Anti-PHOX2B (center region) polyclonal antibody

Congenital central hypoventilation syndrome (CCHS) is a rare, lifelong disorder of the breathing centre, resulting from a mutation of the PHOX2B gene. CCHS typically manifests in newborns with alveolar hypoventilation/apnea during sleep. Clinical severity of hypoventilation and a risk of associated conditions (Hirschsprung disease, tumors of neural crest and autonomic nervous system dysfunction) depend on the type of the PHOX28 gene mutation. Approximately 90% of individuals with the CCHS phenotype are heterozygous for the PARMs-type mutation (Polyalanine Repeat Expansion Mutations), the remaining 10% of patients express heterozygous missense-, nonsense- or frameshift-type mutation (non-PARMs). Significant hypoventilation leading to severe hypercapnia and hypoxemia was observed in two of our newborns with proved CCHS during the first week after birth. Following a very short period of mechanical ventilation, we succeeded in maintaining physiological blood gases with noninvasive ventilation during sleep. With modern techniques for home ventilation and follow up at specialized centres, children with CCHS have good long-term prognosis and low mortality.

The development of the taste system relies on the coordinated regulation of cues that direct the simultaneous development of both peripheral taste organs and innervating sensory ganglia, but the underlying mechanisms remain poorly understood. In this study, we describe a novel, biphasic function for glial cell line-derived neurotrophic factor (GDNF) in the development and subsequent diversification of chemosensory neurons within the geniculate ganglion (GG). GDNF, acting through the receptor tyrosine kinase Ret, regulates the expression of the chemosensory fate determinant Phox2b early in GG development. Ret(-/-) mice, but not Ret(fx/fx); Phox2b-Cre mice, display a profound loss of Phox2b expression with subsequent chemosensory innervation deficits, indicating that Ret is required for the initial amplification of Phox2b expression but not its maintenance. Ret expression is extinguished perinatally but reemerges postnatally in a subpopulation of large-diameter GG neurons expressing the mechanoreceptor marker NF200 and the GDNF coreceptor GFR alpha 1. Intriguingly, we observed that ablation of these neurons in adult Ret-Cre/ERT2; Rosa26(LSL-DTA) mice caused a specific loss of tactile, but not chemical or thermal, electrophysiological responses. Overall, the GDNF-Ret pathway exerts two critical and distinct functions in the peripheral taste system: embryonic chemosensory cell fate determination and the specification of lingual mechanoreceptors.