Macro-indentation testing of soft biological materials and assessment of hyper-elastic material models from inverse finite element analysis

Mechanical characterization of hydrogels and ultra-soft tissues is a challenging task both from an experimental and material parameter estimation perspective because they are much softer than many biological materials, ceramics, or polymers. The elastic modulus of such materials is within the 1 - 100 kPa range, behaving as a hyperelastic solid with strain hardening capability at large strains. In the current study, indentation experiments have been performed on agarose hydrogels, bovine liver, and bovine lymph node specimens. This work reports on the reliable determination of the elastic modulus by indentation experiments carried out at the macro-scale (mm) using a spherical indenter. However, parameter identification of the hyperelastic material properties usually requires an inverse finite element analysis due to the lack of an analytical contact model of the indentation test. Hence a comprehensive study on the spherical indentation of hyperelastic soft materials is carried out through robust computational analysis. Neo-Hookean and first-order Ogden hyperelastic material models were found to be most suitable. A case study on known anisotropic hyperelastic material showed the inability of the inverse finite element method to uniquely identify the whole material parameter set.

Trace element bioaccumulation in the hepatic tissue of juvenile green turtles (Chelonia mydas) stranded along the Campos and Espírito Santo basins, southeastern Brazil

This study analyzed the concentrations of 15 (Al, As, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se, V, Zn) toxicologically important trace elements in the livers of 110 green turtles stranded in two areas of the Brazilian coast. These areas are essential for the refuge, feeding, and reproduction of the species, and the information obtained is intended to support the development of conservation strategies. Higher concentrations were observed in the Região dos Lagos, RJ in almost all elements, except for Al, Mo, Pb, and V. This location showed statistically higher differences in the concentrations of Cd (4.66 ± 2.33 μg.g-1), Fe (846.62 ± 583.06 μg.g-1), and Zn (27.17 ± 10.90 μg.g-1). The differences in trace element concentration patterns between the two study areas are likely influenced by multiple factors, including the bioavailability of trace elements, oceanic upwelling events, anthropogenic activities, habitat characteristics, and organism-specific metabolic processes.

Analysis of decellularized mouse liver fragment and its recellularization with human endometrial mesenchymal cells as a candidate for clinical usage

Decellularized tissue has been used as a natural extracellular matrix (ECM) or bioactive biomaterial for tissue engineering. The present study aims to compare and analyze different decellularization protocols for mouse liver fragments and cell seeding and attachment in the created scaffold using human endometrial mesenchymal cells (hEMCs).After collecting and dissecting the mouse liver into small fragments, they were decellularized by Triton X-100 and six concentrations of sodium dodecyl sulfate (SDS; 0.025, 0.05, 0.1, 0.25, 0.5, and 1%) at different exposure times. The morphology and DNA content of decellularized tissues were studied, and the group with better morphology and lower DNA content was selected for additional assessments. Masson's tri-chrome and periodic acid Schiff staining were performed to evaluate ECM materials. Raman confocal spectroscopy analysis was used to quantify the amount of collagen type I, III and IV, glycosaminoglycans and elastin. Scanning electron microscopy and MTT assay were applied to assess the ultrastructure and porosity and cytotoxicity of decellularized scaffolds, respectively. In the final step, hEMCs were seeded on the decellularized scaffold and cultured for one week, and finally the cell attachment and homing were studied morphologically.The treated group with 0.1% SDS for 24 h showed a well preserved ECM morphology similar to native control and showing the minimum level of DNA. Raman spectroscopy results demonstrated that the amount of collagen type I and IV was not significantly changed in this group compared to the control, but a significant reduction in collagen III and elastin protein levels was seen (P < 0.001). The micrographs showed a porous ECM in decellularized sample similar to the native control with the range of 2.25 µm to 7.86 µm. After cell seeding, the infiltration and migration of cells in different areas of the scaffold were seen. In conclusion, this combined protocol for mouse liver decellularization is effective and its recellularization with hEMCs could be suitable for clinical applications in the future.

Modeling and ex vivo experimental validation of liver tissue carbonization with laser ablation

OBJECTIVE

The purpose of this study was to model the process of liver tissue carbonization with laser ablation (LA).

METHODS

A dynamic heat source model was proposed and combined with the light distribution model as well as bioheat transfer model to predict the development of tissue carbonization with laser ablation (LA) using an ex vivo porcine liver tissue model. An ex vivo laser ablation experiment with porcine liver tissues using a custom-made 1064 nm bare fiber was then used to verify the simulation results at 3, 5, and 7 W laser administrations for 5 min. The spatiotemporal temperature distribution was monitored by measuring the temperature changes at three points close the fiber during LA. Both the experiment and simulation of the temperature, tissue carbonization zone, and ablation zone were then compared.

RESULTS

Four stages were recognized in the development of liver tissue carbonization during LA. The growth of the carbonization zone along the fiber axial and radial directions were different in the four stages. The carbonization zone along the fiber axial direction (L2) grew in the four stages with a sharp increase in the initial period and a minor increase in Stage 4. However, the change in the carbonization zone along the fiber radial direction (D2) increased dramatically (Stage 1) to a long-time plateau (Stages 2 and 3) followed by a slow growth in Stage 4. An acceptable agreement between the computer simulation and ex vivo experiment in the temperature changes at the three points was found at all three testing laser administrations. A similar result was also obtained for the dimensions of coagulation zone and ablation zone between the computer simulation and ex vivo experiment (carbonization zone: 2.99± 0.10 vs. 2.78 mm², 67.39± 0.09 vs. 63.53 mm², and 90.53± 0.11 vs. 85.15 mm²; ablation zone: 68.95± 0.28 vs. 65.29 mm², 182.11± 0.24 vs. 213.81 mm², and 244.80± 0.06 vs. 251.79 mm² at 3, 5, and 7 W, respectively).

CONCLUSION

This study demonstrates that the proposed dynamic heat source model combined with the light distribution model as well as bioheat transfer model can predict the development of liver tissue carbonization with an acceptable accuracy. This study contributes to an improved understanding of the LA process in the treatment of liver tumors.

