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1.
J Am Soc Nephrol ; 30(11): 2073-2090, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31653783

RESUMO

BACKGROUND: Necroptosis is a newly discovered cell death pathway that plays a critical role in AKI. The involvement of integrin-linked kinase (ILK) in necroptosis has not been studied. METHODS: We performed experiments in mice with an Ilk deletion in collecting duct (CD) principal cells (PCs), and cultured tubular epithelial cells treated with an ILK inhibitor or ILK siRNA knockdown. RESULTS: Ilk deletion in CD PCs resulted in acute tubular injury and early mortality in mice. Progressive interstitial fibrosis and inflammation associated with the activation of the canonical TGF-ß signaling cascade were detected in the kidneys of the mice lacking ILK in the CD PCs. In contrast to the minimal apoptosis detected in the animals' injured CDs, widespread necroptosis was present in ILK-deficient PCs, characterized by cell swelling, deformed mitochondria, and rupture of plasma membrane. In addition, ILK deficiency resulted in increased expression and activation of necroptotic proteins MLKL and RIPK3, and membrane translocation of MLKL in CD PCs. ILK inhibition and siRNA knockdown reduced cell survival in cultured tubular cells, concomitant with increased membrane accumulation of MLKL and/or phospho-MLKL. Administration of a necroptosis inhibitor, necrostatin-1, blocked cell death in vitro and significantly attenuated inflammation, interstitial fibrosis, and renal failure in ILK-deficient mice. CONCLUSIONS: The study demonstrates the critical involvement of ILK in necroptosis through modulation of the RIPK3 and MLKL pathway and highlights the contribution of CD PC injury to the development of inflammation and interstitial fibrosis of the kidney.

2.
PLoS One ; 13(1): e0191224, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29351342

RESUMO

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause (40-50%) of chronic kidney disease (CKD) in children. About 40 monogenic causes of CAKUT have so far been discovered. To date less than 20% of CAKUT cases can be explained by mutations in these 40 genes. To identify additional monogenic causes of CAKUT, we performed whole exome sequencing (WES) and homozygosity mapping (HM) in a patient with CAKUT from Indian origin and consanguineous descent. We identified a homozygous missense mutation (c.1336C>T, p.Arg446Cys) in the gene Von Willebrand factor A domain containing 2 (VWA2). With immunohistochemistry studies on kidneys of newborn (P1) mice, we show that Vwa2 and Fraser extracellular matrix complex subunit 1 (Fras1) co-localize in the nephrogenic zone of the renal cortex. We identified a pronounced expression of Vwa2 in the basement membrane of the ureteric bud (UB) and derivatives of the metanephric mesenchyme (MM). By applying in vitro assays, we demonstrate that the Arg446Cys mutation decreases translocation of monomeric VWA2 protein and increases translocation of aggregated VWA2 protein into the extracellular space. This is potentially due to the additional, unpaired cysteine residue in the mutated protein that is used for intermolecular disulfide bond formation. VWA2 is a known, direct interactor of FRAS1 of the Fraser-Complex (FC). FC-encoding genes and interacting proteins have previously been implicated in the pathogenesis of syndromic and/or isolated CAKUT phenotypes in humans. VWA2 therefore constitutes a very strong candidate in the search for novel CAKUT-causing genes. Our results from in vitro experiments indicate a dose-dependent neomorphic effect of the Arg446Cys homozygous mutation in VWA2.


Assuntos
Biomarcadores Tumorais/genética , Síndrome de Fraser/genética , Mutação de Sentido Incorreto , Anormalidades Urogenitais/genética , Refluxo Vesicoureteral/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Animais Recém-Nascidos , Biomarcadores Tumorais/química , Criança , Consanguinidade , Sequência Conservada , Éxons , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Homozigoto , Humanos , Masculino , Camundongos , Modelos Animais , Modelos Moleculares , Linhagem , Homologia de Sequência de Aminoácidos , Sistema Urogenital/crescimento & desenvolvimento , Sistema Urogenital/metabolismo
3.
J Biol Chem ; 293(9): 3039-3055, 2018 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-29317497

