to LPD offspring did not alter podometric indexes or result in glomerular pathology at 6 mo, whereas fat feeding in NPD offspring was associated with far greater body and fat mass as well as podocyte loss, reduced podocyte density, albuminuria, and glomerulosclerosis. This is the first report that maternal diet can influence podocyte endowment. Our findings provide new insights into the impact of low birth weight, podocyte endowment, and postnatal weight on podometrics and kidney health in adulthood.NEW & NOTEWORTHY The present study shows, for the first time, that low birth weight as a result of maternal nutrition is associated with low podocyte endowment. However, a mild podocyte deficit at birth did not result in glomerular pathology in adulthood. In contrast, postnatal podocyte loss in combination with excessive body weight led to albuminuria and glomerulosclerosis. Taken together, these findings provide new insights into the associations between birth weight, podocyte indexes, postnatal weight, and glomerular pathology.
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Tamanho Corporal/fisiologia , Nefropatias/patologia , Podócitos/patologia , Efeitos Tardios da Exposição Pré-Natal/patologia , Animais , Peso ao Nascer/fisiologia , Feminino , Rim/patologia , Glomérulos Renais/patologia , Gravidez , Ratos Sprague-DawleyRESUMO
Patients who recover from SARS-CoV-2 infections produce antibodies and antigen-specific T cells against multiple viral proteins. Here, an unbiased interrogation of the anti-viral memory B cell repertoire of convalescent patients has been performed by generating large, stable hybridoma libraries and screening thousands of monoclonal antibodies to identify specific, high-affinity immunoglobulins (Igs) directed at distinct viral components. As expected, a significant number of antibodies were directed at the Spike (S) protein, a majority of which recognized the full-length protein. These full-length Spike specific antibodies included a group of somatically hypermutated IgMs. Further, all but one of the six COVID-19 convalescent patients produced class-switched antibodies to a soluble form of the receptor-binding domain (RBD) of S protein. Functional properties of anti-Spike antibodies were confirmed in a pseudovirus neutralization assay. Importantly, more than half of all of the antibodies generated were directed at non-S viral proteins, including structural nucleocapsid (N) and membrane (M) proteins, as well as auxiliary open reading frame-encoded (ORF) proteins. The antibodies were generally characterized as having variable levels of somatic hypermutations (SHM) in all Ig classes and sub-types, and a diversity of VL and VH gene usage. These findings demonstrated that an unbiased, function-based approach towards interrogating the COVID-19 patient memory B cell response may have distinct advantages relative to genomics-based approaches when identifying highly effective anti-viral antibodies directed at SARS-CoV-2.
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BACKGROUND: Europa Uomo initiated the Europa Uomo Patient Reported Outcome Study (EUPROMS) to collect prostate cancer (PCa) patient-reported outcome (PRO) data as a primary endpoint. OBJECTIVE: To inform future PCa patients about the impact of PCa treatment through self-reported PRO data of fellow patients collected outside a clinical trial setting. DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional survey was conducted among PCa patients currently receiving or having received treatment. The EUPROMS survey contained the EQ-5D-5 L (generic health), the EORTC-QLQ-C30 (cancer-specific quality of life (QoL), and the Expanded Prostate cancer Index Composite short form 26 (EPIC-26; prostate-specific health) questionnaires. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Descriptive statistics were used to assess the demographic and clinical characteristics, and to analyze the PROs of EQ-5D-5L, EORTC-QLQ-C30, and EPIC-26. RESULTS AND LIMITATIONS: Between August 21 and November 19, 2019, 2943 men from 24 European countries completed the EUPROMS survey. The median age of the respondents was 71 yr (interquartile range 65-75 yr); 81.9% was living with a spouse. In total, 1937 (65.8%) men underwent a single treatment, and 636 (21.6%), 300 (10.2%), and 70 (2.4%) underwent two, three, and four treatments, respectively. Fatigue scores are highest for men who underwent radiotherapy or chemotherapy. Progression of disease leads to more insomnia. Surgery affects urinary incontinence the most. Self-reported sexual function amounts to 27/100, with the lowest scores being reported for men who underwent surgery and radiotherapy (15/100). Overall, patients who received two or more treatments reported lower scores for all indices. CONCLUSIONS: The EUPROMS survey provided a cross-sectional picture of the current PCa patient population and their reported QoL. Initial treatment is often followed by subsequent treatments, affecting mainly sexual function, as well as fatigue and insomnia. QoL of men undergoing chemotherapy is worse for almost all domains. These data can inform physicians and patients on the true impact of PCa treatment. PATIENT SUMMARY: Patient-reported quality of life in the Europa Uomo Patient Reported Outcome Study (EUPROMS) survey-a more informal setting as compared with clinical trials-reveals that prostate cancer treatment affects mainly sexual function, fatigue, and insomnia.
