Details for: CL0000864

Cell ID: CL0000864

Cell Name: tissue-resident macrophage

Description: A macrophage constitutively resident in a particular tissue under non-inflammatory conditions, and capable of phagocytosing a variety of extracellular particulate material, including immune complexes, microorganisms, and dead cells.

Synonyms: fixed macrophage, resting histiocyte

Selected Context(s): Overall

Gene Significance Landscape

Display Options
Score:
Display
Genes

Contexts:

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 tissue-resident macrophage 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 tissue-resident macrophage. 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 tissue-resident macrophage. 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 tissue-resident macrophage. 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:  tissue-resident macrophage (CL0000864)

 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.

Loading network (please wait)...

## Summary The [tissue-resident macrophage](/details-cell/CL0000864) is a professional phagocyte crucial for tissue homeostasis, immune surveillance, and removal of cellular debris. Based on its gene significance profile, this cell is characterized by an exceptionally high level of metabolic activity, particularly aerobic respiration, and robust machinery for iron homeostasis. The high specificity scores (**csi_z**) for numerous mitochondrial genes ([COX1](/details-gene/4512), [COX2](/details-gene/4513), [CYTB](/details-gene/4519)) alongside iron-binding proteins ([FTL](/details-gene/2512), [FTH1](/details-gene/2495)) underscore its fundamental roles in energy production and iron recycling. Furthermore, the prominence of genes involved in RNA processing and translational control, such as [TPT1](/details-gene/7178) and [NEAT1](/details-gene/283131), suggests that its stable, tissue-specific phenotype is maintained through complex post-transcriptional regulatory networks. ## Key Characteristics and Function **Overall**, the gene expression landscape of the [tissue-resident macrophage](/details-cell/CL0000864) points to a cell that is highly active in both metabolic and biosynthetic processes, consistent with its function as a sentinel and scavenger. The top marker genes can be grouped into several key functional clusters: * **High Metabolic Activity and Oxidative Phosphorylation:** A defining feature is the strong signature of multiple mitochondrially-encoded genes essential for the electron transport chain. This includes high specificity scores for cytochrome c oxidase subunits ([COX1](/details-gene/4512), [COX2](/details-gene/4513)), cytochrome b ([CYTB](/details-gene/4519)), and NADH dehydrogenase subunits ([ND4](/details-gene/4538), [ND3](/details-gene/4537), [ND2](/details-gene/4536)). This pattern strongly suggests that these cells rely heavily on oxidative phosphorylation for the high energetic demands of phagocytosis, protein synthesis, and tissue maintenance. * **Iron Homeostasis and Storage:** The high significance of both ferritin light chain ([FTL](/details-gene/2512)) and heavy chain ([FTH1](/details-gene/2495)) is a classic hallmark of macrophages. These proteins are critical for sequestering and storing iron, a process central to the macrophage's role in recycling iron from senescent erythrocytes and preventing iron-mediated oxidative damage within the tissue. * **RNA Processing and Translational Control:** Several top markers are involved in post-transcriptional regulation. [TPT1](/details-gene/7178) (Translationally Controlled Tumor Protein) is a highly conserved protein involved in cell growth and protein synthesis. The long non-coding RNA [NEAT1](/details-gene/283131), a core structural component of paraspeckles, points to the importance of these nuclear bodies in regulating gene expression. Additionally, the significance of RNA-binding proteins like [PABPC1](/details-gene/26986) and [HNRNPU](/details-gene/3192) further highlights a sophisticated layer of control over mRNA stability, splicing, and translation. * **Immune Function and Signal Transduction:** The presence of [B2M](/details-gene/567) (Beta-2-microglobulin), a component of MHC class I molecules, confirms the cell's capacity for antigen presentation to cytotoxic T lymphocytes. The transcription factors [JUN](/details-gene/3725) and [FOS](/details-gene/2353), which form the AP-1 complex, are key regulators of cellular responses to stimuli, indicating the cell is poised to react to changes in the microenvironment. The **Anti_Markers** provide additional insight. The negative significance scores for certain mitochondrial genes, such as [COX6A1](/details-gene/1337) and [ATP5F1B](/details-gene/506), despite the overall positive signature for