Bruna Marcele Martins de Oliveira

Reproductive Stem Cell Differentiation Extracellular Matrix, Tissue Microenvironment, and Growth Factors Direct the Mesenchymal Stem Cell Lineage Commitment

The mesenchymal stem cells (MSCs) have awakened interest in regenerative medicine due to its high capability to proliferate and differentiate in multiple specialized lineages under defined conditions. The reproductive system is considered a valuable source of MSCs, which needs further investigations. Many factors have been reported as critical for these cell lineage specification and determination. In this review, we discuss the main effects of extracellular matrix or tissue environment and growth factors in the cell lineage commitment, including the reproductive stem cells. The MSCs responses to culture medium stimuli or to soluble factors probably occur through several intracellular activation pathways. However, the molecular mechanisms in which the cells respond to these mechanical or chemical perturbations remain elusive. Recent findings suggest a synergic effect of microenvironment and soluble cell culture factors affecting cell differentiation. For future applications in cell therapy, protocols of reproductive MSCs differentiation must be established.

An Efficient Technique to Detect Sperm Reactive Oxygen Species: The CellRox Deep Red ® Fluorescent Probe

Heat stress and testicular traumas increase sperm Reactive Oxygen Species (ROS) resulting in Oxidative Stress (OS) and injury of sperm. The fluorescent probe CellROX Deep Red® is not already used to detect ROS in spermatozoa. On this way, this study aims to evaluate its efficiency in detecting ROS in ram sperm. For that, it was used ejaculates from rams performing the in vitro induction of sperm OS in T0, T50 and T100. T0 was semen sample that was not submitted to OS induction, T50 was 50% induced to OS induction and T100 was entire submitted to OS induction. The production of ROS was detected by CellROX Deep Red®. Data polynomial regression analysis was performed and the result of determination coefficient was 0.728. Besides, sixteen rams were submitted to scrotal insulation during 72 hours performing the in vivo induction of OS sperm. Analyses of sperm motility, morphology, DNA fragmentation and ROS (detected by CellROX Deep Red®) were done two times before the scrotal insulation and two times afterwards. Data analysis of variance was performed from the periods (before x after) and it is observed that after scrotal insulation the total and progressive motility decrease (p<0.05) and total and major sperm defects and sperm DNA fragmentation increase (p<0.05). Moreover, after insulation, it was observed increase (p<0.05) in sperm showing moderate and intense OS. Thus, it is possible to conclude that CellROX® fluorescent probe is able to detect ROS production in ram sperm by in vitro and in vivo induction being a new technique to detect sperm OS.