Oxidative dysregulation as central mechanisms of PANDA lncRNA in diabetic vasculature
A Mongelli, A Mengozzi, M Telesca, V Masciovecchio, S Mohammed, A Virdis, A Kiss, C M Matter, F Paneni, F Ruschitzka, S CostantinoAbstract
Background
Long non-coding RNAs (lncRNAs) are critical epigenetic and post-transcriptional regulators of cardiovascular pathophysiology. Through interactions with transcription factors, chromatin complexes, and RNA-binding proteins, lncRNAs modulate gene expression programs governing several cellular pathways.
Purpose
To investigate the molecular mechanism of lncRNA PANDA in diabetic vascular damage.
Methods
RNAseq was performed to vascular specimens from diabetic and control patients as well in human aortic endothelial cells (HAECs) exposed to normal (5 mM, NG) and high (25 Mm, HG) glucose concentrations. PANDA modulations were performed by siRNA and plasmid transfection. RNA-seq was used to unveiled transcriptional changes. Expression of PANDA was assessed by real time qPCR. PANDA RNA immuno-precipitation was performed to check the bindings to relevant transcriptional factors followed by ChiP analysis. Western blot, Immunofluorescence stains, colorimetric assays were performed to investigate on proteins levels, oxidative stress and mitochondrial activity. Organ chambers experiments on human vessels were performed to test the effects of PANDA silencing in diabetic specimens.
Results
RNA-seq analysis identified PANDA among the top up-regulated long non-coding RNAs in vascular specimens from diabetic patients. Consistently, PANDA expression was significantly increased in HAECs exposed to high glucose (HG) compared with normal glucose (NG). PANDA silencing under HG conditions reduced oxidative stress through activation of the NRF2 pathway. Mechanistically, PANDA directly bound to NRF2, impeding its nuclear translocation and subsequent transcription of antioxidant target genes (HMOX1, TFRC1). It results increase mitochondial oxidative stress and ferroptosis as shown by increased levels of lipid peroxidation. Interestingly, PANDA knockdown in HG-treated HAECs attenuated oxidative stress, whereas PANDA overexpression under NG conditions exacerbated oxidative stress damage. In human vessels, PANDA silencing improved endothelium-dependent vasorelaxation, while PANDA overexpression impaired vascular function.
Conclusions
In diabetes, PANDA acts as a molecular decoy that sequesters NRF2, thereby disrupting antioxidant transcriptional programs and promoting reactive oxygen species–driven signaling. These findings identify PANDA as a novel potential therapeutic target in diabetic vascular disease.