X inactive-specific transcript regulates mitochondrial function and neuronal differentiation of stem cells via IGF2BP2/CPT1A axis in models of spinal cord injury

Figure 3 X inactive-specific transcript modulated carnitine palmitoyl transferase 1A expression through interaction with insulin-like growth factor 2 mRNA binding protein 2. A: Cytoplasmic and nuclear RNA fractionation showing that X inactive-specific transcript (XIST) is primarily localized in the nucleus of neural stem cells. GAPDH and U6 served as cytoplasmic and nuclear controls, respectively; B: Bioinformatics prediction from StarBase indicating potential regulation of carnitine palmitoyl transferase 1A (CPT1A) by XIST through the insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) pathway; C: Relative mRNA expression of CPT1A upon XIST knockdown and subsequent rescue by IGF2BP2 knockdown, as determined by real-time quantitative PCR. ^aP < 0.05, si-XIST + negative control vs si-XIST + IGF2BP2; ^bP > 0.05; D: RNA immunoprecipitation assay showing CPT1A enrichment on IGF2BP2, which was reversed by XIST knockdown. ^aP < 0.05, si-negative control vs si-XIST; ^bP > 0.05; E: Analysis of CPT1A mRNA stability, indicating that XIST knockdown reduced CPT1A stability, an effect reversed by IGF2BP2 knockdown. ^aP < 0.05, si-negative control + negative control vs si-XIST + negative control; ^bP > 0.05; ^cP < 0.05, si-XIST + negative control vs si-XIST + IGF2BP2. Data are presented as mean ± SD. XIST: X inactive-specific transcript; NC: Negative control; CPT1A: Carnitine palmitoyl transferase 1A; IGF2BP2: Insulin-like growth factor 2 mRNA binding protein 2.