Animal models of liver diseases and their application in experimental surgery

Both acute and chronic liver diseases are frequent and potentially lethal conditions. Development of new therapeutic strategies and drugs depends on understanding of liver injury pathogenesis and progression, which can be studied on suitable animal models. Due to the complexity of liver injury, the understanding of underlying mechanisms of liver diseases and their treatment has been limited by the lack of satisfactory animal models. SO far, a wide variety of animals has been used to mimic human liver disease, however, none of the models include all its clinical aspects seen in humans. Rodents, namely rats and mice, represent the largest group of liver disease models despite their limited resemblance to human. On the other hand, large animal models like pigs, previously used mostly in acute liver failure modeling, are now playing an important role in studying various acute and chronic liver diseases. Although significant progress has been made, the research in hepatology should continue to establish animal models anatomically and physiologically as close to human as possible to allow for translation of the experimental results to human medicine. This review presents various approaches to the study of acute and chronic liver diseases in animal models, with special emphasis on large animal models and their role in experimental surgery.

Beneficial effects of mesenchymal stem cells on adult porcine cardiomyocytes in non-contact co-culture

Mesenchymal stem cells (MSCs) have been reported to improve survival of cardiomyocytes (CMCs) and overall regeneration of cardiac tissue. Despite promising preclinical results, interactions of MSCs and CMCs, both direct and indirect, remain unclear. In this study, porcine bone marrow MSCs and freshly isolated porcine primary adult CMCs were used for non-contact co-culture experiments. Morphology, viability and functional parameters of CMCs were measured over time and compared between CMCs cultured alone and CMCs co-cultured with MSCs. In non-contact co-culture, MSCs improved survival of CMCs. CMCs co-cultured with MSCs maintained CMCs morphology and viability in significantly higher percentage than CMCs cultured alone. In viable CMCs, mitochondrial respiration was preserved in both CMCs cultured alone and in CMCs co-cultured with MSCs. Comparison of cellular contractility and calcium handling, measured in single CMCs, revealed no significant differences between viable CMCs from co-culture and CMCs cultured alone. In conclusion, non-contact co-culture of porcine MSCs and CMCs improved survival of CMCs with a sufficient preservation of functional and mitochondrial parameters.

Distribution of Connective Tissue in the Male and Female Porcine Liver: Histological Mapping and Recommendations for Sampling

The pig is a large animal model that is often used in experimental medicine. The aim of this study was to assess, in normal pig livers, sexual dimorphism in the normal fraction of hepatic interlobular and intralobular connective tissue (CT) in six hepatic lobes and in three macroscopical regions of interest (ROIs) with different positions relative to the liver vasculature. Using stereological point grids, the fractions of CT were quantified in histological sections stained with aniline blue and nuclear fast red. Samples (415 tissue blocks) were collected from healthy piglets, representing paracaval, paraportal and peripheral ROIs. There was considerable variability in the CT fraction at all sampling levels. In males the mean fraction of interlobular CT was 4.7 ± 2.4% (mean ± SD) and ranged from 0% to 11.4%. In females the mean fraction of the interlobular CT was 3.6 ± 2.2% and ranged from 0% to 12.3%. The mean fraction of intralobular (perisinusoidal summed with pericentral) CT was <0.2% in both sexes. The interlobular CT represented >99.8% of the total hepatic CT and the fractions were highly correlated (Spearman r = 0.998, P <0.05). The smallest CT fraction was observed in the left medial lobe and in the paracaval ROI and the largest CT fraction was detected in the quadrate lobe and in the peripheral ROI. For planning experiments involving the histological quantification of liver fibrosis and requiring comparison between the liver lobes, these data facilitate the power analysis for sample size needed to detect the expected relative increase or decrease in the fraction of CT.

Relationship between follicular volume and oocyte competence, blastocyst development and live-birth rate: optimal follicle size for oocyte retrieval

OBJECTIVE

To analyze oocyte competence in gonadotropin-releasing hormone agonist (GnRHa) stimulation cycles with regard to maturity, fertilization and blastocyst rate, as well as clinical outcome (pregnancy and live-birth rate), in relation to follicular volume, measured by three-dimensional transvaginal sonography (3D-TVS), and follicular fluid composition.

