Early release of macrophage migration inhibitory factor after liver ischemia and reperfusion injury in rats

Metabolomics Applied to Cord Serum in Preeclampsia Newborns: Implications for Neonatal Outcomes

Preeclampsia (PE) is one of the leading causes of maternal and perinatal morbidity and mortality. However, it is still uncertain how PE affects neonate metabolism. We conducted an untargeted metabolomics analysis of cord blood to explore the metabolic changes in PE neonates. Umbilical cord serum samples from neonates with preeclampsia (n = 29) and non-preeclampsia (non-PE) (n = 32) pregnancies were analyzed using the UHPLC-QE-MS metabolomic platform. Different metabolites were screened, and pathway analysis was conducted. A subgroup analysis was performed among PE neonates to compare the metabolome between appropriate-for-gestational-age infants (n = 21) and small-for-gestational-age (SGA) infants (n = 8). A total of 159 different metabolites were detected in PE and non-PE neonates. Creatinine, N4-acetylcytidine, sphingomyelin (D18:1/16:0), pseudouridine, uric acid, and indolelactic acid were the most significant differential metabolites in the cord serum of PE neonates. Differential metabolite levels were elevated in PE neonates and were involved in the following metabolic pathways: glycine, serine, and threonine metabolism; sphingolipid, glyoxylate, and dicarboxylate metabolism; and arginine biosynthesis. In PE neonates, SGA neonates showed increased levels of hexacosanoyl carnitine and decreased abundance of 3-hydroxybutyric acid and 3-sulfinoalanine. Taurine-related metabolism and ketone body-related pathways were mainly affected. Based on the UHPLC-QE-MS metabolomics analysis, we identified the metabolic profiles of PE and SGA neonates. The abundance of metabolites related to certain amino acid, sphingolipid, and energy metabolism increased in the umbilical cord serum of PE neonates.

Glycinergic Signaling in Macrophages and Its Application in Macrophage-Associated Diseases

Accumulating evidences support that amino acids direct the fate decision of immune cells. Glycine is a simple structural amino acid acting as an inhibitory neurotransmitter. Besides, glycine receptors as well as glycine transporters are found in macrophages, indicating that glycine alters the functions of macrophages besides as an inhibitory neurotransmitter. Mechanistically, glycine shapes macrophage polarization via cellular signaling pathways (e.g., NF-κB, NRF2, and Akt) and microRNAs. Moreover, glycine has beneficial effects in preventing and/or treating macrophage-associated diseases such as colitis, NAFLD and ischemia-reperfusion injury. Collectively, this review highlights the conceivable role of glycinergic signaling for macrophage polarization and indicates the potential application of glycine supplementation as an adjuvant therapy in macrophage-associated diseases.

The Role of MIF in Hepatic Function, Oxidative Stress, and Inflammation in Thioacetamide-induced Liver Injury in Mice: Protective Effects of Betaine

BACKGROUND

Macrophage migration inhibitory factor (MIF) is a multipotent cytokine that contributes to the inflammatory response to chemical liver injury. This cytokine exhibits pro- and anti-inflammatory effects depending on the etiology and stage of liver disease.

OBJECTIVE

Our study aimed to investigate the role of MIF in oxidative stress and inflammation in the liver, and modulatory effects of betaine on MIF in thioacetamide (TAA)-induced chronic hepatic damage in mice.

METHODS

The experiment was performed on wild type and knockout MIF-/- C57BL/6 mice. They were divided into the following groups: control; Bet-group that received betaine (2% wt/v dissolved in drinking water); MIF-/- mice group; MIF-/-+Bet; TAA-group that received TAA (200 mg/kg b.w.), intraperitoneally, 3x/week/8 weeks); TAA+Bet; MIF-/-+TAA, and MIF-/-+TAA+Bet. In TAA- and Bet-treated groups, animals received the same doses. After eight weeks of treatment, blood samples were collected for biochemical analysis, and liver specimens were prepared for the assessment of parameters of oxidative stress and inflammation.

RESULTS

In MIF-/-mice, TAA reduced transaminases, γ-glutamyltranspeptidase, bilirubin, malondialdehyde (MDA), oxidative protein products (AOPP), total oxidant status (TOS), C-reactive protein (CRP), IL-6, IFN-γ, and increased thiols and total antioxidant status (TAS). Betaine attenuated the mechanism of MIF and mediated effects in TAA-induced liver injury, reducing transaminases, γ-glutamyltranspeptidase, bilirubin, MDA, AOPP, TOS, CRP, IL-6, IFN-g, and increasing thiols.

