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PURPOSE: Although non-invasive prenatal testing (NIPT) based on cell-free DNA (cfDNA) in maternal plasma has been prevailing worldwide, low levels of fetal DNA fraction may lead to false-negative results. Since fetal cells in maternal blood provide a pure source of fetal genomic DNA, we aimed to establish a workflow to isolate and sequence fetal nucleated red blood cells (fNRBCs) individually as a target for NIPT. METHODS: Using male-bearing pregnancy cases, we isolated fNRBCs individually from maternal blood by FACS, and obtained their genomic sequence data through PCR screening with a Y-chromosome marker and whole-genome amplification (WGA)-based whole-genome sequencing. RESULTS: The PCR and WGA efficiencies of fNRBC candidates were consistently lower than those of control cells. Sequencing data analyses revealed that although the majority of the fNRBC candidates were confirmed to be of fetal origin, many of the WGA-based genomic libraries from fNRBCs were considered to have been amplified from a portion of genomic DNA. CONCLUSIONS: We established a workflow to isolate and sequence fNRBCs individually. However, our results demonstrated that, to make cell-based NIPT targeting fNRBCs feasible, cell isolation procedures need to be further refined such that the nuclei of fNRBCs are kept intact.
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Collagen degradation and proMMP-2 activation are major functions of MT1-MMP to promote cancer cell invasion. Since both processes require MT1-MMP homodimerization on the cell surface, herein we propose that the use of bifunctional inhibitors of this enzyme could represent an innovative approach to efficiently reduce tumor growth. A small series of symmetrical dimers derived from previously described monomeric arylsulfonamide hydroxamates was synthesized and tested in vitro on isolated MMPs. A nanomolar MT1-MMP inhibitor, compound 6, was identified and then submitted to cell-based assays on HT1080 fibrosarcoma cells. Dimer 6 reduced MT1-MMP-dependent proMMP-2 activation, collagen degradation and collagen invasion in a dose-dependent manner with better results even compared to its monomeric analogue 4. This preliminary study suggests that dimeric MT1-MMP inhibitors might be further developed and exploited as an alternative tool to reduce cancer cell invasion.
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Ácidos Hidroxámicos/farmacología , Metaloproteinasa 14 de la Matriz/metabolismo , Inhibidores de la Metaloproteinasa de la Matriz/farmacología , Sulfonamidas/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Colágeno/metabolismo , Diseño de Fármacos , Activación Enzimática/efectos de los fármacos , Humanos , Ácidos Hidroxámicos/síntesis química , Ácidos Hidroxámicos/química , Inhibidores de la Metaloproteinasa de la Matriz/síntesis química , Inhibidores de la Metaloproteinasa de la Matriz/química , Simulación de Dinámica Molecular , Estructura Molecular , Multimerización de Proteína/efectos de los fármacos , Sulfonamidas/síntesis química , Sulfonamidas/químicaRESUMEN
Membrane-type 1 matrix metalloproteinase (MT1-MMP) is a membrane-bound MMP that is highly expressed in cells with invading capacity, including fibroblasts and invasive cancer cells. However, pathways of MT1-MMP up-regulation are not clearly understood. A potential physiological stimulus for MT1-MMP expression is fibrillar collagen, and it has been shown that it up-regulates both MT1-MMP gene and functions in various cell types. However, the mechanisms of collagen-mediated MT1-MMP activation and its physiological relevance are not known. In this study, we identified discoidin domain receptor 2 (DDR2) as a crucial receptor that mediates this process in human fibroblasts. Knocking down DDR2, but not the ß1 integrin subunit, a common subunit for all collagen-binding integrins, inhibited the collagen-induced MT1-MMP-dependent activation of pro-MMP-2 and up-regulation of MT1-MMP at the gene and protein levels. Interestingly, DDR2 knockdown or pharmacological inhibition of DDR2 also inhibited the MT1-MMP-dependent cellular degradation of collagen film, suggesting that cell-surface collagen degradation by MT1-MMP involves DDR2-mediated collagen signaling. This DDR2-mediated mechanism is only present in non-transformed mesenchymal cells as collagen-induced MT1-MMP activation in HT1080 fibrosarcoma cells and MT1-MMP function in MDA-MB231 breast cancer cells were not affected by DDR kinase inhibition. DDR2 activation was found to be noticeably more effective when cells were stimulated by collagen without the non-helical telopeptide region compared with intact collagen fibrils. Furthermore, DDR2-dependent MT1-MMP activation by cartilage was found to be more efficient when the tissue was partially damaged. These data suggest that DDR2 is a microenvironment sensor that regulates fibroblast migration in a collagen-rich environment.
