MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1 / 国际口腔科学杂志·英文版

Mesenchymal stem cell (MSC)-based therapy has emerged as a promising treatment for spinal cord injury (SCI), but improving the neurogenic potential of MSCs remains a challenge. Mixed lineage leukemia 1 (MLL1), an H3K4me3 methyltransferases, plays a critical role in regulating lineage-specific gene expression and influences neurogenesis. In this study, we investigated the role and mechanism of MLL1 in the neurogenesis of stem cells from apical papilla (SCAPs). We examined the expression of neural markers, and the nerve repair and regeneration ability of SCAPs using dynamic changes in neuron-like cells, immunofluorescence staining, and a SCI model. We employed a coimmunoprecipitation (Co-IP) assay, real-time RT-PCR, microarray analysis, and chromatin immunoprecipitation (ChIP) assay to investigate the molecular mechanism. The results showed that MLL1 knock-down increased the expression of neural markers, including neurogenic differentiation factor (NeuroD), neural cell adhesion molecule (NCAM), tyrosine hydroxylase (TH), βIII-tubulin and Nestin, and promoted neuron-like cell formation in SCAPs. In vivo, a transplantation experiment showed that depletion of MLL 1 in SCAPs can restore motor function in a rat SCI model. MLL1 can combine with WD repeat domain 5 (WDR5) and WDR5 inhibit the expression of neural markers in SCAPs. MLL1 regulates Hairy and enhancer of split 1 (HES1) expression by directly binds to HES1 promoters via regulating H3K4me3 methylation by interacting with WDR5. Additionally, HES1 enhances the expression of neural markers in SCAPs. Our findings demonstrate that MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1. These results provide a potential therapeutic target for promoting the recovery of motor function in SCI patients.

O plasma rico em fatores de crescimento no tratamento de pacientes com úlceras venosas / Plasma rich in growth factors in the treatment of patients with venous ulcers

Objetivo geral: Analisar as propriedades do plasma rico em fatores de crescimento (PRGF) autólogo, para tratar pacientes com úlceras venosas. Método: Trata-se de um estudo quase- experimental realizado em um Hospital Universitário, cuja coleta de dados ocorreu no período de maio de 2016 a dezembro de 2017. Amostra composta por 18 pacientes com úlcera venosa, que atenderam aos critérios de inclusão. Os participantes compareceram por 12 semanas consecutivas, ao ambulatório para consulta de enfermagem e troca do curativo, com aplicação do PRGF a cada 15 dias. O preparo do PRGF utilizou a técnica de uma centrifugação e o gluconato de cálcio como ativador plaquetário. Realização da contagem de plaquetas e identificação dos fatores de crescimento no PRGF usado no tratamento. Resultados: Amostra homogênea quanto às variáveis socioeconômicas e clínicas, com predomínio de idosos, sexo masculino, ensino fundamental incompleto e renda entre um e dois salários mínimos. Obtenção de um PRGF com contagem baixa de plaquetas, mediana de 122 x 103 mm3 plaquetas, mas com principais fatores de crescimento plaquetários envolvidos na cicatrização (PDGF-AB, PDGF-BB, TGF-ß, VEGF, EGF e FGF2). Houve alta variabilidade na contagem de plaquetas e na concentração de fatores de crescimento, com correlação forte e significativa entre a quantidade de plaquetas e os fatores de crescimento PDGF-AB e PDGF-BB. As médias de cada fator de crescimento foram 1,52 ng/ml para o PDGF-AB, 1,38 ng/ml para o PDGF-BB, 1,40 ng/ml para o TGF-ß, 0,99 ng/ml para VEGF, 1,57 ng/ml para o EGF e 1.04 ng/ml para o FGF2. O tamanho inicial médio das úlceras neste estudo foi de 29,6 ± 23,9 /cm2 e o percentual médio de redução da área após 12 semanas de tratamento foi de 46,2%. O tamanho das úlceras após tratamento era significativamente menor do que o tamanho inicial das úlceras (p-valor do teste de Wilcoxon igual a 0,001). Entretanto, a redução da área das úlceras, no período das 12 semanas, não apresentou correlação com as concentrações dos fatores de crescimento no PRGF. A percentagem de tecido de epitalização apresentou crescimento em todo período do estudo com aumento significativo ao final de 12 tratamento (média = 58,1%) e o tecido desvitalizado apresentou decrescimento durante todo o período do estudo com redução significativa ao final de 12 semanas (média = 11%). Ao final de 12 semanas observou-se uma melhora significativa do tipo de exsudato nas úlceras e uma diminuição significativa da quantidade de exsudato nas úlceras. Conclusão: Neste estudo, foi confirmada a hipótese nula em que a concentração dos fatores de crescimento presentes no PRGF não apresentou relação estatisticamente significativa com a redução da área das úlceras venosas.

