Emodin alleviates intestinal ischemia/reperfusion-induced lung injury by upregulating HO-1 expression via PI3K/AkT pathway.

BACKGROUND: Emodin, a natural anthraquinone derivative found in various Chinese medicinal herbs, has been proved to be an effective therapeutic agent in the treatment of many diseases. However, its effect on lung injury after intestinal ischemia/reperfusion injury remains unknown. This research was designed to investigate whether emodin protects against intestinal ischemia/reperfusion-induced lung injury and to elucidate the underlying molecular mechanisms in vivo and in vitro. METHODS: Intestinal ischemia/reperfusion injury was induced by occluding the superior mesenteric artery in mice, and mouse lung epithelial-12 cells were subjected to oxygen-glucose deprivation and reoxygenation to establish an in vitro model. RESULTS: Our data indicated that emodin treatment reduced intestinal ischemia/reperfusion-induced oxidative stress, inflammation and apoptosis in lung tissues and alleviated lung injury. However, the protective effects of emodin on intestinal ischemia/reperfusion-induced lung injury were reversed by the protein kinase B inhibitor triciribine or the heme oxygenase-1 inhibitor tin protoporphyrin IX. The protein kinase inhibitor triciribine also downregulated the expression of heme oxygenase-1. CONCLUSION: In conclusion, our data suggest that emodin treatment protects against intestinal ischemia/reperfusion-induced lung injury by enhancing heme oxygenase-1 expression via activation of the PI3K/protein kinase pathway. Emodin may act as a potential therapeutic agent for the prevention and treatment of lung injury induced by intestinal ischemia/reperfusion.

Circ_0005075 targeting miR-151a-3p promotes neuropathic pain in CCI rats via inducing NOTCH2 expression.

Neuropathic pain is a most challenging diseases worldwide, caused by the injury of nerve system. CircularRNAs (circRNAs) are revealed to be involved in various diseases, includingneuropathic pain. However, the waycircRNAsparticipate in the progress ofneuropathic painstill needs further study. Identifyingthe possible circRNAexpression patterns of neuropathic painis of great significance to understand its underlying mechanism. Previously, circ_0005075 has been regarded as an important oncogene in multiple cancers and it has been characterized as an inflammation­associated circRNA in various processes. Nevertheless, the functional role of circ_0005075 in neuropathic pain development is still poorly known. In our present study, we observed circ_0005075 was obviously increased in CCI rat models. Knockdown of circ_0005075 repressed thebehaviors of neuropathic pain including mechanical and thermal hyperalgesia. Moreover, loss of circ_0005075 could repress the neuroinflammation via targeting COX-2, IL-6 and TNF-α whereas inducing IL-10 in vivo. Additionally, we predicted miR-151a-3p as the potential target of circ_0005075 using bioinformatics analysis. We displayed that miR-151a-3p was greatly reduced in CCI rats and circ_0005075 reversed the repressive effect of miR-151a-3p on neuropathic pain. For another, NOTCH2 has been shown to induce a variety of intracellular responses correlated withneuropathic pain. Here, we found NOTCH2 expression was strongly induced in CCI rats and miR-151a-3p. In addition, circ_0005075 significantly rescued NOTCH2 expression, which could be repressed by miR-151a-3p. To sum up, we indicated that loss ofcirc_0005075relieved neuropathic pain progression by inducement of miR-151a-3p and inactivation of NOTCH2 signaling.

Dexmedetomidine Ameliorates Lung Injury Induced by Intestinal Ischemia/Reperfusion by Upregulating Cannabinoid Receptor 2, Followed by the Activation of the Phosphatidylinositol 3-Kinase/Akt Pathway.