CONCLUSION

MIF is a mediator in hepatotoxic, pro-oxidative, and proinflammatoryeffects of TAA-induced liver injury. MIF-targeted therapy can potentially mitigate oxidative stress and inflammation in the liver, but the exact mechanism of its action requires further investigation. Betaine increases anti-oxidative defense and attenuates hepatotoxic effects of MIF, suggesting that betaine can be used for the prevention and treatment of liver damage.

Signaling pathways involved in p38-ERK and inflammatory factors mediated the anti-fibrosis effect of AD-2 on thioacetamide-induced liver injury in mice

Ginseng is a type of medicinal and edible homologous plant that is very common in medicine, food and even cosmetics.

Protective effect of electro-acupuncture on liver ischemia-reperfusion injury in rats

Liver ischemia-reperfusion injury is an important clinical complication in which excessive inflammation is a key factor; however, few studies have provided effective means of its regulation. As previous studies suggested that electro-acupuncture (EA) is able control excessive inflammation, the present study aimed to explore its effects on liver ischemia-reperfusion injury in experimental rats. The animals were randomly divided into surgery and sham groups, which were further divided into four sub-groups, including a non-treatment (NT), a non-point acupuncture (NPA), the non-selective nicotinic acetylcholine receptor (AChR) agonist 1,1-dimethyl-4-phenyl L-pioperazinium iodide (DMPPI) and an EA group. The alanine aminotransferase (ALT), serum cytokine and myeloperoxidase (MP) levels and the tissue pathology were evaluated after 90 min of ischemia followed by a 4, 8 or 24 h reperfusion. The results demonstrated that EA and DMPPI suppressed serum ALT elevation at 4 and 8 h reperfusion, whereas NPA did not. I/R induced hepatocellular necrosis, and cytoplasmic vacuolization and sinusoidal congestion was ameliorated by EA treatment after an 8 and 24 h reperfusion. In addition, EA also inhibited liver neutrophil accumulation, evidenced by a decreased MPO level at 8 h reperfusion. EA also suppressed the release of serum inflammatory factors TNF-α and IL-6 for the duration of reperfusion. However, little influence on IL-10 was observed. Mechanistically, vagus block by subphrenic vagotomy or mecamylamine hydrochloride abolished EA effect on liver damage, neutrophil accumulation and inflammatory factor release. In conclusion, it was demonstrated that EA protects the liver against I/R induced injury by inhibiting the inflammatory response, which is associated with the vagus.

TLR7 and TLR8 agonist resiquimod (R848) differently regulates MIF expression in cells and organs

Since its first description in 1966, macrophage migration inhibitory factor (MIF) was found to play a critical role in inflammatory and immune responses as well as in disease pathogenesis especially in tumor pathogenesis and cancer progression. MIF is expressed in different cell types and is associated with many disease severity and tumor pathogenesis. Here, we investigated the influence of TLR7 and TLR8 agonist resiquimod (R848), an immune response inducer used as a prophylactic agent for several infectious diseases as well as anticancer agents and vaccine adjuvant on MIF expression in cells and organs. Humans, mice and rats cell lines from different tissues (blood, retinal, nasopharynx, brain and liver) and C57BL/6J mice organs (brain, liver and spleen) were used for this investigation. In vitro, R848 induced MIF gene overexpression except in brain and liver cells. Furthermore, it enhanced cells ability to release soluble MIF and differently regulated mRNA expression of MIF-related receptors (CD74, CXCR4, CXCR2 and CD44). Its influence on MIF gene expression and MIF proteins release was more consistent in cancer cells. In vivo, a strong positive expression of MIF was observed in different regions in brain and spleen in response to R848 treatment; however in liver, increased MIF expression was observed in hepatocytes only. On the other hand, R848 treatment had induced a slight enhancement of MIF concentration in the plasma of C57BL/6J mice. Taken together, these data suggest that R848 differently regulates MIF mRNA expression depending on organ types and could influence MIF concentration in cellular microenvironment.

