Heterogeneity of Cells Population and Secretome Profile of Differentiated Cells from E17 Rat Neural Progenitor Cells

Abstract

Conditioned medium has now gained increasing interest since the development of secretome-based therapy. Various types of cells have been studied as a source of the secretome. One of them is neural progenitor cells (NPCs). These are cells that capable of differentiating into neurons as well as glial cells. Indeed, the study on NPCs has risen in the last few decades, but the study on the differentiated cells has not clearly described. The most common procedures that widely used to get the conditioned medium is starvation. However, cell starvation may cause environmental stress and become an apoptotic trigger for the cells. In this study, we analyzed the effect of starvation on differentiated cells from E17 rat neural progenitor cells (NPCs) based on cells characteristics and secretome profile. We found that starvation decreased cells viability and affected the heterogeneity of the cell population. Astrocytes survived more under nutrient deprivation conditions, and the progenitor cells showed a higher tendency to differentiate to glial cells than neurons. Duration of starvation also influenced the secretome profile, alterations found in protein types and also their function in the biological process. During 24 hours of starvation, cells secreted proteins that were used to maintain cell growth, stimulate differentiation, and produce energy, but there were also proteins that identified and involved in autophagy activation. After 48 hours of starvation, astrocytes that became the dominant cells secreted proteins that try to keep protecting the remaining neurons.

Conditioned medium of E17 rat brain cells induced differentiation of primary colony of mice blastocyst into neuron-like cells

“…On the other hand, there were also proteins for the activation of autophagy and proteins secreted in response to microenvironmental stress. The cells cultured after long periods of starvation with the dominance of glial cells secreted proteins that act as neuroprotectors [ 11 ]. Hence, the conditioned medium from the cells cultured in serum-free conditions for 24 hours was used to test whether the conditioned medium would induce the differentiation of the primary colony of mice blastocyst.…”

“…On the other hand, the proliferation and neurogenesis of the cells in that zone responded well to the stimulation of combined extracellular factors, such as EGF, FGF2, PDGF, BMPs, noggin, prolactin, and erythropoietin [ 40 41 42 43 ]. The conditioned medium used in this study contained various proteins secreted from the cells that mediated the differentiation process because of its multiple growth factors and other secreted proteins [ 11 ].…”

“…All fetuses were removed and stored in a sterile, cold dissection solution (HBSS containing 0.3% glucose). The methods for isolating the neuronal cells and producing the conditioned medium were reported by Budiariati et al [ 11 ]. The conditioned medium used in this study was collected 24 hours after serum deprivation.…”

“…Related to the mechanism in which the conditioned medium had beneficial effects, some considerations are needed to choose the cells to produce conditioned medium because different types of cells will secrete different proteins or growth factors. There are many sources of the cells to produce or harvest conditioned medium, such as mesenchymal stem cells, neural stem cells, or adipocyte-derived stem cells [ 9 10 11 12 ].…”

“…Neural stem cell-conditioned medium has also been reported to inhibit cell apoptosis and have neuroprotective effects, making it a potential alternative and effective therapeutic intervention for ischemic stroke [ 10 ]. A previous study found that conditioned medium from a heterogeneous cell population of differentiated cells from E17 rat neural progenitor cells secreted proteins under starvation conditions that were used to maintain cell growth and stimulate differentiation [ 11 ]. The results of those studies were certainly very encouraging to open up future therapies for neurodegenerative diseases.…”