The liver protection of propylene glycol alginate sodium sulfate preconditioning against ischemia reperfusion injury: focusing MAPK pathway activity

O-sialoglycoprotein Endopeptidase (OSGEP) Suppresses Hepatic Ischemia-Reperfusion Injury-Induced Ferroptosis Through Modulating the MEK/ERK Signaling Pathway

Hepatic ischemia-reperfusion injury (HIRI) was widely accepted as a critical complication of liver resection and transplantation. A growing body of evidence suggested that O-sialoglycoprotein endopeptidase (OSGEP) was involved in cell proliferation and mitochondrial metabolism. However, whether OSGEP could mediate the pathogenesis of HIRI has still remained unclarified. This study investigated whether OSGEP could be protective against HIRI and elucidated the potential mechanisms. The OSGEP expression level was detected in cases undergoing ischemia-related hepatectomy and a stable oxygen-glucose deprivation/reoxygenation (OGD/R) condition in hepG2 cells. Additionally, it was attempted to establish a mouse model of HIRI, thus, the function and mechanism of OSGEP could be analyzed. At one day after hepatectomy, the negative association of OSGEP expression level with the elevated serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was noted. Moreover, it was attempted to carry out gain- and loss-of-function analyses of OSGEP in hepG2 cells to reveal its influences on OGD/R-induced injury and relevant signaling pathways. The findings suggested that OSGEP overexpression significantly protected hepG2 cells against ferroptotic cell death, while OSGEP consumption had opposite effects. Consistent with in vitro studies, OSGEP deficiency exacerbated liver functions and ferroptotic cell death in a mouse model of HIRI. The results also revealed that OSGEP mediated the progression of HIRI by regulating the MEK/ERK signaling pathway. Rescue experiments indicated that ERK1/2 knockdown or overexpression reversed the effects of OSGEP overexpression or knockdown on hepG2 cells under OGD/R condition. Taken together, the findings demonstrated that OSGEP could contribute to alleviate HIRI by mediating the MEK-ERK signaling pathway, which may serve as a potential prognostic marker and a therapeutic target for HIRI.

Sulfated Alginate for Biomedical Applications

Alginate (Alg) polymers have received much attention due to the mild conditions required for gel formation and their good bio-acceptability. However, due to limited interactions with cells, many drugs, and biomolecules, chemically modified alginates are of great interest. Sulfated alginate (S-Alg) is a promising heparin-mimetic that continues to be investigated both as a drug molecule and as a component of biomaterials. Herein, the S-Alg literature of the past five years (2017-2023) is reviewed. Several methods used to synthesize S-Alg are described, with a focus on new advances in characterization and stereoselectivity. Material fabrication is another focus and spans bulk materials, particles, scaffolds, coatings, and part of multicomponent biomaterials. The new application of S-Alg as an antitumor agent is highlighted together with studies evaluating safety and biodistribution. The high binding affinity of S-Alg for various drugs and heparin-binding proteins is exploited extensively in biomaterial design to tune the encapsulation and release of these agents and this aspect is covered in detail. Recommondations include publishing key material properties to allow reproducibility, careful selection of appropriate sulfation strategies, the use of cross-linking strategies other than ionic cross-linking for material fabrication, and more detailed toxicity and biodistribution studies to inform future work.

Proanthocyanidin Alleviates Liver Ischemia/Reperfusion Injury by Suppressing Autophagy and Apoptosis via the PPARα/PGC1α Signaling Pathway

Background and Aims

Hepatic ischemia-reperfusion injury (IRI) is a common pathophysiological phenomenon in clinical practice, which usually occurs in liver transplantation, liver resection, severe trauma, and hemorrhagic shock. Proanthocyanidin (PC), exerted from various plants with antioxidant, antitumor, and antiaging activity, were administrated in our study to investigate the underlying mechanism of its protective function on IRI.

Methods

Two doses of PC (50 mg/kg, 100 mg/kg) were given to BALB/c mice by intragastric administration for 7 days before partial (70%) warm IR surgery. Serum and liver tissues were collected 2, 8, and 24 h after reperfusion for relevant experiments.

Results

The results of transaminase and hematoxylin and eosin staining indicated that PC pretreatment significantly alleviated IRI in mice. Serum total superoxide dismutase increased and malondialdehyde decreased in PC pretreatment groups. Enzyme-linked immunosorbent assays, western blotting, quantitative real-time polymerase chain reaction, and immunohistochemistry showed that inflammation, apoptosis, and autophagy in PC preprocessing groups were significantly inhibited and were dose-dependent. The protein, mRNA expression, and immunohistochemical staining results of peroxisome proliferator-activated receptor alpha (PPARα) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) in the PC pretreatment groups were significantly upregulated compared with the IR group in a dose-dependent manner.

Conclusions

PC pretreatment suppressed inflammation, apoptosis, and autophagy via the PPAR-α signaling pathway to protect against IRI of the liver in mice.