METHODS

This was a prospective single-center study conducted between June 2012 and June 2014, including 118 ovum pick-ups with subsequent embryo transfer. Ovarian stimulation was performed using the GnRHa long protocol. Of 1493 follicles aspirated individually, follicular volume was evaluated successfully in 1236 using automated 3D-TVS during oocyte retrieval. Oocyte maturity and blastocyst development were tracked according to follicular volume. Intrafollicular concentrations of estradiol, testosterone, progesterone, luteinizing hormone, follicle-stimulating hormone and granulocyte-colony stimulating factor were quantified by immunoassay. Clinical outcome, in terms of implantation rate, (clinical) pregnancy rate, miscarriage and live-birth rate (LBR), was evaluated.

RESULTS

Follicles were categorized, according to their volume, into three arbitrary groups, which included 196 small (8-12 mm/0.3-0.9 mL), 772 medium (13-23 mm/1-6 mL) and 268 large (≥ 24 mm/> 6 mL) follicles. Although oocyte recovery rate was significantly lower in small follicles compared with medium and large ones (63.8% vs 76.6% and 81.3%, respectively; P < 0.001), similar fertilization rates (85.1% vs 75.3% and 81.4%, respectively) and blastocyst rates (40.5% vs 40.6% and 37.2%, respectively) per mature metaphase II oocyte were observed. A trend towards higher LBR after transfer of blastocysts derived from small (< 1 mL) follicles compared with medium (1-6 mL) or large (> 6 mL) follicles (54.5% vs 42.0%, and 41.7%, respectively) was observed. No predictive value of follicular fluid biomarkers was identified.

CONCLUSIONS

Our data indicate that the optimal follicular volume for a high yield of good quality blastocysts with good potential to lead to a live birth is 13-23 mm/1-6 mL. However, oocytes derived from small follicles (8-12 mm/0.3-0.9 mL) still have the capacity for normal development and subsequent delivery of healthy children, suggesting that aspiration of these follicles should be encouraged as this would increase the total number of blastocysts retrieved per stimulation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

[Epithelial-mesenchymal Transition in Tumor Tissue and Its Role for Metastatic Spread of Cancer]

BACKGROUND

Metastasis, recurrence, and resistance to chemotherapy are leading causes of the majority of cancer-related mortality worldwide. The process of metastasis can be artificially divided into a series of sequential, highly organized, and organ-specific steps. The underlying mechanisms are still poorly understood, but are believed to be mediated by epithelial-mesenchymal transition (EMT). First described in embryogenesis, EMT is a cellular reprogramming process in which epithelial cells acquire a mesenchymal phenotype. During this transformation, epithelial cells lose their shape, epithelial markers, and ability to grow in colonies. They acquire a spindle-shaped morphology and exhibit more motile and invasive behavior. These phenotypic changes are associated with modifications in different interconnected protein and gene families, such as transcription factors, cadherins, catenins, matrix metalloproteases, and growth receptors. EMT has been observed in many cancers, such as breast, ovarian, colon, and esophageal cancers, and is associated with poor prognosis and metastasis. Also, resistance to cytotoxic treatments is associated with reactivation of embryonic programs. Understanding this process is necessary to provide a better understanding of cancer progression and could lead to the development of new therapeutic or prognostic strategies for the treatment of cancer.

CONCLUSION

This article summarizes the known molecular pathways involved in EMT in cancer.Key words: epithelial-mesenchymal transition - carcinoma - metastasisThe authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study.The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 24. 6. 2016Accepted: 14. 11. 2016.

Circulating Tumor Cells: Fluid Surrogates of Solid Tumors

Evaluation of circulating tumor cells (CTCs) has demonstrated clinical validity as a prognostic tool based on enumeration, but since the introduction of this tool to the clinic in 2004, further clinical utility and widespread adoption have been limited. However, immense efforts have been undertaken to further the understanding of the mechanisms behind the biology and kinetics of these rare cells, and progress continues toward better applicability in the clinic. This review describes recent advances within the field, with a particular focus on understanding the biological significance of CTCs, and summarizes emerging methods for identifying, isolating, and interrogating the cells that may provide technical advantages allowing for the discovery of more specific clinical applications. Included is an atlas of high-definition images of CTCs from various cancer types, including uncommon CTCs captured only by broadly inclusive nonenrichment techniques.

