A role for the immune system-released activating agent (ISRAA) in the ontogenetic development of brain astrocytes
Fig 2
Embryonic brain astrocyte proliferation and differentiation and illustration of ISRAA activity on these events.
Spontaneous and ISRAA induced cell proliferation and differentiation were assessed by MTT and by morphological observation and determination. Astrocytes were prepared and cultured as described in the Materials and Methods section. Non-stimulated astrocytes from E7 showed high proliferation (Fig 2A; black bar) and no clear differentiation (represented in Fig 2E). E21 astrocytes showed lower proliferation (Fig 2A; black bar) with clear cell differentiation (represented in Fig 2F). Stimulation of E7 with recombinant ISRAA resulted in increased cellular proliferation (Fig 2A; grey bar) and also represented in Fig 2G. In response to ISRAA stimulation, E21 showed less proliferation (Fig 2A; grey bar) and well differentiated cells (represented in Fig 2H). Pre-incubation with anti-ISRAA antibody abrogated the proliferative response in E7 and induced E21 to proliferate (Fig 2B). Intrinsic ISRAA expression in embryonic mouse brain astrocytes was illustrated by immunohistochemistry. As exemplified in Fig 2C, E7 demonstrates few faint cells stained for ISRAA, while E21 showed high numbers of positively and strongly stained cells for ISRAA (exemplified in Fig 2D). Experiments were conducted twice with alike findings. Pictures were gathered via bright field microscopy (x630). Bars denote the means ±SD of eight cultures (***p<0.05).