Protective effects of crocin and zinc sulfate on hepatic ischemia-reperfusion injury in rats: a comparative experimental model study

Crocin suppresses breast cancer cell proliferation by down-regulating tumor promoter miR-122-5p and up-regulating tumor suppressors FOXP2 and SPRY2

Crocin has been reported to have antitumor activity in several tumors including breast cancer. Nevertheless, the mechanism of action of crocin on breast cancer remains unclear. The cytotoxicity of crocin was evaluated by CCK-8 assay. Cell proliferation was assessed using EdU incorporation assay and western blot analysis. Breast cancer-related genes were extracted from GEPIA. miR-122-5p targets were predicted using Targetscan, starbase, and miRDB softwares. Luciferase reporter assay was employed to confirm whether miR-122-5p targeted sprouty2 (SPRY2) and forkhead box P2 (FOXP2). Results showed that crocin exhibited cytotoxicity and suppressed the proliferation in breast cancer cells. miR-122-5p was upregulated in breast cancer tissues and cells. Crocin suppressed miR-122-5p to block the proliferation of breast cancer cells. Seven targets of miR-122-5p were identified in breast cancer. SPRY2 and FOXP2 were selected for further experiments due to their involvement in breast cancer. miR-122-5p targeted SPRY2 and FOXP2 to inhibit their expression. miR-122-5p knockdown restrained breast cancer cell proliferation by targeting SPRY2 and FOXP2. Additionally, crocin increased SPRY2 and FOXP2 expression by inhibiting miR-122-5p expression. Together, our results suggested that crocin inhibited proliferation of breast cancer cells through decreasing miR-122-5p expression and the subsequent increase of SPRY2 and FOXP2 expression.

Research progress of lncRNA and miRNA in hepatic ischemia-reperfusion injury

BACKGROUND

Hepatic ischemia-reperfusion injury (HIRI) is a common complication of liver surgeries, such as hepatectomy and liver transplantation. In recent years, several non-coding RNAs (ncRNAs) including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been identified as factors involved in the pathological progression of HIRI. In this review, we summarized the latest research on lncRNAs, miRNAs and the lncRNA-miRNA regulatory networks in HIRI.

DATA SOURCES

The PubMed and Web of Science databases were searched for articles published up to December 2021 using the following keywords: "hepatic ischemia-reperfusion injury", "lncRNA", "long non-coding RNA", "miRNA" and "microRNA". The bibliography of the selected articles was manually screened to identify additional studies.

RESULTS

The mechanism of HIRI is complex, and involves multiple lncRNAs and miRNAs. The roles of lncRNAs such as AK139328, CCAT1, MALAT1, TUG1 and NEAT1 have been established in HIRI. In addition, numerous miRNAs are associated with apoptosis, autophagy, oxidative stress and cellular inflammation that accompany HIRI pathogenesis. Based on the literature, we conclude that four lncRNA-miRNA regulatory networks mediate the pathological progression of HIRI. Furthermore, the expression levels of some lncRNAs and miRNAs undergo significant changes during the progression of HIRI, and thus are potential prognostic markers and therapeutic targets.

CONCLUSIONS

Complex lncRNA-miRNA-mRNA networks regulate HIRI progression through mutual activation and antagonism. It is necessary to screen for more HIRI-associated lncRNAs and miRNAs in order to identify novel therapeutic targets.

Crocins for Ischemic Stroke: A Review of Current Evidence

Crocins (CRs) and the related active constituents derived from Crocus sativus L. (Saffron) have demonstrated protective effects against cerebral ischemia and ischemic stroke, with various bioactivities including neuroprotection, anti-neuroinflammation, antioxidant, and cardiovascular protection. Among CRs, crocin (CR) has been shown to act on multiple mechanisms and signaling pathways involved in ischemic stroke, including mitochondrial apoptosis, nuclear factor kappa light chain enhancer of B cells pathway, S100 calcium-binding protein B, interleukin-6 and vascular endothelial growth factor-A. CR is generally safe and well-tolerated. Pharmacokinetic studies indicate that CR has poor bioavailability and needs to convert to crocetin (CC) in order to cross the blood-brain barrier. Clinical studies have shown the efficacy of saffron and CR in treating various conditions, including metabolic syndrome, depression, Alzheimer’s disease, and coronary artery disease. There is evidence supporting CR as a treatment for ischemic stroke, although further studies are needed to confirm their efficacy and safety in clinical settings.

