Prostaglandin E-major urinary metabolites as a new biomarker for acute mesenteric ischemia.

BACKGROUND: Acute mesenteric ischemia (AMI) is an emergent vascular disease caused by cessation of the blood supply to the small intestine. Despite advances in the diagnosis, intervention, and surgical procedures, AMI remains a life-threatening condition. Prostaglandin E2 major urinary metabolite (PGE-MUM), the urinary metabolite of prostaglandin E2, is known to be stable in urine and has been suggested to be a valuable biomarker for intestinal mucosal inflammation, such as ulcerative colitis. We therefore investigated whether or not PGE-MUM levels reflect the degree of ischemia in an intestinal ischemia-reperfusion model. METHODS: Male rats were used to establish a superior mesenteric artery occlusion (SMAO) group, in which the superior mesenteric artery was clamped, and a sham group. The clamping times in the SMAO group were either 30 minutes or 60 minutes, and reperfusion times were either 3 hours or 6 hours, after which PGE-MUM values were measured. RESULTS: The histological injury score of the SMAO (30-minute ischemia and 6-hour reperfusion group, 1.8 ± 0.4; 60-minute ischemia and 6-hour reperfusion group, 4.7 ± 0.5) and were significantly greater than that of the sham group (0.4 ± 0.7, p < 0.05). The PGE-MUM levels in the SMAO group (30-minutes ischemia and 6-hour reperfusion group, 483 ± 256; 60-minutes ischemia and 6-hour reperfusion group, 889 ± 402 ng/mL) were significantly higher than in the sham group (30-minute and 6-hour observation group, 51 ± 20; 60-minute and 6-hour observation group, 73 ± 32 ng/mL; p < 0.05). Furthermore, the PGE-MUM value was corrected by the concentration of urinary creatinine (Cr). The PGE-MUM/urinary Cr levels in the SMAO group were also significantly higher than in the sham group ( p < 0.05). CONCLUSION: We found that intestinal ischemia-reperfusion increased urinary PGE-MUM levels depending on the ischemic time. This suggests the potential utility of PGE-MUM as a noninvasive marker of intestinal ischemia.

Postreperfusion Syndrome in Patients Receiving Vasoactive Drugs During Liver Graft Reperfusion.

OBJECTIVES: The most widely used definition of postreperfusion syndrome in liver transplant is a 30% decrease in mean arterial pressure during the first 5 minutes after vascular unclamping. With these criteria, increased postoperative morbidity has been reported. Vasoactivedrugs couldpreventthis syndrome.Themain objective of our study was to determine the incidence and complications associated with postreperfusion syndrome inpatientswho receivedvasoactive support. MATERIALS AND METHODS: We studied 246 patients who received norepinephrine infusions to maintain mean arterial pressure ≥60 mm Hg and who were monitored with a Swan-Ganz catheter. Patients received a bolus of adrenaline after vascular unclamping in cases of insufficient response to norepinephrine. RESULTS: Among the study patients, 57 (23.17%) developed postreperfusion syndrome. Patients who developed postreperfusion syndrome did not present with morepostoperative complications interms ofrenal dysfunction (P = .69), repeat surgery (P = .15), graft rejection (P = .69), transplant replacement surgery (P = .76), hospital stay (P = .70), or survival (P = .17) compared with patients without postreperfusion syndrome. CONCLUSIONS: In patients who underwent orthotopic liver transplant, in whom vasoactive drugs were administered, a diagnosis of self-limited postreperfusion syndrome during the first 5 minutes after unclamping may not be associated with postoperative complications. The administration of vasoconstrictors may have a preventive effect on the postoperative complications associated with postreperfusion syndrome or they may mask the real incidence of postreperfusion syndrome. A broader definition of postreperfusion syndrome should be accepted.

Inter-patient heterogeneity in the hepatic ischemia-reperfusion injury transcriptome: Implications for research and diagnostics.

