Ethyl pyruvate significantly inhibits tumour necrosis factor-α, interleukin-1β and high mobility group box 1 releasing and attenuates sodium taurocholate-induced severe acute pancreatitis associated with acute lung injury

The role of mitochondrial damage-associated molecular patterns in acute pancreatitis

Acute pancreatitis (AP) is one of the most common gastrointestinal tract diseases with significant morbidity and mortality. Current treatments remain unspecific and supportive due to the severity and clinical course of AP, which can fluctuate rapidly and unpredictably. Mitochondria, cellular power plant to produce energy, are involved in a variety of physiological or pathological activities in human body. There is a growing evidence indicating that mitochondria damage-associated molecular patterns (mtDAMPs) play an important role in pathogenesis and progression of AP. With the pro-inflammatory properties, released mtDAMPs may damage pancreatic cells by binding with receptors, activating downstream molecules and releasing inflammatory factors. This review focuses on the possible interaction between AP and mtDAMPs, which include cytochrome c (Cyt c), mitochondrial transcription factor A (TFAM), mitochondrial DNA (mtDNA), cardiolipin (CL), adenosine triphosphate (ATP) and succinate, with focus on experimental research and potential therapeutic targets in clinical practice. Preventing or diminishing the release of mtDAMPs or targeting the mtDAMPs receptors might have a role in AP progression.

Ellagic acid from whole pomegranate fruit reduces liver injury in a rat model of hepatic cholestasis

Background

Cholestasis is a health problem, both in humans and animals, which in the disease's course involves oxidative stress, inflammation, and liver fibrosis. EA has been proven to have beneficial effects on various diseases.

Aim

This study was conducted to determine the effect of EA in protecting liver damage because of cholestasis. In addition, to understand the underlying mechanism of liver damage in rats as a model animal by bile duct ligation (BDL) technique.

Methods

In this study, male adult rats were used and randomly divided into three treatment groups. S is the sham-operated group, BDL is the group that is treated with BDL and the BDL-EA group is treated with BDL and given EA by gavage at a dose of 60 mg/kg bw/day, starting on the second day after BDL and given for 21 days. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT) were evaluated using spectrophotometer; tumor necrosis factor alpha (TNF-α) and transforming growth factor beta (TGF-β1) were evaluated using sandwich ELISA and histopathological examination using HE and Massion's Trichrome staining.

Results

In this study, BDL significantly increased serum levels of AST, ALT, ALP, and hepatic GGT. In addition, BDL also increased levels of TNF-α, and TGF-β1 compared to sham-operated controls. Histological studies in the BDL group also showed that the BDL increased the degree of necro-inflammation and collagen deposition area in the liver compared to the sham-operated group. Administration of EA has been shown to significantly improve liver morpho-function of the liver. I attenuated these changes in the BDL-EA group, where all observed study variables appeared to have improved.

Conclusion

EA has been shown to reduce cholestasis that causes liver injury and improves liver enzyme profiles, and is suspected to have occurred because of its activities as an antioxidant, anti-inflammatory, and anti-fibrotic.

Role of neutrophil extracellular traps in inflammatory evolution in severe acute pancreatitis

ABSTRACT

Severe acute pancreatitis (SAP) is a life-threatening acute abdominal disease with two peaks of death: the first in the early stage, characterized by systemic inflammatory response-associated organ failure; and the second in the late stage, characterized by infectious complications. Neutrophils are the main immune cells participating in the whole process of SAP. In addition to the traditional recognition of neutrophils as the origination of chemokine and cytokine cascades or phagocytosis and degranulation of pathogens, neutrophil extracellular traps (NETs) also play an important roles in inflammatory reactions. We reviewed the role of NETs in the occurrence and development of SAP and its fatal complications, including multiple organs injury, infected pancreatic necrosis, and thrombosis. This review provides novel insights into the involvement of NETs throughout the entire process of SAP, showing that targeting NETs might be a promising strategy in SAP treatment. However, precision therapeutic options targeting NETs in different situations require further investigation.

Roles of RAGE/ROCK1 Pathway in HMGB1-Induced Early Changes in Barrier Permeability of Human Pulmonary Microvascular Endothelial Cell

Background

High mobility group box 1 (HMGB1) causes microvascular endothelial cell barrier dysfunction during acute lung injury (ALI) in sepsis, but the mechanisms have not been well understood. We studied the roles of RAGE and Rho kinase 1 (ROCK1) in HMGB1-induced human pulmonary endothelial barrier disruption.

Methods

In the present study, the recombinant human high mobility group box 1 (rhHMGB1) was used to stimulate human pulmonary microvascular endothelial cells (HPMECs). The endothelial cell (EC) barrier permeability was examined by detecting FITC-dextran flux. CCK-8 assay was used to detect cell viability under rhHMGB1 treatments. The expression of related molecules involved in RhoA/ROCK1 pathway, phosphorylation of myosin light chain (MLC), F-actin, VE-cadherin and ZO-1 of different treated groups were measured by pull-down assay, western blot and immunofluorescence. Furthermore, we studied the effects of Rho kinase inhibitor (Y-27632), ROCK1/2 siRNA, RAGE-specific blocker (FPS-ZM1) and RAGE siRNA on endothelial barrier properties to elucidate the related mechanisms.

Results

In the present study, we demonstrated that rhHMGB1 induced EC barrier hyperpermeability in a dose-dependent and time-dependent manner by measuring FITC-dextran flux, a reflection of the loss of EC barrier integrity. Moreover, rhHMGB1 induced a dose-dependent and time-dependent increases in paracellular gap formation accompanied by the development of stress fiber rearrangement and disruption of VE-cadherin and ZO-1, a phenotypic change related to increased endothelial contractility and endothelial barrier permeability. Using inhibitors and siRNAs directed against RAGE and ROCK1/2, we systematically determined that RAGE mediated the rhHMGB1-induced stress fiber reorganization via RhoA/ROCK1 signaling activation and the subsequent MLC phosphorylation in ECs.

Conclusion

HMGB1 is capable of disrupting the endothelial barrier integrity. This study demonstrates that HMGB1 activates RhoA/ROCK1 pathway via RAGE, which phosphorylates MLC inducing stress fiber formation at short time, and HMGB1/RAGE reduces AJ/TJ expression at long term independently of RhoA/ROCK1 signaling pathway.