Novel Targets and Therapeutic Strategies to Protect Against Hepatic Ischemia Reperfusion Injury

Hepatic ischemia reperfusion injury (IRI), a fascinating topic that has drawn a lot of interest in the last few years, is a major complication caused by a variety of clinical situations, such as liver transplantation, severe trauma, vascular surgery, and hemorrhagic shock. The IRI process involves a series of complex events, including mitochondrial deenergization, metabolic acidosis, adenosine-5'-triphosphate depletion, Kupffer cell activation, calcium overload, oxidative stress, and the upregulation of pro-inflammatory cytokine signal transduction. A number of protective strategies have been reported to ameliorate IRI, including pharmacological therapy, ischemic pre-conditioning, ischemic post-conditioning, and machine reperfusion. However, most of these strategies are only at the stage of animal model research at present, and the potential mechanisms and exact therapeutic targets have yet to be clarified. IRI remains a main cause of postoperative liver dysfunction, often leading to postoperative morbidity or even mortality. Very recently, it was reported that the activation of peroxisome proliferator-activated receptor γ (PPARγ), a member of a superfamily of nuclear transcription factors activated by agonists, can attenuate IRI in the liver, and FAM3A has been confirmed to mediate the protective effect of PPARγ in hepatic IRI. In addition, non-coding RNAs, like LncRNAs and miRNAs, have also been reported to play a pivotal role in the liver IRI process. In this review, we presented an overview of the latest advances of treatment strategies and proposed potential mechanisms behind liver IRI. We also highlighted the role of several important molecules (PPARγ, FAM3A, and non-coding RNAs) in protecting against hepatic IRI. Only after achieving a comprehensive understanding of potential mechanisms and targets behind IRI can we effectively ameliorate IRI in the liver and achieve better therapeutic effects.

Umbelliferone alleviates hepatic ischemia/reperfusion-induced oxidative stress injury via targeting Keap-1/Nrf-2/ARE and TLR4/NF-κB-p65 signaling pathway

Umbelliferone (UMB; 7-hydroxycoumarin) is a natural compound that exhibited a diversity of pharmacological activities. Its protective effects against various ischemia/reperfusion (IR) injuries, including heart, kidney, and testis, have been observed. However, their effect on hepatic IR is still not investigated yet. Here, this study was conducted to examine the potential protective role of UMB during the early phase of hepatic IR injury via targeting Keap-1/Nrf-2/ARE and its closely related signaling pathway, TLR4/NF-κB-p65. Experimentally, forty Wistar albino rats were randomly divided into 4 groups: Sham control group (received 1% carboxymethyl cellulose as a vehicle), UMB group (30 mg/kg/day, P.O.), IR group (subjected to complete hepatic IR injury), and IR + UMB group. Our results revealed that oral UMB effectively reduced the serum levels of ALT, AST, ALP, and LDH along with the restoration of oxidant/antioxidant status. At the molecular level, UMB markedly activated Nrf-2 expression and its down-streaming targets: HO-1, NQO1, GCLC, SOD3, and TNXRD1, along with Keap-1 down-regulation. Besides, UMB significantly down-regulated NF-κB-p65 and TLR4 expressions with subsequent decreased TNF-α and IL-1β levels coupled with the up-regulation of the IL-10 level. Finally, biochemical findings were confirmed by attenuation of histopathological changes in liver tissues. Together, UMB is a promising agent for the amelioration of liver tissues against IR-induced oxidative injury through activation of the Keap-1/Nrf-2/ARE signaling pathway along with suppression of its closely related signaling pathways: TLR4/NF-κB-p65. Illustrated diagram explored the prospective underlying protective mechanism of UMB against IR-induced hepatic damage.

