Details for: CL3000001

Cell ID: CL3000001

Cell Name: Hofbauer cell

Description: A tissue-resident macrophage that is part of the placenta. A Hofbauer cell expresses high levels of growth factors and metalloproteinases that support vasculogenesis, angiogenesis, branching morphogenesis and tissue remodeling. A Hofbauer cell has a fetal origin, is found in the villous stroma, chorion, and amnion, and is present throughout pregnancy.

Synonyms: HBC, fetal Hofbauer 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 Hofbauer 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 Hofbauer 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 Hofbauer 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 Hofbauer 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.

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Select a context for the target cell.
Target Cell for CSI:  Hofbauer cell (CL3000001)

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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
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 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 [Hofbauer cell](/details-cell/CL3000001) is a tissue-resident macrophage of fetal origin found within the placenta, critical for processes such as vasculogenesis and tissue remodeling. **Overall**, the gene significance profile highlights this cell as a metabolic powerhouse with a specialized, paramount role in iron homeostasis. The top markers, as defined by expression specificity (CSI Z-Score), are dominated by genes involved in iron storage, such as [FTL](/details-gene/2512) and [FTH1](/details-gene/2495), and core metabolic pathways, including multiple components of the mitochondrial electron transport chain ([COX1](/details-gene/4512), [COX2](/details-gene/4513), [ND1](/details-gene/4535), [ND2](/details-gene/4536), [ND3](/details-gene/4537), [ND4](/details-gene/4538)) and glycolysis ([GAPDH](/details-gene/2597)). This signature suggests a primary function centered on managing nutrient and energy flux to support placental and fetal development, coupled with essential immunomodulatory roles. ## Key Characteristics and Function Analysis of the top marker genes reveals several interconnected functional clusters that define the [Hofbauer cell](/details-cell/CL3000001)'s biological identity. * **Iron Metabolism and Storage:** The most significant defining marker is [FTL](/details-gene/2512) (Ferritin Light Chain, CSI: 59.28), with [FTH1](/details-gene/2495) (Ferritin Heavy Chain, CSI: 45.29) also ranking highly. This strong signature for the ferritin complex underscores the cell's critical role as an iron depot within the placental villi, sequestering and managing iron delivery to the developing fetus. This function is fundamental for fetal hematopoiesis and enzymatic processes. * **High Metabolic Activity:** A large proportion of the top markers are involved in cellular energy production. This includes the glycolytic enzyme [GAPDH](/details-gene/2597) and numerous mitochondrially-encoded genes essential for oxidative phosphorylation, such as Cytochrome c oxidase subunits ([COX1](/details-gene/4512), [COX2](/details-gene/4513)) and NADH dehydrogenase subunits ([ND1](/details-gene/4535), [ND2](/details-gene/4536), [ND3](/details-gene/4537), [ND4](/details-gene/4538)). This metabolic profile is consistent with a cell that has high energy demands to sustain its functions of secreting growth factors, remodeling tissue, and supporting angiogenesis throughout gestation. * **Protein Synthesis and Processing:** High expression specificity of genes like [TPT1](/details-gene/7178) (Translationally Controlled Tumor Protein), heterogeneous nuclear ribonucleoproteins ([HNRNPA2B1](/details-gene/3181), [HNRNPC](/details-gene/3183)), and ubiquitin-related genes ([UBC](/details-gene/7316), [UBE2D3](/details-gene/7323)) suggests robust activity in protein synthesis, RNA processing, and protein turnover. This is consistent with its described role in producing and secreting a wide array of signaling molecules and enzymes. * **Immunomodulation:** The presence of [B2M](/details-gene/567) (Beta-2-microglobulin) and the non-classical MHC class I molecule [HLA E](/details-gene/3133) as significant markers points to a role in immune interactions at the maternal-fetal interface. [HLA E](/details-gene/3133) is particularly known for its role in inhibiting the cytotoxic activity of NK cells, suggesting Hofbauer cells contribute to the maintenance of immune tolerance during pregnancy. * **Distinct Lineage Profile:** The anti-marker profile helps to refine the cell's identity. The low significance of scavenger receptors like [SCARF1](/details-gene/8578) and [CD209](/details-gene/30835) (DC-SIGN) suggests that [Hofbauer cells](/details-cell/CL3000001) may utilize alternative, more specialized pathways for antigen uptake compared to other professional phagocytes. Similarly, the low CSI for the eosinophil marker [PRG2](/details-gene/5553) confirms its distinct myeloid lineage. ## Clinical Significance and Contextual Roles Given the singular **Overall** context, the clinical significance of Hofbauer cells can be inferred from the crucial functions highlighted by their top genes. Dysfunction in iron handling, underscored by the prominence of [FTL](/details-gene/2512) and [FTH1](/details-gene/2495), could have severe implications for fetal development, potentially contributing to intrauterine growth restriction or fetal anemia. The cell's intense metabolic signature suggests that it is highly vulnerable to insults that disrupt energy production, such as hypoxia or nutrient deprivation, which are common features of placental insufficiency syndromes. The high CSI for [ITM2B](/details-gene/9445) is notable. While mutations in this gene are associated with familial British and Danish dementias through the formation of amyloid peptides ([Link](https://doi.org/10.1038/21637), [Link](https://doi.org/10.1073/pnas.080076097)), its specific function in Hofbauer cells is unknown. Its strong expression specificity suggests a potentially important, yet uncharacterized, role in placental biology that warrants further investigation. Furthermore, the cell's immunomodulatory profile, marked by [HLA E](/details-gene/3133), positions it as a key player in preventing maternal immune rejection of the semi-allogeneic fetus. Alterations in [HLA E](/details-gene/3133) expression or function on Hofbauer cells could potentially disrupt this delicate balance, contributing to inflammatory complications of pregnancy such as pre-eclampsia or preterm labor. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** Hofbauer cells function as the primary placental regulators of iron bioavailability for the fetus, with their ferritin complex acting as a dynamic buffer to protect against both iron deficiency and toxicity. * **Surprising Findings:** The expression specificity of iron-storage genes ([FTL](/details-gene/2512), [FTH1](/details-gene/2495)) surpasses that of many classical macrophage immune function markers, suggesting that iron management is a primary, rather than ancillary, function of this cell type. * **Testable Questions:** Using an *in vitro* co-culture system of Hofbauer cells and fetal endothelial cells, does siRNA-mediated knockdown of [FTL](/details-gene/2512) in Hofbauer cells alter the rate and efficiency of iron transfer to the endothelial cells under varying iron conditions? 2. **Hypothesis:** The high and specific expression of the non-classical MHC molecule [HLA E](/details-gene/3133), combined with a lack of significance for canonical scavenger receptors, indicates that Hofbauer cells primarily function to induce immune tolerance via direct interaction with uterine NK cells, rather than to perform broad pathogen surveillance. * **Surprising Findings:** The gene signature points towards a highly specialized immunomodulatory role focused on tolerance, which contrasts with the more versatile immune-surveillance and pro-inflammatory potential of other tissue-resident macrophages. * **Testable Questions:** Does the co-culture of primary human Hofbauer cells with activated uterine NK cells result in suppression of NK cell degranulation and cytokine production, and can this suppression be reversed using a blocking antibody against [HLA E](/details-gene/3133)?