Graft-derived macrophage migration inhibitory factor correlates with hepatocellular injury in patients undergoing liver transplantation

Experimental studies suggest that macrophage migration inhibitory factor (MIF) mediates ischemia/reperfusion injury during liver transplantation. This study assessed whether human liver grafts release MIF during preservation, and whether the release of MIF is proportional to the extent of hepatocellular injury. Additionally, the association between MIF and early allograft dysfunction (EAD) after liver transplantation was evaluated. Concentrations of MIF, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and creatine kinase (CK) were measured in effluents of 38 liver grafts, and in serum of recipients. Concentrations of MIF in the effluent were greater than those in the recipients' serum before and after reperfusion (58 [interquartile range, IQR:23-79] μg/mL vs 0.06 [IQR:0.03-0.07] μg/mL and 1.3 [IQR:0.7-1.8] μg/mL, respectively; both P<.001). Effluent MIF concentrations correlated with effluent concentrations of the cell injury markers ALT (R=.51, P<.01), AST (R=.51, P<.01), CK (R=.45, P=.01), and LDH (R=.56, P<.01). Patients who developed EAD had greater MIF concentrations in effluent and serum 10 minutes after reperfusion than patients without EAD (Effluent: 80 [IQR:63-118] μg/mL vs 36 [IQR:20-70] μg/mL, P=.02; Serum: 1.7 [IQR:1.2-2.5] μg/mL vs 1.1 [IQR:0.6-1.7] μg/mL, P<.001).

CONCLUSION

Human liver grafts release MIF in proportion to hepatocellular injury. Greater MIF concentrations in effluent and recipient's serum are associated with EAD after liver transplantation.

Poly(ε-benzyloxycarbonyl-L-lysine)-grafted branched polyethylenimine as efficient nanocarriers for indomethacin with enhanced oral bioavailability and anti-inflammatory efficacy

Star-block copolymers PEI-g-PZLL with a branched polyethylenimine (PEI) core and multiple grafted poly(ε-benzyloxycarbonyl-L-lysine) (PZLL) peripheral chains were designed, synthesized, and evaluated as nanocarriers for indomethacin (IND). In an aqueous solution, PEI-g-PZLL self-assembled into spherical nanoparticles capable of encapsulating IND at high loading capacity and loading efficiency. Differential scanning calorimetry and X-ray diffraction measurements indicated that IND was molecularly or amorphously dispersed in the nanoparticles. Fourier transform infrared spectra revealed the presence of multiple intermolecular interactions, including hydrogen bonding, electrostatic forces, π-π stacking and hydrophobic interactions, between the block copolymer and the IND molecules. IND-loaded nanoparticles exhibited fast release under intestinal pH. Compared with raw IND, the utilization of PEI-g-PZLL as a carrier significantly enhanced the oral bioavailability of IND and improved its protective effect on renal ischemia-reperfusion injury, as evidenced by in vivo pharmacokinetic and pharmacodynamic studies. Cytotoxicity assay, histological observation and cellular uptake study suggested that PEI-g-PZLL was fairly biocompatible. All these results indicated that star-block copolymers PEI-g-PZLL could be used as efficient nanocarriers for IND and other poorly water-soluble drugs.

STATEMENT OF SIGNIFICANCE

The use of polyethylenimine (PEI) as an oral drug delivery carrier is limited because it is not biodegradable and the use of higher molecular weight PEI leads to improved efficiency but also increased cytotoxicity. The design of functionalized PEIs with low cytotoxicity and high efficiency is crucial for developing a successful oral drug delivery system. In our study, poly(ε-benzyloxycarbonyl-L-lysine) (PZLL)-grafted branched PEI (PEI-g-PZLL) was reported as an oral nanocarrier for indomethacin (IND). The low cytotoxicity and biodegradability, well-defined self-assembled nano-sized polymeric micelles, high loading capacity and loading efficiency, amorphous state of the encapsulated IND, as well as the enhanced oral bioavailability of IND, makes the copolymer PEI-g-PZLL a promising nanocarrier for the oral administration of IND and possibly other poorly water-soluble drugs.

Macrophage Migration Inhibitor Factor Upregulates MCP-1 Expression in an Autocrine Manner in Hepatocytes during Acute Mouse Liver Injury

