Fig. 8

Inhibition of PKM1/2 impairs GACAT2 overexpression-rescued mitochondrial function and cementoblastic differentiation of PDLSCs. The cells were transfected with ov-NC or ov-GACAT2 and incubated in medium with both inflammatory cytokines and EMD (inflammatory environment), and both ov-NC- and GACAT2-transfected cells were then further transfected with si-NC or si-PKM1/2. a OCR of PDLSCs determined by a Seahorse Bioscience XF Analyzer; arrows indicate the sequential injection of 1 μmol·L⁻¹ Oligo, 1 μmol·L⁻¹ FCCP and 2 μmol·L⁻¹ R/A. b Quantification of cellular respiration (basic OCR value prior to Oligo injection), maximal respiration (differences between the maximum rate measurement after FCCP injection and the minimum rate measurement after R/A injection) and ATP production (difference between the final rate measurement prior to Oligo injection and the minimum rate measurement after Oligo injection) of PDLSCs. c mtROS levels in PDLSCs determined with the aid of a MitoSOX probe (flow cytometric analysis). d Quantification of mtROS levels (reflected by the relative fluorescence intensity of MitoSOX). e Intracellular ATP contents (ATP assay). f Relative cementoblastic differentiation-related gene expression levels of BSP, CAP and CEMP-1 determined by qRT-PCR. g Relative cementoblastic differentiation-related protein expression of BSP, CAP and CEMP-1 determined by western blots. h Semiquantitative analysis of protein expression levels (normalized to β-actin) in terms of the relative gray density. i The diagram shows that the lncRNA GACAT2 plays a central role in regulating mitochondrial function and cementoblastic differentiation of PDLSCs in an inflammatory environment. Mechanistically, it functions by binding to PKM1/2 proteins to modulate cell mitochondrial bioenergetics and/or metabolism. The data are shown as the mean ± SD for n from 3 to 8; *P < 0.05, **P < 0.01 and ***P < 0.001 indicate significant differences between the indicated columns