Enniatin B-1-induced lysosomal membrane permeabilization in mouse embryonic fibroblasts

Autor(es)

Oliveira, Carlos A. F. ^[1] ; Ivanova, Lada ^[2] ; Solhaug, Anita ^[3] ; Faeste, Christiane K. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Anim Sci & Food Engn, Dept Food Engn, BR-13635900 Pirassununga, SP - Brazil

^[2] Norwegian Vet Inst, Chem Sect, POB 750 Sentrum, N-0106 Oslo - Norway

^[3] Norwegian Vet Inst, Toxinol Res Grp, POB 750 Sentrum, N-0106 Oslo - Norway

• Tipo de documento: Artigo Científico
• Fonte: MYCOTOXIN RESEARCH; v. 36, n. 1, p. 23-30, FEB 2020.
• Citações Web of Science: 0

Resumo

The mycotoxin enniatin B-1 (ENN B-1) is widely present in grain-based feed and food products. In the present study, we have investigated how this lipophilic and ionophoric molecule can affect the lysosomal stability and chaperone-mediated autophagy (CMA) in wild-type (WT) and in lysosome-associated membrane proteins (LAMP)-1/2 double-deficient (DD) mouse embryonic fibroblasts (MEF). The cell viability and lysosomal pH were assessed using the Neutral Red (NR) cytotoxicity assay and the LysoSensor (R) Yellow/Blue DND-160, respectively. Changes in the expression of the CMA-related components LAMP-2 and the chaperones heat shock cognate (hsc) 70 and heat shock protein (hsp) 90 were determined in cytosolic extracts by immunoblotting. In the NR assay, LAMP-1/2 DD MEF cells were significantly less sensitive to ENN B-1 than WT MEF cells after 24 h exposure to ENN B-1 at levels of 2.5-10 mu mol/L. Exposure to ENN B-1 at concentrations below the half maximal effective concentration (EC50) (1.5-1.7 mu mol/L) increased the lysosomal pH in WT MEF, but not in LAMP-1/2 DD cells, suggesting that lysosomal LAMP-2 is an early target of ENN B-1-induced lysosomal alkalization and cytotoxicity in MEF cells. Additionally, cytosolic hsp90 and LAMP-2 levels slightly increased after exposure for 4 h, indicating lysosomal membrane permeabilization (LMP). In summary, it appeared that ENN B-1 can destabilize the LAMP-2 complex in the lysosomal membrane at concentrations close to the EC50, resulting in the alkalinization of lysosomes, partial LMP, and thereby leakage of CMA-associated components into the cytosol. (AU)

• Processo FAPESP: 16/10485-0 - Enniatinas: novos "insights" sobre a biotransformação e mecanismos de ação
• Beneficiário: Carlos Augusto Fernandes de Oliveira
• Modalidade de apoio: Bolsas no Exterior - Pesquisa