Macrophage migration inhibitor factor (MIF), a multipotent innate immune mediator, is an upstream component of the inflammatory cascade in diseases such as liver disease. Monocyte chemoattractant protein-1 (MCP-1), a highly representative chemokine, is critical in liver disease pathogenesis. We investigated the role of MIF in regulating hepatocytic MCP-1 expression. MIF and MCP-1 expression were characterized by immunochemistry, RT-PCR, ELISA, and immunoblotting in CCl₄-treated mouse liver and isolated hepatocytes. MIF was primarily distributed in hepatocytes, and its expression increased upon acute liver injury. Its expression was also increased in injured hepatocytes, induced by LPS or CCl₄, which mimic liver injury in vitro. MIF was expressed earlier than MCP-1, strongly inducing hepatocytic MCP-1 expression. Moreover, the increase in MCP-1 expression induced by MIF was inhibited by CD74- or CD44-specific siRNAs and SB203580, a p38 MAPK inhibitor. Further, CD74 or CD44 deficiency effectively inhibited MIF-induced p38 activation. MIF inhibitor ISO-1 reduced MCP-1 expression and p38 phosphorylation in CCl₄-treated mouse liver. Our results showed that MIF regulates MCP-1 expression in hepatocytes of injured liver via CD74, CD44, and p38 MAPK in an autocrine manner, providing compelling information on the role of MIF in liver injury, and implying a new regulatory mechanism for liver inflammation.

Luteolin Exerts Cardioprotective Effects through Improving Sarcoplasmic Reticulum Ca(2+)-ATPase Activity in Rats during Ischemia/Reperfusion In Vivo

The flavonoid luteolin exists in many types of fruits, vegetables, and medicinal herbs. Our previous studies have demonstrated that luteolin reduced ischemia/reperfusion (I/R) injury in vitro, which was related with sarcoplasmic reticulum Ca²⁺-ATPase (SERCA2a) activity. However, the effects of luteolin on SERCA2a activity during I/R in vivo remain unclear. To investigate whether luteolin exerts cardioprotective effects and to monitor changes in SERCA2a expression and activity levels in vivo during I/R, we created a myocardial I/R rat model by ligating the coronary artery. We demonstrated that luteolin could reduce the myocardial infarct size, lactate dehydrogenase release, and apoptosis during I/R injury in vivo. Furthermore, we found that luteolin inhibited the I/R-induced decrease in SERCA2a activity in vivo. However, neither I/R nor luteolin altered SERCA2a expression levels in myocardiocytes. Moreover, the PI3K/Akt signaling pathway played a vital role in this mechanism. In conclusion, the present study has confirmed for the first time that luteolin yields cardioprotective effects against I/R injury by inhibiting the I/R-induced decrease in SERCA2a activity partially via the PI3K/Akt signaling pathway in vivo, independent of SERCA2a protein level regulation. SERCA2a activity presents a novel biomarker to assess the progress of I/R injury in experimental research and clinical applications.

MicroRNA 26a inhibits HMGB1 expression and attenuates cardiac ischemia-reperfusion injury

Ischemia reperfusion (IR) injury is a major issue in cardiac transplantation and inflammatory processes play a major role in myocardial IR injury. MicroRNA 26a (Mir-26a) plays important roles in cellular differentiation, cell growth, cell apoptosis and metastasis. Mir-26a has been demonstrated to modulate regulatory T cells expansion and attenuates renal IR injury. However, the role of Mir-26a in the cardiac IR injury has never been investigated. In our study, hearts of C57BL/6 mice were flushed and stored in cold Bretschneider solution for 8 hours and then transplanted into syngeneic recipients. The results demonstrate a crucial role for Mir-26a in inhibiting high mobility group box-1 (HMGB1) expression and attenuating cardiac IR injury. Mir-26a overexpression results in attenuated cardiac IR injury and inhibited HMGB1 expression. Mir-26a also inhibits inflammatory cells infiltration and cytokines expression. Furthermore, the attenuated cardiac IR injury induced by Mir-26a was abrogated by additional administration of recombinant HMGB1 (rHMGB1). In conclusion, Mir-26a plays a protective role in cardiomyocyte IR injury and this is associated with inhibited HMGB1 expression.

Comparative transcriptome profiling approach to glean virulence and immunomodulation-related genes of Fasciola hepatica

BACKGROUND

Fasciola hepatica causes chronic liver disease, fasciolosis, leading to significant losses in the livestock economy and concerns for human health in many countries. The identification of F. hepatica genes involved in the parasite's virulence through modulation of host immune system is utmost important to comprehend evasion mechanisms of the parasite and develop more effective strategies against fasciolosis. In this study, to identify the parasite's putative virulence genes which are associated with host immunomodulation, we explored whole transcriptome of an adult F. hepatica using current transcriptome profiling approaches integrated with detailed in silico analyses. In brief, the comparison of the parasite transcripts with the specialised public databases containing sequence data of non-parasitic organisms (Dugesiidae species and Caenorhabditis elegans) or of numerous pathogens and investigation of the sequences in terms of nucleotide evolution (directional selection) and cytokine signaling relation were conducted.

