High-intensity interval resistance training (HIIRT) improves liver gluconeogenesis from lactate in Swiss mice

High-intensity physical exercise favors anaerobic glycolysis and increases lactatemia. Lactate is converted back to glucose in the liver, so that the lactate threshold, an indicator of physical performance, must be related to the gluconeogenic capacity of the liver. This research assessed the effect of a high-intensity interval resistance training (HIIRT) on liver gluconeogenesis from lactate. Swiss mice were trained (groups T) on vertical ladder with overload of 90% of their maximal load. Control animals remained untrained (groups C0 and C8). In situ liver perfusion with lactate and adrenaline was performed in rested mice after six hours of food deprivation. There were larger outputs of glucose (T6 71.90%, T8 54.53%) and pyruvate (T8 129.28%) (representative values for 4 mM lactate) in the groups trained for six or eight weeks (T6 and T8), and of glucose in the presence of adrenaline in group T8 (280%). The content of PEPCK, an important regulatory enzyme of the gluconeogenic pathway, was 69.13% higher in group T8 than in the age-matched untrained animals (C8). HIIRT augmented liver gluconeogenesis from lactate and this might improve the lactate threshold. Bullet points: The liver metabolizes lactate from muscle into glucose. Physical training may enhance the gluconeogenic capacity of the liver. As lactate clearance by the liver improves, lactate threshold is displaced to higher exercise intensities.

Subnormothermic isolated organ perfusion with Nicorandil increased cold ischemic tolerance of liver in experimental model

BACKGROUND: The cold ischemia –reperfusion injury may lead to microcirculatory disturbances, hepatocellular swelling, inflammation, and organ dysfunction. Nicorandil is an anti-ischemic, ATP-sensitive potassium (KATP) channel opener drug and has proved its effectiveness against hepatic Ischemia/Reperfusion (I/R) injury. OBJECTIVE: This study aimed to investigate the effect of Nicorandil on mitochondrial apoptosis, oxidative stress, inflammation, histopathological changes, and cold ischemic tolerance of the liver in an ex vivo experimental isolated-organ-perfusion model. METHODS: We used an ex vivo isolated rat liver perfusion system for this study. The grafts were retrieved from male Wistar rats (n = 5 in each), preserved in cold storage (CS) for 2 or 4 hours (group 1, 2), or perfused for 2 or 4 hours (group 3, 4) immediately after removal with Krebs Henseleit Buffer (KHB) solution or Nicorandil containing KHB solution under subnormothermic (22–25°C) conditions (group 5, 6). After 15 minutes incubation at room temperature, the livers were reperfused with acellular, oxygenated solution under normothermic condition for 60 minutes. RESULTS: In the Nicorandil perfused groups, significantly decreased liver enzymes, GLDH, TNF-alpha, and IL-1ß were measured from the perfusate. Antioxidant enzymactivity was higher in the perfused groups. Histopathological examination showed ameliorated tissue deterioration, preserved parenchymal structure, decreased apoptosis, and increased Bcl-2 activity in the Nicorandil perfused groups. CONCLUSIONS: Perfusion with Nicorandil containing KHB solution may increase cold ischemic tolerance of the liver via mitochondrial protection which can be a potential therapeutic target to improve graft survival during transplantation.

Isolated chemohyperthermal perfusion of the liver with melphalan in the treatment of unresectable liver metastases with uveal melanoma

Uveal melanoma belongs to rare malignant neoplasms, and the biological peculiarity of this tumor determines the high rate of distant metastasis, which reaches 60 %. Most frequently, uveal melanoma metastases are localized in the liver and have an isolated character. At the same time, despite the achievements of modern drug therapy, the treatment results of this category of patients remain unsatisfactory. Among the regional methods of treatment of metastatic uveal melanoma, surgical treatment is considered to be the most effective. Median survival rate in the group of radically operated patients (R0) is 27 months. At present, in the vast majority of cases, surgical treatment is impossible because of multiple bilobar metastasis and advanced cancer process. Median life expectancy of patients with liver metastases is only 9 months. A promising method of regional treatment of inoperable metastatic uveal melanoma is isolated liver chemoperfusion. Multidisciplinary team of Radiology Scientific Research Center and Kostroma Oncologic Dispensary for the first time in Russia presents a clinical case of a patient with isolated inoperable uveal melanoma liver metastases using an innovative method - isolated high-dose chemo hyperthermic liver perfusion with melphalan. The article describes in detail the method of the procedure, estimates immediate (partial response in 1 month after the procedure) and long-term results of the method (stabilization of the condition against the background of immunotherapy in 9 months after surgery). Based on the presented clinical observation, isolated liver chemoperfusion with melphalan for this category of patients is reasonable. However, despite the encouraging immediate results, clinical experience needs to be accumulated in order to be further evaluated in clinical trials.

