RESUMEN
Primordial germ cells (PGCs) are the precursors of gametes and the sole mechanism by which animals transmit genetic information across generations. In the mouse embryo, the transcriptional and epigenetic regulation of PGC specification has been extensively characterized. However, the initial event that triggers the soma-germline segregation remains poorly understood. Here, we uncover a critical role for the basement membrane in regulating germline entry. We show that PGCs arise in a region of the mouse embryo that lacks contact with the basement membrane, and the addition of exogenous extracellular matrix (ECM) inhibits both PGC and PGC-like cell (PGCLC) specification in mouse embryos and stem cell models, respectively. Mechanistically, we demonstrate that the engagement of ß1 integrin with laminin blocks PGCLC specification by preventing the Wnt signaling-dependent down-regulation of the PGC transcriptional repressor, Otx2. In this way, the physical segregation of cells away from the basement membrane acts as a morphogenetic fate switch that controls the soma-germline bifurcation.
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Células Germinativas , Células Madre Pluripotentes , Animales , Ratones , Células Germinativas/metabolismo , Células Germinativas/citología , Células Madre Pluripotentes/metabolismo , Células Madre Pluripotentes/citología , Transducción de Señal , Integrinas/metabolismo , Integrinas/genética , Membrana Basal/metabolismo , Vía de Señalización Wnt , Diferenciación Celular , Matriz Extracelular/metabolismo , Laminina/metabolismo , Regulación del Desarrollo de la Expresión Génica , Integrina beta1/metabolismo , Integrina beta1/genética , Factores de Transcripción Otx/metabolismo , Factores de Transcripción Otx/genética , Embrión de Mamíferos/metabolismo , Embrión de Mamíferos/citologíaRESUMEN
During the epithelial-mesenchymal transition driving mouse embryo gastrulation, cells divide more frequently at the primitive streak, and half of those divisions happen away from the apical pole. These observations suggest that non-apical mitoses might play a role in cell delamination. We aim to uncover and challenge the molecular determinants of mitosis position in different regions of the epiblast through computational modeling and pharmacological treatments of embryos and stem cell-based epiblast spheroids. Blocking basement membrane degradation at the streak has no impact on the asymmetry in mitosis frequency and position. By contrast, disturbance of the actomyosin cytoskeleton or cell cycle dynamics elicits ectopic non-apical mitosis and shows that the streak region is characterized by local relaxation of the actomyosin cytoskeleton and less stringent regulation of cell division. These factors are essential for normal dynamics at the streak and favor cell delamination from the epiblast.
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Actomiosina , Gastrulación , Estratos Germinativos , Mitosis , Animales , Ratones , Estratos Germinativos/citología , Estratos Germinativos/metabolismo , Actomiosina/metabolismo , Transición Epitelial-Mesenquimal , Embrión de Mamíferos/citología , Línea Primitiva/citología , Línea Primitiva/metabolismo , Femenino , Membrana Basal/metabolismo , Citoesqueleto/metabolismo , Ciclo CelularRESUMEN
PURPOSE: To compare the pathological characteristics of the vitreomacular interface of the idiopathic epiretinal membrane with and without disorganization of retinal inner layers (DRIL) and to correlate with clinical data. METHODS: In this clinicopathologic study, the samples of epiretinal membrane and internal limiting membrane were extracted from DRIL(+) (19 eyes) and DRIL(-) (22 eyes) idiopathic epiretinal membrane eyes. Ultrathin series sectioning for transmission electron microscopy was observed and correlated with surgery status and prognosis. RESULTS: All idiopathic epiretinal membrane eyes presented fibrocellular membranes accompanied by vitreous collagen, glial cells, and myofibroblasts, regardless of association with DRIL. A robust signal indicative of Collagen Type VI was observed in eyes DRIL(-), whereas Collagen Type I was discovered in DRIL eyes. Cell debris and microvascular basement membrane were seen on the retinal side of DRIL eyes and a larger cell count on the vitreous side. These have more intraoperative complications and less surgery benefit. CONCLUSION: Although internal limiting membrane peeling seems important, the histopathologic findings underscore the potential for retinal injury in DRIL(+) idiopathic epiretinal membrane eyes. This suggests that further research is needed to investigate individual preoperative assessment and to modify surgical procedures.
