Details for: CL0000155

Cell ID: CL0000155

Cell Name: peptic cell

Description: An epithelial cell of the stomach that is part of the fundic gastric gland. This cell is characterized by a basally located nucleus, abundant rough endoplasmic reticulum, and large apical secretory granules. It produces and secretes pepsinogen, the inactive precursor of the digestive enzyme pepsin.

Synonyms: chief cell of stomach, pepsinogen secreting cell, gastric chief cell, zymogenic cell

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 peptic cell 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 peptic cell. 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 peptic cell. 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 peptic cell. 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:  peptic cell (CL0000155)

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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 The [peptic cell](/details-cell/CL0000155), also known as the gastric chief cell, is a specialized epithelial cell of the stomach fundic gland responsible for secreting pepsinogen. Based on gene significance analysis, its identity is defined by an exceptionally high metabolic rate, underpinned by the specific expression of numerous nuclear and mitochondrial-encoded components of the respiratory chain. Furthermore, top markers for protein synthesis, quality control, and iron homeostasis machinery, such as ubiquitin ([UBB](/details-gene/7314)) and ferritin ([FTH1](/details-gene/2495), [FTL](/details-gene/2512)), highlight its role as a professional secretory cell with robust systems to support high-volume protein production and manage the associated metabolic demands. ## Key Characteristics and Function The gene expression profile of the [peptic cell](/details-cell/CL0000155) provides strong evidence for its primary role as a high-output protein factory specialized for enzyme secretion. This function is supported by several interconnected biological themes identified from its top specific markers in the **Overall** context. * **Intense Mitochondrial Energy Production:** A striking feature of this cell is the highly specific expression of a large suite of genes involved in aerobic respiration. This includes numerous mitochondrially-encoded genes such as [ND2](/details-gene/4536), [ND3](/details-gene/4537), [ND4](/details-gene/4538), [COX1](/details-gene/4512), [COX2](/details-gene/4513), [ATP6](/details-gene/4508), and [CYTB](/details-gene/4519), as well as nuclear-encoded components like [COX4I1](/details-gene/1327) and [NDUFA4](/details-gene/4697). The high `csi_z` scores for these genes indicate that this intense level of mitochondrial activity is a defining characteristic that distinguishes peptic cells from other cell types, providing the necessary ATP to fuel the synthesis and exocytosis of pepsinogen. * **Robust Protein Synthesis and Quality Control:** Consistent with its secretory function, the [peptic cell](/details-cell/CL0000155) shows specific expression of genes essential for protein management. The ubiquitin genes [UBB](/details-gene/7314) and [UBC](/details-gene/7316) are top markers, suggesting a critical role for the ubiquitin-proteasome system in maintaining protein homeostasis and degrading misfolded proteins, a common challenge in cells with high secretory loads. The high significance of the translational elongation factor [EEF1D](/details-gene/1936) further underscores the cell's commitment to efficient protein synthesis. * **Specialized Iron Homeostasis:** The ferritin heavy and light chain genes, [FTH1](/details-gene/2495) and [FTL](/details-gene/2512), are among the most specific markers. This suggests a crucial requirement for managing iron, a key cofactor for the heme groups in the mitochondrial electron transport chain. A robust iron storage system would be necessary to meet the high metabolic demand while simultaneously mitigating the potential for iron-induced oxidative stress. * **RNA Processing and Regulation:** The specific expression of RNA-binding proteins like [CIRBP](/details-gene/1153) and [YBX1](/details-gene/4904) points towards the importance of post-transcriptional regulation in controlling the fate of mRNAs, likely including the highly abundant pepsinogen transcripts. * **Defining by Absence (Anti-Markers):** The cell's identity is also clarified by genes it does not specifically express. The low significance of genes associated with other lineages, such as the myeloid-associated GTPase [RAB3D](/details-gene/9545) or the neural cell adhesion molecule [NCAM1](/details-gene/4684), confirms its distinct epithelial identity. Notably, the aquaporin [AQP4](/details-gene/361) has a very low CSI, which is consistent with literature suggesting its expression is higher in the acid-secreting parietal cells of the stomach ([Link](https://doi.org/10.1016/0014-5793(96)00092-0)). ## Clinical Significance and Contextual Roles The analysis is based on an **Overall** context, which limits direct comparison between healthy and diseased states. However, the revealed genetic architecture of the [peptic cell](/details-cell/CL0000155) points to several areas of clinical relevance. The profound dependence on mitochondrial function suggests this cell type may be particularly vulnerable to mitochondrial toxins, metabolic diseases, or systemic conditions that induce mitochondrial stress. Mutations in mitochondrial genes like [CYTB](/details-gene/4519) are known to cause severe pathologies such as cardiomyopathy ([Link](https://doi.org/10.1007/bf00711378)), indicating that impairments in these core metabolic pathways can have profound cellular consequences. Dysfunction in peptic cells could lead to impaired protein digestion and potentially contribute to gastric pathologies. Furthermore, the high significance of the ubiquitin system ([UBB](/details-gene/7314), [UBC](/details-gene/7316)) highlights the importance of protein quality control. Dysregulation of this system is a hallmark of many diseases, including cancer and neurodegeneration. In the stomach, failure of this system could lead to the accumulation of unfolded proteins, triggering cellular stress responses that might contribute to gastritis or other inflammatory conditions. The tight regulation of iron metabolism, indicated by [FTH1](/details-gene/2495) and [FTL](/details-gene/2512), is also critical, as iron overload can catalyze the formation of reactive oxygen species, leading to cellular damage and inflammation. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The specific, high-level expression of ferritin subunits ([FTH1](/details-gene/2495) and [FTL](/details-gene/2512)) suggests that a specialized iron buffering system is a core, defining feature of [peptic cells](/details-cell/CL0000155), essential for supplying iron to their extensive mitochondrial machinery while preventing iron-catalyzed oxidative damage. * **Surprising Findings:** While high expression of mitochondrial genes is expected in a secretory cell, the equally high specificity of iron *storage* proteins is notable. This suggests that the management of iron supply and toxicity is as integral to the peptic cell's unique identity as the process of energy production itself. * **Testable Questions:** Does selective knockdown of [FTH1](/details-gene/2495) in a gastric organoid model lead to a disproportionate increase in oxidative stress and a specific decrease in pepsinogen secretion in peptic cells, even under normal iron conditions? 2. **Hypothesis:** The balanced co-expression of both nuclear-([COX4I1](/details-gene/1327)) and mitochondrial-([COX1](/details-gene/4512), [COX2](/details-gene/4513)) encoded subunits of the cytochrome c oxidase complex indicates that the maintenance of mitochondrial genome integrity and its coordinated transcription with the nuclear genome represents a key functional axis and a potential vulnerability for [peptic cells](/details-cell/CL0000155). * **Surprising Findings:** The significance profile is not dominated by either nuclear or mitochondrial genes alone, but rather shows an integrated signature of both. This underscores an exceptionally tight stoichiometric requirement and regulatory coupling between the two genomes to meet the cell's extreme energetic demands. * **Testable Questions:** Do agents that specifically induce mitochondrial DNA damage (e.g., certain nucleoside analogs or chronic oxidative stress) lead to a more rapid decline in the functional capacity (i.e., pepsinogen release) and viability of [peptic cells](/details-cell/CL0000155) compared to adjacent gastric cell types, such as parietal or mucous neck cells?