Human Chr18 transcriptome dataset combined from the Illumina HiSeq, ONT MinION, and qPCR data

The chromosome-centric dataset was created by applying several technologies of transcriptome profiling. The described dataset is available at NCBI repository (BioProject ID PRJNA635536). The dataset referred to the same type of tissue, cell lines, transcriptome sequencing technologies, and was accomplished in a period of 8 years (the first data were obtained in 2013 while the last ones - in 2020). The high-throughput sequencing technologies were employed along with the quantitative PCR (qPCR) approach, for data generation using the gene expression level assessment. qPCR was performed for a limited group of genes, encoded on human chromosome 18, for the Russian part of the Chromosome-Centric Human Proteome Project. The data of high-throughput sequencing are provided as Excel spreadsheets, where the data on FPKM and TMP values were evaluated for the whole transcriptome with both Illumina HiSeq and Oxford Nanopore Technologies MinION sequencing.

Protective effects of a mitochondria-targeted small peptide SS31 against hyperglycemia-induced mitochondrial abnormalities in the liver tissues of diabetic mice, Tallyho/JngJ mice

Type 2 Diabetes mellitus (T2DM) has become a major public health issue associated with a high risk of late-onset Alzheimer's disease (LOAD). Mitochondrial dysfunction is one of the molecular events that occur in the LOAD pathophysiology. The present study was planned to investigate the molecular alterations induced by hyperglycemia in the mitochondria of diabetic mice and further explore the possible ameliorative role of the mitochondria-targeted small peptide, SS31 in diabetic mice. For this purpose, we used a polygenic mouse model of type 2 diabetes, TALLYHO/JngJ (TH), and nondiabetic, SWR/J mice strains. The diabetic status in TH mice was confirmed at 8 weeks of age. The 24 weeks old experimental animals were segregated into three groups: Non-diabetic controls (SWR/J mice), diabetic (TH mice) and, SS31 treated diabetic TH mice. The mRNA and protein expression levels of mitochondrial proteins were investigated in all the study groups in the liver tissues using qPCR and immunoblot analysis. Also, the mitochondrial functions including H2O2 production, ATP generation, and lipid peroxidation were assessed in all the groups. Mitochondrial dysfunction was observed in TH mice as evident by significantly elevated H2O2 production, lipid peroxidation, and reduced ATP production. The mRNA expression and Western blot analysis of mitochondrial dynamics (Drp1 and Fis1 - fission; Mfn1, Mfn2, and Opa1 -fusion), and biogenesis (PGC-1α, Nrf1, Nrf2, and TFAM) genes were significantly altered in diabetic TH mice. Furthermore, SS31 treatment significantly reduced the mitochondrial abnormalities and restore mitochondrial functions in diabetic TH mice.

Distinct stratification of normal liver, hepatocellular carcinoma (HCC), and anticancer nanomedicine-treated- tumor tissues by Raman fingerprinting for HCC therapeutic monitoring

Hepatocellular carcinomas (HCCs) are highly vascularized neoplasms with poor prognosis. Nanomedicine possesses great potential to deliver therapeutics and diagnostics. The new aspect of this study is that we have monitored, for the first time, the Raman responses to microtubule targeted vascular disrupting agents (MTVDA), MTVDA encapsulated non-targeted, and targeted cetuximab polymeric nanocomplexes delivery of combinatorial therapeutics in HCC tumor tissues of mice. Biochemical differences majorly demarcated apoptotic lipid bodies, and characteristic amide-I features. HCC tumor and healthy liver tissues could be stratified. Raman spectroscopy served as an excellent, rapid, sensitive and cost-effective approach for anticancer nanomedicine distinct stratification of MTVDA encapsulated targeted cetuximab polymeric nanocomplex combinatorials, a significant potential for HCC therapeutic monitoring.

Acorbine, a Corbicula japonica-derived tripeptide containing non-proteinogenic amino acids, suppresses ethanol-induced liver injury

Since ancient times, Corbicula extract has been believed in Japan to have hepatoprotective effects, but it remains unclear whether these claims are true, and if so, which component is responsible for hepatoprotection. In this study, we showed that Corbicula extract exerted a protective effect against liver damage. Recent work identified acorbine (β-alanyl-ornithyl-ornithine), a novel tripeptide containing non-proteinogenic amino acids, in the extract of Corbicula japonica. Synthesized acorbine cured alcohol-induced liver damage in mice. In addition, acorbine purified from Corbicula extract exerted a protective effect against alcohol-induced hepatotoxicity in a culture liver model derived from mouse ES/iPS cells. Thus, acorbine is one of the components of Corbicula extract that protects hepatocytes against ethanol-induced death.

Cell sheet tissue engineering for scaffold-free three-dimensional (3D) tissue reconstruction

Three-dimensional (3D) reconstruction of highly functional tissues is of great importance in advancing the clinical benefit of tissue engineering and regenerative medicine. In the last quarter century, many studies have found that by engineering a 3D microenvironment that resembles the in vivo tissue condition, cells exhibit behaviors and functions that reflect those of native tissue. Biomaterial scaffolds are a central technology for providing 3D microenvironments in vitro, and, in conjunction with diverse design and cell seeding advents, have produced highly functional and complex 3D tissues. Here, we describe a new approach to creating 3D cell-dense tissue-like constructs without a biomaterial scaffold. Cell sheet technology with cell sheet layering strategies generates highly cell dense, engineered tissue capable of direct crosstalk with the tissue-engraftment surface, in addition to paracrine-mediated signaling. In this chapter, we will introduce methods of reconstructing 3D tissue using cell sheet technology and the advantages of a scaffold-free design.

Liver changes induced by cadmium poisoning distinguished by confocal Raman imaging

Heavy metal pollution has become an important issue threatening human health and the liver is a very important metabolic organ. Here, we use label-free Raman confocal imaging to study the alterations of the liver tissue after cadmium pollution. Raman imaging has been performed on 100μmx100μm liver tissues to study the distribution of important macromolecules and the average Raman spectrum of the entire region has been used to characterize and quantize the change of biochemical compositions in liver tissue. The poisoned livers displayed a significant decrease in the intensity of 748 cm^-1, 1128 cm^-1 and 1585 cm^-1 bands of cytochrome C, in comparison to the control. The collagen peak at 1082 cm^-1 is significantly higher than that of control, suggesting the increasing fibrosis of Cd liver tissues. To confirm the results, we selected a 30μmx15μm liver cell area for high-resolution Raman imaging. We observed a substantial increase of lipids and proteins at specific points of hepatocytes. The confocal Raman imaging of liver tissues provided a unique tool to better understand disease-induced changes in the biochemical phenotype of primary liver tissues. Our study provides valuable references as in vitro models for studying Cd accumulation and toxicity in human liver.

