LPS-induced Acute Kidney Injury Mice Research Articles

Aromadendrin alleviates LPS-induced kidney apoptosis and inflammation by inhibiting phosphorylation of MAPK and NF-κB signaling pathways.

Excessive inflammation and apoptosis in kidneys are critical players in the pathogenesis of acute kidney injury (AKI). Aromadendrin is a natural flavonoid characterized by anti-inflammatory, anti-apoptotic, and antioxidant actions. Thus, we investigated the roles and mechanisms of aromadendrin in the development of AKI. Lipopolysaccharide (LPS) was used to induce AKI mice, and one hour after LPS challenge, the mice received oral administration of aromadendrin or vehicle. Renal functions were assessed by measuring blood urea nitrogen and creatinine in serum. Histological changes were determined by hematoxylin and eosin staining. Apoptotic cells of renal tissues were detected by TUNEL staining. Gene expression was measured by western blotting and RT-qPCR. Aromadendrin alleviated LPS-induced renal dysfunctions and histological defects in mice. Additionally, aromadendrin suppressed excessive inflammation and tissue apoptosis in the kidneys of LPS-induced AKI mice. Mechanistically, aromadendrin blocked the activation of NF-κB and MAPK pathways in LPS-induced AKI mice. Aromadendrin alleviates LPS-stimulated inflammation and tissue cell apoptosis in kidneys by inactivating the NF-κB and MAPK pathways.

Acteoside and isoacteoside alleviate renal dysfunction and inflammation in lipopolysaccharide-induced acute kidney injuries through inhibition of NF-κB signaling pathway.

Acute kidney injury (AKI) is a sudden loss of renal function with a high mortality rate and inflammation is thought to be the underlying cause. The phenylpropanoid components acteoside (ACT) and isoacteoside (ISO), which were isolated from Cistanche deserticola Y.C.Ma, have been reported to have preventive effects against kidney disorders. This study aimed to investigate the anti-inflammatory properties and protective mechanisms of ACT and ISO. In this investigation, kidney function was assessed using a semi-automatic biochemical analyzer, histopathology was examined using Hematoxylin-Eosin staining and immunohistochemistry, and the concentration of inflammatory cytokines was assessed using an enzyme-linked immunosorbent assay (ELISA) test. In addition, using Western blot and q-PCR, the expression of proteins and genes connected to the NF-κB signaling pathway in mice with lipopolysaccharide (LPS)-induced AKI was found. The findings showed that under AKI intervention in LPS group, ACT group and ISO group, the expression of Rela (Rela gene is responsible for the expression of NFκB p65 protein) and Tlr4 mRNA was considerably elevated (P<0.01), which led to a significant improvement in the expression of MyD88, TLR4, Iκ-Bɑ and NF-κB p65 protein (P<0.001). The levels of Alb, Crea and BUN (P<0.001) increased along with the release of downstream inflammatory factors such as IL-1β, IL-6, Cys-C, SOD1 and TNF-α (P<0.001). More importantly, the study showed that ISO had a more favorable impact on LPS-induced AKI mice than ACT. In conclusion, by inhibiting NF-κB signaling pathway, ACT and ISO could relieve renal failure and inflammation in AKI, offering a fresh possibility for the therapeutic management of the condition.

FTO attenuates LPS-induced acute kidney injury by inhibiting autophagy via regulating SNHG14/miR-373-3p/ATG7 axis

N6‐methyladenosine (m6A) is a master driver of RNA function and implicates in the pathogenesis of renal injury. LncRNA SNHG14 is highly expressed in sepsis patients with acute kidney injury (AKI) and aggravates kidney cell dysfunction. This study aimed to explore whether demethylase FTO affect m6A methylation of SNHG14 in AKI injury and its underlying mechanism. The expression level of FTO was obviously downregulated in sepsis-associated AKI patients compared with normal controls. Mechanistically, FTO overexpression impeded SNHG14 expression by decreasing the stability of SNHG14 in an m6A-dependent manner in LPS-induced HK-2 cells. Additionally, FTO overexpression inhibited cell autophagy and apoptosis while promoting cell viability of LPS-induced HK-2 cells. Moreover, overexpression of FTO inhibited SNHG14 expression and autophagy in LPS-induced AKI mice. Functionally, SNHG14 acts as a competing endogenous RNA (ceRNA) via directly sponging miR-373-3p in LPS induced HK-2 cells. Additionally, miR-373-3p directly targets ATG7. Inhibition of SNHG14 suppresses NF-κB signaling pathway and production of inflammatory cytokines (TNF-α, IL-6, and IL-1β) via miR-373-3p/ATG7 in LPS-induced HK-2 cells. Furthermore, the SNHG14/miR-373-3p/ATG7 interaction network contributes to the regulatory effect of FTO on LPS-induced HK-2 cell viability, apoptosis and autophagy. These results suggested demethylase FTO suppressed the m6A modification of lncRNA SNHG14 and inhibits autophagy in LPS-induced AKI via regulating miR-373-3p/ATG7, which provided an important novel perspective for understanding sepsis-associated AKI and is conducive for developing new therapeutic targets and strategies.

