Astragalus propinquus Schischkin and Panax notoginseng (A&P) compound relieved cisplatin-induced acute kidney injury through inhibiting the mincle maintained macrophage inflammation

Curcumin relieved cisplatin-induced kidney inflammation through inhibiting Mincle-maintained M1 macrophage phenotype

Acute kidney injury (AKI) with high incidence and mortality is the main cause of chronic kidney disease. Previous studies have indicated that quercetin, an abundant flavonoid in plants, exhibited renoprotective role in AKI. However, the underlying mechanism is largely unknown. In this study, we try to explore whether quercetin protects against AKI by inhibiting macrophage inflammation via regulation of Mincle/Syk/NF-κB signaling. The results demonstrated that quercetin can significantly inhibit expression and secretion of IL-1β, IL-6, and TNF-α in LPS-induced bone marrow-derived macrophages (BMDMs) and reduce activity of Mincle/Syk/NF-κB signaling in vitro. We also found that quercetin can strongly reduce the concentration of serum creatinine, BUN, IL-1β, IL-6, and TNF-α in cisplatin-induced AKI model. Furthermore, quercetin down-regulated protein levels of Mincle, phosphorylated Syk and NF-κB in kidney macrophages of AKI, as well as inhibited M1, up-regulated M2 macrophage activity. Notably, the down-regulation of LPS-induced inflammation by quercetin was reversed after adding TDB (an agonist of Mincle) in BMDMs, suggesting that quercetin suppresses macrophage inflammation may mainly through inhibiting Mincle and its downstream signaling. In summary, these findings clarified a new mechanism of quercetin improving AKI-induced kidney inflammation and injury, which provides a new drug option for the clinical treatment of AKI.

BackgroundDiabetic nephropathy (DN) is one of the main causes of end-stage renal disease with scantly effective treatment. Numerous evidences indicated that macrophages play an important role in the occurrence and pathogenesis of DN by secreting inflammatory cytokines. Mincle is mainly expressed in macrophages and promotes kidney inflammation and damage of acute kidney injury. However, the role of Mincle in DN is unclear. In this study, we aim to investigate the effect of Mincle-related macrophage inflammation on DN, and whether it can be identified as the therapeutic target for Astragalus mongholicus Bunge and Panax notoginseng Formula (A&P), a widely used Chinese herbal decoction for DN treatment.MethodsIn vivo experiments high-fat and high-sugar diet and streptozotocin was used to establish a diabetic nephropathy model, while in vitro experiments inflammation model was induced by high-glucose in mouse Bone Marrow-Derived Macrophages (BMDM) cells and mouse mesangial (MES) cells. Kidney pathological staining is used to detect kidney tissue damage and inflammation, Western blotting, Real-time PCR and ELISA are performed to detect Mincle signaling pathway related proteins and inflammatory cytokines.ResultsMincle was mainly expressed in infiltrated macrophage of DN kidney, and was significant decreased after A&P administration. The in vitro experiments also proved that A&P effectively down-regulated the expression of Mincle in macrophage stimulated by high glucose. Meanwhile, the data demonstrated that A&P can reduce the activation of NFκB, and the expression and secretion of inflammatory cytokines in DN kidney or BMDM cells. Notably, we set up a co-culture system to conform that BMDM cells can aggravate the inflammatory response of mesangial (MES) cells under high glucose stimulation. Furthermore, we found that the anti-injury role of A&P in MES cells was dependent on inhibition of the Mincle in macrophage.ConclusionIn summary, our study found that A&P is effective in reducing renal pathological damage and improving renal function and inflammation in diabetic nephropathy by a mechanism mainly related to the inhibition of the Mincle/Card9/NFκB signaling pathway.