Hepatotoxic effects of inhalation exposure to polycyclic aromatic hydrocarbons on lipid metabolism of C57BL/6 mice

Inhalation from ambient air and cigarette smoke is a common route of human exposure to polycyclic aromatic hydrocarbons (PAHs). Little information is available regarding hepatotoxicities of inhaled PAHs so for. In this study, we evaluated the toxic effects of intratracheally instilled benzo[a]pyrene (B[a]P) on hepatic lipid metabolism of C57BL/6 mice at relevant environmental exposure levels by using two different mass-based lipidomics approaches. The results of mass spectrometry imaging analysis showed that both the abundance and spatial distribution of several lysophosphatidylcholine (LysoPC), phosphatidylcholine (PC) and sphingomyelin (SM) in the liver section were different and changed after inhalation exposure to B[a]P. Liquid chromatography coupled with mass spectrometry-based lipidomics analysis and multivariate statistical analysis found that B[a]P exposure markedly altered glycerophospholipids, glycerolipids, and fatty acid metabolism in the mouse liver, with increasing of triacylglycerol (TG), phosphatidylinositol (PI) and PC, and decreasing of LysoPCs phosphatidylethanolamines (PEs), lysophosphatidylethanolamine (LysoPEs), free fatty acids (FFAs) and eicosanoids. B[a]P-induced lipid metabolic disorders showed a time-dependent effect, which generated three response trajectories with different change trends. Consequently, B[a]P exposure induced alteration of hepatic lipids by promoting the uptake from blood or the biosynthesis and transformation in the liver, might contribute to non-alcoholic fatty liver disease, hepatocyte membrane injury, inflammation, and signal system disturbance.

The potential of antioxidant-rich Maoberry (Antidesma bunius) extract on fat metabolism in liver tissues of rats fed a high-fat diet

Backgound

Obesity and dyslipidemia are major risk factors associated with non-alcoholic fatty liver disease (NAFLD). NAFLD refers to the accumulation of fat in more than 5% of the liver without alcohol consumption. NAFLD is the most common liver disease and is rapidly becoming a global public health problem. Maoberry (Antidesma bunius) is a fruit rich in antioxidants, especially phenolic compounds, which are reported to have benefits for patients with NAFLD.

Methods

We evaluated the effect of Maoberry extract on fat metabolism in liver tissues of high fat diet–induced rats. Five (5) groups (n = 12) of male Sprague-Dawley (SD) rats were divided into those given a high fat diet with no treatment (HF), different dosages of Maoberry extracts (0.38 [ML], 0.76 [MM) and 1.52 [MH] g/kg body weight) and 10 mg/kg statin (STAT). The rats were fed a high fat diet for 4 weeks to induce obesity and subsequently continued more for 12 weeks with treatments of Maoberry extracts or STAT. The levels of triglyceride, liver enzymes, oxidative stress and inflammation markers, triglyceride synthesis regulators, and pathology of the liver in high fat diet-induced rats were investigated.

Results

Feeding Maoberry extract in MH groups resulted in decreasing levels of serum alanine aminotransferase (ALT), liver triglyceride, liver thiobarbituric acid reactive substances (TBARS) and mRNA expression of tumour necrosis factor (TNF)-α, interleukin (IL)-6, glycerol-3-phosphate acyltransferase (GPAT)-1 and acetyl-coenzyme A carboxylase (ACC) compared with the HF group (P < 0.05). Moreover, histopathological study of the liver showed reduced fat droplets in the Maoberry extract treatment groups, especially in MH groups and STAT treatment groups.

Conclusions

The improvements of fat metabolism in liver tissues of rats fed a high-fat diet were observed in Maoberry extracts treatment groups. The underline mechanism that link to fat metabolism might be through the process accompanied with down-regulated the gene expression of key enzymes of lipid production, antioxidant activity, and anti-inflammation properties of Maoberry extracts which contains high levels of phenolic and flavonoid compounds.

Ex vivo validation of microwave thermal ablation simulation using different flow coefficients in the porcine liver

The purpose of the study was to validate the simulation model for a microwave thermal ablation in ex vivo liver tissue. The study aims to show that heat transfer due to the flow of tissue water during ablation in ex vivo tissue is not negligible. Ablation experiments were performed in ex vivo porcine liver with microwave powers of 60 W to 100 W. During the procedure, the temperature was recorded in the liver sample at different distances to the applicator using a fiber-optic thermometer. The position of the probes was identified by CT imaging and transferred to the simulation. The simulation of the heat distribution in the liver tissue was carried out with the software CST Studio Suite. The results of the simulation with different flow coefficients were compared with the results of the ablation experiments using the Bland-Altman analysis. The analysis showed that the flow coefficient of 90,000 W/(K*m³) can be considered as the most suitable value for clinically used powers. The presented simulation model can be used to calculate the temperature distribution for microwave ablation in ex vivo liver tissue.

Expression of selected genes isolated from whole blood, liver and obex in lambs with experimental classical scrapie and healthy controls, showing a systemic innate immune response at the clinical end-stage

BACKGROUND

Incubation period, disease progression, pathology and clinical presentation of classical scrapie in sheep are highly dependent on PRNP genotype, time and route of inoculation and prion strain. Our experimental model with pre-colostrum inoculation of homozygous VRQ lambs has shown to be an effective model with extensive PrPSc dissemination in lymphatic tissue and a short incubation period with severe clinical disease. Serum protein analysis has shown an elevation of acute phase proteins in the clinical stages of this experimental model, and here, we investigate changes in gene expression in whole blood, liver and brain.

