Search

Discusses the active role H5, a linker histone, plays in the control of chromatin activity. A transfected H5 gene in rat sarcoma cells, which do not produce H5, showed an arrest of cell proliferation. The results also show H5 may play an active part in the control of DNA replication.

Abstract: Introduction: Organ ischemia is accompanied by cell death due to apoptosis. It occurs together with necrosis, which has more unfavorable consequences due to the release of cytokines that activate the inflammatory response cascade. The aim of this study was to assess the degree of apoptosis in porcine livers preserved by simple hypothermia for 12 hours using standard solutions (University of Wisconsin [UW] and histidine-tryptophan-glutarate [HTK]), and to evaluate the effect of prolactin (PRL) addition to the HTK solution. Materials and methods: The study was performed on the livers of Great White breed pigs, after inducing 30 minutes of warm ischemia (WIT30), followed by 30 minutes of perfusion-cooling to 4°C, and 12 hours of preservation. Livers were evaluated after preservation in Ringer''s solution (control); UW (control reference fluid); HTK and HTK modified by the addition of prolactin (20 UI/L. Apoptosis was assessed in liver sections by the TdT-mediated dUTP nick-end labeling method after 12-hour preservation. We adopted a prevalence scale ranging from 0 to 3+, depending on the number of observed nuclei and apoptotic bodies (AB). Results: Preservation in Ringer''s solution yielded AB distribution at the 1+ level, with a lack of characteristic localization resulting from necrotic lesions. Analysis of the livers preserved in the UW solution showed high, 3+ level of AB presence. For the tested HTK solution, the observed ABs localization value was 3+, whereas in the PRL-modified group it was also 3+, but with a tendency to move from zone II to cluster III, which is important for liver metabolic functions. Conclusions: PRL improved the preservation properties of HTK for porcine livers by maintaining a high apoptosis level. It may stabilize cell membranes thus reducing the oncotic necrosis, promoting increased apoptosis during simple hypothermia. [Copyright &y& Elsevier]

The developing organism lacks many of the cytochrome P450 isoforms detected in the adult, or they are expressed at very low levels. It remains controversial whether P450 gene regulatory mechanisms are present prenatally. As a result, the catalytic function of P450s in fetal tissues has been questioned. The aim of our study was to evaluate CYP: 1A1, 1A2, 2B1/2, 2E1, 3A1 and 3A2 expression in livers of 18- and 20-days-old fetuses, and newborns from untreated and β-naphthoflavone-, phenobarbital-, dexamethasone- or ethanol-treated Sprague-Dawley rats. CYP expressions were evaluated at both transcriptional (RT-PCR) and protein (Western blotting) levels. CYP mRNA expressions were detected on day 18 of gestation. CYP: 1A1, 2B1/2 and 3A1 proteins were found on day 18; CYP2E1 protein -- on day 20; 1A2 and 3A2 protein -- in newborn livers. Studied P450s demonstrated a very low expression in animal tissues before and just after birth but, in most cases, they were inducible. It is concluded that the inductory mechanisms of CYP: 1A1, 2B1/2, 3A1/2 and 2E1 but not CYP1A2, are functional in fetal liver at transcriptional or translational levels. The effects of metabolic activation of CYP1A2 substrates may be reduced in fetuses. [ABSTRACT FROM AUTHOR]

Abstract The aim of this paper was to describe the differences in vascular endothelial growth factor (VEGF) concentration in porcine kidneys removed from living donors (group I), donors after prior induction of brain death by brain herniation (group II), and donors after cardiopulmonary arrest (group III). The groups consisted of 6 animals which underwent dual renal removal procedures; kidneys were rinsed, stored for 24 hours at 4°C and rinsed again. Renal specimens (4g) were collected before and after perfusion (time 0 and 1), after 12 hours (time 2), and after reperfusion (time 3). A Western blot was used to evaluate VEGF concentration in collected tissues homogenates. Additionally, the levels of VEGF, interleukin 1β, tumor necrosis factor α, and endothelial nitric oxide synthase (eNOS) were detected with enzyme-linked immunosorbent assays. Directly after the removal procedure, no significant differences in VEGF levels (IOD) were observed depending on the donor (moderate levels were observed in all groups: 1.51 in group I, 1.48 in group II, and 1.35 in group III). As a consequence of perfusion and 12 hours of storage, a stable concentration in groups I and III was observed with a gradual increase of VEGF levels in group II (1.23, 2.08, and 1.67 in the respective groups at time 1; 1.49, 2.12, and 1.63 in the respective groups at time 2). After the following 12 hours, a statistically significant (P <.05) higher level of VEGF was observed in group II (2.34) in comparison to groups I and III (1.58 and 1.81, respectively). In group I, a correlation between VEGF concentration and IL-1β was observed, while in group II there was correlation between VEGF and eNOS levels. Highlights • Directly after removal, VEGF concentration in the kidney was similar in all types of donors. • Cold ischemia increases the concentration of VEGF. • The highest VEGF levels were observed in donors after brain death. [ABSTRACT FROM AUTHOR]

