Δευτέρα 18 Νοεμβρίου 2019

Emodin Attenuates Severe Acute Pancreatitis via Antioxidant and Anti-inflammatory Activity

Abstract

There is no specific drug to treat severe acute pancreatitis (SAP), which induces substantial medical and social burden. Many studies have reported the beneficial effects of emodin against SAP in vivo and in vitro. However, the underlying mechanism has been unclear. This paper described the design and implementation of anti-inflammatory and antioxidant activity of emodin. Emodin restored the pathological damage of SAP and simultaneously decreased the high levels of serum amylase, lipase, TNF-α, and IL-18 in the peripheral blood of SAP rat. Emodin reversed reactive oxygen species (ROS) in neutrophils derived from SAP rat. The levels of voltage-dependent anion channel 1 (VDAC1), NOD-like receptor protein 3 (NLRP3), caspase-1, and IL-18 were examined to analyze the change of inflammasome-related mediators between SAP and emodin treatment. These findings suggest that emodin plays its protective role on SAP against oxidative stress and inflammasome signals.

Characterization of Circular RNA and microRNA Profiles in Septic Myocardial Depression: a Lipopolysaccharide-Induced Rat Septic Shock Model

Abstract

Septic shock with heart dysfunction is common in intensive care units. However, the mechanism underlying myocardial depression is still unclear. Whether circular RNA (circRNA) or microRNA (miRNA) profiles differ between patients with and without myocardial depression is unknown. We generated a hypodynamic septic shock model induced by lipopolysaccharide (LPS) in adolescent rats. A total of 12 rats were utilized and heart tissue from each was collected. RNA sequencing was performed on left ventricular tissue. We focused on features of circRNAs and miRNAs, predicting their function by bioinformatic analysis and constructing circRNA-associated and miRNA-associated regulatory networks in heart tissue. We detected 851 circRNAs in heart samples, and 11 showed differential expression. A total of 639 annotated miRNAs and 91 novel miRNAs were explored including 78 showing differential expression between the two groups. We then constructed the most comprehensive circRNA-associated and miRNA-associated networks to explore their regulatory relationship in septic heart tissue, and demonstrated that different networks could potentially participate in and regulate the pathological process of sepsis. Furthermore, gene ontology term enrichment indicated miRNAs, and miRNA-mRNA networks could be associated with regulation and metabolic process, or influence cellular functions. The construction of regulator networks could improve the understanding of the basic molecular mechanisms underlying myocardial depression. It will be important for future investigations to ascertain the biological mechanisms present during the development of sepsis-induced myocardial depression to influence approaches to treatment.

Potential Anti-Inflammatory Effect of Escitalopram in Iodoacetamide-Induced Colitis in Depressed Ovariectomized Rats: Role of α7-nAChR

Abstract

Escitalopram, a drug of choice in the treatment of depression, was recently shown to possess an anti-inflammatory activity. The aim of the present study was to elucidate the effect of escitalopram on peripheral inflammatory cascades in iodoacetamide-induced colitis associated with depressive behavior in ovariectomized rats. Moreover, the role of α-7 nicotinic acetylcholine receptor in mediating the anti-colitic effect of escitalopram was examined using a nicotinic receptor antagonist methyllycaconitine citrate. Colitis was induced by intracolonic injection of 4% iodoacetamide in ovariectomized rats. Escitalopram (10 mg/kg/day, i.p.) was then injected for 1 week and several parameters including macroscopic (colon mass index and ulcerative area), microscopic (histopathology and scoring), and biochemical (myeloperoxidase and tumor necrosis factor-α) were determined. Colitis induction in ovariectomized rats resulted in a marked increase in colon mass index, ulcerative area, histopathological scoring, myeloperoxidase activity and tumor necrosis factor-α levels. These effects were ameliorated by escitalopram, even in the presence of methyllycaconitine indicating that α-7 nicotinic acetylcholine receptor does not mediate the anti-inflammatory effect of escitalopram. The present study revealed the beneficial effect of escitalopram in iodoacetamide induced colitis in ovariectomized rats and suggests that it may represent a new therapeutic agent for the treatment of inflammatory bowel disease, especially in patients with or at high risk of depressive behavior.