Dexmedetomidine attenuates hepatic ischemia-reperfusion injury-induced apoptosis via reducing oxidative stress and endoplasmic reticulum stress

Dexmedetomidine (DEX) affords a hepatoprotective effect during ischemia-reperfusion (IR) injury (IRI); however, the underlying mechanism remains elusive. In this work, using a rat liver IR model and a BRL-3A cell hypoxia-reoxygenation (HR) model, we explored whether DEX protects the liver against IRI by decreasing oxidative stress (OS), endoplasmic reticulum stress (ERS), and apoptotic pathways. We found that DEX significantly increased SOD and GSH activity while decreasing ROS and MDA levels in BRL-3A cells, successfully preventing HR-induced OS damage. DEX administration reduced JNK, ERK, and P38 phosphorylation and blocked HR-induced MAPK signaling pathway activation. Additionally, DEX administration reduced the expression of GRP78, IRE1α, XBP1, TRAF2, and CHOP, which reduced HR-induced ERS. NAC prevented the MAPK pathway from being activated and inhibited the ERS pathway. Further research showed that DEX significantly reduced HR-induced apoptosis by suppressing the expression of Bax/Bcl-2 and cleaved caspase-3. Similarly, animal studies demonstrated DEX exerted a protective effect of the liver by alleviating histopathological injury and enhancing liver function, mechanically DEX reduced cell apoptosis in liver tissue by reducing oxidative stress and ERS. In conclusion, DEX mitigates OS and ERS during IR, thereby suppressing cell apoptosis, thus providing protection to the liver.

MAPK Signaling Pathways in Hepatic Ischemia/Reperfusion Injury

The mitogen-activated protein kinase signaling pathway can be activated by a variety of growth factors, cytokines, and hormones, and mediates numerous intracellular signals related to cellular activities, including cell proliferation, motility, and differentiation. It has been widely studied in the occurrence and development of inflammation and tumor. Hepatic ischemia-reperfusion injury (HIRI) is a common pathophysiological phenomenon that occurs in surgical procedures such as lobectomy and liver transplantation, which is characterized by severe inflammatory reaction after ischemia and reperfusion. In this review, we mainly discuss the role of p38, ERK1/2, JNK in MAPK family and TAK1 and ASK1 in MAPKKK family in HIRI, and try to find an effective treatment for HIRI.

JNK and p38 gene and protein expression during liver ischemia-reperfusion in a rat model treated with silibinin

OBJECTIVES

Signal transduction of mitogen-activated protein kinases (MAPKs) is activated during ischemia. In this study, c-Jun N-terminal Kinase (JNK) and p38 MAPK (p38) gene and protein expression were evaluated as two members of the MAPK family during liver ischemia-reperfusion in rats.

MATERIALS AND METHODS

Thirty-two male Wistar rats were divided into four groups of eight: Vehicle, ischemia-reperfusion (IR), ischemia-reperfusion+silibinin (IR+SILI), and SILI. The IR and IR+SILI groups differed from the other two groups in that they underwent one hour of ischemia followed by three hr of reperfusion. The Vehicle and IR groups received normal saline while the SILI and IR+SILI groups were treated with silibinin (50 mg/kg). At the end of the reperfusion time, blood and ischemic liver tissue were collected for further experiments.

RESULTS

The expression of JNK and p38 gene, the amount of serum hepatic injury indices, and malondialdehyde (MDA) in the IR group increased significantly compared with the vehicle group. The JNK and p38 gene expression decreased significantly in the IR + SILI group compared with the IR group. Glutathione peroxidase (GPx) and total antioxidant capacity (TAC) levels decreased in the IR group while increasing in the IR+SILI group. Histological examination showed that silibinin significantly reduced the severity of hepatocyte degradation. Western blot results were completely consistent with real-time PCR results.

CONCLUSION

The possible pathways of the protective effect of silibinin against hepatic ischemia damages is to reduce the expression of the p38 and JNK gene and protein.

An overview on small molecules acting as broad spectrum-agents for yellow fever infection

INTRODUCTION

Yellow Fever virus (YFV) is a mosquito-borne flavivirus, endemic in 47 countries in Africa and South America, which causes febrile symptoms that can evolve in 15% of the patients to serious haemorrhagic conditions, liver injury, and multiorgan failure. Although a highly effective vaccine (YF-17D vaccine) is available, to date, no antiviral drugs have been approved for the prevention and treatment of YFV infections.

AREAS COVERED

This review article focuses on the description of viral targets that have been considered within YFV and flavivirus drug discovery studies and on the most relevant candidates reported so far that elicit broad-spectrum inhibition against relevant strains and mutants of YFV.

EXPERT OPINION

Considering the growing interest on (re)emerging vector-borne viral infections, it is expected that flavivirus drug discovery will quickly deliver potential candidates for clinical evaluation. Due to similarity among flaviviral targets, several candidates identified against different flaviviruses have shown broad-spectrum activity, thus exhibiting anti-YFV activity, as well. In this regard, it would be desirable to routinely include the assessment of antiviral activity against different YFV strains. On the other hand, the development of host targeting agents are still at an initial stage and deserve further focused efforts.

Dual Lactate Clearance in the Viability Assessment of Livers Donated After Circulatory Death With Ex Situ Normothermic Machine Perfusion

Supplemental Digital Content is available in the text.

Perfusate lactate clearance (LC) is considered one of the useful indicators of liver viability assessment during normothermic machine perfusion (NMP); however, the applicable scope and potential mechanisms of LC remain poorly defined in the setting of liver donation after circulatory death.

