RESUMEN

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.

Asunto(s)

Estudios de Asociación Genética , Laminina , Humanos , Laminina/genética , Masculino , Brasil/epidemiología , Femenino , Niño , Preescolar , Adolescente , Adulto , Perfil Genético , Fenotipo , Estudios Retrospectivos , Distrofias Musculares/genética , Mutación , Adulto Joven , Predisposición Genética a la Enfermedad , Lactante , Genotipo , Persona de Mediana Edad

RESUMEN

Glioblastomas (GBM) are aggressive tumors known for their heterogeneity, rapid proliferation, treatment resistance, and extensive vasculature. Angiogenesis, the formation of new vessels, involves endothelial cell (EC) migration and proliferation. Various extracellular matrix (ECM) molecules regulate EC survival, migration, and proliferation. Culturing human brain EC (HBMEC) on GBM-derived ECM revealed a decrease in EC numbers compared to controls. Through in silico analysis, we explored ECM gene expression differences between GBM and brain normal glia cells and the impact of GBM microenvironment on EC ECM transcripts. ECM molecules such as collagen alpha chains (COL4A1, COL4A2, p < 0.0001); laminin alpha (LAMA4), beta (LAMB2), and gamma (LAMC1) chains (p < 0.0005); neurocan (NCAN), brevican (BCAN) and versican (VCAN) (p < 0.0005); hyaluronan synthase (HAS) 2 and metalloprotease (MMP) 2 (p < 0.005); MMP inhibitors (TIMP1-4, p < 0.0005), transforming growth factor beta-1 (TGFB1) and integrin alpha (ITGA3/5) (p < 0.05) and beta (ITGB1, p < 0.0005) chains showed increased expression in GBM. Additionally, GBM-influenced EC exhibited elevated expression of COL5A3, COL6A1, COL22A1 and COL27A1 (p < 0.01); LAMA1, LAMB1 (p < 0.001); fibulins (FBLN1/2, p < 0.01); MMP9, HAS1, ITGA3, TGFB1, and wingless-related integration site 9B (WNT9B) (p < 0.01) compared to normal EC. Some of these molecules: COL5A1/3, COL6A1, COL22/27A1, FBLN1/2, ITGA3/5, ITGB1 and LAMA1/B1 (p < 0.01); NCAN, HAS1, MMP2/9, TIMP1/2 and TGFB1 (p < 0.05) correlated with GBM patient survival. In conclusion, this study identified both established and novel ECM molecules regulating GBM angiogenesis, suggesting NCAN and COL27A1 are new potential prognostic biomarkers for GBM.

Asunto(s)

Neoplasias Encefálicas , Matriz Extracelular , Glioblastoma , Neovascularización Patológica , Humanos , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patología , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Matriz Extracelular/metabolismo , Pronóstico , Células Endoteliales/metabolismo , Microambiente Tumoral/genética , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Regulación Neoplásica de la Expresión Génica , Laminina/metabolismo , Laminina/genética , Angiogénesis

RESUMEN

BACKGROUND: LAMA2-related muscular dystrophy is a disorder that causes muscle weakness and varies in severity, from a severe, congenital type to a milder, late-onset form. However, the disease does not only affect the muscles, but has systemic involvement and can lead to alterations such as brain malformation, epilepsy and intellectual disability. OBJECTIVE: Describe the frequency of cortical malformations, epilepsy and intellectual disability in LAMA2-RD in a Brazilian cohort and correlate the neurological findings to genetic and motor function. METHODS: This is an observational study of 52 LAMA2-RD patients, who were divided into motor function subgroups and compared based on brain MRI findings, epilepsy, intellectual disability, and type of variants and variant domains. RESULTS: 44 patients (84.6%) were only able to sit, and 8 patients (15.4%) were able to walk. 10 patients (19.2%) presented with cortical malformations (polymicrogyria, lissencephaly-pachygyria, and cobblestone),10 patients (19.2%) presented with epilepsy, and 8 (15.4%) had intellectual disability. CNS manifestations correlated with a more severe motor phenotype and none of the patients able to walk presented with cortical malformation or epilepsy. There was a relation between gene variants affecting the laminin-α2 LG-domain and the presence of brain malformation (P = 0.016). There was also a relation between the presence of null variants and central nervous system involvement. A new brazilian possible founder variant was found in 11 patients (21,15%) (c.1255del; p. Ile419Leufs*4). CONCLUSION: Cortical malformations, epilepsy and intellectual disability are more frequent among LAMA2-RD patients than previously reported and correlate with motor function severity and the presence of variants affecting the laminin-α2 LG domain. This brings more insight fore phenotype-genotype correlations, shows the importance of reviewing the brain MRI of patients with LAMA2-RD and allows greater attention to the risk of brain malformation, epilepsy, and intellectual disability in those patients with variants that affect the LG domain.