Acute kidney injury (AKI) is a highly prevalent clinical syndrome with high mortality and morbidity. Previous studies indicated that inflammation promotes tubular damage and plays a key role in AKI progress. Spleen tyrosine kinase (Syk) has been linked to macrophage-related inflammation in AKI. Up to date, however, no Syk-targeted therapy for AKI has been reported. In this study, we employed both cell model of LPS-induced bone marrow-derived macrophage (BMDM) and mouse model of ischemia/reperfusion injury (IRI)-induced AKI to evaluate the effects of a Syk inhibitor, BAY61-3606 (BAY), on macrophage inflammation in vitro and protection of kidney from AKI in vivo. The expression and secretion of inflammatory cytokines, both in vitro and in vivo, were significantly inhibited even back to normal levels by BAY. The upregulated serum creatinine and blood urea nitrogen levels in the AKI mice were significantly reduced after administration of BAY, implicating a protective effect of BAY on kidneys against IRI. Further analyses from Western blot, immunofluorescence staining and flow cytometry revealed that BAY inhibited the Mincle/Syk/NF-κB signaling circuit and reduced the inflammatory response. BAY also inhibited the reactive oxygen species (ROS), which further decreased the formation of inflammasome and suppressed the mature of IL-1β and IL-18. Notably, these inhibitory effects of BAY on inflammation and inflammasome in BMDM were significantly reversed by Mincle ligand, trehalose-6,6-dibehenate. In summary, these findings provided compelling evidence that BAY may be an efficient inhibitor of the Mincle/Syk/NF-κB signaling circuit and ROS-induced inflammasome, which may help to develop Syk-inhibitors as novel therapeutic agents for AKI.

Macrophages play critical roles in inflammation and tissue homeostasis, and their functions are regulated by various autocrine, paracrine, and endocrine factors. We have previously shown that CTRP6, a secreted protein of the C1q family, targets both adipocytes and macrophages to promote obesity-linked inflammation. However, the gene programs and signaling pathways directly regulated by CTRP6 in macrophages remain unknown. Here, we combine transcriptomic and phosphoproteomic analyses to show that CTRP6 activates inflammatory gene programs and signaling pathways in mouse bone marrow-derived macrophages (BMDMs). Treatment of BMDMs with CTRP6 upregulated proinflammatory, and suppressed the antiinflammatory, gene expression. We also showed that CTRP6 activates p44/42-MAPK, p38-MAPK, and NF-κB signaling pathways to promote inflammatory cytokine secretion from BMDMs, and that pharmacologic inhibition of these signaling pathways markedly attenuated the effects of CTRP6. Pretreatment of BMDMs with CTRP6 also sensitized and potentiated the BMDMs response to lipopolysaccharide (LPS)-induced inflammatory signaling and cytokine secretion. Consistent with the metabolic phenotype of proinflammatory macrophages, CTRP6 treatment induced a shift toward aerobic glycolysis and lactate production, reduced oxidative metabolism, and elevated mitochondrial reactive oxygen species production in BMDMs. Importantly, in accordance with our in vitro findings, BMDMs from CTRP6-deficient mice were less inflammatory at baseline and showed a marked suppression of LPS-induced inflammatory gene expression and cytokine secretion. Finally, loss of CTRP6 in mice also dampened LPS-induced inflammation and hypothermia. Collectively, our findings suggest that CTRP6 regulates and primes the macrophage response to inflammatory stimuli and thus may have a role in modulating tissue inflammatory tone in different physiological and disease contexts.

BackgroundFisetin, a natural potent flavonoid, has various beneficial, pharmacological activities. In this study, we investigated expression changes of the fisetin regulating genes in lipopolysaccharide (LPS)-treated RAW264.7 cells and explored the role of fisetin in inflammation and autophagy.Methods and resultsMicroarray analysis identified 1,071 genes that were regulated by fisetin in LPS-treated RAW264.7 cells, and these genes were mainly related to the process of immune system response. Quantitative real-time polymerase chain reaction and Bio-Plex analysis indicated that fisetin decreased the expression and secretion of several inflammatory cytokines in cells administered with LPS. Western blot analysis and immunofluorescence assay showed that fisetin decreased microtubule-associated protein 1 light-chain 3B (LC3B) and lysosome-associated membrane protein 1 (LAMP1) expression in LPS-treated cells, while the autophagy inhibitor chloroquine (CQ) could partially reverse this effect. In addition, fisetin reduced the elevated expression of p-PI3K, p-AKT and p-mTOR induced by LPS in a concentration-dependent manner.ConclusionsFisetin diminished the expression and secretion of inflammatory cytokines and facilitated autophagosome-lysosome fusion and degradation in LPS-treated RAW264.7 cells via inhibition of the PI3K/AKT/mTOR signaling pathway. Overall, the results of this study provide new clues for the anti-inflammatory mechanism of fisetin and explain the crosstalk between autophagy and inflammation to some extent.