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Colágeno Tipo II/metabolismo , Receptor con Dominio Discoidina 2/metabolismo , Fibroblastos/metabolismo , Metaloproteinasa 14 de la Matriz/metabolismo , Animales , Neoplasias de la Mama/metabolismo , Cartílago/metabolismo , Bovinos , Línea Celular Tumoral , Femenino , Gelatina/química , Técnicas de Silenciamiento del Gen , Células HEK293 , Humanos , Integrina beta1/metabolismo , Integrinas/metabolismo , Microscopía Confocal , Reacción en Cadena de la Polimerasa , Unión Proteica , ARN Interferente Pequeño/metabolismo , Transducción de SeñalRESUMEN
The membrane-anchored collagenase membrane type 1 matrix metalloprotease (MT1-MMP) has been shown to play an essential role during epithelial tubulogenesis in 3D collagen matrices; however, its regulation during tubulogenesis is not understood. Here, we report that degradation of collagen in polarized epithelial cells is post-translationally regulated by changing the localization of MT1-MMP from the apical to the basal surface. MT1-MMP predominantly localizes at the apical surface in inert polarized epithelial cells, whereas treatment with HGF induced basal localization of MT1-MMP followed by collagen degradation. The basal localization of MT1-MMP requires the ectodomains of the enzyme because deletion of the MT-loop region or the hemopexin domain inhibited basal localization of the enzyme. TGFß is a well-known inhibitor of tubulogenesis and our data indicate that its mechanism of inhibition is, at least in part, due to inhibition of MT1-MMP localization to the basal surface. Interestingly, however, the effect of TGFß was found to be bi-phasic: at high doses it effectively inhibited basal localization of MT1-MMP, whereas at lower doses tubulogenesis and basal localization of MT1-MMP was promoted. Taken together, these data indicate that basal localization of MT1-MMP is a key factor promoting the degradation of extracellular matrix by polarized epithelial cells, and that this is an essential part of epithelial morphogenesis in 3D collagen.
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Membrana Celular/enzimología , Colágeno/metabolismo , Metaloproteinasa 14 de la Matriz/metabolismo , Animales , Movimiento Celular , Polaridad Celular , Medios de Cultivo , Perros , Factor de Crecimiento de Hepatocito/fisiología , Humanos , Células de Riñón Canino Madin Darby , Ratones , Organogénesis , Transporte de Proteínas , ProteolisisRESUMEN
Localization of membrane type I matrix metalloproteinase (MT1-MMP) to the leading edge is thought to be a crucial step during cancer cell invasion. However, its mechanisms and functional impact on cellular invasion have not been clearly defined. In this report, we have identified the MT-LOOP, a loop region in the catalytic domain of MT1-MMP ((163)PYAYIREG(170)), as an essential region for MT1-MMP to promote cellular invasion. Deletion of the MT-LOOP effectively inhibited functions of MT1-MMP on the cell surface, including proMMP-2 activation, degradation of gelatin and collagen films, and cellular invasion into a collagen matrix. This is not due to loss of the catalytic function of MT1-MMP but due to inefficient localization of the enzyme to ß1-integrin-rich cell adhesion complexes at the plasma membrane. We also found that an antibody that specifically recognizes the MT-LOOP region of MT1-MMP (LOOPAb) inhibited MT1-MMP functions, fully mimicking the phenotype of the MT-LOOP deletion mutant. We therefore propose that the MT-LOOP region is an interface for molecular interactions that mediate enzyme localization to cell adhesion complexes and regulate MT1-MMP functions. Our findings have revealed a novel mechanism regulating MT1-MMP during cellular invasion and have identified the MT-LOOP as a potential exosite target region to develop selective MT1-MMP inhibitors.
