OBJECTIVES: The integrated endoplasmic reticulum stress inhibitor (ISRIB) is a selective inhibitor of the protein kinase R-like endoplasmic reticulum kinase (PERK) signaling pathway within endoplasmic reticulum stress (ERS) and can improve spatial and working memory in aged mice. Although ERS and oxidative stress are tightly interconnected, it remains unclear whether ISRIB alleviates cognitive impairment by restoring the balance between ERS and oxidative stress. This study aims to investigate the effects and mechanisms of ISRIB on lipopolysaccharide (LPS)-induced cognitive impairment in mice. METHODS: Eight-week-old male ICR mice were randomly divided into 3 groups: Normal saline (NS) group, LPS group, and ISRIB+LPS group. NS and LPS groups received daily intraperitoneal injections of normal saline for 7 days; on day 7, LPS group mice received intraperitoneal LPS (0.83 mg/kg) to establish a cognitive impairment model. ISRIB+LPS group received ISRIB (0.25 mg/kg) intraperitoneally for 7 days, with LPS injected 30 minutes after ISRIB on day 7. Cognitive ability was evaluated by the novel place recognition test (NPRT). Real-time fluorogenic quantitative PCR (RT-qPCR) was used to detect changes in nitric oxide synthase (NOS), superoxide dismutase-1 (SOD-1), and catalase (CAT) gene expression in the hippocampus and prefrontal cortex. Oxidative stress markers malondialdehyde (MDA), glutathione (GSH), and oxidized glutathione (GSSG), were measured in hippocampal and prefrontal cortex tissues. RESULTS: Compared with the NS group, mice in LPS group showed a significant reduction in novel place recognition ratio, upregulation of hippocampal NOS-1 and NOS-2 mRNA, downregulation of SOD-1 and CAT mRNA, increased MDA and GSSG, decreased GSH, and reduced GSH/GSSG ratio (all P<0.05). Compared with the LPS group, mice in ISRIB+LPS group exhibited significantly improved novel place recognition, downregulated NOS-1 and NOS-2 mRNA, upregulated SOD-1 and CAT mRNA, decreased MDA and GSSG, increased GSH, and an elevated GSH/GSSG ratio in the hippocampus (all P<0.05). No significant changes were observed in the prefrontal cortex. CONCLUSIONS ISRIB improves LPS-induced cognitive impairment in mice by restoring the oxidative/antioxidant balance in the hippocampus.
Animals ; Lipopolysaccharides ; Male ; Mice, Inbred ICR ; Cognitive Dysfunction/drug therapy* ; Mice ; Oxidative Stress/drug effects* ; Endoplasmic Reticulum Stress/drug effects* ; Hippocampus/drug effects* ; Nitric Oxide Synthase Type II/genetics* ; Guanidines/pharmacology* ; eIF-2 Kinase/antagonists & inhibitors* ; Signal Transduction/drug effects* ; Superoxide Dismutase/metabolism*

