1. Academic Validation
  2. Renoprotective effect of rosmarinic acid by inhibition of indoxyl sulfate-induced renal interstitial fibrosis via the NLRP3 inflammasome signaling

Renoprotective effect of rosmarinic acid by inhibition of indoxyl sulfate-induced renal interstitial fibrosis via the NLRP3 inflammasome signaling

  • Int Immunopharmacol. 2024 May 23:135:112314. doi: 10.1016/j.intimp.2024.112314.
Tung-Wei Hung 1 Yi-Hsien Hsieh 2 Hsiang-Lin Lee 3 Yi-Hsuan Ting 4 Chu-Liang Lin 4 Wen-Wan Chao 5
Affiliations

Affiliations

  • 1 School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan; Division of Nephrology, Department of Medicine, Chung Shan Medical University Hospital, Taichung 40201, Taiwan.
  • 2 Institute of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan; Department of Medical Research, Chung Shan Medical University Hospital, Taichung 40201, Taiwan.
  • 3 School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan; Deptartment of Surgery, Chung Shan Medical University Hospital, Taichung 40201, Taiwan.
  • 4 Institute of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan.
  • 5 Department of Nutrition and Health Sciences, Kainan University, Taoyuan 33857, Taiwan. Electronic address: wwchao@mail.knu.edu.tw.
Abstract

We previously reported that rosmarinic acid (RA) ameliorated renal fibrosis in a unilateral ureteral obstruction (UUO) murine model of chronic kidney disease. This study aimed to determine whether RA attenuates indoxyl sulfate (IS)-induced renal fibrosis by regulating the activation of the NLRP3 inflammasome/IL-1β/Smad circuit. We discovered the NLRP3 inflammasome was activated in the IS treatment group and downregulated in the RA-treated group in a dose-dependent manner. Additionally, the downstream effectors of the NLRP3 inflammasome, cleaved-caspase-1 and cleaved-IL-1β showed similar trends in different groups. Moreover, RA administration significantly decreased the ROS levels of Reactive Oxygen Species in IS-treated cells. Our data showed that RA treatment significantly inhibited Smad-2/3 phosphorylation. Notably, the effects of RA on NLRP3 inflammasome/IL-1β/Smad and fibrosis signaling were reversed by the siRNA-mediated knockdown of NLRP3 or Caspase-1 in NRK-52E cells. In vivo, we demonstrated that expression levels of NLRP3, c-caspase-1, c-IL-1β, collagen I, fibronectin and α-SMA, and TGF- β 1 were downregulated after treatment of UUO mice with RA or RA + MCC950. Our findings suggested RA and MCC950 synergistically inhibited UUO-induced NLRP3 signaling activation, revealing their renoprotective properties and the potential for combinatory treatment of renal fibrosis and chronic kidney inflammation.

Keywords

Indoxyl sulfate; MCC950; NLRP3 inflammasome; Rosmarinic acid; Unilateral ureteral obstruction.

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