Cellular responses induced by surgical procedure or ischemia-reperfusion injury (IRI) may severely alter transcriptome profiles and complicate molecular diagnostics. To investigate this effect, we characterized such pre-analytical effects in 143 non-malignant liver samples obtained from 30 patients at different time points of ischemia during surgery from two individual cohorts treated either with the Pringle manoeuvre or total vascular exclusion. Transcriptomics profiles were analyzed by Affymetrix microarrays and expression of selected mRNAs was validated by RT-PCR. We found 179 mutually deregulated genes which point to elevated cytokine signaling with NFκB as a dominant pathway in ischemia responses. In contrast to ischemia, reperfusion induced pro-apoptotic and pro-inflammatory cascades involving TNF, NFκB and MAPK pathways. FOS and JUN were down-regulated in steatosis compared to their up-regulation in normal livers. Surprisingly, molecular signatures of underlying primary and secondary cancers were present in non-tumor tissue. The reported inter-patient variability might reflect differences in individual stress responses and impact of underlying disease conditions. Furthermore, we provide a set of 230 pre-analytically highly robust genes identified from histologically normal livers (<2% covariation across both cohorts) that might serve as reference genes and could be particularly suited for future diagnostic applications.

Physiologically-Based Pharmacokinetic Modeling of Blood Clearance of Liver Fluorescent Markers for the Assessment of the Degree of Hepatic Ischemia-Reperfusion Injury.

During liver transplantation, ischemia-reperfusion injury (IRI) is inevitable and decreases the overall success of the surgery. While guidelines exist, there is no reliable way to quantitatively assess the degree of IRI present in the liver. Our recent study has shown a correlation between the bile-to-plasma ratio of FDA-approved sodium fluorescein (SF) and the degree of hepatic IRI, presumably due to IRI-induced decrease in the activity of the hepatic multidrug resistance-associated protein 2 (MRP2); however, the contribution of SF blood clearance via the bile is still convoluted with other factors, such as renal clearance. In this work, we sought to computationally model SF blood clearance via the bile. First, we converted extant SF fluorescence data from rat whole blood, plasma, and bile to concentrations using calibration curves. Next, based on these SF concentration data, we generated a "liver-centric", physiologically-based pharmacokinetic (PBPK) model of SF liver uptake and clearance via the bile. Model simulations show that SF bile concentration is highly sensitive to change in the activity of hepatic MPR2. These simulations suggest that SF bile clearance along with the PBPK model can be used to quantify the effect of IRI on the activity of MRP2.Clinical Relevance- This study establishes the theory necessary to generate a model for predicting the degree of IRI during liver transplantation.

Point-of-care salivary oxidative and renal functional markers to assess kidney function in reperfusion-induced acute kidney injury in male rats.

OBJECTIVES: Saliva is one of the most promising body fluids in the research of new biomarker for various diseases diagnosis. However, serial sampling in this condition is very dangerous and pose iatrogenic anemia with blood loss. This study was done to evaluate the cost-effectiveness of point-of-care salivary tests and identify the validity of salivary markers. METHODS: Rats were randomly assigned to four experimental groups: (1) control (2) IR-3 h (3) IR-6 h (4) IR-24 h. Both renal pedicles were occluded for 55 min and then were declamped to allow reperfusion for 3, 6 and 24 h in IR groups. After reperfusion, all rats received pilocarpine 1 mg/kg to collect saliva. Plasma samples were also collected. Renal parameters including Cr, uric acid, and urea, malondialdehyde (MDA) levels, Bax/Bcl2 ratio, nitrite/nitrate ratio, corticosterone levels and oxidant/antioxidant ratio were measured in both plasma and salivary samples. RESULTS: There were significant increased level of renal function parameters, MDA levels, Bax/Bcl2 ratio, nitrite/nitrate ratio and corticosterone in both saliva and plasma. The comparison of above parameters in both saliva and plasma showed significant correlation. CONCLUSIONS: This study demonstrated that concentrations of indices specifically renal functional parameters increase in saliva in the IR-induced kidney injury in male rats and result indicate the potential of saliva as a tool to monitoring AKI. Measurement of salivary parameters may can become reliable diagnostic tests for patients with AKI.

Postreperfusion Biopsy as a Predictor of Biliary Complication After Deceased Donor Liver Transplantation. A Retrospective Cohort Study.

