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1.
Int Arch Allergy Immunol ; 185(2): 190-195, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37952519

RESUMEN

INTRODUCTION: Chronic spontaneous urticaria (CSU) with autoreactivity is often resistant to antihistamines. Autologous whole blood injection (AWBI) has shown potential efficacy in the treatment of this disease, but it is controversial. It is necessary to screen patients who are suitable for this therapy in advance. This study aimed to identify biomarkers that predict the efficacy of AWBI treatment in CSU patients with autoreactivity. METHODS: A total of 30 patients with autologous serum skin test-positive CSU treated with AWBI were included in this study; urticaria activity score (UAS7) was recorded and the treatment response was judged based on it. Levels of total serum IgE, anti-high-affinity IgE receptor (FcεRI) IgG, and basophils CD63 and FcεRI expressions, and D-dimer of all patients were determined and analyzed. RESULTS: Baseline levels of total IgE, D-dimer, basophil FcεRI and CD63 expressions showed good correlations with UAS7 variations. D-dimer, basophil FcεRI and CD63 expressions changed significantly before and after AWBI treatment in AWBI responders, and the basophil FcεRI and CD63 expressions consistently and dynamically decreased in AWBI responders during the treatment. Baseline levels of total IgE, D-dimer, basophil FcεRI and CD63 expressions showed certain predictive values for AWBI response. CONCLUSIONS: Baseline levels of total IgE, D-dimer, basophil FcεRI and CD63 expressions could be biomarkers of predicting AWBI efficacy in patients with CSU with autoreactivity.


Asunto(s)
Urticaria Crónica , Urticaria , Humanos , Inmunoglobulina E , Receptores de IgE/metabolismo , Urticaria/terapia , Urticaria/metabolismo , Basófilos/metabolismo , Biomarcadores/metabolismo , Enfermedad Crónica
2.
Int Arch Allergy Immunol ; 185(1): 79-83, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37844549

RESUMEN

BACKGROUND: Acute urticaria (AU) may be associated with atopy, but the relationship between atopic status and the clinical features of the disease has not been fully described. OBJECTIVES: The aim of the study was to determine the proportion of atopy in AU patients and to see whether atopy is related to the clinical characteristics of AU and whether it has an impact on the outcome of the disease. MATERIALS AND METHOD: A retrospective analysis of patients with AU was performed. Demographic data, clinical features, and laboratory results were compared and analyzed between the atopic and non-atopic AU (napAU). RESULTS: In total, 139 participants were included. 54 (38.8%) patients were atopic AU (apAU) and 85 (61.2%) were napAU. Compared with napAU patients, apAU patients were more likely to have anaphylaxis, higher levels of C4, and lower levels of antistreptolysin. There were no significant differences between the two groups in terms of other clinical features, laboratory tests, the natural course of the disease, or disease outcomes. CONCLUSION: Atopy does exist in some patients with AU, and AU patients with an atopic background are at higher risk for anaphylaxis. Atopy does not influence the clinical outcome of AU and is not correlated with other clinical features and laboratory results of AU.


Asunto(s)
Anafilaxia , Hipersensibilidad Inmediata , Urticaria , Humanos , Estudios Retrospectivos , Inmunoglobulina E
4.
Dev Dyn ; 245(7): 727-38, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26661417

RESUMEN

Retinal dystrophies are a major cause of blindness for which there are currently no curative treatments. Transplantation of stem cell-derived neuronal progenitors to replace lost cells has been widely investigated as a therapeutic option. Another promising strategy would be to trigger self-repair mechanisms in patients, through the recruitment of endogenous cells with stemness properties. Accumulating evidence in the past 15 year0s has revealed that several retinal cell types possess neurogenic potential, thus opening new avenues for regenerative medicine. Among them, Müller glial cells have been shown to be able to undergo a reprogramming process to re-acquire a stem/progenitor state, allowing them to proliferate and generate new neurons for repair following retinal damages. Although Müller cell-dependent spontaneous regeneration is remarkable in some species such as the fish, it is extremely limited and ineffective in mammals. Understanding the cellular events and molecular mechanisms underlying Müller cell activities in species endowed with regenerative capacities could provide knowledge to unlock the restricted potential of their mammalian counterparts. In this context, the present review provides an overview of Müller cell responses to injury across vertebrate model systems and summarizes recent advances in this rapidly evolving field. Developmental Dynamics 245:727-738, 2016. © 2015 The Authors. Developmental Dynamics published by Wiley Periodicals, Inc.