Collagen/hydroxyapatite scaffold enriched with polycaprolactone nanofibers, thrombocyte-rich solution and mesenchymal stem cells promotes regeneration in large bone defect in vivo

A three-dimensional scaffold of type I collagen and hydroxyapatite enriched with polycaprolactone nanofibers (Coll/HA/PCL), autologous mesenchymal stem cells (MSCs) in osteogenic media, and thrombocyte-rich solution (TRS) was an optimal implant for bone regeneration in vivo in white rabbits. Nanofibers optimized the viscoelastic properties of the Coll/HA scaffold for bone regeneration. MSCs and TRS in the composite scaffold improved bone regeneration. Three types of Coll/HA/PCL scaffold were prepared: an MSC-enriched scaffold, a TRS-enriched scaffold, and a scaffold enriched with both MSCs and TRS. These scaffolds were implanted into femoral condyle defects 6 mm in diameter and 10-mm deep. Untreated defects were used as a control. Macroscopic and histological analyses of the regenerated tissue from all groups were performed 12 weeks after implantation. The highest volume and most uniform distribution of newly formed bone occurred in defects treated with scaffolds enriched with both MSCs and TRS compared with that in defects treated with scaffolds enriched by either component alone. The modulus of elasticity in compressive testing was significantly higher in the Coll/HA/PCL scaffold than those without nanofibers. The composite Coll scaffold functionalized with PCL nanofibers and enriched with MSCs and TRS appears to be a novel treatment for bone defects.

[Sperm mitochondrial function in men with normozoospermia and asthenozoospermia]

OBJECTIVE

One of causes of male infertility is reduced sperm motility. It turns out that the reduced efficiency of the mitochondrial respiratory activity may play a role in the development of this disorder. The aim of our study was to comprehensively determine mitochondrial respiratory activity of sperm with normal and reduced motility.

DESIGN

Prospective study.

SETTING

Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University in Prague; Department of Physiology, Faculty of Medicine in Pilsen, Charles University in Prague; Institute of Reproductive Medicine and Endocrinology, IVF Centers Prof. Zech, Plzeň.

METHODS

Ejaculates of 14 men were obtained from IVF Center Prof. Zech, Pilsen. According to the World Health Organization classification, samples were divided into normozoospermatic (n = 7) and asthenozoospermatic(n = 7) groups. Respiratory activity of sperm was measured on two-chamber oxygraph Oroboros.

RESULTS

In asthenozoospermatic samples, significantly reduced activity of complex I (p = 0.007) and increased respiration after application of ATP-synthase inhibitor oligomycin (showing increased uncoupled oxidation and phosphorylation, p = 0.046) were found. Inhibition of complex I by rotenone showed that complex I contribution to the total capacity of oxidative phosphorylation of healthy sperm was relatively lower than it is typical for somatic cells.

CONCLUSION

In our study, we measured mitochondrial respiratory activity of human sperm, permeabilized by digitonin, by high-resolution oxygraphy, which allows the determination of oxygen consumption from the smallest possible number of germ cells. The study results confirm reduced activity of complex I in asthenozoospermatics and suggest that increased leakage of protons from the mitochondrial matrix, which leads to reduced efficiency of phosphorylating process, could participate in the reduced sperm motility. Better characterization of male germ cells, either completely healthy or with affected motility, will help us to understand better the physiological process of fertilization and also to choose the most viable sperm for infertility treatment by methods of assisted reproduction.

[Czech registry of complications in gynecological laparoscopy - the on-line data collection]

OBJECTIVE

To survey the performance of laparoscopically assisted vaginal hysterectomy (LAVH) and other gynecologic laparoscopic operations performed in the Czech Republic.

DESIGN

Retrospective study (Canadian Task Force classification II-3).

SETTING

Departments of gynecology in the Czech Republic.

METHODS

Two paper questionnaires were sent to 120 clinics performing laparoscopic gynecologic operations in the past, the data have been collected via web application since 2013.

RESULTS

Process of transition from paper questionnaires to electronic forms was realized without complications. Number of clinics that responded was the highest during 5 last years. Number of reported gynecologic laparoscopic operations in 2013 was the second highest since the establishment of the Registry.

CONCLUSION

Unchanged trend of decrease in number of abdominal hysterectomy. Latest data shows the possibility of vaginal hysterectomy renaissance.

[Effect of overweight on the outcome of assisted reproductive technology in infertile women]

OBJECTIVE

Obesity and overweight negatively affect the ability of women to conceive naturally, contributes to the increased incidence of obstetric complications during pregnancy and affect the outcome of assisted reproduction techniques (ART). The aim of our study was to compare the results of treatment of infertilityin a group of infertile women undergoing ART, depending on the values of BMI and changes in levels of selected hormones and markers of oxidative stress in follicular fluid.

DESIGN

Retrospective comparative study.

