COL6A3 promotes cellular malignancy of osteosarcoma by activating the PI3K/AKT pathway

SUMMARY OBJECTIVE In this study, we aimed to investigate the role of COL6A3 on cell motility and the PI3K/AKT signaling pathway in osteosarcoma. METHODS The relative expression of COL6A3 was achieved from a GEO dataset in osteosarcoma tissue. siRNA technology was applied to decrease the COL6A3 expression in cells, and cell counting kit-8 (CCK-8) assay and colony formation analysis were used to examine the cell proliferation potential. Knockdown COL6A3 made the proliferation and colony formation abilities worse than the COL6A3 without interference. Likewise, in contrast to the si-con group, cell invasion and migration were inhibited in the si-COL6A3 group. Moreover, the western blot results suggested that the PI3K/AKT signaling pathway was manipulated by measuring the protein expression of the PI3K/AKT pathway-related markers, due to the COL6A3 inhibition. CONCLUSION COL6A3 plays a crucial role in modulating various aspects of the progression of osteosarcoma, which would provide a potentially effective treatment for osteosarcoma.

RESUMO OBJETIVO Neste estudo, investigamos a função do COL6A3 na mobilidade celular e na via PI3K/AKT em osteossarcomas. METODOLOGIA A expressão relativa do COL6A3 foi obtida a partir de dados GEO em tecidos de osteossarcoma. O RNA de interferência (siRNA) foi utilizado para reduzir a expressão do COL6A3 nas células, e o teste de contagem de células kit-8 (CCK-8) e a análise de formação de colônias foram realizados para examinar o potencial de proliferação celular. Além disso, o Transwell comprovou os efeitos do si-COL6A3 na invasão celular e migração em células de osteossarcoma. Para medir os níveis de expressão das proteínas e mRNAs, utilizamos transcriptase reversa quantitativa (qRT-PCR) e western blot. RESULTADOS O COL6A3 foi regulado nos tecidos e células do osteossarcoma quando comparado com o controle normal. A redução de COL6A3 reduziu a proliferação e a capacidades de formação de colônias em relação ao COL6A3 sem interferência. Do Mesmo modo, ao contrário do observado no grupo si-con, a invasão e migração celular foram inibidas no grupo si-COL6A3. Além disso, o resultado do western blot sugere que a via PI3K/AKT foi manipulada, medindo a expressão proteica dos marcadores relacionados à PI3K/AKT, devido à inibição do COL6A3. CONCLUSÃO O COL6A3 desempenha um papel crucial na modulação de vários aspectos da progressão do osteossarcoma, o que pode representar um possível tratamento eficaz para a doença.

Miopatías relacionadas a colágeno VI: cuando sospecharlas, cómo identificarlas: aporte de la resonancia magnética muscular / Collagen VI related myopathies: when to suspect, how to identify: the contribution of muscle magnetic resonance

Resumen: Las miopatías secundarias a mutaciones en el colágeno VI (M-COLVI) son las más frecuentes en el hemisferio norte, afectando población adulta y pediátrica. No existen datos de su prevalencia en Latinoamérica. Se caracterizan por presentar una gran variabilidad clínica, desde fenotipos severos, como la distrofia muscular congénita de Ullrich (DMCU), a intermedios y leves como la Miopatía de Bethlem (MB). Su inicio también es variable y se extiende desde el período de recién nacido hasta la vida adulta. Dada la presencia de hiperlaxitud articular, el diagnóstico diferencial se debe realizar con diversas enfermedades del tejido conectivo. El algoritmo diagnóstico clásico en muchos pacientes ha sido insuficiente para orientar el estudio genético de forma adecuada, y a partir de esto la resonancia magnética muscular ha emergido como una herramienta de gran utilidad para una mejor aproxima ción diagnóstica de ésta y otras patologías musculares. Esta revisión tiene como objetivo examinar las formas de presentación, características clínicas, estudio diagnóstico específico, diagnóstico dife rencial y manejo de una de las patologías musculares herediatarias más frecuentes, con énfasis en el aporte de la resonancia magnética muscular.