RESULTS

The animals in the scrapie group showed severe signs of illness 22 weeks post inoculation necessitating euthanasia at 23 weeks post inoculation. This severe clinical presentation was accompanied by changes in expression of several genes. The following genes were differentially expressed in whole blood: TLR2, TLR4, C3, IL1B, LF and SAA, in liver tissue, the following genes differentially expressed: TNF-α, SAA, HP, CP, AAT, TTR and TF, and in the brain tissue, the following genes were differentially expressed: HP, CP, ALB and TTR.

CONCLUSIONS

We report a strong and evident transcriptional innate immune response in the terminal stage of classical scrapie in these animals. The PRNP genotype and time of inoculation are believed to contribute to the clinical presentation, including the extensive dissemination of PrPSc throughout the lymphatic tissue.

3D human liver tissue from pluripotent stem cells displays stable phenotype in vitro and supports compromised liver function in vivo

Liver disease is an escalating global health issue. While liver transplantation is an effective mode of therapy, patient mortality has increased due to the shortage of donor organs. Developing renewable sources of human liver tissue is therefore attractive. Pluripotent stem cell-derived liver tissue represents a potential alternative to cadaver derived hepatocytes and whole organ transplant. At present, two-dimensional differentiation procedures deliver tissue lacking certain functions and long-term stability. Efforts to overcome these limiting factors have led to the building of three-dimensional (3D) cellular aggregates. Although enabling for the field, their widespread application is limited due to their reliance on variable biological components. Our studies focused on the development of 3D liver tissue under defined conditions. In vitro generated 3D tissues exhibited stable phenotype for over 1 year in culture, providing an attractive resource for long-term in vitro studies. Moreover, 3D derived tissue provided critical liver support in two animal models, including immunocompetent recipients. Therefore, we believe that our study provides stable human tissue to better model liver biology 'in the dish', and in the future may permit the support of compromised liver function in humans.

[Effect of Wnt/β-catenin signal regulating EMT level on the differentiation of mouse ESC to liver tissue]

Objective: To study embryonic stem cell (ESC) differentiation into liver tissue structure from the perspective of epithelial mesenchymal transition (EMT). Methods: ESC of Balb/c mice was selected to induced into hepatic cell using hepatocyte growth factor (HGF), fibroblast growth factor (FGF) in vitro, and at the time points of metaphase (13 d) and maturity (17 d) of differentiation, dynamic inhibition of Wnt/β-catenin signal was made to reduce the level of EMT. Finally, three-dimensional organization structure growth of the differentiation cells was observed in the differentiation system.Expressions of the liver cells vascular markers[albumin (Alb) and vascular endothelial growth factor (VEGFR)]were detected. Results: During the differentiation of ESC, the level of early EMT in the experimental group and the control group was not significantly different. The level of mid-late EMT in the experiment group was significantly lower than the control group. On the day 18 and 20 of differentiation, the relative mRNA expression level of E-cadherin was 0.61±0.15 and 0.47±0.05 in the experimental group, and 0.07±0.05 and 0 in the control group, respectively.The expression level of ALB/AFP/CK8/CK19 in the experimental group was generally higher than that of the control group in the same period, while CD31/VEGFR1 markers in the experimental group decreased more slowly in the late period of differentiation compared with the control group. In the supernatant of ESC culture, the Alb of the experimental group could be detected onday 7, and the concentration was (0.32±0.02) mg/L, while Alb in the control group was (0.19±0.05) mg/L. Urea in the experimental group could be detected on the day 13, and the concentration was (8.7 ±1.0) μmol/L, and the urea concentration of the control group was (3.1±1.2) μmol/L. The concentration of Alb and urea in the culture supernatant of ESC differentiation system increased significantly with the prolongation of the differentiation time, and the Alb and urea concentrations in the experimental group were significantly higher than those in the control group at the same time period. In addition, the differentiated cells in the experimental group could maintain the growth of three-dimensional tissue, while the differentiated cells in the control group eventually showed a single cell state. The expression of hepatic and vascular cell markers could be detected in the experimental group. Immunofluorescence results showed that the hepatocytes and vascular structures were tightly arranged. HE staining showed the formation of hepatic lobular structure, while the control group had no vascular component markers. Conclusion: The differentiation of ESC into liver tissue can be effectively promoted by decreasing the level of EMT at the mid-late stage of ESC differentiation.

The estimation method of friction in unconfined compression tests of liver tissue

In traditional unconfined compression tests, the friction between platform and specimen is often considered negligible or minimized by lubrication or other means. However, friction can affect the estimation of material parameters. The percentage difference in radial deformation was investigated in this study. A novel friction estimation method was established and verified using a finite element method. The proposed method was based on the radial deformation during the compression process. Three different hyperelastic material parameters of liver tissue were applied in the simulations. The hyperelastic parameters H1 were obtained by no-slip compression tests, while the others were extracted from the literature. The results showed that the percentage difference in radial deformation was mainly influenced by the friction coefficient and diameter-to-height ( d/ h) ratio of the specimen in unconfined compression tests. The percentage difference increased as the friction coefficient and d/ h increased. Different d/ h and friction coefficient values were tested to validate the proposed method, and the accuracy was estimated to exceed 86%. An optimization strategy for material parameters in unconfined compression tests was proposed accordingly.

Determination of 20, 25-diazacholesterol in avian matrices by high performance liquid chromatography/tandem mass spectrometry

Wildlife contraceptives are an emerging tool for minimizing human-wildlife conflicts. One promising avian contraceptive compound, 20,25-diazacholesterol (DAC), reduces fertility by inhibiting cholesterol synthesis. A reliable analytical method for DAC was required in support of its registration for use as a reproductive control agent in pest bird species. A liquid chromatographic method employing tandem mass spectrometry (LC-MS/MS) was developed for the analysis of tissue extracts following solid phase extraction clean-up. Tissues analyzed were whole body samples from crows, monk parakeets, and quails and liver samples from crows and quails. Excellent sensitivity and selectivity was afforded by tandem mass spectrometry. The method accuracy of DAC from various tissue samples fortified at parts-per-million (ppm) and parts-per-billion (ppb) concentrations was high (>90%) with excellent precision (<10% relative standard deviation). Lower limits of detection were excellent in all tissues types, ranging from 1 to 11ppb in whole body matrices and 9.9-34ppb in liver matrices.

