A novel fibrinogenase from Agkistrodon acutus venom protects against LPS-induced endotoxemia via regulating NF-κB pathway

Abstract

Context: Endotoxins including lipopolysaccharide (LPS) could cause endotoxemia which often results in excessive inflammation, organ dysfunction, sepsis, disseminated intravascular coagulation (DIC) or even death. Previously, a novel fibrinogenase (FII) showed protective effects on LPS-induced DIC via activating protein C and suppressing inflammatory cytokines.

Objective: To evaluate whether FII has protective effect on LPS-induced endotoxemia in mice and learn about the role of NF-κB pathway in TNF-α producing process.

Methods: BALB/C mice were intraperitoneally injected (i.p.) with (a) 30?mg/kg LPS, (b) LPS?+?0.3?mg/kg FII, (c) LPS?+?1.0?mg/kg FII, (d) LPS?+?3.0?mg/kg FII or (e) saline. Both survival rate and organ function were tested, including alanine aminotransferase (ALT), blood urine nitrogen (BUN) and tissue section, and TNF-α was examined by ELISA. RAW 264.7 macrophage was administered with (a) LPS, (b) LPS?+?FII, (c) FII alone or (d) saline, and TNF-α and phosphorylation (P)-NF-κB (P65) were determined by Western blot.

Results: The administration of LPS led to 65% mortality rate, a rise of serum TNF-α, BUN and ALT levels, and both liver and renal tissue damage were observed. While FII treatment significantly increased the survival rate of LPS-induced endotoxemia mice model, histopathology and protein analysis results also revealed that FII remarkably protected liver and renal from LPS damage as well as decreasing TNF-α level. In vitro, FII significantly decreased LPS-induced TNF-α production and the expression of P-NF-κB (P65).

Conclusions: Our findings suggested that FII had protective effect on LPS-induced endotoxemia and organ injuries by suppressing the activation of NF-κB which decreased TNF-α level.     

Magnesium isoglycyrrhizinate attenuates D-galactosamine/lipopolysaccharides induced acute liver injury of rat via regulation of the p38-MAPK and NF-κB signaling pathways

Context: Acute hepatic failure involves in serious inflammatory responses and leads to a high mortality. Magnesium isoglycyrrhizinate (MgIG), a magnesium salt of 18-α glycyrrhizic acid (GA) stereoisomer, has been shown anti-inflammatory activity previously.

Objective: This study aimed to investigate the protective effects of MgIG, a hepatocyte protective agent, on D-galactosamine and lipopolysaccharide (D-GaIN/LPS)-induced acute liver injury in rats, and meanwhile explore the molecular mechanism.

Materials and methods: Male Sprague–Dawley (SD) rats were injected with D-GaIN/LPS (800?mg/kgBW/10?μg/kgBW) with or without administration of MgIG (225?mg/kg once 6?h after D-GaIN/LPS injection and MgIG 45?mg/kg twice in another 12?h, intraperitoneal injection). Rats were sacrificed 24?h after D-GaIN/LPS injection, the blood and liver samples were collected for future inflammation and hepatotoxicity analyses.

Results: MgIG significantly inhibited D-GaIN/LPS-induced inflammatory cytokines production and hepatotoxicity as indicated by both diagnostic indicators of liver damage [aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels] and histopathological analysis. Western blot analysis demonstrated that MgIG significantly decreased p38-mitogen activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) activation induced by D-GaIN/LPS.

Conclusion: The results indicated that the protective effects of MgIG on D-GaIN/LPS-induced acute liver injury might be correlated with its capacity to regulate the p38-MAPK and NF-κB signaling pathways.     

Aquaporin-1 attenuates macrophage-mediated inflammatory responses by inhibiting p38 mitogen-activated protein kinase activation in lipopolysaccharide-induced acute kidney injury

Objective

This study was designed to investigate the role of AQP1 in the development of LPS-induced AKI and its potential regulatory mechanisms in the inflammatory responses of macrophages.

