Research Progress on the Role of Laminin Subunit Alpha 4 in Diseases / 中国医学科学院学报

Laminin subunit alpha 4 (LAMA4),a member of the laminin family,is present in the intercellular matrix of adult tissues as a major component of basement membrane.LAMA4 is involved in the adhesion of cells and can bind to corresponding integrins to activate relevant signaling pathways,playing an essential role in the growth,proliferation,and migration of cells.It has been demonstrated that LAMA4 is associated with the occurrence and development of a variety of diseases including tumors,and the expression of LAMA4 can be used as a biomarker of tumor diagnosis and prognosis.This paper summarizes the current research progress in LAMA4 with the focus on the relationship between LAMA4 and diseases,especially tumor,with a view to provide new directions for the future research.

A difficult airway approach in a merosin-deficient congenital muscular dystrophy patient: a case report

Abstract Merosin-deficient muscular dystrophy is caused by an autosomal recessive mutation on laminin-α2 gene characterized by severe progressive muscle weakness associated with neuromuscular scoliosis and restrictive lung disease. In this case report, we describe an alternative airway approach performed in a child with anticipated difficult airway and merosin-deficient muscular dystrophy. Significant anesthetic implications may increase the perioperative risk, requiring accurate knowledge to anticipate an adequate management and provide patient-safety strategies.

Microenvironmental stiffness mediates cytoskeleton re-organization in chondrocytes through laminin-FAK mechanotransduction / 国际口腔科学杂志·英文版

Microenvironmental biophysical factors play a fundamental role in controlling cell behaviors including cell morphology, proliferation, adhesion and differentiation, and even determining the cell fate. Cells are able to actively sense the surrounding mechanical microenvironment and change their cellular morphology to adapt to it. Although cell morphological changes have been considered to be the first and most important step in the interaction between cells and their mechanical microenvironment, their regulatory network is not completely clear. In the current study, we generated silicon-based elastomer polydimethylsiloxane (PDMS) substrates with stiff (15:1, PDMS elastomer vs. curing agent) and soft (45:1) stiffnesses, which showed the Young's moduli of ~450 kPa and 46 kPa, respectively, and elucidated a new path in cytoskeleton re-organization in chondrocytes in response to changed substrate stiffnesses by characterizing the axis shift from the secreted extracellular protein laminin β1, focal adhesion complex protein FAK to microfilament bundling. We first showed the cellular cytoskeleton changes in chondrocytes by characterizing the cell spreading area and cellular synapses. We then found the changes of secreted extracellular linkage protein, laminin β1, and focal adhesion complex protein, FAK, in chondrocytes in response to different substrate stiffnesses. These two proteins were shown to be directly interacted by Co-IP and colocalization. We next showed that impact of FAK on the cytoskeleton organization by showing the changes of microfilament bundles and found the potential intermediate regulators. Taking together, this modulation axis of laminin β1-FAK-microfilament could enlarge our understanding about the interdependence among mechanosensing, mechanotransduction, and cytoskeleton re-organization.

Bioactivity effects of extracellular matrix proteins on apical papilla cells

Abstract Potent signaling agents stimulate and guide pulp tissue regeneration, especially in endodontic treatment of teeth with incomplete root formation. Objective This study evaluated the bioactive properties of low concentrations of extracellular matrix proteins on human apical papilla cells (hAPCs). Methodology Different concentrations (1, 5, and 10 µg/mL) of fibronectin (FN), laminin (LM), and type I collagen (COL) were applied to the bottom of non-treated wells of sterilized 96-well plates. Non-treated and pre-treated wells were used as negative (NC) and positive (PC) controls. After seeding the hAPCs (5×103 cells/well) on the different substrates, we assessed the following parameters: adhesion, proliferation, spreading, total collagen/type I collagen synthesis and gene expression (ITGA5, ITGAV, COL1A1, COL3A1) (ANOVA/Tukey; α=0.05). Results We observed greater attachment potential for cells on the FN substrate, with the effect depending on concentration. Concentrations of 5 and 10 µg/mL of FN yielded the highest cell proliferation, spreading and collagen synthesis values with 10 µg/mL concentration increasing the ITGA5, ITGAV, and COL1A1 expression compared with PC. LM (5 and 10 µg/mL) showed higher bioactivity values than NC, but those were lower than PC, and COL showed no bioactivity at all. Conclusion We conclude that FN at 10 µg/mL concentration exerted the most intense bioactive effects on hAPCs.

Effects of ultrasound and stretching on skeletal muscle contusion in rats: immunohistochemistry analysis / Efectos de ultrasonido y estiramiento en la contusión muscular esqueletal en ratas: análisis inmunohistoquímico