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Membrana Epirretinal , Vitrectomía , Cuerpo Vítreo , Humanos , Membrana Epirretinal/cirugía , Membrana Epirretinal/metabolismo , Membrana Epirretinal/diagnóstico , Membrana Epirretinal/patología , Anciano , Masculino , Femenino , Cuerpo Vítreo/patología , Cuerpo Vítreo/metabolismo , Persona de Mediana Edad , Microscopía Electrónica de Transmisión , Membrana Basal/patología , Membrana Basal/cirugía , Membrana Basal/metabolismo , Anciano de 80 o más Años , Tomografía de Coherencia Óptica/métodos , Agudeza Visual , Mácula Lútea/patología , Retina/patologíaRESUMEN
PURPOSE: To investigate changes to the vitreoretinal interface in uveitis with multimodal imaging including adaptive optics. METHODS: Four eyes (four patients) affected by fovea-attached (subtype 1A) or fovea-sparing epiretinal membranes (ERMs) on spectral-domain optical coherence tomography or visible internal limiting membrane (ILM) on infrared scanning laser ophthalmoscope (SLO) fundus imaging were recruited in this pilot study. The microstructure of the vitreoretinal interface was imaged using flood-illumination adaptive optics (FIAO), and the images were compared with the cross-sectional spectral-domain optical coherence tomography data. RESULTS: Adaptive optics images revealed multiple abnormalities of the vitreoretinal interface, such as deep linear striae in ERM, and hyperreflective microstructures at the location of ERMs and ILMs. The cone mosaic was imaged by FIAO and was found altered in the four eyes with ERMs or visible ILM. The same four eyes presented alteration of photopic 30 Hz flicker that was reduced in amplitude indicating cone inner retinal layer dysfunction. CONCLUSION: FIAO imaging can identify specific patterns associated with ERMs and ILMs. Correlating FIAO imaging of the vitreomacular interface with the structural alterations seen in FIAO at the level of the outer retinal structures can help understand the cause of significant macular dysfunction associated with ERM.
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Membrana Epirretinal , Imagen Multimodal , Tomografía de Coherencia Óptica , Humanos , Tomografía de Coherencia Óptica/métodos , Masculino , Femenino , Persona de Mediana Edad , Membrana Epirretinal/diagnóstico , Proyectos Piloto , Oftalmoscopía/métodos , Cuerpo Vítreo/patología , Cuerpo Vítreo/diagnóstico por imagen , Uveítis/diagnóstico , Adulto , Agudeza Visual , Anciano , Estudios Transversales , Membrana BasalRESUMEN
Colorectal cancer (COCA) has a poor prognosis, with growing evidence implicating basement membranes (BMs) in cancer progression. Our goal was to investigate the role and predictive significance of BMs in COCA patients. We obtained BMs-related genes from cutting-edge research and used TCGA and GTEx databases for mRNA expression and patient information. Cox regression and LASSO regression were used for prognostic gene selection and risk model construction. We compared prognosis using Kaplan-Meier analysis and examined drug sensitivity differences. The CMAP dataset identified potential small molecule drugs. In vitro tests involved suppressing a crucial gene to observe its impact on tumour metastasis. We developed a 12 BMs-based approach, finding it to be an independent prognostic factor. Functional analysis showed BMs concentrated in cancer-associated pathways, correlating with immune cell infiltration and immune checkpoint activation. High-risk individuals exhibited increased drug sensitivity. AGRN levels were linked to decreased progression-free survival (p < 0.001). AGRN knockdown suppressed tumour growth and metastasis. Our study offers new perspectives on BMs in COCA, concluding that AGRN is a dependable biomarker for patient survival and prognosis.
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Membrana Basal , Biomarcadores de Tumor , Neoplasias Colorrectales , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Membrana Basal/metabolismo , Membrana Basal/patología , Biomarcadores de Tumor/genética , Pronóstico , Femenino , Estimación de Kaplan-Meier , Masculino , Línea Celular Tumoral , Animales , RatonesRESUMEN
BACKGROUND: The prognosis of patients with metastatic osteosarcoma is poor, and the variation of basement membrane genes (BMGs) is associated with cancer metastasis. However, the role of BMGs in osteosarcoma has been poorly studied. METHODS: BMGs were collected and differentially expressed BMGs (DE-BMGs) were found through difference analysis. DE-BMGs were further screened by univariate Cox regression and Lasso regression analyses, and six key BMGs were identified and defined as basement membrane genes signatures (BMGS). Then, BMGS was used to construct the osteosarcoma BMGS risk score system, and the osteosarcoma patients were divided into high- and low-risk groups based on the median risk score. Single-sample gene set enrichment analysis (ssGSEA) and ESTIMATE scores were used to investigate the differences in immune infiltration between the two scoring groups. Additionally, we investigated whether UNC5B affects various features in tumors by bioinformatic analysis and whether UNC5B was involved in multiple biological functions of osteosarcoma cells by wound healing assay, transwell assay, and western blot. RESULTS: The osteosarcoma BMGS risk score reliably predicts the risk of metastasis, patient prognosis, and immunity. UNC5B expression was elevated in osteosarcoma, and correlated with various characteristics such as immune infiltration, prognosis, and drug sensitivity. In vitro assays showed that UNC5B knockdown reduced osteosarcoma cells' capacity for migration and invasion, and EMT process. CONCLUSION: A novel BMGS risk score system that can effectively predict the prognosis of osteosarcoma was developed and validated. The UNC5B gene in this system is one of the key aggressive biomarkers of osteosarcoma.