MiR-874-3p Is Identified as a Biomarker for Acute Kidney Injury and Mediates Disease Development via Targeting MSRB3

Introduction: Acute kidney injury (AKI) is a common clinical disease, especially in the intensive care unit. Identification of reliable biomarker is of great clinical significance and benefit the therapy and prevention of AKI. The clinical significance and function of miR-874-3p in AKI development were evaluated in this study aiming to explore a novel biomarker for AKI. Methods: There were 83 AKI patients and 56 healthy individuals included, and the serum samples were collected. The AKI animal models were established via ischemic/reperfusion (I/R) and LPS on C57BL/6 mice. The expression of miR-874-3p was evaluated using PCR, while the potential downstream targets were also validated in AKI mice. The regulatory mechanism of miR-874-3p was investigated in AKI cell model established with HK-2 cell by I/R. Results: miR-874-3p was downregulated in both AKI patients and established AKI mice models. The downregulation of miR-874-3p could discriminate against AKI patients and predict poor prognosis of patients. miR-874-3p was negatively correlated with the levels of serum creatine, blood urea nitrogen, CRP, NEU, and PCT and positively correlated with the eGFR of AKI patients. In I/R- and LPS-induced AKI mice, overexpressing miR-874-3p could alleviate renal dysfunction, oxidative stress, and inflammation induced by AKI. Additionally, miR-874-3p could negatively regulate the expression of MSRB3, which was speculated as the potential mechanism underlying the function of miR-874-3p in AKI. Overexpression of miR-874-3p could alleviate the I/R-induced HK-2 cell apoptosis and decreased proliferation, which was reversed by the upregulation of MSRB3. Conclusion: miR-874-3p served as a diagnostic and prognostic biomarker of AKI and mediate the severity and development of AKI via targeting MSRB3.

Tiliroside Protects against Lipopolysaccharide-Induced Acute Kidney Injury via Intrarenal Renin–Angiotensin System in Mice

Tiliroside, a natural flavonoid, has various biological activities and improves several inflammatory diseases in rodents. However, the effect of Tiliroside on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) and the underlying mechanisms are still unclear. This study aimed to evaluate the potential renoprotective effect of Tiliroside on LPS-induced AKI in mice. Male C57BL/6 mice were intraperitoneally injected with LPS (a single dose, 3 mg/kg) with or without Tiliroside (50 or 200 mg/kg/day for 8 days). Tiliroside administration protected against LPS-induced AKI, as reflected by ameliorated renal dysfunction and histological alterations. LPS-stimulated renal expression of inflammatory cytokines, fibrosis markers, and kidney injury markers in mice was significantly abolished by Tiliroside. This flavonoid also stimulated autophagy flux but inhibited oxidative stress and tubular cell apoptosis in kidneys from LPS-injected mice. Mechanistically, our study showed the regulation of Tiliroside on the intrarenal renin-angiotensin system in LPS-induced AKI mice. Tiliroside treatment suppressed intrarenal AGT, Renin, ACE, and Ang II, but upregulated intrarenal ACE2 and Ang1-7, without affecting plasma Ang II and Ang1-7 levels. Collectively, our data highlight the renoprotective action of Tiliroside on LPS-induced AKI by suppressing inflammation, oxidative stress, and tubular cell apoptosis and activating autophagy flux via the shift towards the intrarenal ACE2/Ang1-7 axis and away from the intrarenal ACE/Ang II axis.