SUMMARY: The aim of this study was to evaluate the effects of stretching and therapeutic ultrasound (TUS) on desmin and laminin contents of rat muscle after contusion. Male Wistar rats (n = 35, 8-9 weeks of age, 271 ± 14g body weight) were divided into five groups: Control group (CG) (n= 03); Injured group (IG) (n= 8); Injured + ultrasound group (IUSG) (n= 8); Injured+stretching group (ISG) (n= 8); Injured +ultrasound + stretching group (IUSSG) (n= 8). The application of ultrasound started 72 hours after the contusion, using the 50 % pulsed mode, 0.5 W/cm2, 5 min, once a day, for five consecutive days. Passive manual stretching was started on the tenth day after injury, with four repetitions of 30 s each and 30 s rest between repetitions, once a day, five times per week, for a total of ten applications. After 22 days, the rats were euthanazied and the gastrocnemius of both limbs removed for desmin and laminin immunohistochemistry morphometric measurement. Analysis was conducted using ANOVA one way post-hoc Tukey to parametric data and Kruskall-Wallis for non-parametric data. The IUSSG animals showed a larger area of desmin than ISG (p<0.05). It was found a decrease in laminin comparing IUSG to IG. However, laminin area was higher in ISG than all groups (p<0.05). UST isolated or in combination with stretching influenced gastrocnemius regeneration in different manners. While stretching applied isolated enhanced gastrocnemius regeneration noticed by the increase in laminin area, in combination with TUS strengthened the muscle healing rising desmin area.

RESUMEN: El objetivo de este estudio fue evaluar los efectos del estiramiento y la ecografía en los contenidos de desmina y laminina del músculo de rata después de la lesión. Ratas Wistar macho (n = 35, 8-9 semanas de edad, 271 ± 14 g de peso corporal) se dividieron en cinco grupos: grupo de control (CG) (n = 03); Grupo lesionado (GL) (n = 8); Lesionado + grupo de ultrasonido (LGU) (n= 8); Lesionado + grupo de estiramiento (LGE) (n = 8); Lesionado + ultrasonido + grupo de estiramiento (LUGE) (n = 8). La aplicación de ultrasonido comenzó 72 horas después de la lesión, usando el modo pulsado al 50 %, 0,5W / cm2, 5 min, una vez al día, durante cinco días consecutivos. El estiramiento manual pasivo se inició el décimo día después de la lesión, con cuatro repeticiones de 30 seg cada una y 30 seg de descanso entre repeticiones, una vez al día, cinco veces por semana, para un total de diez aplicaciones. Las ratas fueron sacrificadas después de 22 días, y se extrajo el músculo gastrocnemio de ambos miembros para la medición morfométrica de desmina y laminina a través de inmunohistoquímica. El análisis se realizó utilizando ANOVA unidireccional Tukey post-hoc para datos paramétricos y Kruskall-Wallis para datos no paramétricos. Los animales LUGE mostraron un área mayor de desmina que LGE (p <0,05). Se encontró una disminución en la laminina comparando LGU con GL. Sin embargo, el área de laminina fue mayor en LGE que en todos los grupos (p <0,05). El tratamiento con ultrasonido aislado o en combinación con estiramiento influyó en la regeneración del músculo gastrocnemio de diferentes maneras. Si bien el estiramiento aplicado, en combinación con tratamiento de ultrasonido, fortaleció el área de desmina, la regeneración del músculo gastrocnemio mejoró por el aumento en el área de laminina aumentando la curación muscular.

Ameloblastoma cell lines derived from different subtypes demonstrate distinct developmental patterns in a novel animal experimental model

Abstract Objective Ameloblastoma is a representative odontogenic tumor comprising several characteristic invasive forms, and its pathophysiology has not been sufficiently elucidated. A stable animal experimental model using immortalized cell lines is crucial to explain the factors causing differences among the subtypes of ameloblastoma, but this model has not yet been disclosed. In this study, a novel animal experimental model has been established, using immortalized human ameloblastoma-derived cell lines. Methodology Ameloblastoma cells suspended in Matrigel were subcutaneously transplanted into the heads of immunodeficient mice. Two immortalized human ameloblastoma cell lines were used: AM-1 cells derived from the plexiform type and AM-3 cells derived from the follicular type. The tissues were evaluated histologically 30, 60, and 90 days after transplantation. Results Tumor masses formed in all transplanted mice. In addition, the tumors formed in each group transplanted with different ameloblastoma cells were histologically distinct: the tumors in the group transplanted with AM-1 cells were similar to the plexiform type, and those in the group transplanted with AM-3-cells were similar to the follicular type. Conclusions A novel, stable animal experimental model of ameloblastoma was established using two cell lines derived from different subtypes of the tumor. This model can help clarify its pathophysiology and hasten the development of new ameloblastoma treatment strategies.

LAMC1 is a prognostic factor and a potential therapeutic target in endometrial cancer / 부인종양