RESUMO

Slit guidance ligand 2 (SLIT2) is a large, secreted protein that binds roundabout (ROBO) receptors on multiple cell types, including neurons and kidney podocytes. SLIT2-ROBO-mediated signaling regulates neuronal migration and ureteric bud (UB) outgrowth during kidney development as well as glomerular filtration in adult kidneys. Additionally, SLIT2 binds Gremlin, an antagonist of bone morphogenetic proteins (BMPs), and BMP-Gremlin signaling also regulates UB formation. However, direct cross-talk between the ROBO2-SLIT2 and BMP-Gremlin signaling pathways has not been established. Here, we report the discovery of negative feedback between the SLIT2 and BMP-Gremlin signaling pathways. We found that the SLIT2-Gremlin interaction inhibited both SLIT2-ROBO2 signaling in neurons and Gremlin antagonism of BMP activity in myoblasts and fibroblasts. Furthermore, BMP2 down-regulated SLIT2 expression and promoter activity through canonical BMP signaling. Gremlin treatment, BMP receptor inhibition, and SMAD family member 4 (SMAD4) knockdown rescued BMP-mediated repression of SLIT2. BMP2 treatment of nephron progenitor cells derived from human embryonic stem cells decreased SLIT2 expression, further suggesting an interaction between the BMP2-Gremlin and SLIT2 pathways in human kidney cells. In conclusion, our study has revealed direct negative cross-talk between two pathways, previously thought to be unassociated, that may regulate both kidney development and adult tissue maintenance.

4.
IEEE Trans Image Process ; 26(9): 4321-4330, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28600248

RESUMO

Unsupervised outlier detection is a vital task and has high impact on a wide variety of applications domains, such as image analysis and video surveillance. It also gains long-standing attentions and has been extensively studied in multiple research areas. Detecting and taking action on outliers as quickly as possible are imperative in order to protect network and related stakeholders or to maintain the reliability of critical systems. However, outlier detection is difficult due to the one class nature and challenges in feature construction. Sequential anomaly detection is even harder with more challenges from temporal correlation in data, as well as the presence of noise and high dimensionality. In this paper, we introduce a novel deep structured framework to solve the challenging sequential outlier detection problem. We use autoencoder models to capture the intrinsic difference between outliers and normal instances and integrate the models to recurrent neural networks that allow the learning to make use of previous context as well as make the learners more robust to warp along the time axis. Furthermore, we propose to use a layerwise training procedure, which significantly simplifies the training procedure and hence helps achieve efficient and scalable training. In addition, we investigate a fine-tuning step to update all parameters set by incorporating the temporal correlation in the sequence. We further apply our proposed models to conduct systematic experiments on five real-world benchmark data sets. Experimental results demonstrate the effectiveness of our model, compared with other state-of-the-art approaches.

5.
Elife ; 62017 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-28394253

RESUMO

The maintenance of excitatory and inhibitory balance in the brain is essential for its function. Here we find that the developmental axon guidance receptor Roundabout 2 (Robo2) is critical for the maintenance of inhibitory synapses in the adult ventral tegmental area (VTA), a brain region important for the production of the neurotransmitter dopamine. Following selective genetic inactivation of Robo2 in the adult VTA of mice, reduced inhibitory control results in altered neural activity patterns, enhanced phasic dopamine release, behavioral hyperactivity, associative learning deficits, and a paradoxical inversion of psychostimulant responses. These behavioral phenotypes could be phenocopied by selective inactivation of synaptic transmission from local GABAergic neurons of the VTA, demonstrating an important function for Robo2 in regulating the excitatory and inhibitory balance of the adult brain.


Assuntos
Dopamina/metabolismo , Receptores Imunológicos/metabolismo , Transmissão Sináptica , Área Tegmentar Ventral/fisiologia , Animais , Comportamento Animal , Feminino , Técnicas de Inativação de Genes , Masculino , Camundongos Endogâmicos C57BL , Ácido gama-Aminobutírico/metabolismo
6.
J Am Soc Nephrol ; 28(8): 2364-2376, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28381549

RESUMO

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of CKD in the first three decades of life. However, for most patients with CAKUT, the causative mutation remains unknown. We identified a kindred with an autosomal dominant form of CAKUT. By whole-exome sequencing, we identified a heterozygous truncating mutation (c.279delG, p.Trp93fs*) of the nuclear receptor interacting protein 1 gene (NRIP1) in all seven affected members. NRIP1 encodes a nuclear receptor transcriptional cofactor that directly interacts with the retinoic acid receptors (RARs) to modulate retinoic acid transcriptional activity. Unlike wild-type NRIP1, the altered NRIP1 protein did not translocate to the nucleus, did not interact with RARα, and failed to inhibit retinoic acid-dependent transcriptional activity upon expression in HEK293 cells. Notably, we also showed that treatment with retinoic acid enhanced NRIP1 binding to RARα RNA in situ hybridization confirmed Nrip1 expression in the developing urogenital system of the mouse. In explant cultures of embryonic kidney rudiments, retinoic acid stimulated Nrip1 expression, whereas a pan-RAR antagonist strongly reduced it. Furthermore, mice heterozygous for a null allele of Nrip1 showed a CAKUT-spectrum phenotype. Finally, expression and knockdown experiments in Xenopus laevis confirmed an evolutionarily conserved role for NRIP1 in renal development. These data indicate that dominant NRIP1 mutations can cause CAKUT by interference with retinoic acid transcriptional signaling, shedding light on the well documented association between abnormal vitamin A levels and renal malformations in humans, and suggest a possible gene-environment pathomechanism in this disease.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Mutação , Proteínas Nucleares/genética , Transdução de Sinais/genética , Tretinoína/fisiologia , Sistema Urinário/anormalidades , Animais , Camundongos , Proteína 1 de Interação com Receptor Nuclear
7.
Am J Physiol Renal Physiol ; 312(6): F1016-F1025, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27654896