Intrahepatic Vγ9Vδ2 T-cells from HCV-infected patients show an exhausted phenotype but can inhibit HCV replication

Hepatitis C virus (HCV) persistence results from inefficiencies of both innate and adaptive immune responses to eradicate the infection. A functional impairment of circulating Vγ9Vδ2 T-cells was described but few data are available on Vγ9Vδ2 T-cells in the liver that, however, represents the battlefield in the HCV/host interaction. Aim of this work was to compare circulating and intrahepatic Vγ9Vδ2 T-cells in chronic HCV-infected patients (HCV^pos) and in HCV-negative (HCV^neg) subjects. Phenotypic and functional analysis was performed by flow cytometry. Anti-HCV activity was analyzed by using an in vitro autologous liver culture system. Independently from HCV infection, the liver was enriched of Vγ9Vδ2 T-cells expressing an effector/activated phenotype. In contrast, an enrichment of PD-1 expressing Vγ9Vδ2 T-cells was observed both in the peripheral blood and in the liver of HCV^pos patients, probably due to a persistent antigenic stimulation. Moreover, a lower frequency of IFN-γ producing Vγ9Vδ2 T-cells was observed in the liver of HCV^pos patients, suggesting a functional impairment in the cytokine production in HCV^pos liver. Despite this hypo-responsiveness, intrahepatic Vγ9Vδ2 T-cells are able to exert an anti-HCV activity after specific stimulation. Altogether, our data show that HCV infection induced a dysregulation of intrahepatic Vγ9Vδ2 T cells that maintain their anti-HCV activity after specific stimulation. A study aimed to evaluate the mechanisms of the antiviral activity may be useful to identify new pathways able to improve Vγ9Vδ2 T-cells intrahepatic function during HCV infection.

Validation of a mathematical model for laser-induced thermotherapy in liver tissue

The purpose of the study was to develop a simulation approach for laser-induced thermotherapy (LITT) that is based on mathematical models for radiation transport, heat transport, and tissue damage. The LITT ablation was applied to ex vivo pig liver tissue. Experiments were repeated with different laser powers, i.e., 22-34 W, and flow rates of the cooling water in the applicator system, i.e., 47-92 ml/min. During the procedure, the temperature was measured in the liver sample at different distances to the applicator as well as in the cooling circuit using a fiber optic thermometer. For validation, the simulation results were compared with the results of the laser ablation experiments in the ex vivo pig liver samples. The simulated and measured temperature curves presented a relatively good agreement. The Bland-Altman plot showed an average of temperature differences of -0.13 ^∘C and 95%-limits-of-agreement of ±7.11 ^∘C. The standard deviation amounted to ±3.63 ^∘C. The accuracy of the developed simulation is comparable with the accuracy of the MR thermometry reported in other clinical studies. The simulation showed a significant potential for the application in treatment planning.

Autophagy response in the liver of pigeon exposed to avermectin

Pesticide residues are an important aspect of environmental pollution. Environmental avermectin residues have produced adverse effects in organisms. Many pesticides exert their toxic effects via the mechanism of autophagy. The purpose of this study was to examine the changes in autophagy levels and in autophagy-related genes, including LC3, Beclin 1, Dynein, ATG5, TORC1, and TORC2, resulting from exposure to subchronic levels of AVM in liver tissue in the king pigeon model. We observed abundant autophagic vacuoles with extensively degraded organelles, autophagosomal vacuoles, secondary lysosomes, and double-membrane structures in the liver. The expression levels of the autophagy-related genes LC3-I, LC3-II, Beclin 1, ATG5, and Dynein were up-regulated; however, TORC1 and TORC2 expression levels were down-regulated. These changes occurred in a concentration-dependent manner after AVM exposure for 30, 60, and 90 days in pigeons. Taken together, these results suggested that AVM increased the autophagic flux and that upregulation of autophagy might be closely related to the hepatotoxicity of AVM in birds.

Proteomic analysis of physiological function response to hot summer in liver from lactating dairy cows

Lactation performance of dairy cattle is susceptible to heat stress. The liver is one of the most crucial organs affected by high temperature in dairy cows. However, the physiological adaption by the liver to hot summer conditions has not been well elucidated in lactating dairy cows. In the present study, proteomic analysis of the liver in dairy cows in spring and hot summer was performed using a label-free method. In total, 127 differentially expressed proteins were identified; most of the upregulated proteins were involved in protein metabolic processes and responses to stimuli, whereas most of the downregulated proteins were related to oxidation-reduction. Pathway analysis indicated that 3 upregulated heat stress proteins (HSP90α, HSP90β, and endoplasmin) were enriched in the NOD-like receptor signaling pathway, whereas several downregulated NADH dehydrogenase proteins were involved in the oxidative phosphorylation pathway. The protein-protein interaction network indicated that several upregulated HSPs (HSP90α, HSP90β, and GRP78) were involved in more interactions than other proteins and were thus considered as central hub nodes. Our findings provide novel insights into the physiological adaption of liver function in lactating dairy cows to natural high temperature.

Isolation of GMP Grade Human Hepatocytes from Remnant Liver Tissue of Living Donor Liver Transplantation

For the purpose of clinical research of hepatocyte transplantation, procedures for isolation, cryopreservation, thawing, and functional assessment of hepatocytes are described. Although demands for human hepatocytes are increasing in not only cell therapy but also drug development, it is highly difficult to obtain good lots of hepatocytes from human liver tissue. This chapter describes essential issues such as alleviation of warm ischemia, prevention of shear stress, optimization of cryopreservation, and functional assessment, along with securement of quality. All procedures described here are compliant with good manufacturing procedure (GMP) in cell processing facility, approved by the act on measures to ensure safety of regenerative medicine and ethical regulations in Japan.

Duodenal-Jejunal Bypass Surgery Ameliorates Glucose Homeostasis and Reduces Endoplasmic Reticulum Stress in the Liver Tissue in a Diabetic Rat Model

BACKGROUND

Duodenal-jejunal bypass (DJB) has been shown to be an effective surgical treatment for type 2 diabetes mellitus (T2DM). However, the underlying mechanisms are poorly understood. Recently, accumulating evidences suggest that endoplasmic reticulum (ER) stress plays an important role in the development of insulin resistance in T2DM. The present study was designed to investigate the effect of DJB on glucose homeostasis, the ER stress state in the liver tissue, and the involving signaling independently of weight loss.