OBJECTIVE: With the emerging significance of genetic profiles in the management of endometrial cancer, the identification of tumor-driving genes with prognostic value is a pressing need. The LAMC1 gene, encoding the laminin subunit gamma 1 (LAMC1) protein, has been reported to be involved in the progression of various malignant tumors. In this study, we aimed to investigate the role of LAMC1 in endometrial cancer and elucidate the underlying mechanism.METHODS: We evaluated the immunohistochemical expression of LAMC1 in atypical endometrial hyperplasia and endometrial cancer. Within the endometrial cancer cases, we analyzed the association of LAMC1 overexpression with clinicopathological factors and prognosis. Furthermore, to indentify genes influenced by LAMC1 overexpression, we transfected HEC50B and SPAC-S cells with siRNA targeting LAMC1 and conducted microarray gene expression assays.RESULTS: While none of the atypical endometrial hyperplasia specimens exhibited LAMC1 overexpression, endometrial cancer possessed a significantly higher LAMC1 overexpression rate. LAMC1 overexpression was strongly associated with histological type, lymphovascular space invasion, lymph node metastasis, advanced International Federation of Gynecology and Obstetrics stage, and poor overall survival in endometrial cancer. Gene expression microarray analysis identified 8 genes correlated with tumor progression (LZTFL1, TAPT1, SEL1L, PAQR6, NME7, TMEM109, CCDC58, and ANKRD40) that were commonly influenced in HEC50B and SPAC-S by LAMC1 silencing.CONCLUSION: LAMC1 overexpression is a potent biomarker for identifying endometrial cancer patients needing aggressive adjuvant therapy. We elucidated 8 candidate genes that may mediate progression of LAMC1 overexpressing cancer. Further investigation of the underlying mechanism should lead to the discovery of new therapeutic targets.

Clinical features and LAMA2 mutations of patients with congenital muscular dystrophy type 1A: a case report and literature review / 中国当代儿科杂志

Biallelic pathogenic mutations of the LAMA2 gene result in congenital muscular dystrophy type 1A (CMD1A). The patient in this study was a boy aged 19 months, with the clinical manifestations of motor development delay and increases in the serum levels of creatine kinase, aminotransferases, and lactate dehydrogenase. Genetic analysis showed that the patient had compound heterozygous mutations in the LAMA2 gene, among which c.7147C>T (p.Ala2383Ter) from his mother was a known nonsense mutation, and c.8551_8552insAA (p.Ile2852ArgfsTer2) from his father was a frameshift mutation which had never been reported before and was identified as a pathogenic mutation based on the ACMG guideline. The boy was confirmed with CMD1A. A literature review of related articles in China and overseas revealed that most children with CMD1A have disease onset within 6 months after birth, with the features of motor developmental delay, elevated serum creatine kinase, and white matter impairment on imaging examination. The mutations of the LAMA2 gene have remarkable heterogeneity, the majority of which are null mutations. There are no specific treatment methods for CMD1A currently, and children with CMD1A usually have a poor long-term prognosis.

Adipose-Derived Stem Cell Coculturing Stimulates Integrin-Mediated Extracellular Matrix Adhesion of Melanocytes by Upregulating Growth Factors

Coculture with adipose-derived stem cells (ADSCs) can stimulate proliferation and migration of melanocytes. To enhance outcomes of skin disorders caused by melanocyte loss or death, mixed transplantation with ADSCs has been suggested. However, role of cocultured ADSCs in proliferation and migration of melanocytes remains unclear. This study determined the effect of ADSCs on production of growth factors and expression levels of intergrins in primary culture of adult human melanocytes with or without ADSCs and in nude mice grafted with such melanocytes. Higher amounts of growth factors for melanocytes, such as bFGF and SCF were produced and released from ADSCs by coculturing with melanocytes. Relative levels of integrins β1, α5, and α6 as well as adhesion to fibronectin and laminin were increased in melanocytes cocultured with ADSCs. Such increases were inhibited by neutralization of bFGF or SCF. Relative levels of bFGF, SCF and integrins were increased in nude mice skin after grafting with melanocyte+ADSC cocultures. Collectively, these results indicate that ADSCs can stimulate proliferation and migration of melanocytes by increasing expression of integrins in melanocytes through upregulation of production/release of melanocyte growth factors such as bFGF and SCF.

Identificação das proteínas interagentes de Yes-Associated protein (YAP), um efetor da via Hippo, em células epiteliais mamárias expostas à matriz extracelular rica em laminina / Identification of interacting proteins of Yes-Associated Protein (Yap) in mammary epithelial cells exposed to laminin-rich extracellular matrix

A sinalização da matriz extracelular (MEC) é essencial para a determinação do destino e comportamento de células epiteliais da glândula mamária. Entretanto, pouco é conhecido sobre os mecanismos moleculares envolvidos nesse processo. A via Hippo, uma cascata de sinalização que participa da regulação de diversos comportamentos celulares, incluindo o tamanho de órgãos, parece ser uma importante candidata a mediadora sinalização da MEC. Resultados preliminares do laboratório indicam que a arquitetura tecidual e a membrana basal, componente da MEC de epitélios e outros tecidos, influenciam a localização, concentração e atividade de YAP, uma proteína efetora da via Hippo, em células epiteliais mamárias. Neste contexto, o objetivo deste trabalho foi identificar as proteínas que interagem com Yap (ortólogo de YAP em camundongo) nas células epiteliais da glândula mamária em resposta à membrana basal. Foram utilizadas células EpH4, uma linhagem mamária não-tumoral murina, como modelo de diferenciação funcional e formação de ácinos em um ensaio de cultura tridimensional (3D). O tratamento de estruturas multicelulares 3D pré-formadas em placas nãoadesiva com uma matriz rica em laminina (lrECM) alterou a localização e o padrão subcelular de Yap, assim como a expressão gênica de membros da via Hippo e dos alvos de Yap, mas não alterou a expressão das proteínas da via em nível de proteína. O ensaio de co-imunoprecipitação (CoIP) seguida de análise por espectrometria de massas identificou um conjunto diferencial de proteínas que interagem com Yap na fração citoplasmática de células EpH4 cultivadas na ausência ou na presença de lrECM em um modelo de ECM-overlay. Uma análise realizada junto à database KEGG Pathways revelou que os possíveis interagentes Yap nas células cultivadas não-tratadas com lrECM participam de processos relacionados à proteólise mediada por ubiquitina, enquanto nas células expostas à lrECM os possíveis interagentes estão associados a processos metabólicos e são especialmente proteínas-chave do metabolismo de lipídios. A busca na plataforma de redes de interação STRING não identificou trabalhos que destaquem a interação de Yap com estas proteínas. A plataforma Vizit indica a participação de Yap em processos relacionados à síntese e atividade de lipídios e hormônios, o que reforça as evidências de que está pode ser uma nova função de Yap ainda não explorada em detalhes. A fim de se obter resultados complementares à CoIP, padronizamos o ensaio de identificação por biotinilação dependente de proximidade (BioID) em células embrionárias de rim humano da linhagem 293FT. As proteínas isoladas por pulldown foram identificadas por espectrometria de massas e uma análise junto à database Gene Ontology indicou que os possíveis interagentes de Yap nestas células são em sua maioria proteínas relacionadas à via Hippo, o que reforça a robustez do ensaio. Nós pretendemos transpor este sistema para as células EpH4. A expectativa é que, em conjunto, estes resultados nos orientem em projetos futuros para compreender os mecanismos de sinalização da MEC na morfogênese e diferenciação da glândula mamária