Design, synthesis and biological evaluation of 1-Aryl-5-(4-arylpiperazine-1-carbonyl)-1H-tetrazols as novel microtubule destabilizers

A series of 1-aryl-5-(4-arylpiperazine-1-carbonyl)-1H-tetrazols as microtubule destabilizers were designed, synthesised and evaluated for anticancer activity. Based on bioisosterism, we introduced the tetrazole moiety containing the hydrogen-bond acceptors as B-ring of XRP44X analogues. The key intermediates ethyl 1-aryl-1H-tetrazole-5-carboxylates 10 can be simply and efficiently prepared via a microwave-assisted continuous operation process. Among the compounds synthesised, compound 6-31 showed noteworthy potency against SGC-7901, A549 and HeLa cell lines. In mechanism studies, compound 6-31 inhibited tubulin polymerisation and disorganised microtubule in SGC-7901 cells by binding to tubulin. Moreover, compound 6-31 arrested SGC-7901cells in G2/M phase. This study provided a new perspective for development of antitumor agents that target tubulin.

New Insights Into the Role of Autophagy in Liver Surgery in the Setting of Metabolic Syndrome and Related Diseases

Visceral obesity is an important component of metabolic syndrome, a cluster of diseases that also includes diabetes and insulin resistance. A combination of these metabolic disorders damages liver function, which manifests as non-alcoholic fatty liver disease (NAFLD). NAFLD is a common cause of abnormal liver function, and numerous studies have established the enormously deleterious role of hepatic steatosis in ischemia-reperfusion (I/R) injury that inevitably occurs in both liver resection and transplantation. Thus, steatotic livers exhibit a higher frequency of post-surgical complications after hepatectomy, and using liver grafts from donors with NAFLD is associated with an increased risk of post-surgical morbidity and mortality in the recipient. Diabetes, another MetS-related metabolic disorder, also worsens hepatic I/R injury, and similar to NAFLD, diabetes is associated with a poor prognosis after liver surgery. Due to the large increase in the prevalence of MetS, NAFLD, and diabetes, their association is frequent in the population and therefore, in patients requiring liver resection and in potential liver graft donors. This scenario requires advancement in therapies to improve postoperative results in patients suffering from metabolic diseases and undergoing liver surgery; and in this sense, the bases for designing therapeutic strategies are in-depth knowledge about the molecular signaling pathways underlying the effects of MetS-related diseases and I/R injury on liver tissue. A common denominator in all these diseases is autophagy. In fact, in the context of obesity, autophagy is profoundly diminished in hepatocytes and alters mitochondrial functions in the liver. In insulin resistance conditions, there is a suppression of autophagy in the liver, which is associated with the accumulation of lipids, being this is a risk factor for NAFLD. Also, oxidative stress occurring in hepatic I/R injury promotes autophagy. The present review aims to shed some light on the role of autophagy in livers undergoing surgery and also suffering from metabolic diseases, which may lead to the discovery of effective therapeutic targets that could be translated from laboratory to clinical practice, to improve postoperative results of liver surgeries when performed in the presence of one or more metabolic diseases.

Inhibition of CKLF1 ameliorates hepatic ischemia-reperfusion injury via MAPK pathway

BACKGROUND

Hepatic ischemia/reperfusion (I/R) injury is a major complication of liver resection or transplantation. However, the mechanism underlying hepatic I/R injury remains obscure. The aim of the present study was to investigate the role of Chemokine-like factor 1 (CKLF1) in hepatic I/R injury.

METHODS

Rats were subjected to 70% hepatic ischemia for 90 min, followed by 6, 12, 24, 48 and 96 h of reperfusion. The expression of CKLF1 was measured by real-time PCR and western blot. The effect of C19, an antagonism peptide of CKLF1, on hepatic I/R injury was investigated.

RESULTS

After subjected to 70% hepatic ischemia and reperfusion, the ALT and AST were increased. H&E results showed serious liver damage. The mRNA and protein levels of CKLF1 expression were upregulated during hepatic I/R. Immunohistochemistry staining results showed that neutrophil infiltration was increased in the ischemia lobe. MPO activity was significantly higher post reperfusion. TNF-α and IL-1β were upregulated during hepatic I/R. C19 administration significantly reduced the level of ALT and AST, decreased the necrosis area of liver tissue. Furthermore, C19 treatment inhibited neutrophil infiltration and reduced MPO activity. Meanwhile, C19 decreased the expression of TNF-α and IL-1β. The phosphorylation of P38, JNK were inhibited by C19 treatment.

CONCLUSION

CKLF1 was upregulated during hepatic I/R. Inhibiting CKLF1 by C19, an antagonism peptide of CKLF1, could alleviate hepatic I/R injury, reduce neutrophil infiltration, decrease inflammatory response. The protective effect of C19 may related to MAPK signaling pathway.

