Details for: CL1000488

Cell ID: CL1000488

Cell Name: cholangiocyte

Description: An epithelial cell that is part of the bile duct. Cholangiocytes contribute to bile secretion via net release of bicarbonate and water. They are cuboidal epithelium in the small interlobular bile ducts, but become columnar and mucus secreting in larger bile ducts approaching the porta hepatis and the extrahepatic ducts.

Synonyms: epithelial cell of bile duct

Selected Context(s): Overall

Gene Significance Landscape

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Genes

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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 cholangiocyte 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 cholangiocyte. 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 cholangiocyte. 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 cholangiocyte. 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:  cholangiocyte (CL1000488)

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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.

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## Summary A [cholangiocyte](/details-cell/CL1000488) is a specialized epithelial cell forming the lining of the bile ducts. Its primary described function is to modify bile composition through secretory and absorptive processes. The gene significance profile suggests that beyond its secretory role, the cholangiocyte identity is uniquely defined by an extensive and highly specific machinery for post-transcriptional gene regulation. The top marker, the long non-coding RNA [NEAT1](/details-gene/283131), combined with numerous highly significant RNA-binding and splicing factors, points to a sophisticated control of gene expression from within the nucleus, likely essential for maintaining its barrier integrity and complex metabolic functions. ## Key Characteristics and Function The gene expression profile of the [cholangiocyte](/details-cell/CL1000488) reveals a cell with a multifaceted role centered around high metabolic activity, structural maintenance, and intricate regulation of gene expression. The top marker genes can be categorized into several key functional clusters. - **RNA Processing and Nuclear Organization:** A predominant feature of the cholangiocyte signature is the high specificity of genes involved in RNA metabolism. This includes the top marker [NEAT1](/details-gene/283131), a key structural component of nuclear paraspeckles, and a suite of RNA-binding proteins and splicing factors such as [HNRNPC](/details-gene/3183), [SRSF11](/details-gene/9295), [RBM39](/details-gene/9584), [SRRM2](/details-gene/23524), and [DDX17](/details-gene/10521). This collective signature strongly suggests that post-transcriptional regulation, including alternative splicing and mRNA export, is a defining and crucial aspect of cholangiocyte biology, allowing for precise control over its functional proteome. - **Metabolism and Detoxification:** Consistent with its role in the biliary system, the [cholangiocyte](/details-cell/CL1000488) expresses specific genes for metabolic processes. [CYP3A5](/details-gene/1577), a cytochrome P450 enzyme, points to a role in xenobiotic and lipid metabolism. The high significance of [FTL](/details-gene/2512) (Ferritin Light Chain) indicates a key function in iron storage and homeostasis, protecting the cell from iron-induced oxidative stress. Additionally, the presence of [PPARGC1A](/details-gene/10891), a master regulator of mitochondrial biogenesis and energy metabolism, and [ATP5MC3](/details-gene/518), a component of ATP synthase, underscores the cell's high energy demands. - **Structural Integrity and Transport:** As an epithelial cell forming a critical barrier, structural integrity is paramount. The high significance of [SPTBN1](/details-gene/6711) (Spectrin Beta, Non-Erythrocytic 1), an actin-binding protein, highlights the importance of the cytoskeleton in maintaining cell shape and ductal structure. [ANXA2](/details-gene/302), involved in membrane organization and repair, further supports this role. The cell also expresses genes for major transport proteins like [ALB](/details-gene/213) (Albumin) and [TF](/details-gene/7018) (Transferrin), suggesting it may contribute to the transport and secretion of these key plasma proteins. - **Transcriptional Control:** The epithelium-specific transcription factor [ELF3](/details-gene/1999) shows a high specificity score, indicating its importance in establishing and maintaining the cholangiocyte's epithelial lineage and differentiated state. **Overall**, the anti-marker profile reveals a relative lack of specificity for common stress-inducible transcription factors like [JUN](/details-gene/3725), [JUNB](/details-gene/3726), and [JUND](/details-gene/3727), as well as ubiquitously expressed metabolic enzymes like [GAPDH](/details-gene/2597). This suggests that under baseline conditions, the cell's identity is defined more by its specialized regulatory and structural machinery than by generic stress or metabolic pathways. ## Clinical Significance and Contextual Roles The gene signature of [cholangiocytes](/details-cell/CL1000488) provides insights into their potential roles in liver health and disease. The prominent role of RNA processing machinery suggests that dysregulation of splicing could be a key mechanism in biliary diseases. Aberrant splicing events are known drivers of various cancers, and the high specificity of factors like [SRRM2](/details-gene/23524) and [HNRNPC](/details-gene/3183) could make them potential therapeutic targets or biomarkers in cholangiocarcinoma. The cell's metabolic profile is also clinically significant. The expression of [CYP3A5](/details-gene/1577) is relevant for understanding drug metabolism and drug-induced liver injury, as cholangiocytes are directly exposed to xenobiotics excreted in bile. The specific expression of iron-handling proteins like [FTL](/details-gene/2512) positions the [cholangiocyte](/details-cell/CL1000488) as a potential player in the pathophysiology of iron-overload diseases that affect the liver. Furthermore, genes like [ANXA2](/details-gene/302), associated with angiogenesis and membrane dynamics, may be involved in the tissue repair and fibrotic responses seen in chronic cholestatic diseases such as primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC). The high expression of transport proteins like [ALB](/details-gene/213) and [TF](/details-gene/7018), typically associated with hepatocytes, suggests that cholangiocyte dysfunction could have a broader impact on systemic protein homeostasis than previously understood. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The identity and specialized function of [cholangiocytes](/details-cell/CL1000488) are critically dependent on a sophisticated network of post-transcriptional regulation, orchestrated by nuclear architectural lncRNAs and a specific cohort of splicing factors. This network may fine-tune the proteome required for maintaining the bile duct barrier and responding to biliary stress, with its dysregulation being an initiating event in cholangiopathies. - **Surprising Findings:** The most specific marker for this secretory epithelial cell is not a transporter or a secreted protein but [NEAT1](/details-gene/283131), a nuclear non-coding RNA. This finding elevates the importance of nuclear organization and RNA processing from a housekeeping function to a defining feature of cholangiocyte identity. - **Testable Questions:** Does inactivation of [NEAT1](/details-gene/283131) or key splicing factors like [RBM39](/details-gene/9584) in cholangiocyte-specific mouse models alter the expression of ion transporters, compromise epithelial barrier function, and increase susceptibility to chemically induced cholestatic injury? 2. **Hypothesis:** [Cholangiocytes](/details-cell/CL1000488) act as more than just passive conduits; they are active metabolic regulators within the liver microenvironment, contributing significantly to systemic xenobiotic, iron, and protein homeostasis. This function is mediated by a specific suite of enzymes and transporters, including [CYP3A5](/details-gene/1577), [FTL](/details-gene/2512), and potentially even [ALB](/details-gene/213). - **Surprising Findings:** The high specificity score for [ALB](/details-gene/213) (albumin), the canonical marker for hepatocytes, is unexpected. This suggests that [cholangiocytes](/details-cell/CL1000488) may either synthesize albumin under certain conditions or play a key role in its transport into bile, challenging the traditional view of a strict functional separation between hepatocytes and cholangiocytes. - **Testable Questions:** What is the functional consequence of [CYP3A5](/details-gene/1577) expression in [cholangiocytes](/details-cell/CL1000488)? Do these cells actively metabolize drugs and toxins, and does this activity contribute to the pathology of drug-induced biliary injury? Furthermore, can protein expression and secretion of [ALB](/details-gene/213) from isolated cholangiocyte organoids be confirmed *in vitro*?