Extracellular matrix (ECM)-signaling is crucial for determination of epithelial cell fate and behavior in the mammary gland. However, little is known about the molecular mechanisms involved in these processes. The Hippo pathway, a signaling cascade involved in the regulation of several cellular processes, including organ size, seems to be an important candidate as a mediator of this signaling. Our preliminary results indicate that the tissue architecture and the basement membrane, an ECM component of epithelia and other tissues, influence the location, level and activity of YAP, an effector of the Hippo pathway. In this context, the goal of this work was to identify the proteins that interact with Yap (ortholog of YAP in mouse) in mammary epithelial cells in response to the basement membrane. We used EpH4 cells, a nontumoral murine mammary cell, in a functional differentiation and acini-forming in tridimensional (3D) culture assay. Treatment of 3D multicellular structures pre-formed on nonadhesive plates with a laminin-rich extracellular matrix (lrECM) altered the subcellular localization and pattern of Yap, as well as gene expression of Hippo pathway proteins and Yap targets, but did not altered the expression of the pathway members at the protein level. Coimmunoprecipitation (CoIP) followed by mass spectrometry analysis identified a differential set of proteins interacting with Yap in cytoplasmic fractions of EpH4 cells in the absence or presence of lrECM in an ECM-overlay culture model. An analysis performed with the KEGG Pathways database revealed that putative Yap interactors in non-treated cells participate in processes related to ubiquitin-mediated proteolysis, whereas in cells exposed to lrECM Yap interactors are associated to metabolic processes and are mainly key-proteins of metabolism of lipids and carbohydrates. A search in interaction networks platform STRING did not identify previous works that showing the interaction of Yap with these proteins. Vizit platform indicated the participation of Yap in processes related to the synthesis and activity of lipids and hormones, which reinforces the evidences that Yap can play a novel poorly explored role. To obtain complementary results to CoIP, we devised the proximity-dependent biotinylation identification (BioID) assay on embryonic renal cells of 293FT cell line. Pulldown-isolated proteins were identified by mass spectrometry and an analysis performed with Gene Ontology database revealed that putative Yap interactors are Hippo pathway-related proteins, which reinforces the robustness of the assay. We intend to transpose this system to the EpH4 cells. We expect that, together, these results will guide us in future projects to understand the signaling mechanisms of ECM in mammary gland morphogenesis and differentiation

TNF-alpha increases angiogenic potential in a co-culture system of dental pulp cells and endothelial cells

Abstract We recently demonstrated that a co-culture system of human umbilical vein endothelial cells (HUVECs) and human dental pulp stem cells (hDPSCs) could enhance angiogenesis ability in vitro. However, whether tumor necrosis factor α (TNF-α) could promote blood vessel formation during pulp regeneration remained unknown. The aim of this study was to investigate the effects of TNF-α on the formation of endothelial tubules and vascular networks in a co-culture system of hDPSCs and HUVECs. hDPSCs were co-cultured with HUVECs at a ratio of 1:5. The Matrigel assay was performed to detect the total tubule branching lengths and numbers of branches, and the Cell-Counting Kit 8 assay was performed to examine the effect of TNF-α on cell proliferation. Real-time polymerase chain reactions and western blot were used to detect vascular endothelial growth factor (VEGF) mRNA and protein expression. The Matrigel assay showed significantly greater total branching lengths and numbers of branches formed in the experimental groups treated with different concentrations of TNF-α compared with the control group. The decomposition times of the tubule structures were also significantly prolonged (P < 0.05). Treatment with 50 ng/ml TNF-α did not significantly change the proliferation of co-cultured cells, but it significantly increased the VEGF mRNA and protein expression levels (p < 0.05). In addition, the migration abilities of HUVECs and hDPSCs increased after co-culture with TNF-α (p < 0.05). TNF-α enhanced angiogenic ability in vitro in the co-culture system of hDPSCs and HUVECs.