Isolation and characterization of a nephroprotective polysaccharide from Dendrobium chrysotoxum Lindl against LPS-induced acute kidney injury mice

The structure and bioactivity of a novel polysaccharide from Dendrobium Chrysotoxum Lindl (DCP-1) were investigated. The crude polysaccharides of Dendrobium Chrysotoxum Lindl (DCP) were extracted by hot water extraction, and the protein was removed by enzymatic hydrolysis and Sevage. After purification, the chemical structure of polysaccharides was identified by infrared spectroscopy, methylation analysis and nuclear magnetic resonance spectroscopy. Then, a mouse model of acute kidney injury (AKI) was constructed using lipopolysaccharide (LPS), and pretreated with DCP. Structure characterization demonstrated that the number-average molecular weight and mass average molar mass of DCP-1 were 28.43 kDa and 15.00 kDa, respectively. DCP-1 mainly consisted of mannose (37.8 %) and glucose (55.6 %). The main linkage types of DCP-1 were contained 1,4-Linked Manp and 1,4-Linked Glcp. And DCP-1 was demonstrated to be an O-acetylglucomannan with β-ᴅ-configuration in pyranoid form. Besides, the bioactivity of DCP was further investigated. The results showed that DCP exhibited notable anti-inflammatory activity in LPS-induced AKI mice. After treated with DCP, the creatinine (CREA) and urea nitrogen (BUN) in serum were successfully down-regulated in AKI mice. DCP treatment prevented the characteristic morphological changes of LPS-induced renal tubular injury. The results showed that DCP treatment significantly reduced the concentration of oxidative damage indicators (MDA, SOD) and the expression of inflammatory indices (TNF-α, IL-6, MCP-1, COX-2). In general, the newly extracted polysaccharide DCP showed excellent nephroprotective effect, which enabled it to be an ideal natural medicine for kidney diseases therapy.

Puerarin alleviates lipopolysaccharide-induced acute kidney injury in mice by modulating the SIRT1/NF-κB pathway

To investigate the role of the SIRT1/NF-κB pathway in mediating the effect of puerarin against lipopolysaccharide (LPS)-induced acute kidney injury (AKI). Fifteen BALB/C mice were randomized into control group, LPS group and puerarin treatment group, and in the latter two groups, the mice were given an intraperitoneal injection of LPS (5 mg/kg), followed by daily injection of normal saline for 3 days or injection of puerarin (25 mg/kg) given 1 h later and then on a daily basis for 3 days. On day 5 after modeling, the kidney tissues were taken for histological observation and detection of cell apoptosis. The renal function indexes including urea nitrogen (BUN), serum creatinine (Scr) and kidney injury molecule 1 (KIM-1) and the levels of tumor necrosis factor (TNF-α) and interleukin 1β (IL-1β) were measured, and the expressions of SIRT1 and NF-κB-p65(acetyl K310) in the renal tissues were detected. Intraperitoneal injection of LPS caused obvious glomerular capillary dilatation, hyperemia, renal interstitial edema, and renal tubular epithelial cell swelling and deformation in the mice. The mouse models of LPS-induced AKI also showed significantly increased renal tubular injury score and renal cell apoptosis (P < 0.01) with increased serum levels of BUN, Scr, KIM-1, TNF-α and IL-1β (P < 0.01), enhanced renal expressions of TNF-α, IL-1β and NF-κB p65(acetyl K310) (P < 0.01) and lowered renal expression of SIRT1 (P < 0.05). Treatment with puerarin effectively alleviated LPS-induced renal interstitial edema and renal tubular epithelial cell shedding, lowered renal tubular injury score (P < 0.01) and renal cell apoptosis rate (P < 0.01), and decreased serum levels of BUN, Scr, KIM, TNF-α and IL-1β (P < 0.01). Puerarin treatment significantly reduced TNF-α, IL-1β and NF-κB p65 (acetyl K310) expression in the renal tissue (P < 0.05) and increased SIRT1 expression by 17% (P < 0.05) in the mouse models. Puerarin can effectively alleviate LPS-induced AKI in mice possibly by modulating the SIRT1/NF-κB signaling pathway.

EXOSOMAL CIRCVMA21 DERIVED FROM ADIPOSE-DERIVED STEM CELLS ALLEVIATES SEPSIS-INDUCED ACUTE KIDNEY INJURY BY TARGETING MIR-16-5P.