Asunto(s)
Células Ependimogliales/citología , Células Ependimogliales/fisiología , Retina/citología , Animales , Células Ependimogliales/metabolismo , Humanos , Regeneración/genética , Regeneración/fisiología , Retina/metabolismo , Células Madre/citología , Células Madre/metabolismo , Células Madre/fisiología
5.
Proc Natl Acad Sci U S A ; 110(47): E4520-9, 2013 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-24191003

RESUMEN

Ciliary neurotrophic factor (CNTF) acts as a potent neuroprotective agent in multiple retinal degeneration animal models. Recently, CNTF has been evaluated in clinical trials for the inherited degenerative disease retinitis pigmentosa (RP) and for dry age-related macular degeneration (AMD). Despite its potential as a broad-spectrum therapeutic treatment for blinding diseases, the target cells of exogenous CNTF and its mechanism of action remain poorly understood. We have shown previously that constitutive expression of CNTF prevents photoreceptor death but alters the retinal transcriptome and suppresses visual function. Here, we use a lentivirus to deliver the same secreted human CNTF used in clinical trials to a mouse model of RP. We found that low levels of CNTF halt photoreceptor death, improve photoreceptor morphology, and correct opsin mislocalization. However, we did not detect corresponding improvement of retinal function as measured by the electroretinogram. Disruption of the cytokine receptor gp130 gene in Müller glia reduces CNTF-dependent photoreceptor survival and prevents phosphorylation of STAT3 and ERK in Müller glia and the rest of the retina. Targeted deletion of gp130 in rods also demolishes neuroprotection by CNTF and prevents further activation of Müller glia. Moreover, CNTF elevates the expression of LIF and endothelin 2, thus positively promoting Müller and photoreceptor interactions. We propose that exogenous CNTF initially targets Müller glia, and subsequently induces cytokines acting through gp130 in photoreceptors to promote neuronal survival. These results elucidate a cellular mechanism for exogenous CNTF-triggered neuroprotection and provide insight into the complex cellular responses induced by CNTF in diseased retinas.


Asunto(s)
Factor Neurotrófico Ciliar/metabolismo , Receptor gp130 de Citocinas/metabolismo , Células Ependimogliales/metabolismo , Células Fotorreceptoras de Vertebrados/metabolismo , Degeneración Retiniana/tratamiento farmacológico , Transducción de Señal/fisiología , Análisis de Varianza , Animales , Western Blotting , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Humanos , Inmunohistoquímica , Lentivirus , Ratones , Ratones Transgénicos , Microscopía Electrónica de Transmisión , Reacción en Cadena en Tiempo Real de la Polimerasa , Degeneración Retiniana/genética
6.
Opt Express ; 22(16): 19610-20, 2014 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-25321044

RESUMEN

Based on the framework of spin-flip model (SFM), the output characteristics of a 1550 nm vertical-cavity surface-emitting laser (VCSEL) subject to variable-polarization fiber Bragg grating (FBG) feedback (VPFBGF) have been investigated. With the aid of the self-correlation function (SF) and the permutation entropy (PE) function, the time-delay signature (TDS) of chaos in the VPFBGF-VCSEL is evaluated, and then the influences of the operation parameters on the TDS of chaos are analyzed. The results show that the TDS of chaos can be suppressed efficiently through selecting suitable coupling coefficient and feedback rate of the FBG, and is weaker than that of chaos generated by traditional variable-polarization mirror feedback VCSELs (VPMF-VCSELs) or polarization-preserved FBG feedback VCSELs (PPFBGF-VCSELs).