The role of neutrophil extracellular traps and TLR signaling in skeletal muscle ischemia reperfusion injury

Ischemia reperfusion (IR) injury results in devastating skeletal muscle fibrosis. Here, we recapitulate this injury with a mouse model of hindlimb IR injury which leads to skeletal muscle fibrosis. Injury resulted in extensive immune infiltration with robust neutrophil extracellular trap (NET) formation in the skeletal muscle, however, direct targeting of NETs via the peptidylarginine deiminase 4 (PAD4) mechanism was insufficient to reduce muscle fibrosis. Circulating levels of IL-10 and TNFα were significantly elevated post injury, indicating toll-like receptor (TLR) signaling may be involved in muscle injury. Administration of hydroxychloroquine (HCQ), a small molecule inhibitor of TLR7/8/9, following injury reduced NET formation, IL-10, and TNFα levels and ultimately mitigated muscle fibrosis and improved myofiber regeneration following IR injury. HCQ treatment decreased fibroadipogenic progenitor cell proliferation and partially inhibited ERK1/2 phosphorylation in the injured tissue, suggesting it may act through a combination of TLR7/8/9 and ERK signaling mechanisms. We demonstrate that treatment with FDA-approved HCQ leads to decreased muscle fibrosis and increased myofiber regeneration following IR injury, suggesting short-term HCQ treatment may be a viable treatment to prevent muscle fibrosis in ischemia reperfusion and traumatic extremity injury.

Magnesium isoglycyrrhizinate ameliorates concanavalin A-induced liver injury via the p38 and JNK MAPK pathway

CONTEXT

Acute liver failure is a serious disease caused by a variety of factors, and immunological injury is an important pathological process. Comprehensive liver treatment efficacy is poor, and the mortality rate is high. Magnesium isoglycyrrhizinate (MgIG) is a new glycyrrhizin drug extracted from the traditional Chinese medicine licorice. The mechanism by which MgIG regulates ConcanavalinA (ConA)-induced immunological liver injury in mice is not completely clear.

MATERIALS AND METHODS

Immunological liver injury was induced in mice by ConA injection, and the inflammatory macrophages model was induced by lipopolysaccharide (LPS). MgIG was administered 30 min prior to ConA and LPS treatment. The mice in the different groups were sacrificed 12 h after treatment, and macrophages were measured at 30 min, 1 h, and 2 h after induction. Macrophages, liver, and blood samples were then collected for analysis.

RESULTS

After drug administration, the MgIG group showed a marked decrease in serum transaminase levels, reduced apoptosis and hepatic inflammatory responses compared to the ConA group. Furthermore, there was a significant reduction in inflammatory cytokine levels in the serum and liver tissue. In vitro, the expression of inflammatory cytokines was distinctly reduced after MgIG administration. In addition, MgIG pretreatment reduced the expression of inflammatory cytokines and regulated the phosphorylation of p38 and JNK proteins in the MAPK pathway.

CONCLUSION

These findings demonstrated that MgIG protects against ConA-induced immunological liver injury by markedly alleviating liver inflammation, and this provides guidance for the clinical amelioration of liver inflammation induced by immunological factors.

Ubiquitin-Specific Peptidase 10 Protects Against Hepatic Ischaemic/Reperfusion Injury via TAK1 Signalling

Ubiquitin-specific peptidase 10 (USP10) protein is a deubiquitination enzyme involved in many important biological processes. However, the function of USP10 in hepatic ischaemic/reperfusion (I/R) injury remains unknown. The aim of this study was to explore the role of USP10 in hepatic I/R injury. USP10 Heterozygote mice and primary hepatocytes were used to construct hepatic I/R models. The effect of USP10 on hepatic I/R injury was examined via pathological and molecular analyses. Our results indicated that USP10 was significantly downregulated in the livers of mice after hepatic I/R injury and in hepatocytes subjected to hypoxia/reoxygenation stimulation. USP10 Heterozygote mice exhibited exacerbated hepatic I/R injury, as evidenced by enhanced liver inflammation via the NF-κB signalling pathway and increased hepatocyte apoptosis. Additionally, USP10 overexpression inhibited hepatocyte inflammation and apoptosis in hepatic I/R injury in vitro and in vivo. Mechanistically, our study demonstrated that USP10 knockdown exerted its detrimental effects on hepatic I/R injury by inducing activation of the transforming growth factor β-activated kinase 1 (TAK1)-JNK/p38 signalling pathways. TAK1 was required for USP10 function in hepatic I/R injury as TAK1 inhibition abolished USP10 function in vitro. In conclusion, our study demonstrated that USP10 plays a protective role in hepatic I/R injury by inhibiting the activation of the TAK1-JNK/p38 signalling pathways. Modulation of USP10/TAK1 might be a promising strategy to prevent this pathological process.

Cafestol preconditioning attenuates apoptosis and autophagy during hepatic ischemia-reperfusion injury by inhibiting ERK/PPARγ pathway

OBJECTIVE

The study was aimed to explore the hepatocellular protective functions of cafestol during hepatic ischemia-reperfusion injury and the possible mechanisms.

METHODS

Ninety male Balb/c mice were randomly divided into seven groups, including normal control group, L-cafestol(20mg/kg) group, H-cafestol(40mg/kg) group, sham group, IR group, L-cafestol(20mg/kg) + IR group, H-cafestol(40mg/kg) + IR group. Serum liver enzymes (ALT, AST), inflammation mediators, proteins associated with apoptosis and autophagy, indicators linked with ERK/PPARγ pathway, and liver histopathology were measured using ELISA, qRT-PCR, immunohistochemical staining, and western blotting at 2, 8, and 24 hours after reperfusion.

RESULTS

Our findings confirmed that cafestol preconditioning groups could reduce the levels of ALT and AST, alleviate liver pathological damage, suppress the release of inflammation mediators, inhibit the production of pro-apoptosis protein including caspase-3, caspase-9 and Bax, decrease the expression of autophagy-linked protein including Beclin-1 and LC3, increase anti-apoptosis protein Bcl-2, and restrain the activation of ERK and PPARγ.