Autophagy is a key regulator of cellular homeostasis that can be activated by pathogen-associated molecules and recently has been shown to influence IL-1β secretion by macrophages. However, the mechanisms behind this are unclear. Here, we describe a novel role for autophagy in regulating the production of IL-1β in antigen-presenting cells. After treatment of macrophages with Toll-like receptor ligands, pro-IL-1β was specifically sequestered into autophagosomes, whereas further activation of autophagy with rapamycin induced the degradation of pro-IL-1β and blocked secretion of the mature cytokine. Inhibition of autophagy promoted the processing and secretion of IL-1β by antigen-presenting cells in an NLRP3- and TRIF-dependent manner. This effect was reduced by inhibition of reactive oxygen species but was independent of NOX2. Induction of autophagy in mice in vivo with rapamycin reduced serum levels of IL-1β in response to challenge with LPS. These data demonstrate that autophagy controls the production of IL-1β through at least two separate mechanisms: by targeting pro-IL-1β for lysosomal degradation and by regulating activation of the NLRP3 inflammasome.

Viruses and hosts have coevolved for millions of years, leading to the development of complex host–pathogen interactions. Influenza A virus (IAV) causes severe pulmonary pathology and is a recurrent threat to human health. Innate immune sensing of IAV triggers a complex chain of host responses. IAV has adapted to evade host defense mechanisms, and the host has coevolved to counteract these evasion strategies. However, the molecular mechanisms governing the balance between host defense and viral immune evasion is poorly understood. Here, we show that the host protein DEAD-box helicase 3 X-linked (DDX3X) is critical to orchestrate a multifaceted antiviral innate response during IAV infection, coordinating the activation of the nucleotide-binding oligomerization domain-like receptor with a pyrin domain 3 (NLRP3) inflammasome, assembly of stress granules, and type I interferon (IFN) responses. DDX3X activated the NLRP3 inflammasome in response to WT IAV, which carries the immune evasive nonstructural protein 1 (NS1). However, in the absence of NS1, DDX3X promoted the formation of stress granules that facilitated efficient activation of type I IFN signaling. Moreover, induction of DDX3X-containing stress granules by external stimuli after IAV infection led to increased type I IFN signaling, suggesting that NS1 actively inhibits stress granule–mediated host responses and DDX3X-mediated NLRP3 activation counteracts this action. Furthermore, the loss of DDX3X expression in myeloid cells caused severe pulmonary pathogenesis and morbidity in IAV-infected mice. Together, our findings show that DDX3X orchestrates alternate modes of innate host defense which are critical to fight against NS1-mediated immune evasion strategies during IAV infection.

P145 HCQ alleviates 5-FU-induced intestinal inflammation through inhibiting TLR9-dependent DNA sensing pathway