Protective effects of crocin on testicular torsion/detorsion in rats

Oxidative stress, caused by extreme accumulation of un-scavenged reactive oxygen species, plays an integral role in the Ischemia-Reperfusion (I/R) injury to the testicles following testicular torsion. The current research aimed to examine the protective effects of crocin as a natural antioxidant on testicular I/R injury in rats. Animals were divided randomly into five groups (seven each): (1) sham group, (2) torsion/detorsion (T/D) group, (3) intact group with 100 mg/kg crocin, (4) and (5) T/D groups followed by treatment with two different doses of crocin (50 and 100 mg/kg (IP)). I/R injury was induced by 720° clockwise torsion of the left testicles for 2 h. After 24 h of reperfusion, blood samples and epididymal sperms were collected to measure biochemical (GPx, SOD, and MDA), hormonal (testosterone), and sperm parameters (total sperm recovery, motility, viability, and morphology). Moreover, affected testicles were subjected to histopathology examination. I/R injury caused a significant reduction in sperm characteristics (except for morphology) (P < 0.05), which could not be significantly improved by crocin administration at either dose (P > 0.05). Johnsen's testicular score, mean seminiferous tubular diameter, and germinal epithelial cell thickness were significantly decreased in the T/D group compared to the intact and sham groups. However, crocin could significantly improve the histopathological parameters in both treatment groups compared to the T/D group (P < 0.05). T/D reduced SOD and GPx activity and testosterone level significantly (except for GPx) compared to the sham group (P < 0.05). However, crocin administration could significantly reverse them. Also, crocin reduced the amount of MDA significantly in the high-dose treatment group in comparison to T/D group (P < 0.05). The results of the current study revealed that crocin could be a promising agent to protect against I/R injury following surgical correction of the testicular torsion.

Mitochondrial Targeting Therapy Role in Liver Transplant Preservation Lines: Mechanism and Therapeutic Strategies

The normal function of mitochondria in the hepatic parenchyma can be disrupted by ischemia/reperfusion (I/R) damage during liver transplantation. The pathology of these insults involves various cellular and molecular steps of events that have been extensively researched over decades but are yet to provide complete answers. This review discusses the brief mechanism of the pathophysiology following ischemia/reperfusion injury (IRI) and various targeting strategies that could result in improved graft function.

The traditional treatment for end-stage liver disease i.e., liver transplantation, has been complicated by I/R damage. The poor graft function or primary non-function found after liver transplantation may be due to mitochondrial dysfunction following IRI. As a result, determining the sequence of incidents that cause human hepatic mitochondrial dysfunction is crucial; it might contribute to further improvements in the outcome of liver transplantation. Early discovery of novel prognostic factors involved in IRI could serve as a primary endpoint for predicting the outcome of liver grafts as well as promoting the early implementation of novel IRI-prevention strategies. In this review, recent developments in the study of mitochondrial dysfunction and I/R damage are discussed, specifically those concerning liver transplantation. Furthermore, we also explore different pharmacological therapeutic methods that may be used and their connections to mitochondrion-related processes and goals.

Although significant progress has been made in our understanding of IRI and mitochondrial dysfunction, further research is needed to elucidate the cellular and molecular pathways underlying these processes to help identify biomarkers that can aid donor organ evaluation.

Crocins: A comprehensive review of structural characteristics, pharmacokinetics and therapeutic effects

Crocins, as a kind of water-soluble carotenoid pigment, are a series of ester compounds formed from crocetin and gentibiose or glucose, and mainly distributed among Crocus sativus L. (CSL), Gardenia jasminoides Ellis. (GJE). Crocins exhibit a wide range of pharmacological effects on neurodegeneration, cardiovascular disease, cerebrovascular disease, depression, liver disease, arthritis, tumor, diabetes, etc. This review systematically discussed the pharmacologic study of crocins in the aspect of structural characteristic and pharmacokinetics, and summarized the mechanism of treating disease. It summarized the abundant research of crocins from 1984 to 2020 based on the above aspects, which provide a reference for the deeply development and application of crocins.

Hepatic ischemia reperfusion injury: effect of moderate intensity exercise and oxytocin compared to l-arginine in a rat model

Background

Hepatic ischemia reperfusion (IR) injury is considered as a main cause of liver damage and dysfunction. The l-arginine/nitric oxide pathway seems to be relevant during this process of IR. Although acute intense exercise challenges the liver with increased reactive oxygen species (ROS), regular training improves hepatic antioxidant status. Also, oxytocin (Oxy), besides its classical functions, it exhibits a potent antistress, anti-inflammatory, and antioxidant effects. This study was designed to evaluate the hepatic functional and structural changes induced by hepatic IR injury in rats and to probe the effect and potential mechanism of moderate intensity exercise training and/or Oxy, in comparison to a nitric oxide donor, l-arginine, against liver IR-induced damage.