Methods

Male Wistar rats were injected intraperitoneally with LPS, and biochemical and histological renal damage was assessed. The levels of inflammatory mediators, macrophage markers and AQP1 in blood and kidney tissues were assessed by ELISA. RTPCR was used to assess changes in the relative levels of AQP1 mRNA induced by LPS. Western blot and immunofluorescence analyses were performed to assay the activation of the p38 MAPK and NF-κB pathways, respectively. The same detection methods were used in vitro to determine the regulatory mechanisms underlying AQP1 function.

Results

AQP1 mRNA levels were dramatically decreased in AKI rats following the increased expression of inflammatory factors. In vitro experiments demonstrated that silencing the AQP1 gene increased inflammatory mediator secretion, altered the classical activation of macrophages, greatly enhanced the phosphorylation of p38 and accelerated the translocation of NF-κB. Furthermore, these results were blocked by doramapimod, a p38 inhibitor. Therefore, these effects were mediated by the increased phosphorylation of p38 MAPK.

Conclusion

Our results suggest that altered AQP1 expression may be associated with the development of inflammation in AKI. AQP1 plays a protective role in modulating acute renal injury and can attenuate macrophage-mediated inflammatory responses by downregulating p38 MAPK activity in LPS-induced RAW264.7 cells. The pharmacological targeting of AQP1-mediated p38 MAPK signalling may provide a novel treatment approach for AKI.

     

Involvement of P450s and nuclear receptors in the hepatoprotective effect of quercetin on liver injury by bacterial lipopolysaccharide

Abstract

Objective: Quercetin (Que), a flavonoid, possesses anti-inflammatory and antioxidant properties. It has been shown to protect against liver injury induced by various factors. This study was designed to investigate the underlying mechanism of its protective effect against lipopolysaccharide (LPS)- induced liver damage.

Methods: Mice were pretreated with Que for 7 consecutive days and then exposed to LPS. To study the hepatoprotective effect of Que, oxidative stress parameters, inflammatory cytokine levels in liver and serum liver function indexes were examined. Protein and mRNA expression of nuclear orphan receptors and cytochrome P450 enzymes were measured by Western Blotting and qPCR, respectively.

Results: Que significantly reduced circulating ALT, AST, ALP, and ameliorated LPS-induced histological alterations. In addition, Que obviously decreased markers of oxidative stress and pro-inflammatory cytokines. Furthermore, Que carried out the hepatoprotective effect via regulation of the expression of nuclear orphan receptors (CAR, PXR) and cytochrome P450 enzymes (CYP1A2, CYP2E1, CYP2D22, CYP3A11).

Conclusions: Our findings suggested that Que pretreatment could ameliorate LPS-induced liver injury.     

Protective effect of cinnamicaldehyde in endotoxin poisoning mice

Context: Several pharmacological studies have shown that cinnamicaldehyde (CA) has anti-inflammatory and anti-tumor effects, but no data show the effects of CA on the endotoxin poisoning.

Objective: In this work, the protective effect of CA in LPS-induced endotoxin poisoning mice was investigated.

Materials and methods: Mice were randomly divided into normal, LPS, LPS +5?mg/kg dexamethasone (DEX), LPS +0.132?g/kg CA, and LPS +0.264?g/kg CA group. Pretreated with CA (0.132 and 0.264?g/kg/day, respectively) for 5 consecutive days before LPS injection. Except the normal group, the other animals were intraperitoneally injected with LPS (15?mg/kg).

Results: Twelve hours after LPS injection, CA significantly reduced the production of pro-inflammatory cytokines (interleukin-18, interleukin-1β, and interleukin-5) and chemokines (macrophage colony stimulating factor, macrophage inflammatory protein-1β) in serum. In addition, the histopathological study indicated that CA attenuates lung injury induced by LPS. Moreover, the numbers of neutrophils were significant decreased and the NF-κB (p65) mRNA level was reduced in lung after treated with CA.

