Jianqiang Hu’s research while affiliated with First Affiliated Hospital of China Medical University and other places

Background Cisplatin is a widely used drug for the treatment of solid organ cancer, but its renal toxicity cannot be ignored. Amentoflavone (AME), a natural flavonoid compound, has remarkable pharmacological effects, including anti-inflammatory and antioxidative effects. The effect and mechanism of AME on cisplatin-induced acute kidney injury (CI-AKI) remain unclear. Methods We investigated the effect of AME on CI-AKI using the HK-2 cell line and C57BL/6 mice. Renal function, tissue damage, and molecular markers were assessed to explore the effects of AME on oxidative stress and cell death pathways. Results In vitro, AME significantly suppressed the cytotoxic effects of cisplatin on HK-2 cells. Furthermore, AME significantly inhibited cisplatin-induced ferroptosis and PANoptosis (apoptosis, pyroptosis and necroptosis). In mice with acute kidney injury induced by a single intraperitoneal injection of cisplatin, the daily administration of AME during AKI effectively improved renal function and alleviated renal tubular injury, characterized by the normalization of blood urea nitrogen (BUN) and serum creatinine (SCr) levels; it also inhibited cisplatin-induced renal ferroptosis and PANoptosis. AME is a natural antioxidant that activates the Nrf2 antioxidant pathway both in vivo and in vitro. In Nrf2 knockout mice and knockdown cells, the protective effect of AME against cisplatin-induced nephrotoxicity disappeared. However, after Nrf2 knockout, the effect of AME on ferroptosis completely disappeared, and that on PANoptosis partially disappeared. Conclusion Amentoflavone has a protective effect on cisplatin-induced acute kidney injury via a mechanism related to the Nrf2-dependent antioxidant pathway and the regulation of ferroptosis and PANoptosis.

Nrf1 is a transcription factor that is highly conserved and reacts to oxidative, proteotoxic and endoplasmic reticulum stress in cells; nonetheless, its function in the context of acute kidney injury (AKI) remains unclear. Using a model of cisplatin-induced nephrotoxicity in vitro and in vivo, we found that the expression of Nrf1, which is expressed at high levels in renal tubular cells, was significantly downregulated after cisplatin treatment. Proximal tubule-specific Nrf1 knockout worsened and Nrf1 overexpression attenuated cisplatin-induced (CI)-AKI. RNA sequencing analysis revealed that Nrf1 overexpression decreased the number of transcripts involved in cell death, specifically those associated with ferroptosis, after cisplatin treatment. Furthermore, ferroptosis responses, characterized by increased lipid peroxidation and iron content and decreased FPN, XCT and glutathione peroxidase 4 levels, were attenuated in Nrf1-overexpressing HK-2 cells but worsened in Nrf1-knockout mice and Nrf1-knockdown HK-2 cells. Moreover, lipidomic and RNA sequencing results indicated that Nrf1 regulated the levels of polyunsaturated fatty acids (PUFAs) and inhibited the expression of ACSL4. Additionally, ChIP experiments revealed that Nrf1 bound to the promoter region of ACSL4, thereby inhibiting its transcription. Furthermore, inhibitors of ACSL4 significantly reduced the sensitivity of HK-2 cells to ferroptosis induced by Nrf1 knockdown. Collectively, these findings suggest that Nrf1 is a novel target for inhibiting ferroptosis in renal tubule cells by suppressing the transcription and expression of ACSL4, thereby reducing PUFA levels. Consequently, activators developed for Nrf1 may hold therapeutic potential in the treatment of patients with CI-AKI.

