ABSTRACT
Lupus nephritis (LN) is a type of immune-complex nephritis caused by systemic lupus erythematosus and is a major contributor to mortality and morbidity. Honokiol (HNK) has been found to have a therapeutic effect on LN, but its action mechanism remains unclear. In this study, we first demonstrated that HNK attenuates kidney injury in MRL/lpr mice. Results from RNA sequencing combined with ingenuity pathway analysis suggested that HNK plays an anti-LN role through inhibition of the NLRP3 inflammasome and IL33. GEO chip data, single-cell data, and clinical samples from LN patients demonstrated that the pyroptosis and IL-33/ST2 pathways are abnormally activated during the stage of LN. In vivo, similar to the results of the AAV-mediated NLRP3 shRNA MRL/lpr model, HNK downregulated serum and renal IL-33 levels, and suppressed NLRP3 inflammasome and the IL-33/ST2 axis in the kidney. In vitro, co-culturing NLRP3-overexpressing or IL-33 knocked-down rat renal macrophages with NRK-52E cells confirmed that NLRP3 activation in resident macrophages directly upregulates IL-33, which in turn mediates the IL-33/ST2/NF-κB pathway to promote the inflammatory response of renal tubular epithelial cells. Furthermore, a molecular docking model and surface plasmon resonance analysis were utilized to demonstrate a direct interaction between HNK and NLRP3. In conclusion, this study provides a novel anti-LN treatment strategy in which HNK plays a preventive and therapeutic role against LN by suppressing the abnormal crosstalk between renal resident macrophages and renal tubular epithelial cells by inhibiting the activation of the NLRP3/IL-33/ST2 axis.
Subject(s)
Lupus Nephritis , Mice , Animals , Rats , Mice, Inbred MRL lpr , Interleukin-33 , Interleukin-1 Receptor-Like 1 Protein , NLR Family, Pyrin Domain-Containing 3 Protein , Inflammasomes , Molecular Docking Simulation , Kidney , Epithelial Cells , Macrophages , Receptors, Interleukin-1ABSTRACT
Ku70 protein and topoisomerase IIα (Topo IIα) are promising targets of anticancer drugs, which play critical roles in DNA repair and replication processes. Three platinum(II) complexes, [PtCl(NH3)2(9-(pyridin-2-ylmethyl)-9H-carbazole)]NO3 (OPPC), [PtCl(NH3)2(9-(pyridin-3-ylmethyl)-9H-carbazole)]NO3 (MPPC), and [PtCl(NH3)2(9-(pyridin-4-ylmethyl)-9H-carbazole)]NO3 (PPPC), were designed as inhibitors of Ku70 and Topo IIα. Their antitumor activity and inhibitory efficacy on Ku70 and Topo IIα were investigated on cellular and molecular levels. OPPC exhibited high antiproliferative activity against various cancer cell lines, with acute toxicity to mice being lower than that of cisplatin. Moreover, OPPC could enter cancer cells effectively and cause DNA damage, which was evidenced by the enhanced expression of γ-H2AX, Chk1/2 phosphorylation, p53 and cell cycle arrest. OPPC also downregulated the DNA damage repair protein Ku70 and inhibited the formation of Ku70 foci-the central points or loci of Ku70, which would suppress DNA repair and induce a nonhomologous end joining response in cancer cells. More importantly, these complexes showed inhibition towards Topo IIα; in particular, OPPC was more effective than MPPC and PPPC. In the Topo IIα knockdown cells, Ku70 and Topo IIα were directly associated with the DNA damage and apoptotic response. The molecular docking provided detailed structural insights into the interactions of the complexes with Topo IIα. This study demonstrates that the cytotoxicity of these complexes is associated with the DNA damage and repair pathways mediated by Ku70 and Topo IIα; OPPC is an effective inhibitor of Ku70 and Topo IIα and restrains cancer cells via a mechanism utterly distinct from that of cisplatin.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Ku Autoantigen/antagonists & inhibitors , Platinum Compounds/chemical synthesis , Platinum Compounds/pharmacology , Poly-ADP-Ribose Binding Proteins/antagonists & inhibitors , Cell Line, Tumor , DNA Topoisomerases, Type II , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Molecular Structure , Platinum Compounds/chemistryABSTRACT
A new velocity probe which permits recording the time history of detonation and shock waves has been developed by improving the commercial on principle and structure. A method based on the probe is then designed to measure the detonation velocity and near-field shock parameters in a single underwater explosion, by which the oblique shock wave front of cylindrical charges and the peak pressure attenuation curve of spherical explosive are obtained. A further derivation of detonation pressure, adiabatic exponent, and other shock parameters is conducted. The present method offers a novel and reliable parameter determination for near-field underwater explosion.