Signal Pathways and Markers Involved in Acute Lung Injury Induced by Acute Pancreatitis

Acute pancreatitis (AP) is a common acute abdominal disease with a mortality rate of about 30%. Acute lung injury (ALI) is a common systemic complication of acute pancreatitis, with progressive hypoxemia and respiratory distress as the main manifestations, which can develop into acute respiratory distress syndrome or even multiple organ dysfunction syndrome (MODS) in severe cases, endangering human health. In the model of AP, pathophysiological process of the lung can be summarized as oxidative stress injury, inflammatory factor infiltration, and alveolar cell apoptosis. However, the intrinsic mechanisms underlying AP and how it leads to ALI are not fully understood. In this paper, we summarize recent articles related to AP leading to ALI, including the signal transduction pathways and biomarkers of AP-ALI. There are factors or pathway aggravating ALI, the JAK2-STAT3 signaling pathway, NLRP3/NF-κB pathway, mitogen-activated protein kinase, PKC pathway, neutrophil protease (NP)-LAMC2-neutrophil pathway, and the P2X7 pathway, and there are important transcription factors in the NRF2 signal transduction pathway which could give researchers better understanding of the underlying mechanisms controlling AP and ALI and lay the foundation for finally curing ALI induced by AP.

Ethyl pyruvate: A newly discovered compound against ischemia-reperfusion injury in multiple organs

Ischemia-reperfusion injury (IRI) is a process whereby an initial ischemia injury and subsequent recovery of blood flow, which leads to the propagation of an innate immune response and the changes of structural and functional of multiple organs. Therefore, IRI is considered to be a great challenge in clinical treatment such as organ transplantation or coronary angioplasty. In recent years, ethyl pyruvate (EP), a derivative of pyruvate, has received great attention because of its stability and low toxicity. Previous studies have proved that EP has various pharmacological activities, including anti-inflammation, anti-oxidative stress, anti-apoptosis, and anti-fibrosis. Compelling evidence has indicated EP plays a beneficial role in a variety of acute injury models, such as brain IRI, myocardial IRI, renal IRI, and hepatic IRI. Moreover, EP can not only effectively inhibit multiple IRI-induced pathological processes, but also improve the structural and functional lesion of tissues and organs. In this study, we review the recent progress in the research on EP and discuss their implications for a better understanding of multiple organ IRI, and the prospects of targeting the EP for therapeutic intervention.

Effects of intestinal lymphatic ligation on intestinal immunity in rats with severe acute pancreatitis

Severe acute pancreatitis (SAP) is one of the most common diseases of the gastrointestinal tract, characterized by a complicated pathogenesis, multiple organ failure, and high mortality. The primary aim of the present study was to observe the effect of intestinal lymphatic ligation on intestinal injury and modification in rats with SAP. Male Sprague‐Dawley (SD) rats were randomly divided into: (a) Saline group (SO); (b) SAP group; and (c) SAP + ligation group. We evaluated the effect of mesenteric lymphatic duct ligation on the pancreas and intestine tissue by HE. The histopathology of the pancreas in SAP + ligation rats was alleviated slightly compared with SAP rats, but aggravated in the intestine of SAP + ligation rats. Treatment of mesenteric lymphatic duct ligation resulted in an increase in the levels of tumor necrosis factor (TNF)‐α, interleukin (IL)‐1β, and myeloperoxidase compared with the small intestinal tissues of SAP rats. In addition, the expression of nucleotide‐binding oligomerization domain‐like receptors 3, apoptosis‐associated speck‐like protein containing a caspase recruitment domain (CARD) (ASC), and caspase‐1 in the intestine were higher in the SAP + ligation group. The ratio of Th1/Th2 and regulatory T cells (Tregs) in the mesenteric lymph nodes of the SAP group was lower than those in the SAP + ligation group. The present results indicated that ligation of the mesenteric lymph duct can effectively prevent intestinal inflammatory mediators entering the body through the mesenteric lymph duct, but these mediators assembled in the intestine where they induced an excessive immune response and intestinal injury during SAP.

The role and mechanism of the annexin A1 peptide Ac2-26 in rats with cardiopulmonary bypass lung injury

The main causes of lung injury after cardiopulmonary bypass (CPB) are systemic inflammatory response syndrome (SIRS) and pulmonary ischaemia‐reperfusion injury (IR‐I). SIRS and IR‐I are often initiated by a systemic inflammatory response. The present study investigated whether the annexin A1 (ANX‐A1) peptidomimetic Ac2‐26 by binding to formyl peptide receptors (FPRs) inhibit inflammatory cytokines and reduce lung injury after CPB. Male rats were randomized to the following five groups (n = 6, each): sham, exposed to pulmonary ischaemic‐reperfusion (IR‐I), IR‐I plus Ac2‐26, IR‐I plus the FPR antagonist, BoC2 (N‐tert‐butyloxycarbonyl‐Phe‐Leu‐Phe‐Leu‐Phe) and IR‐I plus Ac2‐26 and BoC2. Treatment with Ac2‐26 improved the oxygenation index, an effect blocked by BoC2. Histopathological analysis of the lung tissue revealed that the degree of lung injury was significantly less (P < 0.05) in the Ac2‐26‐treated rats compared to the other experimental groups exposed to IR‐I. Ac2‐26 treatment reduced the levels of the inflammatory cytokines TNF‐α, IL‐1β, ICAM‐1 and NF‐κB‐p65 (P < 0.05) compared to the vehicle‐treated group exposed to IR‐I. In conclusion, the annexin A1 (ANX‐A1) peptidomimetic Ac2‐26 by binding to formyl peptide receptors inhibit inflammatory cytokines and reduce ischaemic‐reperfusion lung injury after cardiopulmonary bypass.

HMGB1 as a therapeutic target in disease

High-mobility group box 1 (HMGB1) was initially recognized as a ubiquitous nuclear protein involved in maintaining the nucleosome integrity and facilitating gene transcription. HMGB1 has since been reevaluated to be a prototypical damage-associated molecular pattern (DAMP) protein, and together with its exogenous counterpart, pathogen-associated molecular pattern (PAMP), completes the body's alarmin system against disturbances in homeostasis. HMGB1 can be released into the extracellular matrix (ECM) by either granulocytes or necrotic cells to serve as a chemotaxis/cytokine during infection, endotoxemia, hypoxia, ischemia-reperfusion events, and cancer. Different isoforms of HMGB1 present with distinctive physiological functions in ECM-fully-reduced HMGB1 (all thiol) acts as the initial damage signal to recruit circulating myeloid cells, disulfide HMGB1 behaves as a cytokine to activate macrophages and neutrophils, and both signals are turned off when HMGB1 is terminally oxidized into the final sulfonate form. Targeting HMGB1 constitutes a favorable therapeutic strategy for inflammation and inflammatory diseases. Antagonists such as ethyl pyruvate inhibit HMGB1 by interfering with its cytoplasmic exportation, while others such as glycyrrhizin directly bind to HMGB1 and render it unavailable for its receptors. The fact that a mixture of different HMGB1 isoforms is present in the ECM poses a challenge in pinpointing the exact role of an individual antagonist. A more discriminative probe for HMGB1 may be necessary to advance our knowledge of HMGB1, HMGB1 antagonists, and inflammatory-related diseases.