Abstract: Myopathies secondary to collagen VI mutations (COLVI-M) are the most frequent in the northern hemisphere, affecting the adult and pediatric population. There are no data on its prevalence in Latin America. They are characterized by a great clinical variability, from severe phenotypes, such as Ullrich congenital muscular dystrophy (UCMD), to intermediate and mild ones such as Bethlem myopathy (BM). Its onset is also variable and extends from the neonatal period to adulthood. Given the presence of joint hypermobility, the differential diagnosis should be made with various connective tissue diseases. The classical diagnostic algorithm in many patients has been insufficient to guide the genetic study in an adequate way, and from this the muscular magnetic resonance imaging has emerged as a very useful tool for a better diagnostic approach of this and other muscular pathologies. This ob jective of this review is to study the forms of presentation, clinical characteristics, specific diagnostic study, differential diagnosis and management of one of the most frequent hereditary muscular patho logies, with emphasis on the contribution of muscle magnetic resonance imaging.

"Target" and "Sandwich" Signs in Thigh Muscles have High Diagnostic Values for Collagen VI-related Myopathies / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Collagen VI-related myopathies are autosomal dominant and recessive hereditary myopathies, mainly including Ullrich congenital muscular dystrophy (UCMD) and Bethlem myopathy (BM). Muscle magnetic resonance imaging (MRI) has been widely used to diagnosis muscular disorders. The purpose of this study was to evaluate the diagnostic value of thigh muscles MRI for collagen VI-related myopathies.</p><p><b>METHODS</b>Eleven patients with collagen VI gene mutation-related myopathies were enrolled in this study. MRI of the thigh muscles was performed in all patients with collagen VI gene mutation-related myopathies and in 361 patients with other neuromuscular disorders (disease controls). T1-weighted images were used to assess fatty infiltration of the muscles using a modified Mercuri's scale. We assessed the sensitivity and specificity of the MRI features of collagen VI-related myopathies. The relationship between fatty infiltration of muscles and specific collagen VI gene mutations was also investigated.</p><p><b>RESULTS</b>Eleven patients with collagen VI gene mutation-related myopathies included six UCMD patients and five BM patients. There was no significant difference between UCMD and BM patients in the fatty infiltration of each thigh muscle except sartorius (P = 0.033); therefore, we combined the UCMD and BM data. Mean fatty infiltration scores were 3.1 and 3.0 in adductor magnus and gluteus maximus, while the scores were 1.3, 1.3, and 1.5 in gracilis, adductor longus, and sartorius, respectively. A "target" sign in rectus femoris (RF) was present in seven cases, and a "sandwich" sign in vastus lateralis (VL) was present in ten cases. The "target" and "sandwich" signs had sensitivities of 63.6% and 90.9% and specificities of 97.3% and 96.9% for the diagnosis of collagen VI-related myopathies, respectively. Fatty infiltration scores were 2.0-3.0 in seven patients with mutations in the triple-helical domain, and 1.0-1.5 in three of four patients with mutations in the N- or C-domain of the collagen VI genes.</p><p><b>CONCLUSIONS</b>The "target" sign in RF and "sandwich" sign in VL are common MRI features and are useful for the diagnosis of collagen VI-related myopathies. The severity of fatty infiltration of muscles may have a relationship with the mutation location of collagen VI gene.</p>