Geometrical model of lobular structure and its importance for the liver perfusion analysis

A convenient geometrical description of the microvascular network is necessary for computationally efficient mathematical modelling of liver perfusion, metabolic and other physiological processes. The tissue models currently used are based on the generally accepted schematic structure of the parenchyma at the lobular level, assuming its perfect regular structure and geometrical symmetries. Hepatic lobule, portal lobule, or liver acinus are considered usually as autonomous functional units on which particular physiological problems are studied. We propose a new periodic unit—the liver representative periodic cell (LRPC) and establish its geometrical parametrization. The LRPC is constituted by two portal lobulae, such that it contains the liver acinus as a substructure. As a remarkable advantage over the classical phenomenological modelling approaches, the LRPC enables for multiscale modelling based on the periodic homogenization method. Derived macroscopic equations involve so called effective medium parameters, such as the tissue permeability, which reflect the LRPC geometry. In this way, mutual influences between the macroscopic phenomena, such as inhomogeneous perfusion, and the local processes relevant to the lobular (mesoscopic) level are respected. The LRPC based model is intended for its use within a complete hierarchical model of the whole liver. Using the Double-permeability Darcy model obtained by the homogenization, we illustrate the usefulness of the LRPC based modelling to describe the blood perfusion in the parenchyma.

Value of perfusion parameters histogram analysis of triphasic CT in differentiating intrahepatic mass forming cholangiocarcinoma from hepatocellular carcinoma

We aim to gain further insight into identifying differential perfusion parameters and corresponding histogram parameters of intrahepatic mass-forming cholangiocarcinoma (IMCC) from hepatocellular carcinomas (HCCs) on triphasic computed tomography (CT) scans. 90 patients with pathologically confirmed HCCs (n = 54) and IMCCs (n = 36) who underwent triple-phase enhanced CT imaging were included. Quantitative analysis of CT images derived from triphasic CT scans were evaluated to generate liver perfusion and histogram parameters. The differential performances, including the area under the receiver operating characteristic curve (AUC), specificity, and sensitivity were assessed. The mean value, and all thepercentiles of the arterial enhancement fraction (AEF) were significantly higher in HCCs than in IMCCs. The difference in hepatic arterial blood supply perfusion (HAP) and AEF (ΔHAP = HAPtumor − HAPliver, ΔAEF = AEFtumor − AEFliver) for the mean perfusion parameters and all percentile parameters between tumor and peripheral normal liver were significantly higher in HCCs than in IMCCs. The relative AEF (rAEF = ΔAEF/AEFliver), including the mean value and all corresponding percentile parameters were statistically significant between HCCs and IMCCs. The 10th percentiles of the ΔAEF and rAEF had the highest AUC of 0.788 for differentiating IMCC from HCC, with sensitivities and specificities of 87.0%, 83.3%, and 61.8%, 64.7%, respectively. Among all parameters, the mean value of ∆AEF, the 75th percentiles of ∆AEF and rAEF, and the 25th percentile of HFtumor exhibited the highest sensitivities of 94.4%, while the 50th percentile of rAEF had the highest specificity of 82.4%. AEF (including ΔAEF and rAEF) and the corresponding histogram parameters derived from triphasic CT scans provided useful value and facilitated the accurate discrimination between IMCCs and HCCs.

Early Assessment of Response to Radiofrequency Ablation With CT Perfusion Imaging in Rabbit VX2 Liver Tumor Model

ObjectivesTo discriminate viable tumors from benign periablational enhancement (BPE) in early stage after radiofrequency ablation (RFA) is a major confounding problem. The goal of this study is to evaluate quantitative assessment and diagnostic value of CT perfusion between viable tumors and BPE after RFA in the rabbit liver VX2 tumor model, with pathological results as the standard.MethodsTwenty-eight VX2 liver tumors were treated with RFA, on days 1, 3, 7, and 14, seven rabbits were randomly chosen for CT perfusion and performed pathology examinations immediately. The perfusion parameters along with the profile of time-density curves (TDCs) and pseudo-color images of the parameters were observed in both BPE and viable tumors, then compared with the pathology results. The perfusion parameters included blood flow (BF), blood volume (BV), time to peak (TTP), permeability (P), arterial liver perfusion (ALP), portal venous perfusion (PVP) and hepatic perfusion index (HPI).ResultsA total of 26/28 rabbits successfully underwent CT perfusion, while 6/26 lesions were confirmed to be viable tumors. The TDCs of BPE were mainly speed-up platform curves (15/26), while the viable tumors showed mainly speed-up speed-down (3/6) and speed-up platform (2/6) curves. The PVP values were significantly higher, and the HPI values were significantly lower for BPE at all time points than viable tumors (P < 0.05). Both of PVP value and HPI value have high efficiency for the differential diagnosis of the viable tumors and BPE at each time point. These characteristics of CT perfusion parameters were consistent with pathological changes.ConclusionsThe TDCs, PVP and HPI have the potential to indicate BPE and viable tumors effectively early after RFA treatment, the results were highly consistent with pathology. CT perfusion has advantages with great efficacy in monitoring the therapeutic effect early after RFA treatment.

