Limits...
Immunohistochemical characterization of the chemosensory pulmonary neuroepithelial bodies in the naked mole-rat reveals a unique adaptive phenotype.

Pan J, Park TJ, Cutz E, Yeger H - PLoS ONE (2014)

Bottom Line: NEBs produce the bioactive amine, serotonin (5-HT), and a variety of peptides with multiple effects on lung physiology and other organ systems.The chemosensory NEBs of this species were characterized and compared to those of the conventional Wistar rat (WR) to identify similarities and differences that could explain the NMR's adaptability to environments.However, we found the following differences: 1) NEBs in both neonatal and adult NMR lungs were significantly larger and more numerous as compared to WR; 2) NEBs in NMR had a more variable compact cell organization and exhibited significant differences in the expression of adhesion proteins; 3) NMR NEBs showed a significantly greater ratio of 5-HT positive cells with an abundance of 5-HT; 4) NEBs in NMR expressed the proliferating cell nuclear antigen (PCNA) and the neurogenic gene (MASH1) indicating active proliferation and a state of persistent differentiation.

View Article: PubMed Central - PubMed

Affiliation: Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; Physiology and Experimental Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.

ABSTRACT
The pulmonary neuroepithelial bodies (NEBs) constitute polymodal airway chemosensors for monitoring and signaling ambient gas concentrations (pO2, pCO2/H+) via complex innervation to the brain stem controlling breathing. NEBs produce the bioactive amine, serotonin (5-HT), and a variety of peptides with multiple effects on lung physiology and other organ systems. NEBs in mammals appear prominent and numerous during fetal and neonatal periods, and decline in the post-natal period suggesting an important role during perinatal adaptation. The naked mole-rat (NMR), Heterocephalus glaber, has adapted to the extreme environmental conditions of living in subterranean burrows in large colonies (up to 300 colony mates). The crowded, unventilated burrows are environments of severe hypoxia and hypercapnia. However, NMRs adjust readily to above ground conditions. The chemosensory NEBs of this species were characterized and compared to those of the conventional Wistar rat (WR) to identify similarities and differences that could explain the NMR's adaptability to environments. A multilabel immunohistochemical analysis combined with confocal microscopy revealed that the expression patterns of amine, peptide, neuroendocrine, innervation markers and chemosensor component proteins in NEBs of NMR were similar to that of WR. However, we found the following differences: 1) NEBs in both neonatal and adult NMR lungs were significantly larger and more numerous as compared to WR; 2) NEBs in NMR had a more variable compact cell organization and exhibited significant differences in the expression of adhesion proteins; 3) NMR NEBs showed a significantly greater ratio of 5-HT positive cells with an abundance of 5-HT; 4) NEBs in NMR expressed the proliferating cell nuclear antigen (PCNA) and the neurogenic gene (MASH1) indicating active proliferation and a state of persistent differentiation. Taken together our findings suggest that NEBs in lungs of NMR are in a hyperactive, functional and developmental state, reminiscent of a persistent fetal state that extends postnatally.

Show MeSH

Related in: MedlinePlus

HIF1α and HIF2α in cultured NEBs of NMR.Primary cultures of NMR lungs were established short term and immunostained for 5-HT to identify NEB cells and coordinately for HIF1α and HIF2α. Note the strong nuclear staining for HIF1α (top) and mostly cytoplasmic staining for HIF2α (bottom). Note also that not all cells immunostain for these hypoxia sensitive markers suggesting different physiological states for cells within the NEBs and potentially different sensory capabilities.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4237365&req=5

pone-0112623-g006: HIF1α and HIF2α in cultured NEBs of NMR.Primary cultures of NMR lungs were established short term and immunostained for 5-HT to identify NEB cells and coordinately for HIF1α and HIF2α. Note the strong nuclear staining for HIF1α (top) and mostly cytoplasmic staining for HIF2α (bottom). Note also that not all cells immunostain for these hypoxia sensitive markers suggesting different physiological states for cells within the NEBs and potentially different sensory capabilities.

Mentions: This idea of specialization within the NMR NEB cells begged the question whether these cells were equally responsive to hypoxia. We therefore stained the NMR NEBs for expression of HIF1α and HIF2α, key hypoxia inducible proteins that mediate hypoxia driven transcriptional events in most cells. For these studies we examined both lung sections and primary cultures where moderate hypoxia often prevails under the relatively deep zone of medium. The in vitro culture of NMR tissues, other than fibroblasts, is currently under development so we will report on this aspect subsequently [manuscript in preparation]. Our findings here using short term primary cultures (Figure 6) reveal that little if any expression of HIFs was observed in native lung (not shown). However, in primary cultures a subpopulation of 5-HT positive NEB cells were strongly nuclear positive for HIF1α while other 5-HT positive cells were negative (Figure 6). In comparison, a subpopulation of NMR NEB cells were HIF2α expressing but mainly cytoplasmic. This differential staining suggests that in vitro HIF1α is activated transcriptionally but not overtly for HIF2α. These observations again suggest heterogeneity amongst the NMR NEB cells, and potentially a more complex neuroendocrine organ. To further examine this plasticity we examined the developmental state of the NMR NEBs.