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Adhesión Celular/fisiología , Metaloproteinasa 14 de la Matriz/química , Metaloproteinasa 14 de la Matriz/fisiología , Invasividad Neoplásica/fisiopatología , Secuencia de Aminoácidos , Animales , Células COS , Chlorocebus aethiops , Precursores Enzimáticos/metabolismo , Matriz Extracelular/fisiología , Gelatinasas/metabolismo , Células HeLa , Humanos , Metaloproteinasa 14 de la Matriz/genética , Modelos Biológicos , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Eliminación de SecuenciaRESUMEN
Many countries, including Japan, are experiencing declining birth rates. Assisted reproductive technologies have consistently demonstrated good results in resolving infertility. Although the development of fertilized eggs into blastocysts has been recognized as a crucial step in assisted reproductive technologies, the involved mechanisms are currently unclear. Here, we established a new culture system for the in vitro development of fertilized eggs into blastocysts. In the Transwell culture system, the rate of blastocysts hatching from fertilized eggs cultured with adipose-derived stem cells (ASCs) was significantly higher than that of blastocysts cultured only with fertilized eggs. Gene ontology analysis revealed that the developed blastocysts displayed essential gene expression patterns in mature blastocysts. Additionally, when cultured with 3rd-passage ASCs, the developed blastocysts expressed the core genes for blastocyst maturation and antioxidant properties compared to those cultured only with fertilized eggs or cultured with 20th-passage ASCs. These results suggest that the Transwell culture system may imitate the in vivo tubal culture state for fertilized eggs. Exosomes derived from stem cells with stemness potential play a powerful role in the development of blastocysts from fertilized eggs. Additionally, the exosomes expressed specific microRNAs; therefore, the Transwell culture system resulted in a higher rate of pregnancy. In future, the extraction of their own extracellular vesicles from the culture medium might contribute to the development of novel assisted reproductive technologies.
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BACKGROUND/AIM: Age-related decline in the number of ovulations and ovum quality are major causes of female infertility, and stem cells have been reported to be effective in tissue regeneration. However, current therapeutic modalities are inadequate. This study investigated the effects of adipose-derived mesenchymal stem cells (ASCs) on ovarian functions in aged mice. MATERIALS AND METHODS: Following the characterization of ASCs using flow cytometry, the effects of ASCs on the number of ovulations, fertilization rate, and blastocyst-formation rate were investigated. In addition, the number of ovarian follicles and serum anti-Müllerian hormone (AMH) levels were examined. ASCs marked with Kusabira Orange were used to examine the location after cell administration. The quality of ovulated oocytes was analyzed using next-generation RNA sequencing. RESULTS: ASCs showed characteristics of mesenchymal stem cells and were distributed to various organs, including the ovarian stroma. The transplantation resulted in increased number of oocytes and ovulation in the ovaries and increased AMH values. Genetic analysis revealed improved oocyte quality and increased fertilization and blastocyst-formation rates. CONCLUSION: ASC therapy may be effective in improving fertility in older women.