7.
Front Immunol ; 15: 1279976, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38380314

RESUMEN

Chronic urticaria (CU) is one of the most common dermatological diseases and has a significant impact on the quality of life of patients. However, the pathogenesis of this disease remains unclear. Autoimmunity in chronic spontaneous urticaria (CSU) has received considerable attention and has been studied previously. Atopy is an important characteristic of CU; however, it has not been fully recognized. Atopy predisposes individuals to immune responses to allergens, leading to type 2 inflammation and immunoglobulin E (IgE) overproduction. Compared with healthy individuals, patients with CU have a higher proportion of atopy, and an atopic background is correlated with the clinical characteristics of CU. The total IgE levels in patients with CU is significantly higher than those in healthy individuals. Although its level is not higher than that in classic allergic diseases, it is closely related to CU. Exogenous allergens, auto-allergens, and specific IgEs, which are closely related to atopy, have been reported, and their roles in CU pathogenesis are also being studied. Local and systemic atopic inflammation is present in patients with CU. This review summarizes the current knowledge regarding atopy and CU, speculating that there are CU subtypes, such as atopic CSU or atopic chronic inducible urticaria (CIndU) and that atopy may be involved in the pathogenesis of CU. These findings provide a new perspective for a comprehensive understanding of the clinical features of CU and further research regarding its pathogenesis.


Asunto(s)
Urticaria Crónica , Hipersensibilidad Inmediata , Urticaria , Humanos , Calidad de Vida , Hipersensibilidad Inmediata/complicaciones , Alérgenos , Inmunoglobulina E , Inflamación/complicaciones
8.
Mol Cell Neurosci ; 49(2): 171-83, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22155156

RESUMEN

The lipid phosphatase PTEN is a critical negative regulator of extracellular signal-induced PI3K activities, yet the roles of PTEN in the neural retina remain poorly understood. Here, we investigate the function of PTEN during retinal development. Deletion of Pten at the onset of neurogenesis in retinal progenitors results in the reduction of retinal ganglion cells and rod photoreceptors, but increased Müller glial genesis. In addition, PTEN deficiency leads to elevated phosphorylation of Akt, especially in the developing inner plexiform layer, where high levels of PTEN are normally expressed. In Pten mutant retinas, various subtypes of amacrine cells show severe dendritic overgrowth, causing specific expansion of the inner plexiform layer. However, the outer plexiform layer remains relatively undisturbed in the Pten deficient retina. Physiological analysis detects reduced rod function and augmented oscillatory potentials originating from amacrine cells in Pten mutants. Furthermore, deleting Pten or elevating Akt activity in individual amacrine cells is sufficient to disrupt dendritic arborization, indicating that Pten activity is required cell autonomously to control neuronal morphology. Moreover, inhibiting endogenous Akt activity attenuates inner plexiform layer formation in vitro. Together, these findings demonstrate that suppression of PI3K/Akt signaling by PTEN is crucial for proper neuronal differentiation and normal retinal network formation.


Asunto(s)
Interneuronas/fisiología , Fosfohidrolasa PTEN/fisiología , Retina/citología , Células Amacrinas/citología , Animales , Técnicas de Inactivación de Genes , Interneuronas/citología , Ratones , Ratones Endogámicos C57BL , Morfogénesis/genética , Morfogénesis/fisiología , Mutación/genética , Neurogénesis/genética , Neurogénesis/fisiología , Neuronas/metabolismo , Neuronas/fisiología , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/metabolismo , Retina/crecimiento & desarrollo , Células Ganglionares de la Retina/clasificación , Células Ganglionares de la Retina/citología , Células Fotorreceptoras Retinianas Bastones/fisiología , Transducción de Señal/genética , Transducción de Señal/fisiología
9.
J Dermatol ; 50(8): 1063-1067, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36938687

RESUMEN

Symptomatic dermographism (SD) is the most common form of chronic inducible urticarias. The etiology of this disease has rarely been reported in the literature. Minocycline is widely used in the treatment of acne, rosacea, and other inflammatory skin diseases. Herein we report four cases of SD onset during minocycline administration. These were young women in their 20s to 30s who were taking minocycline orally for acne vulgaris or rosacea. They all experienced the onset of SD 2-3 weeks after taking the drug, and then the complete disappearance of SD 1 month after stopping the drug. Minocycline was thought to be the culprit drug in these cases as other drugs were ruled out on clinical grounds. Our small series suggests that oral minocycline may induce SD, thus raising the awareness of this association in clinical practice. More research is needed to further confirm this association and reveal the underlying mechanism(s).