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Neoplasias da Próstata , Distúrbios do Início e da Manutenção do Sono , Estudos Transversais , Fadiga , Humanos , Masculino , Medidas de Resultados Relatados pelo Paciente , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/terapia , Qualidade de Vida , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: The COVID-19 pandemic poses significant challenges to healthcare facilities and as per social distancing measures, many consultations are now being carried out via means of telemedicine. As some urologists may not be skilled with remote consultations, there is a need for recommendations on patient-centered online medical counseling. MATERIAL AND METHODS: We have identified eight areas of excellence and defined the principles based on our experience. RESULTS: A professional setting should be provided, in which the privacy of the patient can be ensured. Accompanying persons should be encouraged into the consultation. Proper introduction could serve not only to verify the personality of the patient, but also to provide them with a sense of confidentiality. The interview should be held in a way to overcome the limitations of non-physical encounters, and pande-mic-specific issues should be taken into consideration. When arranging plans, the physician should judge accordingly in regards to what type of management is inevitable or safe, as well as available at this point; strict follow-up should be arranged. As home isolation may lead to unfavorable changes in lifestyle, this issue should be addressed too. The patient should be guided on how to self-educate. Concluding the visit should be aimed at proper evaluation of the patient's comprehension of the consultation. CONCLUSIONS: It is vital to pursue consistency in providing care to patients. While online counseling may seem challenging, if one adheres to the principles of patient-centered practice, telemedicine may become a valuable tool in maintaining the best-quality care amid the ongoing pandemic.
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Purpose: Although zebrafish rods begin to develop as early as 2 days postfertilization (dpf), they are not deemed anatomically mature and functional until 15 to 21 dpf. A recent study detected a small electroretinogram (ERG) from rods in a cone mutant called no optokinetic response f (nof) at 5 dpf, suggesting that young rods are functional. Whether they can mediate behavioral responses in larvae is unknown. Methods: We first confirmed rod function by measuring nof ERGs under photopic and scotopic illumination at 6 dpf. We evaluated the role of rods in visual behaviors using two different assays: the visual-motor response (VMR) and optokinetic response (OKR). We measured responses from wild-type (WT) larvae and nof mutants under photopic and scotopic illuminations at 6 dpf. Results: Nof mutants lacked a photopic ERG. However, after prolonged dark adaptation, they displayed scotopic ERGs. Compared with WT larvae, the nof mutants displayed reduced VMRs. The VMR difference during light onset gradually diminished with decreased illumination and became nearly identical at lower light intensities. Additionally, light-adapted nof mutants did not display an OKR, whereas dark-adapted nof mutants displayed scotopic OKRs. Conclusions: Because the nof mutants lacked a photopic ERG but displayed scotopic ERGs after dark adaptation, the mutants clearly had functional rods. WT larvae and the nof mutants displayed comparable scotopic light-On VMRs and scotopic OKRs after dark adaptation, suggesting that these responses were driven primarily by rods. Together, these observations indicate that rods contribute to zebrafish visual behaviors as early as 6 dpf.
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Células Fotorreceptoras Retinianas Bastonetes/fisiologia , Visão Ocular/fisiologia , Peixe-Zebra/fisiologia , Animais , Visão de Cores/fisiologia , Eletrorretinografia , Técnicas de Genotipagem , Larva , Visão Noturna/fisiologia , Nistagmo Optocinético/fisiologiaRESUMO
Macular telangiectasia type 2 (MacTel), a late-onset macular degeneration, has been linked to a loss in the retina of Müller glial cells and the amino acid serine, synthesized by the Müller cells. The disease is confined mainly to a central retinal region called the MacTel zone. We have used electron microscopic connectomics techniques, optimized for disease analysis, to study the retina from a 48-y-old woman suffering from MacTel. The major observations made were specific changes in mitochondrial structure within and outside the MacTel zone that were present in all retinal cell types. We also identified an abrupt boundary of the MacTel zone that coincides with the loss of Müller cells and macular pigment. Since Müller cells synthesize retinal serine, we propose that a deficiency of serine, required for mitochondrial maintenance, causes mitochondrial changes that underlie MacTel development.
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Conectoma/métodos , Retina , Doenças Retinianas , Feminino , Humanos , Degeneração Macular/diagnóstico por imagem , Degeneração Macular/patologia , Microscopia Eletrônica , Pessoa de Meia-Idade , Retina/citologia , Retina/diagnóstico por imagem , Retina/patologia , Doenças Retinianas/diagnóstico por imagem , Doenças Retinianas/patologiaRESUMO
Laminin alpha 5 (LAMA5) is a member of a large family of proteins that trimerise and then polymerise to form a central component of all basement membranes. Consequently, the protein plays an instrumental role in shaping the normal development of the kidney, skin, neural tube, lung and limb, and many other organs and tissues. Pathogenic mutations in some laminins have been shown to cause a range of largely syndromic conditions affecting the competency of the basement membranes to which they contribute. We report the identification of a mutation in the polymerisation domain of LAMA5 in a patient with a complex syndromic disease characterised by defects in kidney, craniofacial and limb development, and by a range of other congenital defects. Using CRISPR-generated mouse models and biochemical assays, we demonstrate the pathogenicity of this variant, showing that the change results in a failure of the polymerisation of α/ß/γ laminin trimers. Comparing these in vivo phenotypes with those apparent upon gene deletion in mice provides insights into the specific functional importance of laminin polymerisation during development and tissue homeostasis.
