RESUMO
The role extracellular matrix (ECM) in multiple events of morphogenesis has been well described, little is known about its specific role in early eye development. One of the first morphogenic events in lens development is placodal thickening, which converts the presumptive lens ectoderm from cuboidal to pseudostratified epithelium. This process occurs in the anterior pre-placodal ectoderm when the optic vesicle approaches the cephalic ectoderm and is regulated by transcription factor Pax6 and secreted BMP4. Since cells and ECM have a dynamic relationship of interdependence and modulation, we hypothesized that the ECM evolves with cell shape changes during lens placode formation. This study investigates changes in optic ECM including both protein distribution deposition, extracellular gelatinase activity and gene expression patterns during early optic development using chicken and mouse models. In particular, the expression of Timp2, a metalloprotease inhibitor, corresponds with a decrease in gelatinase activity within the optic ECM. Furthermore, we demonstrate that optic ECM remodeling depends on BMP signaling in the placode. Together, our findings suggest that the lens placode plays an active role in remodeling the optic ECM during early eye development.
Assuntos
Matriz Extracelular , Regulação da Expressão Gênica no Desenvolvimento , Cristalino , Fator de Transcrição PAX6 , Animais , Matriz Extracelular/metabolismo , Camundongos , Cristalino/metabolismo , Cristalino/crescimento & desenvolvimento , Cristalino/citologia , Fator de Transcrição PAX6/metabolismo , Fator de Transcrição PAX6/genética , Proteínas do Olho/metabolismo , Proteínas do Olho/genética , Proteína Morfogenética Óssea 4/metabolismo , Proteína Morfogenética Óssea 4/genética , Embrião de Galinha , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Inibidor Tecidual de Metaloproteinase-2/metabolismo , Inibidor Tecidual de Metaloproteinase-2/genética , Fatores de Transcrição Box Pareados/metabolismo , Fatores de Transcrição Box Pareados/genética , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética , Transdução de Sinais , Galinhas/genética , Olho/metabolismo , Olho/crescimento & desenvolvimento , Olho/embriologiaRESUMO
LAMA2-related dystrophies (LAMA2-RD) constitute a rare neuromuscular disorder with a broad spectrum of phenotypic severity. Our understanding of the genotype-phenotype correlations in this condition remains incomplete, and reliable clinical data for clinical trial readiness is limited. In this retrospective study, we reviewed the genetic data and medical records of 114 LAMA2-RD patients enrolled at seven research centers in Brazil. We identified 58 different pathogenic variants, including 21 novel ones. Six variants were more prevalent and were present in 81.5% of the patients. Notably, the c.1255del, c.2049_2050del, c.3976 C>T, c.5234+1G>A, and c.4739dup variants were found in patients unable to walk and without cortical malformation. In contrast, the c.2461A>C variant was present in patients who could walk unassisted. Among ambulatory patients, missense variants were more prevalent (p < 0.0001). Although no specific hotspot regions existed in the LAMA2, 51% of point mutations were in the LN domain, and 88% of the missense variants were found within this domain. Functional analysis was performed in one intronic variant (c.4960-17C>A) and revealed an out-of-frame transcript, indicating that the variant creates a cryptic splicing site (AG). Our study has shed light on crucial phenotype-genotype correlations and provided valuable insights, particularly regarding the Latin American population.
