Xenon blunts NF-κB/NLRP3 inflammasome activation and improves acute onset of accelerated and severe lupus nephritis in mice

NLRP3 inflammasome and its role in autoimmune diseases: A promising therapeutic target

The NOD-like receptor protein 3 (NLRP3) inflammasome is a protein complex that regulates innate immune responses by activating caspase-1 and the inflammatory cytokines IL-1β and IL-18. Numerous studies have highlighted its crucial role in the pathogenesis and development of inflammatory bowel disease, rheumatoid arthritis, systemic lupus erythematosus, autoimmune thyroid diseases, and other autoimmune diseases. Therefore, investigating the underlying mechanisms of NLRP3 in disease and targeted drug therapies holds clinical significance. This review summarizes the structure, assembly, and activation mechanisms of the NLRP3 inflammasome, focusing on its role and involvement in various autoimmune diseases. This review also identifies studies where the involvement of the NLRP3 inflammasome in the disease mechanism within the same disease appears contradictory, as well as differences in NLRP3-related gene polymorphisms among different ethnic groups. Additionally, the latest therapeutic advances in targeting the NLRP3 inflammasome for autoimmune diseases are outlined, and novel clinical perspectives are discussed. Conclusively, this review provides a consolidated source of information on the NLRP3 inflammasome and may guide future research efforts that have the potential to positively impact patient outcomes.

Identification of monocyte-associated biomarkers in systemic lupus erythematosus and their pan-cancer analysis

Immune dysregulation is not only a pathogenic mechanism in systemic lupus erythematosus (SLE) but also a potential cause of the link between SLE and cancer. The current understanding of SLE monocyte-associated biomarkers is limited, and the precise mechanism behind the link between SLE and cancer is uncertain. By using WGCNA and immune infiltration to analyze the GSE72326 dataset, we determined the most pertinent modules for monocytes and discovered eight candidate hub genes from them. The limma software was used to find genes that were differently expressed in SLE. The genes that overlapped between the two were chosen using a Venn diagram as the essential genes related to monocytes in SLE, and the essential genes were verified by several datasets. Correlation analysis and GSEA analysis were used to examine the probable immunological pathways connected to key genes. We examined the expression of hub genes in cancer and their interaction with monocytes using the GEPIA and TIMER databases to understand the significance of essential genes in tumorigenesis. In addition, we performed transcription factor identification. We discovered three biomarkers (IFI30, BLVRA, and RIN2) that are mostly involved in interferon-related signaling pathways and are associated with monocyte-mediated immune responses in SLE. The three important genes are also strongly expressed in a number of malignancies and have a relationship with monocytes. As a result, IFI30, BLVRA, and RIN2 may act as SLE-associated biomarkers of monocytes and as a bridge between SLE and tumors. We proposed that interferon-related signaling pathways might function as possible mediators of cancer risk in SLE.

Injury Site Specific Xenon Delivered by Platelet Membrane-Mimicking Hybrid Microbubbles to Protect Against Acute Kidney Injury via Inhibition of Cellular Senescence

Inhalation of xenon gas improves acute kidney injury (AKI). However, xenon can only be delivered through inhalation, which causes non-specific distribution and low bioavailability of xenon, thus limiting its clinical application. In this study, xenon is loaded into platelet membrane-mimicking hybrid microbubbles (Xe-Pla-MBs). In ischemia-reperfusion-induced AKI, intravenously injected Xe-Pla-MBs adhere to the endothelial injury site in the kidney. Xe-Pla-MBs are then disrupted by ultrasound, and xenon is released to the injured site. This release of xenon reduced ischemia-reperfusion-induced renal fibrosis and improved renal function, which are associated with decreased protein expression of cellular senescence markers p53 and p16, as well as reduced beta-galactosidase in renal tubular epithelial cells. Together, platelet membrane-mimicking hybrid microbubble-delivered xenon to the injred site protects against ischemia-reperfusion-induced AKI, which likely reduces renal senescence. Thus, the delivery of xenon by platelet membrane-mimicking hybrid microbubbles is a potential therapeutic approach for AKI.