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Tejido Adiposo , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Oocitos , Ovario , Animales , Femenino , Trasplante de Células Madre Mesenquimatosas/métodos , Ratones , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/citología , Tejido Adiposo/citología , Envejecimiento/fisiología , Hormona Antimülleriana/sangre , Hormona Antimülleriana/metabolismo , Folículo Ovárico/metabolismo , Folículo Ovárico/citología , OvulaciónRESUMEN
Cis-regulatory modules that drive precise spatial-temporal patterns of gene expression are central to the process of metazoan development. We describe a new computational strategy to annotate genomic sequences based on their "pattern generating potential" and to produce quantitative descriptions of transcriptional regulatory networks at the level of individual protein-module interactions. We use this approach to convert the qualitative understanding of interactions that regulate Drosophila segmentation into a network model in which a confidence value is associated with each transcription factor-module interaction. Sequence information from multiple Drosophila species is integrated with transcription factor binding specificities to determine conserved binding site frequencies across the genome. These binding site profiles are combined with transcription factor expression information to create a model to predict module activity patterns. This model is used to scan genomic sequences for the potential to generate all or part of the expression pattern of a nearby gene, obtained from available gene expression databases. Interactions between individual transcription factors and modules are inferred by a statistical method to quantify a factor's contribution to the module's pattern generating potential. We use these pattern generating potentials to systematically describe the location and function of known and novel cis-regulatory modules in the segmentation network, identifying many examples of modules predicted to have overlapping expression activities. Surprisingly, conserved transcription factor binding site frequencies were as effective as experimental measurements of occupancy in predicting module expression patterns or factor-module interactions. Thus, unlike previous module prediction methods, this method predicts not only the location of modules but also their spatial activity pattern and the factors that directly determine this pattern. As databases of transcription factor specificities and in vivo gene expression patterns grow, analysis of pattern generating potentials provides a general method to decode transcriptional regulatory sequences and networks.
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Tipificación del Cuerpo , Biología Computacional/métodos , Drosophila/embriología , Elementos de Facilitación Genéticos , Regulación del Desarrollo de la Expresión Génica , Redes Reguladoras de Genes , Factores de Transcripción/metabolismo , Animales , Sitios de Unión , Tipificación del Cuerpo/genética , Drosophila/genética , Drosophila/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Modelos Genéticos , Unión Proteica , Programas Informáticos , Factores de Transcripción/genéticaRESUMEN
Chordomas are rare, locally aggressive, primary bone tumors derived from primitive notochord remnants. They almost always arise within the axial skeleton, particularly in the skull base and the sacrococcygeal region. They usually present as extradural tumors, but rarely, they present as entirely intradural tumors. This report describes a case of intradural chordoma that mimicked an epidermoid cyst. A 72-year-old woman was incidentally found to have a prepontine extra-axial mass on magnetic resonance imaging. The mass gradually increased in size, and she felt discomfort in the right cheek area. The mass showed similar signal intensity to cerebrospinal fluid on T1-weighted images and T2-weighted images, but high signal intensity on fluid-attenuated inversion recovery images and diffusion-weighted images. Because the presence of very faint contrast enhancement was not noticed, the mass was preoperatively diagnosed as an epidermoid cyst. Tumor resection was performed, and the histopathological diagnosis was chondroid chordoma. Since intradural chordoma may resemble an epidermoid cyst on imaging, radiologists should check carefully for the presence of contrast enhancement and suggest the possibility of intradural chordoma.
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Currently, there is no surgical assistance system that can perform a three-dimensional (3D) planned total hip arthroplasty (THA) by methods other than surgical assistance navigation or robots. However, they are expensive, cumbersome, and subject to additional invasiveness, so there is a need for a simpler and less expensive 3D surgical support system. In this study, THA was performed using the anterolateral approach (Watson-Jones) in the supine position in 23 subjects to examine the efficacy and safety of a patient-specific femoral guide linked to 3D surgery support software. In 48% of the subjects, the difference in anterior torsion angle from the preoperative plan was within ±5 degrees, while in 83% of the subjects, the difference was within ±10 degrees. The 95% confidence interval (4.61-8.70) of the absolute difference did not fall below the pre-defined threshold of 7.2 degrees (p = 0.293). No adverse events were observed other than 2 cases (8.7%) of hemorrhage that required a blood transfusion. We confirmed the efficacy and safety of the patient-specific femoral guide in anterolateral supine approach THA.