Background: Exosome from adipose-derived stem cells (ADSCs-Exo) has been shown to inhibit the progression of human diseases, including sepsis-related acute kidney injury (AKI). CircVMA21 is considered to be an important regulator for sepsis-related AKI. However, whether ADSCs-Exo affected sepsis-induced AKI by delivering circVMA21 is not clear. Methods: Adipose-derived stem cells were identified by alizarin red staining, oil red O staining, and flow cytometry. Exosome from adipose-derived stem cells was authenticated by transmission electron microscopy, nanoparticle tracking analysis, western blot analysis, and immunofluorescence assay. Cell apoptosis was assessed by flow cytometry, and inflammation cytokine levels were determined by ELISA. Lactate production was assessed using Lactate Acid Content Assay Kit. The expression levels of aerobic glycolysis-related markers, circVMA21 and miR-16-5p, was evaluated by quantitative real time-polymerase chain reaction. Dual-luciferase reporter assay and RIP assay were employed to detect RNA interaction. Animal experiments were used to evaluate the role of ADSCs-Exo on renal function and cell injury in LPS-induced AKI mice model. Results: Exosome from adipose-derived stem cells inhibited LPS-induced HK-2 cell apoptosis, inflammation, and aerobic glycolysis. Knockdown of exosomal circVMA21 derived from ADSCs enhanced HK-2 cell injury induced by LPS. In terms of mechanism, circVMA21 could serve as sponge for miR-16-5p. Besides, miR-16-5p inhibitor reversed the promotion effect of Exo-sh-circVMA21 on LPS-induced cell injury. In addition, ADSCs-Exo protected LPS-induced AKI in mice by increasing circVMA21 expression and decreasing miR-16-5p expression. Conclusion: Exosomal circVMA21 derived by ADSCs relieved LPS-induced AKI through targeting miR-16-5p, which provided a potential molecular target for treating sepsis-related AKI.

#5165 STING CONTRIBUTES TO LPS-INDUCED TUBULAR INFLAMMATION BY ACTIVATING IRE1/XBP1 PATHWAY IN ACUTE KIDNEY INJURY

Abstract Background and Aims Innate immunity and inflammation were recognized as the key factors for the progression of acute kidney injury (AKI) induced by lipopolysaccharide (LPS). Stimulator of interferon genes (STING) has emerged as a critical component of innate immune and inflammatory responses. This study aimed to explore the role of STING in LPS-induced tubular inflammation in AKI. Method 1. The AKI mice models were induced by intraperitoneal injection of LPS. Mice were randomly divided into CTL group, LPS 24 h group and LPS 48 h group: (1) STING protein expression in tubules was detected by IHC staining; (2) STING protein expression in kidney cortices was detected by WB. 2. The tubule-specific STING knockout (STING-cKO) mice were generated. Then WT mice and STING-cKO mice were randomly divided into WT group, WT+LPS group, STING-cKO group and STING-cKO+LPS group: (1) Blood samples and urine samples were collected for Scr, BUN and ACR measurement; (2) Tubular pathological changes were detected by PAS staining; (3) Inflammatory cell infiltration in kidney cortices was detected by IHC and IF staining; (4) Pro-inflammatory cytokines’ mRNA level in kidney cortices was detected by QPCR; (5) IRE1, XBP1, IL-1β and IL-18 protein expression in kidney cortices was detected by WB. 3. HK2 cells were randomly divided into CTL group, si-STING (STING siRNA) group, LPS group, LPS+si-STING group, Ad-IRE1 (IRE1 overexpression plasmid) group, si-STING+ Ad-IRE1 group, LPS+ Ad-IRE1 group and LPS+ si-STING+ Ad-IRE1 group: (1) Pro-inflammatory cytokines’ mRNA level was detected by QPCR; (2) IL-1β, IL-18 protein expression was detected by WB. Results 1. STING was activated in tubules from LPS-induced AKI mice. 2. STING-cKO significantly suppressed LPS-induced renal dysfunction, tubular pathological changes, tubular inflammation and IRE1/XBP1 pathway activation. 3.IRE1 overexpression significantly promoted LPS-activated HK2 cells’ inflammation, even though STING was silenced. Conclusion STING contributes to LPS-induced tubular inflammation by activating IRE1/XBP1 pathway. Targeting STING may be a promising therapeutic strategy for preventing septic AKI.