Atherosclerosis is often described as an inflammatory disease of the arteries. One mechanism whereby apolipoprotein A-I (apoA-I) exerts its anti-atherosclerotic effect is by mitigating the inflammatory response of cells involved in atherosclerosis progression. However, oxidation transforms apoA-I from an anti-inflammatory to a pro-inflammatory protein. We previously reported that oxidation can also promote apoA-I aggregation and formation of amyloid fibrils. In this study, we investigated the mechanistic interplay between oxidation, amyloid formation and the inflammatory response of macrophages to apoA-I. We hypothesized that amyloid fibrils constituted of oxidized apoA-I activate production of inflammatory cytokines in macrophages. To test this hypothesis, amyloidogenic apoA-I was generated by oxidation with an excess of H 2 O 2 (H 2 O 2 -ApoA-I). Intracellular and secreted levels of IL-1β were determined upon incubation of mouse bone marrow derived macrophages (BMDM) with intact-apoA-I, soluble H 2 O 2 -ApoA-I and pre-formed H 2 O 2 -ApoA-I amyloid fibrils. Cellular cholesterol release from RAW264.7 cells was also measured. Soluble H 2 O 2 -ApoA-I (amyloid precursor) retained the cellular cholesterol release capacity of intact-ApoA-I. In BMDM incubated with soluble H 2 O 2 -ApoA-I however, levels of IL-1β synthesis and secretion were at least 2-fold higher than those induced by intact-ApoA-I. In contrast, incubation with H 2 O 2 -ApoA-I amyloid fibrils did not increase the levels of IL-1β synthesis and secretion, compared to intact-ApoA-I. Thus, soluble and functional oxidized apoA-I activates inflammatory cytokine synthesis and secretion in macrophages. Notably, this pro-inflammatory potential was completely neutralized when oxidized apoA-I was aggregated in amyloids. Therefore in atherosclerotic lesions, amyloid formation could reduce, rather than exacerbate, the inflammatory burden produced by pro-inflammatory soluble oxidized apoA-I species.

Objective To observe the effects of berberine (BBR) on expression of inflammatory cytokines in THP-1 cells induced by lipopolysaccharide (LPS),and investigate the anti-inflammatory effects of BBR.Methods For analysing the toxicity of BBR on THP-1 cells,THP-1 cells were divided into control group,and different concentrations of BBR groups (BBR 5,10,20,50 μmol/L).After incubation for 6,24 and 48 hours,lactate dehydrogenase (LDH) released from THP-1 cells was used to assay the cytotoxicity of BBR.For analysis of the effects of BBR on inflammatory cytokines induced by LPS in THP-1 cells,THP-1 cells were divided into control group,LPS group (1 μg/mL LPS),and different concentrations of BBR with LPS groups (BBR 5,10 and 20 μmol/L + 1 μg/mL LPS).After 6,24 or 48 hours of incubation,the concentrations of inter4eukin (IL)-1 β,IL-6,IL-8 and tumor necrosis factor(TNF)-α in the culture medium were measured by enzyme-linked immunosorbent assay (ELISA).Results The survival rates of THP-1 cells were all over 90％after treated with BBR lower than 20 μmol/L for 6,24 and 48 hours.BBR decreased the release of IL-1β,IL-6,IL-8 and TNF-α from THP-1 cells in a dose-dependent manner.After 6 hours,20 μmol/L of BBR decreased the secretion of IL-1 β,IL-8 and TNF-α significantly compared with LPS group (P ＜ 0.05).After 24 hours,the secretion of IL-8 and TNF-α was decreased significantly in 20 μmol/L of BBR + LPS group compared with those in LPS group (P ＜ 0.05).After 48 hours,the secretion of TNF-α was decreased signifi-cantly (F=92.625,P ＜ 0.05) in 5 μmol/L BBR + LPS group,the secrection of IL-1β、IL-6 and TNF-α were decreased (all P ＜ 0.05) in 10 μmol/L BBR + LPS group,and the secretion of IL-1β,IL-6 and TNF-α were decreased in 20 μmol/L BBR + LPS group compared with those in LPS group (all P ＜ 0.05).Conclusion BBR can decrease the secretion of inflammatory cytokines in THP-1 cells induced by LPS in a dose-dependent manner. Key words: Berberine; THP-1 cells; Lipopolysaccharide; Inflammatory cytokines

