Details for: CL0002275

Cell ID: CL0002275

Cell Name: pancreatic PP cell

Description: The term PP cell of pancreatic acinus was obsoleted due to a lack of evidence, making PP cell of pancreatic islets synonymous with pancreatic PP cell.

Synonyms: PP cell of pancreatic islet, PP-cell of pancreatic islet, pancreatic polypeptide-secreting cell

Selected Context(s): Overall

Gene Significance Landscape

Display Options
Score:
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Genes

Contexts:

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

Image representation

Depiction of pancreatic PP cell
Courtesy of SwissBioPics

Significant Genes List

Genes with the highest and lowest Percentile Rank Scores (PRS) for pancreatic PP 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 pancreatic PP 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 pancreatic PP 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 pancreatic PP 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:  pancreatic PP cell (CL0002275)

 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.

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## Summary The [pancreatic PP cell](/details-cell/CL0002275) is a neuroendocrine cell type located within the islets of Langerhans, primarily known for its synthesis and secretion of pancreatic polypeptide. The gene significance profile, based on expression specificity (**Overall** context), suggests that this cell is not only a specialized hormone-producing unit but also a powerhouse of fundamental cellular processes. The most defining markers are not the namesake hormone itself but rather genes involved in high-throughput protein synthesis and processing (e.g., [SRP14](/details-gene/6727)), energy metabolism (e.g., [ATP6](/details-gene/4508), [COX2](/details-gene/4513)), and cellular homeostasis, particularly iron management ([FTH1](/details-gene/2495), [FTL](/details-gene/2512)). This indicates that the unique identity of the [pancreatic PP cell](/details-cell/CL0002275) is characterized by an exceptionally high and specific level of core metabolic and protein-handling activity. ## Key Characteristics and Function Analysis of the top markers by Z-score reveals several key functional clusters that define the [pancreatic PP cell](/details-cell/CL0002275). * **High-Capacity Protein Synthesis and Processing:** A significant number of top markers are involved in protein production and RNA management. [SRP14](/details-gene/6727), a component of the signal recognition particle, is the most specific marker (CSI-Z: 26.23), highlighting the cell's intense focus on translocating newly synthesized proteins. This is complemented by the high specificity of genes involved in RNA binding and splicing like [PNISR](/details-gene/25957) and [HNRNPA2B1](/details-gene/3181). The high specificity of ubiquitin-related genes [SKP1](/details-gene/6500) and [UBC](/details-gene/7316) suggests a correspondingly high rate of protein turnover and quality control. * **Robust Energy Metabolism:** The cell exhibits a strong reliance on aerobic respiration, evidenced by the high specificity of multiple mitochondrial genes. These include components of the ATP synthase complex ([ATP6](/details-gene/4508), [ATP5MC2](/details-gene/517)) and the electron transport chain ([COX2](/details-gene/4513), [ND4](/details-gene/4538), [COX7A2](/details-gene/1347)). The high specificity of the glycolytic enzyme [GAPDH](/details-gene/2597) further underscores the cell's high energetic demand, likely required to fuel continuous hormone synthesis and secretion. * **Specialized Cellular Homeostasis and Secretion:** The [pancreatic PP cell](/details-cell/CL0002275) displays a defining signature in managing metal ions and oxidative stress. The ferritin heavy and light chains, [FTH1](/details-gene/2495) and [FTL](/details-gene/2512), are among the most specific markers, suggesting a specialized role in iron sequestration. Concurrently, [SOD1](/details-gene/6647), a key enzyme in mitigating superoxide radicals, is also highly specific, indicating a robust system for managing oxidative stress. The presence of [SCG3](/details-gene/29106) (Secretogranin III) is consistent with its neuroendocrine identity and role in the regulated secretory pathway of peptide hormones. Furthermore, the high specificity of calmodulin genes ([CALM1](/details-gene/801), [CALM2](/details-gene/805)) points towards the importance of calcium signaling in orchestrating these secretory events. * **Anti-Markers Define Lineage