Asunto(s)

Epilepsia , Discapacidad Intelectual , Humanos , Encéfalo/diagnóstico por imagen , Epilepsia/diagnóstico por imagen , Epilepsia/genética , Genotipo , Discapacidad Intelectual/diagnóstico por imagen , Discapacidad Intelectual/genética , Laminina/genética , Imagen por Resonancia Magnética , Fenotipo

Asunto(s)

Liquen Plano Oral , Neoplasias de la Boca , Lesiones Precancerosas , Moléculas de Adhesión Celular , Transformación Celular Neoplásica , Estudios Transversales , Humanos , Laminina/genética , Liquen Plano Oral/genética , Kalinina

RESUMEN

Aim: The aim of this study was to analyze the prognostic value of integrin subunit ß1 and laminin γ1 chain in patients with cervical cancer (CC). Materials & methods: The study included 96 samples. Cytological diagnosis, human papillomavirus (HPV) genotyping, HPV integration status and integrin subunit ß1 and laminin γ1 chain expressions were performed or determined using Papanicolaou smear, INNO-LiPA® Genotyping Extra Kit, in situ hybridization, and immunocytochemistry, respectively. The association between variables was calculated using chi-squared and Fisher's exact test; logistic regression analysis was performed to calculate odds ratios and CI at 95%. Results: Our results show that integrin subunit ß1 and laminin γ1 chain expressions increase according to tumor progression. Integrin subunit ß1 and laminin γ1 chain expressions are associated with cytological diagnosis (p < 0.001 and p = 0.001, respectively) and laminin γ1 chain expression with the integration status of HPV (p < 0.001). Moderate/high expressions of integrin subunit ß1 and laminin γ1 chain were correlated with overall survival and increased risk of CC (6.86 and 3.75, respectively), the odds ratio was 12.91 when the moderate/high expression of integrin subunit ß1 and laminin γ1 chain were combined. Conclusion: Our results suggest that integrin subunit ß1 and laminin γ1 chain expressions could be a prognostic biomarker in CC.

Asunto(s)

Integrina beta1/genética , Laminina/genética , Neoplasias del Cuello Uterino/metabolismo , Adulto , Alphapapillomavirus/patogenicidad , Biomarcadores de Tumor/genética , Femenino , Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Inmunohistoquímica , Hibridación in Situ , Integrina beta1/metabolismo , Integrinas/genética , Laminina/metabolismo , México , Persona de Mediana Edad , Infecciones por Papillomavirus/genética , Pronóstico , Neoplasias del Cuello Uterino/genética

RESUMEN

Posaconazole (POS) is an inhibitor of ergosterol biosynthesis in clinical use for treating invasive fungal infections. POS has potent and selective anti-Trypanosoma cruzi activity and has been evaluated as a possible treatment for Chagas disease. Microtissues are a 3D culture system that has been shown to reproduce better tissue architecture and functionality than cell cultures in monolayer (2D). It has been used to evaluate chemotropic response as in vitro disease models. We previously developed an in vitro model that reproduces aspects of cardiac fibrosis observed in Chagas cardiomyopathy, using microtissues formed by primary cardiac cells infected by the T. cruzi, here called T. cruzi fibrotic cardiac microtissue (TCFCM). We also showed that the treatment of TCFCM with a TGF-ß pathway inhibitor reduces fibrosis. Here, we aimed to evaluate the effect of POS in TCFCM, observing parasite load and molecules involved in fibrosis. To choose the concentration of POS to be used in TCFCM we first performed experiments in a monolayer of primary cardiac cell cultures and, based on the results, TCFCM was treated with 5 nM of POS for 96 h, starting at 144 h post-infection. Our previous studies showed that at this time the TCFCM had established fibrosis, resulting from T. cruzi infection. Treatment with POS of TCFCM reduced 50 % of parasite load as observed by real-time PCR and reduced markedly the fibrosis as observed by western blot and immunofluorescence, associated with a strong reduction in the expression of fibronectin and laminin (45 % and 54 %, respectively). POS treatment also changed the expression of proteins involved in the regulation of extracellular matrix proteins (TGF-ß and TIMP-4, increased by 50 % and decreased by 58 %, respectively) in TCFCM. In conclusion, POS presented a potent trypanocidal effect both in 2D and in TCFCM, and the reduction of the parasite load was associated with a reduction of fibrosis in the absence of external immunological effectors.