RESUMO

Protein mimotopes, or blocking peptides, are small therapeutic peptides that prevent protein-protein interactions by selectively mimicking a native binding domain. Inexpensive technology facilitates straightforward design and production of blocking peptides in sufficient quantities to allow preventive and therapeutic trials in both in vitro and in vivo experimental disease models. The kidney is an ideal peptide target, since small molecules undergo rapid filtration and efficient bulk absorption by tubular epithelial cells. Because the half-life of peptides is markedly prolonged in the kidneys compared with the bloodstream, blocking peptides are an attractive tool for treating diverse renal diseases, including ischemia, proteinuric states, such as membranous nephropathy and focal and segmental glomerulosclerosis, and renal cell carcinoma. Therapeutic peptides represent one of the fastest-growing reagent classes for novel drug development in human disease, partly because of their ease of administration, high binding affinity, and minimal off-target effects. This review introduces the concepts of blocking peptide design, production, and administration and highlights the potential use of therapeutic peptides to prevent or treat specific renal diseases.


Assuntos
Nefropatias/tratamento farmacológico , Rim/efeitos dos fármacos , Mimetismo Molecular , Peptídeos/uso terapêutico , Agentes Urológicos/uso terapêutico , Animais , Humanos , Rim/metabolismo , Rim/fisiopatologia , Nefropatias/metabolismo , Nefropatias/fisiopatologia , Terapia de Alvo Molecular , Peptídeos/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Transdução de Sinais/efeitos dos fármacos , Agentes Urológicos/metabolismo
8.
JCI Insight ; 1(19): e86934, 2016 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-27882344

RESUMO

The repulsive guidance cue SLIT2 and its receptor ROBO2 are required for kidney development and podocyte foot process structure, but the SLIT2/ROBO2 signaling mechanism regulating podocyte function is not known. Here we report that a potentially novel signaling pathway consisting of SLIT/ROBO Rho GTPase activating protein 1 (SRGAP1) and nonmuscle myosin IIA (NMIIA) regulates podocyte adhesion downstream of ROBO2. We found that the myosin II regulatory light chain (MRLC), a subunit of NMIIA, interacts directly with SRGAP1 and forms a complex with ROBO2/SRGAP1/NMIIA in the presence of SLIT2. Immunostaining demonstrated that SRGAP1 is a podocyte protein and is colocalized with ROBO2 on the basal surface of podocytes. In addition, SLIT2 stimulation inhibits NMIIA activity, decreases focal adhesion formation, and reduces podocyte attachment to collagen. In vivo studies further showed that podocyte-specific knockout of Robo2 protects mice from hypertension-induced podocyte detachment and albuminuria and also partially rescues the podocyte-loss phenotype in Myh9 knockout mice. Thus, we have identified SLIT2/ROBO2/SRGAP1/NMIIA as a potentially novel signaling pathway in kidney podocytes, which may play a role in regulating podocyte adhesion and attachment. Our findings also suggest that SLIT2/ROBO2 signaling might be a therapeutic target for kidney diseases associated with podocyte detachment and loss.