Objective: To analyze the properties of autologous plasma rich in growth factors (PRGF), to treat patients with venous ulcers. Method: It is a quasi-experimental clinical study performed in a University Hospital, the data collection occurred from May 2016 to December 2017. Sample of 18 patients with venous ulcer, who met the inclusion criteria. The participants attended weekly for 12 weeks to the outpatient clinic for nursing consultation and dressing change, with application of the plasma rich in growth factors (PRGF) for each 15 days. The PRGF preparation used the single- centrifugation technique and calcium gluconate as a platelet activator. Realization of platelet count and identification of growth factors in PRGF used in treatment. Platelet counting and identification of growth factors in the PRGF used in the treatment. Results: Homogeneous sample regarding socioeconomic and clinical variables, with predominance of the elderly, male gender, incomplete primary education and income between 1 and 2 minimum wages. A PRGF with a low platelet count, median of 122 x 103 mm3 platelets, but with the main platelet growth factors involved in the healing (PDGF-AB, PDGF-BB, TGF-ß, VEGF, EGF and FGF2). There was a high variability in platelet counts and in the concentration of growth factors, with a strong and significant correlation between the amount of platelets and the growth factors PDGF-AB and PDGF-BB. The means of each growth factor were 1.52 ng / ml for PDGF-AB, 1.38 ng / ml for PDGF-BB, 1.40 ng / ml for TGF-ß, 0.99 ng / ml for VEGF, 1.57 ng / ml for EGF and 1.04 ng / ml for FGF2. The initial mean size of the ulcers in this study was 29.6 ± 23.9 / cm2 and the percentage mean reduction in area after 12 weeks of treatment was 46.2%. The ulcer size after treatment was significantly smaller than the initial ulcer size (Wilcoxon p-value = 0.001). However, the area of ulcer reduction over the 12-week period did not correlate with growth factor concentrations in PRGF. The percentage of epitalization tissue increased throughout the study period with a significant increase at the end of 12 treatments (mean = 58.1%) and devitalized tissue decreased throughout the study period with a significant reduction at the end of 12 weeks (mean = 11%). At the end of 12 weeks there was a significant improvement in the type of exudate in the ulcers and a significant decrease in the amount of exudate in the ulcers. Conclusion: In this study, the null hypothesis was confirmed that the concentration of growth factors present in PRGF did not present statistically significant relationship with the reduction of venous ulcers area.

Objetivo general: Analizar las propiedades del plasma rico en factor de crecimiento autólogo (PRGF) para tratar pacientes con úlcera venosa. Método: Estudio cuasi experimental realizado en un hospital universitario. Datos recolectados entre mayo de 2016 y diciembre de 2017. Muestra compuesta por 18 pacientes con úlcera venosa que cumplieron los criterios de inclusión. Los participantes asistieron semanalmente, durante 12 semanas, a la clínica ambulatoria para consulta de enfermería y cambio de apósito, con aplicación de plasma rico en factor de crecimiento (PRGF) en frecuencia bisemanal. La preparación de PRGF utilizó la técnica de centrifugación; se empleó gluconato de calcio como activador plaquetario. Se efectuó recuento de plaquetas e identificación de los factores de crecimiento en el PRGF utilizado en el tratamiento. Resultados: Muestra homogénea en sus variables socioeconómicas y clínicas, con predominio de ancianos, varones, estudios primarios incompletos, con ingresos de entre 1 y 2 salarios mínimos. Se obtuvo un PRGF con bajo recuento de plaquetas, con mediana de 122 x 103 mm3 de plaquetas, aunque con importantes factores de crecimiento plaquetario involucrados en la curación (PDGF-AB, PDGF-BB, TGF-ß, VEGF, EGF y FGF2). Existió marcada variabilidad en el recuento plaquetario y en la concentración del factor de crecimiento, con marcada y significativa correlación entre la cantidad de plaquetas y factores de crecimiento PDGF-AB y PDGF-BB. Los promedios de cada factor de crecimiento fueron 1.52 ng / ml para PDGF-AB, 1.38 ng / ml para PDGF-BB, 1.40 ng / ml para TGF-ß, 0.99 ng / ml para VEGF, 1,57 ng / ml para EGF y 1,04 ng / ml para FGF2. El tamaño inicial promedio de las úlceras observadas en este estudio fue de 29,6 ± 23,9 / cm2, y la reducción porcentual media en el área luego de 12 semanas de tratamiento fue del 46,2%. El tamaño de las úlceras luego del tratamiento resultó ser significativamente inferior a su tamaño inicial (p-valor del test de Wilcoxon igual a 0,001). Sin embargo, la reducción del área de las úlceras, durante el período de 12 semanas, no se correlacionó con las concentraciones de los factores de crecimiento en el PRGF. El porcentaje de tejido epitelial aumentó durante todo el período del estudio, con un aumento significativo final en 12 tratamientos (media = 58,1%). El tejido desvitalizado disminuyó a lo largo del estudio, con reducción significativa luego de 12 semanas (promedio = 11%). Finalizadas las 12 semanas, hubo mejora significativa en el tipo de exudado de las úlceras y disminución significativa de la cantidad de exudado de las úlceras. Conclusión: En este estudio, se confirmó la hipótesis nula en que la concentración de los factores de crecimiento presentes en el PRGF no presentaba una relación estadísticamente significativa con la reducción del área de las úlceras venosas.

Modulation of host cell signaling pathways as a therapeutic approach in periodontal disease

Recently, new treatment approaches have been developed to target the host component of periodontal disease. This review aims at providing updated information on host-modulating therapies, focusing on treatment strategies for inhibiting signal transduction pathways involved in inflammation. Pharmacological inhibitors of MAPK, NFκB and JAK/STAT pathways are being developed to manage rheumatoid arthritis, periodontal disease and other inflammatory diseases. Through these agents, inflammatory mediators can be inhibited at cell signaling level, interfering on transcription factors activation and inflammatory gene expression. Although these drugs offer great potential to modulate host response, their main limitations are lack of specificity and developments of side effects. After overcoming these limitations, adjunctive host modulating drugs will provide new therapeutic strategies for periodontal treatment.