Asunto(s)

Cardiomiopatía Chagásica/tratamiento farmacológico , Fibrosis Endomiocárdica/tratamiento farmacológico , Miocitos Cardíacos/efectos de los fármacos , Triazoles/farmacología , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Técnicas de Cultivo de Célula , Cardiomiopatía Chagásica/genética , Cardiomiopatía Chagásica/parasitología , Cardiomiopatía Chagásica/patología , Fibrosis Endomiocárdica/genética , Fibrosis Endomiocárdica/parasitología , Fibrosis Endomiocárdica/patología , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Feto , Fibronectinas/genética , Fibronectinas/metabolismo , Regulación de la Expresión Génica , Humanos , Concentración 50 Inhibidora , Laminina/genética , Laminina/metabolismo , Ratones , Modelos Biológicos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/parasitología , Carga de Parásitos , Cultivo Primario de Células , Inhibidores Tisulares de Metaloproteinasas/genética , Inhibidores Tisulares de Metaloproteinasas/metabolismo , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismo , Trypanosoma cruzi/crecimiento & desarrollo , Trypanosoma cruzi/patogenicidad , Inhibidor Tisular de Metaloproteinasa-4

RESUMEN

Pierson syndrome is characterized by congenital nephrotic syndrome and bilateral microcoria. Genetically, mutations in the LAMB2 gene, which encodes the laminin ß2 chain, lead to this disorder. To date, 98 cases and 50 different mutations have been reported in literature. There are no specific therapies for Pierson syndrome and treatment is supportive. The prognosis is poor because of progressive impairment of renal function and complications of renal failure. We report a novel homozygous mutation (c.1890G>T, p.Q630H) in the LAMB2 gene in a patient with Pierson syndrome who had atypical phenotypic feature such as epidermolysis bullosa.

---

El síndrome de Pierson se caracteriza por la presencia de síndrome nefrótico congénito y microcoria bilateral. Genéticamente, este trastorno está ocasionado por mutaciones en el gen LAMB2, que codifica la cadena ß2 de la laminina. Hasta la fecha, en la bibliografía se informaron 98 casos y 50 mutaciones diferentes. No existen terapias específicas para el síndrome de Pierson, y el tratamiento es complementario. El pronóstico es malo por la disfunción renal progresiva y las complicaciones de la insuficiencia renal. En este artículo, se informa sobre una mutación homocigota novedosa (c.1890G>C [p.Q630H]) en el gen LAMB2 en una paciente con síndrome de Pierson que tenía un fenotipo atípico, como epidermólisis ampollosa.

Asunto(s)

Laminina/genética , Síndromes Miasténicos Congénitos/diagnóstico , Síndrome Nefrótico/diagnóstico , Trastornos de la Pupila/diagnóstico , Femenino , Marcadores Genéticos , Homocigoto , Humanos , Lactante , Mutación , Síndromes Miasténicos Congénitos/genética , Síndrome Nefrótico/genética , Fenotipo , Trastornos de la Pupila/genética

RESUMEN

Congenital myasthenic syndromes (CMS) are heterogeneous genetic diseases in which neuromuscular transmission is compromised. CMS resembling the Lambert-Eaton myasthenic syndrome (CMS-LEMS) are emerging as a rare group of distinct presynaptic CMS that share the same electrophysiological features. They have low compound muscular action potential amplitude that increment after brief exercise (facilitation) or high-frequency repetitive nerve stimulation. Although clinical signs similar to LEMS can be present, the main hallmark is the electrophysiological findings, which are identical to autoimmune LEMS. CMS-LEMS occurs due to deficits in acetylcholine vesicle release caused by dysfunction of different components in its pathway. To date, the genes that have been associated with CMS-LEMS are AGRN, SYT2, MUNC13-1, VAMP1, and LAMA5. Clinicians should keep in mind these newest subtypes of CMS-LEMS to achieve the correct diagnosis and therapy. We believe that CMS-LEMS must be included as an important diagnostic clue to genetic investigation in the diagnostic algorithms to CMS. We briefly review the main features of CMS-LEMS.

