ENHANCED MITOCHONDRIAL BIOGENESIS INCREASES ANTI-OXIDANT ENZYMES AND IMPROVES TISSUE INFLAMMATION IN HUMAN IBD TISSUE

Abstract BACKGROUND In patients with inflammatory bowel disease (IBD), there exists a connection between mitochondrial dysfunction and two key issues: increased oxidative stress and attenuated ATP production. Previously we presented at this meeting the effect of a novel gold-based compound (AuPhos) on enhancing mitochondrial function in attenuating mice colitis (). In the present study we interrogate the effect of AuPhos on mitochondrial biogenesis in biopsies from control and active ulcerative colitis (UC) (Mayo 1-2) patients and normal human colonic epithelial cells (NCM460). We postulate that AuPhos-induced mitochondrial function enhances biogenesis and anti-oxidant levels and improves tissue inflammation in human IBD tissue. METHODS Effects of AuPhos on mitochondrial and anti-oxidant proteins were evaluated in NCM460 cells by western blot (WB) +/- low-dose TNF(1ng/ml). Human colonic biopsy samples (n=3) were collected and treated ex-vivo with vehicle or AuPhos (3h, 4oC), and processed for protein and mRNA analysis by WB and RT-qPCR, respectively. Flow cytometry of mitotracker green quantified mitochondrial mass in NCM460 and intestinal epithelial cells (IECs) from human control and UC tissues (n=3, Mayo 1-2). RESULTS AuPhos increased mitochondrial mass (mitotracker, Fig.1A,1B) and biogenesis protein levels PGC1α, NRF2 and TFAM (Fig.1C) in human intestinal epithelial cells (IECs), biopsies, and in NCM460 cells. Protein analysis in NCM460 cells show that AuPhos increases downstream antioxidant markers such as manganese superoxide dismutase (MnSOD), glutathione peroxidase 4 (GPX4), thioredoxin reductase2 (Trx2), and catalase expression when compared to the TNF or control samples. AuPhos substantially upregulates levels of mitochondria complex (mtCO1, mtCO2 Cox6A1, ATP5A1) and anti-oxidant enzyme (MnSOD, GPX, PRDX-2, -4, and -6) mRNA and protein levels in human colonic biopsies compared to vehicle and TNF treated samples (Fig. 1D). Furthermore, AuPhos reduces tissue cytokine and chemokine mRNA levels (IL1β, MCP1, RankL, and TNFα) in human UC tissues (Fig. 1E). CONCLUSIONS The current study reveals that AuPhos increases mitochondrial biogenesis, mitochondrial complex, and antioxidant enzyme levels in human IBD tissue. THE REDUCTION IN TISSUE CYTOKINES AND CHEMOKINES SUGGESTS THAT ENHANCED MITOCHONDRIAL FUNCTION IMPROVES TISSUE INFLAMMATION. This suggests the potential of AuPhos in treating IBD through the restoration of mitochondrial biogenesis.