BACKGROUND: Ischemia reperfusion injury (IRI) on postreperfusion biopsies is associated with worse outcomes after liver transplantation, although the influence on biliary complications (BC) remains poorly studied. Therefore, the primary aim of our study was to assess the influence of IRI on the incidence of BC. A secondary aim was to assess the influence of steatosis on biliary complications and determine factors that predictor BC. METHODS: We report a retrospective cohort study including patients with liver transplantation and postreperfusion injury. Biopsies were classified as relevant and nonrelevant ischemia reperfusion injury for assessment of BC. BC included anastomotic stricture, ischemic cholangiopathy, leaks, and bilomas. Independent predictive factors of biliary complications were assessed using univariate and multivariate analyses. RESULTS: 302 patients were included, and 125 patients fulfilled the criteria for relevant IRI (41.4%). Worse IRI was not associated with biliary complications (42.5% vs 40.1%; P = .68), nor was liver graft steatosis associated with BC (40.5% vs 41.5%, P = .95). The median time until biliary complications did not differ between the 2 groups (2 months; interquartile range = 1-15 vs 3 months; interquartile range = 1-12.5; P = .18). Hepatic artery thrombosis (odds ratio [OR] = 3.4; 95% confidence interval [CI], 1.4-8.2; P = .004), older donor age (OR = 2.1; 95% CI, 1.1-4.1; P = .024), and prolonged cold ischemia time (OR = 1.9; 95% CI, 1.1-3.2) were independent factors of biliary complications. CONCLUSION: Severe IRI on the postreperfusion injury does not predict development of biliary complications.

Reappraisal of ischemia-reperfusion injury in a short duration laparoscopic surgery, a pilot study.

BACKGROUND: Serum biochemical changes during laparoscopic surgery and positive pressure pneumoperitoneum (PP) may reflect mild oxidative stress due to the ischemia-reperfusion (I/R) mechanism. However, there is still a controversy regarding the exact mechanism of PP in creating oxidative stress and whether the induction of PP causes I/R effects at all. To elucidate this debated issue, we studied, for the first time, the changes of I/R parameters in the serum, in a pilot study, during laparoscopic cholecystectomy using a reliable, independent exogenous oxidative biomarker, together with common intrinsic biomarkers of oxidative stress. PATIENTS AND METHODS: Our study included 20 patients scheduled for elective laparoscopic cholecystectomy. We evaluated the levels of the extrinsic and endogenous markers for oxidative stress during awareness, under anesthesia, the end of surgery (abdominal CO2 evacuation), and 2 h afterward. RESULTS: After an initial increase in oxidative stress following anesthesia, we did not notice any further significant rise in the levels of the synthetic exogenous and the endogenous biomarkers at the end of the surgery and 2 h later on. However, a positive correlation was noted between the levels of both the intrinsic and extrinsic markers. CONCLUSIONS: In our study, the capability of the extrinsic biomarker to detect mild oxidative stress was not validated. Our study stresses the heterogeneous nature of the oxidative reactions and the diversity of the endogenous and exogenous biomarkers while detecting various biochemical patterns under mild oxidative stress, during the short period of laparoscopic surgery.

Methyl eugenol attenuates liver ischemia reperfusion injury via activating PI3K/Akt signaling.

BACKGROUND: Liver ischemia reperfusion injury (LIRI) often occurs during liver transplantation, resection, and various circulatory shock procedures, leading to severe metabolic disorders, inflammatory immune responses, oxidative stress injury, and cell apoptosis. Methyl eugenol (ME) is structurally similar to eugenol and has anti-inflammatory and apoptotic pharmacological effects. However, whether ME protects the liver from LIRI damage requires further investigation. METHODS: We established a partially warm LIRI model by subjecting C57BL/6J mice to 60 min of ischemia, followed by reperfusion for 6 h. We also established a hypoxia-reoxygenation injury (H/R) cell model by subjecting AML12 (a mouse liver cell line) cells to 24 h hypoxia, followed by 18 h normoxia. The extent of liver injury was assessed by serum transaminase concentrations, hematoxylin and eosin staining, quantitative real-time PCR, myeloperoxidase activity, and TUNEL analysis. Apoptosis was detected using flow cytometry. The protein levels of p-PI3K, PI3K, p-Akt, Akt, p-Bad, Bad, Bcl-2, Bax, and cleaved caspase-3 were detected by western blotting. LY294002, an inhibitor of PI3K/Akt signaling, was used to elucidate the relationship between ME and PI3K/Akt signaling. RESULTS: ME successfully alleviated LIRI-induced liver injury, inflammatory response, and apoptosis induced, as well as liver cell injury induced by hypoxia reoxygenation. ME is known to activate the PI3K/Akt signaling pathway in hepatocyte injury in vivo and in vitro, and when this signaling pathway is inhibited, the protective effect of ME is abrogated. CONCLUSIONS: The use of ME is a potential therapeutic approach for regulating LIRI by activating PI3K/Akt signaling.