Asunto(s)

Síndrome Miasténico de Lambert-Eaton/diagnóstico , Síndromes Miasténicos Congénitos/diagnóstico , Acetilcolina/fisiología , Agrina/genética , Autoinmunidad , Señalización del Calcio , Electrofisiología , Ejercicio Físico , Exocitosis , Humanos , Laminina/genética , Síndromes Miasténicos Congénitos/genética , Proteínas del Tejido Nervioso/genética , Conducción Nerviosa , Unión Neuromuscular/fisiopatología , Proteínas SNARE/fisiología , Transmisión Sináptica , Sinaptotagmina II/genética , Proteína 1 de Membrana Asociada a Vesículas/genética

RESUMEN

BACKGROUND: Cardiac fibrosis is a consequence of chronic chagasic cardiomyopathy (CCC). In other cardiovascular diseases, the protagonist role of fibroblasts in cardiac fibrosis is well established. However, the role of cardiac fibroblasts (CFs) in fibrosis during the CCC is not clear. Here, our aim was to investigate the effect of Trypanosoma cruzi, the etiological agent of Chagas disease on CFs activation. METHODS: Cardiac fibroblasts were purified from primary cultures of mouse embryo cardiac cells. After two passages, cells were infected with T. cruzi (Y strain) and analyzed at different times for determination of infectivity, activation and production of extracellular matrix components (fibronectin, laminin and collagen IV) by immunofluorescence and western blot. RESULTS: At second passage, cultures were enriched in CFs (95% of fibroblasts and 5% of cardiomyocytes), as revealed by presence of alpha-smooth muscle actin (α-SMA) and discoidin domain receptor 2 (DDR2) and absence of sarcomeric tropomyosin (ST) protein expression. Trypanosoma cruzi infection induced fibroblast-myofibroblast transition, with increased expression of α-SMA after 6 and 24 h post-infection (hpi). Fibronectin was increased at 6, 24 and 48 hpi, laminin was increased at 6 and 24 hpi and collagen IV was increased at 6 hpi. CONCLUSIONS: Our results showed that T. cruzi activates CFs, inducing activation and exacerbates ECM production. Furthermore, our data raise the possibility of the involvement of CFs in heart fibrosis during Chagas disease.

Asunto(s)

Proteínas de la Matriz Extracelular/genética , Fibroblastos/parasitología , Miofibroblastos/parasitología , Trypanosoma cruzi/fisiología , Animales , Western Blotting , Células Cultivadas , Cardiomiopatía Chagásica/parasitología , Cardiomiopatía Chagásica/fisiopatología , Colágeno/genética , Fibroblastos/fisiología , Fibronectinas/genética , Técnica del Anticuerpo Fluorescente , Laminina/genética , Ratones , Miofibroblastos/fisiología

RESUMEN

ß-Dystroglycan (ß-DG) is a plasma membrane protein that has ability to target to the nuclear envelope (NE) to maintain nuclear architecture. Nevertheless, mechanisms controlling ß-DG nuclear localization and the physiological consequences of a failure of trafficking are largely unknown. We show that ß-DG has a nuclear export pathway in myoblasts that depends on the recognition of a nuclear export signal located in its transmembrane domain, by CRM1. Remarkably, NES mutations forced ß-DG nuclear accumulation resulting in mislocalization and decreased levels of emerin and lamin B1 and disruption of various nuclear processes in which emerin (centrosome-nucleus linkage and ß-catenin transcriptional activity) and lamin B1 (cell cycle progression and nucleoli structure) are critically involved. In addition to nuclear export, the lifespan of nuclear ß-DG is restricted by its nuclear proteasomal degradation. Collectively our data show that control of nuclear ß-DG content by the combination of CRM1 nuclear export and nuclear proteasome pathways is physiologically relevant to preserve proper NE structure and activity.

Asunto(s)

Distroglicanos/metabolismo , Carioferinas/metabolismo , Laminina/metabolismo , Membrana Nuclear/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteolisis , Receptores Citoplasmáticos y Nucleares/metabolismo , Animales , Línea Celular , Distroglicanos/genética , Carioferinas/genética , Laminina/genética , Ratones , Membrana Nuclear/genética , Complejo de la Endopetidasa Proteasomal/genética , Receptores Citoplasmáticos y Nucleares/genética , Proteína Exportina 1

RESUMEN

Nuclear actin (N-actin) is known to participate in the regulation of gene expression. We showed previously that N-actin levels mediate the growth and quiescence of mouse epithelial cells in response to laminin-111 (LN1), a component of the mammary basement membrane (BM). We know that BM is defective in malignant cells, and we show here that it is the LN1/N-actin pathway that is aberrant in human breast cancer cells, leading to continuous growth. Photobleaching assays revealed that N-actin exit in nonmalignant cells begins as early as 30 min after LN1 treatment. LN1 attenuates the PI3K pathway leading to upregulation of exportin-6 (XPO6) activity and shuttles actin out of the nucleus. Silencing XPO6 prevents quiescence. Malignant cells are impervious to LN1 signaling. These results shed light on the crucial role of LN1 in quiescence and differentiation and how defects in the LN1/PI3K/XPO6/N-actin axis explain the loss of tissue homeostasis and growth control that contributes to malignant progression.