Conclusion: The present data suggest that cinnamicaldehyde can be considered as potential therapeutic candidates for the endotoxin-poisoning-related diseases such as sepsis via its anti-inflammation effects.     

Protective effect of astragaloside IV on lipopolysaccharide-induced cardiac dysfunction via downregulation of inflammatory signaling in mice

Abstract

Context: Astragaloside IV (ASI) is a major and active saponin derivative of Astragalus membranaceus (Fisch) Bge. The anti-inflammatory properties of ASI are important for its cardioprotective effects. However, the molecular mechanisms of the protective effect of ASI on lipopolysaccharide (LPS)-induced cardiac dysfunction is yet to be elucidated.

Objective: This study was designed to investigate the therapeutic effects and possible mechanisms of ASI against LPS-induced septic cardiac dysfunction and inflammation in mice.

Materials and methods: Mice were intraperitoneally injected with ASI (20?mg/kg) for 1 week before LPS challenge (10?mg/kg, i.p.). Left ventricular performance and morphology were analyzed using echocardiography 6?h after LPS induction. Activities of lactate dehydrogenase (LDH) in serum were measured and serum levels of cardiac troponin I (cTnI) were quantified by ELISA. Serum levels of tumor necrosis factor-α (TNF-α), monocyte chemotactic protein 1 (MCP-1), interleukin-6 (IL-6) and IL-1β were also quantified by ELISA. The protein expressions of NF-кB p65 and p-AKT in heart tissues were detected using Western blot analysis.

Results: LPS administration deteriorated cardiac function and was attenuated by ASI pretreatment. ASI attenuated LPS-induced the increase of LDH and cTnI activities in mice. ASI also prevented NF-кB activation and subsequent myocardial inflammatory responses in endotoxemic mice. The effects of ASI were closely associated with the phosphatidylinositol-3-kinase (PI3K/AKT) signaling pathway, as characterized by ASI-induced activation in phospho-Akt. ASI also extended the lifespan of toxemic mice.

Conclusion: ASI significantly attenuated LPS-induced cardiac dysfunction and inflammatory mediator production by inhibiting NF-кB and activating PI3K/AKT signaling pathway.     

人参二醇组皂苷具有与地塞米松类似的改善LPS处理小鼠肾功能的作用*

 目的：研究人参二醇组皂苷（PDS）和地塞米松（DEX）是否具有类似的减轻LPS诱导的小鼠急性肾损伤（AKI）的作用,并探讨它们的作用机制。方法：C57BL/6小鼠随机分为4组,除对照组腹腔注射生理盐水外,其余3组均经腹腔注射LPS 10 mg/kg,PDS组和DEX组小鼠在LPS注射前1 h分别经腹腔注射PDS（25.0 mg/kg）或DEX（2.5 mg/kg）。12 h后麻醉下取血和肾脏组织备生物化学与免疫印迹检测。结果：LPS组小鼠血尿素氮和肌酐含量显著高于对照组（P<0.01）,而PDS组和DEX组则明显低于LPS组（P<0.05）;PDS和DEX上调 LPS处理的小鼠肾组织IκB蛋白的表达,抑制NF-κB信号通路的活化,进而减少TNF-α和IL-6的产生;PDS和DEX均能下调LPS处理的小鼠肾脏诱导型一氧化氮合酶（iNOS）的表达,上调肾组织锰过氧化物歧化酶的表达,减轻肾脏的氧化应激损伤。此外,PDS和DEX均明显上调LPS处理的小鼠肾脏组织细胞核糖皮质激素受体蛋白的含量。结论：人参二醇组皂苷具有与DEX相类似的减轻LPS诱导的小鼠AKI的作用,而且,它们的作用机制相似,但PDS的药效学是否也通过糖皮质受体介导还需进一步研究。     