OBJECTIVE: To investigate the protective effect of protein kinase C (PKC) inhibitor rottlerin on rat renal vascular endothelial injury induced by lipopolysaccharide (LPS). METHODS: Rat renal microvascular endothelial cells cultured for 3-6 generations were divided into three groups according to random number table: blank control group in which cells were not challenged, LPS group in which cells were only stimulated by LPS 10 mg/L for 24 hours, and PKC inhibitor group in which cells were treated with PKC inhibitor rottlerin 2 μmol/L 30 minutes before LPS stimulation. The levels of tumor necrosis factor-α (TNF-α) and interleukins (IL-1β, IL-8) were determined by enzyme-linked immunosorbent assay (ELISA). Monolayer permeability was determined by Transwell assay. The expressions of PKC, RhoA and vascular endothelial-cadherin (VE-cadherin) were detected by Western Blot. The morphological characteristic and distribution of F-actin was measured by laser confocal fluorescence microscope. RESULTS: Compared with blank control group, the levels of inflammatory cytokines at 24 hours after 10 mg/L LPS stimulation were significantly increased in LPS group [TNF-α (ng/L): 397.3±25.4 vs. 46.8±8.9, IL-1β (ng/L): 76.7±11.2 vs. 12.6±3.2, IL-8 (ng/L): 574.5±31.4 vs. 73.2±9.6, all P < 0.05], the permeability of endothelial cells was significantly increased (A value: 1.32±0.03 vs. 0.36±0.02, P < 0.05), while the expressions of PKC and RhoA were significantly up-regulated (PKC/β-actin: 0.88±0.02 vs. 0.61±0.03, RhoA/β-actin: 0.96±0.01 vs. 0.49±0.03, both P < 0.05), VE-cadherin expression was significantly down-regulated (VE-cadherin/β-actin: 0.51±0.01 vs. 0.72±0.04, P < 0.05), and the F-actin distribution disorder had obvious stress fiber formation. Compared with LPS group, the levels of inflammatory cytokines were significantly lowered in PKC inhibitor group [TNF-α (ng/L): 127.4±14.6 vs. 397.3±25.4, IL-1β(ng/L): 43.2±7.8 vs. 76.7±11.2, IL-8 (ng/L): 212.7±18.2 vs. 574.5±31.4, all P < 0.05], the permeability of endothelial cells was significantly decreased (A value: 0.81±0.02 vs. 1.32±0.03, P < 0.05), the expressions of PKC and RhoA were significantly down-regulated (PKC/β-actin: 0.44±0.03 vs. 0.88±0.02, RhoA/β-actin: 0.63±0.05 vs. 0.96±0.01, both P < 0.05), the VE-cadherin expression was significantly up-regulated (VE-cadherin/β-actin: 0.69±0.03 vs. 0.51±0.01, P < 0.05), and the F-actin remodeling and stress fiber formation were significantly reduced. CONCLUSIONS PKC inhibitor could significantly attenuate the damage of vascular endothelial barrier induced by LPS, and plays an important role in endothelial cell barrier.
Acute Kidney Injury/prevention & control* ; Animals ; Endothelium, Vascular/drug effects* ; Interleukin-1beta ; Lipopolysaccharides/toxicity* ; Protein Kinase C/antagonists & inhibitors* ; Protein Kinase Inhibitors/pharmacology* ; Random Allocation ; Rats

OBJECTIVE: To investigate the role of cathepsin B in hepatic Kupffer cells (KCs) in activating Toll-like receptor 4(TLR- 4)-independent inflammatory pathways in mice with lipopolysaccharide (LPS)-induced sepsis. METHODS: Eighteen wild-type (WT) mice and 18 TLR4-knockout (TLR4) mice were both divided into 3 groups for intraperitoneal injections of a lethal dose (54 mg/kg) of LPS, LPS and CA-074(a cathepsin B inhibitor), or normal saline, and the survival of the mice were observed. Another 36 WT mice and 36 TLR4mice were also divided into 3 groups and subjected to intraperitoneal injections of normal saline, 20 mg/kg LPS, or LPS with CA-074 pretreatment.After the treatments, KCs were collected from the mice for assessing the protein level and activity of cathepsin B.The histopathological changes of the liver were observed with HE staining, and the serum levels of IL-1α, IL-1β, TNF-α and IL-18 were detected. RESULTS: Compared with the WT mice,TLR4mice receiving the lethal dose of LPS had significantly longer survival time (up to 84 h) after the injection,but were still unable to fully resist LPS challenge.CA-074 pretreatment prolonged the survival time of WT mice and TLR4mice to 60 h and 132 h,respectively.In the mouse models of sepsis,20 mg/kg LPS induced significantly enhanced activity of cathepsin B without affecting its expression level in the KCs (<0.05) and increased the serum levels of the inflammatory cytokines.CA-074 pretreatment of the mice obviously lessened the detrimental effects of LPS in TLR4mice by significantly lowering cathepsin B activity in the KCs,alleviating hepatocyte apoptosis and reducing the serum levels of inflammatory cytokines. CONCLUSIONS Cathepsin B plays an important role in activating TLR4-independent inflammatory pathways in mice with LPS-induced sepsis.
Animals ; Cathepsin B ; antagonists & inhibitors ; physiology ; Dipeptides ; pharmacology ; Gene Knockout Techniques ; Hepatocytes ; Inflammation ; metabolism ; Interleukin-18 ; blood ; Interleukin-1alpha ; blood ; Interleukin-1beta ; blood ; Kupffer Cells ; metabolism ; Lipopolysaccharides ; Liver ; pathology ; Mice ; Sepsis ; etiology ; metabolism ; Toll-Like Receptor 4 ; genetics ; Tumor Necrosis Factor-alpha ; blood