Assuntos
Proteínas Ativadoras de GTPase/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Miosina não Muscular Tipo IIA/metabolismo , Podócitos/citologia , Receptores Imunológicos/metabolismo , Transdução de Sinais , Animais , Movimento Celular , Rim , Camundongos , Camundongos Knockout
9.
Kidney Int ; 90(6): 1262-1273, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27591083

RESUMO

Primary glomerulocystic kidney disease is a special form of renal cystic disorder characterized by Bowman's space dilatation in the absence of tubular cysts. ZEB2 is a SMAD-interacting transcription factor involved in Mowat-Wilson syndrome, a congenital disorder with an increased risk for kidney anomalies. Here we show that deletion of Zeb2 in mesenchyme-derived nephrons with either Pax2-cre or Six2-cre causes primary glomerulocystic kidney disease without tubular cysts in mice. Glomerulotubular junction analysis revealed many atubular glomeruli in the kidneys of Zeb2 knockout mice, which explains the presence of glomerular cysts in the absence of tubular dilatation. Gene expression analysis showed decreased expression of early proximal tubular markers in the kidneys of Zeb2 knockout mice preceding glomerular cyst formation, suggesting that defects in proximal tubule development during early nephrogenesis contribute to the formation of congenital atubular glomeruli. At the molecular level, Zeb2 deletion caused aberrant expression of Pkd1, Hnf1ß, and Glis3, three genes causing glomerular cysts. Thus, Zeb2 regulates the morphogenesis of mesenchyme-derived nephrons and is required for proximal tubule development and glomerulotubular junction formation. Our findings also suggest that ZEB2 might be a novel disease gene in patients with primary glomerular cystic disease.


Assuntos
Doenças do Sistema Nervoso Central/genética , Esmalte Dentário/anormalidades , Diabetes Mellitus Tipo 2/genética , Proteínas de Homeodomínio/fisiologia , Doenças Renais Císticas/genética , Rim/embriologia , Proteínas Repressoras/fisiologia , Animais , Fator 1-beta Nuclear de Hepatócito/metabolismo , Rim/metabolismo , Camundongos Knockout , Proteínas Repressoras/metabolismo , Canais de Cátion TRPP/metabolismo , Transativadores/metabolismo , Homeobox 2 de Ligação a E-box com Dedos de Zinco
10.
Development ; 143(2): 356-66, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26681494

RESUMO

The developing lens is a powerful system for investigating the molecular basis of inductive tissue interactions and for studying cataract, the leading cause of blindness. The formation of tightly controlled cell-cell adhesions and cell-matrix junctions between lens epithelial (LE) cells, between lens fiber (LF) cells, and between these two cell populations enables the vertebrate lens to adopt a highly ordered structure and acquire optical transparency. Adhesion molecules are thought to maintain this ordered structure, but little is known about their identity or interactions. Cysteine-rich motor neuron 1 (Crim1), a type I transmembrane protein, is strongly expressed in the developing lens and its mutation causes ocular disease in both mice and humans. How Crim1 regulates lens morphogenesis is not understood. We identified a novel ENU-induced hypomorphic allele of Crim1, Crim1(glcr11), which in the homozygous state causes cataract and microphthalmia. Using this and two other mutant alleles, Crim1(null) and Crim1(cko), we show that the lens defects in Crim1 mouse mutants originate from defective LE cell polarity, proliferation and cell adhesion. Crim1 adhesive function is likely to be required for interactions both between LE cells and between LE and LF cells. We show that Crim1 acts in LE cells, where it colocalizes with and regulates the levels of active ß1 integrin and of phosphorylated FAK and ERK. The RGD and transmembrane motifs of Crim1 are required for regulating FAK phosphorylation. These results identify an important function for Crim1 in the regulation of integrin- and FAK-mediated LE cell adhesion during lens development.


Assuntos
Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Cristalino/citologia , Animais , Receptores de Proteínas Morfogenéticas Ósseas/genética , Linhagem Celular , Regulação da Expressão Gênica no Desenvolvimento , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Cristalino/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Organogênese/genética , Organogênese/fisiologia , Fosforilação , Transdução de Sinais/fisiologia
11.
Am J Hum Genet ; 97(2): 291-301, 2015 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-26235987

