Details for: CL1000692

Cell ID: CL1000692

Cell Name: kidney interstitial fibroblast

Description: A fibroblast that is part of an interstitial compartment of a kidney.

Selected Context(s): Overall

Gene Significance Landscape

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Score:
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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 kidney interstitial fibroblast 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 kidney interstitial fibroblast. 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 kidney interstitial fibroblast. 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 kidney interstitial fibroblast. 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:  kidney interstitial fibroblast (CL1000692)

 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 [kidney interstitial fibroblast](/details-cell/CL1000692) is a mesenchymal cell type residing within the interstitial compartment of the kidney, traditionally associated with producing extracellular matrix and maintaining tissue architecture. The gene significance profile, based on expression specificity (**Overall**), suggests a more complex and specialized role. The highest-scoring markers are mitochondrial ribosomal RNAs [RNR2](/details-gene/4550) and [RNR1](/details-gene/4549), indicating that a unique mitochondrial translational state is a defining characteristic of this cell's identity. Furthermore, a suite of highly specific markers involved in cell-cell communication, scaffolding, and ion transport, such as [MAGI2](/details-gene/9863), [DLG2](/details-gene/1740), and [SLC8A1](/details-gene/6546), points towards a dynamic role in sensing and integrating signals within the renal microenvironment. ## Key Characteristics and Function Analysis of top marker genes, ranked by the Z-score based Cell Significance Index (CSI), reveals several functional clusters that define the [kidney interstitial fibroblast](/details-cell/CL1000692). * **Specialized Mitochondrial State:** The two most specific markers for this cell type are mitochondrial ribosomal RNAs, [RNR2](/details-gene/4550) (CSI: 22.68) and [RNR1](/details-gene/4549) (CSI: 20.96). This high specificity suggests that maintaining a robust capacity for mitochondrial protein synthesis is a core feature of this cell. This may prime the cell for rapid metabolic adaptation or for producing large quantities of proteins, such as collagen, during physiological stress or fibrotic processes. * **Cellular Scaffolding and Adhesion:** A prominent theme is the expression of genes typically associated with cell junctions and signaling scaffolds. These include [MAGI2](/details-gene/9863), a MAGUK-family scaffolding protein involved in cell-cell communication ([Link](https://pubmed.ncbi.nlm.nih.gov/9647693/)), [DLG2](/details-gene/1740), another scaffolding protein involved in clustering channels and receptors ([Link](https://doi.org/10.1016/s0896-6273(00)80284-6)), and the cell adhesion molecules [CNTN1](/details-gene/1272) and [CNTN4](/details-gene/152330). This molecular signature implies a critical role in organizing the interstitial space and forming communication hubs with adjacent cells like tubular epithelia or vascular cells. * **Ion Transport and Calcium Signaling:** The specific expression of ion transporters such as [SLC8A1](/details-gene/6546) (Na+/Ca2+ exchanger) and [CACNA1C](/details-gene/775) (L-type voltage-gated calcium channel), along with the calcium sensor [SYT1](/details-gene/6857), indicates a significant role in regulating calcium homeostasis. This machinery may be crucial for stimulus-contraction coupling, cell migration, or activating calcium-dependent signaling pathways in response to local cues. * **Signal Transduction:** The cell exhibits a distinct profile of signal transduction molecules, including G protein-coupled receptors ([ADGRB3](/details-gene/577), [ADGRL3](/details-gene/23284)) and regulators of G protein signaling like [RGS5](/details-gene/8490). This suggests the cell is highly responsive to a variety of hormones and signaling molecules present in the renal interstitium. * **Exclusion of Core Metabolic and Housekeeping Functions:** A striking finding from the anti-marker list is the significant negative CSI for numerous mitochondrially-encoded genes essential for the electron transport chain, such as [COX1](/details-gene/4512), [COX2](/details-gene/3564), [COX3], [ATP6](/details-gene/4508), [CYTB](/details-gene/4519), and multiple NADH dehydrogenase subunits ([ND1](/details-gene/4535), [ND2](/details-gene/4536), [ND4](/details-gene/4538), [ND5](/details-gene/4540)). Similarly, universally expressed genes like [GAPDH](/details-gene/2597), ubiquitin genes ([UBB](/details-gene/7314), [UBC](/details-gene/7316)), and ferritin subunits ([FTH1](/details-gene/2495), [FTL](/details-gene/2512)) are strongly anti-correlated. This suggests that while these fibroblasts are uniquely defined by their mitochondrial *ribosomes*, their relative expression of core respiratory chain components and other common housekeeping genes is significantly lower compared to other cells, pointing towards a specialized metabolic profile. ## Clinical Significance and Contextual Roles **Overall**, the unique gene signature of the [kidney interstitial fibroblast](/details-cell/CL1000692) provides insights into its potential role in renal health and disease. As the primary cell type responsible for renal fibrosis, understanding its baseline molecular state is crucial. The high specificity of genes involved in cell adhesion and scaffolding ([MAGI2](/details-gene/9863), [DLG2](/details-gene/1740)) suggests that these cells are key organizers of the interstitial microenvironment. Disruption of these interactions could be an early event in the pathogenesis of kidney disease, leading to altered communication between fibroblasts and epithelial or endothelial cells. The expression of [MGP](/details-gene/4256), a potent inhibitor of vascular and soft tissue calcification, is notable. Downregulation of [MGP](/details-gene/4256) in these cells could contribute to the vascular calcification often seen in chronic kidney disease. The expression of genes associated with hemostasis and vascular function, such as [KNG1](/details-gene/3827) (Kininogen 1) and [RGS5](/details-gene/8490) (a regulator of vascular tone), positions these fibroblasts at the interface of blood flow regulation and tissue homeostasis. Changes in the expression of these genes could impact local hemodynamics and contribute to ischemic injury. The unique metabolic state, highlighted by high [RNR1](/details-gene/4549)/[RNR2](/details-gene/4550) expression but low expression of core respiratory genes, may represent a quiescent but 'primed' state. In the context of injury, these cells could rapidly utilize their translational machinery to synthesize and secrete large amounts of extracellular matrix proteins, driving the progression of fibrosis. Targeting this metabolic switch could therefore be a potential therapeutic avenue for anti-fibrotic therapies. ## Potential Mechanisms and Research Directions 1. **Hypothesis: Kidney interstitial fibroblasts exhibit a "primed" metabolic state characterized by high mitochondrial translational capacity but low basal oxidative phosphorylation, enabling rapid activation during fibrogenesis.** * **Surprising Findings:** The cell's most specific markers are mitochondrial ribosomal RNAs ([RNR1](/details-gene/4549), [RNR2](/details-gene/4550)), yet the protein-coding genes for the mitochondrial respiratory chain ([COX1](/details-gene/4512), [ND1](/details-gene/4535), etc.) are among the strongest anti-markers. This apparent contradiction suggests a dissociation between translational potential and constitutive respiratory activity, pointing to a specialized, non-canonical mitochondrial function. * **Testable Questions:** Can metabolic flux analysis confirm a greater reliance on glycolysis in quiescent [kidney interstitial fibroblasts](/details-cell/CL1000692) compared to renal epithelial cells? Furthermore, upon stimulation with pro-fibrotic factors like TGF-β1, is there a rapid and specific upregulation in the translation of mitochondrial-encoded respiratory proteins, preceding the large-scale synthesis of extracellular matrix components? 2. **Hypothesis: Kidney interstitial fibroblasts utilize a "neuronal-like" repertoire of scaffolding and adhesion proteins to form signaling microdomains that function as mechanosensors or chemosensors within the renal interstitium.** * **Surprising Findings:** A fibroblast, a cell type traditionally viewed as primarily structural, is uniquely defined by a suite of scaffolding proteins ([MAGI2](/details-gene/9863), [DLG2](/details-gene/1740)) and cell adhesion molecules ([CNTN1](/details-gene/1272), [CNTN4](/details-gene/152330)) that are best characterized for their roles in organizing the neuronal postsynaptic density and axon guidance. * **Testable Questions:** Does high-resolution imaging of kidney tissue reveal co-localization of [MAGI2](/details-gene/9863) and [DLG2](/details-gene/1740) with ion channels ([SLC8A1](/details-gene/6546), [CACNA1C](/details-gene/775)) and other renal cell types (e.g., tubular epithelia, pericytes) at distinct cell-cell junctions? Could knockout or knockdown of these scaffolding proteins in fibroblast-specific mouse models alter renal responses to physiological stresses like hypertension or diuretic challenge?