Asunto(s)
Acné Vulgar , Rosácea , Urticaria , Femenino , Humanos , Minociclina/uso terapéutico , Antibacterianos/efectos adversos , Urticaria Crónica Inducible , Acné Vulgar/tratamiento farmacológico , Rosácea/inducido químicamente , Rosácea/tratamiento farmacológico , Urticaria/tratamiento farmacológico
10.
Int Immunopharmacol ; 125(Pt A): 111137, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37897946

RESUMEN

Subcutaneous immunotherapy (SCIT) and dupilumab are important treatments for patients with moderate to severe atopic dermatitis (AD). However, in clinical practice, poor response to allergen immunotherapy (AIT) or dupilumab has been observed in some patients. It is unknown whether combining dupilumab and SCIT can improve treatment responses in patients with moderate to severe AD that is resistant to dupilumab or SCIT monotherapy. This single-centre, retrospective, observational, real-world study evaluated the efficacy and safety of dupilumab and SCIT for refractory moderate to severe AD. The data of ten patients with moderate to severe atopic dermatitis who were treated with dupilumab and SCIT were retrospectively analysed. The scoring atopic dermatitis (SCORAD) score, numerical rating scale (NRS), and atopic dermatitis control test (ADCT) scores and eosinophil and total IgE levels before and after add-on therapy were compared and analysed. The SCORAD, NRS, and ADCT scores decreased significantly at four and 12 weeks after the initiation of add-on therapy and plateaued during maintenance treatment. The eosinophil and total IgE levels were not significantly different before and after add-on therapy. No serious adverse reactions were reported in any patient during add-on therapy. This study indicates that the combination of dupilumab and SCIT safely improves the treatment response of patients with moderate to severe AD who are resistant to dupilumab or SCIT monotherapy.


Asunto(s)
Dermatitis Atópica , Humanos , Estudios Retrospectivos , Dermatitis Atópica/tratamiento farmacológico , Resultado del Tratamiento , Inyecciones Subcutáneas , Desensibilización Inmunológica , Inmunoglobulina E , Índice de Severidad de la Enfermedad , Método Doble Ciego
11.
Front Genet ; 14: 1251216, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37745862

RESUMEN

Dominant optic atrophy (DOA) is an inherited disease that leads to the loss of retinal ganglion cells (RGCs), the projection neurons that relay visual information from the retina to the brain through the optic nerve. The majority of DOA cases can be attributed to mutations in optic atrophy 1 (OPA1), a nuclear gene encoding a mitochondrial-targeted protein that plays important roles in maintaining mitochondrial structure, dynamics, and bioenergetics. Although OPA1 is ubiquitously expressed in all human tissues, RGCs appear to be the primary cell type affected by OPA1 mutations. DOA has not been extensively studied in human RGCs due to the general unavailability of retinal tissues. However, recent advances in stem cell biology have made it possible to produce human RGCs from pluripotent stem cells (PSCs). To aid in establishing DOA disease models based on human PSC-derived RGCs, we have generated iPSC lines from two DOA patients who carry distinct OPA1 mutations and present very different disease symptoms. Studies using these OPA1 mutant RGCs can be correlated with clinical features in the patients to provide insights into DOA disease mechanisms.

