Pathogenesis and Molecular Mechanisms of Cholesteatoma

Cholesteatoma is a locally invasive keratinising lesion of the middle ear arising from retraction pockets or epithelial migration, marked by chronic inflammation, abnormal epithelial proliferation and progressive bone destruction. Central to its pathogenesis are interactions between dysregulated immune responses, growth factor signalling and matrix remodelling. Innate immune receptors within the lesion amplify pro-inflammatory cytokines, which drive RANKL-dependent osteoclastogenesis and local bone resorption. Concurrently, aberrant activation of pathways such as EGFR/PI3K/AKT/CyclinD1 and autophagy mechanisms fuel keratinocyte hyperproliferation. Recent evidence has identified specialised fibroblast subsets that secrete activin A to promote osteoclast differentiation, while proteomic studies highlight proteins like α-synuclein as mediators of inflammation and proliferation. The interplay of Th1/Th17 cytokines, damage-associated molecular patterns and matrix metalloproteinases underpins tissue invasion. A detailed understanding of these molecular circuits is guiding the development of targeted therapies to complement or replace surgical management.

Research from Nature Portfolio

Recent studies have harnessed single-cell transcriptomic profiling of human cholesteatoma to reveal a fibroblast subset enriched for inhibin βA expression. These cells secrete activin A, which directly stimulates osteoclast differentiation and bone erosion. Genetic ablation of this pathway in animal models attenuates osteoclastogenesis, while administration of the activin A antagonist follistatin reduces local bone loss, highlighting a novel therapeutic target. Another investigation has elucidated the role of innate immune signalling in lesion progression: elevated Toll-like receptor 4 expression within cholesteatoma correlates with increased TNF-α and IL-1β production, driving RANKL-mediated osteoclast formation and sensorineural impairment. Disruption of TLR4 signalling in experimental models diminishes inflammatory mediator release, prevents excessive bone resorption and preserves auditory function.

Pathogenesis and Molecular Mechanisms of Cholesteatoma publication trend

The graph below shows the total number of articles in pathogenesis and molecular mechanisms of cholesteatoma across all publications each year (not limited to Nature Index journals).

Technical terms

Cholesteatoma: A locally invasive, keratinising squamous epithelial lesion of the middle ear characterized by chronic inflammation and bone erosion.

Single-cell transcriptomics: A technique that profiles gene expression in individual cells to identify distinct cellular subsets and states.

Osteoclastogenesis: The process by which precursor cells differentiate into osteoclasts, the primary bone-resorbing cells.

Activin A: A dimeric member of the transforming growth factor-β superfamily that can promote osteoclast differentiation.

Autophagy: A cellular degradation pathway that recycles cytoplasmic components and can influence cell survival and proliferation.

PI3K/AKT/CyclinD1 signalling pathway: A growth factor–activated cascade that regulates cell cycle progression and survival.

Toll-like receptor 4 (TLR4): An innate immune receptor that recognises microbial components and triggers pro-inflammatory cytokine production.

Damage-associated molecular patterns (DAMPs): Endogenous molecules released by stressed or damaged cells that amplify and perpetuate inflammation.

References

1. Single-cell transcriptomics of human cholesteatoma identifies an activin A-producing osteoclastogenic fibroblast subset inducing bone destruction. Nature Communications (2023).
2. TLR4 drives the pathogenesis of acquired cholesteatoma by promoting local inflammation and bone destruction. Scientific Reports (2015).
3. The Hyperproliferation Mechanism of Cholesteatoma Based on Proteomics: SNCA Promotes Autophagy-Mediated Cell Proliferation Through the PI3K/AKT/CyclinD1 Signaling Pathway. Molecular & Cellular Proteomics (2023).
4. Comparison of Tissue Factors in the Ontogenetic Aspects of Human Cholesteatoma. Diagnostics (2024).
5. Review of potential medical treatments for middle ear cholesteatoma. Cell Communication and Signaling (2022).
6. The Role of EGFR/PI3K/Akt/cyclinD1 Signaling Pathway in Acquired Middle Ear Cholesteatoma. Mediators of Inflammation (2013).