Recipient and surgical factors trigger severe primary graft dysfunction after heart transplant.

BACKGROUND: Primary graft dysfunction (PGD) is a major cause of early mortality following heart transplant (HT). The International Society for Heart and Lung Transplantation (ISHLT) subdivides PGD into 3 grades of increasing severity. Most studies have assessed risk factors for PGD without distinguishing between PGD severity grade. We sought to identify recipient, donor and surgical risk factors specifically associated with mild/moderate or severe PGD. METHODS: We identified 734 heart transplant recipients at our institution transplanted between January 1, 2012 and December 31, 2018. PGD was defined according to modified ISHLT criteria. Recipient, donor and surgical variables were analyzed by multinomial logistic regression with mild/moderate or severe PGD as the response. Variables significant in single variable modeling were subject to multivariable analysis via penalized logistic regression. RESULTS: PGD occurred in 24% of the cohort (n = 178) of whom 6% (n = 44) had severe PGD. One-year survival was reduced in recipients with severe PGD but not in those with mild or moderate PGD. Multivariable analysis identified 3 recipient factors: prior cardiac surgery, recipient treatment with ACEI/ARB/ARNI plus MRA, recipient treatment with amiodarone plus beta-blocker, and 3 surgical factors: longer ischemic time, more red blood cell transfusions, and more platelet transfusions, that were associated with severe PGD. We developed a clinical risk score, ABCE, which provided acceptable discrimination and calibration for severe PGD. CONCLUSIONS: Risk factors for mild/moderate PGD were largely distinct from those for severe PGD, suggesting a differing pathophysiology involving several biological pathways. Further research into mechanisms underlying the development of PGD is urgently needed.

Molecular ultrasound imaging of neutrophil membrane-derived biomimetic microbubbles for quantitative evaluation of hepatic ischemia-reperfusion injury.

Rationale: Early diagnosis of hepatic ischemia-reperfusion injury (HIRI), the major cause of early allograft dysfunction or primary non-function, is critical in orthotopic liver transplantation. However, liver biopsy is still the primary method for HIRI evaluation in clinical practice despite its numerous complications and shortcomings such as hemorrhage and inaccuracy. Herein, we aimed to develop a non-invasive, highly accurate, and specific method for detecting HIRI. Methods: We developed a top-down and bottom-up strategy to fabricate neutrophil biomimetic microbubbles (MBneu). Neutrophil membrane was mixed with liposomes at a defined mass ratio by sonication. The air in the vial was exchanged with perfluoropropane, and then the solution was mechanically vibrated to form MBneu. Results: MBneu retained the neutrophil proteins, preferentially targeted inflamed hepatic tissue in a rat model of HIRI, and demonstrated physicochemical properties typical of liposome-based MBs because of its artificial phospholipid content. With MBneu we can quantitively evaluate the severity of HIRI, which is helpful for early diagnosis and the prediction of outcome. In addition, MBneu was shown to be safe and showed no immunogenicity. Conclusion: We demonstrated molecular ultrasound imaging of HIRI with MBneu. This new synthesis strategy may be applied to different clinical scenarios using other cell types in the future.

Analysis of blood parameters and molecular endometrial markers during early reperfusion in two ovine models of uterus transplantation.

The dissection of the veins is the trickiest step of Uterine transplantation (UTx). Performing the anastomosis of a single uterine vein could bring a therapeutic benefit and simplification of surgery and serve for managing unilateral venous thromboses. The objectives of this project were to evaluate the expression of early markers of ischemia-reperfusion and to compare findings following one or two vein anastomoses. Orthotopic uterine auto-transplantations were performed on an ovine model with anastomosis of either two (group 1) or one utero-ovarian veins (group 2). Blood gases, histology and ischemia- reperfusion markers transcripts (PTGS2, IL6, IL8, SOD2, C3, BAX/BCL2 and TLR4) were analyzed as well as PTGS2 protein expression using Western Blot and fluorescence immunolocalization on endometrial biopsies after 3h of reperfusion. Ten ewes were included in the experimentation, 4 were in group1, 3 in group 2, the others being sham operated controls. No significant differences were observed between the two phenotypes. Based on these results, the anastomosis of one single uterine vein appears to be an approach consistent with short-term graft survival. Further experiments will be needed to confirm the reliability of this approach, especially the long-term follow-up of the uterine graft including its ability to support gestation to term.