Results

Compared to the sham-operated control group, the hepatic IR group displayed a significant increase in serum levels of ALT and AST, plasma levels of MDA and TNF-α, and significant decrease in plasma TAC and nitrite levels together with the worsening of liver histological picture. L-Arg, Oxy, moderate intensity exercise, and the combination of both Oxy and moderate intensity exercises ameliorated these deleterious effects that were evident by the significant decrease in serum levels of ALT and AST, significant elevation in TAC and nitrite, and significant decline in lipid peroxidation (MDA) and TNF-α, besides regression of histopathological score regarding hepatocyte necrosis, vacuolization, and nuclear pyknosis. Both the moderate intensity exercise-trained group and Oxy-treated group showed a significant decline in TNF-α and nitrite levels as compared to l-Arg-treated group. The Oxy-treated group showed statistical insignificant changes in serum levels of ALT, AST, and plasma levels of nitrite, MDA, TAC, and TNF-α as compared to moderate intensity exercise-trained group.

Conclusion

The combination of both moderate intensity exercise and Oxy displayed more pronounced hepatoprotection on comparison with l-Arg which could be attributed to their more prominent antioxidant and anti-inflammatory effects but not due to their NO-enhancing effect.

MicroRNA mediated regulation of the major redox homeostasis switch, Nrf2, and its impact on oxidative stress-induced ischemic/reperfusion injury

Ischemia/reperfusion injury (IRI) initiates from oxidative stress caused by lack of blood supply and subsequent reperfusion. It is often associated with sterile inflammation, cell death and microvascular dysfunction, which ultimately results in myocardial, cerebral and hepatic IRIs. Reportedly, deregulation of Nrf2 pathway plays a significant role in the oxidative stress-induced IRIs. Further, microRNAs (miRNAs/miRs) are proved to regulate the expression and activation of Nrf2 by targeting either the 3'-UTR or the upstream regulators of Nrf2. Additionally, compounds (crocin, ZnSO4 and ginsenoside Rg1) that modulate the levels of the Nrf2-regulating miRNAs were found to exhibit a protective effect against IRIs of different organs. Therefore, the current review briefs the impact of ischemia reperfusion (I/R) pathogenesis in various organs, role of miRNAs in the regulation of Nrf2 and the I/R protective effect of compounds that alter their expression.

Targeting autophagy to modulate hepatic ischemia/reperfusion injury: A comparative study between octreotide and melatonin as autophagy modulators through AMPK/PI3K/AKT/mTOR/ULK1 and Keap1/Nrf2 signaling pathways in rats

Hepatic ischemia-reperfusion (HIR) injury is a common pathophysiological process in many clinical settings. This study was designed to compare the protective role of octreotide (somatostatin analogue, OCT) and melatonin (N-acetyl-5-methoxytryptamine, MLT) through the modulation of autophagy against HIR injury in rats. Male albino rats were divided into sham, HIR, OCT at three doses (50, 75, and 100 μg/kg), MLT, MLT + OCT75, compound C (AMPK inhibitor, CC), and CC + OCT75 groups. Ischemia was induced for 30 min followed by 24 h reperfusion. Biochemical, histopathological, immunohistochemical, lipid peroxidation, ELISA, qPCR, and western blot techniques were performed in our study. Liver autophagy was restored by OCT at doses (50 or 75 μg/kg) as indicated by elevating the expressions of Beclin-1, ATG7, and LC3 accompanied by the reduction of p62 expression through induction of AMPK/S317-ULK1 and inhibition of PI3K/AKT/mTOR/S757-ULK1 signaling pathways. As well, OCT maintained the integrity of the Keap1-Nrf2 system for the normal hepatic functions via controlling the Keap1 turnover through autophagy in a p62-dependent manner, resulting in upholding a series of anti-oxidant and anti-inflammatory cascades. These effects were abolished by compound C. On the other hand, MLT showed a decrease in the autophagy markers via inhibiting AMPK/pS317-ULK1 and activating PI3K/AKT/mTOR/pS757-ULK1 pathways. Autophagy inhibition with MLT markedly reversed the hepatoprotective effects of OCT75 after HIR injury. Finally, our results proved for the first time that OCT75 was more effective than MLT as it was sufficient to induce protective autophagy in our HIR model, which led to the induction of Nrf2-dependent AMPK/autophagy pathways.

Octreotide and melatonin alleviate inflammasome-induced pyroptosis through inhibition of TLR4-NF-κB-NLRP3 pathway in hepatic ischemia/reperfusion injury

BACKGROUND AND AIM

The Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB)/NLRP3 inflammasome signaling pathway is essential in the pathogenesis of hepatic ischemia/ reperfusion (HIR) injury. Pyroptosis is a proinflammatory programmed cell death that is related to several diseases. Thus, the purpose of this study was to examine whether pretreatment with octreotide (somatostatin analogue, OCT) at different doses or OCT at 75μg/kg combined with melatonin (N-acetyl-5-methoxytryptamine, MLT) can alleviate HIR injury via targeting NLRP3 inflammasome-induced pyroptosis in a TLR4/MyD88/NF-κB dependent manner.