叉头框蛋白O1在内毒素血症急性肾损伤中的作用

目的:探讨叉头框蛋白O1(forkhead box protein O1,FOXO1)在内毒素血症急性肾损伤(acute kidney injury,AKI)中的作用及相关机制。方法:6~8周龄雄性C57BL/6小鼠腹腔内注射脂多糖(lipopolysaccharide,LPS;10 mg/kg)诱导内毒素血症AKI模型,检测血清肌酐和血尿素氮。利用Western blot、RT-qPCR和免疫荧光等方法检测小鼠肾组织内FOXO1的表达变化。体外培养人近端肾小管上皮细胞HK-2,LPS诱导内毒素血症AKI肾小管上皮细胞模型,利用FOXO1过表达腺病毒感染HK-2细胞,MTT法检测细胞活力;MitoTracker标记线粒体形态学变化;Mito-SOX检测线粒体超氧化物含量改变;检测FOXO1、促凋亡因子Bax及线粒体氧化磷酸化相关分子mRNA变化,以观察线粒体氧化损伤变化情况。结果:内毒素血症AKI小鼠肾组织FOXO1 mRNA及蛋白表达下调。体外LPS刺激可引起HK-2细胞活力下降,线粒体片段化改变,线粒体超氧化物含量升高,FOXO1 mRNA及蛋白表达下调,Bax表达上调,线粒体氧化磷酸化相关分子mRNA下调;而过表达FOXO1可提高肾小管上皮细胞活力,减轻线粒体片段化及氧化磷酸化功能损伤。结论:肾小管上皮细胞FOXO1下调介导了内毒素血症AKI肾小管上皮细胞损伤;过表达FOXO1可减轻内毒素所引起的肾小管上皮细胞线粒体损伤。本研究为内毒素血症AKI的防治提供了新的治疗靶点。     

Effect of combination of vitamin E and umbilical cord-derived mesenchymal stem cells on inflammation in mice with acute kidney injury

Background: The objective of this study is to investigate the effect of combination of umbilical cord-derived mesenchymal stem cell (UC-MSC) and vitamin E (VitE) on inflammation in mice with acute kidney injury (AKI).

Methods: UC-MSCs were isolated from pregnant wistar mice and cultured. A total of 90 female wistar mice were randomly divided into control group, AKI group, AKI?+?VitE group, AKI?+?UC-MSC group, and AKI?+?VitE?+?UC-MSC group (18 mice in each group) which were given no treatment, normal saline, VitE, UC-MSC, and VitE?+?UC-MSC, respectively. The renal pedicles on both sides were clipped for 50?min with micro-artery clips to induce AKI. Six mice were sacrificed at days 1, 3, and 7, while blood and kidney tissues were collected to detect levels of blood urea nitrogen (BUN) and creatinine (Scr). Kidney tissues were stained by HE staining to observe pathological changes; levels of interleukin-lβ, TNF-α, interleukin-10, and β-FGF were measured by ELISA.

Results: Compared with the control group, AKI mice showed higher levels of serum BUN and Scr, tubular swelling and necrosis suggesting that AKI model was successfully established. Mice in AKI?+?VitE group, AKI?+?UC-MSC group, and AKI?+?VitE?+?UC-MSC presented better renal function than mice of AKI group. Mice from AKI?+?VitE?+?UC-MSC group showed the best renal function with the least renal tubular injury (p?p?p?Conclusions: Combination of UC-MSC and VitE significantly inhibited inflammatory reaction in kidney through the regulation of inflammatory cytokines in the microenvironment of kidney with AKI. Combination of UC-MSC and VitE presented therapeutic effect on AKI than the single use of UC-MSC or VitE.     

Immunomodulatory role of recombinant human erythropoietin in acute kidney injury induced by crush syndrome via inhibition of the TLR4/NF-κB signaling pathway in macrophages

Abstract

Objective: The present study aimed to investigate whether recombinant human erythropoietin (rHuEPO) plays an immunomodulatory function by regulating the TLR4/NF-κB signaling pathway.