Effect of ischemia-reperfusion on outcomes after open mesenteric bypass for chronic mesenteric ischemia.

OBJECTIVE: Significant physiologic perturbations can occur in patients with chronic mesenteric ischemia (CMI) undergoing open mesenteric bypass (OMB). These events have frequently been attributed to ischemia-reperfusion events and have been directly implicated in the occurrence of multiple organ dysfunction (MOD). Scoring systems (MOD score [MODS] and sequential organ failure assessment [SOFA]) have been derived within the critical care field to provide a composite metric for these pathophysiologic changes. The purpose of the present study was to describe the early pathophysiologic changes that occur after OMB for CMI and determine whether these are predictive of the outcomes. METHODS: Patients with CMI who had undergone elective OMB from 2002 to 2018 at a single institution were reviewed. Changes in the hemodynamic, pulmonary, hepatic, renal, and hematologic parameters in the first 96 hours postoperatively were analyzed. The MODSs and SOFA scores were calculated. Cox regression was used to determine the association of the MODSs and SOFA scores with the outcomes. RESULTS: The use of OMB was analyzed for 72 patients (age, 66 ± 11 years; 68% women; body mass index, 23.8 ± 6 kg/m2; 48 ± 34-lb weight loss in 59%). Previous mesenteric stent placement or bypass had been performed in 39% [stenting in 21; bypass in 8; (one patient had both)]. An antegrade configuration (93%) was most common (retrograde configuration, 7%), with revascularization of the superior mesenteric artery/celiac vessels in 85% (superior mesenteric artery only in 15%). Postoperative pathophysiologic and metabolic changes were common, and the mean MODSs and SOFA scores were 3.6 ± 2.4 (range, 1-10) and 4.0 ± 2.7 (range, 1-13), respectively. The median length of stay was 14 days (interquartile range, 9-21). The 30-day mortality was 4% (n = 3) and in-hospital morbidity was 53% (n = 38; gastrointestinal, 25%; infectious, 22%; cardiac, 18%; pulmonary, 18%; renal, 11%). The clinical follow-up period was 16 ± 20 months. The MODSs and SOFA scores correlated linearly with overall mortality (MODS: odds ratio [OR], 1.4; 95% confidence interval [CI], 1.2-1.7; P < .01; SOFA score: OR, 1.4; 95% CI, 1.2-1.7; P < .01 per unit), with a score of ≥5 the inflection point most predictive of mortality (MODS: OR, 3.9; 95% CI, 1.6-9.9; P ≤ .01; SOFA score: OR, 2.8; 95% CI, 1.2-6.6; P = .02). The 1- and 3-year primary bypass patency and freedom from reintervention was 91% ± 5% and 83% ± 7%, respectively, with no association with the MODSs or SOFA scores. The 1- and 3-year survival was 86% ± 4% and 71% ± 6% with significantly worse outcomes for patients with higher MODSs and/or SOFA scores. CONCLUSIONS: Most CMI patients undergoing OMB will experience significant metabolic derangements resulting from sequelae of the ischemia-reperfusion phenomenon postoperatively. These can be objectively assessed in the early postoperative period using simply applied scoring systems to reliably predict the early and long-term outcomes. A derivation of the MODS and/or SOFA score after OMB for CMI can identify the most vulnerable patients at the greatest risk of mortality.

Genes Induced by Panax Notoginseng in a Rodent Model of Ischemia-Reperfusion Injury.

Stroke is a cerebrovascular disease that results in decreased blood flow. Although Panax notoginseng (PN), a Chinese herbal medicine, has been proven to promote stroke recovery, its molecular mechanism remains unclear. In this study, middle cerebral artery occlusion (MCAO) was induced in rats with thrombi generated by thread and subsequently treated with PN. After that, staining with 2,3,5-triphenyltetrazolium chloride was employed to evaluate the infarcted area, and electron microscopy was used to assess ultrastructural changes of the neurovascular unit. RNA-Seq was performed to determine the differential expressed genes (DEGs) which were then verified by qPCR. In total, 817 DEGs were identified to be related to the therapeutic effect of PN on stroke recovery. Further analysis by Gene Oncology analysis and Kyoto Encyclopedia of Genes and Genomes revealed that most of these genes were involved in the biological function of nerves and blood vessels through the regulation of neuroactive live receptor interactions of PI3K-Akt, Rap1, cAMP, and cGMP-PKG signaling, which included in the 18 pathways identified in our research, of which, 9 were reported firstly that related to PN's neuroprotective effect. This research sheds light on the potential molecular mechanisms underlying the effects of PN on stroke recovery.

