Differentiation of Chromaffin Progenitor Cells to Dopaminergic Neurons

Abstract

The differentiation of dopamine-producing neurons from chromaffin progenitors might represent a new valuable source for replacement therapies in Parkinson's disease. However, characterization of their differentiation potential is an important prerequisite for efficient engraftment. Based on our previous studies on isolation and characterization of chromaffin progenitors from adult adrenals, this study investigates their potential to produce dopaminergic neurons and means to enhance their dopaminergic differentiation. Chromaffin progenitors grown in sphere culture showed an increased expression of nestin and Mash1, indicating an increase of the progenitor subset. Proneurogenic culture conditions induced the differentiation into neurons positive for neural markers b-III-tubulin, MAP2, and TH accompanied by a decrease of Mash1 and nestin. Furthermore, Notch2 expression decreased concomitantly with a downregulation of downstream effectors Hes1 and Hes5 responsible for self-renewal and proliferation maintenance of progenitor cells. Chromaffin progenitor-derived neurons secreted dopamine upon stimulation by potassium. Strikingly, treatment of differentiating cells with retinoic and ascorbic acid resulted in a twofold increase of dopamine secretion while norepinephrine and epinephrine were decreased. Initiation of dopamine synthesis and neural maturation is controlled by Pitx3 and Nurr1. Both Pitx3 and Nurr1 were identified in differentiating chromaffin progenitors. Along with the gained dopaminergic function, electrophysiology revealed features of mature neurons, such as sodium channels and the capability to fire multiple action potentials. In summary, this study elucidates the capacity of chromaffin progenitor cells to generate functional dopaminergic neurons, indicating their potential use in cell replacement therapies.

Adrenal cortical and chromaffin stem cells: Is there a common progeny related to stress adaptation?

“…Since we have previously shown that human and bovine medullary progenitors express Nestin (Chung et al, 2009;Santana et al, 2012;Vukicevic et al, 2012), we were able to take advantage of the Nestin-GFP mouse model, where enhanced green fluorescent protein is expressed under the regulation of the Nes gene regulatory element (Mignone et al, 2004). In this mouse we detected Nestin-positive cells through expression of GFP, both in the adrenal medulla and cortex ( Fig.…”

“…Due to their favorable properties, chromospheres could represent a new and promising source for cell replacement therapy in Parkinson´s disease as a significantly higher population of chromospherederived cells has been shown to acquire a dopaminergic phenotype compared to chromaffin cells (Boronat-Garcia et al, 2016;Vukicevic et al, 2012).…”

“…5 differentiating into cells of the chromaffin and neural lineages (Chung et al, 2009;Santana et al, 2012;Vukicevic et al, 2012).…”

Impaired adrenal medullary function in a mouse model of depression induced by unpredictable chronic stress

“…Additionally, we can suggest that an increase in the number of mature chromaffin cells, due to chromaffin progenitor cell differentiation, might also be a mechanism to improve adrenal medullary function. Sox9 and Notch1 are important to maintain the cells in an undifferentiated state (Scott et al, 2010), and their downregulation induce cell differentiation into different neural crest cell derivatives (Wang and Sul, 2009), including sympathoadrenal progenitors (Unsicker et al, 2013;Vukicevic et al, 2012). Moreover, Mash1 and Phox2b are crucial for the induction of catecholamine biosynthetic enzymes during chromaffin cell differentiation (Unsicker et al, 2013).…”

Transplantation of bovine adrenocortical cells encapsulated in alginate

“…BACs and chromaffin cells were isolated from bovine adrenals of freshly slaughtered 1-3-y-old cattle by collagenase digestion, as previously described (17,31,32).…”