CONCLUSION

Cafestol preconditioning could attenuate inflammatory response, apoptosis and autophagy on hepatic ischemia reperfusion injury by suppressing ERK/PPARγ pathway.

Transient Expression of Reck Under Hepatic Ischemia/Reperfusion Conditions Is Associated with Mapk Signaling Pathways

In this study, we demonstrated the involvement of matrix metalloproteinases (MMPs) in hepatic ischemia/reperfusion (I/R) injury. Our aim is to evaluate the impact of reperfusion on I/R-related changes in RECK, an MMP modulator, and mitogen-activated protein kinase (MAPKs) pathways (ERK, p38, and JNK). Male Wistar rats were either subjected to 60 min partial-hepatic ischemia or sham-operated. After a 60 min or 120 min reperfusion, liver samples were collected for analysis of MMP-2 and MMP-9 by zymography and RECK, TIMP-1, and TIMP-2 content, MAPKs activation (ERK1/2, JNK1/2, and p38), as well as iNOS and eNOS by Western blot. Serum enzymes AST, ALT, and alkaline-phosphatase were quantified. A transitory decrease in hepatic RECK and TIMPs was associated with a transitory increase in both MMP-2 and MMP-9 activity and a robust activation of ERK1/2, JNK1/2, and p38 were detected at 60 min reperfusion. Hepatic expression of iNOS was maximally upregulated at 120 min reperfusion. An increase in eNOS was detected at 120 min reperfusion. I/R evoked significant hepatic injury in a time-dependent manner. These findings provide new insights into the underlying molecular mechanisms of reperfusion in inducing hepatic injury: a transitory decrease in RECK and TIMPs and increases in both MAPK and MMP activity suggest their role as triggering factors of the organ dysfunction.

TGF-β/Smad and JAK/STAT pathways are involved in the anti-fibrotic effects of propylene glycol alginate sodium sulphate on hepatic fibrosis

Liver fibrosis, a consequence of unhealthy modern lifestyles, has a growing impact on human health, particularly in developed countries. Here, we have explored the anti-fibrotic effects of propylene glycol alginate sodium sulphate (PSS), a natural extract from brown algae, in fibrotic mice and cell models. Thus, we established bile duct ligature and carbon tetrachloride mouse models and LX-2 cell models with or without PSS treatment. Liver pathological sections and the relevant indicators in serum and liver tissues were examined. PSS prevented hepatic injury and fibrosis to a significant extent, and induced up-regulation of matrix metalloproteinase-2 and down-regulation of tissue inhibitor of metalloproteinase-1 through suppressing the transforming growth factor β1 (TGF-β1)/Smad pathway. PSS additionally exerted an anti-autophagy effect through suppressing the Janus kinase (JAK) 2/transducer and activator of transcription 3 (STAT3) pathway. In conclusion, PSS prevents hepatic fibrosis by suppressing inflammation, promoting extracellular matrix (ECM) decomposition and inactivating hepatic stellate cells through mechanisms involving the TGF-β1/Smad2/3 and JAK2/STAT3 pathways in vivo and in vitro.

Helicobacter hepaticus infection induces chronic hepatitis and fibrosis in male BALB/c mice via the activation of NF-κB, Stat3, and MAPK signaling pathways

BACKGROUND

It has been documented that Helicobacter hepaticus (H hepaticus) infection is linked to chronic hepatitis and liver cancer. However, our understanding of the molecular mechanisms underlying progression of the H hepaticus-induced hepatic inflammation to cellular hepatocarcinoma is still limited.

MATERIALS AND METHODS

In our study, male BALB/c mice were infected by H hepaticus for 8, 12, 16, 20, and 24 weeks. Histopathology, H hepaticus colonization dynamics, select signaling pathways, and expression of key inflammatory cytokines in the liver were examined.

RESULTS

We found that H hepaticus was detectible in feces of mice at 7 days postinfection (DPI) by PCR, but it was not detected in the livers by PCR until 8 weeks postinfection (WPI). In addition, abundance of colonic and hepatic H hepaticus was progressively increased over the infection duration. H hepaticus-induced hepatic inflammation and fibrosis were aggravated over the infection duration, and necrosis or cirrhosis developed in the infected liver at 24 WPI H hepaticus infection increased levels of alanine aminotransferase and aspartate aminotransferase. Moreover, mRNA levels of Il-6 and Tnf-α were significantly elevated in the livers of H hepaticus-infected mice compared to uninfected control from 8 WPI to 24 WPI. Furthermore, Stat3, nuclear factor-κB (p65), and MAPK (Erk1/2 and p38) were activated by H hepaticus infection.

CONCLUSIONS

These data demonstrated that male BALB/c mice can be used as a new mouse model of H hepaticus-induced liver diseases and that the H hepaticus-induced liver injury is triggered by NF-κB, Jak-Stat, and MAPK signaling pathways.