RESULTS

NGS of the whole transcriptome resulted in 19,534,766 sequence reads, yielding a total of 40,260 transcripts (N₅₀ = 522 bp). A number of the parasite transcripts (n = 1,671) were predicted to be virulence-related on the basis of the exclusive homology with the pathogen-associated data, positive selection or relationship with cytokine signaling. Of these, a group of the virulence-related genes (n = 62), not previously described, were found likely to be associated with immunomodulation based on in silico functional categorisation, showing significant sequence similarities with various immune receptors (i.e. MHC I class, TGF-β receptor, toll/interleukin-1 receptor, T-cell receptor, TNF receptor, and IL-18 receptor accessory protein), cytokines (i.e. TGF-β, interleukin-4/interleukin-13 and TNF-α), cluster of differentiations (e.g. CD48 and CD147) or molecules associated with other immunomodulatory mechanisms (such as regulation of macrophage activation). Some of the genes (n = 5) appeared to be under positive selection (Ka/Ks > 1), imitating proteins associated with cytokine signaling (through sequence homologies with thrombospondin type 1, toll/interleukin-1 receptor, TGF-β receptor and CD147).

CONCLUSIONS

With a comparative transcriptome profiling approach, we have identified a number of potential immunomodulator genes of F. hepatica (n = 62), which are firstly described here, could be employed for the development of better strategies (including RNAi) in the battle against both zoonotically and economically important disease, fasciolosis.

Macrophage migration inhibitory factor as a potential predictor for requirement of renal replacement therapy after orthotopic liver transplantation

Acute kidney injury (AKI) after orthotopic liver transplantation (OLT) is associated with a poor clinical outcome. Because there is no specific treatment for postoperative AKI, early recognition and prevention are fundamental therapeutic approaches. Concentrations of the proinflammatory cytokine macrophage migration inhibitory factor (MIF) are elevated in patients with kidney disease. We hypothesized that plasma MIF concentrations would be greater in patients developing AKI after OLT compared with patients with normal kidney function. Twenty-eight patients undergoing OLT were included in the study. Kidney injury was classified according to AKI network criteria. Fifteen patients (54%) developed severe AKI after OLT, 11 (39%) requiring renal replacement therapy (RRT). On the first postoperative day, patients with severe AKI had greater plasma MIF concentrations (237 ± 123 ng/mL) than patients without AKI (95 ± 63 ng/mL; P < 0.001). The area under the receiver operating characteristic (ROC) curve for predicting severe AKI was 0.87 [95% confidence interval (CI), 0.69-0.97] for plasma MIF, 0.61 (95% CI, 0.40-0.79) for serum creatinine (sCr), and 0.90 (95% CI, 0.72-0.98) for delta serum creatinine (ΔsCr). Plasma MIF (P = 0.02) and ΔsCr (P = 0.01) yielded a better predictive value than sCr for the development of severe AKI. Furthermore, the area under the ROC curve to predict the requirement of RRT was 0.87 (95% CI, 0.68-0.96) for plasma MIF, 0.65 (95% CI, 0.44-0.82) for sCr, and 0.72 (95% CI, 0.52-0.88) for ΔsCr. Plasma MIF had a better predictive value than sCr for the requirement of RRT (P = 0.02). In conclusion, postoperative plasma MIF concentrations were elevated in patients who developed severe AKI after OLT. Furthermore, plasma MIF concentrations showed a good prognostic value for identifying patients developing severe AKI or requiring postoperative RRT after OLT.

Lipocalin-2 promotes m1 macrophages polarization in a mouse cardiac ischaemia-reperfusion injury model

Ischaemia-reperfusion (IR) injury is a major issue in cardiac transplantation. Inflammatory processes play a major role in myocardial IR injury. Lipocalin-2 (Lcn2), which is also known as neutrophil gelatinase-associated lipocalin, has multiple functions that include the regulation of cell death/survival, cell migration/invasion, cell differentiation and iron delivery. In our study, the hearts of C57BL/6 mice were flushed with and stored in cold Bretschneider solution for 8 h and then transplanted into a syngeneic recipient. We found that Lcn2 neutralization decreased the recruitment of neutrophils and macrophages. Troponin T (TnT) production, 24 h after myocardial IR injury, was reduced through anti-Lcn2 antibody administration. The cardiac output at 60 mmHg of afterload pressure was significantly increased in hearts administrated with anti-Lcn2 antibody administration (anti-Lcn-2: 58.9 ± 5.62 ml/min; control: 25.8 ± 4.1 ml/min; P < 0.05). Anti-Lcn2 antibody treatment suppressed M1 marker (IL-12, IL-23 and iNOS) expression but increased M2 marker (IL-10, Arg1 and Mrc1) expression. Furthermore, in our vitro and vivo experiments, we found that anti-Lcn2 antibody treatment failed to induce M1-related gene expression in response to LPS and that Lcn2 neutralization enhanced the expression of M2-related genes following IL-4 treatment. In conclusion, Lcn2 promotes M1 polarization, and Lcn2 neutralization attenuates cardiac IR injury.

