ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on X

Kidney Week

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.