Dendrobii Caulis (DC), named 'Shihu' in Chinese, is a precious herb in traditional Chinese medicine. It is widely used to nourish stomach, enhance body fluid production, tonify "Yin" and reduce heat. More than thirty Dendrobium species are used as folk medicine. Some compounds from DC exhibit inhibitory effects on macrophage inflammation. In the present study, we compared the anti-inflammatory effects among eight Dendrobium species. The results provided evidences to support Dendrobium as folk medicine, which exerted its medicinal function partially by its inhibitory effects on inflammation. To investigate the anti-inflammatory effect of Dendrobium species, mouse macrophage cell line RAW264.7 was activated by lipopolysaccharide. The nitric oxide (NO) level was measured using Griess reagent while the pro-inflammatory cytokines were tested by ELISA. The protein expressions of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and mitogen-activated protein kinases (MAPKs) phosphorylation were evaluated by Western blotting analysis. Among the eight Dendrobium species, both water extracts of D. thyrsiflorum B.S.Williams (DTW) and D. chrysotoxum Lindl (DCHW) showed most significant inhibitory effects on NO production in a concentration-dependent manner. DTW also significantly reduced TNF-α, MCP-1, and IL-6 production. Further investigations showed that DTW suppressed iNOS and COX-2 expression as well as ERK and JNK phosphorylation, suggesting that the inhibitory effects of DTW on LPS-induced macrophage inflammation was through the suppression of MAPK pathways. In conclusion, D. thyrsiflorum B.S.Williams was demonstrated to have potential to be used as alternative or adjuvant therapy for inflammation.
Animals ; Anti-Inflammatory Agents ; pharmacology ; Cyclooxygenase 2 ; genetics ; Cytokines ; metabolism ; Dendrobium ; chemistry ; Gene Expression Regulation, Enzymologic ; drug effects ; Inflammation ; chemically induced ; drug therapy ; Lipopolysaccharides ; Macrophages ; drug effects ; enzymology ; Mice ; Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; genetics ; metabolism ; Nitric Oxide ; analysis ; Nitric Oxide Synthase Type II ; genetics ; Phosphorylation ; drug effects ; Plant Extracts ; pharmacology ; RAW 264.7 Cells ; Signal Transduction ; drug effects

BACKGROUNDSurfactant protein-A (SP-A) contributes to the regulation of sepsis-induced acute kidney injury. In a previous study, we demonstrated that the expression of SP-A in the human renal tubular epithelial (HK-2) cells can be stimulated by lipopolysaccharide (LPS). The present study evaluated the possible signal-transducing mechanisms of LPS-induced SP-A biosynthesis in the HK-2 cells.

METHODSTetrazolium salt colorimetry (MTT) assay was used to detect cell viability of HK-2 cells after LPS stimulation on different time points. HK-2 cells were stimulated with 100 ng/ml of LPS for different durations to determine the effects of LPS on SP-A and toll-like receptor 4 (TLR4) messenger RNA (mRNA) expression, as well as phosphorylation of mitogen-activated/extracellular signal-regulated kinase (MEK) 1, extracellular signal-regulated kinase 1/2 (ERK1/2), p38 mitogen-activated protein kinase (p38MAPK), and nuclear factor-kappa B (NF-κB) inhibitor-alpha (IkB-α). Then, HK-2 cells were pretreated with CLI-095, a TLR4 inhibitor, to analyze mRNA and protein levels of SP-A and TLR4 and expression of NF-κB in the cytoplasm and nucleus of HK-2 before LPS exposure.

