Publications by authors named "P Ortega-Saenz"
Article Synopsis
- Loss of heterozygosity for defective alleles of the SDH enzyme can lead to paragangliomas, a type of tumor originating in neuroendocrine cells in humans.
- Researchers created mouse models with conditional loss of the SDHC subunit in early development, hypothesizing it would induce paraganglioma in chromaffin cells.
- Instead of tumors, mice showed developmental defects like gait anomalies and fur discoloration, indicating neural crest cell dysfunction without tumor formation, suggesting differences between human and mouse responses to SDH loss.
Article Synopsis
- The gene encodes a G-protein-coupled olfactory receptor, Olfr78, which is expressed in carotid body glomus cells that help regulate breathing in response to low oxygen levels.
- Despite proposals suggesting that Olfr78 acts as a lactate receptor involved in the hypoxic ventilatory response, research indicates it may not be physiologically relevant, as knockout mice exhibit normal breathing responses.
- Conditional knockout studies reveal that while Olfr78 is not essential for oxygen sensing, it plays a crucial role in the maturation and function of glomus cells, affecting their molecular and neurosecretory activity.
Acute oxygen (O) sensing and adaptation to hypoxia are essential for physiological homeostasis. The prototypical acute O sensing organ is the carotid body, which contains chemosensory glomus cells expressing O-sensitive K channels. Inhibition of these channels during hypoxia leads to cell depolarization, transmitter release, and activation of afferent sensory fibers terminating in the brain stem respiratory and autonomic centers.
View Article and Find Full Text PDFAntiparkinsonian carotid body (CB) cell therapy has been proven to be effective in rodent and nonhuman primate models of Parkinson's disease (PD), exerting trophic protection and restoration of the dopaminergic nigrostriatal pathway. These neurotrophic actions are mediated through the release of high levels of glial-cell-line-derived neurotrophic factor (GDNF) by the CB transplant. Pilot clinical trials have also shown that CB autotransplantation can improve motor symptoms in PD patients, although its effectiveness is affected by the scarcity of the grafted tissue.
View Article and Find Full Text PDFThe hypoxic ventilatory response (HVR) is a life-saving reflex, triggered by the activation of chemoreceptor glomus cells in the carotid body (CB) connected with the brainstem respiratory center. The molecular mechanisms underlying glomus cell acute oxygen (O) sensing are unclear. Genetic disruption of mitochondrial complex I (MCI) selectively abolishes the HVR and glomus cell responsiveness to hypoxia.
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