Lipidome modulation by dietary omega-3 polyunsaturated fatty acid supplementation or selective soluble epoxide hydrolase inhibition suppresses rough LPS-accelerated glomerulonephritis in lupus-prone mice

Introduction

Lipopolysaccharide (LPS)-accelerated autoimmune glomerulonephritis (GN) in NZBWF1 mice is a preclinical model potentially applicable for investigating lipidome-modulating interventions against lupus. LPS can be expressed as one of two chemotypes: smooth LPS (S-LPS) or rough LPS (R-LPS) which is devoid of O-antigen polysaccharide sidechain. Since these chemotypes differentially affect toll-like receptor 4 (TLR4)-mediated immune cell responses, these differences may influence GN induction.

Methods

We initially compared the effects of subchronic intraperitoneal (i.p.) injection for 5 wk with 1) Salmonella S-LPS, 2) Salmonella R-LPS, or 3) saline vehicle (VEH) (Study 1) in female NZBWF1 mice. Based on the efficacy of R-LPS in inducing GN, we next used it to compare the impact of two lipidome-modulating interventions, ω-3 polyunsaturated fatty acid (PUFA) supplementation and soluble epoxide hydrolase (sEH) inhibition, on GN (Study 2). Specifically, effects of consuming ω-3 docosahexaenoic acid (DHA) (10 g/kg diet) and/or the sEH inhibitor 1-(4-trifluoro-methoxy-phenyl)-3-(1-propionylpiperidin-4-yl) urea (TPPU) (22.5 mg/kg diet ≈ 3 mg/kg/day) on R-LPS triggering were compared.

Results

In Study 1, R-LPS induced robust elevations in blood urea nitrogen, proteinuria, and hematuria that were not evident in VEH- or S-LPS-treated mice. R-LPS-treated mice further exhibited kidney histopathology including robust hypertrophy, hyperplasia, thickened membranes, lymphocytic accumulation containing B and T cells, and glomerular IgG deposition consistent with GN that was not evident in VEH- or SLPS-treated groups. R-LPS but not S-LPS induced spleen enlargement with lymphoid hyperplasia and inflammatory cell recruitment in the liver. In Study 2, resultant blood fatty acid profiles and epoxy fatty acid concentrations reflected the anticipated DHA- and TPPU-mediated lipidome changes, respectively. The relative rank order of R-LPS-induced GN severity among groups fed experimental diets based on proteinuria, hematuria, histopathologic scoring, and glomerular IgG deposition was: VEH/CON< R-LPS/DHA ≈ R-LPS/TPPU<<< R-LPS/TPPU+DHA ≈ R-LPS/CON. In contrast, these interventions had modest-to- negligible effects on R-LPS-induced splenomegaly, plasma antibody responses, liver inflammation, and inflammation-associated kidney gene expression.

Discussion

We show for the first time that absence of O-antigenic polysaccharide in R-LPS is critical to accelerated GN in lupus-prone mice. Furthermore, intervention by lipidome modulation through DHA feeding or sEH inhibition suppressed R-LPS-induced GN; however, these ameliorative effects were greatly diminished upon combining the treatments.

Pretreatment of the ROS Inhibitor Phenyl-N-tert-butylnitrone Alleviates Sleep Deprivation-Induced Hyperalgesia by Suppressing Microglia Activation and NLRP3 Inflammasome Activity in the Spinal Dorsal Cord

Sleep deprivation, a common perioperative period health problem, causes ocular discomfort and affects postsurgical pain. However, the mechanism of sleep deprivation-induced increased pain sensitivity is elusive. This study aims to explore the role of ROS in sleep deprivation (SD)-induced hyperalgesia and the underlying mechanism. A 48-h continuous SD was performed prior to the hind paw incision pain modeling in mice. We measured ROS levels, microglial activation, DNA damage and protein levels of iNOS, NLRP3, p-P65 and P65 in mouse spinal dorsal cord. The involvement of ROS in SD-induced prolongation of postsurgical pain was further confirmed by intrathecal injection of ROS inhibitor, phenyl-N-tert-butylnitrone (PBN). Pretreatment of 48-h SD in mice significantly prolonged postsurgical pain recovery, manifesting as lowered paw withdrawal mechanical threshold and paw withdrawal thermal latency. It caused ROS increase and upregulation of iNOS on both Day 1 and 7 in mouse spinal dorsal cord. In addition, upregulation of NLRP3 and p-P65, microglial activation and DNA damage were observed in mice pretreated with 48-h SD prior to the incision. Notably, intrathecal injection of PBN significantly reversed the harmful effects of SD on postsurgical pain recovery, hyperalgesia, microglial activation and DNA damage via the NF-κB signaling pathway. Collectively, ROS increase is responsible for SD-induced hyperalgesia through activating microglial, triggering DNA damage and enhancing NLRP3 inflammasome activity in the spinal dorsal cord.