Inhibition of Fibroblast Growth Factor Receptor by AZD4547 Protects Against Inflammation in Septic Mice

Abstract

Sepsis is a life-threatening condition caused by the dysregulated host immune response to infection characterized by excessive secretion of inflammatory factors. AZD4547 is a selective inhibitor of fibroblast growth factor receptors that participates in the inflammatory response. The aim of this study was to investigate the inflammation-targeting effects and related molecular mechanisms of AZD4547 in sepsis using a cecal ligation and puncture model and RAW264.7 macrophages stimulated with lipopolysaccharide. AZD4547 improved the survival of CLP mice and exhibited a robust protective function against lung damage histologically. Pretreatment with AZD4547 significantly alleviated the expression of the pro-inflammatory factors IL-1β, IL-6, TNF-α, MMP9, and CXCL10 both in vivo and in vitro. In addition, AZD4547 suppressed the proliferative activity of macrophages in lung tissue and RAW264.7 macrophages. In addition, the LPS-induced phosphorylation of key proteins of NF-κB/MAPK/STAT3 pathways in RAW264.7 macrophages, such as p65, IκB-α, Erk1/2, JNK, and STAT3 proteins, could be inhibited by AZD4547 pretreatment. In conclusion, AZD4547 exerts a protective effect against excessive inflammatory damage in septic mice and may have the potential for use as an effective drug for the management of sepsis.

The Role of Decidual PD-1 + Treg Cells in Adverse Pregnancy Outcomes due to Toxoplasma gondii Infection

Abstract

Toxoplasma gondii infection during pregnancy can result in adverse pregnancy outcomes. Previously, we have reported that these outcomes are associated with the impaired function of decidual Treg cells; however, the detailed mechanisms involved were unclear. It has been reported that the suppressive capacity of Treg cells is dependent on PD-1 expression. The present study explored the role of decidual PD-1+ Treg cell function in adverse pregnancy outcomes due to Tgondii infection. Toxoplasma gondii–infected pregnant mice were sacrificed on gestational day 14 and their pregnancy outcomes were observed. The expression of PD-1 on decidual Treg cells and expressions of Foxp3, CTLA-4, TGF-β, and IL-10 on decidual PD-1+ and PD-1 Treg cells were determined using flow cytometry. The results showed that the expression of PD-1 on decidual Treg cells was clearly higher in the Tgondii–infected mice than in the normal mice. Meanwhile, the expressions of Foxp3, CTLA-4, TGF-β, and IL-10 on decidual PD-1+ Treg cells were higher in the infected mice than in the normal mice. The expressions were higher in decidual PD1+ Treg cells than in PD-1 Treg cells in the infected mice. However, these expressions on PD-1 Treg cells did not significantly differ between the infected and normal mice. Nonetheless, the absolute percentages of decidual PD-1+ Treg cells decreased significantly in the infected mice compared with those in the normal mice. These results suggest that Tgondii infection mainly influences the function of decidual PD-1+ Treg cells, which would result in an insufficiently immunotolerant microenvironment and consequently in adverse pregnancy outcomes.

Damage and Phenotype Change in PC12 Cells Induced by Lipopolysaccharide Can Be Inhibited by Antioxidants Through Reduced Cytoskeleton Protein Synthesis