Picroside II Improves Severe Acute Pancreatitis-Induced Intestinal Barrier Injury by Inactivating Oxidative and Inflammatory TLR4-Dependent PI3K/AKT/NF-κB Signaling and Improving Gut Microbiota

Background

Picroside II exerts anti-inflammatory and antidiarrheal effects for treating the diseases associated with oxidative injury. However, its function on pancreatitis-induced intestinal barrier injury remains unclear. Hypothesis/Purpose. We hypothesized that picroside II will have protective effects against pancreatitis-induced intestinal barrier injury by affecting oxidative and inflammatory signaling (Toll-like receptor 4- (TLR4-) dependent phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), and nuclear factor kappa B (NF-κB)). Study Design and Methods. A Sprague-Dawley (SD) rat model with severe acute pancreatitis (SAP) was induced via the injection of sodium taurocholate (4% wt/vol; 1 mL/kg). All rats were divided into 3 groups: sham (CG), SAP-induced intestinal barrier injury (MG), and picroside II (PG) groups. Intestinal barrier injury was assessed by scanning electron microscopy (SEM), hematoxylin and eosin staining, and pathological scores. We measured the levels of pancreatitis biomarkers (amylase and lipase), oxidative and inflammatory signaling (TLR4-dependent PI3K/AKT/NF-κB), oxidative stress marker (superoxidase dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx), and malondialdehyde), and inflammatory markers (tumor necrosis factor α (TNFα), interleukin- (IL-) 1, IL-6, and IL-10) in serum and/or gut tissues. Gut microbiota composition in feces was measured by using 16S rRNA sequencing.

Results

SEM showed that intestinal barrier injury was caused with the loss of intestinal villi and mitochondria destruction, and pathological scores were increased in the MG group. The levels of amylase, lipase, malondialdehyde, TNFα, IL-1, IL-6, TLR4, PI3K, AKT, and NF-κB were increased, and the levels of SOD, GPx, CAT, and IL-10 was reduced in the MG group when compared with CG group (P < 0.05). Picroside II treatment inhibited the symptoms in the MG group and showed antioxidant and anti-inflammatory activities. The serum levels of picroside II had strong correlation with the levels of inflammatory and oxidative stress biomarkers (P < 0.05). Picroside II treatment increased the proportion of Lactobacillus and Prevotella and decreased the proportion of Helicobacter and Escherichia_Shigella in the model.

Conclusions

Picroside II improved the SAP-induced intestinal barrier injury in the rat model by inactivating oxidant and inflammatory signaling and improving gut microbiota.

Protective Effect of Alprostadil on Acute Pancreatitis in Rats via Inhibiting Janus Kinase 2 (JAK2)/STAT3 Signal Transduction Pathway

Background

Alprostadil can inhibit inflammation and reduce inflammation-related injury in many inflammatory diseases. However, the anti-inflammatory effect of alprostadil in decreasing acute pancreatitis (AP) injury remains unknow. This study aimed to investigate the possible protective effects and mechanism of alprostadil against AP in rats.

Material/Methods

Forty healthy Sprague-Dawley rats were randomly divided into a control group, an AP group, an AP-alprostadil group, an AP-AG490 group, and an AP-(alprostadil+AG490) group. An animal model of acute pancreatitis was established. The pathological changes of the pancreases in each group were observed. We assessed levels of malondialdehyde (MDA), superoxide dismutase (SOD), and myeloperoxidase (MPO), as well as serum IL-1β, IL-6, IL-10, and TNF-α. TUNEL assay was used to detect apoptosis of pancreatic cells. The proteins p-Jak2 and p-Stat3 were investigated by Western blot.

Results

Compared with the control group, pancreatic pathological score, pancreatic apoptosis, MDA, MPO, serum IL-1β, IL-6, and TNF-α levels were significantly higher in the AP group, and SOD levels were significantly decreased. Compared with the AP group, after treatment with alprostadil, AG490, and alprostadil+AG490, respectively, the pancreatic pathological score, apoptosis, MDA, MPO, serum IL-1β, IL-6, and TNF-α were significantly decreased in AP rats, while SOD levels were significantly increased. The protein levels of p-JAK2 and p-STAT3 were significantly upregulated in the AP group compared with the control group, and the protein levels of p-JAK2 and p-STAT3 after treatment with alprostadil, AG490, and alprostadil+AG490 were significantly decreased, and the effect of alprostadil+AG490 was the strongest.

Conclusions

Alprostadil can reduce pancreatic tissue damage, delay pancreatic cell apoptosis, and reduce inflammation and anti-oxidative stress by inhibiting the JAK2/STAT3 signal pathway, thus protecting the pancreas.

Efficacy of blood purification for severe pancreatitis and acute respiratory distress syndrome

BACKGROUND

This study will assess the efficacy and safety of blood purification (BP) for severe pancreatitis (SP) and acute respiratory distress syndrome (ARDS).

METHODS

We will search the following electronic databases of Ovid MEDLINE, EMBASE, Web of Science, Cochrane Library, Scopus, Cumulative Index to Nursing and Allied Health Literature, the Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and WANGFANG from inception to the present without language restriction. A systematic review and data synthesis will be carried out of randomized controlled trials of BP for the treatment of patients with SP and ARDS. RevMan 5.3 software will be used for statistical analysis.

RESULTS

This systematic review will evaluate the efficacy and safety of BP for the treatment of patients with SP and ARDS. The primary outcome includes respiratory indexes, blood biochemical and inflammatory factors. The secondary outcomes consist of complications, sepsis, abdominal hemorrhage, renal failure, length of hospital stay, and mortality.

CONCLUSION

This study will provide up-to-date evidence of BP for the treatment of patients with SP and ARDS.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019139467.

