Details for: CL0009006

Cell ID: CL0009006

Cell Name: enteroendocrine cell of small intestine

Description: An enteroendocrine cell that is located in the small intestine.

Synonyms: small intestine enteroendocrine cell

Selected Context(s): Overall

Gene Significance Landscape

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

Image representation

Depiction of enteroendocrine cell of small intestine
Courtesy of SwissBioPics

Significant Genes List

Genes with the highest and lowest Percentile Rank Scores (PRS) for enteroendocrine cell of small intestine 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 enteroendocrine cell of small intestine. 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 enteroendocrine cell of small intestine. 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 enteroendocrine cell of small intestine. 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.

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Target Cell for CSI:  enteroendocrine cell of small intestine (CL0009006)

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Nodes (Genes):
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Node size also reflects Target Cell CSI magnitude.
Node Color (Target Cell CSI in specific network):
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 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 The [enteroendocrine cell of small intestine](/details-cell/CL0009006) is a specialized secretory cell type located within the epithelial lining of the small intestine. Gene significance analysis reveals that its identity is overwhelmingly defined by an exceptionally high and specific expression of genes involved in mitochondrial aerobic respiration. The **Overall** transcriptional signature is dominated by components of the electron transport chain, such as [COX1](/details-gene/4512), [ND4](/details-gene/4538), and [CYTB](/details-gene/4519). This profile strongly suggests that the cell's primary functional state is that of a metabolic powerhouse, geared towards generating large amounts of ATP to fuel its principal role in synthesizing and secreting hormones that regulate digestion, metabolism, and homeostasis. ## Key Characteristics and Function Analysis of top marker genes highlights several core functional clusters that define the [enteroendocrine cell of small intestine](/details-cell/CL0009006). * **Mitochondrial Bioenergetics:** The most prominent characteristic of this cell type is its profound reliance on oxidative phosphorylation. Nearly all of the top-ranking genes based on expression specificity (`csi_z`) are components of the mitochondrial genome encoding subunits of the respiratory chain. This includes markers for Complex I ([ND1](/details-gene/4535), [ND2](/details-gene/4536), [ND3](/details-gene/4537), [ND4](/details-gene/4538), [ND5](/details-gene/4540)), Complex III ([CYTB](/details-gene/4519)), Complex IV ([COX1](/details-gene/4512), [COX2](/details-gene/4513)), and Complex V ([ATP6](/details-gene/4508)). This is further supported by the high significance of nuclear-encoded mitochondrial proteins like [COX4I1](/details-gene/1327), [COX6C](/details-gene/1345), and [COX5B](/details-gene/1329). This extensive and highly specific expression profile indicates an extraordinary capacity for ATP synthesis, which is consistent with the high energy demands of peptide hormone production and vesicular transport. * **Calcium-Dependent Signaling and Secretion:** A secondary functional theme is the machinery for calcium signaling, which is critical for stimulus-secretion coupling in endocrine cells. High significance scores for calcium-binding proteins such as [CALM1](/details-gene/801) (Calmodulin 1) and [S100A6](/details-gene/6277) (Calcyclin) suggest a finely-tuned system for regulating exocytosis in response to intracellular calcium fluxes. The expression of these genes, coupled with the cell's vast energy reserves, points to a robust capacity for regulated hormone release. * **Metabolic Support and General Housekeeping:** The cell also expresses high levels of genes that support its high metabolic rate and protein synthesis machinery. This includes [FTL](/details-gene/2512) and [FTH1](/details-gene/2495), the light and heavy chains of ferritin, respectively, which are crucial for storing iron, an essential cofactor for the cytochromes of the electron transport chain. Other significant genes like [B2M](/details-gene/567) and the histone gene [H3-3B](/details-gene/3021) reflect active cellular maintenance and protein turnover. * **Defining by Absence (Anti-Markers):** The low significance of genes associated with neuronal function ([NPAS3](/details-gene/64067), [KCNH6](/details-gene/81033)) or specific developmental transcription factors ([MNX1](/details-gene/3110), [ISL1](/details-gene/3670)) helps to refine the cell's identity. This suggests that in its mature state, the [enteroendocrine cell of small intestine](/details-cell/CL0009006) is a highly specialized, terminally differentiated secretory cell, with its transcriptional identity being primarily driven by metabolic function rather than neuronal excitability or active lineage specification programs. ## Clinical Significance and Contextual Roles **Overall**, the gene signature of the [enteroendocrine cell of small intestine](/details-cell/CL0009006) underscores its central role in metabolic regulation. These cells are the source of crucial hormones like glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK), and secretin, which are fundamental to glucose homeostasis and digestive processes. The profound dependence on mitochondrial function makes this cell type a potential nexus for pathologies involving metabolic dysregulation. Mitochondrial dysfunction could directly impair hormone synthesis and secretion, potentially contributing to the pathophysiology of metabolic disorders such as type 2 diabetes and obesity. One study on colonic adenocarcinoma cells found that increased expression of mitochondrial RNA, including [ND4](/details-gene/4538), correlated with cellular differentiation ([Link](https://pubmed.ncbi.nlm.nih.gov/1377597/)), highlighting the intimate link between mitochondrial activity and the specialized function of intestinal epithelial lineages. The high expression of calcium signaling components like [CALM1](/details-gene/801) and [S100A6](/details-gene/6277) also presents potential therapeutic targets. Modulating the activity of these pathways could offer a strategy for controlling the release of metabolically active hormones from these cells, which is the mechanism of action for several modern diabetes therapies. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The defining functional state of the [enteroendocrine cell of small intestine](/details-cell/CL0009006) is dictated by an exceptionally high, constitutively active aerobic respiration program, which is essential to fuel the continuous synthesis and regulated secretion of peptide hormones. The cell's unique identity among epithelial neighbors appears to be a direct consequence of its extreme metabolic specialization. * **Surprising Findings:** The degree to which mitochondrial-encoded genes dominate the `csi_z` scores is remarkable. It suggests that metabolic capacity is not merely a supporting function but is the most distinguishing transcriptional feature of this cell type compared to other cells in the small intestine epithelium. * **Testable Questions:** Does pharmacological inhibition of specific electron transport chain complexes (e.g., using rotenone for Complex I or antimycin A for Complex III) disproportionately impair hormone secretion from [enteroendocrine cell of small intestine](/details-cell/CL0009006) compared to the absorptive function of neighboring [enterocytes](/details-cell/CL0000057)? 2. **Hypothesis:** The co-expression of a robust calcium signaling toolkit, marked by high levels of [CALM1](/details-gene/801) and [S100A6](/details-gene/6277), is tightly integrated with the cell's mitochondrial output to ensure precise, energy-dependent control over hormone exocytosis in response to luminal nutrient sensing. This system likely acts as a checkpoint, ensuring that large-scale secretion only occurs when sufficient ATP is available. * **Surprising Findings:** While calcium's role in secretion is well-established, the data reveal that specific calcium-binding proteins, such as [S100A6](/details-gene/6277), are among the most significant markers alongside core metabolic genes. This colocalization at the top of the significance list suggests a more deeply integrated regulatory circuit than previously appreciated. * **Testable Questions:** In an enteroendocrine cell line model (e.g., STC-1), how does siRNA-mediated knockdown of [S100A6](/details-gene/6277) alter the kinetics and magnitude of hormone release triggered by a calcium ionophore, and is this effect exacerbated under conditions of metabolic stress like glucose deprivation?