Morphological observation of bone marrow mesenchymal stem cells under matrigel three dimensional culture conditions / Observación morfológica de células madre mesenquimales de médula ósea en condiciones de cultivo tridimensional con matrigel

SUMMARY: Matrigel is a basement membrane matrix extracted from the EHS mouse tumor containing extracellular matrix protein, its main components are laminin, type IV collagen, nestin, heparin sulfate, growth factor and matrix metalloproteinase.At room temperature, Matrigel polymerized to form a three dimensional matrix with biological activity. It can simulate the structure, composition, physical properties and functions of the cell basement membrane in vivo, which is beneficial to the culture and differentiation of the cells in vitro, and can be used for the study of cell morphology, biochemical function, migration, infection and gene expression. In this study, Matrigel three-dimensional culture model of bone marrow mesenchymal stem cells(BMSCs) was established, and its morphology, proliferation and survival were observed. BMSCs were isolated and cultured with whole bone marrow adherence method. The Second generation BMSCs with good growth condition were selected and mixed with Matrigel to form cell gel complexes. The morphology and proliferation of mesenchymal stem cells were observed by phase contrast microscope and HE staining,Live/Dead staining was used to evaluate the cell activity.Phase contrast microscopy showed that BMSCs were reticulated in Matrigel and proliferated well, After 7 days, the matrix gel gradually became soft and collapsed, a few cell reticular crosslinking growth was seen at 14 days; HE staining showed that the cytoplasm of the cells was larger on the fourth day and the cells were elongated and cross-linked on the seventh day; Live/dead staining showed that most cells showed green fluorescence with the prolongation of culture time, on the first, 4 and 7 days, the activity of bone marrow mesenchymal stem cells in Matrigel gradually increased, and the percentages were 92.57 %, 95.54 % and 97.37 %, respectively. Matrigel three-dimensional culture system can maintain the morphology, function and proliferation ability of bone marrow mesenchymal stem cells.

RESUMEN: Matrigel es una matriz de membrana basal extraída del tumor de ratón EHS que contiene proteína de matriz extracelular. Los componentes principales son laminina, el colágeno tipo IV, nestina, sulfato de heparina, factor de crecimiento y metaloproteinasa de matriz. A temperatura ambiente, Matrigel se polimerizó para formar una matriz tridimensional. Es posible simular la estructura, la composición, las propiedades físicas y las funciones de la membrana basal celular in vivo, lo que es beneficioso para el cultivo y la diferenciación de las células in vitro, y se puede utilizar para el estudio de la morfología celular, la función bioquímica, la migración, infección y expresión génica. En este estudio, se estableció el modelo de cultivo tridimensional Matrigel de células madre mesenquimales de médula ósea (BMSC), y se observó su morfología, proliferación y supervivencia. Las BMSC fueron aisladas y cultivadas con el método de adherencia de la médula ósea completa. Se seleccionaron las BMSC de segunda generación con buenas condiciones de crecimiento y se mezclaron con Matrigel para formar complejos de gel de células. La morfología y la proliferación de las células madre mesenquimales se observaron con microscopio de contraste de fase y se tiñó con Hematoxilina-Eosina (HE); para evaluar la actividad celular se usó la tinción Live/Dead. La microscopía de contraste mostró que las BMSC se reticularon en Matrigel y proliferaron bien. Después de 7 días, se observó que el gel de matriz gradualmente se volvió blando y colapsó, y se visualizó un cruce transversal de algunas células reticulares a los 14 días. La tinción mostró que la mayoría de las células mostraron una fluorescencia verde con la prolongación del tiempo de cultivo; en los primeros 4 y 7 días, la actividad de las células madre mesenquimales de la médula ósea en Matrigel aumentó gradualmente y los porcentajes fueron de 92,57 %, 95,54 % y 97,37 %, respectivamente. El sistema de cultivo tridimensional de Matrigel puede mantener la morfología, la función y la capacidad de proliferación de las células madre mesenquimales de la médula ósea.

Preparation and Characterization of Human Adipose Tissue-Derived Extracellular Matrix, Growth Factors, and Stem Cells: A Concise Review

BACKGROUND: Human adipose tissue is routinely discarded as medical waste. However, this tissue may have valuable clinical applications since methods have been devised to effectively isolate adipose-derived extracellular matrix (ECM), growth factors (GFs), and stem cells. In this review, we analyze the literature that devised these methods and then suggest an optimal method based on their characterization results. METHODS: Methods that we analyze in this article include: extraction of adipose tissue, decellularization, confirmation of decellularization, identification of residual active ingredients (ECM, GFs, and cells), removal of immunogens, and comparing structural/physiological/biochemical characteristics of active ingredients. RESULTS: Human adipose ECMs are composed of collagen type I–VII, laminin, fibronectin, elastin, and glycosaminoglycan (GAG). GFs immobilized in GAG include basic fibroblast growth factor (bFGF), transforming growth factor beta 1(TGF-b1), insulin like growth factor 1 (IGF-1), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), BMP4 (bone morphogenetic protein 4), nerve growth factor (NGF), hepatocyte growth factor (HGF), and epithermal growth factor (EGF). Stem cells in the stromal-vascular fraction display mesenchymal markers, self-renewal gene expression, and multi-differentiation potential. CONCLUSION: Depending on the preparation method, the volume, biological activity, and physical properties of ECM, GFs, and adipose tissue-derived cells can vary. Thus, the optimal preparation method is dependent on the intended application of the adipose tissue-derived products.