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Membrana Basal , Biomarcadores de Tumor , Neoplasias Óseas , Regulación Neoplásica de la Expresión Génica , Receptores de Netrina , Osteosarcoma , Osteosarcoma/genética , Osteosarcoma/patología , Humanos , Biomarcadores de Tumor/genética , Neoplasias Óseas/genética , Neoplasias Óseas/patología , Pronóstico , Membrana Basal/metabolismo , Membrana Basal/patología , Línea Celular Tumoral , Receptores de Netrina/genética , Receptores de Netrina/metabolismo , Masculino , Femenino , Movimiento Celular/genéticaRESUMEN
Human primary lens epithelial cultures serve as an in vitro model for posterior capsular opacification (PCO) formation. PCO occurs when residual lens epithelial cells (LECs) migrate and proliferate after cataract surgery, differentiating into fibroblastic and lens fiber-like cells. This study aims to show and compare the bio-macromolecular profiles of primary LEC cultures and postoperative lens epithelia LECs on basal laminas (bls), while also analyzing bls and cultured LECs separately. Using synchrotron radiation-based Fourier transform infrared (SR-FTIR) (Bruker, Karlsruhe, Germany) microspectroscopy at the Spanish synchrotron light source ALBA, we observed that the SR-FTIR measurements were predominantly influenced by the strong collagen absorbance of the bls. Cultured LECs on bls showed a higher collagen contribution, indicated by higher vas CH3, CH2 and CH3 wagging and deformation, and the C-N stretching of collagen. In contrast, postoperative LECs on bls showed a higher cell contribution, indicated by the vsym CH2 peak and the ratio between vas CH2 and vas CH3 peaks. The primary difference revealed using SR-FTIR is the greater LEC contribution in spectra recorded from postoperative lens epithelia compared to cultured LECs on bls. IR spectra for bl, cultured LECs and postoperative lens epithelia could be valuable for future research.
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Células Epiteliales , Cristalino , Sincrotrones , Humanos , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Células Epiteliales/metabolismo , Células Epiteliales/patología , Células Cultivadas , Cristalino/metabolismo , Cristalino/citología , Opacificación Capsular/metabolismo , Opacificación Capsular/patología , Membrana Basal/metabolismo , Colágeno/metabolismo , Anciano , Persona de Mediana EdadRESUMEN
Heparan sulfate (HS) regulation of FGFR function, which is essential for salivary gland (SG) development, is determined by the immense structural diversity of sulfated HS domains. 3-O-sulfotransferases generate highly 3-O-sulfated HS domains (3-O-HS), and Hs3st3a1 and Hs3st3b1 are enriched in myoepithelial cells (MECs) that produce basement membrane (BM) and are a growth factor signaling hub. Hs3st3a1;Hs3st3b1 double-knockout (DKO) mice generated to investigate 3-O-HS regulation of MEC function and growth factor signaling show loss of specific highly 3-O-HS and increased FGF/FGFR complex binding to HS. During development, this increases FGFR-, BM- and MEC-related gene expression, while in adult, it reduces MECs, increases BM and disrupts acinar polarity, resulting in salivary hypofunction. Defined 3-O-HS added to FGFR pulldown assays and primary organ cultures modulates FGFR signaling to regulate MEC BM synthesis, which is critical for secretory unit homeostasis and acinar function. Understanding how sulfated HS regulates development will inform the use of HS mimetics in organ regeneration.
