Project description:The carotid body is a chemoreceptor that senses decreases in blood oxygen to increase breathing in hypoxia. To look for candidate oxygen sensors in the carotid body, we compared the gene expression of the carotid body to the adrenal medulla, a similar tissue that does not have oxygen sensitivity in adults.
Project description:The carotid body is a chemoreceptor that senses decreases in blood oxygen to increase breathing in hypoxia. To look for candidate oxygen sensors in the carotid body, we compared the gene expression of the carotid body to the adrenal medulla, a similar tissue that does not have oxygen sensitivity in adults. For each sample, we pooled 18 carotid bodies or 10 adrenal medullas from 10 adult mice. Group numbers designate the same cohort of animals.
Project description:The carotid body is a chemoreceptor that senses decreases in blood oxygen to increase breathing in hypoxia. To look for candidate oxygen sensors in the carotid body, we compared the gene expression of the carotid body to the adrenal medulla, a similar tissue that does not have oxygen sensitivity in adults.
Project description:The carotid body is a chemoreceptor that senses decreases in blood oxygen to increase breathing in hypoxia. To look for candidate oxygen sensors in the carotid body, we compared the gene expression of the carotid body to the adrenal medulla, a similar tissue that does not have oxygen sensitivity in adults. For each sample, we pooled 18 carotid bodies and 10 adrenal medullas from 10 adult mice.
Project description:Hypoxia-inducible factors (HIF) 2α and 1α are the major oxygen-sensing molecules in eukaryotic cells. HIF2α has been pathogenically linked to paraganglioma and pheochromocytoma (PPGL) arising in sympathetic paraganglia or the adrenal medulla (AM), respectively. However, its involvement in the pathogenesis of paraganglioma arising in the carotid body (CB) or other parasympathetic ganglia in the head and neck (HNPGL) remains to be defined. Here, we retrospectively analyzed HIF2α by immunohistochemistry in 62 PPGL/HNPGL and human CB and AM, and comprehensively evaluated the HIF-related transcriptome of 202 published PPGL/HNPGL. We report that HIF2α is barely detected in the AM, but accumulates at high levels in PPGL, mostly (but not exclusively) in those with loss-of-function mutations in VHL and genes encoding components of the succinate dehydrogenase (SDH) complex. This is associated with upregulation of EPAS1 and the HIF2α-regulated genes COX4I2 and ADORA2A. In contrast, HIF2α and HIF2α-regulated genes are highly expressed in CB and HNPGL, irrespective of VHL and SDH dysfunctions. We also found that HIF2α and HIF1α protein expressions are not correlated in PPGL nor HNPGL. In addition, HIF1α-target genes are almost exclusively overexpressed in VHL-mutated HNPGL/PPGL. Collectively, the data suggest that involvement of HIF2α in the physiology and tumor pathology of human paraganglia is organ-of-origin-dependent and HIF1α-independent.