Study of a Bethlem myopathy pedigree resulted from a novel mutation of COL6A3 gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the molecular etiology for a muscular dystrophy pedigree with target region sequencing platform using hereditary myopathy capture array.</p><p><b>METHODS</b>Specific gene testing was performed based on the clinical diagnosis. Since no pathogenic mutation was found, target region sequencing with hereditary myopathy capture array combined with Sanger sequencing and bioinformatics analysis were employed in turn. PolyPhen and NCBI were used to evaluate the pathogenicity of identified mutation and conservation of the gene.</p><p><b>RESULTS</b>Target region sequencing indicated the proband has carried a heterozygous c.3353 A>C mutation of COL6A3 gene, which was confirmed by Sanger-sequencing in 4 affected individuals from the family. The same mutation was not detected in healthy members of the pedigree. Bioinformatics analysis suggested that the mutation has caused a highly pathogenic amino acid substitution from Histidine to Proline. The affected patients featured normal intelligence with mild myogenic damage by muscle biopsy, slightly increased serum creatine kinase and slow disease progression, which was consistent with Bethlem myopathy.</p><p><b>CONCLUSION</b>Target region sequencing is an effective and efficient method for genetic testing. The heterozygous c.3353A>C mutation in exon 8 of the COL6A3 gene probably underlies the Bethlem myopathy with autosomal dominant inheritance.</p>

Ullrich Congenital Muscular Dystrophy Possibly Related With COL6A1 p.Gly302Arg Variant

Ullrich congenital muscular dystrophy (UCMD) is characterized by congenital weakness, proximal joint contractures, and hyperlaxity of distal joints. UCMD is basically due to a defect in extra cellular matrix protein, collagen type VI. A 37-year-old woman who cannot walk independently visited our outpatient clinic. She had orthopedic deformities (scoliosis, joint contractures, and distal joint hyperlaxity), difficulty of respiration, and many skin keloids. Her hip computed tomography showed diffuse fatty infiltration and the 'central shadow' sign in thigh muscles. From the clinical information suggesting collagen type VI related muscle disorder, UCMD was highly considered. COL6A1 gene sequencing confirmed this patient as UCMD with novel c.904G>A (p.Gly302Arg) variant. If musculoskeletal and dermatologic manifestations and radiologic findings imply abnormalities in collagen type VI network, COL6A related congenital muscular dystrophy was to be suspected.

Distrofia muscular congênita de Ullrich moderadamente progressiva / Moderately progressive Ullrich congenital muscular dystrophy

OBJETIVOS: Descrever características clínicas e genéticas da distrofia muscular congênita de Ullrich (DMCU), e relatar o caso de um paciente diagnosticado com DMCU após uma exaustiva investigação, que incluiu análise imuno-histoquímica e genômica do colágeno tipo VI. DESCRIÇÃO: Este estudo baseou-se na avaliação clínica e imuno-histoquímica do tecido muscular e na análise genômica dos fibroblastos dérmicos de um menino de 7 anos e meio, e do DNA dos seus pais. São discutidos aspectos clínicos e o diagnóstico diferencial com outras doenças. COMENTÁRIOS: O melhor conhecimento das distrofias musculares congênitas aumentará o número de diagnósticos corretos e abrirá novos horizontes para o tratamento dessas doenças. A avaliação genética dos pacientes com DMCU tem implicações relevantes para o prognóstico e o aconselhamento genético da família. É aconselhável divulgar essa doença na comunidade pediátrica, devido ao início precoce das manifestações clínicas e o fato de ser frequentemente mal diagnosticada ou não ser diagnosticada.

OBJECTIVES: To describe genetic and clinical features of Ullrich congenital muscular dystrophy (UCMD), and to report the case of a patient diagnosed with UCMD after an exhaustive investigation, which included collagen VI immunohistochemical and genomic analyses. DESCRIPTIONS: This study was based on clinical, immunohistochemical assessment of muscle tissue and genomic analysis of dermal fibroblasts of a 7 1/2-year old boy and of the DNA of his parents. Clinical aspects and differential diagnosis with other disorders are discussed. COMMENTS: A better knowledge of congenital muscular dystrophies will improve the number of correct diagnoses and open new horizons for the treatment of such diseases. Genetic evaluation of UCMD patients has relevant implications for prognosis and genetic counseling of the family. The divulgation of this disorder in the pediatric community is advisable, because of the early onset of clinical manifestations and the fact that it is frequently misdiagnosed or not diagnosed at all.