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Membrana Basal , Diferenciación Celular , Células Epiteliales , Heparitina Sulfato , Ratones Noqueados , Glándulas Salivales , Transducción de Señal , Sulfotransferasas , Animales , Heparitina Sulfato/metabolismo , Membrana Basal/metabolismo , Glándulas Salivales/metabolismo , Glándulas Salivales/citología , Sulfotransferasas/metabolismo , Sulfotransferasas/genética , Ratones , Células Epiteliales/metabolismo , Células Epiteliales/citología , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Receptores de Factores de Crecimiento de Fibroblastos/genética , Masculino , Factores de Crecimiento de Fibroblastos/metabolismoRESUMEN
Bladder cancer (BC) is fatal during muscle invasion and treatment progress is limited. In this study, we aimed to construct and validate basement membrane (BM)-associated gene prognosis to predict BC progression and tumor immune infiltration correlation. We choreographed BM-related genes in the Cancer Genome Atlas (TCGA) database using COX regression and least absolute shrinkage and selection operator (LASSO) analysis, and the predictive value of BM-related genes was further validated by the GSE32548, GSE129845, and immunohistochemistry staining. All analyses were performed with R-version 4.2.2, and its appropriate packages. Three genes were identified to construct a gene signature to predictive of BC prognosis. We divided the TCGA database into 2 groups, and patients in the high-risk group had worse overall survival (OS) than those in the low-risk group. In GSE32548, we confirmed that patients in the high-risk group had a poorer prognosis compared to those in the low-risk group in terms of OS. Immunohistochemical staining of EPEMP1, GPC2, and ITGA3 showed significantly higher expression at the protein level in BC tissues than in normal tissues. The Spearman analysis showed risk score was positively correlated with B cell naïve, Macrophages M2, and Mast cells resting. stromal score, immune score, and ESTIMATE scores were significantly higher in the high-risk group. drugs sensitivity analysis showed IC50 of Cisplatin, Gemcitabine, and Methotrexate in the high-risk group was significantly higher than that in the low-risk group. We identified 3 prognostic genes from a novel perspective of BM genes as effective risk stratification tools for BC patients.
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Membrana Basal , Neoplasias de la Vejiga Urinaria , Humanos , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/inmunología , Neoplasias de la Vejiga Urinaria/mortalidad , Neoplasias de la Vejiga Urinaria/patología , Pronóstico , Membrana Basal/inmunología , Membrana Basal/patología , Masculino , Femenino , Biomarcadores de Tumor/genética , Persona de Mediana Edad , Anciano , Regulación Neoplásica de la Expresión GénicaRESUMEN
The spleen is an immune organ that plays a key role in blood-borne immune responses. The anatomical or functional loss of this tissue increases susceptibility to severe blood infections and sepsis. Auto-transplantation of spleen slices has been used clinically to replace lost tissue and restore immune function. However, the mechanism driving robust and immunologically functional spleen tissue regeneration has not been fully elucidated. Here, we aim to develop a method for aggregating and encapsulating spleen cells within a semi-solid matrix in order to investigate the cellular requirements for spleen tissue formation. Basement membrane matrix encapsulated cell constructs are amenable to both in vitro tissue culture of three-dimensional organoids as well as transplantation under the kidney capsule to directly assess in vivo tissue formation. By manipulating the input cells for aggregation and encapsulation, we demonstrate that graft-derived PDGFRß+MAdCAM-1- neonatal stromal cells are required for spleen tissue regeneration under animal transplantation models.
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Membrana Basal , Bazo , Animales , Ratones , Bazo/citología , Membrana Basal/citología , Agregación Celular/fisiologíaRESUMEN
OBJECTIVE: This study aimed to evaluate and explore the efficacy of pars plana vitrectomy (PPV) combined with internal limiting membrane (ILM) peeling and gas tamponade in treating myopic foveoschisis (MF) through a meta-analysis. METHODS: Systematic searches were conducted on the PubMed, Web of Science and National Library of Medicine (NLM) English-language databases and the China National Knowledge Infrastructure (CNKI) and Wanfang Chinese-language databases. The primary outcome measures were postoperative best-corrected visual acuity (BCVA) and central foveal thickness (CFT), with the secondary outcome being the postoperative complication rate. Data analysis was performed using RevMan5.3 software. RESULTS: A total of 10 studies involving 234 eyes were included. The meta-analysis results showed the following: (1) The average postoperative BCVA improved compared with preoperative levels, with an average improvement in the logarithm of the minimum angle of resolution of 0.40, a statistically significant difference (95% CI: -0.44, - 0.20, p < 0.001); (2) the rate of postoperative BCVA improvement was 77% (95% CI: 65%, 90%, p < 0.001); (3) the postoperative CFT significantly decreased by an average of 385.92 µm, a statistically significant difference (95% CI: -437.85, - 333.98, p < 0.001); (4) the postoperative macular retinal complete reattachment rate was 90% (95% CI: 83%, 97%, p < 0.001); (5) the most common postoperative complication was a cataract, with an incidence of 55.9%. CONCLUSION: Using PPV combined with ILM peeling and gas tamponade to treat MF is reliable.