Asunto(s)

Actinas/metabolismo , Neoplasias de la Mama/metabolismo , Carioferinas/metabolismo , Laminina/metabolismo , Proteínas de Neoplasias/metabolismo , Transducción de Señal , Actinas/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Femenino , Humanos , Carioferinas/genética , Laminina/genética , Proteínas de Neoplasias/genética , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo

RESUMEN

PURPOSE: We investigated the effects of laminin on the fraction of cells with self-renewing capacity in the estrogen-dependent, tamoxifen-sensitive LM05-E breast cancer cell line. We also determined whether laminin affected the response to tamoxifen. MATERIALS AND METHODS: The LM05-E breast cancer cell line was used as a model for all experiments. Aldehyde dehydrogenase (ALDH) activity, clonogenic and mammosphere assays were performed to measure the effects of laminin on modulation of the stem cell subpopulation. Pluripotent gene expression was analyzed by reverse transcriptase-polymerase chain reaction. The involvement of the mitogen-activated protein kinase (MAPK)/ERK pathway was determined using specific inhibitors. The effects of laminin on the response to tamoxifenwere determined and the involvement of α6 integrin was investigated. RESULTS: We found that pretreatment with laminin leads to a decrease in cells with the ability to form mammospheres that was accompanied by a decrease in ALDH activity. Moreover, exposure of mammospheres to laminin reduced the capacity to form secondary mammospheres and decreased the expression of Sox-2, Nanog, and Oct-4. We previously reported that 4-OH-tamoxifen leads to an increase in the expression of these genes in LM05-E cells. Treatment with signaling pathway inhibitors revealed that the MAPK/ERK pathway mediates the effects of laminin. Finally, laminin induced tamoxifen resistance in LM05-E cells through α6 integrin. CONCLUSION: Our results suggest that the final number of cells with self-renewing capacity in estrogen-dependent breast tumors may result from the combined effects of endocrine treatment and microenvironmental cues.

Asunto(s)

Laminina/metabolismo , Sistema de Señalización de MAP Quinasas , Células Madre Neoplásicas/metabolismo , Animales , Biomarcadores , Diferenciación Celular , Línea Celular Tumoral , Autorrenovación de las Células , Resistencia a Antineoplásicos/genética , Laminina/genética , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Neoplasias Mamarias Experimentales , Ratones , Células Madre Neoplásicas/patología , Tamoxifeno/farmacología , Células Tumorales Cultivadas , Ensayo de Tumor de Célula Madre

RESUMEN

The aim of this study was to detect the anti-fibrosis activity of connective tissue growth factor (CTGF) small hairpin RNA (shRNA) mediated by polyamidoamine dendrimer nanoparticles in rat myocardial cell lines and myocardium. CTGF shRNAs were constructed from inverted oligonucleotides and a polyamidoamine nanoparticle vector was used to transfer shRNA into H9c2 myocardial cells and spontaneously hypertensive rats. The expression of CTGF, transforming growth factor-b1, and laminin were measured by semi-quantitative reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry. pCTGF-shRNA significantly reduced CTGF upregulation induced by angiotensin II in H9c2 myocardial cells. The mRNA and protein expression of CTGF and laminin in pCTGF-shRNA-transferred spontaneously hypertensive rats decreased significantly compared to the control group and pHK-shRNA group (P < 0.05). The expression of transforming growth factor-b1 showed no significant difference among the 3 groups (P > 0.05). pCTGF-shRNA mediated by polyamidoamine can be used to successfully reduce myocardial CTGF and laminin expression, suggesting that this system can be used to improve myocardial fibrosis therapy.

Asunto(s)

Factor de Crecimiento del Tejido Conjuntivo/genética , Nanopartículas/administración & dosificación , Interferencia de ARN , ARN Interferente Pequeño/administración & dosificación , Animales , Western Blotting , Línea Celular , Factor de Crecimiento del Tejido Conjuntivo/metabolismo , Dendrímeros/química , Expresión Génica , Inmunohistoquímica , Laminina/genética , Laminina/metabolismo , Masculino , Miocardio/citología , Miocardio/metabolismo , Nanopartículas/química , Poliaminas/química , ARN Interferente Pequeño/química , ARN Interferente Pequeño/genética , Ratas Endogámicas SHR , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismo

