Details for: CL0017000

Cell ID: CL0017000

Cell Name: pulmonary ionocyte

Description: An ionocyte that is part of the lung epithelium. The cells from this type are major sources of the CFTR protein in human and mice.

Selected Context(s): Overall

Gene Significance Landscape

Display Options
Score:
Display
Genes

Contexts:

Cell Significance Index (CSI) is uniquely calculated to reveal cell-specific gene markers. More info here

Significant Genes List

Genes with the highest and lowest Percentile Rank Scores (PRS) for pulmonary ionocyte within the selected context(s).

Gene ID: A unique numerical identifier for this specific gene.
Symbol: Shortened abbreviation or name that represents this gene.
Ensembl Gene ID: A unique identifier assigned by Ensembl for genomic data mapping.
CSI Score: A combined effect size and statistical significance measure for pulmonary ionocyte. Higher scores indicate a stronger, more significant difference in expression.
(Previously described as "Fold Change", but now represents Cliff's Delta × –log10(p).)

Gene ID: A unique numerical identifier for this specific gene.
Symbol: Shortened abbreviation or name that represents this gene.
Ensembl Gene ID: A unique identifier assigned by Ensembl for genomic data mapping.
CSI Score: A combined effect size and statistical significance measure for pulmonary ionocyte. Higher scores indicate a stronger, more significant difference in expression.
Average CSI: csi sum / gene count
Cell network configuration

This network visualizes key genes for pulmonary ionocyte. It primarily includes:
1. Top genes highly significant for this cell (Num. Top Cell Genes - based on the 'Min. CSI' setting).
2. Any additional specific 'Context Genes' you add below.
The final network is a combined view. Choose an Interaction Source (pathways or protein interactions) and optionally compare CSI scores with a Baseline Cell Type.

Maximum number of selected genes.
Select a context for the baseline cell.
Select a context for the target cell.
Target Cell for CSI:  pulmonary ionocyte (CL0017000)

 Legend
Nodes (Genes):
 Query Gene
Node size also reflects Target Cell CSI magnitude.
Node Color (Target Cell CSI in specific network):
 Very High
 High
 Medium
 Low
 Very Low
 N/A or Not Sig.
Edges (Interactions):
 STRING (Protein-Protein)
 ONTOLOGY (Shared Pathway)
 Colors vary by pathway category; default arrow applies.

Loading network (please wait)...