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Membrana Basal , Endotaponamiento , Retinosquisis , Agudeza Visual , Vitrectomía , Humanos , Vitrectomía/métodos , Retinosquisis/cirugía , Endotaponamiento/métodos , Agudeza Visual/fisiología , Membrana Basal/cirugía , Miopía Degenerativa/cirugía , Miopía Degenerativa/complicaciones , Miopía Degenerativa/fisiopatología , Miopía/cirugía , Miopía/fisiopatologíaRESUMEN
Decreased myocardial capillary density has been reported as an important histopathological feature associated with various heart disorders. Quantitative assessment of cardiac capillarization typically involves double immunostaining of cardiomyocytes (CMs) and capillaries in myocardial slices. In contrast, single immunostaining of basement membrane protein is a straightforward approach to simultaneously label CMs and capillaries, presenting fewer challenges in background staining. However, subsequent image analysis always requires expertise and laborious manual work to identify and segment CMs/capillaries. Here, we developed an image analysis tool, AutoQC, for automatic identification and segmentation of CMs and capillaries in immunofluorescence images of basement membrane. Commonly used capillarization-related measurements can be derived from segmentation results. By leveraging the power of a pre-trained segmentation model (Segment Anything Model, SAM) via prompt engineering, the training of AutoQC required only a small dataset with bounding box annotations instead of pixel-wise annotations. AutoQC outperformed SAM (without prompt engineering) and YOLOv8-Seg, a state-of-the-art instance segmentation model, in both instance segmentation and capillarization assessment. Thus, AutoQC, featuring a weakly supervised algorithm, enables automatic segmentation and high-throughput, high-accuracy capillarization assessment in basement-membrane-immunostained myocardial slices. This approach reduces the training workload and eliminates the need for manual image analysis once AutoQC is trained.
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Membrana Basal , Procesamiento de Imagen Asistido por Computador , Miocardio , Miocitos Cardíacos , Membrana Basal/metabolismo , Animales , Miocitos Cardíacos/metabolismo , Miocardio/metabolismo , Miocardio/patología , Procesamiento de Imagen Asistido por Computador/métodos , Capilares/metabolismo , Algoritmos , Ratones , Vasos Coronarios/metabolismo , Vasos Coronarios/patologíaRESUMEN
BACKGROUND: To compare the surgical outcomes of the inverted internal limiting membrane (ILM) flap technique and ILM insertion for macular hole (MH) without retinal detachment in eyes with extremely high myopia. METHODS: In this retrospective study, we analyzed 22 eyes with an axial length ≥ 30.0 mm that had underwent MH surgery between April 2015 and August 2021. The surgical procedures involved either an inverted ILM flap or ILM insertion. The outcomes were compared between the two techniques. Closure of the MH was confirmed by optical coherence tomography (OCT). The best-corrected visual acuity (BCVA) was measured before and after surgery. Associated complications were documented. RESULTS: The median of axial length was 30.64 mm (range, 30.0-34.42). The MH closed in 100% (22/22) eyes and did not recur with a median follow-up of 12.5 months. For the inverted ILM flap technique, the median BCVA improved significantly from 0.80 logarithm of the minimum angle of resolution (logMAR) (range, 0.40-2.00) before surgery to 0.70 logMAR (range, 0.09-1.52) after surgery (p = 0.002). In addition, the median of final BCVA was better for the inverted ILM flap than ILM insertion (0.7 logMAR V.S. 1.00 logMAR; p = 0.016). CONCLUSIONS: In eyes with extremely high myopia, despite comparable effects on MH closure for both ILM insertion and the inverted ILM flap, the later technique achieved significantly better visual outcomes.
