Displasia fibrosa ósea / Fibrous dysplasia of bone

La displasia fibrosa ósea es un trastorno no hereditario del desarrollo esquelético caracterizado por una proliferación anormal de fibroblastos y diferenciación deficiente de osteoblastos que conduce a un reemplazo del tejido óseo esponjoso por tejido conectivo fibroso. Es producida por una mutación somática activadora del gen GNAS1 que induce una activación y proliferación de células mesenquimales indiferenciadas con formación de tejido fibroso y trabéculas óseas anómalas. Existen formas monostóticas, poliostóticas y craneofaciales con diversos grados de dolor, deformidades y fracturas óseas, aunque muchos casos son asintomáticos. En ocasiones se producen quistes óseos aneurismáticos, hemorragias, compromisos neurológicos y raramente osteosarcomas. Algunos casos se asocian a síndrome de McCune-Albright, síndrome de Mazabraud y a osteomalacia por hipofosfatemia por pérdida tubular renal inducida por el FGF23 producido por el tejido displásico. Los hallazgos en las radiografías convencionales son característicos, aunque variables y de carácter evolutivo. La gammagrafía ósea es la técnica de imagen con mayor sensibilidad para determinar la extensión de la enfermedad. El diagnóstico diferencial incluye múltiples lesiones óseas de características similares y en raras ocasiones se requiere biopsia ósea o estudio genético para confirmarlo. No existe un consenso unánime acerca del abordaje terapéutico de estos pacientes, razón por la cual es necesario un enfoque multidisciplinario. La conducta puede ser expectante o quirúrgica según el tipo de lesiones y es importante el manejo del dolor y de las endocrinopatías asociadas. La mayor experiencia publicada se refiere al uso de bifosfonatos y, más recientemente, denosumab. Los tratamientos actuales son insuficientes para modificar el curso de la enfermedad y es necesario el desarrollo de nuevas moléculas que actúen específicamente en el gen GNAS1 o sobre las células mesenquimales afectadas. (AU)

Fibrous dysplasia of bone is a noninherited developmental anomaly of bone characterized by abnormal proliferation of fibroblasts and differentiation of osteoblasts that cause a replacement of trabeculous bone by fibrous connective tissue. It is caused by a somatic mutation in the GNAS1 gene, which induces an undifferentiated mesenquimal cells activation and proliferation with formation of fibrous tissue and abnormal osseous trabeculae. There are monostotic, polyostotic and craniofacial variants with different grades of bone pain, deformities and fractures, although many cases remain asymptomatic. Aneurysmal bone cysts, bleeding, neurological compromise and infrequently osteosarcoma are possible complications. Some cases are associated to McCune-Albright syndrome, Mazabraud syndrome or hypophosphatemia and osteomalacia due to to renal tubular loss induced by FGF23 produced by dysplastic tissue. The findings on conventional radiography are characteristic although variable and evlolve with time. Bone scintigraphy is the most sensitive technique to evaluate the extent of disease. Differential diagnosis include several osseous lesions of similar appearance and, in some cases, bone biopsy or genetic testing may be necessary. Today, there is no consensus regarding the therapeutic approach for these patients and it is necessary a multidisciplinary medical team. Watchful waiting or surgical interventions can be indicated, depending on the type of bone lesions. Bone pain and associated endocrinopathies management are very important. Most published experience refers to the use of bisphosphonates and, more recently, denosumab. Current treatments are insufficient to modify the natural curse of the disease and therefore, new molecules with specific action on GNAS1 gene or affected mesenchymal cells are necessary. (AU)

Goat umbilical cord cells are permissive to small ruminant lentivirus infection in vitro

Abstract Small ruminant lentiviruses isolated from peripheral blood leukocytes and target organs can be propagated in vitro in fibroblasts derived from goat synovial membrane cells. These cells are obtained from tissues collected from embryos or fetuses and are necessary for the establishment of the fibroblast primary culture. A new alternative type of host cells, derived from goat umbilical cord, was isolated and characterized phenotypically with its main purpose being to obtain cell monolayers that could be used for the diagnosis and isolation of small ruminant lentiviruses in cell culture. To accomplish this goal, cells were isolated from umbilical cords; characterized phenotypically by flow cytometry analysis; differentiate into osteogenic, chondrogenic and adipogenic lineage; and submitted to viral challenge. The proliferation of goat umbilical cord cells was fast and cell monolayers formed after 15 days. These cells exhibited morphology, immunophenotype, growth characteristics, and lineage differentiation potential similar to mesenchymal stem cells of other origins. The goat umbilical cord derived cells stained positive for vimentin and CD90, but negative for cytokeratin, CD34 and CD105 markers. Syncytia and cell lysis were observed in cell monolayers infected by CAEV-Cork and MVV-K1514, showing that the cells are permissive to small ruminant lentivirus infection in vitro. These data demonstrate the proliferative competence of cells derived from goat umbilical cords and provide a sound basis for future research to standardize this cell lineage.