Abstract

The present study investigated changes in cellular phenotype and oxidative stress during the inflammatory response in PC12 cells stimulated by lipopolysaccharide (LPS) and assessed the effects of minocycline, astragalus (AST), and baicalin on inflammation. PC12 cells were exposed to LPS with or without minocycline, AST, or baicalin. Cell viability was measured by a thiazolyl blue tetrazolium bromide (MTT) assay. Contrast and laser confocal microscopy were used to analyze changes in cellular phenotype and cytoskeleton synthesis. Western blotting tested the expression of α7nAChR and vimentin. Inhibitory ratio of superoxide dismutase (SOD) activity and leakage of lactate dehydrogenase (LDH) were detected to evaluate cellular oxidative stress. Results showed that LPS could attenuate PC12 cell viability in a time- and dose-dependent manner, which could be rescued by minocycline. In addition, minocycline could reverse PC12 cell phenotypic change and the synthesis of the mesenchymal cytoskeleton protein vimentin, both induced by LPS. During LPS-initiated inflammation, α7nAChR and vimentin expression were obviously inhibited by minocycline, AST, or baicalin. The inhibitory rate of SOD activity and LDH leakage in PC12 cells were increased by LPS and attenuated significantly when exposed to minocycline, AST, or baicalin. These findings suggest phenotype change, altered cytoskeleton protein synthesis, and oxidative stress are all involved in the inflammatory response in PC12 cells during which α7 nicotinic acetylcholine receptor (α7nAChR) is induced by LPS stimulation. Minocycline, AST, and baicalin have a protective effect against PC12 cell injury, acting as antioxidants and inhibitors of mesenchymal proteins.

Investigation of Extracellular Matrix Protein Expression Dynamics Using Murine Models of Systemic Inflammation

Abstract

Extracellular matrix (ECM) proteins form the structural support for migration of leukocytes and provide multiple signals to assist in their functions during inflammatory conditions. Presence of pro-inflammatory mediators in the tissues results in the remodelling of matrices which could modify the functions of extravasated leukocytes. Previous reports have shown changes in the expression of ECM proteins during local inflammatory responses. In this study, we have investigated the time- and tissue-specific expression profile of key ECM proteins in systemic inflammation using lipopolysaccharide (LPS)-induced endotoxemia and cecal ligation and puncture (CLP) mouse models. The results show that compared to naïve tissues, within 12 h following CLP surgery, a 20–30-fold increase was observed in the expression of collagen-IV (Col-IV) transcripts in the mesentery tissues with a 2.4-fold increase in the protein by 24 h. However, Western blot band intensities indicated that vimentin and fibrinogen were remarkably expressed in more quantity compared to Col-IV. Secondly, in CLP group of mice, fibrinogen showed 6–40-fold increase in mRNA level in various tissues with about 2-fold increase in the protein level compared to respective naïve tissues. Similar studies in the LPS-injected mice showed up to 2–3 fold increase in the expression of Col-IV, fibrinogen and vimentin at protein level in the lungs. In such animals, although similar pattern was observed for fibrinogen in kidney and liver tissues, the mesentery showed prominent changes in Col-IV and vimentin mRNA compared to CLP. Further, bioinformatics analysis showed multiple pathways which could be associated with vimentin, Col-IV and fibrinogen under inflammatory conditions both in human and mouse. The current study will help in better understanding of possible signalling from ECM proteins in inflammatory microenvironment and may contribute in development of cell adhesion-based therapeutics.

Role of JNK Signaling Pathway in Dexmedetomidine Post-Conditioning-Induced Reduction of the Inflammatory Response and Autophagy Effect of Focal Cerebral Ischemia Reperfusion Injury in Rats

Abstract

To investigate the effect of dexmedetomidine post-conditioning on the inflammatory response and autophagy effect of focal cerebral ischemia reperfusion injury in rats, and further to study its potential mechanisms. Water maze was conducted to evaluate spatial learning and memory ability of middle cerebral artery occlusion (MCAO) rats. TTC staining was used to observe the area of cerebral infarction. The expressions of inflammatory factors in serum were detected by ELISA. TUNEL assay, HE staining, and transmission electron microscopy were used to detect the apoptosis of neurons, neuro-cytopathic changes, and the formation of auto-phagosome in hippocampus CA1 region, respectively. The mRNA and protein expression of Beclin-1, Caspase-3, and light chain 3 (LC3) were detected by qRT-PCR and Western blot. Moreover, the activity of C-Jun N-terminal kinase (JNK) pathway was detected by Western blot. The escape latency (EL); cerebral infarction area ratio; positive apoptosis; neuron pathological changes; auto-phagosome numbers; inflammatory factor contents; mRNA and protein expressions of Beclin-1, Caspase-3 and LC3II/I; and the phosphorylation level of JNK were decreased, while the times across platform and the times stayed in the quadrant of the original platform were increased after dexmedetomidine treatment. However, the protective effect of dexmedetomidine on brain injury in MCAO rats was reversed by JNK pathway activator. Dexmedetomidine post-conditioning could improve learning and memory dysfunction caused by MCAO in rats and reduce the inflammatory response and autophagy effect. The mechanism may be related to inhibition of JNK pathway activation.