RESUMEN

Segmental uniparental isodisomy (iUPD) is a rare genetic event that may cause aberrant expression of imprinted genes, and reduction to homozygosity of a recessive mutation. Transient neonatal diabetes mellitus (TNDM) is typically caused by imprinting aberrations in chromosome 6q24 TNDM differentially-methylated region (DMR). Approximately, 15.12 Mb upstream in 6q22-q23 is located LAMA2, the gene responsible of merosin-deficient congenital muscular dystrophy type 1A (MDC1A). We investigated a patient diagnosed both with TNDM and MDC1A, born from a twin dichorionic discordant pregnancy. Parents are first-degree cousins. Methylation sensitive-PCR of the imprinted 6q24 TNDM CpG island showed only the non-methylated (paternal) allele. Microsatellite markers and SNP array profiling disclosed normal biparental inheritance at 6p and a segmental paternal iUPD, between 6q22.33 and 6q27. Sequencing of LAMA2 exons showed a homozygous frameshift mutation, c.7490_7493dupAAGA, which predicts p.Asp2498GlufsX4, in exon 54. Her father, but not her mother, was a carrier of the mutation. While segmental paternal iUPD6 causing TNDM was reported twice, there are no previous reports of MDC1A caused by this event. This is a child with two genetic disorders, yet neither is caused by the parental consanguinity, which reinforces the importance of considering different etiological mechanisms in the genetic clinic.

Asunto(s)

Cromosomas Humanos Par 6 , Diabetes Mellitus/genética , Distrofias Musculares/diagnóstico , Distrofias Musculares/genética , Disomía Uniparental , Adulto , Islas de CpG , Metilación de ADN , Análisis Mutacional de ADN , Femenino , Impresión Genómica , Genotipo , Humanos , Lactante , Laminina/genética , Masculino , Repeticiones de Microsatélite , Mutación , Fenotipo , Polimorfismo de Nucleótido Simple

RESUMEN

Studies on the low-abundance transcriptome are of paramount importance for identifying the intimate mechanisms of tumor progression that can lead to novel therapies. The aim of the present study was to identify novel markers and targetable genes and pathways in advanced human gastric cancer through analyses of the low-abundance transcriptome. The procedure involved an initial subtractive hybridization step, followed by global gene expression analysis using microarrays. We observed profound differences, both at the single gene and gene ontology levels, between the low-abundance transcriptome and the whole transcriptome. Analysis of the low-abundance transcriptome led to the identification and validation by tissue microarrays of novel biomarkers, such as LAMA3 and TTN; moreover, we identified cancer type-specific intracellular pathways and targetable genes, such as IRS2, IL17, IFNγ, VEGF-C, WISP1, FZD5 and CTBP1 that were not detectable by whole transcriptome analyses. We also demonstrated that knocking down the expression of CTBP1 sensitized gastric cancer cells to mainstay chemotherapeutic drugs. We conclude that the analysis of the low-abundance transcriptome provides useful insights into the molecular basis and treatment of cancer.

Asunto(s)

Adenocarcinoma/genética , Biomarcadores de Tumor/genética , Mucosa Gástrica/metabolismo , Perfilación de la Expresión Génica , Neoplasias Gástricas/genética , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/patología , Oxidorreductasas de Alcohol/antagonistas & inhibidores , Oxidorreductasas de Alcohol/genética , Oxidorreductasas de Alcohol/metabolismo , Antineoplásicos/farmacología , Biomarcadores de Tumor/metabolismo , Western Blotting , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Conectina/genética , Conectina/metabolismo , Proteínas de Unión al ADN/antagonistas & inhibidores , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Humanos , Técnicas para Inmunoenzimas , Laminina/genética , Laminina/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , ARN Interferente Pequeño/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/patología , Técnica de Sustracción , Análisis de Matrices Tisulares , Células Tumorales Cultivadas

RESUMEN

Primary deficiency of laminin alpha-2 due to mutations in the LAMA2 gene accounts for 30% of all patients with congenital muscular dystrophy. Here, we present seven patients with partial or total laminin alpha-2 deficiency (MDC1A) with a wide clinical spectrum, ranging from ambulant patients to patients who were never able to stand or sit. We identified two pathogenic mutations in the LAMA2 gene in all patients except for one patient in whom only one mutation was found. Six of the mutations were previously undescribed. In some of the milder cases, laminin alpha-2 expression in the muscle biopsy was only slightly reduced. These findings emphasize that analysis of the LAMA2 gene might be necessary in patients with muscle weakness, cerebral white matter changes and high creatine kinase levels, even in the presence of laminin alpha-2 in the muscle biopsy.