Wharton's jelly cells from sheep umbilical cord maintained with different culture media are permissive to in vitro infection by Small Ruminant Lentiviruses / Células da geleia de Wharton do cordão umbilical ovino mantidas em diferentes meios de cultivo são permissivas à infecção in vitro por lentivírus de pequenos ruminantes

This study aimed to isolate cells from the Wharton's jelly of umbilical cord (WJUC) of sheep collected during natural parturition using different culture media, in addition to reporting for the first time the permissiveness of these cells to in vitro infection by small ruminant lentiviruses. Ten umbilical cords were collected from healthy sheep. Each cord explants were grown in different media consisting of MEM, low glucose DMEM, M199, and RPMI-1640. The permissiveness of infection of sheep cells from WJUC was tested with CAEV-Cork and MVV-K1514 strains, inoculating 0.1 MOI of each viral strain. Four supernatants from each strain were obtained from WJUC sheep cell cultures infected in different media. The results demonstrated the presence of cytopathic effect after the in vitro infection by CAEV-Cork and MVV-K1514 with all of the tested culture media. Nested-PCR detected proviral DNA in all supernatants. Supernatants containing CAEV-Cork viruses had TCID 50/ml titres of 10 5.5 in MEM, 10 4.0 in low glucose DMEM, 105.0 in M199, and 10 5.7 in RPMI-1640. Supernatants containing the MVV-K1514 virus had TCID 50/ml titres of 10 4.3 in MEM, 10 3.5 in low-glucose DMEM, 10 4.7 in M199, and 10 3.5 in RPMI-1640. Sheep cells from WJUC are permissive to in vitro infection by small ruminant lentivirus.(AU)

O objetivo deste estudo foi isolar células da geleia de Wharton do cordão umbilical (GWCU) ovino coletado por ocasião do parto natural, utilizando-se diferentes meios de cultivo, além de relatar, pela primeira vez, sua permissividade à infecção in vitro por lentivírus de pequenos ruminantes (LVPRs). Dez cordões umbilicais foram coletados de ovelhas hígidas e soronegativas para LVPRs pelo teste de imunodifusão em gel de agarose (IDGA). De cada cordão, explantes foram cultivados em quatro meios distintos que consistiram em MEM, DMEM baixa glicose, meio 199 e RPMI-1640, todos acrescidos de 10% de soro fetal bovino em estufa com atmosfera úmida e 5% de CO2 a 37ºC. A permissividade de infecção das células GWCU ovino foi testada frente às cepas CAEV-Cork e MVV-K1514, inoculando-se 0,1 MOI de cada cepa viral e corando as monocamadas com May Grunwald Giemsa para visualização do efeito citopático. Foram obtidos quatro sobrenadantes CAEV-Cork e quatro MVV-K1514, provenientes do cultivo de células GWCU ovino infectadas por 21 dias em meios distintos, dos quais foram realizadas titulação em membrana sinovial caprina e extração do DNA pró-viral para realização de nested-PCR e eletroforese em gel de agarose a 2%. Os resultados demonstraram a presença de efeito citopático na infecção in vitro tanto por CAEV-Cork como por MVV-K1514 em todos os meios de cultivo, sendo visualizados sincícios e lise celular em microscópio invertido. A nested-PCR detectou o DNA pró-viral tanto do CAEV-Cork como do MVV-K1514 em todos os sobrenadantes. Os sobrenadantes contendo o vírus CAEV-Cork apresentaram títulos em TCID50/mL de 10 5,5 em MEM, 10 4,0 em DMEM baixa glicose, 10 5,0 em meio 199 e 10 5,7 em RPMI-1640. Os sobrenadantes contendo o vírus MVV-K1514 apresentaram título em TCID 50/mL de 10 4,3 em MEM, 10 3,5 em DMEM baixa glicose, 10 4,7 em meio 199 e 10 3,5 em RPMI-1640. Células GWCU ovino são permissivas à infecção in vitro pelos lentivírus de pequenos ruminantes CAEV-Cork e MVV-K1514.(AU)