Vitamin D-VDR (vitamin D receptor) alleviates glucose metabolism reprogramming in lipopolysaccharide-induced acute kidney injury.

Background: Our previous study showed that vitamin D (VD)-vitamin D receptor (VDR) plays a nephroprotective role in lipopolysaccharide (LPS)-induced acute kidney injury (AKI). Recently, glucose metabolism reprogramming was reported to be involved in the pathogenesis of AKI. Objective: To investigate the role of VD-VDR in glucose metabolism reprogramming in LPS-induced AKI. Methods: We established a model of LPS-induced AKI in VDR knockout (VDR-KO) mice, renal proximal tubular-specific VDR-overexpressing (VDR-OE) mice and wild-type C57BL/6 mice. In vitro, human proximal tubular epithelial cells (HK-2 cells), VDR knockout and VDR overexpression HK-2 cell lines were used. Results: Paricalcitol (an active vitamin D analog) or VDR-OE reduced lactate concentration, hexokinase activity and PDHA1 phosphorylation (a key step in inhibiting aerobic oxidation) and simultaneously ameliorated renal inflammation, apoptosis and kidney injury in LPS-induced AKI mice, which were more severe in VDR-KO mice. In in vitro experiments, glucose metabolism reprogramming, inflammation and apoptosis induced by LPS were alleviated by treatment with paricalcitol or dichloroacetate (DCA, an inhibitor of p-PDHA1). Moreover, paricalcitol activated the phosphorylation of AMP-activated protein kinase (AMPK), and an AMPK inhibitor partially abolished the protective effect of paricalcitol in LPS-treated HK-2 cells. Conclusion: VD-VDR alleviated LPS-induced metabolic reprogramming in the kidneys of AKI mice, which may be attributed to the inactivation of PDHA1 phosphorylation via the AMPK pathway.

Oxybaphus himalaicus Mitigates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting TLR4/MD2 Complex Formation.

Acute kidney injury (AKI) is described as the abrupt decrease in kidney function always accompanied by inflammation. The roots of Oxybaphus himalaicus Edgew. have long been used in Tibetan folk medicine for the treatment of nephritis. Nevertheless, modern pharmacological studies, especially about the underlying mechanism of O. himalaicus medications, are still lacking. Here, in lipopolysaccharide (LPS)-induced RAW264.7 macrophages, the O. himalaicus extract (OE) showed significant anti-inflammatory activity with the dose dependently reducing the LPS-stimulated release of nitric oxide and the mRNA level and protein expression of inflammatory cytokines and reversed the activation of nuclear factor kappa B (NF-κB). Co-immunoprecipitation assay indicated that OE inhibited Toll-like receptor 4/myeloid differentiation factor 2 (TLR4/MD2) complex formation and further suppressed both myeloid differentiation factor 88 (MyD88)-dependent and TIR-domain-containing adapter-inducing interferon-β (TRIF)-dependent cascades activation. In addition, OE could restrain NADPH oxidase 2 (NOX2) endocytosis by blocking TLR4/MD2 complex formation to prevent reactive oxygen species production. In LPS-induced AKI mice, OE treatment mitigated renal injury and inflammatory infiltration by inhibiting TLR4/MD2 complex formation. UPLC-MS/MS analysis tentatively identified 41 components in OE. Our results indicated that OE presented significant anti-inflammatory activity by inhibiting TLR4/MD2 complex formation, which alleviated LPS-induced AKI in mice.

Downregulation of miR-29b-3p aggravates podocyte injury by targeting HDAC4 in LPS-induced acute kidney injury.

Sepsis is a severe organ dysfunction disease, usually accompanied by acute kidney injury (AKI). miR-29b-3p was inhibited in sepsis-induced AKI, while its role in AKI was unclear. Therefore, this study determined the role of miR-29b-3p in sepsis-induced AKI, and investigated its underlying mechanism. In this study, the AKI model was established through injecting with lipopolysaccharides (LPS) intraperitoneally. In LPS challenged mice, serum blood urea nitrogen and creatinine were increased, and renal tissues pathological damage was induced. Besides, miR-29b-3p was declined in LPS-induced AKI mice and podocytes. In addition, HDAC4 was elevated in LPS-treated podocytes. Furthermore, upregulated miR-29b-3p attenuated LPS-induced mice podocyte injury, and HDAC4 was identified as a direct target of miR-29b-3p. Moreover, overexpression of miR-29b-3p attenuated LPS-induced AKI in mice. In conclusion, miR-29b-3p was inhibited in LPS-induced AKI. Downregulation of miR-29b-3p aggravated podocyte injury through targeting HDAC4 in LPS-induced AKI. miR-29b-3p may act as a valuable target for AKI therapy.