Materials and methods: C57BL/6 mice were intraperitoneally injected with rHuEPO and, half an hour later, with 50% glycerol at the dose of 7.5?ml/kg to induce crush syndrome (CS)-acute kidney injury (AKI). The levels of TNF-α, IL-1β, IL-6, serum creatinine (Scr), and creatine kinase (CK) were measured. The kidney tissues were analyzed by HE staining, and macrophage infiltration was detected by immunohistochemistry. Double immunofluorescence staining, RT-qPCR, and western blotting were conducted to analyze TLR4/NF-κB p65 expression. Ferrous myoglobin was co-cultured with RAW264.7 cells to mimic crush injury and the production of proinflammatory cytokines. The expression levels of TLR4 and NF-κB p65 were measured.

Results: In vivo study results revealed that rHuEPO ameliorated renal function, tissue damage, production of proinflammatory cytokines, and macrophage infiltration in the kidneys. The protein and mRNA expression levels of genes involved in the TLR4/NF-κB signaling pathway in CS-induced AKI mice were upregulated (p?<?.05). Meanwhile, the expression levels of TLR4, NF-κB p65, and proinflammatory cytokines in RAW264.7 cells were downregulated in CS-AKI mice injected with rHuEPO (p?<?.05).

Conclusions: Our results demonstrated the immunomodulatory capacity of rHuEPO and confirmed that rHuEPO exerts protective effects against CS-induced AKI by regulating the TLR4/NF-κB signaling pathway in macrophages. Therefore, our findings highlight the therapeutic potential of rHuEPO in improving the prognosis of CS-AKI patients.     

Dapagliflozin Ameliorates Lipopolysaccharide Related Acute Kidney Injury in Mice with Streptozotocin-induced Diabetes Mellitus

Sepsis, which is a serious medical condition induced by infection, has been the most common cause of acute kidney injury (AKI) and is associated with high mortality and morbidity. Sodium-glucose cotransporter 2 (SGLT2) inhibitor is a new oral antidiabetic drug that has greatly improved the cardiovascular and renal outcomes in patients with type 2 diabetes independent of its sugar lowering effect, possibly by attenuation of the inflammatory process. We investigated the effect of the SGLT2 inhibitor dapagliflozin on lipopolysaccharide (LPS)-induced endotoxic shock with AKI in streptozotocin-induced diabetic mice. Endotoxin shock with AKI was induced by intravenous injection of 10 mg/kg LPS in C57BL6 mice with streptozotocin-induced diabetic mellitus with or without dapagliflozin treatment. Observation was done for 48 hours thereafter. In addition, NRK-52E cells incubated with LPS or dapagliflozin were evaluated for the possible mechanism. Treatment with dapagliflozin attenuated LPS-induced endotoxic shock associated AKI and decreased the inflammatory cytokines in diabetic mice. In the in vitro study, dapagliflozin decreased the expression of inflammatory cytokines and reactive oxygen species and increased the expressions of AMP-activated protein kinase (AMPK), nuclear factor erythroid-2-related factor, and heme oxygenase 1. These results demonstrated that dapagliflozin can attenuate LPS-induced endotoxic shock associated with AKI; this was possibly mediated by activation of the AMPK pathway.     

Inhibition of NF-κB/TNF-α pathway may be involved in the protective effect of resveratrol against cyclophosphamide-induced multi-organ toxicity

Context: Cyclophosphamide (CyP), an efficient anticancer drug, may damage normal human cells. Resveratrol (RES), a natural polyphenol, has a diverse pharmacological properties.

Objective: To test possible protective effect of RES on multi-organ damage caused by CyP.

Materials and methods: RES (10?mg/kg/day) was administered orally for 8?days. In independent rat groups, CyP toxicity was induced via a single dose of 150?mg/kg i.p. 3?days before the end of experiment, with or without RES treatment.