Some Beneficial Effects of Inert Gases on Blood Oxidative Metabolism: In Vivo Study

The aim of the study was to assess the effect of external use of inert gases (helium and argon) on the state of free radical processes in vivo. The experiment was performed on 30 male Wistar stock rats (age-3 months, weight-200-220 g.), randomly distributed into 3 equal groups. The first group of animals was intact (n = 10). The animals of the second and third groups were treated with argon and helium streams, respectively. Our research has allowed us to establish that the studied inert gases have a modulating effect on the state of oxidative metabolism of rat blood, and the nature of this effect is directly determined by the type of gas. The results of this study allowed us to establish the potential antioxidant effect of the helium stream, mainly realized due to the activation of the catalytic properties of the enzymatic link of the antioxidant system of rat blood plasma. At the same time, the revealed features of shifts in oxidative metabolism during treatment with argon flow include not only stimulation of the antioxidant system but also the pronounced induction of free radical oxidation. Thus, the conducted studies made it possible to verify the specificity of the response of the oxidative metabolism of blood plasma to the use of inert gases, depending on their type.

Effects of Lactobacillus plantarum HFY15 on Lupus Nephritis in Mice by Regulation of the TGF-β1 Signaling Pathway

Objective

In this study, the Lactobacillus plantarum HFY15 (LP-HFY15) strain isolated from naturally fermented yak yogurt was investigated. An animal model of lupus nephritis was established by pristane to verify the interventional effect of LP-HFY15 on mouse lupus nephritis by regulating the transforming growth factor-β1 (TGF-β1) signaling pathway.

Materials and Methods

Indexes in mouse serum and tissues were detected by kits, pathological changes in mouse kidney were observed by hematoxylin-eosin (H&E) staining, and quantitative polymerase chain reaction (qPCR) was used to detect TGF-β 1-related expression in mouse kidney tissue, which further elucidated the mechanism of LP-HFY15.

Results

LP-HFY15 decreased the elevation of urinary protein and the levels of interleukin-6 (IL-6), IL-12, tumor necrosis factor alpha (TNF-α), and interferon γ (IFN-γ) in serum and kidney tissue. LP-HFY15 also reduced serum creatinine (SCr), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), and raised total protein (TP), and albumin (ALB) levels in mice with nephritis. In addition, LP-HFY15 inhibited the positive rate of double-stranded deoxyribonucleic acid (dsDNA) antibodies in mice with nephritis. The observation of H&E sections showed that LP-HFY15 alleviated the glomerulus morphological incompleteness and inflammatory infiltration caused by nephritis. Further results showed that LP-HFY15 downregulated the mRNA expression of TGF-β1, vascular endothelial growth factor (VEGF), and nuclear factor kappa-B (NF-κB) in the kidneys of lupus nephritis mice, and the expression of inhibitor of NF-κB (IκB-α), copper/zinc superoxide dismutase (Cu/Zn-SOD), and manganese superoxide dismutase (Mn-SOD) was also upregulated.

Conclusion

These results indicated that LP-HFY15 plays a significant role in experimental intervention for lupus nephritis. The effect of LP-HFY15 was positively correlated with its concentration, and the effect was similar to that of prednisone at 10⁹ CFU/kg.