SETTING

Faculty of Medicine in Pilsen, Charles University in Prague; Institute of Reproductive Medicine and Endocrinology, IVF Centers - Prof. Zech, Plzeň.

METHODS

The studied group consisted of 44 women (mean age of 31.9 years, SD = 4.35) treated for infertility at the Institute of Reproductive Medicine and Endocrinology - IVF Centers Prof. Zech. Women were divided into 2 groups according to BMI (37 women had normal BMI, 7 women were overweight). Prolactin, free T3 and T4 hormone, homocysteine, malondialdehyde, glutathione peroxidase, total antioxidant capacity and total protein were analyzed in the follicular fluid both groups. Only blood free samples were studied after pooling of all FF samples of each patient.

RESULTS

We observed significantly lower levels of glutathion peroxidase in the group of overweight women(p = 0.0044). The pregnancy success rate with women with normal BMI and overweight women did not differ significantly from each other (p = 0.4430).

CONCLUSION

Our study did not confirm the negative effect of obesity on the results of treatment of infertility, specifical-ly pregnancy rate in a group of infertile women undergoing treatment with assisted reproduction techniques.

[Analysis of point mutations in interleukin-11 gene in the population of infertile patients and fertile control women]

OBJECTIVE

The interleukin-11 (IL-11) is one of the most important signaling factors in the process of decidua-lization and embryo-maternal cross talk during the embryo implantation. We investigated the prevalence of the IL-11 gene point variants in the population of infertile women and fertile control subjects.

DESIGN

A cohort study.

SETTING

Department of Obstetrics and Gynecology, Faculty of Medicine and University Hospital of Charles University, Pilsen.

SUBJECTS AND METHODS

The population to screen consisted of 354 infertile women. The control population was comprised of 195 healthy fertile subjects. For the mutational analysis, the temperature gradient gel electrophoresis (TGGE) and direct sequencing had been used. The groups of fertile controls and infertile patients were compared for statistically significant difference using the Fisher´s 2 by 2 Exact test.

RESULTS

Thirteen potentially functional IL-11 gene variants, the G to A transversions at the position 3651 (G3651A) leading to the arginin to histidin exchange on the position 113 (R113H) were detected in the group of infertile women. No mutations were identified in the control group, which means that the frequency of functionally relevant mutations of the IL-11 gene in infertile women is significantly enhanced in comparison with controls (p = 0.01, Fisher´s 2 by 2 Exact test).

CONCLUSION

The results prove the presence of the potentially functionally relevant IL-11 gene variants in the population of infertile women. The presence of variants does not have to lead directly to decrease fertility but may contribute to the dysbalance of cytokine milieu which is needed for the decidualization as well as subsequent embryo implantation. Even thought IL-11 gene variants occur infrequently, their impact on molecular events during early phases of pregnancy should be further elucidated.

[Comparison of selective oxidative stress parameters in the follicular fluid of infertile women and healthy fertile oocyte donors]

OBJECTIVE

Follicular fluid (FF) affects oocyte development and disruption of its homeostasis has a crucial effect on egg developmental potential. The aim of this study was to compare the levels of selected oxidative stress markers in the FF of women with impaired fertility and healthy fertile oocytes donors.

DESIGN

A retrospective comparative study.

SETTING

Faculty of Medicine in Pilsen, Charles University in Prague; Institute of Reproductive Medicine and Endocrinology, IVF Center Prof. Zech, Pilsen.

METHODS

Levels of homocysteine (Hcy), malondialdehyde (MDA), glutathione peroxidase (GPx), total antioxidant capacity (AOK) and total protein (CB) were analyzed in the FF. We have analysed FF of 146 women - 74 infertile patients (mean age 31 years, SD = 4.65) and 72 healthy fertile oocyte donors (mean age 26 years, SD = 4.44). Only blood free samples were studied after pooling of all FF samples each patient.

RESULTS

The study showed a statistically significantly higher Hcy levels (p < 0.0001) in the FF of healthy fertile women compared with impaired fertility group both - comparing the two groups regardless the age and in groups of the same age range (for the age group between 20 to 29 years isp = 0.0002, for the age group between 30 to 39 years is p < 0.0001). When divided into above age ranges we found statistically significantly higher levels of MDA in the control group aged 20 to 29 years compared to same age infertile patients (p = 0.0374) and statistically significantly higher AOK in infertile women between 30 to 39 years of age compared to same age control group (p = 0.0458).