Local complement activation is associated with primary graft dysfunction after lung transplantation.

BACKGROUNDThe complement system plays a key role in host defense but is activated by ischemia/reperfusion injury (IRI). Primary graft dysfunction (PGD) is a form of acute lung injury occurring predominantly due to IRI, which worsens survival after lung transplantation (LTx). Local complement activation is associated with acute lung injury, but whether it is more reflective of allograft injury compared with systemic activation remains unclear. We proposed that local complement activation would help identify those who develop PGD after LTx. We also aimed to identify which complement activation pathways are associated with PGD.METHODSWe performed a multicenter cohort study at the University of Pennsylvania and Washington University School of Medicine. Bronchoalveolar lavage (BAL) and plasma specimens were obtained from recipients within 24 hours after LTx. PGD was scored based on the consensus definition. Complement activation products and components of each arm of the complement cascade were measured using ELISA.RESULTSIn both cohorts, sC4d and sC5b-9 levels were increased in BAL of subjects with PGD compared with those without PGD. Subjects with PGD also had higher C1q, C2, C4, and C4b, compared with subjects without PGD, suggesting classical and lectin pathway involvement. Ba levels were higher in subjects with PGD, suggesting alternative pathway activation. Among lectin pathway-specific components, MBL and FCN-3 had a moderate-to-strong correlation with the terminal complement complex in the BAL but not in the plasma.CONCLUSIONComplement activation fragments are detected in the BAL within 24 hours after LTx. Components of all 3 pathways are locally increased in subjects with PGD. Our findings create a precedent for investigating complement-targeted therapeutics to mitigate PGD.FUNDINGThis research was supported by the NIH, American Lung Association, Children's Discovery Institute, Robert Wood Johnson Foundation, Cystic Fibrosis Foundation, Barnes-Jewish Hospital Foundation, Danish Heart Foundation, Danish Research Foundation of Independent Research, Svend Andersen Research Foundation, and Novo Nordisk Research Foundation.

MicroRNAs and long non-coding RNAs in liver surgery: Diagnostic and therapeutic merits.

BACKGROUND: Hepatectomy and liver transplantation (LT) are the two most commonly performed surgical procedures for various hepatic lesions. microRNA (miRNA) and long non-coding RNA (lncRNA) have been gradually unveiled their roles as either biomarkers for early diagnosis or potentially therapeutic tools to manipulate gene expression in many disease entities. This review aimed to discuss the effects of miRNA or lncRNA in the hepatectomy and LT fields. DATA SOURCES: We did a literature search from 1990 through January 2018 to summarize the currently available evidence with respect to the effects of miRNA and lncRNA in liver regeneration after partial hepatectomy, as well as their involvement in several key issues related to LT, including ischemia-reperfusion injury, allograft rejection, tolerance, recurrence of original hepatic malignancies, etc. RESULTS: Certain miRNAs and lncRNAs are actively involved in the regulation of various aspects of liver resection and transplantation. During the process of liver regeneration after hepatectomy, the expression of miRNAs and lncRNAs shows dynamic changes. CONCLUSIONS: It is now clear that miRNAs and lncRNAs orchestrate in various aspects of the pathophysiological process of LT and hepatectomy. Better understanding of the underlying mechanism and future clinical trials may strengthen their positions as either biomarkers or potential therapeutic targets in the management of complications after liver surgery.

cMet agonistic antibody attenuates apoptosis in ischaemia-reperfusion-induced kidney injury.