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Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Cirugía Asistida por Computador , Humanos , Artroplastia de Reemplazo de Cadera/métodos , Fémur/cirugía , Programas Informáticos , Cirugía Asistida por Computador/métodosRESUMEN
Niemann-Pick disease type C1 (NPC1) is a fatal lysosomal storage disorder characterized by progressive neuronal degeneration. Its key pathogenic events remain largely unknown. We have, herein, found that neonatal BM-derived cell transplantation can ameliorate Purkinje cell degeneration in NPC1 mice. We subsequently addressed the impact of the peripheral immune system on the neuropathogenesis observed in NPC1 mice. The depletion of mature lymphocytes promoted NPC1 phenotypes, thereby suggesting a neuroprotective effect of lymphocytes. Moreover, the peripheral infusion of CD4-positive cells (specifically, of regulatory T cells) from normal healthy donor ameliorated the cerebellar ataxic phenotype and enhanced the survival of Purkinje cells. Conversely, the depletion of regulatory T cells enhanced the onset of the neurological phenotype. On the other hand, circulating inflammatory monocytes were found to be involved in the progression of Purkinje cell degeneration, whereas the depletion of resident microglia had little effect. Our findings reveal a novel role of the adaptive and the innate immune systems in NPC1 neuropathology.
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Enfermedad de Niemann-Pick Tipo C , Células de Purkinje , Ratones , Animales , Células de Purkinje/metabolismo , Células de Purkinje/patología , Enfermedad de Niemann-Pick Tipo C/genética , Cerebelo/metabolismo , Sistema Inmunológico/metabolismo , Microglía/metabolismoRESUMEN
Homodimerization is an essential step for membrane type 1 matrix metalloproteinase (MT1-MMP) to activate proMMP-2 and to degrade collagen on the cell surface. To uncover the molecular basis of the hemopexin (Hpx) domain-driven dimerization of MT1-MMP, a crystal structure of the Hpx domain was solved at 1.7 Å resolution. Two interactions were identified as potential biological dimer interfaces in the crystal structure, and mutagenesis studies revealed that the biological dimer possesses a symmetrical interaction where blades II and III of molecule A interact with blades III and II of molecule B. The mutations of amino acids involved in the interaction weakened the dimer interaction of Hpx domains in solution, and incorporation of these mutations into the full-length enzyme significantly inhibited dimer-dependent functions on the cell surface, including proMMP-2 activation, collagen degradation, and invasion into the three-dimensional collagen matrix, whereas dimer-independent functions, including gelatin film degradation and two-dimensional cell migration, were not affected. These results shed light on the structural basis of MT1-MMP dimerization that is crucial to promote cellular invasion.
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Matriz Extracelular/enzimología , Hemopexina/química , Hemopexina/metabolismo , Metaloproteinasa 14 de la Matriz/química , Metaloproteinasa 14 de la Matriz/metabolismo , Animales , Células COS , Chlorocebus aethiops , Cristalografía , Dimerización , Activación Enzimática/fisiología , Células HeLa , Hemopexina/genética , Humanos , Metaloproteinasa 14 de la Matriz/genética , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Mutagénesis , Estructura Terciaria de Proteína , Solubilidad , Relación Estructura-ActividadRESUMEN
MT1-MMP plays a crucial role in promoting the cellular invasion of cancer cells by degrading the extracellular matrix to create a path for migration. During this process, its localization at the leading edge of migrating cells is critical, and it is achieved by targeted transport of MT1-MMP-containing vesicles along microtubules by kinesin superfamily motor proteins (KIFs). Here we identified three KIFs involved in MT1-MMP vesicle transport: KIF3A, KIF13A, and KIF9. Knockdown of KIF3A and KIF13A effectively inhibited MT1-MMP-dependent collagen degradation and invasion, while knockdown of KIF9 increased collagen degradation and invasion. Our data suggest that KIF3A/KIF13A dependent MT1-MMP vesicles transport takes over upon KIF9 knockdown. Live-cell imaging analyses have indicated that KIF3A and KIF13A coordinate to transport the same MT1-MMP-containing vesicles from the trans-Golgi to the endosomes, and KIF13A alone transports the vesicle from the endosome to the plasma membrane. Taken together, we have identified a unique interplay between three KIFs to regulate leading edge localization of MT1-MMP and MT1-MMP-dependent cancer cell invasion.