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Membrana Basal , Miopía Degenerativa , Perforaciones de la Retina , Colgajos Quirúrgicos , Tomografía de Coherencia Óptica , Agudeza Visual , Vitrectomía , Humanos , Perforaciones de la Retina/cirugía , Estudios Retrospectivos , Masculino , Femenino , Agudeza Visual/fisiología , Persona de Mediana Edad , Tomografía de Coherencia Óptica/métodos , Vitrectomía/métodos , Membrana Basal/cirugía , Miopía Degenerativa/cirugía , Miopía Degenerativa/complicaciones , Miopía Degenerativa/fisiopatología , Anciano , Adulto , Estudios de SeguimientoRESUMEN
PURPOSE: To evaluate anatomic outcomes and surgeon response following the use of microserrated (Sharkskin, Alcon, Forth Worth, TX) internal limiting membrane (ILM) forceps compared with conventional (Grieshaber; Alcon) ILM forceps for peeling of the ILM. METHODS: Patients were prospectively assigned in a 1:1 randomized fashion to undergo ILM peeling using microserrated forceps or conventional forceps. Rates of retinal hemorrhages, deep retinal grasps, ILM regrasping, time to ILM removal, and surgeon questionnaire comparing the use of microserrated and conventional ILM forceps were analyzed. RESULTS: A total of 90 eyes of 90 patients were included in this study. The mean number of deep retinal grasps was higher in the conventional forceps group (1.51 ± 1.70 vs. 0.33 ± 0.56, respectively [P < 0.0001]). The mean number of failed ILM grasps was higher with conventional forceps (6.62 ± 3.51 vs. 5.18 ± 2.06 [P = 0.019]). Microserrated forceps provided more comfortability (lower number) in initiating the ILM flap (2.16 ± 0.85 vs. 1.56 ± 0.76, P < 0.001), comfortability in regrasping the ILM flap (2.51 ± 1.01 vs. 1.98 ± 0.89, P = 0.01), and comfortability in completing the ILM flap (2.42 ± 1.03 vs. 1.84 ± 1.02, P = 0.01). CONCLUSION: Surgeons utilizing the microserrated forceps experienced fewer deep retina grasps and fewer failed ILM grasps compared with conventional ILM forceps. The microserrated forceps was also a more favorable experience subjectively among the surgeons.
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Membrana Basal , Agudeza Visual , Vitrectomía , Humanos , Femenino , Masculino , Estudios Prospectivos , Membrana Basal/cirugía , Vitrectomía/instrumentación , Vitrectomía/métodos , Anciano , Persona de Mediana Edad , Instrumentos Quirúrgicos , Membrana Epirretinal/cirugía , Tomografía de Coherencia Óptica , Diseño de Equipo , Estudios de Seguimiento , Colgajos QuirúrgicosRESUMEN
Purpose: The purpose of this study was to investigate the ocular morphological characteristics of Col4a3-/- mice as a model of Alport syndrome (AS) and the potential pathogenesis. Methods: The expression of collagen IV at 8, 12, and 21 weeks of age was evaluated by immunohistochemistry in wild-type (WT) and Col4a3-/- mice. Hematoxylin and eosin (H&E) staining and thickness measurements were performed to assess the thickness of anterior lens capsule and retina. Ultrastructure analysis of corneal epithelial basement membrane, anterior lens capsule, internal limiting membrane (ILM), and retinal pigment epithelium (RPE) basement membrane was performed using transmission electron microscopy. Finally, Müller cell activation was evaluated by glial fibrillary acidic protein (GFAP) expression. Results: Collagen IV was downregulated in the corneal epithelial basement membrane and ILM of Col4a3-/- mice. The hemidesmosomes of Col4a3-/- mice corneal epithelium became flat and less electron-dense than those of the WT group. Compared with those of the WT mice, the anterior lens capsules of Col4a3-/- mice were thinner. Abnormal structure was detected at the ILM Col4a3-/- mice, and the basal folds of the RPE basement membrane in Col4a3-/- mice were thicker and shorter. The retinas of Col4a3-/- mice were thinner than those of WT mice, especially within 1000 µm away from the optic nerve. GFAP expression enhanced in each age group of Col4a3-/- mice. Conclusions: Our results suggested that Col4a3-/- mice exhibit ocular anomalies similar to patients with AS. Additionally, Müller cells may be involved in AS retinal anomalies. Translational Relevance: This animal model could provide an opportunity to understand the underlying mechanisms of AS ocular disorders and to investigate potential new treatments.