Netrin-1 attenuates cardiac ischemia reperfusion injury and generates alternatively activated macrophages

Ischemia reperfusion (IR) injury is a major issue in cardiac transplantation and inflammatory processes play a major role in myocardial IR injury. Netrin-1 is a laminin-related protein identified as a neuronal guidance cue and netrin-1 expressed outside the nervous system inhibits migration of leukocytes in vitro and in vivo and attenuates inflammation-mediated tissue injury. In our study, hearts of C57BL/6 mice were flushed and stored in cold Bretschneider solution for 8 h and then transplanted into syngeneic recipient. We found that netrin-1 decreased cardiomyocyte apoptosis and recruitment of neutrophils and macrophages. Troponin T (TnT) production on 24 h after myocardial IR injury was reduced by netrin-1 administration. Cardiac output at 60 mmHg of afterload pressure was significantly increased in hearts with netrin-1 administration (IR + Netrin-1: 59.9 ± 5.78 ml/min; IR: 26.2 ± 4.3 ml/min; P < 0.05). Netrin-1 treatment increased expression of the alternatively activated macrophage (AAM) markers arginase-1 (Arg-1) and mannose receptor (MR) and promoted proliferator-activated receptor γ (PPARγ) expression in cardiac allograft. Furthermore, decreased TnT expression and reduced allograft infiltration of neutrophils and monocytes/macrophages by netrin-1 was abolished with addition of PPARγ antagonist. In conclusion, netrin-1 attenuates cardiac IR injury and generates AAM which contributes to the protective effect of netrin-1.

Nuclear factor-κB activation inhibitor attenuates ischemia reperfusion injury and inhibits Hmgb1 expression

OBJECTIVE AND DESIGN

To investigate the effects of nuclear factor-κB activation inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) on cardiac ischemia reperfusion injury in a transplantation model.

METHODS

Hearts of C57BL/6 mice were flushed and stored in cold Bretschneider solution for 8 h and then transplanted into syngeneic recipient. Some mice were administrated intraperitoneally with DHMEQ (8 mg/kg) 1 h before reperfusion. For inhibition of Hmgb1, mice were treated with glycyrrhizin at 250 mg/kg prior to reperfusion.

RESULTS

DHMEQ decreased cardiomyocyte apoptosis and recruitment of neutrophils and macrophages. Troponin T (TnT) production on 24 h after myocardial IR injury was reduced by DHMEQ treatment. Cardiac output at 60 mmHg of afterload pressure was significantly increased in hearts with DHMEQ treatment (IR+DHMEQ: 58.6 ± 5.75 ml/min; IR: 25.9 ± 4.1 ml/min; P < 0.05). Furthermore, DHMEQ suppressed high mobility group protein (Hmgb1) expression. And the Caspase 3 activity, the number of TUNEL-positive cardiomyocytes and infiltrated neutrophil in cardiac allograft were markedly decreased with Hmgb1 inhibitor treatment.

CONCLUSIONS

Nuclear factor-κB activation inhibitor DHMEQ attenuates ischemia reperfusion injury in a cardiac transplantation model and it may be a suitable agent for the protection of the cardiac against ischemia reperfusion injury.

Necrostatin-1 inhibits Hmgb1-IL-23/IL-17 pathway and attenuates cardiac ischemia reperfusion injury