Intestinal ischemia/reperfusion (I/R) is a clinical emergency, which often causes lung injury with high morbidity and mortality. Although dexmedetomidine has been identified to have a protective effect on lung injury caused by intestinal I/R, its specific mechanism is still elucidated. In recent years, the cannabinoid (CB2) receptor pathway has been found to be involved in I/R injury of some organs. In the current study, we investigated whether the CB2 receptor pathway contributes to the protective effect of dexmedetomidine on the intestinal I/R-induced lung injury in rats. Dexmedetomidine treatment upregulated the expression of CB2 receptor and suppressed the I/R-induced increases in lung injury scores, inflammatory cell infiltration, lung wet/dry ratio, MPO activity, MDA level, inflammatory cytokines, and caspase-3 expression while augmenting SOD activity and Bcl-2 expression, indicating attenuation of lung injury. Dexmedetomidine treatment also increased the expression of Akt. The protective effects of dexmedetomidine treatment were reversed by the CB2 receptor antagonist AM630 or the PI3K inhibitor wortmannin. And the CB2 receptor antagonist AM630 also downregulated the expression of Akt. Thus, our findings suggest that treatment with dexmedetomidine provides a protective role against lung injury caused by intestinal I/R in rats, possibly due to the upregulation of the CB2 receptor, followed by the activation of the PI3K/Akt pathway.

GTS-21 ameliorates polymicrobial sepsis-induced hepatic injury by modulating autophagy through α7nAchRs in mice.

BACKGROUND: Previous studies showed that GTS-21, a selective alpha 7 nAchR agonist, can trigger anti-inflammatory effects and improve the survival of septic animals. However, whether GTS-21 affects autophagy responses remains unclear. Here, we tested the hypothesis that GTS-21 ameliorates sepsis-induced hepatic injury by modulating autophagy in mice. METHOD: C57BL/6 male mice were randomly separated and categorized into four groups: the sham group, and CLP group subjected to caecal ligation and puncture (CLP, a model of polymicrobial sepsis). The CLP + GTS-21 group was administered GTS-21 immediately after CLP challenge. α-Bungarotoxin (an alpha 7 nAchR antagonist) was injected before CLP was performed, and then, after CLP challenge, GTS-21 was administered to α-BGT + CLP + GTS-21 group. The hepatic tissue and blood samples were harvested 6 h after the operation. RESULTS: CLP challenge increased TNF-α and IL-6 production, and hepatic enzyme alanine aminotransferase and aspartate transaminase levels. CLP also elevated the expression of hepatic LC3-II, sequestosome-1/p62, Atg7 and Atg5. The administration of GTS-21 inhibited pro-inflammatory cytokine production and hepatic enzymatic marker expression, promoted the expression of LC3-II, Atg7, Atg5, and decreased the expression of p62, which could be reversed by α-BGT treatment. CONCLUSION: Our findings suggested that α7nAchR is involved in diminishing hepatic damage by inhibiting inflammatory responses and improving autophagy in mice with polymicrobial sepsis.

The HO-1-expressing bone mesenchymal stem cells protects intestine from ischemia and reperfusion injury.

BACKGROUND: Bone mesenchymal stromal cells (BMSC) showed protective potential against intestinal ischemia. Oxygenase-1(HO-1) could alleviate oxidative stress. In the present study, we constructed HO-1-expressing BMSC and detected the effects of it on survival, intestinal injury and inflammation following intestinal ischemia and reperfusion injury (I/R). METHODS: In this experiment, eighty adult male mice were divided into Sham, I/R, I/R + BMSC, I/R + BMSC/HO-1 groups. Mice were anesthetized and intestinal I/R model were established by temporarily occluding the superior mesenteric artery for 60 min with a non-crushing clamp. Following ischemia, the clamp was removed and the intestines were allowed for reperfusion. Prior to abdominal closure, BMSC/ HO-1 (2 × 106 cells) or BMSC (2 × 106 cells) were injected into the peritoneum of I/R mice respectively. Mice were allowed to recover for 24 h and then survival rate, intestinal injury and inflammation were determined. Reactive oxygen species (ROS) was assayed by fluorescent probe. TNFα and IL-6 were assayed by ELISA. RESULTS: BMSC/HO-1 increased seven day survival rate, improved intestinal injury and down-regulated inflammation after intestinal I/R when compared with sole BMSC (p < 0.05 respectively). Multiple pro-inflammatory media were also decreased following application of BMSC/HO-1, when compared with sole BMSC (p < 0.05) respectively, suggesting that BMSC /HO-1 had a better protection to intestinal I/R than BMSC therapy. CONCLUSION: Administration of BMSC/HO-1 following intestinal I/R, significantly improved intestinal I/R by limiting intestinal damage and inflammation.

