Investigating on the influence mechanism of sausage of sea bass on calcium absorption and transport based on Caco-2 cell monolayer model

Abstract

A monolayer Caco-2 cell model was established to explore the effects of sea bass sausage digestive juice containing phosphate on calcium ion transport. Differential proteins of Caco-2 cells treated with fish sausage juice were detected and analyzed by gene ontology (GO) functional annotation and kyoto encyclopedia of genes and genomes (KEGG) pathway analyses. Results revealed that after treatment with 0.23 mg/mL digestive juice of perch sausage in vitro, Caco-2 cell viability was the highest at 72 h (99.84%). Additionally, 0.23 mg/mL digestive juice of perch sausage in vitro significantly increased calcium ion transport. The transfer volume was 1.396 μg/well. Fish sausages containing phosphate significantly affected the protein expression levels of Caco-2 cells. Two hundred one differential proteins were detected, including 114 up-regulated and 87 down-regulated proteins. The main differential proteins included P02795, Q9P0W0, Q96PU5, Q9GZT9 and Q5EBL8. The adjustment ratios of the fish sausage group were 0.7485, 1.373, 1.2535, 0.6775, and 0.809, respectively. The pathway analysis showed that phosphate affected calcium ion absorption and transport through the P02795 enrichment pathway. The fish sausage group showed that the immune-related functions of cells were affected. This study expounds the effects of water-retaining agents on the nutritional quality of aquatic products and provides theoretical support for the research and application of surimi products.

Keywords: Caco-2 cell; calcium ion transport; pathway analysis; proteomics; sea bass sausages.

Figure 1

The impact of in vitro digestive juice of bass on the viability of Caco-2 cells.

Figure 2

(A) The morphological observation of Caco-2 cells by scanning electron microscope; (B–D) is the morphological changes of Caco-2 cells in different culture time.

Figure 3

Trend of monolayer transmembrane resistance of Caco-2 cell during different culture periods, and transmittance of fluorescein sodium in different culture time: Transmittance of sodium fluorescein from AP side to BL side.

Figure 4

The calcium transport through Caco-2 cell monolayer model of simulated digestive fluid of bass sausage in vitro. Comparison among the three groups: *P < 0.05.

Figure 5

(A) The number of peptides matched to proteins; (B) is the statistical diagram of protein identification coverage.

Figure 6

The volcano map of differentially expressed proteins; (A) is the volcano map of control group vs. fish sausage group; (B) is the volcano map of positive control group vs. fish sausage group; (C) is the volcano map of control group vs. positive control group; (D) is the number of up-and down-regulated differential proteins in each comparison group.

Figure 7

(A) The GO enrichment analysis of differentially expressed proteins (cell components); (B) is the GO enrichment analysis of differentially expressed proteins (biological process); (C) is the GO enrichment analysis of differentially expressed proteins (molecular function).

Figure 8

(A) The GO bubble map of differential proteins between control (0 mg/mL phosphate residue) and fish sausage group (0.13 mg/L phosphate residue); (B) is the GO bubble map of differential proteins between positive control (1 mg/L phosphate residue) and control group (0 mg/L phosphate residue).

Figure 9

(A) The GO chord diagrams of differential proteins between control (0 mg/L phosphate residue) and fish sausage group (0.13 mg/L phosphate residue); (B) is the GO chord diagrams of differential proteins between control (0 mg/L phosphate residue) and positive control group (1 mg/1L phosphate residue).