Macrophages play an important role in mediating inflammation in numerous disease states by secreting pro-inflammatory cytokines including IL-1β and IL-18. Macrophages are driven into the M1-proinflammatory phenotype upon detection of pathogen-associated molecular patterns (PAMPs), or damage-associated molecular patterns (DAMPs). As macrophages are polarized into the M1 phenotype, they upregulate the expression of pro-inflammatory cytokines and components of the NLRP3 inflammasome. An additional activating stimulus is required to induce the assembly of the NLRP3 inflammasome, which facilitates the activation of pro-caspase 1 and the subsequent conversion of the pro-forms of both IL-18 and IL-1β into their mature forms for their secretion through gasdermin D membrane pores. A canonical activator of the NLRP3 inflammasome is extracellular ATP. ATP activation of the P2X7 receptor induces potassium efflux and calcium influx, both of which are necessary for NLRP3 inflammasome activation. Previous studies suggest that the G protein-coupled receptor (GPER) agonist G-1 reduced inflammation in animal disease models. However, the GPER-dependent effect of G-1 on pro-inflammatory cytokine expression and NLRP3 inflammasome activation in macrophages is unknown. In the current study, we utilized bone marrow-derived macrophages (BMDMs) from either WT or GPER-/- mice to test the hypothesis that G-1 reduces inflammatory cytokine production and NLRP3 inflammasome expression in a GPER-dependent manner. We found that the treatment of WT BMDMs with 100 nM G-1 for 24 hrs inhibited LPS-induced NLRP3, pro-IL-1β, IL-6, CCL5 and expression, and IL-1β secretion. Importantly, G-1 had no effect on GPER-/- BMDMs. To begin to determine if GPER modulates NLRP3 inflammasome activation, we characterized ATP-induced Ca2+ signals in both WT and GPER BMDMs with and without LPS pretreatment. No differences were observed between unprimed WT and GPER-/- BMDMs with respect to basal Ca2+ level, ATP-induced intracellular Ca2+ release, and subsequent bulk Ca2+ signal upon reestablishment of extracellular Ca2+. However, priming with LPS significantly increased ATP-induced intracellular Ca2+ release in both WT and GPER-/- BMDMs. Compared to WT cells, LPS-primed GPER-/- BMDMs exhibit significantly higher basal Ca2+ yet significantly lower ATP-induced Ca2+ release. Consistently, 15-minute treatment with 100 nM G-1 agonist strongly reduces ATP-induced Ca2+ release in WT BMDMs but had no effect in GPER-/- BMDMs. These results suggest a role for GPER in mediating Ca2+ uptake into IP3-sensitive intracellular compartments in BMDMs during LPS priming. In keeping with the known role for mobilization of intracellular Ca2+ in ATP-induced secretion of pro-inflammatory cytokines, preliminary data suggests that short-term G-1 pretreatment reduced IL-1β secretion induced by ATP in LPS-primed BMDMs. Overall, these data indicate a role for GPER in the priming and activation of the NLRP3 inflammasome. This research was supported by Des Moines University IOER Research & Grant Award #03-22-10. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Gaucher disease, the inherited deficiency of lysosomal glucocerebrosidase, is characterized by the presence of glucosylcer-amide macrophages, the accumulation of glucosylceramide in lysosomes and the secretion of inflammatory cytokines. However, the connection between this lysosomal storage and inflammation is not clear. Studying macrophages derived from peripheral monocytes from patients with type 1 Gaucher disease with genotype N370S/N370S, we confirmed an increased secretion of interleukins IL-1β and IL-6. In addition, we found that activation of the inflammasome, a multiprotein complex that activates caspase-1, led to the maturation of IL-1β in Gaucher macrophages. We show that inflammasome activation in these cells is the result of impaired autophagy. Treatment with the small-molecule glucocerebrosidase chaperone NCGC758 reversed these defects, inducing autophagy and reducing IL-1β secretion, confirming the role of the deficiency of lysosomal glucocerebrosidase in these processes. We found that in Gaucher macrophages elevated levels of the autophagic adaptor p62 prevented the delivery of inflammasomes to autophagosomes. This increase in p62 led to activation of p65-NF-kB in the nucleus, promoting the expression of inflammatory cytokines and the secretion of IL-1β. This newly elucidated mechanism ties lysosomal dysfunction to inflammasome activation, and may contribute to the massive organomegaly, bone involvement and increased susceptibility to certain malignancies seen in Gaucher disease. Moreover, this link between lysosomal storage, impaired autophagy, and inflammation may have implications relevant to both Parkinson disease and the aging process. Defects in these basic cellular processes may also provide new therapeutic targets.