Ethyl pyruvate and analogs as potential treatments for acute pancreatitis: A review of in vitro and in vivo studies

Ethyl pyruvate (EP) has been shown to improve outcomes from multiple organ dysfunction syndrome (MODS) in experimental animal models of critical illness. This review aimed to summarise in vitro and in vivo effects of EP analogs on acute pancreatitis (AP) with the objective of proposing medicinal chemistry modifications of EP for future research. In vitro studies showed that both sodium pyruvate and EP significantly reduced pancreatic acinar necrotic cell death pathway activation induced by multiple pancreatic toxins. In vivo studies using different murine AP models showed that EP (usually at a dose of 40 mg/kg every 6 h) consistently reduced pain, markers of pancreatic injury, systemic inflammation and MODS. There was also a significant increase in survival rate, even when EP was administered 12 h after disease induction (compared with untreated groups or those treated with Ringer's lactate solution). Experimental studies suggest that EP and analogs are promising drug candidates for treating AP. EP or analogs can undergo medicinal chemistry modifications to improve its stability and deliverability. EP or analogs could be evaluated as a supplement to intravenous fluid therapy in AP.

Icariin and icaritin ameliorated hippocampus neuroinflammation via inhibiting HMGB1-related pro-inflammatory signals in lipopolysaccharide-induced inflammation model in C57BL/6 J mice

Inflammation is a defensive response of the body and is at the center of many diseases' process like depression. High mobility group protein box 1 (HMGB1), has been proved to function as a pro-inflammatory cytokine. We aim to explore the role of HMGB1 played in the neuroinflammation here. In this study, we used LPS to induce an acute inflammatory response, and to measure the anti-neuroinflammation effect of icariin (ICA) and icaritin (ICT). We found that LPS could increase the expression of HMGB1 in serum and hippocampus, along with a high expression of HMGB1 in the cytoplasm and a high expression of RAGE, which could be rescued by ICA and ICT, and ethyl pyruvate (EP) pretreatment showed similar effects here. We speculated that the translocation of HMGB1 from the nucleus to the cytoplasm played an important role in neuroinflammatory process, and HMGB1-RAGE signal was involved in this process. Furthermore, we found that ICA and ICT treatment activated TLR4-XBP1s related NF-κB signal, which we thought was relevant with the neuroprotective effect of ICA and ICT. However, EP pretreatment suppressed TLR4-XBP1s- endoplasmic reticulum stress related NF-κB signal to anti-inflammatory response, which was almost absolutely opposite with ICA and ICT treatment. We speculated that it might be caused by the duration of inflammation. We supposed that ICA and ICT could ameliorate neuroinflammation in hippocampus via suppressing HMGB1-RAGE signaling and might show a neuroprotective effect via activating TLR4-XBP1s related NF-κB signal at the same time, making it possible to act as an anti-neuroinflammatory drugs.

Gamma-enolase predicts lung damage in severe acute pancreatitis-induced acute lung injury

Severe acute pancreatitis (SAP) associated acute lung injury (ALI) accounts for about 70% mortality of SAP patients. However, there are no precise biomarkers for the disease currently. Herein, we evaluated the potential of gamma-enolase (ENO2), against its universal isoform alpha-enolase (ENO1), as a marker of SAP-ALI in a rat model. Firstly, 16 male Sprague-Dawley rats were randomly divided into two groups, Sham (n = 8) and SAP-ALI (n = 8), for pancreatitis induction. Ultra-structure examination by electron microscopy and HE staining were used for lung injury assessment. Lung tissue expressions of alpha-enolase and gamma-enolase were evaluated by qRT-PCR and immunohistochemistry. In a prospective validation experiment, 28 rats were used: sham (n = 8), SAP-ALI at 3 h (3 h, n = 10), and SAP-ALI at 24 h (24 h, n = 10). Lung tissue damage, tissue expression and circulating alpha-enolase and gamma-enolase levels were evaluated. Elevated serum levels of α-amylase and TNF-α were observed in SAP rats but not in sham-operated rats. Histological examination of pancreatic and lung tissues indicated marked damage in SAP rats. While alpha-enolase was universally expressed, gamma-enolase was expressed only in damaged lung tissues. Gamma-enolase was detected in lung tissues, BALF, and serum as early as 3 h post-surgery when physical pathological damage was not apparent. Unlike alpha-enolase, secreted and/or circulating gamma-enolase level progressively increased, especially in serum, as lung damage progressed. Thus, gamma-enolase may signal and correlate lung tissue damage well before obvious physical pathological tissue damage and might be a candidate diagnostic and/or prognostic marker.

Is MicroRNA-127 a Novel Biomarker for Acute Pancreatitis with Lung Injury?

Background and Aims

The aim of this study was to determine the expression of microRNA-127 (miR-127) in both rat models and patients of acute pancreatitis (AP) with lung injury (LI).

Methods

Rats were administrated with retrograde cholangiopancreatography injection of 0.5% or 3.5% sodium taurocholate to induce AP with mild or severe LI and were sacrificed at 6, 12, and 24 h. Rats from the control group received a laparotomy only. Plasma from a prospective cohort of AP patients was collected. The levels of miR-127 in the tissues and plasma were detected using quantitative reverse transcription-polymerase chain reaction (qRT-PCR).

Results

The upregulation of miR-127 in the lungs of rats was detected in the groups of AP with severe LI at 6 h and 24 h, whereas it was scarcely detectable in plasma. In the pilot study that included 18 AP patients and 5 healthy volunteers, the plasma miR-127 level was significantly downregulated in AP patients with respiratory failure compared with the healthy volunteers (P = 0.014) and those without respiratory failure (P = 0.043).

Conclusion

miR-127 might serve as a potential marker for the identification of AP with LI.

Ethyl pyruvate reverses development of Pseudomonas aeruginosa pneumonia during sepsis-induced immunosuppression

Sepsis is characterized by an innate immune response and the following immune dysfunction which can increase the emergence of secondary infections. Ethyl pyruvate (EP) has multiple immunoregulation functions in several serious illnesses, such as burn injury, severe sepsis and acute respiratory syndrome. However, little data was shown the effect of EP administration on immunosuppression post-CLP and the following secondary infection. The cecal ligation and puncture (CLP) followed by the induction of Pseudomonas aeruginosa (PA) was used as a clinically relevant two-hit model of sepsis. We assessed the survival rate, lung damage and lung bacterial clearance in vehicle or EP treatment group to demonstrate the lung response to Pseudomonas aeruginosa of septic mice. Then cytokines including lung IL-6, IL-1β, IL-10 and plasma HMGB1, apoptosis of splenic immune cells and Foxp3 level on regulatory T cells (Tregs) were studied to demonstrate the mechanisms of EP administration on two-hit mice. We found that the susceptibility of septic mice to Secondary Pseudomonas aeruginosa pneumonia could be down-regulated by ethyl pyruvate treatment and the protective effects of EP may via decreasing lung IL-10 and plasma HMGB1 expression, inhibiting the function of Tregs and relieving the apoptosis of splenic immune cells. The "immune paralysis" post-sepsis still remains a rigorous challenge for curing sepsis, our study may aid in the development of new therapeutic strategies to this problem.