MiR-494-mediated Effects on the NF-κB Signaling Pathway Regulate Lipopolysaccharide-Induced Acute Kidney Injury in Mice

ABSTRACT Objective To explore the effects of miR-494 inhibition through the NF-κB signaling pathway on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) mouse model. Methods The AKI mice induced by LPS were treated with miR-494 antagomir, and the kidney parameters and indicators of oxidative stress were detected. HE and TUNEL staining were performed to observe the kidney histopathology and the apoptosis in renal tubular epithelial cells (RTECs), respectively. The ROS level was measured using dihydroethidium (DHE) staining. In addition, qRT-PCR, western blotting, immunohistochemistry (IHC), and ELISA were also used to detect gene or protein expression. Results LPS-induced AKI mice injected with the miR-494 antagomir showed reduced blood urea nitrogen (BUN) and serum creatinine (Cr) with improved kidney histopathology. The expression levels of p-IKKα/β, p-IκBα and p65 NF-κB in the nucleus were increased in kidney tissues from the LPS-induced AKI mice, and they were decreased by the miR-494 antagomir. Moreover, the results of IHC showed that the miR-494 antagomir downregulated p65 NF-κB in kidney tissues from the LPS-induced AKI mice, accompanied by decreased levels of TNF-α, IL-1β, IL-6, MDA, NO, and ROS but increased levels of SOD and GSH. In addition, the LPS-induced AKI mice had increased apoptosis in RTECs, as well as increased Caspase-3 and Bax and decreased Bcl-2, which were reversed by the miR-494 antagomir. Conclusions The inhibition of miR-494 could reduce inflammatory responses and improve oxidative stress in kidney tissues from LPS-induced AKI mice by blocking the NF-κB pathway accompanying by reduced apoptosis in RTECs.

Dexmedetomidine Alleviates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting p75NTR-Mediated Oxidative Stress and Apoptosis.

Oxidative stress and apoptosis play a key role in the pathogenesis of sepsis-associated acute kidney injury (AKI). Dexmedetomidine (DEX) may present renal protective effects in sepsis. Therefore, we studied antioxidant effects and the mechanism of DEX in an inflammatory proximal tubular epithelial cell model and lipopolysaccharide- (LPS-) induced AKI in mice. Methods. We assessed renal function (creatinine, urea nitrogen), histopathology, oxidative stress (malondialdehyde (MDA) and superoxide dismutase (SOD)), and apoptosis (TUNEL staining and Cleaved caspase-3) in mice. In vitro experiments including Cleaved caspase-3 and p75NTR/p38MAPK/JNK signaling pathways were evaluated using western blot. Reactive oxidative species (ROS) production and apoptosis were determined using flow cytometry. Results. DEX significantly improved renal function and kidney injury and also revert the substantially increased level of MDA concentrations as well as the reduction of the SOD enzyme activity found in LPS-induced AKI mice. In parallel, DEX treatment also reduced the apoptosis and Cleaved caspase-3 expression evoked by LPS. The expression of p75NTR was increased in kidney tissues of mice with AKI but decreased after treatment with DEX. In cultured human renal tubular epithelial cell line (HK-2 cells), DEX inhibited LPS-induced apoptosis and generation of ROS, but this was reversed by overexpression of p75NTR. Furthermore, pretreatment with DEX significantly downregulated phosphorylation of JNK and p38MAPK in LPS-stimulated HK-2 cells, and this effect was abolished by overexpression of p75NTR. Conclusion. DEX ameliorated AKI in mice with sepsis by partially reducing oxidative stress and apoptosis through regulation of p75NTR/p38MAPK/JNK signaling pathways.