RESULTSHK-2 cells exposed to 100 ng/ml of LPS for 1, 6, and 24 h did not affect cell viability which showed no toxic effect of 100 ng/ml LPS on cells (P = 0.16); however, the biosynthesis of SP-A mRNA and protein in HK-2 cells was significantly increased (P = 0.02). As to the mechanism, LPS enhanced transmembrane receptor TLR4 protein expression. Sequentially, LPS time dependently augmented phosphorylation of MEK1, ERK1/2, and p38MAPK. In addition, levels of phosphorylated IκB-α and nuclear NF-κB were augmented with LPS exposure for 2 h. LPS-induced SP-A and TLR4 mRNA as well as NF-κB expression were significantly inhibited by pretreatment with CLI-095.

CONCLUSIONSThe present study exhibited that LPS can increase SP-A synthesis in human renal epithelial cells through sequentially activating the TLR4-related MEK1-ERK1/2-NF-κB-dependent pathway.

Cell Line ; Cell Survival ; drug effects ; physiology ; Colorimetry ; Humans ; Kidney ; cytology ; metabolism ; Lipopolysaccharides ; toxicity ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; NF-kappa B ; metabolism ; Pulmonary Surfactant-Associated Protein A ; metabolism ; Sulfonamides ; pharmacology ; Tetrazolium Salts ; chemistry ; Toll-Like Receptor 4 ; antagonists & inhibitors ; metabolism

To investigate the anti-pyretic and anti-endotoxin effect of Chinese herb medicine Jinhuaqingre capsules.Thirty healthy male New Zealand rabbits with lipopolysaccharide-induced fever were divided into 5 groups (6 rabbits in each): animals in model group were given normal saline by gavage, animals in positive control group were given aspirin (0.2 g/kg), and animals in Jinhuaqingre groups were given Jinhuaqingre capsules 6.0, 3.0 or 1.5 g/kg, respectively. The changes in body temperature of rabbits were observed. Fifty healthy Kunming mice were divided into 5 groups (10 mice in each): mice in model group were given normal saline by gavage, mice in positive control group were given aspirin (0.2 g/kg), and those in Jinhuaqingre groups were given Jinhuaqingre capsules 6.0, 3.0, 1.5 g/kg, respectively. Matrix coloration method was used to detect the degradation rate of endotoxin in mice.The body temperature in rabbits of high and medium dose Jinhuaqingre capsule groups declined significantly 60 min after drug administration, and the temperature of high-dose group returned to the baseline after 300 min; while the body temperature of low-dose group started to decline at 180 min after drug administration. The endotoxin degradation rates in mice of high, medium and low dose groups was (56.73±3.12)%, (47.23±1.77)% and (21.08±2.30)% at 30 min after drug administration; those were (82.76±1.00)%, (64.75±1.77)% and (38.21±1.57)% at 60 min after drug administration, respectively.Chinese herb medicine Jinhuanigre capsules have anti-pyretic and anti-endotoxin effects, which may provide a new option for the treatment of heat-toxin syndrome.
Animals ; Antitoxins ; pharmacology ; Aspirin ; therapeutic use ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; Fever ; chemically induced ; drug therapy ; Lipopolysaccharides ; antagonists & inhibitors ; Male ; Medicine, Chinese Traditional ; Mice ; Rabbits ; Sodium Chloride ; therapeutic use

