Details for: CL0019019

Cell ID: CL0019019

Cell Name: tracheobronchial smooth muscle cell

Description: A smooth muscle cell that is part of the tracheobronchial tree.

Synonyms: smooth muscle cell of tracheobronchial tree

Selected Context(s): Overall

Gene Significance Landscape

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Score:
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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 tracheobronchial smooth muscle 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 tracheobronchial smooth muscle 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 tracheobronchial smooth muscle 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 tracheobronchial smooth muscle 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:  tracheobronchial smooth muscle cell (CL0019019)

 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 [tracheobronchial smooth muscle cell](/details-cell/CL0019019) is a specialized contractile cell integral to the structure and function of the tracheobronchial tree. **Overall**, its gene significance profile is dominated by components of the muscular contractile apparatus and calcium signaling pathways. The exceptionally high specificity of [MYL6](/details-gene/4637) (CSI: 56.70), a myosin light chain, underscores its primary function in regulating airway tone through bronchoconstriction and bronchodilation. This cell type is characterized by a molecular signature finely tuned for electromechanical coupling and sustained contraction, positioning it as a central player in respiratory physiology and pathology. ## Key Characteristics and Function The functional identity of the [tracheobronchial smooth muscle cell](/details-cell/CL0019019) is defined by several core clusters of highly specific genes. * **Contractile and Cytoskeletal Machinery:** The most defining characteristic of this cell is its robust expression of genes involved in muscle contraction. [MYL6](/details-gene/4637), an alkali myosin light chain, exhibits the highest expression specificity (rCSI: 100.0%), confirming its role as a fundamental component of the smooth muscle motor. This is complemented by other contractile-associated proteins such as [MYL12A](/details-gene/10627) and [CFL1](/details-gene/1072), which regulates actin filament dynamics critical for cellular contraction and relaxation. The presence of structural proteins like [KRT8](/details-gene/3856) and the microtubule-associated protein [MAP1B](/details-gene/4131), both with a maximal effect size of +1.0000, suggests a well-developed cytoskeleton necessary to withstand the mechanical forces of the respiratory cycle. * **Calcium-Dependent Signaling:** Smooth muscle contraction is inextricably linked to calcium signaling, a fact strongly reflected in the cell's marker profile. [S100A6](/details-gene/6277) (Calcyclin), a calcium-binding protein, is the second most specific marker (CSI: 43.77), indicating a crucial role in transducing calcium signals. The significance of other calcium-binding proteins like [TPT1](/details-gene/7178) and [CALM2](/details-gene/805) further highlights a sophisticated system for regulating intracellular calcium concentration and modulating the contractile response. * **Metabolic and Protective Functions:** The cell displays a signature of high metabolic activity to support its contractile function, evidenced by the significance of genes involved in iron homeostasis ([FTH1](/details-gene/2495), [FTL](/details-gene/2512]) and energy metabolism ([GAPDH](/details-gene/2597), [NDUFA4](/details-gene/4697)). The expression of [GSTP1](/details-gene/2950), an enzyme involved in detoxifying reactive oxygen species, suggests a capacity to mitigate oxidative stress from inflammation or environmental insults. Furthermore, the notable expression of [B2M](/details-gene/567) indicates that these cells participate in immune surveillance through MHC class I antigen presentation. * **Negative Signature:** The anti-marker profile provides critical insight into what this cell is not. A strong negative signature for numerous genes involved in RNA splicing and processing (e.g., [HNRNPA2B1](/details-gene/3181), [HNRNPDL](/details-gene/9987), [HNRNPC](/details-gene/3183)) suggests that [tracheobronchial smooth muscle cells](/details-cell/CL0019019) may maintain a relatively stable transcriptome with less reliance on dynamic alternative splicing compared to other cell types. The strong negative enrichment for several core mitochondrial DNA-encoded genes of the respiratory chain (e.g., [COX1](/details-gene/4512), [COX3](/details-gene/4514), [ND4](/details-gene/4538)) is also noteworthy and may point towards specific metabolic specializations. ## Clinical Significance and Contextual Roles The gene profile of the [tracheobronchial smooth muscle cell](/details-cell/CL0019019) directly informs its role in respiratory diseases characterized by airway dysregulation, such as asthma and chronic obstructive pulmonary disease (COPD). The profound significance of the contractile and calcium-signaling machinery ([MYL6](/details-gene/4637), [S100A6](/details-gene/6277)) aligns with the pathophysiology of airway hyperreactivity, where exaggerated contraction of these cells leads to bronchospasm. Consequently, these pathways are the primary targets for bronchodilator therapies. The specific expression of cytoprotective genes like [GSTP1](/details-gene/2950) suggests a role in defending the airways against oxidative damage, a key feature of chronic inflammatory lung diseases. Dysregulation of this protective capacity could contribute to the progressive airway remodeling seen in severe asthma and COPD. Additionally, the identification of [ITM2B](/details-gene/9445), a gene linked to amyloid fiber formation ([Link](https://doi.org/10.1038/21637)), as a marker is intriguing and may suggest a previously unappreciated role for protein aggregation in the context of chronic airway inflammation or remodeling. ## Potential Mechanisms and Research Directions 1. **Hypothesis: Tracheobronchial smooth muscle cells exhibit a specialized metabolic profile favoring glycolysis for rapid contractile responses.** * **Surprising Findings:** The data reveal a strong negative significance for multiple core components of the mitochondrial electron transport chain encoded by mitochondrial DNA (e.g., [COX1](/details-gene/4512), [ATP6](/details-gene/4508), [ND4](/details-gene/4538)), which is counterintuitive for a cell type requiring sustained energy production. This occurs alongside a positive significance for [GAPDH](/details-gene/2597), a key glycolytic enzyme. * **Testable Questions:** In an ex vivo model of tracheal ring contraction, does the inhibition of glycolysis (e.g., using 2-deoxy-D-glucose) more effectively block agonist-induced contraction compared to the inhibition of oxidative phosphorylation (e.g., using oligomycin)? 2. **Hypothesis: Iron-handling proteins play a direct role in modulating airway smooth muscle reactivity beyond simple metabolic iron storage.** * **Surprising Findings:** The high rank of ferritin heavy and light chains ([FTH1](/details-gene/2495) and [FTL](/details-gene/2512)) as defining markers suggests a function more specialized than ubiquitous housekeeping. This may involve regulating local redox signaling or protecting against ferroptosis in the unique, oxidant-rich environment of the airways. * **Testable Questions:** Does siRNA-mediated knockdown of [FTH1](/details-gene/2495) in cultured human airway smooth muscle cells alter their contractile response to acetylcholine or their susceptibility to apoptosis when challenged with environmental oxidants, such as ozone or cigarette smoke extract?