Emodin alleviates severe acute pancreatitis-associated acute lung injury by decreasing pre-B-cell colony-enhancing factor expression and promoting polymorphonuclear neutrophil apoptosis

The present study aimed to evaluate the protective effects of emodin on severe acute pancreatitis (SAP)‑associated acute lung injury (ALI), and investigated the possible mechanism involved. SAP was induced in Sprague‑Dawley rats by retrograde infusion of 5% sodium taurocholate (1 ml/kg), after which, rats were divided into various groups and were administered emodin, FK866 [a competitive inhibitor of pre‑B‑cell colony‑enhancing factor (PBEF)] or dexamethasone (DEX). DEX was used as a positive control. Subsequently, PBEF expression was detected in polymorphonuclear neutrophils (PMNs) isolated from rat peripheral blood by reverse transcription‑quantitative polymerase chain reaction and western blotting. In addition, histological alterations, apoptosis in lung/pancreatic tissues, apoptosis of peripheral blood PMNs and alterations in the expression of apoptosis‑associated proteins were examined by hematoxylin and eosin staining, terminal deoxynucleotidyl‑transferase‑mediated dUTP nick end labeling assay, Annexin V/propidium iodide (PI) assay and western blotting, respectively. Serum amylase activity and wet/dry (W/D) weight ratios were also measured. An in vitro study was also conducted, in which PMNs were obtained from normal Sprague‑Dawley rats and were incubated with emodin, FK866 or DEX in the presence of lipopolysaccharide (LPS). Apoptosis of PMNs and the expression levels of apoptosis‑associated proteins were examined in cultured PMNs in vitro by Annexin V/PI assay and western blotting, respectively. The results demonstrated that emodin, FK866 and DEX significantly downregulated PBEF expression in peripheral blood PMNs. In addition, emodin, FK866 and DEX reduced serum amylase activity, decreased lung and pancreas W/D weight ratios, alleviated lung and pancreatic injuries, and promoted PMN apoptosis by regulating the expression of apoptosis‑associated proteins: Fas, Fas ligand, B‑cell lymphoma (Bcl)‑2‑associated X protein, cleaved caspase‑3 and Bcl‑extra‑large. In addition, the in vitro study demonstrated that emodin, FK866 and DEX significantly reversed the LPS‑induced decrease of apoptosis in PMNs by regulating the expression of apoptosis‑associated proteins. In conclusion, the present study demonstrated that emodin may protect against SAP‑associated ALI by decreasing PBEF expression, and promoting PMN apoptosis via the mitochondrial and death receptor apoptotic pathways.

Picroside II Shows Protective Functions for Severe Acute Pancreatitis in Rats by Preventing NF-κB-Dependent Autophagy

Picroside II, from the herb Picrorhiza scrophulariiflora Pennell, has antioxidant and anti-inflammatory activities. However, its function on severe acute pancreatitis (SAP) and molecular mechanism remains unknown. The effects of picroside II on the SAP induced by cerulean were investigated. SAP rats were treated with picroside II (25 mg/kg). The severity of SAP was evaluated by using biochemical and histological analyses. Pancreatic cancer cell PANC-1 was transfected with ptfLC3 (an indicator of autophagic activity), pcDNA3.1-NF-κB (nuclear factor kappa B), and pTZU6+1-NF-κB-shRNA and then treated with picroside II. Relative molecules related with NF-κB-dependent autophagy were detected by using Western blot. Autophagic activities were observed by phase-contrast and fluorescent microscopes. Acetylated LC3 was detected by immunoprecipitation. The results showed that picroside II treatment reduced the level of ALT, AST, NF-κB, IL-1β, IL-6, TNF-α, and SIRT1 (NAD⁺-dependent deacetylase) and increased the level of SOD and GSH. The autophagic activity was reduced when NF-κB was silenced, and the levels of TNF-α and SIRT1 were reduced. In contrast, the overexpression of NF-κB increased autophagic activity and the level of TNF-α, which activated SIRT1. SIRT1 deacetylated LC3 and increased autophagic activities. Picroside II ameliorates SAP by improving antioxidant and anti-inflammtory activities of SAP models via NF-κB-dependent autophagy.

Ethyl pyruvate alleviates radiation-induced lung injury in mice

OBJECTIVE

Radiation-induced lung injury (RILI) is a common complication of thoracic cancer radiation therapy. Ethyl pyruvate (EP) was reported to have an ameliorating effect on a variety of systemic inflammation reactions, including acute lung injury. However, the protective effect of EP on RILI has not been explored.

MATERIALS/METHODS

RILI was induced by a single thoracic irradiation of 16Gy X-rays in C57BL/6 mice. Mice were divided into four groups: control, radiation, 100mg/kg EP, and 200mg/kg dexamethasone. Inflammation and fibrosis grade of lung tissue were scored by H&E and Masson's trichrome staining. Cytokines include IL-1β, IL-6, TNF-α, GM-CSF, M-CSF, TGF-β1, and HMGB1 were measured after irradiation. Colony formation assay was performed to determine the protective effect of EP in RAW264.7 and HBE cells. The effect of EP on HMGB1 was also explored in vitro.

RESULT

The cytoplasm of bronchial epithelium cells in mice was positive-stained of HMGB1 accompanying with an increase of HMGB1, IL-6, IL-1β, GM-CSF, M-CSF, TNF-α, and TGF-β1 after irradiation. EP prescription significantly reduced pulmonary inflammation infiltration of RILI, along with a decrease of HMGB1, IL-6, IL-1β, and GM-CSF at 4 weeks after irradiation. Furthermore, EP decreased radiation-induced collagen deposition at 20 weeks after irradiation. Pro-fibrotic cytokines including TGF-β1 and HMGB1 in irradiated lung tissue and plasma obviously decreased in EP administration group in the later stage. In vitro, EP administration protected HBE cells from radiation injury. EP also rescued radiation-induced release but not translocation of HMGB1 in RAW264.7 and HBE cells.

CONCLUSION

EP treatment ameliorates RILI, including radiation-induced fibrosis in mice. The inhibition of production and release of pro-inflammatory or fibrotic cytokines, especially HMGB1, may partly attribute to its attenuating RILI effect.