Assuntos
Estudos de Associação Genética , Laminina , Humanos , Laminina/genética , Masculino , Brasil/epidemiologia , Feminino , Criança , Pré-Escolar , Adolescente , Adulto , Perfil Genético , Fenótipo , Estudos Retrospectivos , Distrofias Musculares/genética , Mutação , Adulto Jovem , Predisposição Genética para Doença , Lactente , Genótipo , Pessoa de Meia-IdadeRESUMO
Prostate cancer is one of the most common neoplasm in the male population. It is not known why some tumors become more aggressive than others. Although most studies show changes in the expression of cell adhesion molecules and the extracellular matrix correlated with the Gleason score, no study has objectively measured the tissue content of these molecules. This study aims to measure the content and tissue expression of collagen type I and IV and laminin in the extracellular matrix of patients with prostate adenocarcinoma and correlate these findings with the Gleason score and clinical characteristics. Forty-one patients who underwent radical prostate surgery at the Urology Department of a reference Hospital in Brazil between January 2015 and December 2020 were studied. The tissue protein content was estimated under light microscopy at a final magnification of 200 × . The mean collagen I score in prostate adenocarcinoma tissue samples was 7.16 ± 1.03 pixels/field. The mean type IV collagen score was 3.44 ± 0.61 pixels/field. The mean laminin score was 5.19 ± 0.79 pixels/field. The total Gleason score was correlated with both collagen and laminin. All the correlations were negative, which shows that the higher the collagen/laminin expression was, the lower the total Gleason score (p-value < 0,05). According to the Pearson correlation analysis, age has no statistical relationship with collagen and laminin content. PSA, in turn, showed a correlation only with laminin, but r = -0.378 (p = 0.015). Among the associated diseases and lifestyle habits, there is only statistical significance in the comparison of alcoholism for collagen I. For collagen IV and laminin, no statistical significance was obtained with the clinical variables analyzed.
Assuntos
Adenocarcinoma , Colágeno Tipo IV , Colágeno Tipo I , Matriz Extracelular , Laminina , Gradação de Tumores , Neoplasias da Próstata , Humanos , Masculino , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Laminina/metabolismo , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Colágeno Tipo IV/metabolismo , Colágeno Tipo I/metabolismo , Matriz Extracelular/metabolismo , Idoso , Pessoa de Meia-IdadeRESUMO
Breast cancer remains a pressing public health issue primarily affecting women. Recent research has spotlighted bioactive peptides derived from laminin-111, implicated in breast tumor development. Remarkably, the sequences IKVAV, YIGSR, and KAFDITYVRLKF from the α1, ß1, and γ1 chains, respectively, have garnered significant attention. This study aims to assess the potential of these radiolabeled peptides as targeting agents for breast cancer. The three peptides were synthesized using the Fmoc strategy, purified via reversed-phase high-performance liquid chromatography (RP-HPLC), and characterized through mass spectrometry. Iodine-131 (131I) radiolabeling was performed using the chloramine T method, exhibiting high radiochemical yield and stability for [131I]I-YIKVAV and [131I]I-YIGSR. Conversely, [131I]I-KAFDITYVRLKF demonstrated low radiochemical yield and stability and was excluded from the biological studies. The lipophilicity of the compounds ranged from - 2.12 to - 1.10. Serum protein binding assay for [131I]I-YIKVAV and [131I]I-YIGSR reached â 48% and â 25%, respectively. Affinity for breast cancer cells was evaluated using MDA-MB-231 and MCF-7 tumor cell lines, indicating the affinity of the radiopeptides with these tumor cells. Ex vivo biodistribution profiles of the radiopeptides were assessed in the MDA-MB-231 breast tumor animal model, revealing tumor tissue accumulation, supported by a high tumor-to-contralateral muscle ratio and autoradiography. These results signify the effective penetration of YIKVAV and YIGSR into tumor tissue. Therefore, the synthesized α1 and ß1 peptide fragments exhibit favorable characteristics as potential breast cancer-targeting agents, promising future exploration as radiopharmaceuticals for breast cancer.
Assuntos
Neoplasias da Mama , Animais , Feminino , Humanos , Neoplasias da Mama/tratamento farmacológico , Estudos Prospectivos , Distribuição Tecidual , Peptídeos/farmacologia , LamininaRESUMO
Classical swine fever virus (CSFV) is an ancient pathogen that continues to pose a threat to animal agriculture worldwide. The virus belongs to the genus Pestivirus and the family Flaviviridae. It causes a multisystemic disease that affects only pigs and is responsible for significant economic losses. CSFV infection is probably a multistep process that involves the proteins in the virus envelope and more than one receptor in the membrane of permissive cells. To date, the cellular receptors essential for CSFV entry and their detailed functions during this process remains unknown. All the viral envelope proteins Erns, E1 and E2 are involved in the entry process to some extent and the experimental approaches conducted until now have helped to unveil their contributions. This review aims to provide an overview of current knowledge on cellular molecules described to be involved in CSFV entry, including complement regulatory protein 46 (CD46), heparan sulphate (HS), Laminin receptor, Integrin ß3, Annexin II, MERKT and ADAM17. This knowledge would not only help to understand the molecular mechanisms involved in pestivirus infection, but also provide a rational basis for the development of nonvaccinal alternatives for CSFV control.
