Fig. 5

HTRA1 promoted the ER-to-Golgi transport and secretion of Col1. A Gene functions enrichment analysis for HTRA1. The 37 DCM samples from GSE116250 were divided into two groups based on the median expression value of HTRA1. The differentially expressed genes (|log(FC)|≥ 0.58, p < 0.05) from two groups were then imported into the Metascape database (https://metascape.org/) for enrichment analysis. B Representative immunofluorescence images showing the distribution of Col1 (orange arrows) in primary cardiac fibroblasts transfected with HTRA1 siRNA. The scale bar indicates 20 μm. C ELISA assays showing the Col1 concentration difference of cell supernatant in cardiac fibroblasts transfected with or without HTRA1 siRNA or HTRA1 plasmid. D Western blot showing the effect of HTRA1 inhibition on col1 protein expression in the whole cell, ER and Golgi apparatus, treated with MG132 (10 µM, 8 h) and CQ (25 µM, 8 h). E Representative immunofluorescence images displaying the colocalization of Col1 and Na + /K + ATP. Orange box represented a typical colocalization field of view. The scale bar indicates 4um. Immunofluorescence assay (left images) exhibiting the colocalization of col1 and GRP94 (F) or GM130 (G) in cardiac fibroblasts treated with or without HTRA1 siRNA. Orange box represented a typical colocalization field of view. The scale bar indicates 4 μm. Middle images showing the intensity of col1 and GRP94/GM130 along with the whit lines. Right box plots quantifying colocalization strength using Pearson’s R. Primary cardiac fibroblasts were treated with TGFβ1 for 48 h