Ethyl pyruvate is a novel anti-inflammatory agent to treat multiple inflammatory organ injuries

Ethyl pyruvate (EP) is a simple derivative of pyruvic acid, which is an important endogenous metabolite that can scavenge reactive oxygen species (ROS). Treatment with EP is able to ameliorate systemic inflammation and multiple organ dysfunctions in multiple animal models, such as acute pancreatitis, alcoholic liver injury, acute respiratory distress syndrome (ARDS), acute viral myocarditis, acute kidney injury and sepsis. Recent studies have demonstrated that prolonged treatment with EP can ameliorate experimental ulcerative colitis and slow multiple tumor growth. It has become evident that EP has pharmacological anti-inflammatory effect to inhibit multiple early inflammatory cytokines and the late inflammatory cytokine HMGB1 release, and the anti-tumor activity is likely associated with its anti-inflammatory effect. EP has been tested in human volunteers and in a clinical trial of patients undergoing cardiac surgery in USA and shown to be safe at clinical relevant doses, even though EP fails to improve outcome of the heart surgery, EP is still a promising agent to treat patients with multiple inflammatory organ injuries and the other clinical trials are on the way. This review focuses on how EP is able to ameliorate multiple organ injuries and summarize recently published EP investigations.

Graphical Abstract

Role of HMGB1 translocation to neuronal nucleus in rat model with septic brain injury

High-mobility Group Box-1 (HMGB1) is a central late proinflammatory cytokine that triggers the inflammatory response during sepsis. However, whether HMGB1 is involved in the pathogenesis of septic brain damage is unknown. In this study, we investigated the role of HMGB1 in regulating brain injury in a rat model of sepsis. Wistar rats were subjected to cecal ligation and puncture (CLP) to induce septic brain injury. Hematoxylin and eosin staining was used to detect pathological changes in the cortex. The cellular localization of HMGB1 was determined using immunostaining. Cortical levels of HMGB1, its receptor for advanced glycation end-products (RAGE), and downstream effecter, nuclear factor kappa-B (NF-κB) subunit p65, were detected via western blot.HMGB1was increased in the cytoplasm via translocation from the nucleus predominantly in neurons. Moreover, RAGE and NF-κB p65 were upregulated after septic brain injury. Ethyl pyruvate, an inhibitor of HMGB1, down-regulated the expression of RAGE and NF-κB p65via inhibiting HMGB1 expression in the cytoplasm. Collectively, our findings suggest that HMGB1 and its signaling transduction have critical roles in the pathogenesis of septic brain injury. HMGB1 inhibition might be a potential new therapeutic target for septic brain injury.

Ethyl pyruvate attenuated coxsackievirus B3-induced acute viral myocarditis by suppression of HMGB1/RAGE/NF-ΚB pathway

Inflammation plays important roles in the pathogenesis of coxsackievirus B3 (CVB3)-induced acute viral myocarditis (AVMC). Ethyl pyruvate (EP) has been shown to be an anti-inflammatory agent. High mobility group box 1 (HMGB1)/receptor for advanced glycation end product (RAGE)/nuclear factor (NF)-ΚB pathway has close relation with inflammatory responses. Here, we investigated the effects of EP on CVB3-induced AVMC and potential mechanisms. The mice with AVMC were treated with EP (40 or 80 mg/kg/day) from day 5 to day 7 post-infection. EP significantly decreased the mortality of mice with AVMC. H&E staining and immunohistochemistry for HMGB1 demonstrated less inflammatory lesions and fewer abnormal location of HMGB1 in the hearts of AVMC mice receiving EP. Immuoblot showed that EP significantly inhibited the levels of HMGB1, RAGE, phospho(p)-NF-ΚB and p-I-ΚBα, and raised I-ΚBα expression in the hearts of AVMC mice. Furthermore, real-time PCR and Elisa displayed decreased levels of HMGB1, TNF-α, IL-1β, IL-17 and increased levels of IL-10 in the hearts and serum of AVMC mice treated with EP. Our findings suggest that EP protects against CVB3-induced AVMC that is associated with inhibition of HMGB1/RAGE/NF-ΚB pathway.

Dihydro-Resveratrol Ameliorates Lung Injury in Rats with Cerulein-Induced Acute Pancreatitis

Acute pancreatitis is an inflammatory process originated in the pancreas; however, it often leads to systemic complications that affect distant organs. Acute respiratory distress syndrome is indeed the predominant cause of death in patients with severe acute pancreatitis. In this study, we aimed to delineate the ameliorative effect of dihydro-resveratrol, a prominent analog of trans-resveratrol, against acute pancreatitis-associated lung injury and the underlying molecular actions. Acute pancreatitis was induced in rats with repetitive injections of cerulein (50 µg/kg/h) and a shot of lipopolysaccharide (7.5 mg/kg). By means of histological examination and biochemical assays, the severity of lung injury was assessed in the aspects of tissue damages, myeloperoxidase activity, and levels of pro-inflammatory cytokines. When treated with dihydro-resveratrol, pulmonary architectural distortion, hemorrhage, interstitial edema, and alveolar thickening were significantly reduced in rats with acute pancreatitis. In addition, the production of pro-inflammatory cytokines and the activity of myeloperoxidase in pulmonary tissues were notably repressed. Importantly, nuclear factor-kappaB (NF-κB) activation was attenuated. This study is the first to report the oral administration of dihydro-resveratrol ameliorated acute pancreatitis-associated lung injury via an inhibitory modulation of pro-inflammatory response, which was associated with a suppression of the NF-κB signaling pathway.

Ethyl pyruvate attenuates murine allergic rhinitis partly by decreasing high mobility group box 1 release

High-mobility group box 1 (HMGB1) protein, a pro-inflammatory DNA-binding protein, meditates inflammatory responses through Toll-like receptor-4 signals and amplifies allergic inflammation by interacting with the receptor for advanced glycation end products. Previous studies have shown that HMGB1 is elevated in the nasal lavage fluids (NLF) of children suffering from allergic rhinitis (AR) and is associated with the severity of this disease. Furthermore, HMGB1 has been implicated in the pathogenesis of lower airway allergic diseases, such as asthma. Ethyl pyruvate (EP) has proven to be an effective anti-inflammatory agent for numerous airway diseases. Moreover, EP can inhibit the secretion of HMGB1. However, few studies have examined the effect of EP on AR. We hypothesized that HMGB1 plays an important role in the pathogenesis of AR and studied it using an AR mouse model. Forty BALB/c mice were divided into four groups: the control group, AR group, 50 mg/kg EP group, and 100 mg/kg EP group. The mice in the AR and EP administration groups received ovalbumin (OVA) sensitization and challenge, whereas those in the control group were given sterile saline instead of OVA. The mice in the EP administration group were given an intraperitoneal injection of EP 30 min before each OVA treatment. The number of nasal rubbings and sneezes of each mouse was counted after final treatment. Hematoxylin-eosin staining, AB-PAS staining, interleukin-4 and 13 in NLF, IgE, and the protein expression of HMGB1 were measured. Various features of the allergic inflammation after OVA exposure, including airway eosinophilia, Th-2 cytokine production, total IgE, and goblet cell hyperplasia were significantly inhibited by treatment with EP and the expression and release of HMGB1 were reduced after EP administration in a dose-dependent manner. These results indicate that HMGB1 is a potential therapeutic target of AR and that EP attenuates AR by decreasing HMGB1 expression.