SP1, MYC, CTNNB1, CREB1, JUN genes as potential therapy targets for neuropathic pain of brain.

Neuropathic pain (NP) may cause serious brain diseases, but the genes associated with the metabolic pathway and transcript factors of NP remain unclear. This study is aimed to identify the therapy target genes for NP and to investigate the metabolic pathways and transcript factors associated with NP. The differentially expressed genes of three brain tissues (nucleus accumbens, periaqueductal gray, and prefrontal cortex) dealt with NP stimulation were analyzed. Besides, The Database for Annotation, Visualization, and Integrated Discovery and Tfacts datasets were used in the analysis of the genes related to the metabolic pathway and transcript factors of the brain. Eight genes were found to coexpress in all three tissues. A functional enrichment analysis showed that the upregulated genes were mostly enriched in pathways as inflammatory response, calcium-mediated signaling, cytokine-cytokine receptor interaction, and extracellular matrix (ECM)-receptor interaction, whereas the downregulated genes were mostly enriched in pathways as phospholipid metabolic processes, positive regulation of protein kinase B signaling, and metabolism of xenobiotics by cytochrome P450. Finally, 135 and 98 transcript factors genes were upregulated and downregulated, among which SP1, MYC, CTNNB1, CREB1, JUN were identified as the most critical genes because the number of up- and downregulated gene ranked at the top. In conclusion, the pathways of immune response and cytokine-cytokine receptor interaction were determined as the main metabolic pathways of NP affecting the brain, and SP1, MYC, CTNNB1, CREB1, JUN genes were recognized as the most enriched genes in this process, which may provide evidence for the diagnosis and treatment research of neuropathic pain.

Transduced PEP-1-Heme Oxygenase-1 Fusion Protein Attenuates Lung Injury in Septic Shock Rats.

Oxidative stress and inflammation have been identified to play a vital role in the pathogenesis of lung injury induced by septic shock. Heme oxygenase-1 (HO-1), an effective antioxidant and anti-inflammatory and antiapoptotic substance, has been used for the treatment of heart, lung, and liver diseases. Thus, we postulated that administration of exogenous HO-1 protein transduced by cell-penetrating peptide PEP-1 has a protective role against septic shock-induced lung injury. Septic shock produced by cecal ligation and puncture caused severe lung damage, manifested in the increase in the lung wet/dry ratio, oxidative stress, inflammation, and apoptosis. However, these changes were reversed by treatment with the PEP-1-HO-1 fusion protein, whereas lung injury in septic shock rats was alleviated. Furthermore, the septic shock upregulated the expression of Toll-like receptor 4 (TLR4) and transcription factor NF-κB, accompanied by the increase of lung injury. Administration of PEP-1-HO-1 fusion protein reversed septic shock-induced lung injury by downregulating the expression of TLR4 and NF-κB. Our study indicates that treatment with HO-1 protein transduced by PEP-1 confers protection against septic shock-induced lung injury by its antioxidant, anti-inflammatory, and antiapoptotic effects.

XIST accelerates neuropathic pain progression through regulation of miR-150 and ZEB1 in CCI rat models.

LncRNAs are reported to participate in neuropathic pain development. LncRNA X-inactive specific transcript (XIST) is involved in the progression of various cancers. However, the role of XIST in neuropathic pain remains unclear. In our present study, we established a chronic constriction injury (CCI) rat model and XIST was found to be greatly upregulated both in the spinal cord tissues and in the isolated microglias of CCI rats. Inhibition of XIST inhibited neuropathic pain behaviors including mechanical and thermal hyperalgesia. Moreover, decrease of XIST repressed neuroinflammation through inhibiting COX-2, tumor necrosis factor (TNF)-α and IL-6 and in CCI rats. Previously, miR-150 has been reported to restrain neuropathic pain by targeting TLR5. Currently, miR-150 was predicted to be a microRNA target of XIST, which indicated a negative correlation between miR-150 and XIST. miR-150 was remarkably decreased in CCI rats and overexpression of miR-150 can significantly suppress neuroinflammation-related cytokines. Furthermore, ZEB1 was exhibited to be a direct target of miR-150 and we found it was overexpressed in CCI rats. Silencing ZEB1 was able to inhibit neuropathic pain in vivo and downreguation of XIST decreased ZEB1, which can be reversed by miR-150 inhibitors. Taken these together, we indicated that XIST can induce neuropathic pain development in CCI rats via upregulating ZEB1 by acting as a sponge of miR-150. It was revealed that XIST/miR-150/ZEB1 axis can be provided as a therapeutic target in neuropathic pain.