Context Oridonin (Ori) possesses anti-inflammatory, antioxidant and antitumor properties. However, the effects of Ori on Lipopolysaccharide (LPS)-induced early pulmonary fibrosis remain unclear. Objective We evaluated the protective effects of Ori on the mice model of pulmonary fibrosis. Materials and methods The BALB/C mice were given LPS (1 mg/kg) or Ori (20 mg/kg) according to experimental grouping. Then the left lung tissues were used for HE, immunohistochemical and Masson staining, and the right lung tissues were used for hydroxyproline measurement and western blot experiments. Bronchoalveolar lavage fluid was collected for Giemsa staining. Results The high levels of hydroxyproline induced by LPS were reduced by Ori treatment. Immunohistochemical staining and western blot analysis showed that Ori inhibited the increased levels of fibrosis-related proteins (α-smooth muscle actin, transforming growth factor-β, Collagen Ⅰ and phosphorylated-smad). Additionally, Ori treatment increased E-cadherin levels and decreased in Snail and Slug levels. Besides, Ori could suppress LPS-induced the infiltration of neutrophils and activation of the NLRP3 inflammasome. In addition, LPS caused the upregulation of NADPH oxidase 4 and exacerbated lung fibrosis. As the activator of NF-E2 related factor-2, Ori exerted protective effects in this animal model. Moreover, Ori reversed the LPS-triggered increases in Beclin-1, P62/sequestosome 1, autophagy related 3 and LC3. Conclusions These findings suggested that Ori protected against LPS-induced early pulmonary fibrosis by inhibiting NLRP3-dependent inflammation, NADPH oxidase 4-dependent oxidative stress, the impaired autophagy and epithelial mesenchymal transformation.

Oxidative stress and inflammation play important roles in pleurisy. Leonurine (Leo) has been confirmed to exert antioxidative and antiinflammatory effects in many preclinical experiments, but these effects have not been studied in pleurisy. The aim of this study was to explore the therapeutic effect and mechanism of Leo in a carrageenan (CAR)‐induced pleurisy model. In this study, we found that the increase of reactive oxygen species (ROS), myeloperoxidase (MPO), and malondialdehyde (MDA) and decrease of glutathione (GSH) induced by CAR could be reversed by the treatment of Leo. Leo effectively reduced the levels of proinflammatory cytokines interleukin‐1β (IL‐1β), tumor necrosis factor‐α (TNF‐α), and the percentages of mature macrophages and increased the levels of antiinflammatory cytokines (IL‐10). Furthermore, Western blotting revealed that Leo significantly activated the Nrf2 pathway to restrain the thioredoxin‐interacting protein/NOD‐like receptor protein 3 (TXNIP/NLRP3) and nuclear factor kappa‐B (NF‐κB) pathways. However, the protective effect of Leo was significantly weakened in Nrf2‐deficient mice. These results indicate that Leo confers potent protection against CAR‐induced pleurisy by inhibiting the TXNIP/NLRP3 and NF‐κB pathways dependent on Nrf2, which may serve as a promising agent for attenuating pleurisy.

Background and purpose: Increasing evidence suggests that ferroptosis plays a key role in the pathophysiology of acute kidney injury (AKI) induced by cisplatin. The Nrf2 signaling pathway regulates oxidative stress and lipid peroxidation and positively regulates cisplatin-induced AKI (CI-AKI). However, its effect as well as an alkaloid compound leonurine hydrochloride (LH) on ferroptosis after CI-AKI remain unclear. Experimental approach: The anti-ferroptotic effects of Nrf2 and LH were assessed using a mouse model of cisplatin-induced AKI. In vitro, the potential effects of LH on erastin- and RSL3-induced HK-2 human PTEC ferroptosis were examined. Key results: As expected, Nrf2 deletion induced ferroptosis-related protein expression and iron accumulation in vivo, further aggravating CI-AKI. LH activated Nrf2 and prevented iron accumulation, lipid peroxidation and ferroptosis in vitro, while these effects were abolished in siNrf2-treated cells. Moreover, LH potently ameliorated cisplatin-induced renal damage, as indicated by the assessment of SCr, BUN, KIM-1, and NGAL. Importantly, LH activated the Nrf2 antioxidative signaling pathway and prohibited changes in ferroptosis-related morphological and biochemical indicators, such as the MDA level, SOD and GSH depletion and GPX4 and xCT downregulation, in CI-AKI. Moreover, Nrf2 KO mice were more susceptible to ferroptosis after CI-AKI than control mice, and the protective effects of LH on AKI and ferroptosis were largely abolished in Nrf2 KO mice. Conclusion and implications: These data suggest that the renal protective effects of Nrf2 activation on CI-AKI are achieved at least partially by inhibiting lipid peroxide-mediated ferroptosis and highlight the potential of LH as a CI-AKI treatment.