Polyploidy and nuclear phenotype characteristics of cardiomyocytes from diabetic adult and normoglycemic aged mice

Autor(es)

Silva, Isabela S. ^[1] ; Ghiraldini, Flavia G. ^[1] ; Veronezi, Giovana M. B. ^[1] ; Mello, Maria Luiza S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Biol, Dept Struct & Funct Biol, UNICAMP, BR-13083862 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ACTA HISTOCHEMICA; v. 120, n. 2, p. 84-94, 2018.
• Citações Web of Science: 2

Resumo

The frequency of polyploid nuclei in the aging human heart is in sharp contrast with that in the human liver. An inverse pattern exists between the mouse heart and liver cells. Ploidy degrees in mouse hepatocytes under hyperglycemic conditions are elevated to higher levels than those in aged hepatocytes. In this study, image analysis cytometry was used to investigate the effect of diabetes and aging on Feulgen-DNA quantities, ploidy degrees, nuclear shapes and chromatin texture in mouse cardiomyocytes compared to previously reported data for mouse hepatocytes. Adult, non-obese diabetic (NOD) hyperglycemic and normoglycemic females and 56 week-old normoglycemic BALB/c females were used. A small percentage (similar to 7%) of the cardiomyocyte nuclei in severely hyperglycemic NOD adult mice possessed higher ploidy values than those in the 8-week-old nonnoglycemic mice. Surprisingly, the Feulgen-DNA values and the frequency of nuclei belonging to the 4C and 8C ploidy classes were even higher (similar to 6%) in normoglycemic NOD specimens than in age-matched hyperglycemic NOD specimens. Additionally, a pronounced elongated nuclear shape was observed especially in adult normoglycemic NOD mice. In conclusion, NOD mice, irrespective of their glycemic level, exhibit a moderate increase in ploidy degrees within cardiomyocyte nuclei during the adult lifetime. As expected, aging did not affect the Feulgen-DNA values and the ploidy degrees of cardiomyocytes in BALB/c mice. The differences in ploidy degrees and chromatin textures such as absorbance variability and entropy, between adult NOD and aged BALB/c mice are consistent with other reports, indicating dissimilarities in chromatin functions between diabetes and aging. (AU)

• Processo FAPESP: 10/50015-6 - Estrutura e organização da cromatina com o envelhecimento e o diabetes frente a alterações induzidas em marcadores epigenéticos
• Beneficiário: Maria Luiza Silveira Mello
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 08/58067-5 - Efeitos do envelhecimento e do diabetes mellitus do tipo I sobre a estrutura da cromatina de hepatócitos de camundongos
• Beneficiário: Flávia Gerelli Ghiraldini
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto