title: Vitamin D Attenuates Kidney Fibrosis via Reducing Fibroblast Expansion, Inflammation, and Epithelial Cell Apoptosis.
abstract: Kidney fibrosis is the common final pathway of chronic kidney diseases (CKD). It is characterized by myofibroblast formation, inflammation, and epithelial architecture damage. Vitamin D is known as a renoprotective agent, although the precise mechanism is not well understood. This study aimed to elucidate the effect of vitamin D in fibroblast expansion, inflammation, and apoptosis in kidney fibrosis. We performed unilateral ureteral obstruction (UUO) in male Swiss-Webster background mice (3 months, 30-40 grams) to induce kidney fibrosis. The mice (n=25) were divided into five groups: UUO, 3 groups treated with different oral vitamin D doses (0.125 µg/kg (UUO+VD1), 0.25 µg/kg (UUO+VD2), and 0.5 µg/kg (UUO+VD3), and a Sham operation (SO) group with ethanol 0.2% supplementation. We sacrificed the mice on day14 after the operation and harvested the kidney. We made paraffin sections for histological analysis. Tubular injury and fibrosis were quantified based on periodic acid-Schiff (PAS) and Sirius Red (SR) staining. Immunostaining was done for examination of myofibroblasts (αSMA), fibroblasts (PDGFRβ), TLR4, and apoptosis (TUNEL). We did RNA extraction and cDNA for Reverse transcriptase PCR (RT-PCR) experiment for measuring MCP-1, ICAM-1, TLR4, and collagen 1 expression. TGFβ1 level was quantified using ELISA. We observed a significantly lower levels of fibrosis (p<0.001), tubular injury scores (p<0.001), and myofibroblast areas (p<0.001) in the groups treated with vitamin D compared with the UUO group. The TGFβ1 levels and the fibroblast quantifications were also significantly lower in the former group. However, we did not find any significant difference among the various vitamin D-treated groups. Concerning the dose-independent effect, we only compared the UUO+VD-1 group with SO group and found by TUNEL assay that UUO+VD-1 had a significantly lower epithelial cell apoptosis. RT-PCR analysis showed lower expression of collagen1, as well as inflammation-mediator expression (MCP-1, ICAM-1, TLR4) in the UUO+VD-1 group compared with the SO group. Vitamin D reduces kidney fibrosis through inhibition of fibroblast activation, and ameliorates epithelial cell architecture.
authors: Department of Anatomy, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
authors: Nur
authors: N
authors: Arfian
authors: Department of Physiology, Faculty of Medicine, Universitas Gadjah Mada Yogyakarta, Indonesia.|Department of Physiology, Faculty of Medicine, Universitas Jendral Sudirman, Purwokerto, Indonesia.
authors: Khusnul
authors: K
authors: Muflikhah
authors: Department of Physiology, Faculty of Medicine, Universitas Gadjah Mada Yogyakarta, Indonesia.
authors: Sri Kadarsih
authors: SK
authors: Soeyono
authors: Department of Anatomy, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
authors: Dwi Cahyani Ratna
authors: DC
authors: Sari
authors: Department of Surgery, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
authors: Untung
authors: U
authors: Tranggono
authors: Department of Anatomical Pathology, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
authors: Nungki
authors: N
authors: Anggorowati
authors: Department of Anatomy, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia.
authors: Muhammad Mansyur
authors: MM
authors: Romi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology; D005347:Fibroblasts / Q000187:drug effects / Q000473:pathology; D005355:Fibrosis; D007249:Inflammation / Q000473:pathology / Q000517:prevention & control; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051379:Mice; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D014517:Ureteral Obstruction / Q000473:pathology; D014807:Vitamin D / Q000008:administration & dosage*
chemical_list: C508961:Tgfb1 protein, mouse; D053773:Transforming Growth Factor beta1; D014807:Vitamin D
keywords: Apoptosis; Fibroblast; Inflammation; Kidney fibrosis; Vitamin D