Ischemia reperfusion (IR) injury is a major issue in cardiac transplantation and inflammatory processes play a major role in myocardial IR injury. Necrostatin-1 (Nec-1) is a small molecule capable of inhibiting RIP1 kinase activity and attenuates inflammation-mediated tissue injury. In our study, hearts of C57Bl/6 mice were flushed and stored in cold Bretschneider solution for 8 h and then transplanted into syngeneic recipients. We found that Nec-1 decreased cardiomyocyte necrosis and recruitment of neutrophils and macrophages. Troponin T (TnT) production on 24 h after myocardial IR injury was reduced by Nec-1 administration. Cardiac output at 60 mmHg of afterload pressure was significantly increased in hearts with Nec-1 administration and the cardiac allograft survival in Nec-1-treated animals was significantly prolonged (MST = 90 days in IR + Nec-1 group, P < 0.05 as compared with IR group, MST = 83.5 days). Nec-1 treatment attenuated ROS generation and increased expression of NOS2 and COX-2. The expression of Hmgb1, IL-23, and IL-17A were also decreased with Nec-1 administration. Furthermore, the decreased TnT expression induced by Nec-1 was abrogated with exogenous Hmgb1 administration. In conclusion, Nec-1 played a protective role in cardiomyocyte IR injury, and this was associated with inhibited Hmgb1-IL-23/IL-17 pathway.

Innate immunity and cell death in alcoholic liver disease: role of cytochrome P4502E1

Ethanol-induced liver injury is a complex process dependent upon the interaction of multiple cell types in the liver, as well as activation of the innate immune response. Increased expression of CYP2E1 in response to high concentrations of ethanol leads to greater production of cytotoxic ethanol metabolites, which in turn contribute to production of reactive oxygen species, oxidative stress, and ultimately, cell death. Necroptotic hepatocyte cell death in response to ethanol is mediated via a CYP2E1-dependent expression of receptor-interacting protein kinase 3 (RIP3), a key component of the necroptosome. In response to alarmins released during ethanol-induced necroptosis, the innate immune response is activated. Macrophage migration inhibitory factor (MIF), a pro-inflammatory multikine involved in many disease processes, is an essential component to this response to injury. MIF expression is increased during ethanol exposure via a CYP2E1-dependent pathway, likely contributing to an exacerbated innate immune response and chronic inflammation after chronic ethanol. This review will discuss the complex interactions between CYP2E1-dependent expression of RIP3 and MIF in the pathophysiology of chronic ethanol-induced liver injury.

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Alcohol induces hepatocellular death via both apoptosis and necroptosis.

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Receptor interacting kinase 3 (RIP3) mediates necroptotic cell death.

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Alcohol-induced injury activates innate immune responses, including MIF.

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Interactions between innate immunity and cell death with ethanol are reviewed.

Macrophage migration inhibitory factor contributes to ethanol-induced liver injury by mediating cell injury, steatohepatitis, and steatosis

Macrophage migration inhibitory factor (MIF), a multipotent protein that exhibits both cytokine and chemotactic properties, is expressed by many cell types, including hepatocytes and nonparenchymal cells. We hypothesized that MIF is a key contributor to liver injury after ethanol exposure. Female C57BL/6 or MIF-/- mice were fed an ethanol-containing liquid diet or pair-fed control diet for 4 (11% total kcal;early response) or 25 (32% kcal; chronic response) days. Expression of MIF messenger RNA (mRNA) was induced at both 4 days and 25 days of ethanol feeding. After chronic ethanol, hepatic triglycerides and plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were increased in wildtype, but not MIF-/-, mice. In order to understand the role of MIF in chronic ethanol-induced liver injury, we investigated the early response of wildtype and MIF-/- to ethanol. Ethanol feeding for 4 days increased apoptosis of hepatic macrophages and activated complement in both wildtype and MIF-/- mice. However, tumor necrosis factor alpha (TNF-α) expression was increased only in wildtype mice. This attenuation of TNF-α expression was associated with fewer F4/80+ macrophages in liver of MIF-/- mice. After 25 days of ethanol feeding, chemokine expression was increased in wildtype mice, but not MIF-/- mice. Again, this protection was associated with decreased F4/80+ cells in MIF-/- mice after ethanol feeding. Chronic ethanol feeding also sensitized wildtype, but not MIF-/-, mice to lipopolysaccharide, increasing chemokine expression and monocyte recruitment into the liver.

CONCLUSION

Taken together, these data indicate that MIF is an important mediator in the regulation of chemokine production and immune cell infiltration in the liver during ethanol feeding and promotes ethanol-induced steatosis and hepatocyte damage.

The expressions of MIF and CXCR4 protein in tumor microenvironment are adverse prognostic factors in patients with esophageal squamous cell carcinoma

Background

Tumor-derived cytokines and their receptors usually take important roles in the disease progression and prognosis of cancer patients. In this survey, we aimed to detect the expression levels of MIF and CXCR4 in different cell populations of tumor microenvironments and their association with survivals of patients with esophageal squamous cell carcinoma (ESCC).