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Cinesinas , Metaloproteinasa 14 de la Matriz , Línea Celular Tumoral , Movimiento Celular , Endosomas/metabolismo , Matriz Extracelular/metabolismo , Humanos , Cinesinas/genética , Metaloproteinasa 14 de la Matriz/genética , Metaloproteinasa 14 de la Matriz/metabolismo , Invasividad NeoplásicaRESUMEN
Although podocyte damage is known to be responsible for the development of minimal-change disease (MCD), the underlying mechanism remains to be elucidated. Previously, using a rat MCD model, we showed that endoplasmic reticulum (ER) stress in the podocytes was associated with the heavy proteinuric state and another group reported that a mammalian target of rapamycin complex 1 (mTORC1) inhibitor protected against proteinuria. In this study, which utilized a rat MCD model, a combination of immunohistochemistry, dual immunofluorescence and confocal microscopy, western blot analysis, and quantitative real-time RT-PCR revealed co-activation of the unfolded protein response (UPR), which was induced by ER stress, and mTORC1 in glomerular podocytes before the onset of proteinuria and downregulation of nephrin at the post-translational level at the onset of proteinuria. Podocyte culture experiments revealed that mTORC1 activation preceded the UPR that was associated with a marked decrease in the energy charge. The mTORC1 inhibitor everolimus completely inhibited proteinuria through a reduction in both mTORC1 and UPR activity and preserved nephrin expression in the glomerular podocytes. In conclusion, mTORC1 activation may perturb the regulatory system of energy metabolism primarily by promoting energy consumption and inducing the UPR, which underlie proteinuria in MCD.
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Estrés del Retículo Endoplásmico/fisiología , Nefrosis Lipoidea/metabolismo , Podocitos/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Respuesta de Proteína Desplegada/fisiología , Animales , Western Blotting , Células Cultivadas , Everolimus , Técnica del Anticuerpo Fluorescente , Inmunohistoquímica , Microscopía Confocal , Nefrosis Lipoidea/etiología , Ratas , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sirolimus/análogos & derivados , Estadísticas no Paramétricas , Serina-Treonina Quinasas TOR/antagonistas & inhibidoresRESUMEN
Molecular mechanisms and signaling pathways leading to cellular proliferation and lesion formation in the crescentic glomerulonephritis (CGN) remain elusive. In the present study we have explored a potential role of the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway and amino acid transporter (LAT) in the pathogenesis of CGN. Immunohistochemistry and western blot analysis of glomeruli isolated from a rat model of CGN revealed that activation of mTORC1 preceded crescent formation in glomerular parietal epithelial cells (PECs) and podocytes. Daily treatment of rats with the mTOR inhibitor everolimus just after induction of CGN was not beneficial and instead led to increased cellular necrosis of PECs. However, daily treatment starting 7 days after the onset of CGN was beneficial and maintained intact glomeruli. Out of three forms of L-type neutral amino acid transporters (LAT1-LAT3) studied here, only LAT2 was found to be upregulated in the PECs and podocytes in advance of the crescent formation as well as in the crescent lesion itself. Cell culture study revealed that plasma membrane expression of LAT2 markedly stimulated mTORC1 signaling pathway, which was significantly abrogated by coexistence of LAT inhibitor. Finally, LAT inhibitor significantly abrogated development of crescent formation of CGN on day 7. Our data suggest that LAT2 may have a pivotal role in the pathogenesis of CGN by activating the mTORC1 pathway in the glomerular epithelial cells.