12.
Hum Mol Genet ; 19(21): 4229-38, 2010 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-20709808

RESUMEN

Age-related macular degeneration (AMD) is characterized by the loss or dysfunction of retinal pigment epithelium (RPE) and is the most common cause of vision loss among the elderly. Stem-cell-based strategies, using human embryonic stem cells (hESCs) or human-induced pluripotent stem cells (hiPSCs), may provide an abundant donor source for generating RPE cells in cell replacement therapies. Despite a significant amount of research on deriving functional RPE cells from various stem cell sources, it is still unclear whether stem-cell-derived RPE cells fully mimic primary RPE cells. In this report, we demonstrate that functional RPE cells can be derived from multiple lines of hESCs and hiPSCs with varying efficiencies. Stem-cell-derived RPE cells exhibit cobblestone-like morphology, transcripts, proteins and phagocytic function similar to human fetal RPE (fRPE) cells. In addition, we performed global gene expression profiling of stem-cell-derived RPE cells, native and cultured fRPE cells, undifferentiated hESCs and fibroblasts to determine the differentiation state of stem-cell-derived RPE cells. Our data indicate that hESC-derived RPE cells closely resemble human fRPE cells, whereas hiPSC-derived RPE cells are in a unique differentiation state. Furthermore, we identified a set of 87 signature genes that are unique to human fRPE and a majority of these signature genes are shared by stem-cell-derived RPE cells. These results establish a panel of molecular markers for evaluating the fidelity of human pluripotent stem cell to RPE conversion. This study contributes to our understanding of the utility of hESC/hiPSC-derived RPE in AMD therapy.


Asunto(s)
Epitelio Pigmentado de la Retina/metabolismo , Células Madre/metabolismo , Envejecimiento/genética , Western Blotting , Línea Celular , Perfilación de la Expresión Génica , Humanos , Inmunohistoquímica , Degeneración Macular/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Fagocitosis , Epitelio Pigmentado de la Retina/citología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Madre/citología
13.
Clin Cosmet Investig Dermatol ; 15: 1429-1434, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35924254

RESUMEN

Chronic non-healing ulcers are the undesirable outcome of delayed wound healing influenced by many factors. It can be seen in patients with diabetes, autoimmune conditions and multiple primary skin conditions. But chronic non-healing ulcers secondary to atopic inflammation are rarely reported in the literature. In this study, we reported a case with wounds caused by the wrong tattoo and surgery, activation of atopic inflammation caused delayed wound healing and the formation of chronic non-healing ulcers. The patient's atopic inflammation was relieved and stabilized with oral cyclosporine and topical application of halometasone cream and subsequently 0.1% tacrolimus cream, and then the chronic non-healing ulcers healed well, without recurrence at a follow-up visit 3 months later.

14.
Clin Cosmet Investig Dermatol ; 15: 2541-2546, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36466946

RESUMEN

Acute generalized pustular psoriasis (GPP) is a severe but rare variant of psoriasis, characterized by an acute eruption of extensive erythema with numerous non-follicular pustules. In rare cases, local pustular psoriasis like acrodermatitis continua of Hallopeau (ACH) may progress into acute GPP if improperly treated. ACH and GPP are rare in the clinic and their treatment is more complex and often treatment-resistant compared to psoriasis vulgaris (PV). A variety of anti-psoriasis biologics emerging in recent years have been reported for the treatment of ACH and acute GPP. Biologics is considered to be an upgraded treatment option for traditional anti-psoriasis agents. But there are few reports of GPP patients developing resistance to biologics, or what if biologics fails. Herein, we report a case of acute GPP that developed from ACH, initially responded extremely well to adalimumab, but the treatment failed when the patient treated with the drug again, which is thought to have developed resistance to adalimumab, finally successfully treated with narrowband ultraviolet B (NB-UVB) and acitretin.