METHODS

Thirty adult male T2DM Sprague-Dawley (SD) rats induced by high-fat diet and low dose of streptozotocin (STZ) were randomly divided into DJB and sham groups. Ten age-matched male SD rats were assigned as the control group. The parameters of body weight and calorie intake were measured at indicated time points. The glucose tolerance and insulin resistance were detected to evaluate the glucose homeostasis. Serum insulin was determined by enzyme-linked immunosorbent assay (ELISA). The markers of ER stress, the activity of c-Jun N-terminal kinase (JNK) and serine phosphorylation of insulin receptor substrate 1 (IRS-1) in the liver tissue, were determined by Western blotting.

RESULTS

DJB induced significant improvements in glucose homeostasis and insulin sensitivity, but without weight loss. DJB improved the ER stress state indicated by decreased protein kinase RNA (PKR)-like ER protein kinase (PERK) and inositol-requiring enzyme 1 (IRE-1) phosphorylation in the liver tissue. The JNK activity and serine phosphorylation of IRS-1 in the liver tissue were significantly reduced after DJB.

CONCLUSIONS

DJB ameliorates glucose homeostasis. Meanwhile, our study helps to reveal that the reduced hepatic ER stress and the decreased JNK activity may contribute to the improved glucose homeostasis after DJB.

Hypoglycemic effect of D-chiro-inositol in type 2 diabetes mellitus rats through the PI3K/Akt signaling pathway

In this investigation, a model of type 2 diabetes mellitus (T2DM) was used on Sprague-Dawley (SD) rats to clarify more details of the mechanism in the therapy of T2DM. D-chiro-inositol (DCI) was administrated to the diabetic rats as two doses [30, 60 mg/(kg·body weight·day)]. The biochemical indices revealed that DCI had a positive effect on hypoglycemic activity and promoted the glycogen synthesis. The rats in DCI high-dosage group had a blood glucose reduction rate of 21.5% after 5 weeks of treatment, and had insulin content in serum about 15.3 ± 2.37 mIU/L which was significantly decreased than diabetes control group. Real-time polymerase chain reaction (RT-PCR) results revealed that DCI gave a positive regulation on glycogen synthase (GS) and protein glucose transporter-4 (Glut4). Western blotting suggested that DCI could up-regulated the expression of the phosphatidylinositol-3-kinase (PI3K) p85, PI3Kp110, GS as well as the phosphorylation of protein kinase B (Akt) both in the liver and the skeletal muscle. The results also revealed that DCI enhanced the Glut4 expression on skeletal muscle. Above all, DCI played a positive role in regulating insulin-mediated glucose uptake through the PI3K/Akt signaling pathway in T2DM rats.

Expression of connective tissue growth factor in the livers of non-viral hepatocellular carcinoma patients with metabolic risk factors

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) associated with metabolic risk factors, such as diabetes and obesity, has been increasing. However, the underlying mechanism that links these diseases remains unclear.

METHODS

We performed genome-wide expression analysis of human liver tissues of non-viral HCC patients with or without metabolic risk factors. The upregulated genes that associated with diabetes and obesity were investigated by in vitro and in vivo experiments, and immunohistochemistry of human liver tissues was performed.

RESULTS

Among the upregulated genes, connective tissue growth factor (CTGF) expression was induced to a greater extent by combined glucose and insulin administration to human hepatoma cells. Genome-wide expression analysis revealed upregulation of a chemokine network in CTGF-overexpressing hepatoma cells, which displayed an increased ability to induce in vitro activation of macrophages, and in vivo infiltration of liver macrophages. Immunohistochemistry of human liver tissues validated the correlations between CTGF expression and diabetes or obesity as well as activation of liver macrophages in patients with non-viral HCC. Recurrence-free survival was significantly poorer in the CTGF-positive patients compared with the CTGF-negative patients (p = 0.002). Multivariate analysis determined that CTGF expression (HR 2.361; 95 % CI 1.195-4.665; p = 0.013) and vascular invasion (HR 2.367; 95 % CI 1.270-4.410; p = 0.007) were independent prognostic factors for recurrence of non-viral HCC.

CONCLUSIONS

Our data suggest that CTGF could be involved in oncogenic pathways promoting non-viral HCC associated with metabolic risk factors via induction of liver inflammation and is expected to be a novel HCC risk biomarker and potential therapeutic target.

Simple high-performance liquid chromatography method for formaldehyde determination in human tissue through derivatization with 2,4-dinitrophenylhydrazine

A simple high-performance liquid chromatography method has been developed for the determination of formaldehyde in human tissue. FA Formaldehyde was derivatized with 2,4-dinitrophenylhydrazine. It was extracted from human tissue with ethyl acetate by liquid-liquid extraction and analyzed by high-performance liquid chromatography. The calibration curve was linear in the concentration range of 5.0-200 μg/mL. Intra- and interday precision values for formaldehyde in tissue were <6.9%, and accuracy (relative error) was better than 6.5%. The extraction recoveries of formaldehyde from human tissue were between 88 and 98%. The limits of detection and quantification of formaldehyde were 1.5 and 5.0 μg/mL, respectively. Also, this assay was applied to liver samples taken from a biopsy material.

Analysis of long-term follow-up and examination of pathological liver tissue in chronic hepatitis E

Hepatitis E is chronic in immunocompromised patients with HIV infection, organ transplant, or radiation and chemotherapy. General cases are not chronic. Fifty-five cases were collected and followed up for 4-14 years. It was found that chronic hepatitis E is more common in males, but a high degree of inflammatory activity and fibrosis was not evident. After 4-14 years of follow-up observation, cirrhosis or liver cancer did not appear. This is significantly different from the hepatitis B and C viruses. We speculated that the chronic mechanism in the general patients with hepatitis E might be different from that of immunocompromised cases.

