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

Acute kidney injury (AKI) is a common disease in hospitalized patients, especially in critically ill patients. It is characterised with high morbidity and mortality, and is also an important cause of chronic kidney disease and chronic renal failure. Astragalus propinquus Schischkin and Panax notoginseng (A&P) compound, a famous traditional Chinese medicine, consists of Astragalus propinquus Schischkin, Panax notoginseng, Angelica sinensis, Achyranthes bidentata, and Ecklonia kurome, has been widely used for the treatment of various kidney diseases in the southwest of China. However, the effects of A&P on treatment of AKI and its underlying mechanism are needed to be uncovered. Recent researches reported that Mincle (Macrophage-inducible C-type lectin) plays a key role in renal injury of AKI by regulating the expression and secretion of inflammatory cytokines on macrophage through modulating NF-κB signaling pathway. Here, we aimed to investigate the renoprotective effect of A&P on AKI and whether by inhibiting Mincle. We established a lipopolysaccharide (LPS)-induced Bone Marrow-Derived Macrophage (BMDM) inflammatory cell model and a cisplatin-induced mouse AKI model in vitro and in vivo. Renal histopathology staining was performed to observe kidney morphology. The expression and secretion of inflammatory cytokines were detected by real-time PCR and Enzyme-linked immunosorbent assay. Western blotting was used to detect the protein levels and Flow cytometry performed to detect polarization of macrophage. The results showed that A&P significantly reduced the mRNA expression of IL-1β, IL-6, TNFα and MCP-1 in LPS-stimulated BMDM cells, and secretion of IL-1β and IL-6 in supernatant. The same results were found in Cisplatin-induced AKI kidney and serum after treatment with A&P. The data also showed that A&P strongly reduced the mRNA and protein levels of Mincle in vitro and vivo, and also inhibited the activation of Syk and NF-κB. Notably, A&P down-regulated the M1 macrophage marker iNOS, which may relate to the inhibition of Mincle. Interestingly, both overexpression of Mincle by transfection of pcDNA3.1-Mincle plasmid and administration of TDB (a ligand of Mincle) can significantly abolished the A&P-inhibited inflammation in BMDM, suggesting Mincle pathway play a key role in macrophage inflammation in AKI. Our findings indicated that A&P protected kidney from inhibiting inflammation through down-regulating of Mincle pathway in macrophage in AKI. It provides a potential medicine compound for the treatment of AKI.

Hui D ，Rui-Zhi T ，Jian-Chun L ，Xia Z ，Dan W ，Jun-Ming F ，Li W ... -  《-》

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

Acute kidney injury (AKI) is a common kidney disease with a high risk of death and can develop into chronic kidney disease (CKD) and renal failure eventually. Curcumin, an herbal supplement, has been reported exhibiting a renoprotective role in AKI. However, the underlying mechanism is largely unclear. Recent research showed that Mincle (Macrophage-inducible C-type lectin) maintained M1 macrophage polarization, which plays a key role in kidney injury of AKI through up-regulating the expression and secretion of inflammatory cytokines. Here, we investigated the effects of Curcumin on Mincle expression and macrophage polarization in vitro using lipopolysaccharide (LPS) induced macrophage inflammatory cell model and in vivo using a cisplatin induced murine AKI (cis-AKI) model. Cell activation, inflammatory cytokines expression and secretion, protein levels, macrophage polarization and renal pathology were analyzed. Our results showed that Curcumin markedly reduced the mRNA expression and secretion of IL-1β, IL-6, TNFα and MCP-1 in LPS stimulated RAW264.7 cell and the supernatant. The same results were found in Curcumin treated cis-AKI kidney and blood. The data also demonstrated that Curcumin remarkably down-regulated mRNA expression and protein level of Mincle in cis-AKI kidney and also reduced expression of iNOS (M1 macrophage marker) as well as inhibited the activation of Syk and NF-kB. Interestingly, although Mincle deletion in RAW264.7 cell largely decreased the LPS-induced protein level of iNOS, Curcumin cannot further reduce expression of iNOS without Mincle, indicating that Curcumin inhibits M1 macrophage with a Mincle-dependent pattern. Furthermore, flow cytometry results showed that Curcumin significantly decreased the iNOS positive macrophages and increased the CD206 (M2 macrophage marker) positive macrophages in vivo and in vitro. Our findings prove that Curcumin protects kidney from cisplatin induced AKI through inhibiting Mincle maintained M1 macrophage phenotype, that may provide a specific renoprotection mechanism for Curcumin to develop it as a new therapeutic candidate for AKI.

