About this Research Topic
Trophic factors are best known for their important functions in nervous system development and physiology. This diverse group of signaling molecules carries out tremendous diversity of functions also outside the nervous system including guidance of development of several internal organs, regulation of specific stem and progenitor cell populations, control of metabolic fitness, reproduction and inflammation, and disease mechanisms such as cancer. On the other hand, in the nervous system they been shown to have effects on non-neuronal cells. For example, glial cell line-derived neurotrophic factor (GDNF) critically regulates kidney induction but its functions during renal differentiation are only about to be elucidated. Brain derived neurotrophic factor (BDNF) on the other hand is an important regulator of cardiac endothelium formation but whether it has physiological relevance for cardiac diseases is to be determined. Potential clinical importance of findings related to GDNF and spermatogonial stem cell self-renewal as well as ovarian follicle development are currently under active research and recent discoveries on trophic factors, such that growth/differentiation factor 15 (GDF15) has significant regulatory role in metabolism, open completely new therapeutic avenues for these molecules. Moreover, mesencephalic astrocyte-derived neurotrophic factor (MANF) being essential for pancreas differentiation shows unexpected potential in the control of current pandemic prevalence of diabetes, and in the mouse retina it has been suggested to mediate polarization of microglial cells. Also, the finding of GDNF to support dopamine neurons was fostered by earlier studies on regenerative effects of conditioned media from astrocytes.
Here we aim to review a wide range of non-neuronal functions of trophic factors. The overall layout is expected to give introductory overview to trophic factors, their action and signaling pathways activated upon ligand-receptor interaction. This is followed by thematic focus areas covering urogenital system, reproduction, metabolism and cancer. By this way the current research topic will advance holistic understanding of not only trophic factors but also function of the body as one entity.
Keywords: neurotrophic factor signaling, development, metabolism, cancer, immunology
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