15.
Nat Commun ; 13(1): 7037, 2022 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-36396639

RESUMEN

Ciliary neurotrophic factor (CNTF) acts as a potent neuroprotective cytokine in multiple models of retinal degeneration. To understand mechanisms underlying its broad neuroprotective effects, we have investigated the influence of CNTF on metabolism in a mouse model of photoreceptor degeneration. CNTF treatment improves the morphology of photoreceptor mitochondria, but also leads to reduced oxygen consumption and suppressed respiratory chain activities. Molecular analyses show elevated glycolytic pathway gene transcripts and active enzymes. Metabolomics analyses detect significantly higher levels of ATP and the energy currency phosphocreatine, elevated glycolytic pathway metabolites, increased TCA cycle metabolites, lipid biosynthetic pathway intermediates, nucleotides, and amino acids. Moreover, CNTF treatment restores the key antioxidant glutathione to the wild type level. Therefore, CNTF significantly impacts the metabolic status of degenerating retinas by promoting aerobic glycolysis and augmenting anabolic activities. These findings reveal cellular mechanisms underlying enhanced neuronal viability and suggest potential therapies for treating retinal degeneration.


Asunto(s)
Factor Neurotrófico Ciliar , Degeneración Retiniana , Ratones , Animales , Factor Neurotrófico Ciliar/genética , Factor Neurotrófico Ciliar/metabolismo , Degeneración Retiniana/terapia , Neuroprotección , Retina/metabolismo , Glucólisis
16.
J Biomech Eng ; 133(11): 111002, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22168734

RESUMEN

This study investigates the effect of the pilot hole size, implant depth, synthetic bone density, and screw size on the pullout strength of the self-tapping screw using analytical, finite element, and experimental methodologies. Stress distribution and failure propagation mode around the implant thread zone are also investigated. Based on the finite element analysis (FEA) results, an analytical model for the pullout strength of the self-tapping screw is constructed in terms of the (synthetic) bone mechanical properties, screw size, and the implant depth. The pullout performance of self-tapping screws is discussed. Results from the analytical and finite element models are experimentally validated.


Asunto(s)
Tornillos Óseos , Fenómenos Biomecánicos , Sustitutos de Huesos , Fuerza Compresiva , Análisis de Elementos Finitos , Humanos , Ensayo de Materiales , Modelos Biológicos , Resistencia a la Tracción
17.
Stem Cell Res ; 56: 102516, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34469777

RESUMEN

The homozygous autosomal recessive truncating mutations of LDL receptor related protein associated protein 1 (LRPAP1) is a possible reason for Nonsyndromic Extreme Myopia, patients with which show typical chorioretinal degeneration. We generated an LRPAP1 knockout FDCHDPe009-B embryonic stem cell line to study mechanisms of retinal degeneration underlying LRPAP1 deficiency with the help of the CRISPR/Cas9 system. Two distinct biallelic deletions in the cell line have been confirmed, which causing a frameshift and premature stop codons thus influence the translation of LRPAP1. FDCHDPe009-B has maintained normal stem cell morphology, pluripotent gene expression, parental karyotype, and ability to differentiate into three germ layers.


Asunto(s)
Sistemas CRISPR-Cas , Células Madre Embrionarias Humanas , Sistemas CRISPR-Cas/genética , Línea Celular , Células Madre Embrionarias , Humanos , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad
18.
Stem Cell Res ; 53: 102342, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33878707

RESUMEN

LRP2 is mainly expressed in the cell membrane of epithelia, maintaining normal endocytosis of nutrients from the extracellular microenvironment and mediating growth factor signals. The deficiency of LRP2 can result in abnormal lysosomal and mitochondrial function as well as insufficient resistance to oxidative stress. LRP2-KO animals show enlarged eyes and malfunction of the retinal pigment epithelium (RPE). We were able to generate an LRP2-KO human embryonic stem (ES) cell line using CRISPR/Cas9 gene editing and differentiate the mutant ES cells into RPE cells. Thus, this LRP2-KO human ES line will facilitate studying cellular mechanisms of eye disease due to LRP2 deficiency.