Assuntos
Vírus da Febre Suína Clássica , Peste Suína Clássica , Doenças dos Suínos , Animais , Suínos , Vírus da Febre Suína Clássica/fisiologia , Linhagem Celular , Proteínas do Envelope Viral , Receptores de Superfície Celular/metabolismoRESUMO
Congenital muscular dystrophy type 1A (CMD1A) is a rare autosomal recessive disorder caused by mutations in the LAMA2 gene. CMD1A is characterized by peripheral hypotonia and muscle weakness from the first months of life, cerebral white matter abnormalities, and elevated creatine phosphokinase (CPK) levels. We describe an 8-year-old girl from Colombia with clinical features compatible with CMD1A, severe scoliosis corrected with surgery, and feeding difficulty corrected with a gastrostomy. Whole-exome sequencing identified two heterozygous variants: a reported nonsense variant (LAMA2 NM_000426.3:c.4198C>T) and a novel likely pathogenic variant (LAMA2 NM_000426.3:c.9227_9243dup). This is the first genetically confirmed case of CMD1A in Colombia and the first report of the c.9227_9243dup variant causing CMD1A.
RESUMO
A Distrofia muscular laminin subunit alpha 2 (DM LAMA2) é caracterizada pela deficiência da proteína da cadeia laminina α2, apresentando sintomas distróficos que progridem na infância. Objetivo: Apresentar dados da avaliação fisioterapêutica de uma criança com DM LAMA2 em acompanhamento ambulatorial. Métodos: Pesquisou-se em prontuário dados referentes às avaliações fisioterapêuticas de uma criança de 12 anos com diagnóstico de DM LAMA2 atendida em ambulatório especializado. A avaliação caracterizou-se por ausculta pulmonar, espirometria, verificação de parâmetros cardiorrespiratórios, análise do pico de fluxo de tosse (PFT), força muscular respiratória (FMR) e avaliação motora através da escala MFM-32. Resultados: Realizou-se três avaliações durante 9 meses. A paciente possui doença pulmonar restritiva, na primeira avaliação apresentou VEF1= 29% na espirometria e, comparando com a terceira avaliação obteve aumento de 1%, também houve aumento de 2% na relação VEF1/CVF, 5% no PEF e 11% no FEF25-75%. Na FMR, obteve-se valores de PImáx= 17,9% e PEmáx= 7,13% na primeira avaliação com aumento de 16,85% e 5,34% respectivamente, entre primeira e terceira avaliação. O PFT manteve-se em 0L/min em todas avaliações. Na primeira avaliação motora pontuou 25% no escore total da escala MFM-32, aumentando 3,12% na terceira avaliação. Ao longo do acompanhamento iniciou-se o uso da VNI noturna e introduzida a técnica de AS, buscando correção da hipoxemia, apneias noturnas, aumento do PFT e FMR. Conclusão: Paciente apresentou manutenção de parâmetros espirométricos, aumento de variáveis de FMR e função motora, sem piora do quadro. Possíveis resultados decorridos do acompanhamento multiprofissional e especializado.
Laminin subunit alpha 2 muscular dystrophy (DMLAMA2) is characterized by a deficiency of the α2 laminin chain protein, presenting dystrophic symptoms that progress in childhood. Objective: To present data from the physical therapy evaluation of a child with DMLAMA2 in outpatient follow-up. Methods: Medical records were searched for data referring to the physiotherapeutic evaluations of a 12-year-old child diagnosed with DMLAMA2 treated at a specialized outpatient clinic. The evaluation was characterized by pulmonary auscultation, spirometry, verification of cardiorespiratory parameters, analysis of peak cough flow (PFT), respiratory muscle strength (FMR) and motor evaluation using the MFM-32 scale. Results: Three evaluations were carried out during 9 months. The patient has restrictive disease, in the first evaluation she had FEV1= 29% in spirometry, compared to the third evaluation, she had an increase of 1%, there was also an increase of 2% in the FEV1/FVC ratio, 5% in the PEF and 11% in the FEF25-75%. In the FMR, values of MIP=17.9% and MEP= 7.13% were obtained in the first assessment, with an increase of 16.85% and 5.34%, respectively, between the first and third assessments. The PFT remained at 0L/min in all evaluations. In the first motor evaluation, it scored 25% in the total score of the MFM-32 scale, increasing 3.12% in the third evaluation. During the follow-up, the use of nocturnal NIV started and AS technique was introduced, seeking correction of hypoxemia, night apneas, increased PFT and FMR. Conclusion: Patient presented maintenance of spirometric parameters, increased FMR variables and motor function, without worsening the condition. Possible results from the multidisciplinary and specialized monitoring.
