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Updated: Jan 15, 2026
Isolation, Culture, and Characterization of Primary Dermal Fibroblasts from Human Keloid Tissue
Published on: July 28, 2023
Transcriptome profiling of human dermal MDPL fibroblasts reveals a characteristic molecular signature providing
Michela Murdocca1, Gerardo Pepe2, Serena Maccaroni1
1Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy.
Abstract:
The emerging perception that the mammalian dermis encloses fibroblasts with differing functional identities has profound implications for understanding a wide range of genetic pathological states, including aging. MDPL syndrome (mandibular hypoplasia, deafness, progeroid characteristics, and lipodystrophy; MIM #615381) is an extremely rare, genetic progeroid disorder. Patients reported variants in the POLD1 gene (NM_002691.3), encoding for the evolutionarily conserved catalytic subunit of DNA polymerase delta (Polδ). The protein is a critical enzyme reliable for synthesizing nascent DNA strands in the eukaryotic genome. Importantly, Polδ also serves to repair DNA lesions due to mutagen exposure. As the natural history of MDPL still remains poorly known, we have performed RNA sequencing analyses on human dermal fibroblasts (HDFs) of two MDPL patients, heterozygotes for p.Ser605del, compared to WT HDFs. The bioinformatic analyses identify differentially expressed transcripts related to the extracellular matrix of connective tissue and transduction signal markers. Successively, we shed light on the capacity of MDPL cells to respond to and repair DNA damage by comparing transcript levels between X-irradiated MDPL HDFs and non-irradiated ones. Importantly, the results allowed us to identify specific downregulated molecular traits in irradiated MDPL HDFs, including those genes closely involved in the mechanisms of DNA replication and repair. These data were further validated at the functional level, choosing four pivotal proteins (CDC6 (Cell Division Cycle 6), CLSPN (Claspin), XRCC3 (X-Ray Repair Cross Complementing 3), RAD51 (DNA repair protein RAD51 homolog 1)) involved in interconnected pathways ensuring genomic stability. This work provides critical insights into the pathogenesis and the regulatory mechanisms of MDPL syndrome and related diseases, paving the way for future therapeutic interventions. KEY MESSAGES: We identified a molecular signature in MDPL human dermal fibroblasts by transcriptomic profiling. We identified specific markers linked to the extracellular matrix of connective tissue and transduction signal markers. We ascertained in irradiated MDPL human dermal fibroblasts specific downregulated molecular traits, involved in the mechanisms of DNA replication and repair. We validated at functional and biochemical level specific those proteins involved in pathways ensuring genomic stability. The markers identified could be targeted for therapeutic intervention in MDPL syndrome and aging-related diseases.
Insights
MDPL syndrome, a rare genetic disorder, involves DNA polymerase delta (Polδ) variants. Researchers identified molecular signatures in patient fibroblasts, revealing impaired DNA repair mechanisms crucial for genomic stability and potential therapeutic targets.
Area of Science:
- Genetics and Molecular Biology
- Cellular Biology
- Dermatology
Background:
- MDPL syndrome is a rare genetic disorder characterized by mandibular hypoplasia, deafness, progeroid features, and lipodystrophy.
- Variants in the POLD1 gene, encoding DNA polymerase delta (Polδ), are associated with MDPL syndrome.
- Polδ is essential for DNA replication and repair, making its dysfunction critical for genomic integrity.
Purpose of the Study:
- To investigate the molecular mechanisms underlying MDPL syndrome by analyzing gene expression in patient-derived fibroblasts.
- To identify molecular signatures and functional deficits in human dermal fibroblasts (HDFs) from MDPL patients.
- To explore the impact of DNA damage on MDPL HDFs and identify specific molecular alterations.
Main Methods:
- RNA sequencing was performed on human dermal fibroblasts (HDFs) from two MDPL patients and compared to wild-type (WT) HDFs.
- Bioinformatic analyses identified differentially expressed transcripts related to extracellular matrix and signal transduction.
- X-irradiation was used to induce DNA damage, followed by transcriptomic analysis to assess repair capacity in MDPL HDFs.
Main Results:
- Transcriptomic profiling revealed a distinct molecular signature in MDPL HDFs, including altered extracellular matrix and signal transduction markers.
- Irradiated MDPL HDFs showed specific downregulated molecular traits involved in DNA replication and repair pathways.
- Functional validation confirmed alterations in key proteins (CDC6, CLSPN, XRCC3, RAD51) essential for maintaining genomic stability.
Conclusions:
- MDPL syndrome is associated with molecular deficits in DNA replication and repair mechanisms within dermal fibroblasts.
- The identified molecular signature and functional impairments provide insights into MDPL pathogenesis.
- These findings suggest potential therapeutic targets for MDPL syndrome and aging-related diseases.