Asunto(s)
Sistemas CRISPR-Cas , Células Madre Embrionarias Humanas , Animales , Sistemas CRISPR-Cas/genética , Línea Celular , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Células Madre Embrionarias/metabolismo , Células Madre Embrionarias Humanas/metabolismo , Humanos , Proteína 2 Relacionada con Receptor de Lipoproteína de Baja Densidad/genética , Proteína 2 Relacionada con Receptor de Lipoproteína de Baja Densidad/metabolismo
19.
Front Cell Dev Biol ; 9: 653305, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34055784

RESUMEN

The developing retina expresses multiple bHLH transcription factors. Their precise functions and interactions in uncommitted retinal progenitors remain to be fully elucidated. Here, we investigate the roles of bHLH factors ATOH7 and Neurog2 in human ES cell-derived retinal organoids. Single cell transcriptome analyses identify three states of proliferating retinal progenitors: pre-neurogenic, neurogenic, and cell cycle-exiting progenitors. Each shows different expression profile of bHLH factors. The cell cycle-exiting progenitors feed into a postmitotic heterozygous neuroblast pool that gives rise to early born neuronal lineages. Elevating ATOH7 or Neurog2 expression accelerates the transition from the pre-neurogenic to the neurogenic state, and expands the exiting progenitor and neuroblast populations. In addition, ATOH7 and Neurog2 significantly, yet differentially, enhance retinal ganglion cell and cone photoreceptor production. Moreover, single cell transcriptome analyses reveal that ATOH7 and Neurog2 each assert positive autoregulation, and both suppress key bHLH factors associated with the pre-neurogenic and states and elevate bHLH factors expressed by exiting progenitors and differentiating neuroblasts. This study thus provides novel insight regarding how ATOH7 and Neurog2 impact human retinal progenitor behaviors and neuroblast fate choices.

20.
J Neurosci ; 29(21): 6932-44, 2009 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-19474320

RESUMEN

Cell-extrinsic signals can profoundly influence the production of various neurons from common progenitors. Yet mechanisms by which extrinsic signals coordinate progenitor cell proliferation, cell cycle exit, and cell fate choices are not well understood. Here, we address whether Hedgehog (Hh) signals independently regulate progenitor proliferation and neuronal fate decisions in the embryonic mouse retina. Conditional ablation of the essential Hh signaling component Smoothened (Smo) in proliferating progenitors, rather than in nascent postmitotic neurons, leads to a dramatic increase of retinal ganglion cells (RGCs) and a mild increase of cone photoreceptor precursors without significantly affecting other early-born neuronal cell types. In addition, Smo-deficient progenitors exhibit aberrant expression of cell cycle regulators and delayed G(1)/S transition, especially during the late embryonic stages, resulting in a reduced progenitor pool by birth. Deficiency in Smo function also causes reduced expression of the basic helix-loop-helix transcription repressor Hes1 and preferential elevation of the proneural gene Math5. In Smo and Math5 double knock-out mutants, the enhanced RGC production observed in Smo-deficient retinas is abolished, whereas defects in the G(1)/S transition persist, suggesting that Math5 mediates the Hh effect on neuronal fate specification but not on cell proliferation. These findings demonstrate that Hh signals regulate progenitor pool expansion primarily by promoting cell cycle progression and influence cell cycle exit and neuronal fates by controlling specific proneural genes. Together, these distinct cellular effects of Hh signaling in neural progenitor cells coordinate a balanced production of diverse neuronal cell types.


Asunto(s)
Ciclo Celular/fisiología , Diferenciación Celular/fisiología , Proteínas Hedgehog/metabolismo , Neuronas/fisiología , Retina/citología , Transducción de Señal/fisiología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Ciclo Celular/genética , Diferenciación Celular/genética , Proliferación Celular , Embrión de Mamíferos , Células Madre Embrionarias/fisiología , Femenino , Citometría de Flujo/métodos , Regulación del Desarrollo de la Expresión Génica , Proteínas Fluorescentes Verdes/genética , Proteínas Hedgehog/genética , Proteínas de Homeodominio/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteínas del Tejido Nervioso/genética , Neuronas/clasificación , Receptores Acoplados a Proteínas G/deficiencia , Retina/embriología , Células Fotorreceptoras Retinianas Conos/fisiología , Células Ganglionares de la Retina/fisiología , Transducción de Señal/genética , Receptor Smoothened , Técnicas de Cultivo de Tejidos , Factores de Transcripción/genética
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