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Panamarova, M.

Publications and source records attributed to Panamarova, M..

3 recordsLinked to original sources

Function-driven geometry directs human pilosebaceous unit development

Single-cell technologies have generated cell censuses of tissues, however, how tissue geometry reflects functional needs remains poorly characterized. The human pilosebaceous unit offers a tractable model, a prenatally-formed complex mini-organ combining hair and sebum production with a stem cell reservoir. Using histomorphology, spatial transcriptomics, and single-cell multiomics on the same human prenatal scalp skin samples (8-19 post-conception weeks), integrated and analyzed using machine learning approaches, we built a spatiotemporal map of pilosebaceous unit development. We demonstrate that epithelial-mesenchymal interactions coordinate cellular fate and organogenesis, using an in vitro hair-bearing skin organoid model to validate this tissue-patterning. In addition, we show sebaceous gland developmental programmes are overcome during tumor formation. Our large-scale multi-modal analysis provides a unique framework for understanding form and function of tissues with applications in tissue engineering and pathology.

developmental biology↗

CEBPβ regulates myoblast proliferation and myogenic differentiation during human myogenesis and rescues defective differentiation in FSHD

CCAAT enhancer binding protein {beta} (CEBPB) is a member of the bZIP transcription factor family and is expressed in many cell types. Whilst CEBPB has been shown to regulate the function of murine satellite cells, the resident skeletal muscle stem cell, however little is known of its role in human myogenesis and muscle disease. We report that CEBPB is expressed in proliferating human myoblasts but swiftly down-regulated upon myogenic differentiation. Interestingly, either over-expression or knock-down of CEBPB inhibit the proliferation rate of human myoblasts. Down-regulation of CEBPB upon myogenic differentiation is then necessary for subsequent myogenic differentiation and fusion into multinucleated myotubes. In the muscle disease context, CEBPB protein levels are increased in myoblasts derived from facioscapulohumeral muscular dystrophy (FSHD) patients. Knock-down of CEBPB in FSHD myoblasts improves myogenic differentiation. In summary, we show that CEBPB is a regulator of human myogenesis and altered CEBPB expression may contribute to defective myogenesis in FSHD.

cell biology↗

Lymphocytes contribute to DUX4 target genes in FSHD muscle biopsies

Facioscapulohumeral muscular dystrophy (FSHD) is an incurable myopathy linked to overexpression of DUX4. However, DUX4 is difficult to detect in FSHD myoblasts and target gene expression is not a consistent FSHD muscle biopsy biomarker, displaying efficacy only on pathologically inflamed samples. Immune gene misregulation occurs in FSHD muscle biopsies with DUX4 targets enriched for inflammatory processes. However, assessment of the FSHD immune cell transcriptome, and the evaluation of DUX4 and target gene expression has not yet been performed. We show that FSHD lymphoblastoid cell lines (LCLs) display robust DUX4 expression, and express early and late DUX4 targets. Moreover, genes elevated on FSHD LCLs are elevated in FSHD muscle biopsies, correlating with DUX4 target activation and histological inflammation. These genes are importantly unaltered in FSHD myoblasts/myotubes, implying a non-muscle source in biopsies. Our results indicate an immune cell source of DUX4 and target gene expression in FSHD muscle biopsies.

bioinformatics↗