Helicobacter hepaticus infection-induced IL-33 promotes hepatic inflammation and fibrosis through ST2 signaling pathways in BALB/c mice

It has been documented that Helicobacter hepaticus (H. hepaticus) infection is linked to hepatic inflammation and fibrosis. Interleukin 33 (IL-33) is a cytokine involved in inflammatory and fibrotic diseases, but its relevance to H. hepaticus infection-induced liver inflammation and fibrosis is unknown. In this study, we found that the expression of IL-33 in mice liver was significantly induced by H. hepaticus infection at 24 weeks post infection (WPI). Immunohistochemistry analysis revealed that IL-33 was transferred from the nucleus to the cytoplasm due to infection. The quantitation of inflammatory cytokine and histopathology evaluation showed that IL-33 knockdown attenuated the H. hepaticus-induced hepatic inflammation and fibrosis. More importantly, H. hepaticus promoted the expression of the IL-33 receptor ST2 on cell surfaces, and the expression of ST2 then activated the expression nuclear factor-κB (p65), α-SMA, and Erk1/2. These observations provide novel insights into the pathogenic mechanism of hepatic inflammation and fibrosis during H. hepaticus infection.

Effects and mechanisms of PSS-loaded nanoparticles on coronary microcirculation dysfunction in streptozotocin-induced diabetic cardiomyopathy rats

Coronary microvascular dysfunction (CMD) is the pathological basis and pathogenesis of diabetic cardiomyopathy (DCM). Propylene glycol alginate sodium sulfate (PSS) as heparinoid drug has many biological activities. Here, a novel PSS-loaded nanoparticle (PSS-NP) was prepared to study its effect on the CMD of DCM. We used diabetes mellitus rat induced by STZ to establish the CMD model of DCM, and the study was detected by echocardiography, histological analysis, transmission electron microscopy, immunofluorescence staining, enzyme-linked immunosorbent assay, real time-PCR analysis, liquid-chip analysis, western blot analysis and so on. The experimental results suggested that PSS-NP could improve the survival state of rats, cardiac function, myocardial morphology and coronary microcirculation structure disorders, and increase the number of microvessels. In addition, we demonstrated that PSS-NP could alleviate the CMD by improving endothelial function, anticoagulation and antioxidative stress. The outcomes of this study provided new treatment thoughts for the therapy of coronary microcirculation dysfunction in DCM.

Propylene glycol alginate sodium sulphate attenuates LPS-induced acute lung injury in a mouse model

Propylene glycol alginate sodium sulphate, a sulphated polysaccharide, has been used to treat hyperlipidaemia and ischaemia–reperfusion injury of liver. This study aimed to investigate the effect of propylene glycol alginate sodium sulphate on LPS-induced acute lung injury. Propylene glycol alginate sodium sulphate was injected intraperitoneally into male C57BL/6 mice with or without LPS administration. Survival rates were calculated. Serum, bronchoalveolar lavage fluid and lung tissues were collected to determine lung histology, wet/dry ratio, Evans blue albumin permeability, protein levels, the counts of immune cells and the levels of inflammatory cytokines and chemokines. Serum alanine aminotransferase, aspartate transaminase, creatinine and blood urea nitrogen levels were also measured. Additionally, NF-κB signalling was detected in the lung. Propylene glycol alginate sodium sulphate treatment significantly improved the survival of mice suffering from LPS. Lung histological injury, wet/dry ratio, Evans blue albumin permeability, neutrophils and the inflammatory cytokines and chemokines were significantly reduced by propylene glycol alginate sodium sulphate treatment. NF-κB signalling was significantly inhibited by propylene glycol alginate sodium sulphate in the lung of mice subjected to LPS. Furthermore, serum alanine aminotransferase, aspartate transaminase, creatinine and blood urea nitrogen levels were also significantly decreased after propylene glycol alginate sodium sulphate administration. This study suggests that NF-κB signalling and inhibition of pro-inflammatory cytokines, chemokines and neutrophil accumulation may be involved in the process of acute lung injury attenuation by propylene glycol alginate sodium sulphate.

Role of the Extracellular Signal-Regulated Kinase 1/2 Signaling Pathway in Ischemia-Reperfusion Injury

Extracellular signal-regulated kinase 1/2 (ERK_1/2), an important member of the mitogen-activated protein kinase family, is found in many organisms, and it participates in intracellular signal transduction. Various stimuli induce phosphorylation of ERK_1/2 in vivo and in vitro. Phosphorylated ERK_1/2 moves to the nucleus, activates many transcription factors, regulates gene expression, and controls various physiological processes, finally inducing repair processes or cell death. With the aging of the population around the world, the occurrence of ischemia-reperfusion injury (IRI), especially in the brain, heart, kidney, and other important organs, is becoming increasingly serious. Abnormal activation of the ERK_1/2 signaling pathway is closely related to the development and the metabolic mechanisms of IRI. However, the effects of this signaling pathway and the underlying mechanism differ between various models of IRI. This review summarizes the ERK_1/2 signaling pathway and the molecular mechanism underlying its role in models of IRI in the brain, heart, liver, kidneys, and other organs. This information will help to deepen the understanding of ERK_1/2 signals and deepen the exploration of IRI treatment based on the ERK_1/2 study.