Curcumin reduces LPS-induced septic acute kidney injury through suppression of lncRNA PVT1 in mice

ObjectiveTo investigate the protective effects of curcumin on LPS-induced septic acute kidney injury and to explore its underlying molecular mechanisms. MethodsA mouse model of septic acute kidney injury (AKI) was given an intraperitoneal injection of lipopolysaccharide (LPS), followed by administration of variable levels of curcumin (intragastric). And NRK cells were used as the kidney cell model for all in vitro studies. ResultsCurcumin significantly decreased the levels of serum Scr, BUN, and Cyc c and reduced kidney injury in LPS-induced AKI mice. Kidney tissues of LPS-induced AKI mice showed an increase in PVT1, ED-1, TNF-α, IL-1β, IL-6, p-IkBα/IkBα, p-p65/p65, p-JNK/JNK, and p-c-JUN/c-JUN expression levels; however, treatment with curcumin significantly reduced this effect. Curcumin increased the survival rate NRK cells exposed to LPS-induced inflammation in vitro. Moreover, NRK cells that overexpressed PVT1 had lower survival rates than WT NRK cells obtained from mice that received curcumin treatment after treating with LPS. Additionally, curcumin reduced the LPS-induced increase in Bax, cleaved-caspase3/caspase 3, p-IkBα/IkBα, p-p65/p65, p-JNK/JNK, and p-c-JUN/c-JUN protein expression, and increased Bcl2 protein expression in NRK cells. However, the extent of these changes was low in NRK cells that overexpressed PVT1. ConclusionCurcumin decreased PVT1 expression in LPS-induced septic acute kidney tissues and reduced LPS-induced septic acute kidney injury in mice. This might be related to the inhibition of the JNK/NF-κB pathway by curcumin through suppression of lncRNA PVT1.

Phillyrin Relieves Lipopolysaccharide-Induced AKI by Protecting Against Glycocalyx Damage and Inhibiting Inflammatory Responses.

Damage to the integrity of heparin sulfate (HS) in the endothelial glycocalyx is an important factor of glomerular filtration barrier dysfunction, which is the basic pathological feature of acute kidney injury (AKI). AKI is a common clinical critical illness with few drugs options offering effective treatment. Phillyrin (Phil), the main pharmacological component of Forsythia suspensa, possesses a wide range of pharmacological activities. However, the effects of Phil on lipopolysaccharide (LPS)-induced AKI have yet to be reported. The aim of the present study is to analyze the effects of Phil on HS damage and inflammatory signaling pathways in LPS-induced AKI. Results revealed that Phil reduces pathological changes and improves renal function in LPS-induced AKI. Further analysis indicated that Phil effectively protects against glycocalyx HS degradation in LPS-stimulated EA.hy926 cells in vitro and LPS-induced AKI mice in vivo. The protective effect of Phil on HS damage may be associated with the isolate’s ability to suppress the production of reactive oxygen species, and decrease expression levels of cathepsin L and heparanase in vitro and in vivo. In addition, ELISA and Western blot results revealed that Phil inhibits the activation of the NF-κB and MAPK signaling pathways and decreases the levels of inflammatory cytokines (IL-1β, IL-6, and TNF-α) in LPS-induced ARDS mice. In general, protection against endothelial glycocalyx HS damage and inhibition of inflammatory responses by Phil may be used as treatment targets for LPS-induced AKI.

Dexmedetomidine protects against lipopolysaccharide-induced sepsis-associated acute kidney injury via an α7 nAChR-dependent pathway

Acute kidney injury (AKI) is a clinical syndrome that results in severe tubular damage with high morbidity and mortality. However, there is a lack of effective therapy strategies. Therefore, it is critical to develop effective drugs for AKI. Dexmedetomidine (DEX), a highly selective α2-adrenoreceptor agonist, has neuroprotective, anti-inflammatory and sympatholytic properties. The present study aimed to investigate the effect DEX on attenuating the inflammatory reaction and apoptosis in the kidney tissues of septic mice and to explore its underlying mechanisms. Sepsis-induced AKI mice models were generated via intraperitoneal injection of lipopolysaccaride (LPS). DEX reduced LPS-induced local inflammation and tubular apoptosis, which was aggravated in the pathogenesis of renal dysfunction. Reverse transcription-quantitative polymerase chain reaction and western blot analysis results revealed that the expression of pro-apoptotic genes and inflammatory factors were markedly reduced by DEX pretreatment. Furthermore, the protective role of DEX was markedly inhibited by the α7 nicotinic acetylcholine receptor (nAChR) antagonist α-bungarotoxin. These findings provided novel evidence for the anti-apoptotic and anti-inflammatory effects of DEX in LPS-induced AKI mice through an α7 nAChR-dependent signaling pathway.