Objective: Candida auris (C. auris) is an important fungal pathogen with high rates of transmissibility, mortality, and drug resistance. However, studies on its pathogenicity, host–pathogen interactions, and macrophage immune responses against C. auris are still limited. This study compared the immune response induced by Candida albicans (C. albicans) and C. auris, and explored the inflammation mechanisms of macrophages induced by C. auris. Methods: We used bone marrow derived macrophages (BMDMs) from mouse and peripheral blood mononuclear cells (PBMCs) from human being as the cell model. Flow cytometry was used to compare the phagocytosis rates of C. albicans and C. auris by BMDMs and PBMCs, as well as the differences in reactive oxygen species (ROS) release levels. Quantitative real-time PCR was used to compare the differences in the expression levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-1β. After BMDMs were stimulated with different concentrations of C. auris for various durations, quantitative real-time PCR was used to detect the changes in the expression levels of IL-6, TNF-α, and IL-1β, and ELISA was employed to measure the secretion levels of IL-6, TNF-α, and IL-1β. After co-culturing C. auris with BMDMs for 30 minutes, western blotting was used to detect the phosphorylation levels of Syk, IκBα, and ERK. Laser confocal microscopy was used to observe the nuclear translocation of NF-κB p65, and flow cytometry was utilized to detect the expression of Toll-like receptor 2 (TLR2), TLR4, and Dectin-1 on BMDMs. BMDMs were pre-treated with TLR4 receptor inhibitor (TAK-242), TLR2 receptor inhibitor (C29), and Syk inhibitor (piceatannol) for 1 hour respectively. After BMDMs were stimulated with C. auris, flow cytometry was used to detect ROS and phagocytosis rates, and quantitative real-time PCR and ELISA were used to detect the expression levels of IL-6 and TNF-α mRNA and protein secretion. The t test or one-way analysis of variance was used for statistical analysis. Results: Macrophages showed a lower phagocytosis rate (P < 0.01 for BMDMs; P < 0.001 for PBMCs), ROS production (P < 0.05), and expression of proinflammatory cytokines like IL-6 (P < 0.05), TNF-α (P < 0.01) and IL-1β (P < 0.05) against C. auris when compared with C. albicans. BMDMs were stimulated with C. auris at different concentrations C. auris (BMDMs: C. auris = 1:5, 1:10, 1:20) and for different durations (2, 4, and 8 hours), it was found that the expression levels of IL-6 and TNF-α mRNA were positively correlated with the concentration and duration of C. auris stimulation. The protein levels of IL-6, TNF-α, and IL-1β in the supernatant were all significantly increased. Stimulation of BMDMs by C. auris can induce the phosphorylation of Syk, IκBα, and ERK, the nuclear translocation of NF-κB p65, as well as the expression of TLR2, TLR4, and Dectin-1. By pretreating BMDMs with the inhibitor of TLR4, TLR2, and Syk, we verified that the expression and secretion of IL-6, TNF-α, and IL-1β stimulated by C. auris depended on the activation of TLR2, TLR4, Dectin-1, and downstream signaling pathways. TLR2, TLR4, and Dectin-1 participated in the recognition and phagocytosis of C. auris. Dectin-1 was the most important receptor in mediating immune response, while TLR4 was the most critical receptor in influencing the inflammatory response. Conclusion: C. auris induced a lower level of phagocytosis, production of reactive oxygen species, and expression of inflammatory factors than C. albicans, and that TLR2, TLR4, and Dectin-1 played important roles in the induction of inflammation.

Long Noncoding RNA NEAT1 Regulates Acute Graft-Versus-Host Disease By Promoting Macrophage M1 Polarization through JNK Pathway