Boundaries:** The lack of specificity for several genes helps to distinguish PP cells from other islet and neuronal cell types. For example, [SLC30A8](/details-gene/169026), a zinc transporter critical for insulin crystallization in beta cells, is a strong anti-marker, confirming the distinct identity of PP cells. Similarly, the low specificity for [NPY](/details-gene/4852) (Neuropeptide Y) is notable; while often co-expressed with pancreatic polypeptide, its expression is likely more widespread across other cell types, reducing its utility as a unique identifier for this specific cell in this analysis. ## Clinical Significance and Contextual Roles Given that the analysis is based on an **Overall** context, the clinical insights are derived from the inherent functions of the top marker genes rather than from a comparison across different health states. The high specificity of ferritin genes ([FTH1](/details-gene/2495), [FTL](/details-gene/2512)) suggests that [pancreatic PP cells](/details-cell/CL0002275) may play a significant role in pancreatic iron homeostasis. Dysregulation of iron metabolism is implicated in pancreatic damage and the pathogenesis of diabetes. Therefore, these cells could be particularly vulnerable to, or key players in, iron overload-induced pancreatic dysfunction. Furthermore, the high specificity of [SOD1](/details-gene/6647) is clinically relevant. While mutations in [SOD1](/details-gene/6647) are famously linked to amyotrophic lateral sclerosis (ALS), its prominent role in PP cells suggests these cells are well-equipped to handle high levels of oxidative stress, a common feature of the metabolically active islet microenvironment. This intrinsic protective mechanism could be a critical factor in islet survival under metabolic stress. The neuroendocrine marker [SCG3](/details-gene/29106) may be relevant in the context of pancreatic neuroendocrine tumors (PanNETs). As a key component of secretory granules, its expression patterns could serve as a diagnostic marker or a potential therapeutic target in tumors originating from the PP cell lineage. The high specificity of general metabolic and protein synthesis machinery ([SRP14](/details-gene/6727), [GAPDH](/details-gene/2597)) also suggests that therapeutic strategies targeting these fundamental pathways might have a pronounced effect on PP cell-derived pathologies. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The defining characteristic of a [pancreatic PP cell](/details-cell/CL0002275) is not simply the production of pancreatic polypeptide, but its function as a metabolic sentinel with an exceptionally high basal rate of protein turnover and energy production that surpasses other islet cells. This high metabolic state may be crucial for supporting the entire islet microenvironment. * **Surprising Findings:** The canonical marker for this cell, Pancreatic Polypeptide (PPY), is not among the top genes with the highest expression *specificity*. Instead, fundamental "housekeeping" genes like [SRP14](/details-gene/6727), [FTH1](/details-gene/2495), and multiple mitochondrial components define its unique transcriptional identity. This suggests that the *rate and nature* of its core cellular processes are more distinctive than the single hormone it produces. * **Testable Questions:** Does selective ablation of [pancreatic PP cells](/details-cell/CL0002275) in an in-vivo model lead to measurable metabolic deficits or increased stress in adjacent alpha and beta cells, particularly under conditions of high metabolic demand? 2. **Hypothesis:** [Pancreatic PP cells](/details-cell/CL0002275) serve as specialized regulators of iron metabolism and oxidative stress within the pancreatic islet, sequestering excess iron via high ferritin expression and neutralizing resultant reactive oxygen species through elevated [SOD1](/details-gene/6647) activity. * **Surprising Findings:** While all islet cells face oxidative stress, the data pinpoints iron management specifically ([FTH1](/details-gene/2495), [FTL](/details-gene/2512)) as a uniquely defining feature of PP cells. This suggests a division of labor within the islet where PP cells may buffer the local microenvironment from iron-induced toxicity. * **Testable Questions:** Using lineage tracing and imaging techniques, can we demonstrate preferential iron uptake and storage within [pancreatic PP cells](/details-cell/CL0002275) compared to beta cells in response to systemic iron loading? Does this sequestration protect neighboring cells from ferroptosis?