Baicalein protect pancreatic injury in rats with severe acute pancreatitis by inhibiting pro-inflammatory cytokines expression

BACKGROUND/AIM

Inflammatory cytokines is a key point in the development of pathogenesis of SAP. Inflammatory mediators TNF-α and IL-6 are up-regulated in serum of patients with SAP and become good discriminators of SAP severity.

MATERIALS AND METHODS

In this study, we investigated the treatment effectiveness of Baicalein on SAP rat model. Baicalein was intravenously injected immediately after SAP induction in rats. The mortality, histopathology score, ascites fluid volume, and pro-inflammatory cytokine production were evaluated at 12 h after SAP induction.

RESULTS

Baicalein decreased the pancreatic histopathology score, reduced ascites fluid production, protected against pancreatic injury, and improved survival in rats with SAP. The serum IL-6 and TNF-α concentrations were also down-regulated by Baicalein.

CONCLUSION

Baicalein demonstrated a well curative capability on rats with SAP. The mechanism may be alleviateing pancreatic injury and inhibiting pro-inflammatory cytokines expression.

HMGB1 may act via RAGE to promote angiogenesis in the later phase after intracerebral hemorrhage

Following intracerebral hemorrhage (ICH), high-mobility group box 1 protein (HMGB1) may promote vascular remodeling. Whether HMGB1 supports angiogenesis after ICH is unclear, as are the receptors and downstream signaling pathway(s) involved. We used the rat model of collagenase-induced ICH to determine whether HMGB1 acts via the receptor for advanced glycation end-products (RAGE) to upregulate vascular endothelial growth factor (VEGF), a potent mitogen of endothelial cells and key regulator of normal and abnormal angiogenesis in the late phase of injury. At 3d after ICH induction, rats were treated with saline, ethyl pyruvate (EP) or N-benzyl-4-chloro-N-cyclohexylbenzamide (FPS-ZM1). ICH induced the movement of HMGB1 from the nucleus into the cytoplasm. Levels of HMGB1 and RAGE in the ipsilateral striatum increased within a few days of induction and continued to rise for 7-14d afterward. By 14d after induction, levels of VEGF and vessel density were higher than in the Sham group. Administering EP 3 days after ICH induction prevented much of the stroke-induced increases in vessel density and in expression of HMGB1, RAGE, and VEGF. Administering FPS-ZM1 after ICH blocked much of the stroke-induced increases in vessel density and VEGF expression. Our results suggest that after ICH, HMGB1 may upregulate VEGF in the ipsilateral striatum predominantly via RAGE. Hence, targeting the HMGB1/RAGE signaling pathway may help reduce inappropriate angiogenesis after ICH.

High-mobility group box 1 protein and its role in severe acute pancreatitis

The high mobility group box 1 (HMGB1), which belongs to the subfamily of HMG-1/-2, is a highly conserved single peptide chain consisting of 215 amino acid residues with a molecular weight of approximately 24894 Da. HMGB1 is a ubiquitous nuclear protein in mammals and plays a vital role in inflammatory diseases. Acute pancreatitis is one of the most common causes of acute abdominal pain with a poor prognosis. Acute pancreatitis is an acute inflammatory process of the pancreas (duration of less than six months), for which the severe form is called severe acute pancreatitis (SAP). More and more studies have shown that HMGB1 has a bidirectional effect in the pathogenesis of SAP. Extracellular HMGB1 can aggravate the pancreatic inflammatory process, whereas intracellular HMGB1 has a protective effect against pancreatitis. The mechanism of HMGB1 is multiple, mainly through the nuclear factor-κB pathway. Receptors for advanced glycation end-products and toll-like receptors (TLR), especially TLR-2 and TLR-4, are two major types of receptors mediating the inflammatory process triggered by HMGB1 and may be also the main mediators in the pathogenesis of SAP. HMGB1 inhibitors, such as ethyl pyruvate, pyrrolidine dithiocarbamate and Scolopendra subspinipes mutilans, can decrease the level of extracellular HMGB1 and are the promising targets in the treatment of SAP.

HMGB1 in health and disease

Complex genetic and physiological variations as well as environmental factors that drive emergence of chromosomal instability, development of unscheduled cell death, skewed differentiation, and altered metabolism are central to the pathogenesis of human diseases and disorders. Understanding the molecular bases for these processes is important for the development of new diagnostic biomarkers, and for identifying new therapeutic targets. In 1973, a group of non-histone nuclear proteins with high electrophoretic mobility was discovered and termed high-mobility group (HMG) proteins. The HMG proteins include three superfamilies termed HMGB, HMGN, and HMGA. High-mobility group box 1 (HMGB1), the most abundant and well-studied HMG protein, senses and coordinates the cellular stress response and plays a critical role not only inside of the cell as a DNA chaperone, chromosome guardian, autophagy sustainer, and protector from apoptotic cell death, but also outside the cell as the prototypic damage associated molecular pattern molecule (DAMP). This DAMP, in conjunction with other factors, thus has cytokine, chemokine, and growth factor activity, orchestrating the inflammatory and immune response. All of these characteristics make HMGB1 a critical molecular target in multiple human diseases including infectious diseases, ischemia, immune disorders, neurodegenerative diseases, metabolic disorders, and cancer. Indeed, a number of emergent strategies have been used to inhibit HMGB1 expression, release, and activity in vitro and in vivo. These include antibodies, peptide inhibitors, RNAi, anti-coagulants, endogenous hormones, various chemical compounds, HMGB1-receptor and signaling pathway inhibition, artificial DNAs, physical strategies including vagus nerve stimulation and other surgical approaches. Future work further investigating the details of HMGB1 localization, structure, post-translational modification, and identification of additional partners will undoubtedly uncover additional secrets regarding HMGB1's multiple functions.

Caspase-1 inhibition alleviates acute renal injury in rats with severe acute pancreatitis

AIM: To assess the effect of inhibition of caspase-1 on acute renal injury in rats with severe acute pancreatitis (SAP).