Inhibition of miR-200b/miR-429 contributes to neuropathic pain development through targeting zinc finger E box binding protein-1.

Many studies have reported that microRNAs participate in neuropathic pain development. Previously, miR-200b and miR-429 are reported to be involved in various diseases. In our current study, we focused on their roles in neuropathic pain and we found that miR-200b and miR-429 were significantly decreased in chronic constriction injury (CCI) rat spinal cords and isolated microglials. miR-200b and miR-429 overexpression were able to relieve neuropathic pain through modulating PWT and PWL in CCI rats. Meanwhile, we observed that both miR-200b and miR-429 upregulation could repress neuroinflammation via inhibiting inflammatory cytokines such as IL-6, IL-1ß, and TNF-α in CCI rats. By carry out bioinformatics technology, Zinc finger E box binding protein-1 (ZEB1) was predicted as target of miR-200b, and miR-429 and dual-luciferase reporter assays confirmed the correlation between them. ZEB1 has been reported to regulate a lot of diseases. Here, we found that ZEB1 was greatly increased in CCI rats and miR-200b and miR-429 overexpression markedly suppressed ZEB1 mRNA expression in rat microglial cells. In addition, knockdown of ZEB1 can reduce neuropathic pain development and co-transfection of LV-anti-miR-200b/miR-429 reversed this phenomenon in vivo. Taken these together, our results suggested that miR-200b/miR-429 can serve as an important regulator of neuropathic pain development by targeting ZEB1.

MicroRNA-93 alleviates neuropathic pain through targeting signal transducer and activator of transcription 3.

Emerging evidence suggests that microRNAs (miRNAs) play a critical role in the pathogenesis of neuropathic pain. However, the exact role of miRNAs in regulating neuropathic pain remains largely unknown. In this study, we aimed to investigate the potential role of miR-93 in a rat model of neuropathic pain induced by chronic constriction sciatic nerve injury (CCI). We found a significant decrease of miR-93 in the spinal cord of CCI rats compared with sham rats. Overexpression of miR-93 significantly alleviated neuropathic pain development and reduced inflammatory cytokine expression, including interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, and IL-6 in CCI rats. By bioinformatic analysis and dual-luciferase reporter assay, we found that miR-93 directly targeted the 3'-untranslated region (UTR) of signal transducer and activator of transcription 3 (STAT3), an important regulator of inflammation. Overexpression of miR-93 markedly suppressed the expression of STAT3 in vitro and in vivo. Furthermore, overexpression of STAT3 significantly reversed the miR-93 overexpression-induced suppressive effects on neuropathic pain development and neuroinflammation. Taken together, our study suggests that miR-93 inhibits neuropathic pain development of CCI rats possibly through inhibiting STAT3-mediated neuroinflammation. Our findings indicate that miR-93 may serve as a novel therapeutic target for neuropathic pain intervention.

Transduced PEP-1-heme oxygenase-1 fusion protein reduces remote organ injury induced by intestinal ischemia/reperfusion.