CONCLUSION

The presence or on the contrary the absence of prooxidant parameters in the FF has an important role in the ability of conception and subsequent embryo development.

[Comparison of prolactin, free T3 and free T4 levels in the follicular fluid of infertile women and healthy fertile oocyte donors]

OBJECTIVE

Follicular fluid (FF) provides an important microenvironment for the development of oocytes. The biochemical composition of the FF plays critical role in the oocyte competence. The aim of our study was to compare the levels of selected hormones in FF of infertile women and healthy fertile oocyte donors.

DESIGN

Retrospective comparative study.

SETTING

Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University in Prague; Department of Gynecology and Obstetrics, Charles University and University Hospital in Pilsen; Institute of Reproductive Medicine and Endocrinology, IVF Centers Prof. Zech, Plzeň.

METHODS

Levels of prolactin, free T3 and free T4 hormones in the FF of 146 women were analyzed. We have analysed FF of 74 infertile patients (mean age 31 years, SD = 4.65) and 72 healthy fertile oocyte donors (mean age 26 years, SD = 4.44). Only blood free samples were studied after pooling of all FF samples each patient. Levels of hormones were determined using ECLIA method (Electro-Chemi-Luminiscent Immunoassay) on the Cobas e411.

RESULTS

RESULTS showed statistically significantly higher levels of prolactin (p=0.0006) and free T4 hormone (p=0.0246) in FF of infertile women in comparison to the group of healthy fertile oocyte donors.

CONCLUSION

Our study confirms the presence of prolactin and thyroid hormones in FF and it can be suggested that they play a key role in the regulation of reproductive processes. The study of FF from donors and their detailed comparison with infertile patients with various gynaecological causes of infertility has great value for better understanding of regulatory mechanisms of fertility.

Comparison of P19-derived neuroprogenitor and naive cell survival after intracerebellar application into B6CBA mice

Mouse embryonic carcinoma cells (P19 line) were studied for both their survival and developmental potential in the intact cerebellum of B6CBA mice. The P19 cells were cultured and labelled with green fluorescent protein using transfection. Cells were used for transplantation either in the undifferentiated stage or after 3 days of neurodifferentiation induced by retinoic acid. The intracerebellar application was performed in 43 mice: group A (N = 21) received neuroprogenitors and group B (N = 22) received undifferentiated cells. The morphology of transplanted cells within the context of the surrounding cerebellar tissue was evaluated after 3 weeks. Naive P19 cells engrafted and survived in the cerebellum of 7 of the 22 adult mice (survival rate 31.8 %). Neuroprogenitors survived in 13 of the 21 mice (survival rate was 61.9 %). Since the cut-off is P < 0.05, the difference is not statistically significant (P = 0.069). An expansive appearance of the graft was significantly more frequent (P = 0.0047) in naive P19 cells than in neuroprogenitors. In mice in which the grafts did not survive, no marks of grafted cells or only fluorescing detritus were found. In conclusion, this is the first study to track the fate and morphology of embryonic carcinoma cells transplanted into the cerebellum, confirming that neuroprogenitors derived from embryonic carcinoma cells can settle in the host tissue and differentiate according to the surrounding conditions. With further validation, the embryonic carcinoma cells could become a valuable model with which to study the impact of cell therapy on neurodegenerative diseases.

Characterization of P19 cells during retinoic acid induced differentiation

The aim of our study was to characterize mouse embryonal carcinoma (EC) cells P19 in different stages of retinoic acid induced neurodifferentiation by two methods, immunocytochemistry and RT qPCR. The characterization of the cells is crucial before any transplantation into any model, e.g. in our case into the mouse brain with the aim to treat a neurodegenerative disease. Specific protein markers (MAP-2, OCT-4, FORSE-1) were detected by immunocytochemistry in the cell cultures. The mRNA expression levels of PAX-6, MASH-1, Brachyury, GATA-4 and AFP were determined by RT qPCR method. HPRT was used as a housekeeping gene. The degree of differentiation can be characterized by expression of analyzed genes. The presence of OCT-4 and FORSE-1 proteins in undifferentiated pluripotent cells and the presence of dendrite specific MAP-2 in neuroprogenitors was detected. The expression levels of PAX-6 and MASH-1 increased and expression of Brachyury decreased during the neurodifferentiation process. The expression levels of GATA-4 and AFP were the highest after induction of differentiation with retinoic acid. Detailed characterization of cells before transplantation experiments can contribute to better understanding of their effect.