Asunto(s)

Laminina/genética , Distrofias Musculares/congénito , Distrofias Musculares/patología , Distrofias Musculares/fisiopatología , Adolescente , Adulto , Niño , Creatina Quinasa/metabolismo , Femenino , Estudios de Asociación Genética , Variación Genética , Humanos , Lactante , Laminina/deficiencia , Masculino , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Distrofias Musculares/genética , Mutación , Polimorfismo de Nucleótido Simple , Sustancia Blanca/patología , Adulto Joven

RESUMEN

From the clinical and genetic point of view, congenital muscular dystrophies (CMD) are a heterogenic group of diseases within neuromuscular pathologies. The best known forms are: merosin deficiency CMD, collagen VI deficiency CMD, LMNA-related CMD, selenoprotein-related CMD (SEPN1) and alpha-dystroglycan-related CMD. They present with a broad spectrum of clinical phenotypes. Most of them are transmitted by recessive autosomal inheritance. The initial manifestations very often begin in infancy or in the neonatal period. There are clinical suspicions of the existence of hypotonia and paresis, and they are characterised by a dystrophic pattern in the muscular biopsy (muscle replaced by fibroadipose tissue, with necrosis and cell regeneration). Advances in the understanding of the molecular pathogenesis of CMD have made it possible to make further progress in the classification of the different subtypes. The aim of this review is to comment on the advances made in recent years as regards the classification of CMD in terms of genetics, the proteins involved and their clinical presentation.

---

TITLE: Distrofias musculares congenitas en el niño.Las distrofias musculares congenitas (DMC) representan desde el punto de vista clinico y genetico un grupo heterogeneo de enfermedades dentro de la patologia neuromuscular. Las formas mas conocidas son: DMC por deficit de merosina, DMC por deficit de colageno VI, DMC relacionada con LMNA, DMC relacionada con selenoproteina (SEPN1) y las DMC vinculadas a los alfa-distroglicanos. Se presentan con un amplio espectro de fenotipos clinicos. En su mayoria son de herencia autosomica recesiva. Con mucha frecuencia las manifestaciones iniciales comienzan en la infancia o en el periodo neonatal. Se sospechan clinicamente por la existencia de hipotonia y paresia y se caracterizan por la existencia de un patron distrofico en la biopsia muscular (sustitucion de musculo por tejido fibroadiposo, con necrosis y regeneracion celular). Avances en la comprension de la patogenesis molecular de las DMC han permitido profundizar en la clasificacion de los diferentes subtipos. El objetivo de esta revision es comentar los avances de los ultimos años en cuanto a la clasificacion de las DMC en relacion a la genetica, las proteinas involucradas y su presentacion clinica.

Asunto(s)

Distrofias Musculares/congénito , Niño , Colágeno Tipo VI/deficiencia , Colágeno Tipo VI/genética , Distroglicanos/deficiencia , Distroglicanos/genética , Genotipo , Humanos , Lamina Tipo A/deficiencia , Lamina Tipo A/genética , Laminina/deficiencia , Laminina/genética , Proteínas Musculares/deficiencia , Proteínas Musculares/genética , Distrofias Musculares/clasificación , Distrofias Musculares/genética , Distrofias Musculares/terapia , Selenoproteínas/deficiencia , Selenoproteínas/genética

RESUMEN

The combination of cell therapy with growth factors could be a useful approach to treat progressive muscular dystrophies. Here, we demonstrate, for the first time, that IGF-1 considerably enhances the myogenesis of human umbilical cord (UC) mesenchymal stromal cells (MSCs) in vitro and that IGF-1 enhances interaction and restoration of dystrophin expression in co-cultures of MSCs and muscle cells from Duchenne patients. In vivo studies showed that human MSCs were able to reach the skeletal muscle of LAMA2(dy/2j) dystrophic mice, through systemic delivery, without immunosuppression. Moreover, we showed, for the first time, that IGF-1 injected systemically together with MSCs markedly reduced muscle inflammation and fibrosis, and significantly improved muscle strength in dystrophic mice. Our results suggest that a combined treatment with IGF-1 and MSCs enhances efficiency of muscle repair and, therefore, should be further considered as a potential therapeutic approach in muscular dystrophies.