Signaling pathways of chronic kidney diseases, implications for therapeutics

Chronic kidney disease (CKD) is a chronic renal dysfunction syndrome that is characterized by nephron loss, inflammation, myofibroblasts activation, and extracellular matrix (ECM) deposition. Lipotoxicity and oxidative stress are the driving force for the loss of nephron including tubules, glomerulus, and endothelium. NLRP3 inflammasome signaling, MAPK signaling, PI3K/Akt signaling, and RAAS signaling involves in lipotoxicity. The upregulated Nox expression and the decreased Nrf2 expression result in oxidative stress directly. The injured renal resident cells release proinflammatory cytokines and chemokines to recruit immune cells such as macrophages from bone marrow. NF-κB signaling, NLRP3 inflammasome signaling, JAK-STAT signaling, Toll-like receptor signaling, and cGAS-STING signaling are major signaling pathways that mediate inflammation in inflammatory cells including immune cells and injured renal resident cells. The inflammatory cells produce and secret a great number of profibrotic cytokines such as TGF-β1, Wnt ligands, and angiotensin II. TGF-β signaling, Wnt signaling, RAAS signaling, and Notch signaling evoke the activation of myofibroblasts and promote the generation of ECM. The potential therapies targeted to these signaling pathways are also introduced here. In this review, we update the key signaling pathways of lipotoxicity, oxidative stress, inflammation, and myofibroblasts activation in kidneys with chronic injury, and the targeted drugs based on the latest studies. Unifying these pathways and the targeted therapies will be instrumental to advance further basic and clinical investigation in CKD.

Novel insights into NOD-like receptors in renal diseases

Nucleotide-binding oligomerization domain-like receptors (NLRs), including NLRAs, NLRBs (also known as NAIPs), NLRCs, and NLRPs, are a major subfamily of pattern recognition receptors (PRRs). Owing to a recent surge in research, NLRs have gained considerable attention due to their involvement in mediating the innate immune response and perpetuating inflammatory pathways, which is a central phenomenon in the pathogenesis of multiple diseases, including renal diseases. NLRs are expressed in different renal tissues during pathological conditions, which suggest that these receptors play roles in acute kidney injury, obstructive nephropathy, diabetic nephropathy, IgA nephropathy, lupus nephritis, crystal nephropathy, uric acid nephropathy, and renal cell carcinoma, among others. This review summarises recent progress on the functions of NLRs and their mechanisms in the pathophysiological processes of different types of renal diseases to help us better understand the role of NLRs in the kidney and provide a theoretical basis for NLR-targeted therapy for renal diseases.

Noble Gases Therapy in Cardiocerebrovascular Diseases: The Novel Stars?

Cardiocerebrovascular diseases (CCVDs) are the leading cause of death worldwide; therefore, to deeply explore the pathogenesis of CCVDs and to find the cheap and efficient strategies to prevent and treat CCVDs, these are of great clinical and social significance. The discovery of nitric oxide (NO), as one of the endothelium-derived relaxing factors and its successful utilization in clinical practice for CCVDs, provides new ideas for us to develop drugs for CCVDs: “gas medicine” or “medical gases.” The endogenous gas molecules such as carbon monoxide (CO), hydrogen sulfide (H₂S), sulfur dioxide (SO₂), methane (CH₄), and hydrogen (H₂) have essential biological effects on modulating cardiocerebrovascular homeostasis and CCVDs. Moreover, it has been shown that noble gas atoms such as helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe) display strong cytoprotective effects and therefore, act as the exogenous pharmacologic preventive and therapeutic agents for CCVDs. Mechanistically, besides the competitive inhibition of N-methyl-D-aspartate (NMDA) receptor in nervous system by xenon, the key and common mechanisms of noble gases are involved in modulation of cell death and inflammatory or immune signals. Moreover, gases interaction and reduction in oxidative stress are emerging as the novel biological mechanisms of noble gases. Therefore, to investigate the precise actions of noble gases on redox signals, gases interaction, different cell death forms, and the emerging field of gasoimmunology, which focus on the effects of gas atoms/molecules on innate immune signaling or immune cells under both the homeostatic and perturbed conditions, these will help us to uncover the mystery of noble gases in modulating CCVDs.

