RESUMEN
The objective of this study was to observe the acute cytotoxic effects of hematoporphyrin monomethyl ether sonodynamic therapy (HMME-SDT) on hypertrophic scar fibroblasts of rabbit ears. We first assessed the effects of different irradiation times and HMME concentrations on the survival of hypertrophic scar fibroblasts using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay to determine the optimum irradiation time and HMME concentration. The hypertrophic scar fibroblast cell suspensions of the rabbit ears were divided into four groups, the survival rates were detected using the MTT assay, and the type of cell death was detected by Annexin V/propidium iodide (PI) double staining flow cytometry. Our results showed that HMME-SDT significantly reduced the viability of hypertrophic scar fibroblasts of rabbit ears at ultrasonic irradiation times of 30, 60, and 90 s, but not 10 s (P < 0.05). HMME alone had no significant effect on the cell survival rate at any irradiation time (P > 0.05). In contrast, the cell survival rate was significantly decreased at an irradiation time of 10 s and HMME concentrations of 20 and 50 µg/mL (P < 0.05). Furthermore, Annexin V/PI double staining showed necrosis and apoptosis of the hypertrophic scar fibroblasts. Given our results, HMME might be an effective sound-sensitive agent for SDT as it has a significant lethal effect on hypertrophic scar fibroblasts of rabbit ear cultured in vitro. HMME-SDT may therefore provide a new method for the treatment of hypertrophic scar formation.
Asunto(s)
Cicatriz Hipertrófica/diagnóstico por imagen , Oído/diagnóstico por imagen , Oído/patología , Hematoporfirinas/uso terapéutico , Terapia por Ultrasonido/métodos , Animales , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cicatriz Hipertrófica/cirugía , Fibroblastos/diagnóstico por imagen , Fibroblastos/patología , Conejos , Distribución Aleatoria , Especies Reactivas de Oxígeno/uso terapéutico , UltrasonografíaRESUMEN
Wood formation occurs via cell division, primary cell wall and secondary wall formation, and programmed cell death in the vascular cambium. Transcriptional profiling of secondary xylem differentiation is essential for understanding the molecular mechanisms underlying wood formation. Differential gene expression in secondary xylem differentiation of Populus has been previously investigated using cDNA microarray analysis. However, little is known about the molecular mechanisms from a genome-wide perspective. In this study, the Affymetrix poplar genome chips containing 61,413 probes were used to investigate the changes in the transcriptome during secondary xylem differentiation in Chinese white poplar (Populus tomentosa). Two xylem tissues (newly formed and lignified) were sampled for genome-wide transcriptional profiling. In total, 6843 genes (~11%) were identified with differential expression in the two xylem tissues. Many genes involved in cell division, primary wall modification, and cellulose synthesis were preferentially expressed in the newly formed xylem. In contrast, many genes, including 4-coumarate:cinnamate-4-hydroxylase (C4H), 4-coumarate:CoA ligase (4CL), cinnamyl alcohol dehydrogenase (CAD), and caffeoyl CoA 3-O-methyltransferase (CCoAOMT), associated with lignin biosynthesis were more transcribed in the lignified xylem. The two xylem tissues also showed differential expression of genes related to various hormones; thus, the secondary xylem differentiation could be regulated by hormone signaling. Furthermore, many transcription factor genes were preferentially expressed in the lignified xylem, suggesting that wood lignification involves extensive transcription regulation. The genome-wide transcriptional profiling of secondary xylem differentiation could provide additional insights into the molecular basis of wood formation in poplar species.