Cellular heterogeneity and biomarker discovery

Heterogeneous neural cell types

Every tissue in the body is composed of multiple cell types that vary in their gene and protein expression in a spatiotemporal pattern. Adipose-derived stem cells (ASCs) are a population of special interest due to their potential application for treating musculoskeletal tissue damage and disease. Our lab investigates cellular heterogeneity in these and other cell populations to better understand the behavior of specific cell types. Average measures of mixed cell populations mask the unique characteristics of minor cell types. We have explored cellular characteristics spanning mechanophenotype, gene expression, and traditional surface proteins towards the goal of enriching targeted cell types, including function-specific stem/stromal cells. These approaches have the potential to generate tailored stem cell populations that can perform a given function with a predictable baseline level, lessening the current problems with unstandardized cell sources used in regenerative medicine therapies.

  1. Parsons AM, Ahsan N, Darling EM. (2025) Identifying immunomodulatory subpopulations of adipose stromal vascular fraction and stem/stromal cells through single-cell transcriptomics and bulk proteomics. Stem Cell Rev Rep. PMID: In process. DOI: In process
  2. Dempsey ME, Chickering GR, González-Cruz RD, Fonseca VC, Darling EM. (2022) Discovery of surface biomarkers for cell mechanophenotype via an intracellular protein-based enrichment strategy. Cell Mol Life Sci. 79(320). PMCID: PMC9239330. DOI: 10.1007/s00018-022-04351-w
  3. Dempsey ME, Woodford-Berry O, Darling EM. (2021) Quantification of antibody persistence for cell surface protein labeling. Cell Mol Bioeng. 14: 267-277. PMCID: PMC8175540. DOI: 10.1007/s12195-021-00670-3
  4. Parsons AM, Darling EM. (2021) Temporal responsiveness of adipose-derived stem/stromal cell immuneplasticity. Exp Cell Rep. Preprint release 07/2022. DOI: 10.1016/j.yexcr.2021.112738
  5. Sarnik SA, Sutermaster BA, Darling EM. (2020) Mass-Added Density Modulation for Sorting Cells Based on Differential Surface Protein Levels. Cytometry Part A. PMCID: PMC7855113. DOI: 10.1002/cyto.a.24192
  6. Sadick JS, Crawford LA, Cramer HC, Franck C, Liddelow SA, Darling EM. (2020) Generating Cell Type-Specific Protein Signatures from Non-symptomatic and Diseased Tissues. Annals of Biomedical Engineering. 4(8): 2218-2232. PMCID: PMC7416432. DOI: 10.1007/s10439-020-02507-y
  7. Sutermaster BA, Darling EM. (2019) Considerations for high-yield, high-throughput cell enrichment: fluorescence versus magnetic sorting. Sci Rep. 9: 227 (2019). PMCID: PMC6338736. DOI: 10.1038/s41598-018-36698-1
  8. Parsons AM, Ciombor M, Liu P, Darling EM. (2018) Regenerative potential and inflammation-induced secretion profile of human adipose-derived stromal vascular cells are influenced by donor variability and prior breast cancer diagnosis. Stem Cell Rev Rep. PMCID: PMC6014910
  9. González-Cruz RD, Sadick JS, Fonseca VC, Darling EM. (2018) Nuclear lamin protein C is linked to lineage-specific, whole-cell mechanical properties. Cell Mol Bioeng. 11(2): 131-142. PMCID: PMC5943047. DOI: 10.1007/s12195-018-0518-y PMCID: PMC5943047. DOI: 10.1007/s12195-018-0518-y
  10. Dempsey ME*, Marble HD*, Shin T, Fawzi NL, Darling EM. (2018) Synthesis and characterization of a magnetically active 19F molecular beacon. ACS Bioconjug Chem. 29(2): 335-342. PMCID: PMC5821531. DOI: 10.1021/acs.bioconjchem.7b00671 (*Co-first authors)
  11. Sadick JS, Darling EM. (2017) Processing fixed and stored adipose-derived stem cells for quantitative protein array assays. Biotechniques. 63(6): 275-280. PMCID: PMC5731247. DOI: 10.2144/000114620
  12. Sadick JS, Boutin ME, Hoffman-Kim D, Darling EM. (2016) Protein characterization of intracellular target-sorted, formalin-fixed cell subpopulations. Sci Rep. 6: 33999. PMCID: PMC5036045. DOI: 10.1038/srep33999
  13. Darling EM, DiCarlo D. 2015. High-throughput assessment of cellular mechanical properties. Ann Rev Biomed Eng. 17:35-62. PMCID: PMC8204286. DOI: 10.1146/annurev-bioeng-071114-040545
  14. Beane OS, Darling LEO, Fonseca VC, Darling EM. (2016) Disparate response to methotrexate in stem versus non-stem cells. Stem Cell Rev Reports. 12 (3): 340-51Wet bench research. PMCID: PMC4880537
  15. Labriola NR, Darling EM. (2015) Temporal heterogeneity in single-cell gene expression and mechanical properties during adipogenic differentiation. J Biomech. 48 (2015): 1058-66. PMCID: PMC4380682
  16. Beane OS, Fonseca VC, Cooper LL, Koren G, Darling EM. (2014) Impact of aging on the regenerative properties of bone marrow-, muscle-, and adipose-derived mesenchymal stem/stromal cells. PLoS ONE. 9(12): e115963. PMCID: PMC4277426
  17. Marble HD, Sutermaster BA, Kanthilal M, Fonseca VC, Darling EM. (2014). Gene expression-based enrichment of live cells from adipose tissue produces subpopulations with improved osteogenic potential. Stem Cell Res Ther. 5(5):145. PMCID: PMC4619280. DOI: 10.1186/scrt502
  18. Beane OS, Fonseca VC, Darling EM. (2014) Adipose-derived stem cells retain their regenerative potential after methotrexate treatment. Exp Cell Res. 327 (2014): 222-233. PMCID: PMC4164584.
  19. Kanthilal M, Darling EM. (2014). Characterization of mechanical and regenerative properties of human, adipose stromal cells. Cell Mol Bioeng. 7 (4): 585-97. PMCID: PMC4255916. DOI: 10.1007/s12195-014-0350-y
  20. Desai HV, Voruganti IS, Jayasuriya C, Chen Q, Darling EM. (2014). Live-cell, temporal gene expression analysis of osteogenic differentiation in adipose-derived stem cells. Tissue Eng Pt A. 20(5-6): 899-907. PMCID: PMC3938923. DOI: 10.1089/ten.TEA.2013.0761
  21. González-Cruz RD, Darling EM. (2013). Adipose-derived stem cell fate is predicted by cellular mechanical properties. Adipocyte. 2 (2): 87-91. PMCID: PMC3661107. DOI: 10.4161/adip.23015
  22. González-Cruz RD, Fonseca VC, Darling EM. (2012). Cellular mechanical properties reflect differentiation potential of adipose-derived mesenchymal stem cells. Proc Natl Acad Sci USA. 109 (24): E1523-9. PMCID: PMC3386052. DOI: 10.1073/pnas.1120349109
  23. Darling EM, Guilak F. (2008) A neural network model for cell classification based on single-cell biomechanical properties. Tissue Eng Part A. 14 (9): 1507-1515. PMCID: PMC2748927. DOI: 10.1089/ten.tea.2008.0180
  24. Darling EM, Topel M, Zauscher S, Vail TP, Guilak F. (2008) Viscoelastic properties of human mesenchymally-derived stem cells and primary osteoblasts, chondrocytes, and adipocytes. J Biomech. 41 (2): 454-464. PMCID: PMC2897251