RESUMO

Congenital anomalies of the kidneys and urinary tract (CAKUT) are the most common cause of chronic kidney disease in the first three decades of life. Identification of single-gene mutations that cause CAKUT permits the first insights into related disease mechanisms. However, for most cases the underlying defect remains elusive. We identified a kindred with an autosomal-dominant form of CAKUT with predominant ureteropelvic junction obstruction. By whole exome sequencing, we identified a heterozygous truncating mutation (c.1010delG) of T-Box transcription factor 18 (TBX18) in seven affected members of the large kindred. A screen of additional families with CAKUT identified three families harboring two heterozygous TBX18 mutations (c.1570C>T and c.487A>G). TBX18 is essential for developmental specification of the ureteric mesenchyme and ureteric smooth muscle cells. We found that all three TBX18 altered proteins still dimerized with the wild-type protein but had prolonged protein half life and exhibited reduced transcriptional repression activity compared to wild-type TBX18. The p.Lys163Glu substitution altered an amino acid residue critical for TBX18-DNA interaction, resulting in impaired TBX18-DNA binding. These data indicate that dominant-negative TBX18 mutations cause human CAKUT by interference with TBX18 transcriptional repression, thus implicating ureter smooth muscle cell development in the pathogenesis of human CAKUT.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/genética , Genes Dominantes/genética , Músculo Liso/embriologia , Mutação/genética , Proteínas com Domínio T/genética , Ureter/embriologia , Sistema Urinário/anormalidades , Sequência de Bases , Ensaio de Desvio de Mobilidade Eletroforética , Exoma/genética , Células HEK293 , Humanos , Imuno-Histoquímica , Imunoprecipitação , Microscopia de Fluorescência , Dados de Sequência Molecular , Linhagem , Análise de Sequência de DNA
12.
Hum Genet ; 134(8): 905-16, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26026792

RESUMO

Congenital anomalies of the kidney and urinary tract (CAKUT) account for 40-50% of chronic kidney disease that manifests in the first two decades of life. Thus far, 31 monogenic causes of isolated CAKUT have been described, explaining ~12% of cases. To identify additional CAKUT-causing genes, we performed whole-exome sequencing followed by a genetic burden analysis in 26 genetically unsolved families with CAKUT. We identified two heterozygous mutations in SRGAP1 in 2 unrelated families. SRGAP1 is a small GTPase-activating protein in the SLIT2-ROBO2 signaling pathway, which is essential for development of the metanephric kidney. We then examined the pathway-derived candidate gene SLIT2 for mutations in cohort of 749 individuals with CAKUT and we identified 3 unrelated individuals with heterozygous mutations. The clinical phenotypes of individuals with mutations in SLIT2 or SRGAP1 were cystic dysplastic kidneys, unilateral renal agenesis, and duplicated collecting system. We show that SRGAP1 is expressed in early mouse nephrogenic mesenchyme and that it is coexpressed with ROBO2 in SIX2-positive nephron progenitor cells of the cap mesenchyme in developing rat kidney. We demonstrate that the newly identified mutations in SRGAP1 lead to an augmented inhibition of RAC1 in cultured human embryonic kidney cells and that the SLIT2 mutations compromise the ability of the SLIT2 ligand to inhibit cell migration. Thus, we report on two novel candidate genes for causing monogenic isolated CAKUT in humans.


Assuntos
Proteínas Ativadoras de GTPase , Peptídeos e Proteínas de Sinalização Intercelular , Mutação , Proteínas do Tecido Nervoso , Receptores Imunológicos , Transdução de Sinais/genética , Anormalidades Urogenitais , Refluxo Vesicoureteral , Animais , Exoma , Proteínas Ativadoras de GTPase/biossíntese , Proteínas Ativadoras de GTPase/genética , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/biossíntese , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Mesoderma/metabolismo , Camundongos , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/metabolismo , Ratos , Receptores Imunológicos/biossíntese , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Fatores de Risco , Anormalidades Urogenitais/embriologia , Anormalidades Urogenitais/genética , Refluxo Vesicoureteral/embriologia , Refluxo Vesicoureteral/genética
13.
Hum Mol Genet ; 24(8): 2375-89, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25574029

RESUMO

Cardiac left ventricular outflow tract (LVOT) defects represent a common but heterogeneous subset of congenital heart disease for which gene identification has been difficult. We describe a 46,XY,t(1;5)(p36.11;q31.2)dn translocation carrier with pervasive developmental delay who also exhibited LVOT defects, including bicuspid aortic valve (BAV), coarctation of the aorta (CoA) and patent ductus arteriosus (PDA). The 1p breakpoint disrupts the 5' UTR of AHDC1, which encodes AT-hook DNA-binding motif containing-1 protein, and AHDC1-truncating mutations have recently been described in a syndrome that includes developmental delay, but not congenital heart disease [Xia, F., Bainbridge, M.N., Tan, T.Y., Wangler, M.F., Scheuerle, A.E., Zackai, E.H., Harr, M.H., Sutton, V.R., Nalam, R.L., Zhu, W. et al. (2014) De Novo truncating mutations in AHDC1 in individuals with syndromic expressive language delay, hypotonia, and sleep apnea. Am. J. Hum. Genet., 94, 784-789]. On the other hand, the 5q translocation breakpoint disrupts the 3' UTR of MATR3, which encodes the nuclear matrix protein Matrin 3, and mouse Matr3 is strongly expressed in neural crest, developing heart and great vessels, whereas Ahdc1 is not. To further establish MATR3 3' UTR disruption as the cause of the proband's LVOT defects, we prepared a mouse Matr3(Gt-ex13) gene trap allele that disrupted the 3' portion of the gene. Matr3(Gt-ex13) homozygotes are early embryo lethal, but Matr3(Gt-ex13) heterozygotes exhibit incompletely penetrant BAV, CoA and PDA phenotypes similar to those in the human proband, as well as ventricular septal defect (VSD) and double-outlet right ventricle (DORV). Both the human MATR3 translocation breakpoint and the mouse Matr3(Gt-ex13) gene trap insertion disturb the polyadenylation of MATR3 transcripts and alter Matrin 3 protein expression, quantitatively or qualitatively. Thus, subtle perturbations in Matrin 3 expression appear to cause similar LVOT defects in human and mouse.