The present study was designed to characterize the polyphenols isolated from Acacia mearnsii bark crude extract (B) and fractions (B1-B7) obtained by high-speed counter-current chromatography (HSCCC) and evaluate their anti-inflammatory and carbolytic enzymes (α-glucosidase and α-amylase) inhibitory activities. Fractions B4, B5, B6, B7 (total phenolics 850.3, 983.0, 843.9, and 572.5 mg·g, respectively; proanthocyanidins 75.7, 90.5, 95.0, and 44.8 mg·g, respectively) showed significant activities against reactive oxygen species (ROS), nitric oxide (NO) production, and expression of pro-inflammatory genes interleukin-1β (IL-1β) and inducible nitric oxide synthase (iNOS) in a lipopolysaccharide (LPS)-stimulated mouse macrophage cell line RAW 264.7. All the extracts suppressed α-glucosidase and α-amylase activities, two primary enzymes responsible for carbohydrate digestion. A. mearnsii bark samples possessed significantly stronger inhibitory effects against α-glucosidase enzyme (IC of 0.4-1.4 μg·mL) than the pharmaceutical acarbose (IC 141.8 μg·mL). B6 and B7 (IC 17.6 and 11.7 μg·mL, respectively) exhibited α-amylase inhibitory activity as efficacious as acarbose (IC 15.4 μg·mL). Moreover, B extract, at 25 µg·mL, significantly decreased the non-mitochondrial oxidative burst that is often associated with inflammatory response in human monocytic macrophages.
Acacia ; chemistry ; Animals ; Anti-Inflammatory Agents ; isolation & purification ; pharmacology ; Carbohydrate Metabolism ; drug effects ; Glycoside Hydrolase Inhibitors ; pharmacology ; Inflammation ; metabolism ; Interleukin-1beta ; metabolism ; Lipopolysaccharides ; Macrophages ; drug effects ; Mice ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Plant Bark ; chemistry ; Plant Extracts ; chemistry ; pharmacology ; Polyphenols ; isolation & purification ; pharmacology ; Proanthocyanidins ; pharmacology ; RAW 264.7 Cells ; alpha-Amylases ; antagonists & inhibitors ; alpha-Glucosidases ; metabolism

Lipopolysaccharides (LPS) contamination in herbal crude polysaccharides is inevitable. The present study was performed to explore the effect of polymyxin B on abolishing the influence of LPS contamination in mononuclear cells. LPS was pretreated with polymyxin B sulfate (PB) at different concentrations for 1, 5 or 24 h, and then used to stimulate RAW264.7 and mouse peritoneal macrophages (MPMs). The nitric oxide (NO) and tumor necrosis factor-α (TNF-α) in cell culture supernatant, as the indications of cell response, were assayed. Bupleurum chinensis polysaccharides (BCPs) with trace amount contamination of LPS was treated with PB. 30 μg·mL of PB, treating LPS (10 and 1 000 ng·mL in stimulating RAW264.7 and MPMs respectively) at 37 °C for 24 h, successfully abolished the stimulating effect of LPS on the cells. When the cells were stimulated with LPS, BCPs further promoted NO production. However, pretreated with PB, BCPs showed a suppression of NO production in MPMs and no change in RAW264.7. In the in vitro experiments, LPS contamination in polysaccharide might bring a great interference in assessing the activity of drug. Pretreatment with PB (30 μg·mL) at 37 °C for 24 h was sufficient to abolish the effects of LPS contamination (10 and 1 000 ng·mL).
Animals ; Bupleurum ; chemistry ; Drug Contamination ; Drugs, Chinese Herbal ; analysis ; pharmacology ; Lipopolysaccharides ; analysis ; antagonists & inhibitors ; Macrophages ; drug effects ; metabolism ; Mice ; Nitric Oxide ; metabolism ; Polymyxin B ; analysis ; pharmacology ; Polysaccharides ; analysis ; pharmacology ; Tumor Necrosis Factor-alpha ; metabolism

BACKGROUNDAn acute respiratory distress syndrome (ARDS) is still one of the major challenges in critically ill patients. This study aimed to investigate the effect of inhibiting c-Jun N-terminal kinase (JNK) on ARDS in a lipopolysaccharide (LPS)-induced ARDS rat model.

METHODSThirty-six rats were randomized into three groups: control, LPS, and LPS + JNK inhibitor. Rats were sacrificed 8 h after LPS treatment. The lung edema was observed by measuring the wet-to-dry weight (W/D) ratio of the lung. The severity of pulmonary inflammation was observed by measuring myeloperoxidase (MPO) activity of lung tissue. Moreover, the neutrophils in bronchoalveolar lavage fluid (BALF) were counted to observe the airway inflammation. In addition, lung collagen accumulation was quantified by Sircol Collagen Assay. At the same time, the pulmonary histologic examination was performed, and lung injury score was achieved in all three groups.