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Sistema de Transporte de Aminoácidos y+/fisiología , Cadenas Ligeras de la Proteína-1 Reguladora de Fusión/fisiología , Glomerulonefritis/fisiopatología , Serina-Treonina Quinasas TOR/metabolismo , Animales , Secuencia de Bases , Western Blotting , Cartilla de ADN , Femenino , Glomerulonefritis/etiología , Inmunohistoquímica , Ratas , Ratas Endogámicas WKY , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de SeñalRESUMEN
Dupuytren's Disease (DD) is a common fibroproliferative disease of the palmar fascia. We previously identified a causal association with a non-synonymous variant (rs1042704, p.D273N) in MMP14 (encoding MT1-MMP). In this study, we investigated the functional consequences of this variant, and demonstrated that the variant MT1-MMP (MT1-N273) exhibits only 17% of cell surface collagenolytic activity compared to the ancestral enzyme (MT1-D273). Cells expressing both MT1-D273 and MT1-N273 in a 1:1 ratio, mimicking the heterozygous state, possess 38% of the collagenolytic activity compared to the cells expressing MT1-D273, suggesting that MT1-N273 acts in a dominant negative manner. Consistent with the above observation, patient-derived DD myofibroblasts with the alternate allele demonstrated around 30% of full collagenolytic activity detected in ancestral G/G genotype cells, regardless of the heterozygous (G/A) or homozygous (A/A) state. Small angle X-ray scattering analysis of purified soluble Fc-fusion enzymes allowed us to construct a 3D-molecular envelope of MT1-D273 and MT1-N273, and demonstrate altered flexibility and conformation of the ectodomains due to D273 to N substitution. Taking together, rs1042704 significantly reduces collagen catabolism in tissue, which tips the balance of homeostasis of collagen in tissue, contributing to the fibrotic phenotype of DD. Since around 30% of the worldwide population have at least one copy of the low collagenolytic alternate allele, further investigation of rs1042704 across multiple pathologies is needed.
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Colágeno/metabolismo , Contractura de Dupuytren/genética , Metaloproteinasa 14 de la Matriz/genética , Metaloproteinasa 14 de la Matriz/metabolismo , Polimorfismo de Nucleótido Simple , Animales , Células COS , Chlorocebus aethiops , Contractura de Dupuytren/metabolismo , Humanos , Metaloproteinasa 14 de la Matriz/química , Modelos Moleculares , Conformación Proteica , Dominios Proteicos , Dispersión del Ángulo Pequeño , Difracción de Rayos XRESUMEN
LAT3 is a Na+-independent neutral l-amino acid transporter recently isolated from a human hepatocellular carcinoma cell line. Although liver, skeletal muscle, and pancreas are known to express LAT3, the tissue distribution and physiologic function of this transporter are not completely understood. Here, we observed that glomeruli express LAT3. Immunofluorescence, confocal microscopy, and immunoelectron microscopy revealed that LAT3 localizes to the apical plasma membrane of podocyte foot processes. In mice, starvation upregulated glomerular LAT3, phosphorylated AKT1, reconstituted the actin network, and elongated foot processes. In the fetal kidney, we observed intense LAT3 expression at the capillary loops stage of renal development. Finally, zebrafish morphants lacking lat3 function showed collapsed glomeruli with thickened glomerular basement membranes. Permeability studies of the glomerular filtration barrier in these zebrafish morphants demonstrated a disruption of selective glomerular permeability. Our data suggest that LAT3 may play a crucial role in the development and maintenance of podocyte structure and function by regulating protein synthesis and the actin cytoskeleton.
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Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Diferenciación Celular/fisiología , Glomérulos Renales/metabolismo , Podocitos/metabolismo , Actinas/metabolismo , Sistemas de Transporte de Aminoácidos Básicos/genética , Animales , Membrana Celular/metabolismo , Citoesqueleto/metabolismo , Femenino , Membrana Basal Glomerular/metabolismo , Tasa de Filtración Glomerular/fisiología , Humanos , Glomérulos Renales/citología , Glomérulos Renales/embriología , Masculino , Ratones , Ratones Endogámicos ICR , Fosforilación , Podocitos/citología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Pez Cebra , Proteínas de Pez Cebra/metabolismoRESUMEN
Transcription factors (TFs) play a pivotal role in determining cell states, yet our understanding of the causative relationship between TFs and cell states is limited. Here, we systematically examine the state changes of human pluripotent embryonic stem cells (hESCs) by the large-scale manipulation of single TFs. We establish 2,135 hESC lines, representing three clones each of 714 doxycycline (Dox)-inducible genes including 481 TFs, and obtain 26,998 microscopic cell images and 2,174 transcriptome datasets-RNA sequencing (RNA-seq) or microarrays-48 h after the presence or absence of Dox. Interestingly, the expression of essentially all the genes, including genes located in heterochromatin regions, are perturbed by these TFs. TFs are also characterized by their ability to induce differentiation of hESCs into specific cell lineages. These analyses help to provide a way of classifying TFs and identifying specific sets of TFs for directing hESC differentiation into desired cell types.
