Atorvastatin inhibits renal inflammatory response induced by calcium oxalate crystals via inhibiting the activation of TLR4/NF-κB and NLRP3 inflammasome.

This study aimed to investigate the renal protective effect of atorvastatin (ATV) on the kidney inflammation induced by calcium oxalate (CaOx) crystals. A cell model of cell-crystal interactions and a rat model of CaOx kidney stone were established. The expressions of TLR4, NF-κB, NLRP3, and cleaved caspase-1 in cells and rat kidney tissues were detected using Western blot, immunohistochemical, and/or immunofluorescence. The concentrations of malondialdehyde (MDA), superoxide dismutase (SOD), reactive oxygen species (ROS) in cells, and lactic acid dehydrogenase (LDH) in the culture medium were measured. The secreted levels of interleukin (IL)-1β, IL-18, IL-6, and tumor necrosis factor-α (TNF-α) were examined by ELISA. The serum levels of creatinine (CRE) and blood urea nitrogen (BUN) were measured. von Kossa staining was used for the evaluation of renal lens deposition. The CaOx model group showed significantly decreased SOD level; increased concentrations of MDA; ROS and LDH; elevated expressions of TLR4, NF-κB, NLRP3, and cleaved caspase-1; and the elevated release of IL-1β, IL-18, IL-6, and TNF- α as compared to the control group. The treatment with ATV significantly inhibited the formation of CaOx kidney stone by increasing the level of SOD; downregulating MDA, ROS, and LDH; inhibiting the expressions of TLR4, NF-κB, NLRP3 and cleaved caspase-1; and blocking the secretion of inflammatory cytokines. In addition, the serum levels of CRE and BUN, and the intrarenal crystal deposition were also significantly decreased in ATV-treated rats. In summary, oxidative stress, TLR4/NF-κB, and NLRP3 inflammasome pathways are involved in renal inflammatory responses induced by CaOx crystals. ATV treatment significantly suppressed oxidative stress, inhibited the activation of TLR4/NF-κB and NLRP3 inflammasome pathways, and decreased the release of inflammatory mediators, thereby ameliorating CaOx crystal-induced damage and crystal deposition in HK-2 cells and rat kidney tissues.

Sun Y ，Liu Y ，Guan X ，Kang J ，Wang X ，Liu Q ，Li D ，Xu H ，Tao Z ，Deng Y ... -  《-》

Klotho alleviates contrast-induced acute kidney injury by suppressing oxidative stress, inflammation, and NF-KappaB/NLRP3-mediated pyroptosis.

Contrast-induced acute kidney injury (CI-AKI) is a common complication following percutaneous coronary intervention in coronary artery disease (CAD) patients with >30% incidence. Klotho is a multifunctional protein that inhibits oxidative stress and inflammation, but its role in CI-AKI is poorly understood. The present study aimed to explore the effects of klotho in CI-AKI. Six-week-old mice and HK-2 were divided into the control, contrast medium (CM), CM + klotho, and klotho groups. H&E staining evaluated kidney injury. Scr and BUN showed renal function. DHE probe and ELISA kit detected the levels of reactive oxygen species (ROS) in kidney tissue, superoxide dismutase (SOD), and malondialdehyde (MDA) in serum. Western blot detected the expressions of NF-κB and phosphorylated NF-κB (p-NF-κB) and pyroptosis-related protein levels of NLRP3, caspase-1, GSDMD, and cleaved-GSDMD in the kidney of CI-AKI mice. CCK-8 and lactate dehydrogenase (LDH) activity assays determined cell viability and damage. Fluorescent probe dichloro-dihydro-fluorescein diacetate (DCFH-DA) and enzyme-linked immunosorbent assay (ELISA) tested oxidative stress-related indicators. These included intracellular reactive oxygen species (ROS), superoxidase dismutase (SOD), and malondialdehyde (MDA). IL-6, TNF-α, IL-1β, and IL-18 in the cell supernatant were tested by ELISA assay and used to reflect inflammation responses. Propidium iodide (PI) staining showed the cell death of HK-2. The expressions of NF-κB, p-NF-κB and pyroptosis-related protein levels of NLRP3, caspase-1, GSDMD, and cleaved-GSDMD were detected by Western blot. Exogenous klotho administration reduced kidney histopathological alterations and improved renal function in vivo. The levels of reactive oxygen species (ROS) in renal tissue, superoxide dismutase (SOD), and malondialdehyde (MDA) in serum decreased after the klotho intervention. The expression levels of p-NF-κB and pyroptosis-related proteins, including NLRP3, caspase-1, GSDMD, and cleaved-GSDMD, were decreased in CI-AKI mice after the klotho intervention. In vitro, klotho significantly inhibited CM-induced oxidative stress and the production of IL-6 and TNF-α. Moreover, it was found that klotho inhibited the activation of p-NF-κB and down-regulated pyroptosis-related protein (NLRP3, caspase-1, GSDMD, and cleaved-GSDMD). Klotho has a protective effect on CI-AKI via suppressing oxidative stress, inflammation, and NF-κB/NLRP3-mediated pyroptosis that contributes to the potential therapy of CI-AKI.