Alteration of liver glycopatterns during cirrhosis and tumor progression induced by HBV

The incidence of hepatocellular carcinoma (HCC) is closely correlated with hepatitis B virus (HBV)-induced liver cirrhosis. Structural changes in the glycans of serum and tissue proteins are reliable indicators of liver damage. However, little is known about the alteration of liver glycopatterns during cirrhosis and tumor progression induced by HBV infection. This study compared the differential expression of liver glycopatterns in 7 sets of normal pericarcinomatous tissues (PCTs), cirrhotic, and tumor tissues from patients with liver cirrhosis and HCC induced by HBV using lectin microarrays. Fluorescence-based lectin histochemistry and lectin blotting were further utilized to validate and assess the expression and distribution of certain glycans in 9 sets of corresponding liver tissue sections. Eight lectins (e.g., Jacalin and AAL) revealed significant difference in cirrhotic tissues versus PCTs. Eleven lectins (e.g., EEL and SJA) showed significant alteration during cirrhotic and tumor progression. The expression of Galα1-3(Fucα1-2)Gal (EEL) and fucosyltransferase 1 was mainly increasing in the cytoplasm of hepatocytes during PCTs-cirrhotic-tumor tissues progression, while the expression of T antigen (ACA and PNA) was decreased sharply in cytoplasm of tumor hepatocytes. Understanding the precision alteration of liver glycopatterns related to the development of hepatitis, cirrhosis, and tumor induced by HBV infection may help elucidate the molecular mechanisms underlying the progression of chronic liver diseases and develop new antineoplastic therapeutic strategies.

Relationship of serum liver function parameters and hepatitis B virus markers with liver histopathology in patients with chronic hepatitis B

AIM: To investigate the relationship of liver function parameters and hepatitis B virus (HBV) markers with liver histopathology in chronic hepatitis B patients.

METHODS: Ninety patients with chronic hepatitis B treated at Sanya Chronic Disease Prevention and Control Center from January 2013 to December 2014 were included. The patients underwent liver biopsy, and their venous blood was collected to measure liver function parameters and HBV markers. The relationship between these parameters/markers and liver fibrosis stage/inflammation grade was analyzed.

RESULTS: The differences in alanine aminotransferase (ALT), glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), cholinesterase (CHE), albumin (Alb)/globulin (GLb), prealbumin (PA), and total bilirubin (TBIL) between the mild inflammation group and the severe inflammation group were statistically significant (P < 0.05). The differences in ALT, GGT, ALP, CHE, Alb/GLb, PA, and TBIL were also statistically significant between the mild and severe fibrosis groups (P < 0.05).

CONCLUSION: Measurement of liver function indexes in chronic hepatitis B patients can directly determine the variation of liver pathology. HBV DNA load and hepatitis B surface antigen (HBsAg) quantitation have no correlation with liver histological changes.

Differential expression of six genes and correlation with fatness traits in a unique broiler population

Previous results from genome wide association studies (GWASs) in chickens divergently selected for abdominal fat content of Northeast Agricultural University (NEAUHLF) showed that many single nucleotide polymorphism (SNP) variants were associated with abdominal fat content. Of them, six top significant SNPs at the genome level were located within SRD5A3, SGCZ, DLC1, GBE1, GALNT9 and DNAJB6 genes. Here, expression levels of these six candidate genes were investigated in abdominal fat and liver tissue between fat and lean broilers from the 14th generation population of NEAUHLF. The results showed that expression levels of SRD5A3, SGCZ and DNAJB6 in the abdominal fat and SRD5A3, DLC1, GALNT9, DNAJB6 and GBE1 in the liver tissue differed significantly between the fat and lean birds, and were correlated with abdominal fat traits. The findings will provide important references for further function investigation of the six candidate genes involved in abdominal fat deposition in chickens.

Size and age-concentration relationships for perfluoroalkyl substances in stingray livers from eastern Australia

While the literature has reported a widespread occurrence of perfluoroalkyl substances (PFASs) in marine biota, very limited studies have been dedicated to the southern hemisphere. Hepatic concentrations of nine PFAAs were analysed in 49 stranded stingrays from eastern Australia using liquid chromatograph coupled with tandem mass spectrometry and relationships with biological parameters (i.e. body size, age and sex) were investigated. Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) were the predominant compounds quantified, with hepatic concentrations varying from 2 to 117 and from 0.2 to 19 ng·g(-1) w.w., respectively. A negative correlation between the concentration of PFASs in the livers of 32 blue-spotted stingrays and the body size/age was found. This relationship was independent of the animal's sex. We postulate that the dependence on body size is related to differing uptake kinetics of the chemicals, after the sting rays were exposed to an increased level of the contaminants in their environment. Such a pollution event could be related to a severe flood event that occurred at this location a few months before the samples' collection. Our results indicate that the influence of the body size/age should be taken into account when estimating bioaccumulation parameters from environmental measurements or exposure levels of biota to PFASs.

Presence of disease specific autoantibodies against liver sinusoidal cells in primary biliary cirrhosis

AIM: To investigate the presence of autoantibodies directed against liver sinusoidal cells in primary biliary cirrhosis (PBC).

METHODS: Liver biopsies from 21 PBC patients were studied and compared with 12 liver biopsies from disease controls [3 patients with hepatitis B (HBV) virus, 3 patients with hepatitis C virus (HCV), 3 patients with non-alcoholic steatohepatitis and 3 patients with acute alcoholic hepatitis (AAH)]. As healthy controls, we used tissue specimens adjacent to metastatic liver adenocarcinoma. Normal serum was taken from staff members of the unit. The determination of the cell type targeted by autoantibodies present in the patients sera was performed by indirect immunofluorescence (IIF) analysis using paraffin-embedded liver sections as a substrate. Sera from homologous or heterologous PBC patients or sera from the disease control group were used as primary antibodies. The presence of autoantibodies was identified using confocal microscopy.