NLRP3 Inflammasome: Checkpoint Connecting Innate and Adaptive Immunity in Autoimmune Diseases

Autoimmune diseases are a broad spectrum of human diseases that are characterized by the breakdown of immune tolerance and the production of autoantibodies. Recently, dysfunction of innate and adaptive immunity is considered to be a key step in the initiation and maintenance of autoimmune diseases. NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is a multimeric protein complex, which can detect exogenous pathogen irritants and endogenous danger signals. The main function of NLRP3 inflammasome is to promote secretion of interleukin (IL)-1β and IL-18, and pyroptosis mediated by caspase-1. Served as a checkpoint in innate and adaptive immunity, aberrant activation and regulation of NLRP3 inflammasome plays an important role in the pathogenesis of autoimmune diseases. This paper reviewed the roles of NLRP3 inflammasome in autoimmune diseases, which shows NLRP3 inflammasome may be a potential target for autoimmune diseases deserved further study.

Role of vitamin D/VDR nuclear translocation in down-regulation of NF-κB/NLRP3/caspase-1 axis in lupus nephritis

BACKGROUND

Vitamin D receptor (VDR) and NLRP3 inflammasome play critical roles in lupus nephritis (LN) pathogenesis.

AIM OF THE STUDY

This study explored the therapeutic effect of VDR agonist on LN and its molecular mechanism to inhibit NLRP3 signalling.

METHODS

C57BL/6 mice, lupus-prone MRL/lpr mice, and VDR agonist paricacitol-treated MRL/lpr mice (300 ng/kg/mouse per dose, 5 times/week for 8 weeks from 8 weeks old) were used to assess kidney histopathology and measure proteinuria, serum anti-ds-DNA antibody and expression of NF-κB/NLRP3/caspase-1/IL-1β/IL-18 axis. We used mouse renal tubular epithelial cells (mRTECs) to identify protein-protein interactions and examine the effects of paricalcitol.

RESULTS AND CONCLUSION

LN pathogenesis decreased after paricalcitol treatment. We observed a marked improvement in renal pathology and a time-dependent decrease urine protein and serum anti-dsDNA antibody levels. In 16-week-old MRL/lpr LN mice, the upregulated expression of NLRP3/caspase-1/IL-1β/IL-18 axis was significantly downregulated after paricalcitol treatment. Paricalcitol can reverse the apoptosis induced by anti-dsDNA antibody via the NF-κB/NLRP3/caspase-1/IL-1β/IL-18 axis in mRTECs. Furthermore, paricalcitol suppressed NF-κB nuclear translocation by competitively binding to importin-4. In summary, the VDR agonist can alleviate LN by modulating the NF-κB/NLRP3/caspase-1/IL-1β/IL-18 axis and suppressing the NF-κB nuclear translocation.

Role of NLRP3 Inflammasome in Lupus Nephritis and Therapeutic Targeting by Phytochemicals

Systemic lupus erythematosus (SLE) is a multisystem autoimmune inflammatory condition that affects multiple organs and provokes extensive and severe clinical manifestations. Lupus nephritis (LN) is one of the main clinical manifestations of SLE. It refers to the deposition of immune complexes in the glomeruli, which cause kidney inflammation. Although LN seriously affects prognosis and represents a key factor of disability and death in SLE patients, its mechanism remains unclear. The NACHT, leucine-rich repeat (LRR), and pyrin (PYD) domains-containing protein 3 (NLRP3) inflammasome regulates IL-1β and IL-18 secretion and gasdermin D-mediated pyroptosis and plays a key role in innate immunity. There is increasing evidence that aberrant activation of the NLRP3 inflammasome and downstream inflammatory pathways play an important part in the pathogenesis of multiple autoimmune diseases, including LN. This review summarizes research progress on the elucidation of NLRP3 activation, regulation, and recent clinical trials and experimental studies implicating the NLRP3 inflammasome in the pathophysiology of LN. Current treatments fail to provide durable remission and provoke several sides effects, mainly due to their broad immunosuppressive effects. Therefore, the identification of a safe and effective therapeutic approach for LN is of great significance. Phytochemicals are found in many herbs, fruits, and vegetables and are secondary metabolites of plants. Evidence suggests that phytochemicals have broad biological activities and have good prospects in a variety of diseases, including LN. Therefore, this review reports on current research evaluating phytochemicals for targeting NLRP3 inflammasome pathways in LN therapy.