RESUMO
Laminin, a non-collagenous glycoprotein present in the brain extracellular matrix, helps to maintain blood-brain barrier (BBB) integrity and regulation. Neuroinflammation can compromise laminin structure and function, increasing BBB permeability. The aim of this paper is to determine if neuroinflammation-induced laminin functional changes may serve as a potential biomarker of alterations in the BBB. The 38 publications included evaluated neuroinflammation, BBB disruption, and laminin, and were assessed for quality and risk of bias (protocol registered in PROSPERO; CRD42020212547). We found that laminin may be a good indicator of BBB overall structural integrity, although changes in expression are dependent on the pathologic or experimental model used. In ischemic stroke, permanent vascular damage correlates with increased laminin expression (ß and γ subunits), while transient damage correlates with reduced laminin expression (α subunits). Laminin was reduced in traumatic brain injury and cerebral hemorrhage studies but increased in multiple sclerosis and status epilepticus studies. Despite these observations, there is limited knowledge about the role played by different subunits or isoforms (such as 411 or 511) of laminin in maintaining structural architecture of the BBB under neuroinflammation. Further studies may clarify this aspect and the possibility of using laminin as a biomarker in different pathologies, which have alterations in BBB function in common.
Assuntos
Barreira Hematoencefálica , Laminina , Biomarcadores/metabolismo , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Humanos , Laminina/metabolismo , Doenças NeuroinflamatóriasRESUMO
Neutrophils are recruited from the blood and transmigrate through the endothelium to reach tissues, where they are prone to respond through different mechanisms, including the release of neutrophil extracellular traps (NETs). These responses occur in close contact with proteins from the basement membrane and extracellular matrix, where laminins are abundant. Thus, we investigated the interactions between neutrophils and different laminin (LM) isoforms and analyzed the induction of NETs. We showed that neutrophils stimulated with LM isoforms 111, 211, 332, 411, 421, and 511 released NETs. The same occurred when neutrophils interacted with polymerized LMs 111, 411, and 511. LM-induced NETs were partially inhibited by pretreatment of neutrophils with an anti-α6 integrin antibody. Furthermore, NETs triggered by laminins were dependent on elastase and peptidylarginine deiminase (PAD)-4, enzymes that participate in chromatin decondensation. We also found that LMs 411 and LM 511 potentiated the NET release promoted by promastigotes of the protozoan parasite Leishmania, and that NETs stimulated by LMs alone display leishmanicidal activity. The ability of LM to induce NET release may have potential implications for the course of inflammation or infection.
RESUMO
BACKGROUND Clostridioides difficile is the most common cause of nosocomial diarrhea associated with antibiotic use. The disease's symptoms are caused by enterotoxins, but other surface adhesion factors also play a role in the pathogenesis. These adhesins will bind to components of extracellular matrix. OBJECTIVE There is a lack of knowledge on MSCRAMM, this work set-out to determine the adhesive properties of several C. difficile ribotypes (027, 133, 135, 014, 012) towards laminin-1 (LMN-1). METHODS A binding experiment revealed that different ribotypes have distinct adhesion capabilities. To identify this adhesin, an affinity chromatography column containing LMN-1 was prepared and total protein extracts were analysed using mass spectrometry. FINDINGS Strains from ribotypes 012 and 027 had the best adhesion when incubated with glucose supplementations (0.2%, 0.5%, and 1%), while RT135 had a poor adherence. The criteria were not met by RT014 and RT133. In the absence of glucose, there was no adhesion for any ribotype, implying that glucose is required and plays a significant role in adhesion. MAIN CONCLUSIONS These findings show that in the presence of glucose, each C. difficile ribotype interacts differently with LMN-1, and the adhesin responsible for recognition could be SlpA protein.