RESULTS: In total, 18/21 (85.7%) PBC patients exhibited positive staining in the sinusoidal cells, 10/21 (47.6%) in lymphocytes, 8/21 (38%) in cholangiocytes and 7/21 (33.3%) in hepatocytes, when homologous serum and fluorescein isothiocyanate-conjugated immunoglobulin type G (IgG) secondary antibody were used. PBC sections incubated with heterologous PBC serum showed reduced staining (20% for sinusoidal cells, 20% for lymphocytes, 20% for cholangiocytes and 13.3% for hepatocytes). When IgM immunoglobulin, instead of IgG, was used as secondary antibody, positive staining was observed in 75% of lymphocytes, 62.5% of cholangiocytes, 37.5% of hepatocytes and 50% of the sinusoidal cells with a much stronger staining intensity. No staining was observed when either normal or PBC sera were used as a primary antibody on liver sections from the disease control group. When PBC sera were incubated with healthy control sections, weak positive staining of cholangiocytes was observed in 3/21 (14.3%) PBC serum samples. Steatohepatitis serum on PBC sections gave a positive staining of some hepatocytes and lymphocytes but no staining on viral hepatitis sections. Incubation with HBV sera stained some hepatocytes, cholangiocytes and intra-sinusoidal or portal lymphocytes of PBC, HBV and AAH patients but not HCV patients.

CONCLUSION: In this study, for the first time in diseased liver tissue, we have demonstrated that a large proportion of PBC patients have disease specific autoantibodies against liver sinusoidal cells.

Biophysical evaluation of physiological effects of gilthead sea bream (Sparus aurata) farming using FTIR spectroscopy

Sparus aurata is one of the two most important cultured fish species in the Mediterranean region. The present work investigates the effects of culturing in S. aurata liver tissue at the molecular level using Fourier Transform Infrared (FTIR) spectroscopy. FTIR spectroscopy revealed dramatic differences between the wild and aquacultured fish liver cells, which mainly indicated that the level of glycogen increased in the aquacultured samples and the protein/lipid ratio decreased by 42.29% indicating that triglycerides and cholesterol esters increased and the protein content decreased in the aquacultured samples. The 15.99% increase in the level of unsaturation indicated elevated lipid peroxidation. Structural/organisational changes in the nucleic acids along with increased transcriptional status of the liver tissue cells were observed in the cultured fish tissue. All these results indicated that culturing induces significant changes in fish physiology. In addition FTIR spectroscopy is a promising method to monitor the physiological changes in fish physiology.

Effects of cocktail therapy on TGF-β1, COL I and COL III expression in liver fibrosis in rats

AIM: To investigate the effects of cocktail therapy on the expression of transforming growth factor-β1 (TGF-β1), collagen I (COL I) and collagen III (COL III) in carbon tetrachloride-induced liver fibrosis in rats.

METHODS: Hepatic fibrosis was induced in rats with carbon tetrachloride. Wistar rats were divided into 7 groups: normal group, model group, colchicine group, taurine group, epigallocatechin gallate (EGCG) group, genistein group and cocktail therapy group. The rats were sacrificed at week 10 after treatment. The deposition of collagen in liver tissue was observed by HE staining. The expression of TGF-β1, COL I and COL III in hepatic tissue was detected by immunohistochemistry.

RESULTS: A significant reduction in collagen deposition and disorganization was noted in the cocktail therapy group when compared with the model group. The expression levels of TGF-β1, COL I and COL III in the cocktail therapy group, genistein group, EGCG group and taurine group, compared with the model group, markedly decreased (TGF-β1: 2.57 ± 0.23, 4.21 ± 0.35, 4.93 ± 0.21 and 4.81 ± 0.16 vs 12.11 ± 0.62, all P < 0.05; COL I: 2.69 ± 0.10, 4.88 ± 0.42, 5.04 ± 0.31 and 4.79 ± 0.29 vs 13.06 ± 0.24, all P < 0.05; COL III: 3.17 ± 0.42, 5.73 ± 0.23, 5.51 ± 0.25 and 5.24 ± 0.18 vs 15.15 ± 0.43, all P < 0.05). Cocktail therapy had a more significant inhibitory effect on the expression of these proteins than other agents tested (all P < 0.05).

CONCLUSION: Cocktail therapy has an obvious protective effect against liver fibrosis in rats possibly by remarkably inhibiting TGF-β1, COL I and COL III expression in liver tissue.

Estimating zero-strain states of very soft tissue under gravity loading using digital image correlation

This paper presents several experimental techniques and concepts in the process of measuring mechanical properties of very soft tissue in an ex vivo tensile test. Gravitational body force on very soft tissue causes pre-compression and results in a non-uniform initial deformation. The global digital image correlation technique is used to measure the full-field deformation behavior of liver tissue in uniaxial tension testing. A maximum stretching band is observed in the incremental strain field when a region of tissue passes from compression and enters a state of tension. A new method for estimating the zero-strain state is proposed: the zero strain position is close to, but ahead of the position of the maximum stretching band, or in other words, the tangent of a nominal stress-stretch curve reaches minimum at lambda greater or similar 1. The approach, to identify zero strain by using maximum incremental strain, can be implemented in other types of image-based soft tissue analysis. The experimental results of 10 samples from seven porcine livers are presented and material parameters for the Ogden model fit are obtained. The finite element simulation based on the fitted model confirms the effect of gravity on the deformation of very soft tissue and validates our approach.

Screening of genes associated with human hepatic fibrosis using cDNA microarray

AIM: To screen the genes associated with human hepatic fibrosis and explore the mechanism of hepatic fibrosis.

METHODS: Total mRNA was obtained from human hepatic fibrosis tissues and normal liver tissues respectively to prepare probe. After hybridization and cleaning, computer scan technique was used to analyze the gene expression maps of liver fibrosis tissues and normal liver tissue. Real-time fluorescence quantitative polymerase chain reaction (FQ-PCR) was adopted to verify the expression changes of some differential genes.

RESULTS: Sixty-eight differential genes were screened out, of which 35 were up-regulated and 33 were down-regulated. These genes were categorized according to their functions as cell signal transmission-regulating genes, DNA impairment and repair genes, translation-regulating factors, metabolism-related genes and function-unknown genes. As compared with that in normal liver tissues, C/EBPβ mRNA expression was down-regulated (22.02 ± 4.82 vs 59.13 ± 8.21, P < 0.01), while MMP-14 mRNA expression was up-regulated (257.33 ± 26.58 vs 21.65 ± 4.37, P < 0.01). This conformed to the results of cDNA microarray.

CONCLUSION: Multiple genes are involved in the formation of hepatic fibrosis and there is a significant difference in gene expression between normal and fibrotic liver tissues.