DNMT3B decreases extracellular matrix degradation and alleviates intervertebral disc degeneration through TRPA1 methylation to inhibit the COX2/YAP axis

Intervertebral disc degeneration (IVDD) is a main cause of low back pain that is associated with extracellular matrix (ECM) degradation and inflammation. This study aims to investigate the role of DNMT3B and its regulatory mechanisms in IVDD. IVDD rat models were constructed followed by transfections with oe-DNMT3B or oe-YAP in order to explore the role of DNMT3B in the development of IVDD. After that transfection, nucleus pulposus (NP) cells were isolated and transfected with oe-DNMT3B, oe-TRPA1, si-YAP, oe-YAP or oe-COX2 in order to investigate the functions of DNMT3B in NP cells. DNMT3B was poorly expressed in IVDD tissues and NP cells whereas TRPA1, COX2, and YAP were highly expressed. The proliferation or apoptosis of NP cells was detected through CCK-8 assay or flow cytometry, respectively. Overexpression of DNMT3B promoted the proliferation of NP cells, inhibited their apoptosis, as well as increasing the expression of collagen II and aggrecan and decreasing expression of MMP3 and MMP9. Besides, DNMT3B suppressed inflammation and alleviated IVDD. Mechanistically, DNMT3B modified the TRPA1 promoter by methylation to inhibit the expression of COX2. Overexpression of COX2 promoted the apoptosis of NP cells and decreased the expression of YAP, which was reversed by upregulating DNMT3B. DNMT3B may promote the proliferation of NP cells and prevent their ECM degradation through the TRPA1/COX2/YAP axis, thereby alleviating IVDD in rats.

Cf-02, a novel benzamide-linked small molecule, blunts NF-κB activation and NLRP3 inflammasome assembly and improves acute onset of accelerated and severe lupus nephritis in mice

In the present study, acute onset of severe lupus nephritis was successfully treated in mice using a new, benzamide-linked, small molecule that targets immune modulation and the NLRP3 inflammasome. Specifically, 6-(2,4-difluorophenyl)-3-(3-(trifluoromethyl)phenyl)-2H-benzo[e][1,3]oxazine-2,4(3H)-dione (Cf-02) (a) reduced serum levels of IgG anti-dsDNA, IL-1β, IL-6, and TNF-α, (b) inhibited activation of dendritic cells and differentially regulated T cell functions, and (c) suppressed the NF-κB/NLRP3 inflammasome axis, targeting priming and activating signals of the inflammasome. Moreover, treatment with Cf-02 significantly inhibited secretion of IL-1β in lipopolysaccharide-stimulated macrophages, but this effect was abolished by autophagy induction. These results recommend Cf-02 as a promising drug candidate for the serious renal conditions associated with systemic lupus erythematosus. Future investigations should examine whether Cf-02 may also be therapeutic in other types of chronic kidney disease involving NLRP3 inflammasome-driven signaling.

The occurrence of lupus nephritis is regulated by USP7-mediated JMJD3 stabilization

Ubiquitin-specific peptidases7 (USP7) participates in the regulation of various metabolic and immune disorders. However, the role of USP7 in lupus nephritis (LN) remains unknown. The current study set out to elucidate the regulatory role of USP7 in LN together with JMJD3 and NF-κB. SLE MRL/LPR mice and mouse glomerular mesangial cells SV40 MES 13 cells were employed for in vivo or vitro experiments. USP7, JMJD3 and NF-κB expression in MRL/LPR mice were detected, followed by investigation of their functions in the proliferation of mesangial cells and mesangial matrix. Subsequently, the interaction among USP7, JMJD3 and NF-κB was determined by means of ChIP and co-immunoprecipitation assay. The results indicated that USP7, JMJD3, p-NF-κB p65 were all highly-expressed in MRL/LPR mice. USP7 promoted the proliferation of mesangial cells and mesangial matrix, and stabilized the JMJD3 protein via deubiquitination in SV40 MES 13 cells. Meanwhile, silencing of JMJD3 inhibited the promotive effect of USP7 on the proliferation of mesangial cells and mesangial matrix. Furthermore, JMJD3 increased the expression of NF-κB p65 through demethylation, whereas silencing JMJD3 alleviated the proliferation of mesangial cells and mesangial matrix. Lastly, NF-κB p65 was proved to aggravate LN pathogenesis. Altogether, our findings highlighted that USP7 promoted the occurrence of LN by regulating the NF-κB p65 signaling pathway via stabilization of JMJD3.