Results: Compared to control, CyP caused significant increase in organ-to-body weight ratios of heart, kidney and liver, with deterioration in their functional parameters; namely serum creatine kinase, blood urea nitrogen, creatinine, alanine aminotransferase and aspartate aminotransferase. CyP also caused distortion in these organs' histology, with significant tissue oxidative stress, manifested by decrease in reduced glutathione and catalase, as well as increase in malondialdehyde and nitric oxide levels. Furthermore, CyP caused multi-organ inflammatory effects as shown by increased tumor necrosis factor-α levels, as well as up-regulation of nuclear factor-κB expressions. Using RES concurrently with CyP restored heart, kidney and liver functional parameters, as well as their normal histology. RES also reversed oxidative stress, as well as inflammatory signs caused by CyP alone.

Conclusions: RES may be beneficial adjuvant that confers multi-organ protection against CyP toxicity via antioxidant and anti-inflammatory mechanisms.     

Crocin alleviates lipopolysaccharide-induced acute respiratory distress syndrome by protecting against glycocalyx damage and suppressing inflammatory signaling pathways

Objective

To explore the mechanisms of crocin against glycocalyx damage and inflammatory injury in lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) mice and LPS-stimulated human umbilical vein endothelial cells (HUVECs).

Methods

Mice were randomly divided into control, LPS, and crocin?+?LPS (15, 30, and 60 mg/kg) groups. HUVECs were separated into eight groups: control, crocin, matrix metalloproteinase 9 inhibitor (MMP-9 inhib), cathepsin L inhibitor (CTL inhib), LPS, MMP-9 inhib?+?LPS, CTL inhib?+?LPS, and crocin?+?LPS. The potential cytotoxic effect of crocin on HUVECs was mainly evaluated through methylthiazolyldiphenyl-tetrazolium bromide assay. Histological changes were assessed via hemotoxylin and eosin staining. Lung capillary permeability was detected on the basis of wet–dry ratio and through fluorescein isothiocyanate-albumin assay. Then, protein levels were detected through Western blot analysis, immunohistochemical staining, and immunofluorescence.

Results

This study showed that crocin can improve the pulmonary vascular permeability in mice with LPS-induced ARDS and inhibit the inflammatory signaling pathways of high mobility group box, nuclear factor κB, and mitogen-activated protein kinase in vivo and in vitro. Crocin also protected against the degradation of endothelial glycocalyx heparan sulfate and syndecan-4 by inhibiting the expressions of CTL, heparanase, and MMP-9 in vivo and in vitro. Overall, this study revealed the protective effects of crocin on LPS-induced ARDS and elaborated their underlying mechanism.

Conclusion

Crocin alleviated LPS-induced ARDS by protecting against glycocalyx damage and suppressing inflammatory signaling pathways.

     

Licochalcone A Attenuates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting NF-κB Activation

Licochalcone A (Lico A), a flavonoid found in licorice root (Glycyrrhiza glabra), has been reported to have anti-inflammatory activity. However, the protective effects of Lico A on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) remains unclear. In this study, using a mouse model of LPS-induced AKI, we investigated the protective effects and mechanism of Lico A on LPS-induced AKI in mice. LPS-induced kidney injury was assessed by detecting kidney histological study, blood urea nitrogen (BUN), and creatinine levels. The production of inflammatory cytokines TNF-α, IL-6, and IL-1β in serum and kidney tissues was detected by ELISA. The activation of NF-κB was measured by western blot analysis. Our results showed that Lico A dose-dependently attenuated LPS-induced kidney histopathologic changes, serum BUN, and creatinine levels. Lico A also suppressed LPS-induced TNF-α, IL-6, and IL-1β production both in serum and kidney tissues. Furthermore, our results showed that Lico A significantly inhibited LPS-induced NF-κB activation. In conclusion, our results suggest that Lico A has protective effects against LPS-induced AKI and Lico A exhibits its anti-inflammatory effects through inhibiting LPS-induced NF-κB activation.     

