Skip to main content
. 2020 Oct 27;7(23):2002261. doi: 10.1002/advs.202002261

Figure 2.

Figure 2

β‐actin −/− (KO) cells secrete HA‐like microcrystals and show enhanced intramitochondrial granules in the early phase of reprogramming. A,C) Live microscopy images of WT and KO cells on day 4. C) Red arrowheads highlight the extracellular crystalline‐like structures in KO cells, A) which are not observed in WT cells (scale bar: 50 µm). B,D) SEM images of the inorganic extracellular components in WT and KO cells on day 4. D) The KO sample shows distinct crystallites and the EDX captured at the structures indicates the presence of Ca (scale bar: 5 µm), B) whereas the WT shows an amorphous structure without any distinct crystallites (scale bar: 50 µm). E,F) EDX spectra on the sample surface in WT and KO cells, showing emission energy (x‐axis) against relative signal intensity (y‐axis). All elements of HA (Ca, P, and O) are identified. Na, Mg, Al, and Si are trace elements from the SEM plate on which the sample was deposited. G–J) TEM images of WT and KO cells at day 2. I) Red arrowheads highlight the extracellular microcrystals structure (scale bar: 2 µm), and J) yellow arrowheads highlight the intramitochondrial granules in KO (scale bar: 500 nm). G,H) No similar structures are observed in WT; H) black arrowheads highlight the mitochondria. K) Quantification of mitochondria with granules in the WT and KO condition at day 2. Counts are based on the TEM images of 24 WT and 22 KO cells, respectively. L,M) Violin plots of VST‐normalized, z‐score‐normalized gene expression data showing L) 1136 mitochondria and M) 68 OXPHOS genes between different timepoints. p‐Values calculated using matched‐pairs two‐tailed t‐test, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, ns p > 0.05. Box plots display the median and interquartile range. N,O) Heatmap of z‐score‐normalized expression data for genes that are DE (p‐adjusted < 0.05) between WT4 and KO4 and part of the mitochondria (n = 1136) and OXPHOS GO terms (n = 68). Hierarchical clustering was performed using Ward's linkage using N) k = 4 clusters for mitochondria and O) k = 6 for OXPHOS.