Effect of Nutrient Availability on Progenitor Cells in Zebrafish (Danio Rerio)

Abstract

In zebrafish brains, populations of continuously proliferating cells are present during an entire life span. Under normal conditions, stem cells give rise to rapidly proliferating progenitors that quickly exit the cell cycle and differentiate. Hence fish are favorable models to study what regulates postembryonic neurogenesis. The aim of this study was to determine if optic tectum (OT) cell proliferation is halted during nutritional deprivation (ND) and whether or not it can be restored with refeeding. We examined the effect of ND on the proliferation of Neuroepithelial/Ependymal Progenitor cell (NeEPC) and transitory-amplifying progenitors (TAPs). Following ND, no PCNA immunostaining was found in OT of starved fish, while positive cell populations of PCNA positive progenitors are found at its periphery in control fish. This indicated that active proliferation stopped. To label retaining progenitor cells, BrdU was applied and a chase-period was accompanied by ND. Positive NeEPCs were detected in the external tectum marginal zone of starved fish suggesting that these progenitors are relatively immune to ND. Moreover in the internal tectum marginal zone labeled retaining cells were observed leaving the possibility that some arrested TAPs were present to readily restart proliferation when nutrition was returned. Our results suggest that neurogenesis was maintained during ND and that a normal proliferative situation was recovered after refeeding. We point to the mTOR pathway as a necessary pathway in progenitors to regulate their mitosis activity. Thus, this study highlights mechanisms involved in neural stem and progenitor cell homeostatic maintenance in an adverse situation. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 26-38, 2017.

Constitutive Neurogenesis and Neuronal Plasticity in the Adult Cerebellum and Brainstem of Rainbow Trout, Oncorhynchus mykiss

“…The decrease in mitotic activity coincides in time with the decrease in DC labeling [ 52 ]. A growing body of evidence suggests that aNSPCs are sensitive to endocrine signals [ 54 ], specific sensory modulation [ 55 ], social interactions [ 56 ], nutrient availability [ 57 ], and neurotrauma [ 8 , 9 , 13 , 20 , 22 , 58 ]. Depending on these factors, different populations of stem cells and progenitor cells can change their cycles of activity.…”

Postembryonic Fish Brain Proliferation Zones Exhibit Neuroepithelial-Type Gene Expression Profile

“…The genes overexpressed in medaka OT NE cells and in the VZ of the cortex in human and mouse embryos included Hes 5 and Yap 1 , known to stimulate proliferation and to inhibit the differentiation of NE cells . Another gene of interest is nr2e1—Nuclear receptor TLX or tailless in Drosophila melanogaster .…”

Uncovering the spectrum of adult zebrafish neural stem cell cycle regulators

“…Chronic hyperglycemia in adult zebrafish, for instance, was reported to impair homeostatic neurogenesis in the telencephalon, midbrain, and cerebellum, while also having a pro-inflammatory and oxidative stress effect ( Dorsemans et al, 2017 ; Stankiewicz et al, 2017 ; Ghaddar et al, 2021 ). Conversely, 10 weeks of reduced food intake appears to be insufficient to alter aNSPC activity in the forebrain ( Arslan-Ergul et al, 2016 ), but a 5 week starvation is adequate to decrease aNSPC proliferation in the optic tectum ( Benítez-Santana et al, 2016 ). Additional niche-wide studies focusing on food type, nutrient composition, and feeding frequency undoubtedly would be beneficial to determine if distinct aNSPC populations are differentially affected and how this relates to changes in cell metabolism.…”