Research Paper Volume 9, Issue 5 pp 1453—1469

Aged induced pluripotent stem cell (iPSCs) as a new cellular model for studying premature aging

Figure 3. Reduced levels of emerin, and nesprin-2 are associated to the youth and stemness, whereas low expression of lamin B1 is associated to senescence. (A) Emerin was mildly polymerized and interdispersed around the nuclear rim in colony y-iPSCs (asterisk) but normally distributed and expressed in differentiated cells; emerin expression increased upon aging although it keeps mislocalized around nuclei (arrows), whereas lamin B1 decreased. Z reconstructions of high magnification of the insets (right column). (B) Mean fluorescence intensity of emerin immunostained nuclei of colony (clone) and differentiated (diff) cells from y-iPSCs and from a-iPSCs cultures. Data are presented as the mean ± SEM (*: p < 0,05). (C) Mean fluorescence intensity of lamin B1 immunostained nuclei of colony (clone) and differentiated (diff) cells from y-iPSCs and from a-iPSCs nuclei (*: p < 0,05). (D) Lamin A/C and nesprin-2 immunoexpression in colony cells (asterisk) and differentiated cells (arrow) of y-iPSCs, and in aged cells. High magnification of the insets (right column) concerning the nesprin-2 distribution. (E) Mean fluorescence intensity of nesprin-2 labeled nuclei of colony (clone) and differentiated (diff) cells from y-iPSCs and from a-iPSCs cultures (*: p < 0,05) (F) Relative expression levels of LMNB1 mRNA in y-iPSCs and a-iPSCs showing higher levels in y-iPSCs compared to senescent cells (*: p < 0,05, n=3). (G) RT-PCR analysis of EMD mRNA detected higher levels in senescent cells (*: p < 0,05, n=3). (H) Relative expression levels of SYNE2 mRNA in y-iPSCs and a-iPSCs (*: p <0,05, n=3).