The protective effect of the TUG1/miR‑197/MAPK1 axis on lipopolysaccharide‑induced podocyte injury

The podocyte, a type of glomerular epithelial cell, is the key constituent of the filtration barrier layer in the kidney. Previous studies have shown that long non‑coding RNA (lncRNA)‑taurine‑upregulated gene 1 (TUG1) served a protective role in diabetes‑induced podocyte damage. The aim of the present study was to investigate the potential role of TUG1 in the progress of podocyte injury induced by lipopolysaccharide (LPS), and explore the underlying mechanisms. The results showed that TUG1 expression was suppressed in LPS‑induced podocytes. Enhanced TUG1 expression by exogenous recombinant vector regulated the expression of podocyte associated proteins [Nephrin, Podocin and CCAAT/enhancer‑binding protein (CHOP)]. A marked decrease was observed in the level the albumin influx in cells transfected with TUG1. Further study indicated that microRNA (miR)‑197 is a potential target of TUG1. The enhanced level of miR‑197 induced by LPS was inhibited in cells transfected with TUG1. The decreased Nephrin and Podocin expression, upregulated CHOP expression and the increased albumin influx were slightly enhanced by miR‑197 mimic transfection, while markedly suppressed by miR‑197 inhibitor transfection in LPS‑induced podocytes. Mitogen‑activated protein kinase (MAPK) protein was predicted as a potential target of miR‑197. The downregulated expression of phosphorylated‑MAPK/MAPK induced by LPS was significantly suppressed by TUG1 transfection in podocytes. In addition to this, autophagy was promoted by TUG1 transfection via the elevation of the Beclin1 and light chain (LC)3 II/LC3 I levels, and suppressing p62 expression. However, the p38 MAPK inhibitor SB203580 reversed the changes that TUG1 induced in the levels of Beclin1, LC3 II/LC3 I and p62. Taken together, these results demonstrated that LPS‑induced podocyte injury could be alleviated by the TUG1/miR‑197/MAPK1 axis.

Mitogen Activated Protein Kinases in Steatotic and Non-Steatotic Livers Submitted to Ischemia-Reperfusion

: We analyzed the participation of mitogen-activated protein kinases (MAPKs), namely p38, JNK and ERK 1/2 in steatotic and non-steatotic livers undergoing ischemia-reperfusion (I-R), an unresolved problem in clinical practice. Hepatic steatosis is a major risk factor in liver surgery because these types of liver tolerate poorly to I-R injury. Also, a further increase in the prevalence of steatosis in liver surgery is to be expected. The possible therapies based on MAPK regulation aimed at reducing hepatic I-R injury will be discussed. Moreover, we reviewed the relevance of MAPK in ischemic preconditioning (PC) and evaluated whether MAPK regulators could mimic its benefits. Clinical studies indicated that this surgical strategy could be appropriate for liver surgery in both steatotic and non-steatotic livers undergoing I-R. The data presented herein suggest that further investigations are required to elucidate more extensively the mechanisms by which these kinases work in hepatic I-R. Also, further researchers based in the development of drugs that regulate MAPKs selectively are required before such approaches can be translated into clinical liver surgery.

Gene Expression Profiling in Ischemic Postconditioning to Alleviate Mouse Liver Ischemia/Reperfusion Injury

Ischemic postconditioning (IPO) attenuates hepatic ischemia/reperfusion (I/R) injury. However, little is known about the underlying biological pathophysiology, which could be, at least in part, informed by exploring the transcriptomic changes using next-generation RNA sequencing (RNA-Seq). In this study, 18 mice (C57BL/6) were involved and randomly assigned to three groups: normal (n=6), I/R (n=6, subjected to 70% hepatic I/R), and IR+IPO (n=6, applying IPO to mice with I/R injury). We randomly selected 3 mice per group and extracted their liver tissues for next-generation RNA-Seq. We performed a bioinformatics analysis for two comparisons: normal vs. I/R and I/R vs. IR+IPO. From the analysis, 2416 differentially expressed genes (DEGs) were identified (p < 0.05 and fold change ≥ 1.5). Gene ontology (GO) analysis revealed that these genes were mainly related to cellular metabolic processes, nucleic acids and protein binding processes. The enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for the DEGs were the mitogen-activated protein kinase (MAPK), IL-17 signalling pathway, regulating pluripotency of stem cells, and insulin resistance pathway. Validation of 12 selected DEGs by qRT-PCR showed that Cyr61, Atf3, Nr4a1, Gdf15, Osgin1, Egr1, Epha2, Dusp1, Dusp6, Gadd45a and Gadd45b were significantly amplified. Finally, a protein-protein interaction (PPI) network constructed to determine interactions of these 11 DEGs. In summary, by exploring gene expression profiling in regard to hepatic I/R and IPO using next-generation RNA-Seq, we suggested a few progression-related genes and pathways, providing some clues for future experimental research.

Hepatoprotective Effect of Baicalein Against Acetaminophen-Induced Acute Liver Injury in Mice

Baicalein (BAI), one of the main components of Scutellaria baicalensis Georgi, possesses numerous pharmacological properties, including anti-cancer, anti-oxidative, anti-virus and anti-bacterial activities. The purpose of this study was to evaluate the hepatoprotective effect of baicalein against acetaminophen (APAP)-exposed liver injury in mice, and elucidate the underlying hepatoprotective mechanism. Baicalein pretreatment significantly alleviated the elevation of IL-6, IL-1β and TNF-α in serum and hepatic in a dose-dependent manner. It also dose-dependently reduced the hepatic malondialdehyde (MDA) concentration, as well as the depletion of hepatic superoxide dismutase (SOD), hepatic glutathione (GSH) and hepatic catalase (CAT). Moreover, pretreatment with baicalein significantly ameliorated APAP-exposed liver damage and histological hepatocyte changes. Baicalein also relieved APAP-induced autophagy by regulating AKT/mTOR pathway, LC3B and P62 expression. Furthermore, the hepatoprotective effect of baicalein to APAP-induced liver injury involved in Jak2/Stat3 and MAPK signaling pathway. Taken together, our findings suggested that baicalein exhibits the ability to prevent liver from APAP-induced liver injury and provided an underlying molecular basis for potential applications of baicalein to cure liver injuries.

Beraprost sodium preconditioning prevents inflammation, apoptosis, and autophagy during hepatic ischemia-reperfusion injury in mice via the P38 and JNK pathways

OBJECTIVE

The goal of this study was to determine the effects of beraprost sodium (BPS) preconditioning on hepatic ischemia-reperfusion (IR) injury and its underlying mechanisms of action.

MATERIALS AND METHODS

Mice were randomly divided into sham, IR, IR+BPS (50 µg/kg), and IR+BPS (100 µg/kg) groups. Saline or BPS was given to the mice by daily gavage for 1 week before the hepatic IR model was established. Liver tissues and orbital blood were collected at 2, 8, and 24 hours after reperfusion for the determination of liver enzymes, inflammatory mediators, apoptosis- and autophagy-related proteins, key proteins in P38 and c-Jun N-terminal kinase (JNK) cascades, and evaluation of liver histopathology.

RESULTS

BPS preconditioning effectively reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, improved pathological damage, ameliorated production of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), and affected expressions of Bax, Bcl-2, Caspase-3, Caspase-8, and Caspase-9, microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, and P62. The protective effects of BPS preconditioning were associated with reduced P38 and JNK phosphorylation.

CONCLUSION

BPS preconditioning ameliorated hepatic IR injury by suppressing inflammation, apoptosis, and autophagy, partially via inhibiting activation of the P38 and JNK cascades.

Novel dihydroartemisinin derivative DHA-37 induces autophagic cell death through upregulation of HMGB1 in A549 cells

Dihydroartemisinin (DHA) and its analogs are reported to possess selective anticancer activity. Here, we reported a novel DHA derivative DHA-37 that exhibited more potent anticancer activity on the cells tested. Distinct from DHA-induced apoptosis, DHA-37 triggered excessive autophagic cell death, and became the main contributor to DHA-37-induced A549 cell death. Incubation of the cells with DHA-37 but not DHA produced increased dots distribution of GFP-LC3 and expression ratio of LC3-II/LC3-I, and enhanced the formation of autophagic vacuoles as revealed by TEM. Treatment with the autophagy inhibitor 3-MA, LY294002, or chloroquine could reverse DHA-37-induced cell death. In addition, DHA-37-induced cell death was associated significantly with the increased expression of HMGB1, and knockdown of HMGB1 could reverse DHA-37-induced cell death. More importantly, the elevated HMGB1 expression induced autophagy through the activation of the MAPK signal but not PI3K-AKT–mTOR pathway. In addition, DHA-37 also showed a wonderful performance in A549 xenograft mice model. These findings suggest that HMGB1 as a target candidate for apoptosis-resistant cancer treatment and artemisinin-based drugs could be used in inducing autophagic cell death.

Marine Carbohydrate-Based Compounds with Medicinal Properties

The oceans harbor a great diversity of organisms, and have been recognized as an important source of new compounds with nutritional and therapeutic potential. Among these compounds, carbohydrate-based compounds are of particular interest because they exhibit numerous biological functions associated with their chemical diversity. This gives rise to new substances for the development of bioactive products. Many are the known applications of substances with glycosidic domains obtained from marine species. This review covers the structural properties and the current findings on the antioxidant, anti-inflammatory, anticoagulant, antitumor and antimicrobial activities of medium and high molecular-weight carbohydrates or glycosylated compounds extracted from various marine organisms.

Circular RNAs are differentially expressed in liver ischemia/reperfusion injury model

Liver ischemia/reperfusion (I/R) injury has high mortality due to the intense inflammatory process occurs in the liver. However, the pathological mechanism underlying I/R injury is still not clear. Recent works showed that circular RNAs play critical roles in many human diseases. In this study, the occurrence of liver I/R injury was validated by an analysis of the blood samples and hematoxylin-eosin (HE) staining of liver tissues. Total RNA was purified and followed by RNA-seq in the purpose of screening the circRNAs in significant differentially expression, which were validated by quantitative PCR. GO and KEGG analysis were performed to determine the function of these differentially expressed circular RNAs. The circular structure of the circRNA was validated with gel electrophoresis and RNase R treatment. We found that some circular RNAs were differentially expressed in Liver I/R mouse models through bioinformatics analysis. These circular RNAs play roles in biological process, cellular component, and molecular function through GO analysis. Meanwhile, Hippo signaling pathway was found to be correlated with circular RNAs function in I/R models by KEGG analysis. To further validate bioinformatics data, two up-regulated and three down-regulated circular RNAs were confirmed in I/R models. The circularity of these differentially expressed circular RNAs was validated through gel electrophoresis and RNase R treatment. In summary, this work provides new insights into the mechanism underlying pathogenesis of liver I/R injury, providing new and potentially efficient targets against I/R injury.