Tan RZ ，Liu J ，Zhang YY ，Wang HL ，Li JC ，Liu YH ，Zhong X ，Zhang YW ，Yan Y ，Lan HY ，Wang L ... -  《-》

Astragalus mongholicus Bunge and Panax notoginseng formula (A&P) improves renal mesangial cell damage in diabetic nephropathy by inhibiting the inflammatory response of infiltrated macrophages.

Diabetic 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. In 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. Mincle 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. In 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.

Lin X ，Lei XQ ，Yang JK ，Jia J ，Zhong X ，Tan RZ ，Wang L ... -  《BMC Complementary Medicine and Therapies》

Isoliquiritigenin Attenuates UUO-Induced Renal Inflammation and Fibrosis by Inhibiting Mincle/Syk/NF-Kappa B Signaling Pathway.

Chronic kidney disease (CKD) is a global nephrotic syndrome characterized by chronic inflammation, oxidative stress and fibrosis in the kidney. Isoliquiritigenin (ISL), a flavonoid from licorice, has historically been reported to inhibit innate immune responses to inflammation and fibrosis in vivo. However, the effect of ISL on CKD progression is largely unknown. In this study, we employed the inflammatory and fibrotic models of LPS/TGF-β-induced bone marrow-derived macrophages (BMDM) in vitro and unilateral ureteral obstruction (UUO) model in vivo to explore the potential effects and mechanism of ISL on renal inflammation and fibrosis. Our results manifest that ISL improved UUO-induced renal dysfunction and reduced tubular damage with a significantly downregulated mRNA expression and secretion of IL-1β, IL-6, TNF-α and MCP-1 in vitro and in vivo. It is worth noting that ISL can strongly inhibit the mRNA and protein expression of Mincle (macrophage-induced c-type lectin) in BMDM and UUO. ISL inhibited the phosphorylation of Syk and NF-kappa B and simultaneously reduced the expression of α-SMA and Col III in vivo and in vitro. More interestingly, when dealing with TDB, a ligand of Mincle, it revealed significant reversal of protein expression levels as that observed with ISL. The expressions of IL-1β, IL-6, TNF-α, iNOS, p-Syk, p-NF-kappa B, α-SMA and FN in BMDM inflammatory model were significantly upregulated with TDB treatment. This confirms that ISL inhibits inflammation and fibrosis of macrophage by suppressing Mincle/Syk/NF-kappa B signaling pathway. To conclude, ISL protects UUO-induced CKD by inhibiting Mincle-induced inflammation and suppressing renal fibrosis, which might be a specific renal protective mechanism of ISL, making it a novel drug to ameliorate CKD.

Liao Y ，Tan RZ ，Li JC ，Liu TT ，Zhong X ，Yan Y ，Yang JK ，Lin X ，Fan JM ，Wang L ... -  《Drug Design Development and Therapy》

The pattern recognition receptor, Mincle, is essential for maintaining the M1 macrophage phenotype in acute renal inflammation.

Mincle (macrophage-inducible C-type lectin, Clec4e) is a transmembrane pattern recognition receptor involving the innate immunity, but its role in kidney disease is still unexplored. In the obstructed kidney of the unilateral ureteral obstruction model of renal injury, Mincle was specifically detected in the infiltrating M1 macrophages (CD68+iNOS+ cells) on day one but was rapidly reduced following reduction of M1 macrophages during the progression of kidney injury. Interestingly, Mincle-expressing macrophages were progressively increased in the cisplatin-induced acute kidney injury model, where iNOS expression was detected in the CD68+ cells following Mincle induction. Adaptive transfer of Mincle+ M1 macrophages largely promoted cisplatin-induced renal inflammation, which was prevented by the knockdown of Mincle in the transferred cells. Mincle was tightly regulated by TLR4/NF-κB signaling as evidenced by the binding of NF-κB/p65 to the promoter region of Mincle in LPS-primed macrophages. Blocking TLR4 or NF-κB suppressed LPS-induced Mincle expression on macrophages. Importantly, Mincle was found to be essential for maintaining the inflammatory phenotypes of M1 macrophages through the Syk signaling pathway since knockdown of Mincle or inhibition of Syk suppressed LPS-induced IL-1β, MCP-1, and iNOS expression. Thus, Mincle is induced specifically on M1 macrophages, where Mincle-Syk signaling promotes and maintains inflammatory phenotypes of M1 macrophages in acute renal inflammation. Hence, targeting Mincle may be a novel therapy for acute kidney injury associated with M1 macrophages.

Lv LL ，Tang PM ，Li CJ ，You YK ，Li J ，Huang XR ，Ni J ，Feng M ，Liu BC ，Lan HY ... -  《-》