METHODS

Rats were randomized into sham, HIR, OCT (50, 75, and 100 µg/kg), MLT, and MLT + OCT75 groups. Ischemia was induced via occlusion of the portal triad for 30 min followed by 24 h reperfusion.

RESULTS

OCT pretreatment at doses (50 or 75 μg/kg), MLT alone, and MLT + OCT75 significantly ameliorated the biochemical with histopathological changes, oxidative stress, inflammation, apoptosis, then augmented anti-oxidant and anti-apoptotic markers through downregulation of HMGB1, TLR4, MyD88, TRAF-6, p-IκBα (S32), p-NF-κBp65 (S536), NLRP3, ASC, caspase-1(p20), and GSDMD-N expressions compared with HIR group.

CONCLUSION

OCT at doses (50 or 75 µg/kg) showed for the first time a hepatoprotective effect against HIR injury via inhibiting TLR4-NLRP3-mediated pyroptosis in rats. As well, OCT75 was more effective than OCT50 or MLT alone, and its effect was not enhanced after the addition of MLT, through downregulation of TLR4/MyD88/NF-κB/NLRP3 inflammasome pathway.

Use of natural anti-oxidants in experimental animal models of hepatic ischemia-reperfusion injury

Background

Ischemia-reperfusion injury (IRI) remains a clinical challenge in liver surgery, trauma and transplantation, contributing to morbidity and mortality worldwide. Thus, its impact, not only on the liver itself but also on remote tissues, has been studied during the last years. Different natural anti-oxidant substances have been researched in animal models, implementing different times of ischemia, aiming to test new therapeutic interventions.

Objective

A literature review has been conducted with two goals: (1) to identify different natural anti-oxidants studied in experimental models; and (2) to summarize the various times of ischemia employed.

Methods

Scientific papers published in PubMed for the period 2000–2020 were searched and reviewed.

Results

More than 30 natural anti-oxidants have been tested. The time of ischemia ranged from 15 to 90 min with 60 min used most frequently, followed by 45 min. No studies were found with time exceeding 90 min.

Conclusions

A significant number of research has been conducted on the use and protective effect of natural anti-oxidants in experimental animal models. Based on the published papers, 45–60 min seems to be the optimal duration of ischemia.

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Liver IRI is a multifactorial and complex process, involving many mechanisms, cells and mediators. Even though, most of these mechanisms have not been completely understood, several substances have been tested in experimental models in order to determine their protective or destructive role.

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Antioxidant therapy is a promising therapeutic pathway that can ameliorate the impact of liver ischemia-reperfusion injury.

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Non-pharmaceutical, natural extracts are increasingly gaining their place into the therapeutic options of physicians, in an attempt to avoid various adverse effects that the chemical drugs can cause.

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New unexplored research areas may include different strains of rats, more studies in larger mammals of comparable anatomy to humans, experiments on different liver diseases, publishing negative results regarding toxic doses of natural antioxidants, and testing different ischemia times.

Emerging roles of microRNAs in intestinal ischemia/reperfusion-induced injury: a review

Intestinal ischemia/reperfusion (II/R) injury is a serious pathological phenomenon in underlying hemorrhagic shock, trauma, strangulated intestinal obstruction, and acute mesenteric ischemia which associated with high morbidity and mortality. MicroRNAs (miRNAs, miRs) are endogenous non-coding RNAs that regulate post-transcriptionally target mRNA translation via degrading it and/or suppressing protein synthesis. This review discusses on the role of some miRNAs in underlying II/R injury. Some of these miRNAs can have protective action through agomiR or specific antagomiR, and others can have destructive effects in the basal level of II/R insult. Based on these literature reviews, II/R injury affects several miRNAs and their specific target genes. Some miRNAs upregulate under condition of II/R injury, and multiple miRNAs downregulate following II/R damage. Data of this review have been collected from the scientific articles published in databases such as Science Direct, Scopus, PubMed, Web of Science, and Scientific Information Database from 2000 to 2020. It is shown a correlation between changes in the expression of miRNAs and autophagy, inflammation, oxidative stress, apoptosis, and epithelial barrier function. Taken together, agomiR or antagomiR of some miRNAs can be considered as one new target for the research and development of innovative drugs to the prevention or treatment of II/R damage.