Fu Y ，Cao J ，Wei X ，Ge Y ，Su Z ，Yu D ... -  《-》

Hydrogen-Rich Saline Attenuated Subarachnoid Hemorrhage-Induced Early Brain Injury in Rats by Suppressing Inflammatory Response: Possible Involvement of NF-κB Pathway and NLRP3 Inflammasome.

Shao A ，Wu H ，Hong Y ，Tu S ，Sun X ，Wu Q ，Zhao Q ，Zhang J ，Sheng J ... -  《-》

[Curcumin alleviates nuclear factor-κB/NOD-like receptor protein 3 mediated renal injury caused by acute respiratory distress syndrome through reducing mitochondrial oxidative stress].

Yang M ，Tian H ，Shen P ，Xu L ，Liu H ，Zhu J ，Wang Q ，Shi Y ... -  《-》

Mechanisms that lead to the regulation of NLRP3 inflammasome expression and activation in human dental pulp fibroblasts.

The NLRP3 inflammasome plays an important role in the cellular defense against invading pathogens and is reported to be expressed in human dental pulp fibroblasts (HDPFs). However, the role of the NLRP3 inflammasome in HDPFs during pulpal infection and inflammation remains unclear. To elucidate the function of the NLRP3 inflammasome and the mechanisms that lead to its expression and activation in HDPFs. The test model used lipopolysaccharide (LPS) and adenosine triphosphate (ATP) to simulate an inflammatory environment. Lentiviral vectors encoding short hairpin RNAs were used to knock down NLRP3 and caspase-1 in HDPFs. Specific inhibitors were used to determine whether the toll-like receptor 4 (TLR4), myeloid differentiating factor 88 (MyD88), or nuclear factor-kappa B (NF-κB) pathways were involved in the regulation of NLRP3 expression. Reactive oxygen species (ROS) production was measured by fluorescent microscopy and flow cytometry using the total ROS/superoxide detection kit. Gene and protein expression were quantified by real-time polymerase chain reaction and Western blot, while cytokine release was measured by an enzyme-linked immunosorbent assay. LPS up-regulated NLRP3 and IL-1β expression while ATP induced the activation of caspase-1 and the release of IL-1β in LPS-primed HDPFs. The knockdown of NLRP3 or caspase-1 expression significantly inhibited IL-1β secretion. Pretreatment with a TLR4 inhibitor, a MyD88 inhibitory peptide, or an I Kappa B alpha (IκBα) phosphorylation inhibitor significantly inhibited LPS-induced NLRP3 and IL-1β expression. ATP potently promoted ROS generation in HDPFs; N-acetyl cysteine inhibited ROS production, caspase-1 activation and IL-1β secretion induced by ATP. Our results demonstrated that the NLRP3 inflammasome in HDPFs is crucial for IL-1β secretion in response to LPS plus ATP. LPS engaged the TLR4/MyD88/NF-κB pathway to enhance NLRP3 and pro-IL-1β expression in HDPFs. ATP promoted the generation of ROS and activated the NLRP3 inflammasome in a ROS-dependent manner.

Zhang A ，Wang P ，Ma X ，Yin X ，Li J ，Wang H ，Jiang W ，Jia Q ，Ni L ... -  《-》