Congenital muscular dystrophy: part I: a review of phenotypical and diagnostic aspects / Distrofia muscular congênita: parte I: revisão dos aspectos fenotípicos e diagnósticos

The congenital muscular dystrophies (CMDs) are a group of genetically and clinically heterogeneous hereditary myopathies with preferentially autosomal recessive inheritance, that are characterized by congenital hypotonia, delayed motor development and early onset of progressive muscle weakness associated with dystrophic pattern on muscle biopsy. The clinical course is broadly variable and can comprise the involvement of the brain and eyes. From 1994, a great development in the knowledge of the molecular basis has occurred and the classification of CMDs has to be continuously up dated. We initially present the main clinical and diagnostic data concerning the CMDs related to changes in the complex dystrophin-associated glycoproteins-extracellular matrix: CMD with merosin deficiency (CMD1A), collagen VI related CMDs (Ullrich CMD and Bethlem myopathy), CMDs with abnormal glycosylation of alpha-dystroglycan (Fukuyama CMD, Muscle-eye-brain disease, Walker-Warburg syndrome, CMD1C, CMD1D), and the much rarer CMD with integrin deficiency. Finally, we present other forms of CMDs not related with the dystrophin/glycoproteins/extracellular matrix complex (rigid spine syndrome, CMD1B, CMD with lamin A/C deficiency), and some apparently specific clinical forms not yet associated with a known molecular mechanism. The second part of this review concerning the pathogenesis and therapeutic perspectives of the different subtypes of CMD will be described in a next number.

As distrofias musculares congênitas (DMCs) são miopatias hereditárias geralmente, porém não exclusivamente, de herança autossômica recessiva, que apresentam grande heterogeneidade genética e clínica. São caracterizadas por hipotonia muscular congênita, atraso do desenvolvimento motor e fraqueza muscular de início precoce associada a padrão distrófico na biópsia muscular. O quadro clínico, de gravidade variável, pode também incluir anormalidades oculares e do sistema nervoso central. A partir de 1994, os conhecimentos sobre genética e biologia molecular das DMCs progrediram rapidamente, sendo a classificação continuamente atualizada. Nesta revisão apresentaremos os principais aspectos clínicos e diagnósticos dos subtipos mais comuns de DMC associados com alterações do complexo distrofina-glicoproteínas associadas-matriz extracelular que são DMC com deficiência de merosina (DMC tipo 1A), DMCs relacionadas com alterações do colágeno VI (DMC tipo Ullrich e miopatia de Bethlem), DMCs com anormalidades de gliocosilação da alfa-distroglicana (DMC Fukuyama, DMC "Muscle-eye-brain" ou MEB, síndrome de Walker-Warburg, DMC tipo 1C, DMC tipo 1D), além da raríssima DMC com deficiência de integrina. Outras formas mais raras de DMC, não relacionadas com o complexo distrofina-glicoproteínas associadas-matriz extracelular também serão apresentadas (DMC com espinha rígida, DMC tipo 1B, DMC com deficiência de lamina A/C) e, finalmente, algumas formas clínicas com fenótipo aparentemente específico que ainda não estão associadas com um defeito molecular definido. A patogenia e as perspectivas terapêuticas dos principais subtipos de DMC serão apresentados em um próximo número, na segunda parte desta revisão.

Phenotypic Characterization of Ligamentum Flavum Cells from Patients with Ossification of Ligamentum Flavum

PURPOSE: The objective of this study was to determine the phenotypic characterization of ligamentum flavum cells from patients with ossification of the ligamentum flavum (OLF). MATERIALS AND METHODS: Ligamentum flavum tissues were harvested from OLF and non-OLF patients during surgery. OLF and non-OLF cells were isolated from explant cultures. Cultured cells were analyzed using immunofluorescence staining and reverse transcription-polymerase chain reaction. RESULTS: OLF cells exhibited various appearances compared with the typical fibroblast-like morphology of non-OLF cells. Expressions of collagen type I and collagen type III were observed in OLF and non-OLF cells. OLF cells uniquely expressed osteocalcin, which is a marker for osteoblasts, and collagen type II which is a marker for chondrocytes, whereas they were negative in non-OLF cells. CONCLUSION: These findings indicate that OLF cells have phenotypic characterization of osteoblasts and chondrocytes which could play a role in the pathophysiology of OLF.