RESULTSMPO activity in lung tissue was found increased in rats treated with LPS comparing with that in control (1.26 ± 0.15 U in LPS vs. 0.77 ± 0.27 U in control, P < 0.05). Inhibiting JNK attenuated LPS-induced MPO activity upregulation (0.52 ± 0.12 U in LPS + JNK inhibitor vs. 1.26 ± 0.15 U in LPS, P < 0.05). Neutrophils in BALF were also found to be increased with LPS treatment, and inhibiting JNK attenuated LPS-induced neutrophils increase in BALF (255.0 ± 164.4 in LPS vs. 53 (44.5-103) in control vs. 127.0 ± 44.3 in LPS + JNK inhibitor, P < 0.05). At the same time, the lung injury score showed a reduction in LPS + JNK inhibitor group comparing with that in LPS group (13.42 ± 4.82 vs. 7.00 ± 1.83, P = 0.001). However, the lung W/D ratio and the collagen in BALF did not show any differences between LPS and LPS + JNK inhibitor group.

CONCLUSIONSInhibiting JNK alleviated LPS-induced acute lung inflammation and had no effects on pulmonary edema and fibrosis. JNK inhibitor might be a potential therapeutic medication in ARDS, in the context of reducing lung inflammatory.

Animals ; Anthracenes ; therapeutic use ; Collagen ; metabolism ; JNK Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; metabolism ; Lipopolysaccharides ; toxicity ; Lung ; drug effects ; metabolism ; pathology ; Male ; Rats ; Respiratory Distress Syndrome, Adult ; chemically induced ; drug therapy ; Signal Transduction ; drug effects

BACKGROUNDCervical cancer is the second most common cancer of woman in the world, and human papillomavirus (HPV) infection plays an important role in the development of most of the cases. IκB kinase β (IKKβ) is a kinase-mediating nuclear factor kappa B (NF-κB) activation by phosphorylating the inhibitor of NF-κB (IκB) and is related by some diseases caused by virus infection. However, there is little known about the correlation between IKKβ and HPV infection in cervical cancer. This study aimed to investigate the expression of IKKβ protein in cervical cancer tissues and effects of inflammation on HPV positive or negative cervical cancer cells through detecting the expression of IKKβ, IκBα, p53, and p21 proteins after treated with lipopolysaccharide (LPS) to mimic bacterial infection. We also examined the effects of LPS on cervical cancer cells after blocking IKKβ with pharmacological inhibitor.

METHODSThirty-six matched specimens of cervical cancer and adjacent normal tissues were collected and analyzed in the study. The expression of IKKβ in the tissue specimens was determined by immunohistochemical staining. In addition, Western blot was used to detect the expression level changes of IKKβ, IκBα, p53, and p21 after LPS stimulated in the HPV16+ (SiHa) and HPV16- (C33A) cervical cancer cell lines. Furthermore, the effects of IKKβ inhibitor SC-514 on LPS-induced expression change of these proteins were investigated.

RESULTSThe expression of IKKβ was higher in cervical cancer than adjacent normal tissues, and there was no significant difference between tumor differentiation, size, and invasive depth with IKKβ expression. The LPS, which increased the expression level of IKKβ protein but decreased in the IκBα, p53 and p21 proteins, was illustrated in HPV16+ (SiHa) but not in HPV16- (C33A) cells. Moreover, IKKβ inhibitor SC-514 totally reversed the upregulation of IKKβ and downregulation of p53 and p21 by LPS in SiHa cells.

CONCLUSIONSIKKβ may mediate the downregulation of p53 and p21 by LPS in HPV16+ cervical cancer cells.

Cell Line, Tumor ; Down-Regulation ; drug effects ; Female ; Human papillomavirus 16 ; pathogenicity ; Humans ; I-kappa B Kinase ; antagonists & inhibitors ; metabolism ; Lipopolysaccharides ; pharmacology ; Proto-Oncogene Proteins p21(ras) ; metabolism ; Thiophenes ; pharmacology ; Tumor Suppressor Protein p53 ; metabolism ; Uterine Cervical Neoplasms ; metabolism ; virology