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Membrana Basal , Colágeno Tipo IV , Modelos Animales de Enfermedad , Ratones Noqueados , Nefritis Hereditaria , Animales , Nefritis Hereditaria/patología , Nefritis Hereditaria/genética , Nefritis Hereditaria/metabolismo , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Colágeno Tipo IV/deficiencia , Ratones , Membrana Basal/metabolismo , Membrana Basal/patología , Membrana Basal/ultraestructura , Epitelio Pigmentado de la Retina/patología , Epitelio Pigmentado de la Retina/metabolismo , Epitelio Pigmentado de la Retina/ultraestructura , Microscopía Electrónica de Transmisión , Ratones Endogámicos C57BL , Cápsula del Cristalino/metabolismo , Cápsula del Cristalino/patología , Cápsula del Cristalino/ultraestructura , Epitelio Corneal/patología , Epitelio Corneal/ultraestructura , Epitelio Corneal/metabolismo , Proteína Ácida Fibrilar de la Glía/metabolismo , Proteína Ácida Fibrilar de la Glía/genética , Retina/patología , Retina/metabolismo , Retina/ultraestructura , Autoantígenos/genética , Autoantígenos/metabolismo , Células Ependimogliales/patología , Células Ependimogliales/metabolismo , Células Ependimogliales/ultraestructura , Inmunohistoquímica , MasculinoRESUMEN
The sense of touch is conferred by the conjoint function of somatosensory neurons and skin cells. These cells meet across a gap filled by a basal lamina, an ancient structure found in metazoans. Using Caenorhabditis elegans, we investigate the composition and ultrastructure of the extracellular matrix at the epidermis and touch receptor neuron (TRN) interface. We show that membrane-matrix complexes containing laminin, nidogen, and the MEC-4 mechano-electrical transduction channel reside at this interface and are central to proper touch sensation. Interestingly, the dimensions and spacing of these complexes correspond with the discontinuous beam-like extracellular matrix structures observed in serial-section transmission electron micrographs. These complexes fail to coalesce in touch-insensitive extracellular matrix mutants and in dissociated neurons. Loss of nidogen reduces the density of mechanoreceptor complexes and the amplitude of the touch-evoked currents they carry. Thus, neuron-epithelium cell interfaces are instrumental in mechanosensory complex assembly and function. Unlike the basal lamina ensheathing the pharynx and body wall muscle, nidogen recruitment to the puncta along TRNs is not dependent upon laminin binding. MEC-4, but not laminin or nidogen, is destabilized by point mutations in the C-terminal Kunitz domain of the extracellular matrix component, MEC-1. These findings imply that somatosensory neurons secrete proteins that actively repurpose the basal lamina to generate special-purpose mechanosensory complexes responsible for vibrotactile sensing.
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Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Mecanorreceptores , Mecanotransducción Celular , Animales , Caenorhabditis elegans/fisiología , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Mecanorreceptores/metabolismo , Mecanorreceptores/fisiología , Mecanotransducción Celular/fisiología , Tacto/fisiología , Membrana Basal/metabolismo , Membrana Basal/fisiología , Matriz Extracelular/metabolismo , Laminina/metabolismo , Glicoproteínas de Membrana , Proteínas de la MembranaRESUMEN
To breach the basement membrane, cells in development and cancer use large, transient, specialized lipid-rich membrane protrusions. Using live imaging, endogenous protein tagging, and cell-specific RNAi during Caenorhabditis elegans anchor cell (AC) invasion, we demonstrate that the lipogenic SREBP transcription factor SBP-1 drives the expression of the fatty acid synthesis enzymes POD-2 and FASN-1 prior to invasion. We show that phospholipid-producing LPIN-1 and sphingomyelin synthase SMS-1, which use fatty acids as substrates, produce lysosome stores that build the AC's invasive protrusion, and that SMS-1 also promotes protrusion localization of the lipid raft partitioning ZMP-1 matrix metalloproteinase. Finally, we discover that HMG-CoA reductase HMGR-1, which generates isoprenoids for prenylation, localizes to the ER and enriches in peroxisomes at the AC invasive front, and that the final transmembrane prenylation enzyme, ICMT-1, localizes to endoplasmic reticulum exit sites that dynamically polarize to deliver prenylated GTPases for protrusion formation. Together, these results reveal a collaboration between lipogenesis and a polarized lipid prenylation system that drives invasive protrusion formation.
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Membrana Basal , Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Retículo Endoplásmico , Lipogénesis , Animales , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Membrana Basal/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Retículo Endoplásmico/metabolismo , Lipogénesis/genética , Prenilación , Peroxisomas/metabolismo , Movimiento Celular , Lisosomas/metabolismoRESUMEN
The ADAMTS (a disintegrin and metalloprotease with thrombospondin motifs) family metalloprotease MIG-17 plays a crucial role in the migration of gonadal distal tip cells (DTCs) in Caenorhabditis elegans. MIG-17 is secreted from the body wall muscle cells and localizes to the basement membranes (BMs) of various tissues including the gonadal BM where it regulates DTC migration through its catalytic activity. Missense mutations in the BM protein genes, let-2/collagen IV a2 and fbl-1/fibulin-1, have been identified as suppressors of the gonadal defects observed in mig-17 mutants. Genetic analyses indicate that LET-2 and FBL-1 act downstream of MIG-17 to regulate DTC migration. In addition to the control of DTC migration, MIG-17 also plays a role in healthspan, but not in lifespan. Here, we examined whether let-2 and fbl-1 alleles can suppress the age-related phenotypes of mig-17 mutants. let-2(k196) fully and fbl-1(k201) partly, but not let-2(k193) and fbl-1(k206), suppressed the senescence defects of mig-17. Interestingly, fbl-1(k206), but not fbl-1(k201) or let-2 alleles, exhibited an extended lifespan compared to the wild type when combined with mig-17. These results reveal allele specific interactions between let-2 or fbl-1 and mig-17 in age-related phenotypes, indicating that basement membrane physiology plays an important role in organismal aging.