Immunohistochemical characterization of the chemosensory pulmonary neuroepithelial bodies in the naked mole-rat reveals a unique adaptive phenotype.

Pan J, Park TJ, Cutz E, Yeger H - PLoS ONE (2014)

HIF1α and HIF2α in cultured NEBs of NMR.Primary cultures of NMR lungs were established short term and immunostained for 5-HT to identify NEB cells and coordinately for HIF1α and HIF2α. Note the strong nuclear staining for HIF1α (top) and mostly cytoplasmic staining for HIF2α (bottom). Note also that not all cells immunostain for these hypoxia sensitive markers suggesting different physiological states for cells within the NEBs and potentially different sensory capabilities.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4237365&req=5

pone-0112623-g006: HIF1α and HIF2α in cultured NEBs of NMR.Primary cultures of NMR lungs were established short term and immunostained for 5-HT to identify NEB cells and coordinately for HIF1α and HIF2α. Note the strong nuclear staining for HIF1α (top) and mostly cytoplasmic staining for HIF2α (bottom). Note also that not all cells immunostain for these hypoxia sensitive markers suggesting different physiological states for cells within the NEBs and potentially different sensory capabilities.
Mentions: This idea of specialization within the NMR NEB cells begged the question whether these cells were equally responsive to hypoxia. We therefore stained the NMR NEBs for expression of HIF1α and HIF2α, key hypoxia inducible proteins that mediate hypoxia driven transcriptional events in most cells. For these studies we examined both lung sections and primary cultures where moderate hypoxia often prevails under the relatively deep zone of medium. The in vitro culture of NMR tissues, other than fibroblasts, is currently under development so we will report on this aspect subsequently [manuscript in preparation]. Our findings here using short term primary cultures (Figure 6) reveal that little if any expression of HIFs was observed in native lung (not shown). However, in primary cultures a subpopulation of 5-HT positive NEB cells were strongly nuclear positive for HIF1α while other 5-HT positive cells were negative (Figure 6). In comparison, a subpopulation of NMR NEB cells were HIF2α expressing but mainly cytoplasmic. This differential staining suggests that in vitro HIF1α is activated transcriptionally but not overtly for HIF2α. These observations again suggest heterogeneity amongst the NMR NEB cells, and potentially a more complex neuroendocrine organ. To further examine this plasticity we examined the developmental state of the NMR NEBs.

Bottom Line: NEBs produce the bioactive amine, serotonin (5-HT), and a variety of peptides with multiple effects on lung physiology and other organ systems.The chemosensory NEBs of this species were characterized and compared to those of the conventional Wistar rat (WR) to identify similarities and differences that could explain the NMR's adaptability to environments.However, we found the following differences: 1) NEBs in both neonatal and adult NMR lungs were significantly larger and more numerous as compared to WR; 2) NEBs in NMR had a more variable compact cell organization and exhibited significant differences in the expression of adhesion proteins; 3) NMR NEBs showed a significantly greater ratio of 5-HT positive cells with an abundance of 5-HT; 4) NEBs in NMR expressed the proliferating cell nuclear antigen (PCNA) and the neurogenic gene (MASH1) indicating active proliferation and a state of persistent differentiation.

View Article: PubMed Central - PubMed

Affiliation: Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; Physiology and Experimental Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.

ABSTRACT
The pulmonary neuroepithelial bodies (NEBs) constitute polymodal airway chemosensors for monitoring and signaling ambient gas concentrations (pO2, pCO2/H+) via complex innervation to the brain stem controlling breathing. NEBs produce the bioactive amine, serotonin (5-HT), and a variety of peptides with multiple effects on lung physiology and other organ systems. NEBs in mammals appear prominent and numerous during fetal and neonatal periods, and decline in the post-natal period suggesting an important role during perinatal adaptation. The naked mole-rat (NMR), Heterocephalus glaber, has adapted to the extreme environmental conditions of living in subterranean burrows in large colonies (up to 300 colony mates). The crowded, unventilated burrows are environments of severe hypoxia and hypercapnia. However, NMRs adjust readily to above ground conditions. The chemosensory NEBs of this species were characterized and compared to those of the conventional Wistar rat (WR) to identify similarities and differences that could explain the NMR's adaptability to environments. A multilabel immunohistochemical analysis combined with confocal microscopy revealed that the expression patterns of amine, peptide, neuroendocrine, innervation markers and chemosensor component proteins in NEBs of NMR were similar to that of WR. However, we found the following differences: 1) NEBs in both neonatal and adult NMR lungs were significantly larger and more numerous as compared to WR; 2) NEBs in NMR had a more variable compact cell organization and exhibited significant differences in the expression of adhesion proteins; 3) NMR NEBs showed a significantly greater ratio of 5-HT positive cells with an abundance of 5-HT; 4) NEBs in NMR expressed the proliferating cell nuclear antigen (PCNA) and the neurogenic gene (MASH1) indicating active proliferation and a state of persistent differentiation. Taken together our findings suggest that NEBs in lungs of NMR are in a hyperactive, functional and developmental state, reminiscent of a persistent fetal state that extends postnatally.

Show MeSH
Related in: MedlinePlus