Role of Zinc Supplementation on Ischemia/Reperfusion Injury in Various Organs

Ischemia-reperfusion (I/R) injury is a serious condition which is associated with myocardial infarction, stroke, acute kidney injury, trauma, circulatory arrest, sickle cell disease, and sleep apnea and can lead to high morbidity and mortality. Salts of zinc (Zn) are commonly used by humans and have protective effects against gastric, renal, hepatic, muscle, myocardial, or neuronal ischemic injury. The present review evaluates molecular mechanisms underlying the protective effects of Zn supplement against I/R injury. Data of this review have been collected from the scientific articles published in databases such as Science Direct, Scopus, PubMed, and Scientific Information Database from 1991 to 2019. Zn supplementation increased the decreased parameters including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH), metallothionein (MT), protein sulfhydryl (P-SH), and nuclear factor-erythroid 2-related factor-2 (Nrf2) expression and decreased the increased elements such as endoplasmic reticulum (ER) stress, mitochondrial permeability transition pore (mPTP) opening, malondialdehyde (MDA), serum level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and microRNAs-(122 and 34a), apoptotic factors, and histopathological changes. Zn also increases phosphatidylinositol 3-kinase (PI3K)/Akt and glycogen synthase kinase-3β (GSK-3β) phosphorylation and preserves protein kinase C isoforms. It is suggested that Zn can be administered before elective surgeries for prevention of side effects of I/R injury.

Crocin attenuates cisplatin-induced hepatotoxicity via TLR4/NF-κBp50 signaling and BAMBI modulation of TGF-β activity: Involvement of miRNA-9 and miRNA-29

TLR4-induced mitigation of the BMP down-regulation and activin membrane bound inhibitor (BAMBI) and the consequent enhancement of the transforming growth factor-beta (TGF-β) profibrogenic signaling has not yet been studied in cisplatin (CIS)-induced hepatotoxicity. miRNA-9 and29 have been previously reported to modulate TLR4 signaling via either tempering the expression of nuclear factor kappa-B p50 (NF-κB p50) or downregulation of extracellular matrix genes respectively. Hence we aimed to investigate the involvement of TLR4-induced modulation of TGF-β receptor 1 (TGF-βR1) signaling as well as the implication of miRNA-9 and 29 in CIS-induced hepatotoxicity. Moreover, we examined the ability of the phytochemical; crocin (CROC); to interact with either TLR4 or TGF-βR1 through a molecular docking study and subsequently explore its capability to attenuate CIS-induced hepatotoxicity. CROC pretreatment ameliorated the CIS-induced enhancement of TLR4 and TGF-β signaling and enhanced the expression of BAMBI, miRNA-9 and 29. Accordingly, it may be assumed that the protective effect of CROC against CIS-induce hepatotoxicity is mediated via the crosstalk of TLR4/NF-κBp50 signaling and BAMBI modulation of TGF-β1 activity in addition to the up-regulation of miRNA-9 and 29. These findings came in alignment with our molecular docking results; emphasizing the molecular antagonistic activity of CROC in both TLR4 and TGF-βR1.

Inhibition of MiR-122 Decreases Cerebral Ischemia-reperfusion Injury by Upregulating DJ-1-Phosphatase and Tensin Homologue Deleted on Chromosome 10 (PTEN)/Phosphonosinol-3 Kinase (PI3K)/AKT

BACKGROUND Ischemia-reperfusion injury is caused by a blood reperfusion injury in ischemic brain tissue, and usually occurs in the treatment stage of ischemic disease, which can aggravate brain tissue injury. MiR-122 is closely related to ischemia-reperfusion injury in the myocardium, kidney, and liver; however, the role in cerebral ischemia-reperfusion injury has not been established. MATERIAL AND METHODS In this study, cerebral ischemia-reperfusion injury was established in a rat model, and the control group was a sham-operated group. After ischemia-reperfusion injury for 6, 12, and 24 hours, brain tissue specimens were collected and the expression of miR-122 and DJ-1 were determined using quantitative real-time polymerase chain reaction. Flow cytometry was used to determine the reactive oxygen species (ROS) content. The modified Neurological Severity Score (mNSS) scale was used to evaluate the sensory and motor function defects of the rats. The malondialdehyde (MDA), superoxide dismutase (SOD), and enzyme activity were determined. The rats in the cerebral ischemia-reperfusion injury model were divided into 2 groups (antagomir-NC group and antagomir miR-122 group). Brain neuron RN-c cells were divided into the following 4 groups: antagomir-NC, antagomir miR-122, pIRES2-blank, and pIRES2-DJ-1. Seventy-two hours after transfection, ischemia-reperfusion treatment was carried out and conventional cultured RN-c cells were used as the control group. Flow cytometry was used to detect apoptosis and western blot was used to detect the expression of DJ-1, PTEN, AKT, and p-AKT. RESULTS The expression of miR-122 increased significantly in the process of ischemia-reperfusion damage after cerebral infarction, while the expression of DJ-1 decreased significantly. Downregulation of miR-122 significantly increased the expression of DJ-1, enhanced the activity of the PTEN/PI3K/AKT pathway, reduced cell apoptosis, and alleviated cerebral ischemia-reperfusion injury. CONCLUSIONS Inhibition of miR-122 can decrease cerebral ischemia-reperfusion injury by upregulating DJ-1-PTEN/PI3K/AKT pathway.

