Fig. 1
Neural TD of metastable pericytes occurs in a brief temporal window. a Expression of ATOH1 and MASH1, and VEGFA mRNAs at various time points after exposure of pericytes to hypoxia (coloured: p < 0.01). Values are normalized to normoxic control cells. b Expression of VEGFA, ATOH1, and MASH1 mRNAs at various time points after serum starvation (coloured: p < 0.01). Values are normalized to normoxic control cells in growth medium. c Expression of ATOH1 and MASH1 mRNAs at various time points after exposure of pericytes to N2 medium relative to control cells in growth medium (coloured: p < 0.01). d Immunohistochemical detection of MYOD (top left) and LC3B (top right). Electron micrographs show ultrastructural signature of micro-nucleophagy, an endoplasmic reticulum-derived vesicle surrounded by an autophagic vacuole (arrow). Application of an autophagy reporter plasmid (ptfLC3) confirmed that autolysosomes formed at t = 5 min as evidenced by detection of mRFPlow/GFP+ vesicles and conversion of LC3-I to LC3-II (bottom immunoblots). Transition to mRFPhigh/GFP− state and degradation of LC3-II at t = 15 min indicated near-complete degradation of autolysosomal contents. Scale bars top left 40 μm, top right 20 μm, middle right 0.5 μm, middle left 0.2 μm, bottom 5 μm. Immunoblots show degradation of LC3 and MyoD after initiation of transdifferentiation in pericytes (time points are shown above the blots) [85, 86]. e Schematic demonstration of the proposed model for combined effect of reductive stress (low pO2) and attenuated mechano-transduction on induction of pericyte transdifferentiation. Mechanical cues that sustain the activity of serum response factor (SRF) and an oxidative milieu are required for signalling by SRF co-activator, MICAL2 (microtubule-associated monooxygenase)