Asunto(s)

Factor I del Crecimiento Similar a la Insulina/farmacología , Laminina/metabolismo , Trasplante de Células Madre Mesenquimatosas , Desarrollo de Músculos/efectos de los fármacos , Distrofia Muscular Animal/terapia , Animales , Diferenciación Celular/efectos de los fármacos , Tratamiento Basado en Trasplante de Células y Tejidos , Células Cultivadas , Técnicas de Cocultivo , Distrofina/biosíntesis , Fibrosis/terapia , Humanos , Inflamación/terapia , Laminina/genética , Células Madre Mesenquimatosas , Ratones , Células Musculares/citología , Células Musculares/metabolismo , Fuerza Muscular/efectos de los fármacos , Músculo Esquelético/citología , Músculo Esquelético/metabolismo , Cordón Umbilical/citología

RESUMEN

BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of antibodies. SLE has been associated with placental pathology, a finding that is also the determinant in preeclampsia (PE). Genetic evidence and serologic reports suggest laminin-1 (LM-111) as an immunogenic molecule and its polymorphic gene as a candidate gene for both disorders. OBJECTIVE: To evaluate the association between LAMA1 (rs543355) and LAMC1 (rs20563) polymorphisms and the presence of SLE and PE as well as to determine serum levels of anti-LM-111 autoantibodies in the PE group. METHODS: Group A: 169 women with PE and 172 healthy pregnant women. Group B: 204 women with SLE and 204 healthy women. Anti-LM-111 for group A was measured by ELISA and the genotyping was done by using a PCR system. RESULTS: Group A: Levels of anti-LM-111 was similar in women with PE and the control group (p = 0.3). The allelic frequencies and genotypes did not show statistically significant differences for LAMA1 and LAMC1 polymorphisms. Group B: Significant differences between SLE patients and controls for rs543355 polymorphism were not observed. Nevertheless, LAMC1 rs20563 A-allele provided protection against the development of SLE (OR 0.73, 95%CI 0.55-0.96). CONCLUSIONS: Serum levels of anti-LM-111 at the third trimester of gestation do not seem to have any direct relationship with the presence of PE, and the SNPs evaluated are not associated with the risk of developing this disorder. LAMC1 polymorphism could be a protective factor for SLE.

Asunto(s)

Autoanticuerpos/inmunología , Laminina/inmunología , Lupus Eritematoso Sistémico/inmunología , Preeclampsia/inmunología , Autoanticuerpos/sangre , Estudios de Casos y Controles , ADN/química , ADN/genética , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Laminina/genética , Modelos Logísticos , Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/orina , Análisis Multivariante , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido Simple/inmunología , Preeclampsia/sangre , Preeclampsia/genética , Preeclampsia/orina , Embarazo , Adulto Joven

RESUMEN

Prions, the agents of transmissible spongiform encephalopathies, require the expression of prion protein (PrP(C)) to propagate disease. PrP(C) is converted into an abnormal insoluble form, PrP(Sc), that gains neurotoxic activity. Conversely, clinical manifestations of prion disease may occur either before or in the absence of PrP(Sc) deposits, but the loss of normal PrP(C) function contribution for the etiology of these diseases is still debatable. Prion disease-associated mutations in PrP(C) represent one of the best models to understand the impact of PrP(C) loss-of-function. PrP(C) associates with various molecules and, in particular, the interaction of PrP(C) with laminin (Ln) modulates neuronal plasticity and memory formation. To assess the functional alterations associated with PrP(C) mutations, wild-type and mutated PrP(C) proteins were expressed in a neural cell line derived from a PrP(C)-null mouse. Treatment with the laminin γ1 chain peptide (Ln γ1), which mimics the Ln binding site for PrP(C), increased intracellular calcium in cells expressing wild-type PrP(C), whereas a significantly lower response was observed in cells expressing mutated PrP(C) molecules. The Ln γ1 did not promote process outgrowth or protect against staurosporine-induced cell death in cells expressing mutated PrP(C) molecules in contrast to cells expressing wild-type PrP(C). The co-expression of wild-type PrP(C) with mutated PrP(C) molecules was able to rescue the Ln protective effects, indicating the lack of negative dominance of PrP(C) mutated molecules. These results indicate that PrP(C) mutations impair process outgrowth and survival mediated by Ln γ1 peptide in neural cells, which may contribute to the pathogenesis of genetic prion diseases.

Asunto(s)

Laminina/metabolismo , Proteínas PrPC/metabolismo , Animales , Sitios de Unión , Línea Celular , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Inhibidores Enzimáticos/farmacología , Enfermedades Genéticas Congénitas/genética , Enfermedades Genéticas Congénitas/metabolismo , Laminina/genética , Ratones , Ratones Mutantes , Mutación , Proteínas PrPC/genética , Enfermedades por Prión/genética , Enfermedades por Prión/metabolismo , Estaurosporina/farmacología