Background Because of an insufficient number of human organs for transplantation, xenotransplantation may become an effective alternative. We aimed to analyze if the type of transgenesis has an influence on the hepatic caspase-3 expression, the enzyme that executes apoptosis as well as ALT, AST, and GGT activity after 24 hours of cold storage. Methods The experiment was carried out on the 24 livers of Polish White Landrace pigs carrying human α1,2-fucosyltransferase and/or α-galactosidase (GAL) genes and livers without this genetic modification (control). Livers were perfused, stored for 24 hours in solution, and subsequently re-flushed. Hepatic concentration of the caspase-3 protein and its mRNA expression were measured just after the animal was killed as well as after 30 minutes of perfusion and after 24 hours of cold storage followed by 30 minutes of reperfusion. Caspase-3 mRNA level was detected with the RT-PCR method. Protein concentration (capsase-3 active and inactive) was assessed with the Western blotting technique. Kinetic methods were applied for the analysis of the ALT, AST, and GGT activity. Results The highest increase of the ALT activity after cold storage was observed in the group with GAL transgenesis, whereas the GGT activity was highest in the unmodified livers. There was no difference in the caspase-3 expression and AST activity after cold storage as compared with the respective initial results ( P = .57 and P = .97, respectively). Conclusions It appears that transgenesis does not aggravate ischemic injury of the liver. [ABSTRACT FROM AUTHOR]

Background An insufficient number of organs for transplantation shows the need for the development of new technologies. Xenotransplantation might be the answer. Objective To determine if the type of transgenesis influences the level of CYP3A4, which takes an active part in xenobiotics metabolism in livers after 24-hour storage, depending on the kind of solution used for preservation. Materials and methods The experiment was carried out on 30 livers of Polish White Landrace divided into 5 groups depending on transgene type. The following human genes were transferred: α1,2-fucosyltransferase (groups I and II), α-galactosidase (III), combined α1,2-fucosyltransferase/α-galactosidase transgene (IV), and livers without modification (V). The livers were perfused and subsequently stored for 24 hours in Ringer's solution (group I) or Biolasol solution (II-V). Reperfusion/reflush was performed. CYP3A29 isomer concentration was analyzed in liver specimens collected twice: 30 minutes after perfusion and 30 minutes after reperfusion/reflush. Expression of mRNA CYP3A29 was marked using RT-PCR analysis and of protein CYP3A29 using Western blotting technique. Results The most significant decrease in protein CYP3A29 expression after 24-hour preservation was observed in group I (55.88% decrease), while the least significant was observed in group IV (10.44% decrease). mRNA expression evaluation was similar: the most significant decrease was observed in group I (87.8% decrease) and the least significant in group III (4.6% decrease). Conclusion α1,2-Fcosyltransferase transgene seems to influence mRNA and protein CYP3A expression in case of liver grafting and preservation for transplantation. CYP3A expression was also influenced by the kind of preservation solution used. [ABSTRACT FROM AUTHOR]

Background Transgenic animals may serve as organ donors in human organ transplantation. However, the number of the studies addressing all doubts related to this issue is currently insufficient for the clinical application of this approach. The aim of this study was to analyze the hepatic tumor necrosis factor–α (TNF-α) and interleukin-1β (IL-1β) synthesis during a 24-hour cold preservation of the transgenic pig liver, depending on the type of transgenesis. Materials and Methods The study was carried out on wild-type and transgenic pig livers with transferred human α1,2-fucosyltransferase (FUT) and/or α-galactosidase (GAL) gene (four groups; n = 6). Harvested livers were perfused for 30 minutes and stored for 24 hours in Biolasol (Biochefa) solution at 4°C with a subsequent 30-minute reperfusion (reflush). TNF-α and IL-1β concentrations were analyzed with an enzyme-linked immunosorbent assay. Perfusates were collected during the initial perfusion as well as after 24 hours of preservation and during the reperfusion. Tissue samples were harvested just after animal sacrifice, and after organ perfusion and reperfusion. Results A decrease in TNF-α concentration in homogenates was noted after both perfusion and reperfusion in all experimental groups. In contrast, there was a significant decrease in IL-1β concentration in the group with combined human FUT and GAL transgenes. Concurrently, increases in TNF-α and IL-1β concentrations were observed in the reperfusion perfusates in all groups. Conclusion This study shows that IL-1β is synthesized in the ischemic livers of the transgenic animals with both human α1,2-fucosyltransferase and α-galactosidase transgenes. Further analysis is required to determine the importance of this observation. [ABSTRACT FROM AUTHOR]