Enxerto autólogo de células-tronco derivadas do tecido adiposo: uma nova visão de sua aplicação no tratamento de queimados e na cirurgia plástica reparadora / Adipose tissue-derived stem cell autologous grafts: a new approach to application in the treatment of burn victims and reconstructive plastic surgery

No Brasil, 1 milhão de acidentes com queimaduras acontecem por ano e as infecções são responsáveis por 75% dos óbitos nestes pacientes, além de deixar lesões que ocasionam deformidades nas áreas atingidas. Sendo assim, o objetivo deste trabalho é fornecer uma visão atual sobre células-tronco mesenquimais (MSCs), com ênfase nas células-tronco derivadas do tecido adiposo (ADSCs), associadas a gel de plasma, gel de fibrina e membranas (scaffold). O uso de géis e membranas tendem a auxiliar o crescimento celular visando sua possível aplicação na Cirurgia Plástica Reparadora para o tratamento pacientes queimados ou que necessitam de enxerto de pele. O presente trabalho abordou de forma exploratória e narrativa o tema células-tronco mesenquimais, células-tronco mesenquimais derivadas do tecido adiposo, gel de fibrina, gel de plasma e scaffold. O tipo de pesquisa empregada foi conduzido com coleta de informações utilizando-se a Biblioteca Virtual em Saúde (BVS) e PubMed. O número absoluto de artigos publicados relacionados ao tratamento de queimaduras é considerável. Até o momento, a quantidade de pesquisas relacionadas à terapia com células-tronco derivadas do tecido adiposo, gel de fibrina, gel de plasma e scaffold para o tratamento de queimaduras apresenta-se escassa. O autoenxerto de ADSCs associado a biocurativos torna-se uma perspectiva promissora na Cirurgia Plástica Reparadora para o tratamento e recuperação de pacientes que sofreram queimaduras ou outros acidentes que necessitam de enxerto de pele. Estes recursos podem reduzir a dor e prover a dessecação da lesão, promovendo neovascularização e a reepitelização da ferida.

In Brazil, 1 million burn accidents occur annually, and subsequent wound infections account for 75% cases of deaths among these patients, in addition to inducing deformities in the affected areas. Therefore, the aim of this study was to discuss the current status of mesenchymal stem cells, with an emphasis on adipose-derived stem cells (ADSCs), in combination with plasma gel, glue fibrin, and membranes (scaffold). The use of gels and membranes supports cell growth, and aims at potential application in reconstructive plastic surgery for the treatment of burn patients or individuals requiring skin grafts. This study explores and discusses the role of mesenchymal stem cells, adipose-derived mesenchymal stem cells, glue fibrin, plasma gel, and the scaffold. This research collected information from the Virtual Health Library (VHL) and PubMed. A considerable number of articles have been published on burn treatment. However, there is little research on burn treatment with ADSCs, glue fibrin, plasma gel, and scaffold. An ADSC autograft combined with a biological dressing is promising in reconstructive plastic surgery for the treatment and recovery of burn patients or individuals with other injuries that require skin grafts. These features can reduce pain and aid in drying of the lesion, thus promoting neovascularization and wound reepithelialization.

Suppression of miR-181 a attenuates H2O2-induced death of mesenchymal stem cells by maintaining hexokinase II expression

BACKGROUND: Low survival rate of transplanted cells compromises the efficacy of cell therapy. Hexokinase II (HKII) is known to have anti-apoptotic activity through its interaction with mitochondria. The objective was to identify miRNAs targeting HKII and investigate whether miRNA-mediated modulation of HKII could improve the survival of mesenchymal stem cells (MSCs) exposed to H2O2. The expression of HKII in MSCs exposed to H2O2 was evaluated, and HKII-targeting miRNA was screened based on miRNA-target prediction databases. The effect of H2O2 on the expression of the selected HKII-targeting miRNA was examined and the effect of modulation of the selected HKII-targeting miRNA using anti-miRNA on H2O2-induced apoptosis of MSC was evaluated. RESULTS: H2O2 (600 µM) induced cell death of MSCs and decreased mitochondrial HKII expression. We have identified miR-181a as a HKII-targeting miRNA and H2O2 increased the expression of miR-181a in MSCs. Delivery of anti-miR-181a, which neutralizes endogenous miR-181a, significantly attenuated H2O2-induced decrease of HKII expression and disruption of mitochondrial membrane potential, improving the survival of MSCs exposed to H2O2. CONCLUSIONS: These findings suggest that H2O2-induced up-regulation of miR-181a contributes to the cell death of MSCs by down-regulating HKII. Neutralizing miR-181a can be an effective way to prime MSCs for transplantation into ischemic tissues.