Cytochrome P450 2E1 Predicts Liver Retrieval from Donation After Circulatory Death Using Air-Ventilated Normothermic Machine Perfusion

The optimal oxygen concentration is unclear for normothermic machine perfusion (NMP) of livers from donation after circulatory death donors (DCD). Our purposes were to investigate the effect of air-ventilated NMP on liver retrieval from DCD rats, and to analyze the underlying mechanism. Normothermic liver perfusion was performed using the NMP system with either air ventilation or oxygen ventilation for 2h in the rat liver following warm ischemia and cold ischemia preservation. Proteomics and metabolomics were used to reveal the significant molecular networks. The bioinformation analysis was validated by administering peroxisome proliferator activator receptor-γ (PPARγ) antagonist and agonist via ex vivo perfusion circuit in the air-ventilated NMP. Results showed that air-ventilated NMP conferred a better functional retrieval and a less inflammatory response in the rat DCD liver; integrated proteomics and metabolomics analysis indicated that intrahepatic docosapentaenoic acid (DPA) downregulation and upregulation of cytochrome P450 2E1 (CYP2E1) expression and activity were associated with DCD liver retrieval with air-ventilated NMP; PPARγ antagonist worsened liver function under air-oxygenated NMP whereas PPARγ agonist played the opposite role. In conclusion, air-ventilated NMP confers a better liver retrieval from DCD rats through the DAP-PPARγ-CYP2E1 axis; CYP2E1 activity provides a biomarker of liver retrieval from DCD.

Molecular and proteomic signatures associated with preservation related graft injury: insight from human liver normothermic machine perfusion (NMP)

Fungai Dengu1; Sadr Shaheed1; Letizia Lo Faro1; Adam Thorne1; Honglei Huang1; Peter Friend1,Rutger Ploeg1. 1. Oxford Organ Perfusion Lab, Nuffield Department of Surgical Sciences and Oxford BiomedicalResearch Centre, University of Oxford, Oxford, UK BackgroundContinuous liver NMP is a novel technology associated with safe extension of organ preservation time, increased organ utilisation and reduced early graft injury1. Increasingly, it is utilised as a ‘back to base’ application with cold storage for organ transport and NMP initiated at the implanting centre prior to transplantation2. We aimed to evaluate the impact of additional cold ischaemia time (CIT) on the proteomic and molecular signature of NMP livers. Methods Liver tissue samples (N= 57) from a prospective clinical trial of ‘back to base’ NMP were analysed. Collection occurred at the end of cold storage (LT1), end of NMP/total preservation (LT2) and after organ reperfusion (LT3). Unbiased, label-free-quantitative (LFQ) proteomic analysis was conducted using liquid chromatography with tandem mass spectrometry and trapped ion mobility spectrometry (TIMS) to time-of-flight (TOF) mass analysis (LC-MS/MS TIMS-TOF). Differential expression and Gene Ontology/Pathway analysis were performed. Results LT2 samples with prolonged CIT (>6hr) prior to NMP had significant differential expression of proteins associated with liver-specific oxidative stress, cellular haemostasis and removal of damaged or misfolded proteins (e.g. CYP3A5, PSMB1). LT3 samples, similarly, had reduced proteins involved in autophagy and cell-cycle regulation (e.g. STBD1, CD2AP, GADD45GIP1,) and increased expression of proteins involved in neutrophil chemotaxis, adhesion and aggregation (e.g. S100A9). Discussion The molecular signature of grafts at LT2 and LT3 varies depending on the length of CIT prior to NMP. Further exploration of the molecular signatures associated with preservation related graft injury is required to determine how best to apply this novel technology clinically. References: 1. Nasralla, D. et al. A randomized trial of normothermic preservation in liver transplantation. Nature 557, 50–56 (2018).2. Ceresa, C. D. L. et al. Transient Cold Storage Prior to Normothermic Liver Perfusion May Facilitate Adoption of a Novel Technology. Liver Transplant. lt.25584 (2019).doi:10.1002/lt.25584