Assuntos
Coartação Aórtica/genética , Valva Aórtica/anormalidades , Permeabilidade do Canal Arterial/genética , Doenças das Valvas Cardíacas/genética , Proteínas Associadas à Matriz Nuclear/genética , Proteínas de Ligação a RNA/genética , Adolescente , Animais , Coartação Aórtica/metabolismo , Valva Aórtica/metabolismo , Pré-Escolar , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Permeabilidade do Canal Arterial/metabolismo , Feminino , Inativação Gênica , Doenças das Valvas Cardíacas/metabolismo , Ventrículos do Coração/anormalidades , Ventrículos do Coração/metabolismo , Humanos , Recém-Nascido , Masculino , Camundongos , Mutagênese Insercional , Proteínas Associadas à Matriz Nuclear/metabolismo , Proteínas de Ligação a RNA/metabolismo , Translocação Genética
14.
IEEE Trans Image Process ; 23(8): 3468-77, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24951692

RESUMO

Pose estimation from points with unknown correspondences currently is still a difficult problem in the field of computer vision. To solve this problem, the SoftSI algorithm is proposed, which can simultaneously obtain pose and correspondences. The SoftSI algorithm is based on the combination of the proposed PnP algorithm (the SI algorithm) and two singular value decomposition (SVD)-based shape description theorems. Other main contributions of this paper are: 1) two SVD-based shape description theorems are proposed; 2) by analyzing the calculation process of the SI algorithm, the method to avoid pose ambiguity is proposed; and 3) an acceleration method to quickly eliminate bad initial values for the SoftSI algorithm is proposed. The simulation results show that the SI algorithm is accurate while the SoftSI algorithm is fast, robust to noise, and has large convergence radius.


Assuntos
Algoritmos , Interpretação de Imagem Assistida por Computador/métodos , Imagem Tridimensional/métodos , Reconhecimento Automatizado de Padrão/métodos , Fotografação/métodos , Simulação por Computador , Aumento da Imagem/métodos , Modelos Estatísticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
Wiley Interdiscip Rev Syst Biol Med ; 5(3): 307-42, 2013 May-Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23408557

RESUMO

Congenital anomalies of the lower urinary tract (CALUT) are a family of birth defects of the ureter, the bladder, and the urethra. CALUT includes ureteral anomaliesc such as congenital abnormalities of the ureteropelvic junction (UPJ) and ureterovesical junction (UVJ), and birth defects of the bladder and the urethra such as bladder-exstrophy-epispadias complex (BEEC), prune belly syndrome (PBS), and posterior urethral valves (PUVs). CALUT is one of the most common birth defects and is often associated with antenatal hydronephrosis, vesicoureteral reflux (VUR), urinary tract obstruction, urinary tract infections (UTI), chronic kidney disease, and renal failure in children. Here, we discuss the current genetic and molecular knowledge about lower urinary tract development and genetic basis of CALUT in both human and mouse models. We provide an overview of the developmental processes leading to the formation of the ureter, the bladder, and the urethra, and different genes and signaling pathways controlling these developmental processes. Human genetic disorders that affect the ureter, the bladder and the urethra and associated gene mutations are also presented. As we are entering the postgenomic era of personalized medicine, information in this article may provide useful interpretation for the genetic and genomic test results collected from patients with lower urinary tract birth defects. With evidence-based interpretations, clinicians may provide more effective personalized therapies to patients and genetic counseling for their families.