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Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Colágeno Tipo IV , Mutación , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Colágeno Tipo IV/metabolismo , Colágeno Tipo IV/genética , Longevidad/genética , Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/metabolismo , Membrana Basal/metabolismo , Fenotipo , Movimiento Celular/genética , Gónadas/metabolismo , Metaloendopeptidasas/genética , Metaloendopeptidasas/metabolismo , DesintegrinasRESUMEN
PURPOSE: To compare anatomical and functional outcomes of four different techniques for the treatment of large idiopathic full-thickness macular holes. METHODS: This single-center retrospective study included 129 eyes of 126 patients with large (>500 µ m) full-thickness macular holes who presented between January 2018 and October 2022. All patients underwent 23/25 G vitrectomy and gas with standard internal limiting membrane (ILM) peel, pedicle transposition, inverted, or free flap technique. Postoperative optical coherence tomography images were assessed by two independent masked graders. RESULTS: Mean age was 73.2 years (SD 8.4) with a median F/U of 5 months (IQR 8). The overall anatomical success rate was 81%; it was significantly lower (59%) for the standard ILM peel ( P < 0.0001). The pedicle transposition flap showed superior visual recovery compared with the free flap (+27 vs. +12 ETDRS letters, P = 0.02). At 3 months, restoration of the external limiting membrane was significantly better for the pedicle transposition flap compared with free flap and standard ILM peel ( P = 0.008 and P = 0.03) and superior to all the other techniques at 6 months ( P = 0.02, P = 0.04, and P = 0.006). CONCLUSION: Standard ILM peel alone offers inferior outcomes for the management of large full-thickness macular holes. Of the alternative ILM techniques, despite similar closure rates, foveal microstructural recovery is most complete following the pedicle transposition flap and least complete following the free flap.
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Membrana Basal , Perforaciones de la Retina , Colgajos Quirúrgicos , Tomografía de Coherencia Óptica , Agudeza Visual , Vitrectomía , Humanos , Perforaciones de la Retina/cirugía , Perforaciones de la Retina/diagnóstico , Perforaciones de la Retina/fisiopatología , Estudios Retrospectivos , Femenino , Masculino , Tomografía de Coherencia Óptica/métodos , Vitrectomía/métodos , Anciano , Membrana Basal/cirugía , Endotaponamiento/métodos , Colgajos Tisulares Libres , Estudios de Seguimiento , Resultado del TratamientoRESUMEN
Background and Objectives: Preeclampsia has been linked to an inflammatory response that may be brought on by endothelial cell dysfunction. This paper investigates the pathomechanism of syncytiotrophoblast basement membrane (STBM) damage and Placental Protein 13 (PP13) release, which may have a role in systemic endothelial dysfunction in preeclampsia. Materials and Methods: This comparative cross-sectional study involves 54 preeclampsia patients (27 early-onset preeclampsia and 27 late-onset preeclampsia) and 27 pregnant women with normal blood pressure. An enzyme-linked immunosorbent assay was performed to evaluate maternal blood levels of PP13. Following birth, a portion of the placenta was collected for transmission electron microscope (TEM) and immunohistochemical (IHC) analysis. The data were analyzed using STATA version 15. Results: PP13 expression in the placental syncytiotrophoblast was significantly lower in the early-onset preeclampsia, compared to late-onset preeclampsia and normotensive pregnancy, group (p < 0.001). In contrast, serum PP13 levels were found to be the highest in the early-onset preeclampsia group, although no significant difference were found in mean maternal serum levels of PP13 between the three groups. The decreased PP13 expression in placental syncytiotrophoblast can be attributed to the greater extent of damage in the STBM in early-onset preeclampsia that leads to the release of a larger amount of PP13 into maternal circulation. The hypothesis aligns with the TEM analysis results. Preeclamptic pregnancies showed placental syncytiotrophoblast aponeurosis, whereas normotensive pregnancies did not. Placental lesions and STBM shedding were found to be more pronounced in early-onset preeclampsia compared to late-onset preeclampsia. Conclusions: PP13 and STBM damage may play a role in systemic endothelial dysfunction in preeclampsia.