Identification of COL6A1 as a differentially expressed gene in human astrocytomas

Diffuse infiltrating gliomas are the most common tumors of the central nervous system. Gliomas are classified by the WHO according to their histopathological and clinical characteristics into four classes: grade I (pilocytic astrocytoma), grade II (diffuse astrocytoma), grade III (anaplastic astrocytoma), and grade IV (glioblastoma multiforme). Several genes have already been correlated with astrocytomas, but many others are yet to be uncovered. By analyzing the public SAGE data from 21 patients, comprising low malignant grade astrocytomas and glioblastomas, we found COL6A1 to be differentially expressed, confirming this finding by real time RT-PCR in 66 surgical samples. To the best of our knowledge, COL6A1 has never been described in gliomas. The expression of this gene has significantly different means when normal glia is compared with low-grade astrocytomas (grades I and II) and high-grade astrocytomas (grades III and IV), with a tendency to be greater in higher grade samples, thus rendering it a powerful tumor marker.

Ullrich congenital muscular dystrophy and Bethlem myopathy: clinical and genetic heterogeneity

Ullrich congenital muscular dystrophy (UCMD), due to mutations in the collagen VI genes, is an autosomal recessive form of CMD, commonly associated with distal joints hyperlaxity and severe course. A mild or moderate involvement can be occasionally observed. OBJECTIVE: To evaluate the clinical picture of CMD patients with Ullrich phenotype who presented decreased or absent collagen VI immunoreactivity on muscular biopsy. RESULTS: Among 60 patients with CMD, two had no expression of collagen V and their clinical involvement was essentially different: the first (3 years of follow-up) has mild motor difficulty; the second (8 years of follow-up) never acquired walking and depends on ventilatory support. A molecular study, performed by Pan et al. at the Thomas Jefferson University, demonstrated in the first a known mutation of Bethlem myopathy in COL6A1 and in the second the first dominantly acting mutation in UCMD and the first in COL6A1, previously associated only to Bethlem myopathy, with benign course and dominant inheritance. CONCLUSION: Bethlem myopathy should be considered in the differential diagnosis of UCMD, even in patients without fingers contractures; overlap between Ullrich and Bethlem phenotypes can be supposed.

A distrofia muscular congênita (DMC) com hiperextensibilidade articular distal (fenótipo Ullrich) associa-se a mutações nos genes do colágeno VI e corresponde a um grave quadro congênito de herança autossômica recessiva e curso progressivo, ocasionalmente mostrando menor gravidade. OBJETIVO: Avaliar o quadro clínico dos pacientes com DMC tipo Ullrich que apresentam imunoexpressão baixa ou ausente do colágeno VI na biópsia muscular. RESULTADOS: Entre 60 pacientes com DMC, dois mostravam imunomarcação negativa do colágeno VI. Mostravam-se clinicamente essencialmente diferentes: o primeiro, com 8 anos de idade e três de seguimento mostra leve dificuldade motora; o segundo, com 14 anos de idade e 8 de seguimento, não deambula e apresenta insuficiência respiratória. O estudo molecular, realizado na Thomas Jefferson University por Pan et al., revelou no primeiro, no gene COL6A1, mutação típica da miopatia de Bethlem, que tem curso benigno e herança autossômica dominante; e no segundo a primeira mutação de efeito dominante e do gene COL6A1, previamente associado apenas à miopatia de Bethlem. CONCLUSÃO: A miopatia de Bethlem deve constar no diagnóstico diferencial da DMC tipo Ullrich, mesmo na ausência das típicas contraturas dos dedos; pode existir sobreposição dos fenótipos Ullrich e Bethlem.