The Role of Autophagy in Kidney Inflammatory Injury via the NF-κB Route Induced by LPS

Acute kidney injury (AKI) is a systemic inflammatory response syndrome associated with poor clinical outcomes. No treatments effective for AKI are currently available. Thus, there is an urgent need of development of treatments effective for AKI. Autophagy, an intracellular proteolytic system, is induced in renal cells during AKI. However, whether autophagy is protective or injurious for AKI needs to be clearly clarified. We addressed this question by pharmacological inhibition of autophagy using a mouse model of lipopolysaccharide (LPS) induced-AKI. We found that autophagy was induced in renal cortex of mice during LPS-induced AKI as reflected by a dose-and time-dependent increased accumulation of light chain 3-II (LC3-II), the common marker of autophagy, compared to that of control group; 2) the occurrence of intensive, punctate and increased immunohistochemical staining image of LC3-II in renal cortex; 3) the significant increase in the expression levels of Beclin-1, another key marker of autophagy; 4) the significantly increased levels of plasma urea and serum creatinine and 5) the significant increase in autophagagosome area ratio. We observed that 3-methyladenine (3-MA), a pharmacological inhibitor of autophagy, blocked autophagy flux, alleviated AKI and protected against LPS-induced AKI. LPS triggered kidney inflammation by activation of the canonical NF-κB pathway. This route can be modulated by autophagy. Activation of the canonical NF-κB pathway was reduced in 3-MA+LPS as compared to that in LPS-treated group of mice. Mice pretreated with 3-MA before exposure to LPS showed a reduction in p65 phosphorylation, resulting in the accumulation of ubiquitinated IκB. In conclusion, impairment of autophagy ameliorates LPS-induced inflammation and decreases kidney injury. The accumulation of ubiquitinated IκB may be responsible for this effect.     

The therapeutic effects of cholecystokinin octapeptide on rat liver and kidney microcirculation disorder in endotoxic shock

Objectives: Our previous studies demonstrated that pretreatment with cholecystokinin octapeptide (CCK-8) could alleviate endothelial cell injury and reverse abnormal vascular reactivity as well as reduce LPS-induced inflammation cascades, which suggested that CCK-8 plays a potential role in anti-endotoxic shock. The present study aimed to determine the therapeutic effects of CCK-8 on rat liver and kidney microcirculatory perfusion disorder under endotoxic shock (ES) conditions.

Materials and Methods: Sprague-Dawley rats were induced to lethal endotoxic shock by an injection of LPS. CCK-8 was administered 30?min after LPS injection. Either a specific CCK-1R antagonist or CCK-2R antagonist was injected before CCK-8 treatment. The mean arterial pressure (MAP), liver and kidney microcirculatory perfusion, and heart rate (HR) were recorded with a multi-channel data acquisition system. The serum concentrations of alanine aminotransferase (ALT) and creatinine (Cr) were measured, and the histopathological changes in the liver and kidney were also observed.

Results: Administration of CCK-8 significantly delayed the LPS-induced decreases in not only the liver and kidney microcirculation perfusion but also the HR. The pathology changes induced by LPS in the liver and kidney tissues were significantly mitigated in the LPS?+?CCK-8 group. The levels of ALT and Cr in the serum of the LPS?+?CCK-8 group were obviously lower than those in the LPS group. In addition, the specific antagonist at the CCK-2 receptor (CCK-2R) abrogated the action of CCK-8 significantly.

Conclusions: These results indicated that CCK-8 has potential therapeutic effects on microcirculation failure in an ES rat model via the CCK-2 receptor.     

Inhibition of NLRP3 inflammasome: a new protective mechanism of cinnamaldehyde in endotoxin poisoning of mice

Context: Cinnamaldehyde (CA) has a protective effect in endotoxin poisoning of mice, but there is no direct evidence for the protective effect of CA through inhibition of NLRP3 inflammasome activation in endotoxin poisoning of mice.

Objective: We aimed to investigate the protective mechanism of CA in endotoxin poisoned mice through NLRP3 inflammasome.

