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Abstract: SA-PO679

The Response of Mesothelial Cells to Fibrotic Stress Is Influenced by Carnitine Acetyltransferase (CrAT)

Session Information

  • Home Dialysis - II
    November 04, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

  • 802 Dialysis: Home Dialysis and Peritoneal Dialysis

Authors

  • Masola, Valentina, Department of Biomedical Science, University of Padova, Padova, Italy
  • D'Apolito, Luciano, Biogem, Institute of Molecular Biology and Genetics,, Ariano Irpino, Italy
  • D'Alessandro, Angelo, Department of Biochemistry and Molecular Genetics, University of Colorado, Denver – Anschutz Medical Campus, Aurora, Colorado, United States
  • Bonomini, Mario, Department of Medicine, University “G. d’Annunzio” of Chieti-Pescara, Chieti, Italy
  • Capasso, Giovambattista, Biogem, Institute of Molecular Biology and Genetics,, Ariano Irpino, Italy
  • Trepiccione, Francesco, Biogem, Institute of Molecular Biology and Genetics,, Ariano Irpino, Italy
  • Onisto, Maurizio, Department of Biomedical Science, University of Padova, Padova, Italy
  • Prosdocimi, Tommaso, Iperboreal Pharma Srl, Pescara, Italy
  • Divino-Filho, Jose C., Division of Renal Medicine, CLINTEC, Karolinska Institutet, Stockholm, Sweden
  • Arduini, Arduino, Iperboreal Pharma Srl, Pescara, Italy
Background

Long exposure to high glucose in peritoneal dialysis (PD) can lead to peritonel fibrosis (PF), resulting in a decline in ultrafiltration capacity. Transforming growth factor-beta (TGF-beta) plays a crucial role in PF, and it is influenced by the hyper-glycolytic state induced by glucose-based PD solutions. Now, new biocompatible PD solutions is being developed, incorporating two complementary approaches: reducing glucose and use osmotic-metabolic agents that offer metabolic benefits to counteract excessive local and systemic glucose exposure. One such agent is L-carnitine. This study aims to investigate the impact of L-carnitine and carnitine acetyltransferase (CrAT), a key enzyme in L-carnitine metabolism, on the modulation of TGF-beta's pro-fibrotic effects.

Methods

CrAT overexpression in mesothelial cells (Met5A) was obtained by a transfection of a plasmid encoding CrAT ORF. The expression of CrAT was assessed at both the gene and protein level using real-time PCR and Western blot. Metabolomic analyses were conducted on WT and CrAT-overexpressing cells. Wild-type (WT) and CrAT-overexpressing cells were also exposed to different concentrations of L-carnitine (50 μM and 2 mM) in the presence and absence of TGF-beta. The expression of markers associated with PF and inflammation was examined.

Results

CrAT overexpression was confirmed and unsupervised hierarchical clustering analysis revealed distinct metabolic profiles between WT and CrAT-overexpressing cells. Notably, their response to TGF-beta differed: treatment with TGF-beta at a physiological L-carnitine concentration (50 μM) significantly increased the expression of fibrotic and pro-inflammatory markers, alpha-SMA, vimentin, IL-6 and IL-1β in WT cells. The exposure to supra-physiological L-carnitine levels reduced the increase of these markers in WT cells. In CrAT-overexpressing cells, TGF-beta failed to modulate alpha-SMA, VIM, IL-6, and IL-1β.

Conclusion

CrAT overexpression could provide valuable insights into the mechanisms by which L-carnitine metabolism effectively regulates the progression of fibrosis and inflammation in PD. Utilizing L-carnitine as an osmo-metabolic agent in PD solutions has the potential to significantly decelerate the advancement of PF.