BACKGROUND: A fusion protein composed of heme oxygenase-1 (HO-1) and cell-penetrating peptide PEP-1 has been shown to reduce local intestinal injury after intestinal ischemia/reperfusion (I/R). In this study, we investigated the effects of PEP-1-HO-1 fusion protein on remote organ injury induced by intestinal I/R in rats. MATERIAL AND METHODS: We randomly assigned 24 male Sprague-Dawley rats to 3 groups: Sham, I/R, and I/R plus PEP-1-HO-1 treatment (HO). The model of intestinal I/R was established by occluding the superior mesenteric artery for 45 min followed by 120-min reperfusion. In HO group, PEP-1-HO-1 was administered intravenously 30 min before ischemia, while animals in the Sham and I/R groups received the equal volume of physiological saline. At the end of the experiment, lung, liver, and blood samples were collected and analyzed. RESULTS: Malondialdehyde levels and histological injury scores were increased, and superoxide dismutase activities were decreased in the lung and liver tissues in the I/R group compared with the Sham group (P<0.05). Serum levels of alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor-α, interleukin-6, and lung tissue wet weight to dry weight ratio were increased in the I/R group compared with the Sham group (P<0.05). NF-κB expression in intestinal tissues was significantly higher in the I/R group than in the Sham group. These changes were significantly reversed by treatment with PEP-1-HO-1. CONCLUSIONS: This study demonstrates that administration of PEP-1-HO-1 has a protective role against lung and liver injury after intestinal I/R, attributable to the reduction of released proinflammatory cytokines regulated by NF-κB.

Transduced PEP-1-heme oxygenase-1 fusion protein protects against intestinal ischemia/reperfusion injury.

BACKGROUND: Heme oxygenase-1 (HO-1) has been shown to have antioxidant and anti-apoptotic properties. The present study transduced HO-1 protein into intestinal tissues using PEP-1, a cell-penetrating peptide, and investigated its potentiality in prevention against intestinal ischemia/reperfusion (I/R) injury. MATERIALS AND METHODS: PEP-1-HO-1 fusion protein was administered intravenously to explore the time and dose characteristics through measuring serum HO-1 levels. Twenty-four male Sprague-Dawley rats were randomly divided into three groups: sham, intestinal I/R (II/R), II/R + PEP-1-HO-1 fusion protein (HO). The model was established by occluding the superior mesenteric artery for 45 min followed by 120 min reperfusion. In HO group, PEP-1-HO-1 was administered intravenously 30 min before ischemia, whereas animals in sham and II/R groups received the equal volume of physiological saline. After the experiment, the intestines were harvested for determination of histologic injury, wet/dry ratio, enzyme activity, apoptosis, and His-probe protein (one part of PEP-1-HO-1). RESULTS: Levels of serum HO-1 were dose- and time-dependent manner after intravenous injection of PEP-1-HO-1. I/R caused deterioration of histologic characteristics and increases in histologic injury scoring, wet/dry ratio, myeloperoxidase activity, malondialdehyde, and intestinal apoptosis. These changes were also accompanied by a decrease in superoxide dismutase activity (P < 0.05). PEP-1-HO-1 treatment significantly reversed these changes (P < 0.05). Furthermore, His-probe protein expression was only detected in PEP-1-HO-1-treated animals. CONCLUSION: Treatment of PEP-1-HO-1 attenuates intestinal I/R injury, which might be attributable to its antioxidant and anti-apoptotic roles of HO-1.

Transduction of PEP-1-heme oxygenase-1 fusion protein reduces myocardial ischemia/reperfusion injury in rats.

Recent studies have uncovered that overexpression of heme oxygenase-1 (HO-1) by induction or gene transfer provides myocardial protection. In the present study, we investigated whether HO-1 protein mediated by cell-penetrating peptide PEP-1 could confer cardioprotection in a rat model of myocardial ischemia/reperfusion (I/R) injury. Male Sprague-Dawley rats were subjected to 30 minutes of ischemia by occluding the left anterior descending coronary artery and to 120 minutes of reperfusion to prepare the model of I/R. Animals were randomized to receive PEP-1-HO-1 fusion protein or saline 30 minutes before a 30-minute occlusion. I/R increased myocardial infarct size and levels of malondialdehyde, serum tumor necrosis factor alpha, and interleukin 6 and reduced myocardial superoxide dismutase activity. Administration of PEP-1-HO-1 reduced myocardial infarct size and levels of malondialdehyde, serum tumor necrosis factor alpha, and interleukin 6 and increased myocardial superoxide dismutase and HO-1 activities. His-probe protein was only detected in PEP-1-HO-1-transduced hearts. In addition, transduction of PEP-1-HO-1 markedly reduced elevated myocardial tissue nuclear factor-κB induced by I/R. The results suggested that transduction of PEP-1-HO-1 fusion protein decreased myocardial reperfusion injury, probably by attenuating the production of oxidants and proinflammatory cytokines regulated by nuclear factor-κB.