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Deficiências do Desenvolvimento/genética , Desenvolvimento Fetal , Laminina/genética , Mutação/genética , Polimerização , Sequência de Aminoácidos , Animais , Animais Recém-Nascidos , Pré-Escolar , Deficiências do Desenvolvimento/patologia , Feto/embriologia , Humanos , Hidronefrose/patologia , Recém-Nascido , Rim/anormalidades , Rim/embriologia , Rim/patologia , Laminina/química , Pulmão/anormalidades , Pulmão/embriologia , Pulmão/patologia , Masculino , Camundongos , Domínios Proteicos , SíndromeAssuntos
Cegueira/etiologia , Cegueira/terapia , Células Fotorreceptoras de Vertebrados/patologia , Doenças Retinianas/complicações , Doenças Retinianas/terapia , Transplante de Células , Terapia Genética/métodos , Humanos , Optogenética/métodos , Células Fotorreceptoras de Vertebrados/transplante , Próteses e Implantes , Doenças Retinianas/genética , Visão OcularRESUMO
The recognition that a dietary factor is essential to maintain good and sensitive vision as well as overall health goes back over 3,000 years to the ancient Egyptians. With the discovery of the vitamins at the turn of the twentieth century, fat-soluble vitamin A was soon shown to be the essential factor. In the first half of the twentieth century, the role vitamin A plays in vision, as precursor to the light-sensitive visual pigment molecules in the photoreceptors was elegantly worked out, especially by George Wald and his colleagues. Beginning in the 1960s, with the recognition of the active metabolite of vitamin A, its acid form now called retinoic acid, the roles of vitamin A in maintaining overall health of an organism began to be explored, and this research continues to this day. Receptors activated by retinoic acid, the RARs and RXRs have been shown to regulate gene transcription in a surprisingly wide variety of biological processes from early growth and development to the maintenance of epithelial tissues in many organs, the regulation of the immune system, and even the modulation of synaptic function in the brain involved in mechanisms underlying memory and learning. Therapeutic uses for retinoic acid have been developed, including one for a specific form of leukemia. The story is by no means complete and it is likely more surprises await with regard to this remarkable molecule.
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Plasticidade Neuronal/fisiologia , Visão Ocular/fisiologia , Vitamina A/metabolismo , Humanos , Lactente , Mortalidade Infantil , Receptores do Ácido Retinoico/metabolismo , Transdução de Sinais/fisiologiaRESUMO
RIPK1 has emerged as a key effector in programmed necrosis or necroptosis. This function of RIPK1 is mediated by its protein serine/threonine kinase activity and through the downstream kinase RIPK3. Deletion of RIPK1 prevents embryonic lethality in mice lacking FADD, a signaling adaptor protein required for activation of Caspase 8 in extrinsic apoptotic pathways. This indicates that FADD-mediated apoptosis inhibits RIPK1-dependent necroptosis to ensure successful embryogenesis. However, the molecular mechanism for this critical regulation remains unclear. In the current study, a novel mouse model has been generated, by disrupting a potential caspase cleavage site at aspartic residue (D)324 in RIPK1. Interestingly, replacing D324 with alanine (A) in RIPK1 results in midgestation lethality, similar to the embryonic defect in FADD-/- mice but in stark contrast to the normal embryogenesis of RIPK1-/- null mutant mice. Surprisingly, disrupting the downstream RIPK3 alone is insufficient to rescue RIPK1D324A/D324A mice from embryonic lethality, unless FADD is deleted simultaneously. Further analyses reveal a paradoxical role for RIPK1 in promoting caspase activation and apoptosis in embryos, a novel mechanism previously unappreciated.
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Apoptose/genética , Desenvolvimento Embrionário/genética , Necroptose/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Animais , Apoptose/efeitos dos fármacos , Caspase 8/metabolismo , Proteína de Domínio de Morte Associada a Fas/genética , Fibroblastos , Genes Letais , Linfadenopatia/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Necroptose/efeitos dos fármacos , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Esplenomegalia/genética , Linfócitos T , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
TRADD is an adaptor for TNFR1-induced apoptosis and NFκB activation. However, TRADD-deficient mice undergo normal development and contain normal lymphoid populations, which contrasts with an embryonic defect in mice lacking FADD, the shared adaptor mediating apoptosis. Recent studies indicate FADD suppresses embryonic necroptosis mediated by RIPK1. TRADD was suggested to also mediate necroptosis. Here we report that targeting TRADD fails to rescue Fadd-/- embryos from necroptosis, and ablation of TRADD rescues Ripk1-/- mice from perinatal lethality when RIPK3-mediated necroptosis is disabled. The resulting Ripk1-/-Ripk3-/-Tradd-/- mice survive until early adulthood, but die thereafter. A single allele of Tradd is optimal for survival of Ripk1-/-Ripk3-/-Tradd+/- mice. We show that TRADD plays a more dominating role in NFκB-signaling than RIPK1. While RIPK1 protects thymocytes from TNFα-induced apoptosis, TRADD promotes this process. The data demonstrate that TRADD is critical in perinatal and adult mice lacking RIPK1 and RIPK3, which has not been appreciated in prior studies.