The Protective Effect of Zinc Against Liver Ischaemia Reperfusion Injury in a Rat Model of Global Ischaemia

BACKGROUND

Ischaemia-reperfusion injury (IRI) is a major obstacle during liver transplantation and resection surgeries for cancer, with a need for effective and safe drugs to reduce IRI. Zinc preconditioning has been shown to protect against liver IRI in a partial (70%) ischaemia model. However, its efficacy against a clinically relevant Pringle manoeuvre that results in global liver ischaemia (100%) is unknown.

AIMS

The aim of this study was to test the efficacy of zinc preconditioning in a rat model of global liver ischaemia.

METHODS

Rats were preconditioned via subcutaneous injection of 10 mg/kg of ZnCl₂, 24 h and 4 h before ischaemia. Total liver ischaemia (100%) was induced by placing a clamp across the portal triad for 30 min. Liver injury was assessed by serum alanine transaminase (ALT) and aspartate transaminase (AST) levels in blood taken before ischaemia (baseline) and at 1, 2, 4, 24, 48, 72, 96 and 120 hours after ischaemia. Animals were culled after 7 days, and the harvested livers were histologically analysed.

RESULTS

On a two-way repeated-measures analysis of variance, there was a statistically significant (p = 0.025) difference in the mean ALT levels between saline- and ZnCl₂-treated groups. Specifically at 24 h after ischaemia, the ALT (341 ± 99 U/L) and AST (606 ± 78 U/L) in the zinc-treated group were significantly less than the ALT (2863 ± 828 U/L) and AST (3591 ± 948 U/L) values in the saline-treated group. Zinc significantly reduced neutrophil infiltration and necrosis compared with the saline control.

CONCLUSION

Zinc preconditioning reduces the overall hepatocellular damage from IRI. These results lay the foundation to assess the benefit of zinc preconditioning for clinical applications.

Crocin mitigates γ-rays-induced hepatic toxicity in rats

Crocin (C₄₄H₆₄O₂₄) is an isolated bioactive molecule of saffron extract. It has different pharmacological effects such as antioxidant and anti-inflammatory activities. In the present study, radioprotective property of crocin was investigated in the rat liver. Thirty-two rats were equally divided into four groups: (1) control (normal saline), (2) crocin (200 mg/kg), (3) γ-rays (6Gy), and (4) crocin plus γ-rays-treated groups. The liver histopathology, serum transaminases (ALT and AST), alkaline phosphatase (ALP), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and hepatic lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) have been assessed. The histopathological result of hepatic tissue in group 3 showed hydropic degeneration and this progressed to focal or spotty necrosis through the lobule. Moreover, some sinusoids are distended with blood or with leukocytic infiltrations. Other cases in group 3 showed periportal leukocytic infiltrations and necrosis extended out from the portal tract to involve hepatic lobules with fibrinous necrosis in portal vessels, while the examination of hepatic tissues of group 4 showed reduced deformities, irregular arrangement, congested hepatic vessels, and necrosis in hepatocytes. The results also showed significant decreased level of liver function activities, inflammatory markers, lipid peroxidation, and increased levels of liver antioxidants enzymes in group 4. Crocin showed moderate protective effect against γ-rays-induced liver toxicity. The antioxidant effect of crocin may be a major reason for its positive impact on liver parameters. Graphical abstract .