Assuntos
Sistema Urinário/metabolismo , Mapeamento Cromossômico , Humanos , Transdução de Sinais/genética , Ureter/crescimento & desenvolvimento , Ureter/metabolismo , Uretra/crescimento & desenvolvimento , Uretra/metabolismo , Bexiga Urinária/crescimento & desenvolvimento , Bexiga Urinária/metabolismo , Sistema Urinário/anormalidades , Sistema Urinário/crescimento & desenvolvimento , Anormalidades Urogenitais , Refluxo Vesicoureteral/genética , Refluxo Vesicoureteral/metabolismo , Refluxo Vesicoureteral/patologia
16.
Cell Rep ; 2(1): 52-61, 2012 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-22840396

RESUMO

Robo2 is the cell surface receptor for the repulsive guidance cue Slit and is involved in axon guidance and neuronal migration. Nephrin is a podocyte slit-diaphragm protein that functions in the kidney glomerular filtration barrier. Here, we report that Robo2 is expressed at the basal surface of mouse podocytes and colocalizes with nephrin. Biochemical studies indicate that Robo2 forms a complex with nephrin in the kidney through adaptor protein Nck. In contrast to the role of nephrin that promotes actin polymerization, Slit2-Robo2 signaling inhibits nephrin-induced actin polymerization. In addition, the amount of F-actin associated with nephrin is increased in Robo2 knockout mice that develop an altered podocyte foot process structure. Genetic interaction study further reveals that loss of Robo2 alleviates the abnormal podocyte structural phenotype in nephrin null mice. These results suggest that Robo2 signaling acts as a negative regulator on nephrin to influence podocyte foot process architecture.


Assuntos
Proteínas de Membrana/antagonistas & inibidores , Podócitos/citologia , Podócitos/ultraestrutura , Receptores Imunológicos/fisiologia , Citoesqueleto de Actina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Animais , Células Cultivadas , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Modelos Biológicos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/fisiologia , Proteínas Oncogênicas/genética , Proteínas Oncogênicas/metabolismo , Proteínas Oncogênicas/fisiologia , Podócitos/metabolismo , Podócitos/fisiologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Receptor Cross-Talk/fisiologia , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
17.
PLoS One ; 6(9): e24763, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21949750

RESUMO

Antenatal hydronephrosis and vesicoureteral reflux (VUR) are common renal tract birth defects. We recently showed that disruption of the Robo2 gene is associated with VUR in humans and antenatal hydronephrosis in knockout mice. However, the natural history, causal relationship and developmental origins of these clinical conditions remain largely unclear. Although the hydronephrosis phenotype in Robo2 knockout mice has been attributed to the coexistence of ureteral reflux and obstruction in the same mice, this hypothesis has not been tested experimentally. Here we used noninvasive high-resolution micro-ultrasonography and pathological analysis to follow the progression of antenatal hydronephrosis in individual Robo2-deficient mice from embryo to adulthood. We found that hydronephrosis progressed continuously after birth with no spontaneous resolution. With the use of a microbubble ultrasound contrast agent and ultrasound-guided percutaneous aspiration, we demonstrated that antenatal hydronephrosis in Robo2-deficient mice is caused by high-grade VUR resulting from a dilated and incompetent ureterovesical junction rather than ureteral obstruction. We further documented Robo2 expression around the developing ureterovesical junction and identified early dilatation of ureteral orifice structures as a potential fetal origin of antenatal hydronephrosis and VUR. Our results thus demonstrate that Robo2 is crucial for the formation of a normal ureteral orifice and for the maintenance of an effective anti-reflux mechanism. This study also establishes a reproducible genetic mouse model of progressive antenatal hydronephrosis and primary high-grade VUR.


Assuntos
Hidronefrose/complicações , Hidronefrose/diagnóstico por imagem , Receptores Imunológicos/metabolismo , Refluxo Vesicoureteral/complicações , Refluxo Vesicoureteral/diagnóstico por imagem , Animais , Animais Recém-Nascidos , Progressão da Doença , Embrião de Mamíferos/anormalidades , Embrião de Mamíferos/patologia , Feto/anormalidades , Feto/patologia , Hidronefrose/embriologia , Hidronefrose/patologia , Rim/anormalidades , Rim/patologia , Camundongos , Camundongos Knockout , Fenótipo , Ultrassonografia , Refluxo Vesicoureteral/embriologia
18.
Am J Physiol Renal Physiol ; 300(5): F1262-5, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21325495