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Células Madre Embrionarias Humanas/metabolismo , Factores de Transcripción/metabolismo , Diferenciación Celular/fisiología , Línea Celular , Células Madre Embrionarias Humanas/citología , Humanos , Análisis de la Célula Individual/métodosRESUMEN
Nephrin is an essential structural component of the glomerular slit diaphragm (SD), a highly organized intercellular junction that constitutes the ultrafiltration barrier of the kidney. Recent studies have identified two additional nephrin-interacting SD proteins (NEPH1 and NEPH2), suggesting that the zipper-like pattern of the SD is formed through complex intra- and intermolecular interactions of these proteins. However, the complexity of the SD structure suggests that additional SD components remain to be discovered. In this study, we identified galectin-1 (Gal-1) as a new component of the SD, binding to the ectodomain of nephrin. Using dual-immunofluorescence and confocal microscopy and dual-immunoelectron microscopy, we found Gal-1 co-localizing with the ectodomain of nephrin at the SD in normal human kidney. By immunoprecipitation and surface plasmon resonance, we confirmed a direct molecular interaction between Gal-1 and nephrin. Moreover, recombinant Gal-1 induced tyrosine phosphorylation of the cytoplasmic domain of nephrin and activation of the extracellular signal-regulated kinase 1/2 in podocytes. We also showed that podocytes are a major site of biosynthesis of Gal-1 in the glomerulus and that the normal expression patterns and levels of Gal-1 are altered in patients with minimal change nephrotic syndrome. Finally, in puromycin aminonucleoside-induced rat nephrosis, an apparent reduction in the levels of Gal-1 and nephrin around the onset of heavy proteinuria was also revealed. Our data present Gal-1 as a new extracellular ligand of nephrin localized at the glomerular SD, and provide further insight into the complex molecular organization, interaction, and structure of the SD, which is an active site of intracellular signaling necessary for podocyte function.
Asunto(s)
Galectina 1/metabolismo , Riñón/metabolismo , Nefrosis Lipoidea/metabolismo , Podocitos/metabolismo , Animales , Línea Celular Transformada , Modelos Animales de Enfermedad , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Galectina 1/farmacología , Humanos , Riñón/patología , Proteínas de la Membrana/metabolismo , Microscopía Confocal , Microscopía Fluorescente , Microscopía Inmunoelectrónica , Proteína Quinasa 3 Activada por Mitógenos/biosíntesis , Nefrosis Lipoidea/inducido químicamente , Nefrosis Lipoidea/patología , Fosforilación , Podocitos/efectos de los fármacos , Podocitos/patología , Ratas , Proteínas Recombinantes , Tirosina/metabolismoRESUMEN
Pericellular degradation of interstitial collagens is a crucial event for cells to migrate through the dense connective tissue matrices, where collagens exist as insoluble fibers. A key proteinase that participates in this process is considered to be membrane-type 1 matrix metalloproteinase (MT1-MMP or MMP-14), but little is known about the mechanism by which it cleaves the insoluble collagen. Here we report that homodimerization of MT1-MMP through its hemopexin (Hpx) domain is essential for cleaving type I collagen fibers at the cell surface. When dimerization was blocked by coexpressing either a membrane-bound or a soluble form of the Hpx domain, cell surface collagenolytic activity was inhibited in a dose-dependent manner. When MMP-13, a soluble collagenase active as a monomer in solution, was expressed as a membrane-anchored form on the cell surface, homodimerization was also required to cleave collagen. Our results introduce a new concept in that pericellular collagenolysis is regulated by correct molecular assembly of the membrane-anchored collagenase, thereby governing the directionality of the cell to migrate in tissue.