Terapias alternativas para o diabetes mellitus tipo 1: caracterização funcional do gene Txnip na diferenciação ß-pancreática e desenvolvimento de biomaterial inovador para microencapsulamento celular / Alternative therapies for type 1 diabetes mellitus: functional characterization of Txnip gene during -pancreatic differentiation and generation of an innovative biomaterial for cell microencapsulation

O diabetes mellitus do tipo 1 (DM1) é uma doença causada pela destruição autoimune das células-ß produtoras de insulina do pâncreas. O transplante de ilhotas pancreáticas é um procedimento tecnicamente simples sendo uma alternativa terapêutica interessante para o DM1. Entretanto, a oferta limitada de pâncreas de doadores falecidos e a necessidade de imunossupressão crônica são fatores que limitam a aplicabilidade dessa modalidade de transplante. Neste trabalho foram estudadas duas estratégias que visam oferecer soluções aos fatores limitantes do transplante de ilhotas pancreáticas. Na primeira parte do trabalho, o mecanismo molecular que dirige o processo de diferenciação de células-tronco embrionárias murinas (murine embryonic stem cells, mESCs) em células produtoras de insulina (insulin producing cells, IPCs) foi analisado visando otimizar o processo de diferenciação. Nós selecionamos o gene Thioredoxin interacting protein (Txnip), diferencialmente expresso ao longo da diferenciação ß-pancreática, para realizar um estudo funcional através da modificação genética de mESCs. Os resultados obtidos permitiram verificar que a inibição de Txnip na diferenciação ß-pancreática pode induzir a diferenciação de IPCs com maior expressão de marcadores de células- e mais responsivas ao estímulo de glicose. Além disso, o modelo de zebrafish permitiu elucidar in vivo o papel de Txnip durante a organogênese pancreática, revelando que a inibição desse gene é capaz de aumentar a massa de células-ß através do estimulo de células presentes no ducto extra-pancreático. Dessa forma, a inibição de Txnip pode aprimorar os protocolos para obtenção de IPCs a partir de células-tronco pluripotentes. A exposição crônica a agentes imunossupressores diabetogênicos e a perda de componentes de matriz extracelular durante o isolamento de ilhotas pancreáticas são causas para a perda de funcionalidade do enxerto. Dessa forma, na segunda parte do trabalho, um biomaterial inovador foi desenvolvido, contendo um polímero de laminina (polilaminina, PLn) para o encapsulamento e a imunoproteção de ilhotas pancreáticas. As cápsulas produzidas com o biomaterial desenvolvido, Bioprotect-Pln, são térmica- e mecanicamente estáveis, além de serem biocompatíveis e capazes de imunoproteger ilhotas pancreáticas humanas in vitro. O encapsulamento com Bioprotect-Pln preserva a funcionalidade de ilhotas pancreáticas. Além disso, quando cápsulas vazias de Bioprotect-Pln foram implantadas em camundongos imunocompetentes, houve atenuação da resposta inflamatória ao implante, uma das principais causas para perda de funcionalidade de enxertos encapsulados. Os resultados obtidos indicam que a presença de polilaminina na malha capsular induz uma resposta anti-inflamatória que pode beneficiar a preservação do enxerto de ilhotas pancreáticas encapsuladas. Atualmente, o transplante de ilhotas pancreáticas é visto como a terapia celular mais promissora para atingir a independência de insulina em pacientes de DM1, porém, a aplicabilidade desse transplante ainda é limitada. Este trabalho contribuiu para a elucidação dos mecanismos moleculares que podem aprimorar o processo de diferenciação de célulastronco pluripotentes em IPCs, estabelecendo uma fonte alternativa de células para a terapiade reposição, e, também, estabeleceu um biomaterial inovador, capaz de diminuir a resposta inflamatória ao implante de microcápsulas e de imunoproteger células microencapsuladas. Desta forma, este trabalho contribui para o estabelecimento da terapia de reposição celular para pacientes de DM1