Lidanpaidu prescription alleviates lipopolysaccharide-induced acute kidney injury by suppressing the NF-κB signaling pathway

The Lidanpaidu Prescription (LDP), a hospital preparation, composed of Chinese classical preparations, has been reported to have antiendotoxin, anticoagulant and other effects. However, its therapeutic effect on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) and the mechanisms remain unclear. Therefore, we administered LPD pretreatment at different doses to examine the protective effects and mechanisms in LPS-induced AKI in mice. The kidney injury induced by LPS was assessed by histological examination. ELISA was used to detect the levels of inflammatory cytokines. The mRNA expression of the inflammatory genes IKKβ and TNF-α in kidney tissues was assessed by RT-PCR. Finally, Western blot was performed to assess the NF-κB signaling pathway related proteins, and the nuclear translocation of NF-kB P65 was detected by immunofluorescence laser confocal microscopy. The findings suggested that LDP significantly improved at 48 h animal survival (66.7%), compared with the LPS group (26.7%), determined by a Kaplan-Meier analysis. LDP attenuated the kidney histopathological changes induced by LPS and decreased the inflammatory cytokine levels in serum and renal tissue. Moreover, LDP markedly inhibited the expression of inflammatory genes and suppressed the activation of relevant proteins in the nucleus. In summary, these findings suggest that LDP reduces LPS-induced AKI via a mechanism related to the suppression of the NF-κB signaling pathway.

Ferulic acid protects lipopolysaccharide-induced acute kidney injury by suppressing inflammatory events and upregulating antioxidant defenses in Balb/c mice

Sepsis-induced acute kidney injury (AKI) is responsible for 70–80% mortality in intensive care patients due to elevated levels of endotoxin, Lipopolysaccharide (LPS) caused by gram-negative infections. Ferulic acid (FA), a phenolic phytochemical is known for its renal protection on various induced models of nephrotoxicity. However, the curative effect of FA in LPS-induced AKI is not well studied. This study aimed to investigate the effect of FA on LPS-induced AKI in mice model and to understand the protective mechanisms involved, to provide evidence for FA in the treatment of AKI. Balb/c mice were treated with FA at 50 mg/kg and 100 mg/kg dosages after LPS stimulation (10 mg/kg). At the end of the intervention, we determined the concentrations of serum creatinine and blood urea nitrogen, inflammatory cytokines and histopathological changes in animals. Also, the relative protein expression level of TLR4 mediated NF-κB signaling pathway were studied in kidney tissues. FA treated animals showed upregulation of antioxidant defenses and suppression of inflammatory events by inhibiting TLR-4 mediated NFκB activation. However, LPS alone administered group, resulted in rapid renal damage with increased levels of blood urea nitrogen and modest increase in creatinine; decreased antioxidant defenses and release of inflammatory cytokines. The histopathological analysis also revealed the protective action of the FA against sepsis induced fibrosis and renal damage. Our findings demonstrated that FA exhibits marked protective effects on LPS-induced AKI in mice suggesting its chemopotential role for treating AKI in humans.

Esculentoside A inhibits LPS-induced acute kidney injury by activating PPAR-γ

Acute kidney injury (AKI) is a major clinical problem associated with high morbidity and mortality. Esculentoside A (EsA), a kind of saponin isolated from the root of the Chinese herb Phytolaca esculenta, has been reported to have anti-inflammatory effect. In this study, we aimed to investigate the protective effects of EsA on LPS-induced AKI in mice. The protective effects of EsA was evaluated by detecting kidney histological change, blood urea nitrogen (BUN) and creatinine levels, and inflammatory cytokines production. The results showed that EsA significantly attenuated LPS-induced kidney histological change, as well as BUN and creatinine levels. EsA also inhibited LPS-induced TNF-α, IL-1β, and IL-6 production. LPS-induced NF-κB activation was significantly suppressed by treatment of EsA. In addition, EsA up-regulated the expression of PPAR-γ in a dose-dependent manner. In conclusion, EsA protected mice effectively from LPS-induced AKI by PPAR-γ, which subsequently inhibited LPS-induced inflammatory response.