Comparison of senescence progression in mesenchymal cells from human umbilical cord walls measured by immunofluorescence and flow cytometry of p16 and p21

Einstein (Sao Paulo). 2020 Oct 16:18:eAO5236. doi: 10.31744/einstein_journal/2020AO5236. eCollection 2020.
[Article in English, Portuguese]

Abstract

Objective: To follow the expansion of mesenchymal stem cells from umbilical cords by two classic senescence markers, p16 (INK4A) and p21 (CDKN1A), using practical, fast, and less expensive methods than the gold standard Western blotting technique, to evaluate its applicability in the laboratory.

Methods: Mesenchymal stem cells from umbilical cords were isolated from Wharton's jelly and, after quality control, morphological and immunophenotypic characterization by flow cytometry, were expanded in culture until coming close to cell cycle arrest (replicative senescence).

Results: A comparison was made between young cells, at passage 5, and pre-senescent cells, at passage 10, evaluating the protein expression of the classic cell senescence markers p16 and p21, comparing the results obtained by Western blotting with those obtained by flow cytometry and indirect immunofluorescence.

Conclusion: Follow-up of cell cultures, through indirect p16 immunofluorescence, allows the identification of mesenchymal stem cells from umbilical cord cultures at risk of reaching replicative senescence.

Objetivo: Acompanhar a expansão de células-tronco mesenquimais de cordão umbilical por dois marcadores clássicos de senescência, p16 (INK4A) e p21 (CDKN1A), usando métodos práticos, rápidos e com custo menor do que a técnica padrão-ouro de Western blotting, para avaliar sua aplicabilidade em laboratório.

Métodos: Células-tronco mesenquimais de cordão umbilical foram isoladas da geleia de Wharton e, após controle de qualidade e caracterização morfológica e imunofenotípica por citometria de fluxo, foram expandidas em cultura, até chegarem próximas à parada do ciclo celular (senescência replicativa).

Resultados: Foi feita a comparação entre células jovens, na passagem 5, e células pré-senescentes, na passagem 10, avaliando a expressão proteica dos marcadores clássicos de senescência celular p16 e p21, comparando os resultados obtidos por Western blotting com os obtidos por citometria de fluxo e imunofluorescência indireta.

Conclusão: O seguimento de culturas celulares, por meio da imunofluorescência indireta de p16, permite identificar as culturas de células-tronco mesenquimais de cordão umbilical em risco de atingirem a senescência replicativa.

MeSH terms

  • Biomarkers / blood
  • Blotting, Western
  • Cells, Cultured
  • Cellular Senescence*
  • Cyclin-Dependent Kinase Inhibitor p16
  • Cyclin-Dependent Kinase Inhibitor p21
  • Flow Cytometry / methods*
  • Fluorescent Antibody Technique / methods*
  • Humans
  • Mesenchymal Stem Cells / physiology*
  • Umbilical Cord / physiology*

Substances

  • Biomarkers
  • CDKN1A protein, human
  • CDKN2A protein, human
  • Cyclin-Dependent Kinase Inhibitor p16
  • Cyclin-Dependent Kinase Inhibitor p21