Type 1 diabetes mellitus (DM1) is a disease caused by the autoimmune destruction of insulin-producing pancreatic ß-cells. Pancreatic islet transplantation is a technically simple procedure and an interesting alternative therapy for DM1, however, the limited supply of cadaveric donated pancreas and the need of life-long immunosuppression are factors which limit its applicability. In the present work, two strategies were employed aiming at establishing viable solutions for the factors limiting pancreatic islet transplantation. In the first part of this study, the molecular mechanism which drives differentiation of murine embryonic stem cells (mESCs) into insulin producing cells (IPCs) was analyzed in order to optimize the differentiation process. The Thioredoxin interacting protein (Txnip) gene, which is differentially expressed along -pancreatic differentiation, was selected to undergo a functional analysis by genetically modifying mESCs. The results allowed us to verify that Txnip inhibition during the ß-pancreatic differentiation process can induce differentiation of IPCs displaying higher expression of ß-cell markers and being more responsive to glucose stimuli. In addition, the zebrafish model allowed us to elucidate in vivo the role of Txnip during pancreatic organogenesis, revealing that its inhibition is able to increase the mass of ß-cells through stimulation of extra-pancreatic ductal cells. Therefore, Txnip inhibition may turbinate IPCs differentiation from pluripotent stem cells. The chronic exposure to diabetogenic immunosuppressive agents and the loss of extracellular matrix components during isolation of pancreatic islets are probable causes for the loss of pancreatic islet graft functionality. Therefore, in the second part of this study, an innovative biomaterial was developed by incorporating a laminin polymer (polylaminin, PLn) for the encapsulation and immunoprotection of pancreatic islets. The capsules produced with the novel biomaterial, Bioprotect-Pln, are biocompatible, thermally and mechanically stable and are able to immunoprotect human pancreatic islets in vitro. Encapsulation with Bioprotect-Pln preserves the functionality of pancreatic islets. In addition, when empty Bioprotect-Pln capsules were implanted into immunocompetent mice, an attenuation of the inflammatory response to the implant occurred, this being one of the main causes of encapsulated graft loss. The results indicate that polylaminin addition to the capsular mesh induces an anti-inflammatory response which may favor preservation of the engrafted encapsulated pancreatic islets. Pancreatic islet transplantation is currently seen as the most promising cell therapy to achieve insulin independence in DM1 patients, however, the applicability of this transplant is still limited. This work contributed to the elucidation of the molecular mechanisms which can turbinate the differentiation of pluripotent stem cells into IPCs, establishing an alternative source of cells for the replacement therapy, and, also, established an innovative biomaterial which is able to decrease the inflammatory response to the graft, thereby immunoprotecting the microencapsulated cells. Therefore, this work contributes to the establishment of the cell replacement therapy for DM1 patients

Decellularization of placentas: establishing a protocol

Biological biomaterials for tissue engineering purposes can be produced through tissue and/or organ decellularization. The remaining extracellular matrix (ECM) must be acellular and preserve its proteins and physical features. Placentas are organs of great interest because they are discarded after birth and present large amounts of ECM. Protocols for decellularization are tissue-specific and have not been established for canine placentas yet. This study aimed at analyzing a favorable method for decellularization of maternal and fetal portions of canine placentas. Canine placentas were subjected to ten preliminary tests to analyze the efficacy of parameters such as the type of detergents, freezing temperatures and perfusion. Two protocols were chosen for further analyses using histology, scanning electron microscopy, immunofluorescence and DNA quantification. Sodium dodecyl sulfate (SDS) was the most effective detergent for cell removal. Freezing placentas before decellularization required longer periods of incubation in different detergents. Both perfusion and immersion methods were capable of removing cells. Placentas decellularized using Protocol I (1% SDS, 5 mM EDTA, 50 mM TRIS, and 0.5% antibiotic) preserved the ECM structure better, but Protocol I was less efficient to remove cells and DNA content from the ECM than Protocol II (1% SDS, 5 mM EDTA, 0.05% trypsin, and 0.5% antibiotic).

Extracellular matrix and fibroblast injection produces pterygium-like lesion in rabbits

BACKGROUND: Translational research to develop pharmaceutical and surgical treatments for pterygium requires a reliable and easy to produce animal model. Extracellular matrix and fibroblast are important components of pterygium. The aim of this study was to analyze the effect of the subconjunctival injection of fibroblast cells (NIH3T3 cell line) and exogenous extracellular matrix in rabbits in producing a pterygium-like lesion. METHODS: Six 3-month-old white New Zealand rabbits were injected with 20,000 NIH3T3 cells and 5 µL of Matrigel in the right conjunctiva, and with only 5 µL of Matrigel in the left conjunctiva. The eyes were photographed under a magnification of 16× using a 12-megapixel digital camera attached to the microscope on day 1,3 and 7. Conjunctival vascularization was measured by analyzing images to measure red pixel saturation. Area of corneal and conjunctival fibrovascular tissue formation on the site of injection was assessed by analyzing the images on day 3 and 7 using area measurement software. Histopathologic characteristics were determined in the rabbit tissues and compared with a human primary pterygium. RESULTS: The two treatments promoted growth of conjunctival fibrovascular tissue at day 7. The red pixel saturation and area of fibrovascular tissue developed was significantly higher in right eyes (p < 0.05). Tissues from both treatments showed neovascularization in lesser extent to that observed in human pterygium. Acanthosis, stromal inflammation, and edema were found in tissues of both treatments. No elastosis was found in either treatment. CONCLUSIONS: Matrigel alone or in combination with NIH3T3 cells injected into the rabbits' conjunctiva can promote tissue growth with characteristics of human pterygium, including neovascularization, acanthosis, stromal inflammation, and edema. The combination of Matrigel with NIH3T3 cells seems to have an additive effect on the size and redness of the pterygium-like tissue developed.