Hepatic ischemia-reperfusion injury in liver transplant setting: mechanisms and protective strategies

Hepatic ischemia-reperfusion injury is a major cause of liver transplant failure, and is of increasing significance due to increased use of expanded criteria livers for transplantation. This review summarizes the mechanisms and protective strategies for hepatic ischemia-reperfusion injury in the context of liver transplantation. Pharmacological therapies, the use of pre-and post-conditioning and machine perfusion are discussed as protective strategies. The use of machine perfusion offers significant potential in the reconditioning of liver grafts and the prevention of hepatic ischemia-reperfusion injury, and is an exciting and active area of research, which needs more study clinically.

Vildagliptin Attenuates Hepatic Ischemia/Reperfusion Injury via the TLR4/NF-κB Signaling Pathway

The Toll-like receptor-4 (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway is vital in the pathogenesis of hepatic ischemia/reperfusion (HIR) injury. Dipeptidyl peptidase-4 (DPP4) inhibitors exert protective effects on IR injury of the kidney, heart, and lung; however, their effect on the liver is still unknown. Thus, the purpose of this study was to examine whether pretreatment with vildagliptin (Vilda), a DPP4 inhibitor, produces hepatic protection against IR injury and to investigate its influence on TLR4/NF-κB signaling in a rat model. Thirty male Wistar rats were divided into 3 groups: the sham group: subjected to a sham operation and received normal saline; the HIR group: subjected to HIR and received normal saline; and the Vilda + HIR group: subjected to HIR with pretreatment of 10 mg/kg/day Vilda for 10 days intraperitoneally. Hepatic ischemia lasted for 45 minutes followed by 3-hour reperfusion; then blood and liver samples were collected for biochemical and histopathological examination. The HIR group produced a significant increase in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic malondialdehyde (MDA), nitric oxide (NO), and tumor necrosis factor alpha (TNF-α) levels and a significant reduction in the hepatic catalase level in comparison to the sham group. Moreover, a significant upregulation of gene and protein expressions of TLR4, NF-κB, and high-mobility group box-1 (HMGB1) along with caspase-3 protein expression was observed in the HIR group when compared with the sham group. Histopathological examination of the liver from the HIR group showed necrosis, sinusoidal congestion, hemorrhage, and hepatocyte degeneration. Administration of Vilda ameliorated the biochemical and histopathological changes caused by HIR. Vildagliptin showed for the first time a hepatoprotective effect in HIR injury through downregulation of TLR4/NF-κB/HMGB1 and caspase-3 hepatic expressions.

Novel Targets for Treating Ischemia-Reperfusion Injury in the Liver

Liver ischemia-reperfusion injury (IRI) is a major complication of hemorrhagic shock, liver transplantation, and other liver surgeries. It is one of the leading causes for post-surgery hepatic dysfunction, always leading to morbidity and mortality. Several strategies, such as low-temperature reperfusion and ischemic preconditioning, are useful for ameliorating liver IRI in animal models. However, these methods are difficult to perform in clinical surgeries. It has been reported that the activation of peroxisome proliferator activated receptor gamma (PPARγ) protects the liver against IRI, but with unidentified direct target gene(s) and unclear mechanism(s). Recently, FAM3A, a direct target gene of PPARγ, had been shown to mediate PPARγ’s protective effects in liver IRI. Moreover, noncoding RNAs, including LncRNAs and miRNAs, had also been reported to play important roles in the process of hepatic IRI. This review briefly discussed the roles and mechanisms of several classes of important molecules, including PPARγ, FAM3A, miRNAs, and LncRNAs, in liver IRI. In particular, oral administration of PPARγ agonists before liver surgery or liver transplantation to activate hepatic FAM3A pathways holds great promise for attenuating human liver IRI.

A comprehensive review on regulatory effects of crocin on ischemia/reperfusion injury in multiple organs

Ischemia-reperfusion (I/R) injury affects o₂-dependent organs including liver, kidneys, heart, brain, and intestine. I/R injury is described as the cellular injury in an organ caused by ischemia and then further aggravated during the reperfusion due to intracellular alterations. It is a process that happens in clinical settings such as organ transplantation, reperfusion after thrombolytic therapy, and coronary angioplasty. Crocus sativus L. known as saffron used in folk medicine for its beneficial effects. It contains multiple bioactive compounds including the crocin, crocetin, picrocrocin, and safranal. Crocin, a water-soluble carotenoid has antitumor, radical scavenging, anti hyperlipidemia and memory improving effects. Moreover, crocin has antioxidant, and protective effects on I/R models in rats at various organs such as heart, brain, kidney, stomach, liver, and kidney as described in detail in this review.