mitochondrial components, may suggest a specific, tailored composition of the respiratory chain complexes in these cells, rather than a simple bulk increase in mitochondrial mass. The low relevance of genes like [FCGR2A](/details-gene/2212) (an Fc gamma receptor) in this **Overall** context might suggest that constitutive antibody-mediated phagocytosis is not a defining feature of their resting state across all tissues. ## Clinical Significance and Contextual Roles The gene profile of [tissue-resident macrophages](/details-cell/CL0000864) provides clues to their involvement in various physiological and pathological processes. Their central role in iron metabolism, indicated by [FTL](/details-gene/2512) and [FTH1](/details-gene/2495), is critical for systemic iron balance, and dysfunction can contribute to diseases of both iron overload and deficiency. Several top marker genes have direct links to human diseases, highlighting the potential clinical relevance of this cell type: * The transcription factor [KLF6](/details-gene/1316) has been identified as a key regulator in hepatic fibrosis ([Link](https://pubmed.ncbi.nlm.nih.gov/9689109/)), a process heavily influenced by liver-resident macrophages (Kupffer cells). This suggests that the regulation of [KLF6](/details-gene/1316) in these cells could be a critical node in the development of liver disease. * [ITM2B](/details-gene/9445) is directly implicated in familial British and Danish dementias, which are neurodegenerative diseases characterized by amyloid deposits ([Link](https://doi.org/10.1038/21637)). The specific expression of this gene in tissue-resident macrophages (such as microglia in the brain) may point to their role in the processing or clearance of amyloidogenic proteins. * The AP-1 components [FOS](/details-gene/2353) and [JUN](/details-gene/3725) are proto-oncogenes that are central to inflammation and cell proliferation. Their regulation within tissue-resident macrophages is likely critical in shaping the tumor microenvironment, where they can adopt either pro- or anti-tumoral functions. Given their high metabolic state and role in clearing debris, dysregulation of [tissue-resident macrophages](/details-cell/CL0000864) is likely a key factor in chronic inflammatory diseases, fibrosis, and neurodegeneration. ## Potential Mechanisms and Research Directions ### Hypothesis 1 The complex pattern of both highly positive and specifically negative significance scores for different subunits of the mitochondrial electron transport chain suggests that [tissue-resident macrophages](/details-cell/CL0000864) do not simply increase mitochondrial mass but rather customize the composition of their respiratory complexes. This fine-tuning could optimize energy production for sustained homeostatic functions, differing from the metabolic profile required for an acute inflammatory response. * **Surprising Findings:** It is unexpected to see a strong positive signature for core mitochondrial components like [COX1](/details-gene/4512) and [ND4](/details-gene/4538) co-existing with negative signatures for other structural subunits like [COX6A1](/details-gene/1337) and [ATP6](/details-gene/4508). This suggests a regulated, stoichiometric remodeling of respiratory supercomplexes rather than a uniform upregulation. * **Testable Questions:** Using proteomics, do the relative ratios of different cytochrome c oxidase and ATP synthase subunits within mitochondrial supercomplexes differ between resting [tissue-resident macrophages](/details-cell/CL0000864) and their in-vitro activated, pro-inflammatory counterparts? ### Hypothesis 2 The high specificity of the long non-coding RNA [NEAT1](/details-gene/283131), a key architectural component of paraspeckles, indicates that post-transcriptional gene regulation within these nuclear bodies is a critical mechanism for establishing and maintaining the identity and long-term tissue residency of these macrophages. Paraspeckles may sequester specific mRNAs or transcription factors to buffer the cell against transient inflammatory signals, thereby preserving its homeostatic phenotype. * **Surprising Findings:** The identification of a structural non-coding RNA as a top defining marker, over many cell surface proteins, highlights the importance of internal nuclear organization in defining this cell's stable state. This points away from surface interactions and towards intrinsic gene regulatory architecture as a key feature. * **Testable Questions:** Does conditional knockout of [NEAT1](/details-gene/283131) in a mouse model of [tissue-resident macrophages](/details-cell/CL0000864) lead to a spontaneous loss of their tissue-specific gene expression signature or an exaggerated response to a sub-threshold inflammatory challenge?