RESUMO

Vesicoureteral reflux (VUR) is a common pediatric anomaly linked to renal scarring and hypertension. Although there are many mouse VUR models, cystograms have previously only been performed in euthanized animals, thus preventing serial assessments for VUR in the same animal and not delineating "live" physiology. Our purpose was to develop a live murine cystogram assay that could be used serially to track reflux. We injected microbubbles via transurethral catheters into bladders of C57BL6/J and C3H/HeJ inbred mouse strains that are known to have low and high VUR rates, respectively. We performed ultrasound to visualize microbubbles in the renal pelvis to determine feasibility of the procedure. We then repeated the microbubble ultrasound using a transducer allowing for visualization of both kidneys and ureters simultaneously and for 3 dimensional (3D) reconstruction. We then performed "euthanized" cystograms on all mice for comparison. C3H/HeJ mice had a strong and persistent microbubble signal in the renal pelvis and ureters bilaterally with low-contrast infusion volumes (<100 µl) and similarly showed bilateral reflux by euthanized cystograms. With larger infused volumes (≥150 µl), C57BL6/J mice had small volumes of microbubbles in the renal pelvis that cleared quickly and did not show reflux on euthanized cystograms. Thus, using animal models of known VUR, we demonstrate the utility of contrast-enhanced ultrasound to visualize reflux in live mice.


Assuntos
Meios de Contraste , Microbolhas , Sistema Urinário/diagnóstico por imagem , Refluxo Vesicoureteral/diagnóstico por imagem , Animais , Modelos Animais de Doenças , Estudos de Viabilidade , Feminino , Imagem Tridimensional , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Fatores de Tempo , Ultrassonografia
19.
Kidney Int ; 79(10): 1099-112, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21270765

RESUMO

To determine which nephron segments require Notch signals for development, we conditionally deleted Rbpj, a transcription factor required for canonical Notch signaling, in nephrogenic progenitors (NPs) of the metanephric mesenchyme. The retinoic acid receptor-ß2 (Rarb2) promoter efficiently directed Cre-recombinase (Cre) activity to these progenitors. Conditional knockout of Rbpj in mice (Rarb2Cre(+)/Rbpj (f/-)) caused severe renal hypoplasia, as indicated by a 70-95% reduction in nephron number and the development of tubular cysts. To track the fate of NPs following Rarb2Cre expression, we labeled them with membrane-associated enhanced green fluorescent protein (GFP). In TomatoGFP(+)/Rarb2Cre(+) control mice, NPs differentiated into epithelia of all nephron segments, except into collecting ducts. In TomatoGFP(+)/Rarb2Cre(+)/Rbpj (f/-) conditional knockout mice, NPs developed into podocytes or distal tubular epithelia, indicating that canonical Notch signals were not required for mesenchymal-to-epithelial transition or for the specification of these nephron segments. Conversely, the few proximal tubules and associated cysts that developed in these mice were derived from the 5-10% of NPs that had failed to express Cre and, therefore, had intact Notch signaling. Thus, our fate mapping studies establish that the profound effect of Notch signaling on nephrogenesis is due to the specification of proximal but not distal tubules or podocytes.


Assuntos
Rim/embriologia , Receptores Notch/fisiologia , Transdução de Sinais/fisiologia , Células-Tronco/fisiologia , Animais , Apoptose , Proliferação de Células , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/fisiologia , Camundongos , Néfrons/embriologia , Receptores do Ácido Retinoico/genética , Receptores do Ácido Retinoico/fisiologia
20.
Am J Hum Genet ; 82(3): 712-22, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18319076

RESUMO

Apparently balanced chromosomal rearrangements in individuals with major congenital anomalies represent natural experiments of gene disruption and dysregulation. These individuals can be studied to identify novel genes critical in human development and to annotate further the function of known genes. Identification and characterization of these genes is the goal of the Developmental Genome Anatomy Project (DGAP). DGAP is a multidisciplinary effort that leverages the recent advances resulting from the Human Genome Project to increase our understanding of birth defects and the process of human development. Clinically significant phenotypes of individuals enrolled in DGAP are varied and, in most cases, involve multiple organ systems. Study of these individuals' chromosomal rearrangements has resulted in the mapping of 77 breakpoints from 40 chromosomal rearrangements by FISH with BACs and fosmids, array CGH, Southern-blot hybridization, MLPA, RT-PCR, and suppression PCR. Eighteen chromosomal breakpoints have been cloned and sequenced. Unsuspected genomic imbalances and cryptic rearrangements were detected, but less frequently than has been reported previously. Chromosomal rearrangements, both balanced and unbalanced, in individuals with multiple congenital anomalies continue to be a valuable resource for gene discovery and annotation.


Assuntos
Quebra Cromossômica , Anormalidades Congênitas/genética , Genoma Humano/genética , Desenvolvimento Humano , Mapeamento Cromossômico , Projeto Genoma Humano , Humanos
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