Fig 1: Schematic illustration of IL-37 regulating renal fibrosis. In the extracellular space, IL-37 binds to IL-18Ra and recruits the IL-1R8, which can induce CPT1A expression. Intracellular IL-37 upregulates CPT1A expression directly. CPT1A expression contributes to restoration of FAO like increased ATP content and relieved lipid drops accumulation, then decreases the expression of fibrosis markers and inflammatory cytokines level, eventually ameliorates renal fibrosis of DKD.
Fig 2: IL-37 alleviated diabetic proteinuria and phenotype. a-e Pathophysiological parameters in DKD model of wild type (WT) or IL-37tg mice. Urine albumin to creatinine ratio (UACR) (a), SCr and blood urea nitrogen (BUN) (b), serum glucose (c), body weight (d), and ratio of kidney weight to body weight (e). f Relative mRNA level of KIM1 and NGAL in primary renal tubule cells isolated from different groups of mice. Data are mean ± SD. n = 8 mice per group. *p < 0.05, **p < 0.01, ***p < 0.001. NS, statistically nonsignificant.
Fig 3: CPT1A was downregulated in DKD patients and positively correlated with renal functions. a Representative IHC staining of CPT1A in human renal biopsies from control subjects (n = 10) and DKD patients (n = 24). Scale bar, 100 µm. b-f Correlation between relative expression of CPT1A and the area of renal fibrosis (b), SCr (c), 24 h urine protein excretion (d), eGFR (e), or the expression of IL-37 (f) (n = 24) in all subjects. Data are mean ± SD. ***p < 0.001.
Fig 4: IL-37 alleviated renal FAO impairment in mice with DKD. a, b Representative Western blot and IHC staining image of renal CPT1A expression in WT and IL-37tg mice. Scale bar, 100 µm. c ATP level in renal primary tubular epithelial cells of different groups. d Double immunofluorescence staining of ADRP (red) and LTL (green) and oil red O staining with quantification in different groups. e QPCR analysis of the FAO-related genes expression from the mice with or without DKD. Scale bar, 100 µm. Data are mean ± SD. n = 8 mice per group. *p < 0.05, **p < 0.01, ***p < 0.001.
Fig 5: IL-37 was downregulated in DKD patients and was positively correlated with renal functions. a Representative images of immunohistochemical (IHC) staining of IL-37, hematoxylin-eosin (HE) staining, and Masson trichrome staining (MTS) in human renal cortex from control subjects (n = 10) and DKD patients (n = 24). Scale bar, 100 µm. b Serum level of IL-37 in control subjects (n = 10) and subject with DKD (n = 24). c-f Correlation between relative expression of IL-37 in renal and the area of renal fibrosis (c), serum creatinine (SCr) (d), 24 h urine protein excretion (e), or estimated glomerular filtration rate (eGFR) (f) (n = 24) in all subjects. Data are mean ± SD. ***p < 0.001.
Supplier Page from Abcam for Human IL-37 ELISA Kit