## Summary The [pulmonary ionocyte](/details-cell/CL0017000) is a rare epithelial cell type within the lung, described as a major source of the CFTR protein. Gene significance analysis reveals a highly specialized and metabolically active profile. The most specific markers, as indicated by their high `csi_z` scores, are overwhelmingly associated with mitochondrial energy production (e.g., [`CYTB`](/details-gene/4519), [`COX5B`](/details-gene/1329)) and proton/ion transport machinery (e.g., [`ATP6V0C`](/details-gene/527)). This suggests that the defining characteristic of the [pulmonary ionocyte](/details-cell/CL0017000) is its immense bioenergetic capacity, which is dedicated to fueling robust ion transport, a function critical for maintaining airway surface liquid homeostasis. ## Key Characteristics and Function **Overall**, the gene expression landscape of the [pulmonary ionocyte](/details-cell/CL0017000) points to a terminally differentiated cell with a singular, energy-intensive primary function. * **Metabolic Hyperactivity:** The top three most specific genes, [`CYTB`](/details-gene/4519), [`ATP6V0C`](/details-gene/527), and [`COX5B`](/details-gene/1329), are all integral to cellular energetics. [`CYTB`](/details-gene/4519) and [`COX5B`](/details-gene/1329) are core components of the mitochondrial electron transport chain, essential for aerobic respiration ([Link](https://doi.org/10.1038/290457a0)). The high specificity of [`PPARGC1A`](/details-gene/10891), a master regulator of mitochondrial biogenesis ([Link](https://doi.org/10.1006/geno.1999.5977)), further corroborates that this cell is uniquely equipped for massive ATP production. This high metabolic state is likely required to power its primary transport functions. * **Ion and Solute Transport:** A suite of genes directly involved in ion transport are highly specific to this cell. [`ATP6V0C`](/details-gene/527), a component of the V-type H+-ATPase, and [`ATP1B1`](/details-gene/481), a subunit of the Na+/K+ ATPase, are crucial for establishing and maintaining electrochemical gradients across the cell membrane ([Link](https://doi.org/10.1073/pnas.88.10.4289)). The specificity of the potassium channel [`KCNMA1`](/details-gene/3778) also highlights this core function. The transcription factor [`FOXI1`](/details-gene/2299), a known determinant of ionocyte cell fate, is also a highly specific marker ([Link](https://doi.org/10.1074/jbc.272.21.13725)). * **Epithelial Identity and Barrier Function:** The [pulmonary ionocyte](/details-cell/CL0017000) expresses a strong signature of epithelial identity. This includes high specificity for the cytokeratin [`KRT8`](/details-gene/3856), the epithelial cell adhesion molecule [`EPCAM`](/details-gene/4072), and multiple claudins ([`CLDN7`](/details-gene/1366), [`CLDN4`](/details-gene/1364), [`CLDN3`](/details-gene/1365)). These proteins are essential for forming tight junctions and maintaining the integrity of the lung epithelial barrier. * **Signaling and Regulation:** The data suggests potential roles in local signaling. The high specificity of [`GNAS`](/details-gene/2778), which encodes the alpha-subunit of the Gs G-protein, indicates a strong capacity to respond to and transduce extracellular signals via cAMP pathways ([Link](https://doi.org/10.1038/414865a)). Furthermore, the macrophage migration inhibitory factor [`MIF`](/details-gene/4282), a pro-inflammatory cytokine, is also a specific marker, hinting at a potential immunomodulatory role for this cell type within the airway. The **Anti Markers** profile reinforces the cell's specialized nature. The lack of significance for ubiquitously expressed genes involved in general transcription ([`YBX1`](/details-gene/4904)), RNA processing ([`HNRNPC`](/details-gene/3183)), and protein ubiquitination ([`UBE2D3`](/details-gene/7323)) suggests the [pulmonary ionocyte](/details-cell/CL0017000) is a quiescent, terminally differentiated cell with its resources dedicated to function rather than proliferation or general housekeeping. ## Clinical Significance and Contextual Roles The [pulmonary ionocyte's](/details-cell/CL0017000) primary clinical relevance lies in its connection to cystic fibrosis, as it is a principal site of CFTR expression. The dysfunction of ion transport in these cells is central to the disease's pathophysiology. The gene signature provides further insight into potential clinical connections. * The high specificity of genes involved in energy metabolism suggests that diseases affecting mitochondrial function could disproportionately impact [pulmonary ionocyte](/details-cell/CL0017000) viability and function, potentially contributing to respiratory pathologies characterized by impaired airway surface liquid regulation. * The expression of [`ATP6V0C`](/details-gene/527), a gene linked to polycystic kidney disease when mutated ([Link](https://doi.org/10.1073/pnas.88.10.4289)), highlights a shared reliance on V-type ATPases in distinct epithelial tissues for maintaining fluid and ion balance. This suggests potential systemic effects or shared pathogenic mechanisms in ciliopathies or transport-related disorders. * The unique expression of the pro-inflammatory cytokine [`MIF`](/details-gene/4282) suggests that [pulmonary ionocytes](/details-cell/CL0017000) may act as sentinels or modulators of airway inflammation. In chronic inflammatory lung diseases such as asthma or COPD, these cells could contribute to the local cytokine milieu, representing a potential, non-immune therapeutic target. * The presence of [`EPCAM`](/details-gene/4072) is notable, as it is a well-known marker for isolating epithelial cells and is frequently overexpressed in carcinomas. Its high specificity here confirms its role as a key epithelial marker in a healthy context. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The extreme metabolic specialization of the [pulmonary ionocyte](/details-cell/CL0017000), underscored by the unparalleled specificity of mitochondrial electron transport chain genes like [`CYTB`](/details-gene/4519) and [`COX5B`](/details-gene/1329), is the primary determinant of its function. This metabolic phenotype, governed by transcription factors like [`PPARGC1A`](/details-gene/10891), is essential to meet the massive ATP demand required to power the V-type ATPases ([`ATP6V0C`](/details-gene/527)) and other transporters responsible for airway surface liquid homeostasis. * **Surprising Findings:** It is remarkable that the most unique genetic markers of this cell are not the ion transporters themselves (such as CFTR), but rather the mitochondrial "engine" that powers them. This suggests that what truly distinguishes the ionocyte from its epithelial neighbors is its sheer capacity for energy production. * **Testable Questions:** Does genetic or pharmacologic inhibition of [`PPARGC1A`](/details-gene/10891) in lung organoid models lead to a concomitant downregulation of both mitochondrial genes and ion transport function, thereby phenocopying ionocyte dysfunction? 2. **Hypothesis:** The transcription factor [`FOXI1`](/details-gene/2299) functions as the master regulator that orchestrates the complete ionocyte differentiation program. Its activity not only initiates the expression of key functional transporters but also coordinates the upregulation of the specialized cellular machinery required to support this function, including the mitochondrial bioenergetic program and the expression of structural proteins like [`CLDNs`](/details-gene/1364) needed for epithelial integration. * **Surprising Findings:** The co-expression of immunomodulatory molecules like [`MIF`](/details-gene/4282) and key signaling components like [`GNAS`](/details-gene/2778) with such high specificity is unexpected for a cell defined by transport. This implies that the [`FOXI1`](/details-gene/2299)-driven differentiation program may integrate fluid balance with local immune surveillance and signaling functions. * **Testable Questions:** Using single-cell multi-omics (e.g., CITE-seq or ATAC-seq), does the expression of [`FOXI1`](/details-gene/2299) precede and correlate with increased chromatin accessibility at the promoter regions of key mitochondrial, transport, and signaling genes identified in this analysis (e.g., [`CYTB`](/details-gene/4519), [`ATP6V0C`](/details-gene/527), [`MIF`](/details-gene/4282)) during lung development or repair?