Pleural Effusion IL-33/sST2 Levels and Effects of Low and High IL-33/sST2 Levels on Human Mesothelial Cell Adhesion and Migration

Abstract

Interleukin 33 (IL-33) is an alarmin with multiple roles in immunity and cell homeostasis, highly expressed in barrier sites, acting via the suppression of tumorigenicity 2 receptor (ST2). Production of IL-33 and soluble ST2 (sST2), a decoy receptor for IL-33, has been implicated in several pulmonary diseases, but both have been scarcely investigated in pleural diseases. The aim of this study was to determine the levels of IL-33 and sST2 in transudative (TrPEs), malignant (MPEs), and parapneumonic (PPEs) pleural effusions (PEs) and investigate the effect of PE fluids from each group with low and high IL-33/sST2 levels on MeT-5A cell adhesion and migration. IL-33 and sST2 pleural fluid levels were similar among TrPEs, MPEs, and PPEs. However, a significant correlation was found between IL-33 and LDH and in sST2 levels with lymphocyte counts in TrPEs. Additionally, in MPEs the levels of IL-33 correlated with the levels of sST2 and with the red blood cell counts. Furthermore, incubation of MeT-5A cells with MPEs and PPEs bearing low or high levels of IL-33/sST2 yielded significant differential effects on MeT-5A cell adhesion and migration. In MPEs, high IL-33/sST2 levels led to increased adhesion and migration of MeT-5A cells, while in PPEs the effect was the opposite, while no effect in both cell phenotypes was determined for TrPEs. These results reveal a clinical context dependent effect of the IL-33/sST2 axis in PEs.

Immunomodulatory and Anti-Inflammatory Potential of Curcumin for the Treatment of Allergic Asthma: Effects on Expression Levels of Pro-inflammatory Cytokines and Aquaporins

Abstract

Curcumin is well known for possessing anti-inflammatory properties and for its beneficial effects in the treatment of asthma. Current study investigates the immunomodulatory and anti-inflammatory effects of curcumin using mouse model of ovalbumin-induced allergic asthma. BALB/c mice were immunized with ovalbumin on day 0 and 14 to induce allergic asthma. Animals were treated with two different doses of curcumin (20 mg/kg and 100 mg/kg) and methylprednisolone from day 21 to 28. Mice were also daily challenged intranasally with ovalbumin during treatment period, and all groups were sacrificed at day 28. Histopathological examination showed amelioration of allergic asthma in treated groups as evident by the attenuation of infiltration of inflammatory cells, goblet cell hyperplasia, alveolar thickening, and edema and vascular congestion. Curcumin significantly reduced total and differential leukocyte counts in both bronchoalveolar lavage fluid and blood. Reverse transcription polymerase chain reaction analysis showed significantly suppressed mRNA expression levels of IL-4 and IL-5 (pro-inflammatory cytokines), TNF-α, TGF-β (pro-fibrotic cytokines), eotaxin (chemokine), and heat shock protein 70 (marker of airway obstruction) in treated groups. Attenuation of these pro-inflammatory markers might have led to the suppression of airway inflammation. The expression levels of aquaporin-1 (AQP) and AQP-5 were found significantly elevated in experimental groups which might be responsible for reduction of pulmonary edema. In conclusion, curcumin significantly ameliorated allergic asthma. The anti-asthmatic effect might be attributed to the suppression of pro-inflammatory cytokines, and elevation of aquaporin expression levels, suggesting further studies and clinical trials to establish its candidature in the treatment of allergic asthma.

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