Variants of neural nitric oxide synthase in the spinal cord of neuropathic rats and their effects on nuclear factor-kappaB (NF-kappaB) activity in PC12 cells.

UNLABELLED: Neuropathic pain due to nerve injury is associated with overactivity of spinal N-methyl-D-aspartate (NMDA) receptors and nitric oxide synthases (NOS). Spinal NOS and NMDA receptors could act in a concerted manner to excite each other in nociceptive signaling. Among the 3 major NOS isoforms, neuronal NOS (nNOS) has the most functional relationship with NMDA receptors through a PDZ-PDZ (PSD-95, Dlg, ZO-1 homology) postsynapse interaction. However, some nNOS variants lack the PDZ domain, which may result in the changes in the interaction with the NMDA receptor and subsequent localization and enzymatic activity. The aim of this study was to determine which nNOS variants are expressed in the spinal cord in neuropathic rats and deduce their role in neuropathic pain by testing the effects of these kinds of nNOS on nuclear factor-kappaB (NF-kappaB) activity in PC12 cells. Western blot analysis revealed that there were at least 3 bands of nNOS (155, 135, and 125 kDa) in the spinal cord and, moreover, that nNOS at 135 kDa decreased significantly after development of neuropathic pain. 5'-RACE-PCR and Southern blots determined that the nNOS at 155 and 135 kDa corresponded to nNOSalpha and nNOSbeta, respectively, which was confirmed by RT-PCR. PC12 cells transfected with the nNOSalpha gene had no effect on NF-kappaB activity, but nNOSbeta without the PDZ domain significantly decreased that in PC12 cells. Considering the importance of spinal NF-kappaB signaling in neuropathic rat, it could be concluded that changes in spinal nNOS variants and quantity after peripheral nerve injury implicate nNOS in the generation of neuropathic pain. PERSPECTIVE: This article presents data demonstrating that nNOS variants change in the spinal cord of the rats after neuropathic pain and result in differential effects on NF-kappaB activity in PC12 cells. These changes in nNOS variants and their different characteristics may account for the spinal NO paradox role in neuropathic pain. Furthermore, these data suggest that nNOSbeta may represent a new therapeutic target for the treatment of chronic neuropathic pain.

Urinary trypsin inhibitor treatment ameliorates acute lung and liver injury resulting from sepsis in a rat model.

OBJECTIVE: To evaluate the protective effect of urinary trypsin inhibitor (UTI) on acute lung and liver injury in rat model induced by sepsis with infra-abdominal infection. METHODS: This study was performed in the University of Wuhan, Wuhan, China in May 2007. Sepsis models were made by cecal ligation and puncture (CLP) in Sprague-Dawley rats. Forty rats were randomly divided into sham, CLP, CLP/UTI I (20 u/g) and CLP/UTI II (50 u/g) groups, with 10 rats in each. All of them were sacrificed 12 hours after CLP. The mean arterial pressure (MAP), heart rate (HR), the wet-to-dry lung weight ratio (W/D) was measured and venous blood was collected for assaying tumor necrosis factor-alpha (TNF-alpha), interleukin-10 (IL-10), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactic acid. Superoxide dismutase (SOD), malondialdehyde (MDA) and expression of inducible nitric oxide synthase (iNOS) mRNA in lung and hepatic tissues were examined. RESULTS: Compared with the CLP group, MAP and HR in 50 u/g UTI treated rats was stable (p<0.01). Marked elevation levels of W/D ratio were lowered after administration of 50 u/g UTI (p<0.01). Treatment with 50 u/g UTI prevented marked elevation in MDA, ALT, AST, TNF-alpha, lactic acid levels, expression of iNOS mRNA, and elevated IL-10 and SOD activity (p<0.01). CONCLUSION: Urinary trypsin inhibitor has a protective effect against sepsis. Its action mechanisms are probably involved in the inhibition of inflammatory factor production and suppression of lipid peroxidation and iNOS mRNA expression.