Laminin and Platelet-Derived Growth Factor-BB Promote Neuronal Differentiation of Human Urine-Derived Stem Cells

Urine-derived stem cells (USCs) are considered as a promising cell source capable of neuronal differentiation. In addition, specific growth factors and extracellular matrix are essential for enhancing their neuronal differentiation efficiency. In this study, we investigated the possibility of neuronal differentiation of USCs and the role of laminin and platelet-derived growth factor BB (PDGF-BB) as promoting factors. USCs were isolated from fresh urine of healthy donors. Cultured USCs were adherent to the plate and their morphology was similar to the cobblestone. In addition, they showed chromosome stability, rapid proliferation rate, colony forming capacity, and mesenchymal stem cell characteristics. For inducing the neuronal differentiation, USCs were cultured for 14 days in neuronal differentiation media supplemented with/without laminin and/or PDGF-BB. To identify the expression of neuronal markers, RT-PCR, flow cytometry analysis and immunocytochemistry were used. After neuronal induction, the cells showed neuron-like morphological change and high expression level of neuronal markers. In addition, laminin and PDGF-BB respectively promoted the neuronal differentiation of USCs and the combination of laminin and PDGF-BB showed a synergistic effect for the neuronal differentiation of USCs. In conclusion, USCs are noteworthy cell source in the field of neuronal regeneration and laminin and PDGF-BB promote their neuronal differentiation efficiency.

Three-dimensional Culture of Human Airway Epithelium in Matrigel for Evaluation of Human Rhinovirus C and Bocavirus Infections / 生物医学与环境科学（英文）

OBJECTIVE@#Newly identified human rhinovirus C (HRV-C) and human bocavirus (HBoV) cannot propagate in vitro in traditional cell culture models; thus obtaining knowledge about these viruses and developing related vaccines are difficult. Therefore, it is necessary to develop a novel platform for the propagation of these types of viruses.@*METHODS@#A platform for culturing human airway epithelia in a three-dimensional (3D) pattern using Matrigel as scaffold was developed. The features of 3D culture were identified by immunochemical staining and transmission electron microscopy. Nucleic acid levels of HRV-C and HBoV in 3D cells at designated time points were quantitated by real-time polymerase chain reaction (PCR). Levels of cytokines, whose secretion was induced by the viruses, were measured by ELISA.@*RESULTS@#Properties of bronchial-like tissues, such as the expression of biomarkers CK5, ZO-1, and PCK, and the development of cilium-like protuberances indicative of the human respiration tract, were observed in 3D-cultured human airway epithelial (HAE) cultures, but not in monolayer-cultured cells. Nucleic acid levels of HRV-C and HBoV and levels of virus-induced cytokines were also measured using the 3D culture system.@*CONCLUSION@#Our data provide a preliminary indication that the 3D culture model of primary epithelia using a Matrigel scaffold in vitro can be used to propagate HRV-C and HBoV.

Inhibitory effect of andrographolide on angiogenesis induced by the supernatant from cultured tumor cells / 中南大学学报(医学版)

To determine the effect of andrographolide (Andro) on angiogenesis of human umbilical vein endothelial cells (HUVECs).
 Methods: HUVECs were treated with different concentrations of Andro and the cell viability was detected with Cell Counting Kit-8 (CCK-8). HUVECs were treated with half lethal dose (IC50) of Andro. Matrigel was used to make capillary formation of HUVECs and the effect of Andro on capillary formation was evaluated by calculating the percentage of capillary formation. Moreover, the effects of Andro and the supernatant from cultured A549 tumor cells on capillary formation were evaluated by calculating the percentage of capillary formation. The effect of Andro on the expression of matrix metalloproteinase-9 (MMP-9) was determined with Western blot.
 Results: The cell viability of HUVECs decreased with the increase of Andro concentrations. IC50 was 20 μmol/L. The capillary formation of HUVECs was inhibited when treated with 20 μmol/L Andro for 24 hours. Moreover, Andro was able to antagonize the promotion of the capillary formation induced by the supernatant from cultured tumor cells. Andro could suppress the expression of MMP-9 and antagonize the capillary formation.
 Conclusion: Andro inhibits the capillary formation of HUVECs and can antagonize the promotion of angiogenesis induced by the supernatant from cultured tumor cells.

The subsequent biological effects of simulated microgravity on endothelial cell growth in HUVECs / 中华创伤杂志(英文版)

<p><b>PURPOSE</b>Microgravity is known to cause endothelium dysfunction in astronauts returning from spaceflight. We aimed to reveal the regulatory mechanism in alterations of human endothelial cells after simulated microgravity (SMG).</p><p><b>METHODS</b>We utilized the rotary cell culture system (RCCS-1) to explore the subsequent effects of SMG on human umbilical vein endothelial cells (HUVECs).</p><p><b>RESULTS</b>SMG-treated HUVECs appeared obvious growth inhibition after return to normal gravity, which might be attributed to a set of responses including alteration of cytoskeleton, decreased cell adhesion capacity and increased apoptosis. Expression levels of mTOR and its downstream Apaf-1 were increased during subsequent culturing after SMG. miR-22 was up-regulated and its target genes SRF and LAMC1 were down-regulated at mRNA levels. LAMC1 siRNAs reduced cell adhesion rate and inhibited stress fiber formation while SRF siRNAs caused apoptosis.</p><p><b>CONCLUSION</b>SMG has the subsequent biological effects on HUVECs, resulting in growth inhibition through mTOR signaling and miR-22-mediated mechanism.</p>