Acute kidney injury (AKI) is a very common complication with high morbidity and mortality rates and no fundamental treatment. In this study, we investigated whether the hepatocyte growth factor (HGF)/cMet pathway is associated with the development of AKI and how the administration of a cMet agonistic antibody (Ab) affects an AKI model. In the analysis using human blood samples, cMet and HGF levels were found to be significantly increased in the AKI group, regardless of underlying renal function. The administration of a cMet agonistic Ab improved the functional and histological changes after bilateral ischaemia-reperfusion injury. TUNEL-positive cells and Bax/Bcl-2 ratio were also reduced by cMet agonistic Ab treatment. In addition, cMet agonistic Ab treatment significantly increased the levels of PI3K, Akt and mTOR. Furthermore, after 24 hours of hypoxia induction in human proximal tubular epithelial cells, treatment with the cMet agonistic Ab also showed dose-dependent antiapoptotic effects similar to those of the recombinant HGF treatment. Even when the HGF axis was blocked with a HGF-blocking Ab, the cMet agonistic Ab showed an independent dose-dependent antiapoptotic effect. In conclusion, cMet expression is associated with the occurrence of AKI. cMet agonistic Ab treatment attenuates the severity of AKI through the PI3K/Akt/mTOR pathway and improves apoptosis. cMet agonistic Ab may have important significance for the treatment of AKI.

Effect of unilateral testicular torsion on contralateral testis in a rat model.

OBJECTIVE: The aim of this study was to investigate the function of the contralateral testis after unilateral testicular torsion (UTT) and its possible mechanism. METHODS: 56 rats were randomly divided into four groups: Group A: Sham operation, Group B: Testicular torsion (TT)+normal saline (NS), Group C: Testicular torsion (TT)+cyclosporine, Group D: Testicular torsion (TT)+NG-Monomethyl-L-arginine (L-NMMA). The right testes were removed 1 week and 8 weeks after surgery, respectively. Biochemistry and histopathologic evaluations were used to evaluate the germ cell damage. RESULTS: Compared with Group A, the levels of malondialchehyche (MDA) and nitric oxide (NO)/nitricoxide synthase (NOS) were increased remarkably in Group B. Significant differences were shown between histopathological damages and density and motility of sperm in two groups. Compared with Group B, the levels of MDA and NO/NOS in Group D decreased significantly while mean seminiferous tubule diameter (MSTD) and mean testicular biopsy scoring (MTBS) maintained in a better condition. The levels of major histocompatibility complex (MHC) peptide-tetramer complex in Group C and Group D decreased significantly than Group B, while sperm density and motility were significantly higher than Group B. It was also known that the histopathological damages in Group C and Group D were less than those in Group B in the 8 weeks after operation. CONCLUSION: UTT can cause impairment of contralateral testicular function and decrease of spermatogenic function. The mechanism may be related to ischemia-reperfusion (IR) in early stage and autoimmune response in late stage.

Huoxue-Tongluo-Lishui-Decoction is visual-protective against retinal ischemia-reperfusion injury.

Retinal ischemia reperfusion injury (IRI) is a leading cause of visual impairment or blindness, and an effective way to prevent the visual loss needs to be developed. Although decades of clinical application of Huoxue-Tongluo-Lishui-Decoction (HTLD) has demonstrated its reliable clinical efficacy against retinal IRI, no convincing randomized controlled trials were conducted in humans or animals, and the associated mechanism still needs to be explored. To confirm the protective effect of HTLD against retinal IRI and to explore its underlying mechanisms, a standard retinal IRI animal model, randomized controlled trials, objective evaluation and examination methods were adopted in this study. Flash visual evoked potentials (F-VEP) was performed 8 weeks post-reperfusion. The results showed that the medium dose of HTLD had better treatment effects than low dose of HTLD. High dose of HTLD did not further improve visual function relative to medium dose of HTLD, but had poor performance in the latency of P2 wave. The angio-optical coherence tomography (angio-OCT) examination showed that retinal nerve fiber layer (RNFL) became edematous in the early stage, then the edema subsided, and RNFL became thinning in the late stage. HTLD reduced the swelling of RNFL in the early stage and prevented the thinning of RNFL in the late stage. Similar to F-VEP, medium dose of HTLD has the best neural-protective effects against retinal IRI. In mechanisms, HTLD treatment not only enhanced autophagy at 6 h after reperfusion, but extended the enhancing effect until at least 24 h. HTLD treatment significantly reduced the cleaved Caspase-3, cleaved PARP and Caspase-3 activity at 48 h after reperfusion. HTLD inhibited neuro-toxic cytokines expression in retinal IRI by modulating Akt/NF-kB signaling. HTLD treatment enhanced the expressions of L-glutamate/L-aspartate transporter (GLAST) and glutamine synthetase (GS), and lower the concentration of free glutamate in retina after reperfusion. The phosphorylation of iNOS increased significantly in retinal IRI at 6 h, and HTLD treatment suppressed the phosphorylation of Inducible nitric oxide synthetase (iNOS). In conclusion, HTLD is visual-protective against retinal IRI, and the regulation of autophagy, apoptosis and neuro-toxic mediators may be the underlying mechanisms. These findings may provide new ideas for the clinical treatment of retinal IRI related diseases.