Isolamento e caracterização de células-tronco obtidas de corações de camundongos adultos / Isolation and characterization of stem cells from hearts of adult mice

O uso de células-tronco representa uma alternativa para o tratamento das doenças que acometem o coração, devido à capacidade que essas células indiferenciadas têm de preservar sua própria população e de se diferenciar em células dos diversos tecidos, incluindo o cardíaco. Nesse trabalho comparamos as características de células-tronco isoladas a partir do tecido cardíaco e da medula óssea de camundongos transgênicos para a proteína fluorescente verde (GFP). As células-tronco cardíacas e da medula óssea apresentaram característica morfológica fibroblastóide e imunofenotípica de células-tronco mesenquimais, com alta expressão dos marcadores CD44, CD90, CD73, Sca-1 e baixa expressão dos marcadores de células hematopoiéticas. A análise citogenética revelou um cariótipo poliplóide a partir da terceira passagem das células-tronco isoladas do coração e da medula-óssea. A capacidade de diferenciação em vários tipos celulares, tais como adipócitos, osteócitos e condrócitos, também foi avaliada nas células-tronco de ambas as fontes. Tanto as células-tronco isoladas do coração como da medula óssea foram capazes de se diferenciar nessas três linhagens. Quando estimuladas com 5’azacitidina para testar o potencial cardiomiogênico das células isoladas do coração e da medula óssea, apenas as células-tronco cardíacas passaram a expressar alguns marcadores de cardiomiócitos, tais como troponina T cardíaca e GATA-4...

Stem cells are undifferentiated cells with the ability of self-renewal and differentiation into different cell types, with the potential to treat heart diseases. In the present study we compared the characteristics of stem cells isolated from the heart to bone marrow stem cells, both obtained from EGFP transgeneic mice. Cardiac and bone marrow stem cells presented fibroblastic morphology and an immunophenotype compatible with mesenchymal stem cells – high expression of CD44, CD90, CD73, Sca-1 and low expression of of hematopoietic lineage markers. Cytogenetic analysis demonstrated polyploid karyotypes after the third passage of the stem cells isolated from heart and bone marrow. Both bone marrow and heart stem cells were able to differentiate into adipocytes, osteocytes and chondrocytes. In order to test the potential of differentiation into cardiomyocytes, cells were stimulated with 5’azacytidine and only cardiac stem cells expressed heart-specific markers: cardiac T troponin and GATA-4...

In Osteoporosis, differentiation of mesenchymal stem cells (MSCs) improves bone marrow adipogenesis

The formation, maintenance, and repair of bone tissue involve close interlinks between two stem cell types housed in the bone marrow: the hematologic stem cell originating osteoclasts and mesenchymal stromal cells (MSCs) generating osteoblasts. In this review, we consider malfunctioning of MSCs as essential for osteoporosis. In osteoporosis, increased bone fragility and susceptibility to fractures result from increased osteoclastogenesis and insufficient osteoblastogenesis. MSCs are the common precursors for both osteoblasts and adipocytes, among other cell types. MSCs' commitment towards either the osteoblast or adipocyte lineages depends on suitable regulatory factors activating lineage-specific transcriptional regulators. In osteoporosis, the reciprocal balance between the two differentiation pathways is altered, facilitating adipose accretion in bone marrow at the expense of osteoblast formation; suggesting that under this condition MSCs activity and their microenvironment may be disturbed. We summarize research on the properties of MSCs isolated from the bone marrow of control and osteoporotic post-menopausal women. Our observations indicate that intrinsic properties of MSCs are disturbed in osteoporosis. Moreover, we found that the regulatory conditions in the bone marrow fluid of control and osteoporotic patients are significantly different. These conclusions should be relevant for the use of MSCs in therapeutic applications.

Ameloblastic fibrodentinoma.

