Fig 1.
Flow diagram of the selected study population.
Table 1.
Baseline characteristics of the study population.
Table 2.
Clinical factors associated with mildly elevated serum bilirubin level.
Fig 2.
The renal outcome of the study patients.
A) Kaplan-Meier survival curves of renal survival in terms of the primary outcomes. The x-axis shows the duration from the coronary CT angiography scan by years, and the y-axis shows the percent survival. B) Penalized spline models reveal the relationship between the baseline total serum bilirubin levels and the risk of primary outcomes. The linear line indicates the hazard ratio curve according to the bilirubin levels, and the gray broken lines above and below the linear line indicate the 95% confidence interval of the hazard ratio. The vertical dotted gray line indicates the serum bilirubin level of 0.8 mg/dL, which is the cut-off value for the study group in the current study.
Table 3.
Clinical factors associated with primary outcome in the study cohort.
Fig 3.
In vivo study in C57BL/6 mice.
A) Study protocol and plasma bilirubin levels after intraperitoneal bilirubin administration. B) Representative images of histologic findings and the tubulointerstitial lesion index; left: the vehicle group, right: the bilirubin treated group, lower: a kidney after UUO surgery, upper: a contralateral (sham) kidney. C) Quantitative real-time PCR results for TGF-β and FSP1. CTL, control group; UUO, unilateral ureteral obstruction; Bil, bilirubin; hTECs, human tubular epithelial cells; NS, nonspecific; *P < 0.05, **P < 0.01. Each condition was evaluated in quadruplicate, and this figure represents one of four independent experiments.
Fig 4.
A) Representative images of hTEC identification by immunofluorescence staining for CD31 as the endothelial cell marker, CD90 as the mesangial cell marker, and CK-18 as the proximal tubular cell marker. B) Representative differential interference contrast images of hTECs showing the morphological changes in hTECs cultured with rTGF-β in the presence or absence of bilirubin. Upper left picture: control group; upper right picture: hTECs cultured with rTGF-β; lower left picture: hTECs cultured with rTGF-β and 0.85 μmol/L bilirubin; lower right picture: hTECs cultured with rTGF-β and 1.7 μmol/L bilirubin. C) Representative immunofluorescence images of hTECs stained with AQP1. D) Representative immunofluorescence images of hTECs stained with DAPI, fibronectin and collagen 1. E) Western blot immunoassay for fibronectin and β-actin. F) Representative images of cell integrity assay. Live red dye for permeant cell membrane which marks both for live and dead cells, dead green dye for impermeant cell outer membrane and stains only cells with disrupted integrity G) Quantitative real-time PCR results for fibronectin, Snail2, Bcl-2, and Bax2. CTL, control, Bil, bilirubin.*P < 0.05, **P < 0.01, ***P < 0.005. Each condition was evaluated in triplicate, and this figure represents one of three independent experiments.