The Role of microRNA in Hepatic Ischemia/Reperfusion Injury.

INTRODUCTION: Ischemia-Reperfusion (I/R) injuries are caused by complex interrelated mechanisms and pathways. Regarding the liver, I/R injuries and their clinical manifestations are crucial for the surgical outcome. Despite its importance, there is no broadly accepted therapy either for the prevention or for the management of I/R injury. I/R injury of the liver can occur either during hepatic surgery (warm) or during the transplantation procedure (cold). MicroRNAs play a pivotal role in the mechanism of I/R injury, as they regulate the expression of the cellular participants and humoral factors associated with I/R injury. OBJECTIVE: In this review, we highlight the microRNAs that are involved in the I/R injury of the liver, and the molecular pathways that they regulate. In addition, we discuss the potential role of circulating microRNAs as biomarkers and their role as pharmacological targets in the prevention, diagnosis and treatment of I/R injuries. METHOD: We conducted a comprehensive review of the PubMed bibliographic database regarding microRNAs and I/R injuries of the liver. RESULTS: In diagnostics, microRNA panels could replace invasive diagnostic procedures, relieving patients of the associated complications. In therapeutics, microRNAs, agomirs, antagomirs and other drugs can be used to shift the balance between proapoptotic and survival pathways, to alleviate the liver damage caused by I/R. In transplantation procedures, microRNA profiling could decrease the incidence of early graft dysfunction, especially regarding marginal grafts. CONCLUSION: Although microRNAs seem a very promising clinical tool in the management of I/R injuries, further research is required, until microRNAs become a novel tool in the diagnosis and monitoring of an I/R injury of the liver.

Protective effects of autophagy inhibitor 3-methyladenine on ischemia-reperfusion-induced retinal injury.

OBJECTIVE: To investigate the protective effects of autophagy inhibitor 3-methyladenine (3-MA) in a rat model of ischemic-reperfusion injury (IRI). METHODS: Forty Sprague-Dawley male rats (weight 220-250 g) were randomly divided into four groups: a control group (NC, n = 10), a Sham surgery group (n = 10), an IRI group (n = 10), and a 3-MA-treated IRI group [10 µL 3-MA (10 mmol/L) was injected in vitreous after the injury, n = 10]. The retinal IRI was induced by elevating the intraocular pressure to 110 mmHg for 60 min. Hematoxylin and eosin (HE) staining was used to calculate the number of retinal ganglion cells (RGCs). The level of microtubule-associated protein 1A/1B light chain 3 (LC3), Beclin-1, and Caspase-3 in the retina was detected using the immunofluorescence staining method. The LC3, Beclin-1, B-cell lymphoma/leukemia-2 (Bcl-2), and Caspase-3 protein levels were examined by Western blotting. RESULTS: The number of RGCs in IRI group was significantly lower than that in NC group (P < 0.05), demonstrated by HE staining. Western blotting results indicated that the protein expression of LC3 and Beclin-1 in the IRI group was significantly elevated compared with those in the NC group (P < 0.05). However, with 3-MA treatment, the number of RCGs in 3-MA-treated IRI group was elevated and protein levels of LC3, Beclin-1 were down-regulated, compared with those in the IRI group (P < 0.05). Further immunohistochemistry staining and Western blot showed that 3-MA-treated IRI group presented down-regulated Caspase-3 and up-regulated Bcl-2 protein expression with comparison of IRI group (P < 0.05). CONCLUSIONS: Retina IRI-caused RGCs loss involved activated autophagy pathway and apoptosis, which could be prevented by autophagy inhibitor 3-MA. Autophagy inhibitor 3-MA may act as a potent therapeutic tool in attenuating retina IRI.