Odontogenic tumors comprise a complex group of lesions of diverse histopathological types and clinical behavior. The group of mixed odontogenic tumors, which are also rare, is composed of proliferating odontogenic epithelium in a cellular ectomesenchyme resembling dental papilla. Ameloblastic fibrodentinoma is a rare benign odontogenic tumor. The present case report discusses this tumor composed of odontogenic epithelium and odontogenic mesenchyme with dentin or dentin like tissue. The present paper also throws light on various histological similarities and complexities which make the interpretation of these set of odontogenic tumors a diagnostic dilemma.

A imunomodulação dos linfócitos TCD4+ e TCD8+ induzida pelas células tronco mesenquimais / The immunomodulation of CD4 + and CD8 + T cells induced by mesenchymal stem

O transplante alogênico de medula óssea é usado como adjuvante no tratamento de neoplasias hematopoéticas, outros tumores e em algumas doenças auto-imunes, com o objetivo de restabelecer o sistema hematopoético após quimioterapia e radioterapia. A doença do enxerto contra o hospedeiro (OECH) é uma das complicações mais freqüentes deste procedimento, ocorre em mais da metade dos pacientes que são submetidos a transplante alogênico de medula óssea, e representa uma importante causa de morbidade, mortalidade e baixa qualidade de vida. As células T são as principais responsáveis pelo desenvolvimento da OECH, com o reconhecimento de antígenos estranhos por células T C04 e ativação conjunta de linfócitos T COS resultando em dano tecidual. As CTMs humanas suprimem a proliferação de linfócitos T citotóxicos e também alteram o perfil de citocinas e a maturação das células apresentadoras de antígenos, desempenhando importante função imunomoduladora, podendo, portanto, ser úteis na terapia celular contra a OECH. O objetivo central deste trabalho foi identificar as bases moleculares da imunomodulação dos linfócitos T mediada pelas CTMs. Para isso, as alterações ocasionadas no perfil de expressão gênica de linfócitos TC04 e TCOS mediante estimulo proliferativo, na presença ou ausência de CTMs, foram analisadas pela metodologia de microarray. Ambos, os linfócitos TC04+ e TCOS+ que foram imunomodulados pelas CTMs apresentaram alterações na expressão de componentes das vias do ciclo celular (G1/S) e de vias envolvidas na regulação da resposta imune, como sinalização da via NF-KB e do receptor TCR. Realizamos a validação desse estudo com base na análise de expressão gênica de componentes envolvidos nessas sinalizações, como RelA, ReIB, NF-KB2, IRAK, TNFAIP3 e BTCR (sinalização da via NF-KB); CTLA4 (sinalização TCR); GITR, FOXp3 e IL-10 (regulação da resposta imunológica). Nossos resultados demonstram que as CTMs induzem a imunomodulação dos linfócitos tanto por alterar componentes envolvidos na proliferação celular, como de genes envolvidos na resposta imunológica dessas células.

In Vivo MR Imaging of Magnetically Labeled Mesenchymal Stem Cells in a Rat Model of Renal Ischemia

OBJECTIVE: This study was designed to evaluate in vivo MR imaging for the depiction of intraarterially injected superparamagnetic iron oxide (SPIO)-labeled mesenchymal stem cells (MSCs) in an experimental rat model of renal ischemia. MATERIALS AND METHODS: Left renal ischemia was induced in 12 male Sprague-Dawley rats by use of the catheter lodging method. In vivo MR signal intensity variations depicted on T2*-weighted sequences were evaluated in both the left and right kidneys prior to injection (n = 2), two hours (n = 4), 15 hours (n = 2), 30 hours (n = 2) and 72 hours (n = 2) after injection of SPIO-labeled MSCs in both kidneys. Signal intensity variations were correlated with the number of Prussian blue stain-positive cells as visualized in histological specimens. RESULTS: In an in vivo study, it was determined that there was a significant difference in signal intensity variation for both the left and right cortex (40.8 +/- 4.12 and 26.4 +/- 7.92, respectively) and for both the left and right medulla (23.2 +/- 3.32 and 15.2 +/- 3.31, respectively) until two hours after injection (p < 0.05). In addition, signal intensity variation in the left renal cortex was well correlated with the number of Prussian blue stain-positive cells per high power field (r = 0.98, p < 0.05). CONCLUSION: Intraarterial injected SPIO-labeled MSCs in an experimental rat model of renal ischemia can be detected with the use of in vivo MR imaging immediately after injection.