Análise da expressão do colágeno VI na distrofia muscular congênita / Analysis of the expression of collagen VI in congenital muscular dystrophy

A distrofia muscular congênita (DMC) compõe um grupo de miopatias caracterizadas por hipotonia e fraqueza muscular notadas já no primeiro ano de vida. A forma de Ullrich é caracterizada por retrações musculares proximais e hiperextensibilidade distal. Cerca de 40 por cento destes pacientes apresentam mutações em um dos genes que codificam as três sub-unidades do colágeno VI (COL6), acarretando deficiência total ou parcial na marcação da proteína. Analisamos, através de imunofluorescência, a marcação do COL6 em fragmentos musculares de 50 pacientes com DMC, 20 deles com ausência da marcação para merosina. Identificamos 4 casos com deficiência total da marcação do COL6 (8 por cento do total), representando 13 por cento dos casos com marcação normal para merosina. As alterações histológicas musculares dos pacientes com COL6 deficiente eram indistinguíveis das outras formas de DMC, porém mais brandas que as observadas na DMC com deficiência de merosina. Em três dos pacientes com COL6 deficiente observou-se hipotonia e fraqueza muscular, notadas já no período neonatal, atraso do desenvolvimento motor, retrações musculares em joelhos e cotovelos, hiperextensibilidade distal e luxação congênita do quadril (dois pacientes). Um paciente perdeu a capacidade para a marcha, e outro faleceu por problemas respiratórios. A análise da marcação do COL6, assim como da merosina, no tecido muscular de pacientes com DMC pode auxiliar na identificação e caracterização fenotípica dos diversos subtipos de DMC.

Alteration in Extracellular Matrix Components in Preeclamptic Nephropathy

The preeclamptic nephropathy is characterized by swelling of endothelial cells, interposition of mesangial cells and matrix, subendothelial deposits of incompletely defined material, and thickening of the capillary walls. To determine the distribution of extracellular matrix (ECM) components in preeclamptic nephropathy, the immunohistochemical study was performed in ten renal biopsy cases using antisera to human type I, III, IV, and VI collagens, fibronectin, and laminin. In preeclamptic nephropathy, the accumulation of type IV and VI collagens, fibronectin was observed in moderate amount in the mesangium and, to some extent, in the thickened capillary walls, particularly in the subendothelial layer. In segmentally sclerotic lesions seen in six cases, the amount of type IV collagen was partly decreased, whereas those of type VI collagen and fibronectin were slightly increased. Type I collagen was expressed to a mild degree in the expanded mesangium and segmentally sclerotic lesions. The results suggest that the expression of ECM in the mesangium is increased in preeclamptic nephropathy, and the deposition of ECM components may be involved in the development and the reparative process of the characteristic glomerular lesions. The formation of sclerotic lesions may be linked to the alternative accumulation of ECM components.

Purification and Characterisation of Extracellular Proteinase from Trichophyton rubrum / 대한의진균학회지

BACKGROUND: Trichophyton rubrum is the most common dermatophyte isolated from human and has ability to invade the tissues such as stratum comeum, nail and hair. The potential role of proteinases as virulence factors of F rMSrMm has been discussed at length. OBJECTIVE: As a first step towards assessing its virulence role, we report on the purification and characterization of proteinase from T. rubrum isolate culture filtrates. METHODS: An extracellular serine proteinase has been purified from culture filtrates of Trichophyton rubrum HP-9 by ultrafiltration, gel filtration chromatography, and affinity column chromatography. Azocoll and keratin azure were employed as the substrates of enzyme activities. Peak of proteolytic activity was analyzed by gelatin co-polymerized gel electrophoresis. RESULTS: The molecular weight of the purified enzyme was approximately exhibited to 14.0 kDa on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and molality of 14.0 kDa proteinase activity was 6.0 and 100mM, respectively. The activity was inhibited by serine proteinase inhibitor, phenylmethylsulfonyl fluoride (PMSF). The proteinase degraded gelatin, collagen type VI, and keratin from human epidermis but not hemoglobin. CONCLUSION: The 14,000 Mr extracellular serine proteinase purified from T. rubrum NP-9 culture filtrates has neutral pH optimum 6.0 and activities against gelatin, collagen type VI, and keratin.