Methods

MIF and CXCR4 levels were measured by immunochemistry in tumor specimens from 136 resected ESCC. Correlation analyses and independent prognostic outcomes were determined using Pearson’s chi-square test and Cox regression analysis.

Results

The expression of CXCR4 in tumor cells was positively associated with tumor status (P = 0.045) and clinical stage (P = 0.044); whereas the expression of CXCR4 in tumor-infiltrating lymphocytes (TILs) and the expression of MIF in tumor cells and in TILs were not associated with clinical parameters of ESCC patients. High MIF expression in tumor cells or in TILs or high CXCR4 expression in tumor cells was significantly related to poor survival of ESCC patients (P < 0.05). Multivariate analysis showed that the expression of MIF or CXCR4 in tumor cells and the expression of MIF in TILs were adverse independent factors for disease-free survival (DFS) and overall survival (OS) in the whole cohort of patients (P < 0.05). Furthermore, the expression of MIF and CXCR4 in tumor cells were independent factors for reduced DFS and OS in metastatic/recurrent ESCC patients (P < 0.05). Interestingly, the expressions of MIF and CXCR4 in tumor cells and in TILs were significantly positively correlated (P < 0.05), and the combined MIF and CXCR4 expression in tumor cells was an independent adverse predictive factor for DFS and OS (P < 0.05).

Conclusion

The expressions of MIF and CXCR4 proteins in tumor cells and TILs have different clinically predictive values in ESCC.

Effects of N-n-butyl haloperidol iodide on the rat myocardial sarcoplasmic reticulum Ca(2+)-ATPase during ischemia/reperfusion

We have previously shown that N-n-butyl haloperidol iodide (F(2)), a newly synthesized compound, reduces ischemia/reperfusion (I/R) injury by preventing intracellular Ca(2+) overload through inhibiting L-type calcium channels and outward current of Na(+)/Ca(2+) exchanger. This study was to investigate the effects of F(2) on activity and protein expression of the rat myocardial sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) during I/R to discover other molecular mechanisms by which F(2) maintains intracellular Ca(2+) homeostasis. In an in vivo rat model of myocardial I/R achieved by occluding coronary artery for 30-60 min followed by 0-120 min reperfusion, treatment with F(2) (0.25, 0.5, 1, 2 and 4 mg/kg, respectively) dose-dependently inhibited the I/R-induced decrease in SERCA activity. However, neither different durations of I/R nor different doses of F(2) altered the expression levels of myocardial SERCA2a protein. These results indicate that F(2) exerts cardioprotective effects against I/R injury by inhibiting I/R-mediated decrease in SERCA activity by a mechanism independent of SERCA2a protein levels modulation.

Oxidation of HMGB1 causes attenuation of its pro-inflammatory activity and occurs during liver ischemia and reperfusion

High mobility group box 1 (HMGB1) is a nuclear transcription factor. Once HMGB1 is released by damaged cells or activated immune cells, it acts as danger molecule and triggers the inflammatory signaling cascade. Currently, evidence is accumulating that posttranslational modifications such as oxidation may modulate the pro-inflammatory potential of danger signals. We hypothesized that oxidation of HMGB1 may reduce its pro-inflammatory potential and could take place during prolonged ischemia and upon reperfusion.

Liver grafts were cold preserved for 24 h and flushed with saline in hourly intervals to collect the effluent. Liver grafts, cold-preserved for 6 h, were transplanted into syngeneic recipients to obtain serum and liver samples 24 h after initiation of reperfusion. Addition of the effluent to a macrophage culture induced the synthesis of tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6. The stimulatory activity of graft effluent was reduced after depletion of HMGB1 via immunoprecipitation. Oxidation of the effluent HMGB1 using H₂O₂ attenuated its stimulatory activity as well. Liver transplantation of cold preserved grafts caused HMGB1 translocation and release as determined by immunohistochemistry and ELISA-assay, respectively. Using Western blot with non-reducing conditions revealed the presence of oxidized HMGB1 in liver samples obtained after 12 h and in effluent samples after 16 h of cold preservation as well as in liver and serum samples obtained 24 h after reperfusion.

These observations confirm that post-translational oxidation of HMGB1 attenuates its pro-inflammatory activity. Oxidation of HMGB1 as induced during prolonged ischemia and by reoxygenation during reperfusion in vivo might also attenuate its pro-inflammatory activity. Our findings also call for future studies to investigate the mechanism of the inhibitory effect of oxidized HMGB1 on the pro-inflammatory potential.