METHODS: Forty-two Sprague-Dawley rats were randomly divided into three groups: healthy controls (HC, n = 6), SAP rats treated with saline (SAP-S, n = 18), or SAP rats treated with a caspase-1/interleukin (IL)-1β-converting-enzyme (ICE) inhibitor (SAP-I-ICE, n = 18). SAP was induced by retrograde infusion of 5% sodium taurocholate into the bile-pancreatic duct. HC rats were subjected to identical treatment and surgical procedures without sodium taurocholate. Rats received an intraperitoneal injection of isotonic saline (SAP-S) or the inhibitor (SAP-ICE-I) at 2 and 12 h after induction of acute pancreatitis. Surviving rats were sacrificed at different time points after SAP induction; all samples were obtained and stored for subsequent analyses. The levels of blood urea nitrogen (BUN) and creatinine (Cr) were measured using automatic methods, and serum IL-1β concentrations were measured by an enzyme-linked immunosorbent assay. Intrarenal expression of IL-1β, IL-18 and caspase-1 mRNAs was detected by RT-PCR. IL-1β protein expression and the pathologic changes in kidney tissues were observed by microscopy after immunohistochemical or hematoxylin and eosin staining, respectively.

RESULTS: The serum levels of BUN and Cr in the SAP-S group were 12.48 ± 2.30 mmol/L and 82.83 ± 13.89 μmol/L at 6 h, 23.53 ± 2.58 mmol/L and 123.67 ± 17.67 μmol/L at 12 h, and 23.60 ± 3.33 mmol/L and 125.33 ± 21.09 μmol/L at 18 h, respectively. All were significantly increased compared to HC rats (P < 0.01 for all). Levels in SAP-ICE-I rats were significantly decreased compared to SAP-S rats both at 12 and 18 h (P < 0.01 for all). Serum IL-1β levels in the SAP-S group were 276.77 ± 44.92 pg/mL at 6 h, 308.99 ± 34.95 pg/mL at 12 h, and 311.60 ± 46.51 pg/mL at 18 h; all significantly higher than those in the HC and SAP-ICE-I groups (P < 0.01 for all). Intrarenal expression of IL-1β mRNA was weak in HC rats, but increased significantly in SAP-S rats (P < 0.01). ICE inhibition significantly decreased the expression of IL-1β and IL-18 mRNAs (P < 0.05 for all vs SAP-S), whereas caspase-1 mRNA expression was not significantly different. Weak IL-1β immunostaining was observed in HC animals, and marked staining was found in the SAP-S group mainly in renal tubular epithelial cells. IL-1β immunostaining was significantly descended in SAP-ICE-I rats compared to SAP-S rats (P < 0.05). Caspase-1 inhibition had no effect on the severity of kidney tissue destruction.

CONCLUSION: The expression of caspase-1-activated cytokines IL-1β and IL-18 plays a pivotal role in acute renal injury in rats with experimental SAP. Caspase-1 inhibition improves renal function effectively.

Pulmonary artery perfusion with anti-tumor necrosis factor alpha antibody reduces cardiopulmonary bypass-induced inflammatory lung injury in a rabbit model

Inflammatory lung injury is one of the main complications associated with cardiopulmonary bypass (CPB). Tumor necrosis factor-α (TNF-α) is one of the key factors mediating the CPB-induced inflammatory reactions. Our previous studies have shown that endotracheal administration of anti-tumor necrosis factor-α antibody (TNF-α Ab) produces some beneficial effects on lung in a rabbit CPB model. In this study, we further examined the effects of pulmonary artery perfusion with TNF-α Ab (27 ng/kg) on lung tissue integrity and pulmonary inflammation during CPB and investigated the mechanism underlying the TNF-α Ab-mediated effects in a rabbit model of CPB. Our results from transmission electron microscopy showed that the perfusion with TNF-α Ab alleviated CPB-induced histopathological changes in lung tissue. The perfusion with TNF-α Ab also prevented CPB-induced pulmonary edema and improved oxygenation index. Parameters indicating pulmonary inflammation, including neutrophil count and plasma TNF-α and malondialdehyde (MDA) levels, were significantly reduced during CPB by pulmonary artery perfusion with TNF-α Ab, suggesting that the perfusion with TNF-α Ab reduces CPB-induced pulmonary inflammation. We further investigated the molecular mechanism underlying the protective effects of TNF-α Ab on lung. Our quantitative RT-PCR analysis revealed that pulmonary artery perfusion with TNF-α Ab significantly decreased TNF-α expression in lung tissue during CPB. The apoptotic index in lung tissue and the expression of proteins that play stimulatory roles in apoptosis pathways including the fas ligand (FasL) and Bax were markedly reduced during CPB by the perfusion with TNF-α Ab. In contrast, the expression of Bcl-2, which plays an inhibitory role in apoptosis pathways, was significantly increased during CPB by the perfusion with TNF-α Ab, indicating that the perfusion with TNF-α Ab significantly reduces CPB-induced apoptosis in lung. Thus, our study suggests that pulmonary artery perfusion with TNF-α Ab might be a promising approach for attenuating CPB-induced inflammatory lung injury.

Inflammation in intracerebral hemorrhage: from mechanisms to clinical translation

Intracerebral hemorrhage (ICH) accounts for 10-15% of all strokes and is associated with high mortality and morbidity. Currently, no effective medical treatment is available to improve functional outcomes in patients with ICH. Potential therapies targeting secondary brain injury are arousing a great deal of interest in translational studies. Increasing evidence has shown that inflammation is the key contributor of ICH-induced secondary brain injury. Inflammation progresses in response to various stimuli produced after ICH. Hematoma components initiate inflammatory signaling via activation of microglia, subsequently releasing proinflammatory cytokines and chemokines to attract peripheral inflammatory infiltration. Hemoglobin (Hb), heme, and iron released after red blood cell lysis aggravate ICH-induced inflammatory injury. Danger associated molecular patterns such as high mobility group box 1 protein, released from damaged or dead cells, trigger inflammation in the late stage of ICH. Preclinical studies have identified inflammatory signaling pathways that are involved in microglial activation, leukocyte infiltration, toll-like receptor (TLR) activation, and danger associated molecular pattern regulation in ICH. Recent advances in understanding the pathogenesis of ICH-induced inflammatory injury have facilitated the identification of several novel therapeutic targets for the treatment of ICH. This review summarizes recent progress concerning the mechanisms underlying ICH-induced inflammation. We focus on the inflammatory signaling pathways involved in microglial activation and TLR signaling, and explore potential therapeutic interventions by targeting the removal of hematoma components and inhibition of TLR signaling.