Materials and methods: First, we evaluated the anti-inflammatory effect of CA in phorbol-12-myristate acetate–differentiated THP-1 cells through the NLRP3 inflammasome. Second, in a mouse model of lipopolysaccharide (LPS)-induced endotoxin poisoning, CA was administrated for 5 d (once a day) before the 15?mg/kg LPS challenge. Then, the levels of IL-1β in serum were measured, and the effect of CA on the NLRP3 inflammasome activation and the expression of cathepsin B and P2X7R proteins in lung were explored.

Results: In vitro, CA decreased the levels of p20, pro-IL-1β and IL-1β in cell culture supernatants, as well as the expression of NLRP3 and IL-1β mRNA in cells. In vivo, CA decreased IL-1β production in serum. Furthermore, CA suppressed LPS-induced NLRP3, p20, Pro-IL-1β, P2X7 receptor (P2X7R) and cathepsin B protein expression in lung, as well as the expression of NLRP3 and IL-1β mRNA.

Conclusions: CA has a protective effect in the endotoxin poisoned mice through the inhibition of NLRP3 inflammasome activation. Furthermore, CA suppresses the NLRP3 inflammasome activation by inhibiting the expression of cathepsin B and P2X7R protein expression. CA can be considered as a potential therapeutic candidate for diseases involved in endotoxin poisoning such as sepsis.     

Tubeimoside-1 attenuates LPS-induced inflammation in RAW 264.7 macrophages and mouse models

Abstract

Context: Acute lung injury (ALI), characterized by severe hypoxemia, pulmonary edema and neutrophil accumulation in the lung, is a common clinical problem associated with significant morbidity and mortality in shock, sepsis, ischemia reperfusion, etc.

Objective: In this study, we aimed at investigating the protective effect of tubeimoside-1 (TBMS1) on inflammation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and a LPS-induced in vivo lung injury model.

Materials and methods: We evaluated the effect of TBMS1 on LPS-induced production of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β in the culture supernatants of RAW 264.7 cells by enzyme-linked immunosorbent assay. LPS (0.5?mg/kg) was instilled intranasally in phosphate-buffered saline to induce ALI, and the severity of pulmonary injury was evaluated 6?h after LPS challenge.

Results: TBMS1 significantly inhibited the production of the pro-inflammatory cytokines, TNF-α, IL-6 and IL-1β in vitro and in vivo. Pretreatment with TBMS1 markedly attenuated the development of pulmonary edema, histological severities and inflammatory cells infiltration in mice with ALI. In addition, we further demonstrated that TBMS1 exerts an anti-inflammatory effect in vivo model of ALI through suppression of IκB activation and p38/extracellular signal-regulated kinase mitogen-activated protein kinases signaling in a dose-dependent manner.

Discussion and conclusion: Overall, our data suggest that TBMS1 inhibits inflammation both in vitro and in vivo, and may be a potential therapeutic candidate for the prevention of inflammatory diseases.     

Apigenin exhibits anti-inflammatory effects in LPS-stimulated BV2 microglia through activating GSK3β/Nrf2 signaling pathway

Abstract

Objective: Apigenin is a natural flavonoid compound extracted from Matricaria chamomilla. We evaluated the anti-inflammatory effects of apigenin in this study using the Lipopolysaccharide (LPS)-stimulated BV2 microglia.

Methods: BV2 cells were treated with apigenin for 1?h and then treated with LPS. The inflammatory cytokine productions were tested by qRT-PCR and ELISA. The expression of GSK3β, Nrf2, and NF-κB signaling pathways were measured by western blot analysis.

Results: Apigenin significantly attenuated LPS-induced TNF-α, IL-1β, and IL-6 production. Apigenin suppressed LPS-induced NF-κB activation. Furthermore, GSK3β, Nrf2, and HO-1 were concentration-dependently increased by apigenin. The suppression of apigenin on LPS-induced inflammatory response and NF-κB activation were prevented when Nrf2 was knocked out or by GSK3β inhibitor.

Conclusions: Collectively, apigenin suppressed LPS-induced microglia activation via activating GSK3β/Nrf2 signaling pathway.