Oxidative stress-induced aberrant lipid metabolism is an important causal factor for dysfunction of immunocytes from patients with systemic lupus erythematosus

There exist close relationships among oxidative stress, dyslipidaemia, inflammation, and autoimmune response in patients with systemic lupus erythematosus (SLE). Dysfunction and/or dysregulation of immunocytes is one of the major characteristics of SLE pathogenesis. Lipids play many important roles in biological processes and cellular functions. We hypothesized that oxidative stress-induced aberrant lipid metabolism and integrity presented in immunocytes is one of the early events in patients, thereby leading to enhanced production of IgG autoantibodies and cytokines. Herein, shotgun lipidomics was employed for quantitative analysis of cellular lipidomes in peripheral blood mononuclear cells (PBMC) both freshly isolated from SLE patients and cultured with treatment. The levels of IgG autoantibodies and cytokines in cell culture media and serum samples from lupus-prone mice treated with a natural, powerful antioxidant isotonix OPC-3 were measured by ELISA kits. IgG antibody deposition in glomeruli of the mice was determined by immunofluorescence analysis. Lipidomics analysis of PBMC from 33 SLE patients and 28 healthy controls revealed aberrant lipid metabolism in PBMC from the patients. The changes included significantly reduced plasmalogens, markedly increased lysophospholipids, altered phosphatidylserines, and accumulated 4-hydroxyalkenals. These alterations of lipids in SLE PBMC could be significantly corrected after cultured with the antioxidant in vitro. Parallel to the IgG antibody deposition in glomeruli, the concentrations of cytokines (i.e., IL-10, IL-6, and TNF-α) and autoantibodies (e.g., IgG antiphospholipid and anti-dsDNA antibodies) in culture medium and serum samples from the mice after treatment with the antioxidant were also significantly reduced compared with those of the SLE group. The results clearly demonstrated that correction of the aberrant lipid metabolism led to inhibition of the autoimmune reactions of PBMC after reduction of the increased oxidative stress. The current study also revealed potential drug treatment of SLE with lesser adverse effects through reducing the aberrant lipid metabolism with an effective antioxidant.

Accelerated, severe lupus nephritis benefits from treatment with honokiol by immunoregulation and differentially regulating NF-κB/NLRP3 inflammasome and sirtuin 1/autophagy axis

Using honokiol (HNK), a major anti-inflammatory bioactive compound in Magnolia officinalis, we show a potent therapeutic outcome against an accelerated, severe form of lupus nephritis (ASLN). The latter may follow infectious insults that act as environmental triggers in the patients. In the current study, an ASLN model in NZB/W F1 mice was treated with HNK by daily gavage after onset of the disease. We show that HNK ameliorated the ASLN by improving renal function, albuminuria, and renal pathology, especially reducing cellular crescents, neutrophil influx, fibrinoid necrosis in glomeruli, and glomerulonephritis activity scores. Meanwhile, HNK differentially regulated T cell functions, reduced serum anti-dsDNA autoantibodies, and inhibited NLRP3 inflammasome activation in the mice. The latter involved: (a) suppressed production of reactive oxygen species and NF-κB activation-mediated priming signal of the inflammasome, (b) reduced mitochondrial damage, and (c) enhanced sirtuin 1 (SIRT1)/autophagy axis activation. In conclusion, HNK represents a new drug candidate for acute, severe episodes of LN capable of alleviating renal lesions in ASLN mice by negatively regulating T cell functions and by enhancing SIRT1/autophagy axis-lessened NLRP3 inflammasome activation.