Background The aim of this study was the assessment of endothelial nitric oxide synthase (eNOS) and endothelin-1 (EDN-1) expression in porcine kidneys on the 14th and 30th days after the autotransplantation procedure. Methods The research was conducted on 12 animals that underwent a left renal transplantation procedure with further standardized rinsing and 24-hour storage in 4°C; subsequently, the kidneys were implanted in the right retroperitoneal space after right-sided nephrectomy. Removed kidneys were examined (group 0). Six randomly chosen animals (group 1) were under observation for 14 days and 6 others (group 2) for 30 days. Results After these observation periods, euthanasia was performed on the animals and 4-g samples were collected from the renal cortex and medulla. The Western blot technique was used to detect the eNOS and EDN-1 expression at the protein level. The obtained results are presented as absolute values of integrated optical density. Stable graft function was observed in all animals from the 2nd day after the procedure. eNOS in group 1 reached the mean value of 1.064 and was statistically significantly lower than in group 2 (2.085) or in the control group 0 (3.318). In the case of EDN-1 expression on 14th day after transplantation, the medium level was reported (0.248), which was similar to group 0 (0.216), whereas group 2 presented values 2 times higher (0.743). Conclusions A lowered eNOS level in the organ was observed on the 14th day after autotransplantation of a pig kidney; further enzyme normalization is associated with increased EDN-1 expression. [ABSTRACT FROM AUTHOR]

Objectives The aim of this paper was to evaluate mRNA expression of Toll-like receptors 2 (TLR2) and 4 (TLR4) and the adaptor protein myeloid differentiation primary-response protein 88 (MyD88) in pigs' kidneys 14 and 30 days after autotransplantation. Methods The research was conducted on 12 animals that underwent left renal transplantation procedure with further standardized rinsing with Biolasol solution and 24 hours' storage in 4°C; subsequently the kidneys were implanted in the right retroperitoneal space after right-side nephrectomy. Six randomly chosen animals (group I) were under observation for 14 days, the other 6 (group II) for 30 days. After these observation periods, the animals were killed and 4-g samples were collected from the renal cortex and medulla. Results Expression of mRNA in homogenates of collected samples were determined with the use of reverse-transcription polymerase chain reaction analysis. Obtained results in both groups, presented in relation to GAPDH, were compared with the use of Mann-Whitney U test. Stable graft function was observed in all animals from the 2nd day after the procedure. TLR2 in group I reached the mean value of 3.64 and was statistically significantly higher than in group II (2.19). Inverse proportion was observed in case of mRNA for TLR4: group II presented 2 times higher value than group I (0.25 vs 0.11). Similarly, significant difference was observed in MyD88 (group I, 0.067; group II, 0.45). Conclusions At 14 days after autotransplantation of a pig kidney, mRNA expression for TLR2 is dominant; later, expression increases for TLR4 and MyD88. [ABSTRACT FROM AUTHOR]

Introduction Biolasol solution (Pharmaceutical Research and Production Plant “Biochefa,” Sosnowiec, Poland) is a novel extracellular perfusion and ex vivo hypothermic kidney preservation solution. It ensures maintenance of homeostasis, reduces tissue edema, has low viscosity, and allows the graft to preserve structural and functional integrity. It minimizes ischemia-reperfusion damage. Methods Perfundates from control and transplanted kidneys flushed with Biolasol or ViaSpan solutions (Arkas, Warszawa, Poland) were analyzed. Parameters of serum and urine collected from 12 pigs after auto-transplantation were also analyzed. Renal medulla was investigated for structural alterations by analyzing hematoxylin and eosin–stained slides. The mean survival time of pigs after the auto-transplantation procedure was the measure for the novel Biolasol solution effectiveness. Results We observed a statistically significant decrease in marker enzyme levels alanine transaminase, aspartate transaminase, lactic dehydrogenase, and ions (Na and K) in pigs with grafts flushed with Biolasol. Histopathologic examination revealed that the renal cortex structure was not damaged after the use of Biolasol solution. Conclusion Biolasol solution protects kidneys against ischemia damage and does not differ significantly from the “golden standard” ViaSpan solution. [ABSTRACT FROM AUTHOR]

Objectives The aim of this paper was to describe differences between levels of endothelial nitric oxide synthase (NOS-3) and endothelin-1 (ET-1) in swine kidneys removed from living donors (group I) and after inducing brain death by brain herniation (group II) and cardiac arrest (group III). Methods Each group consisted of 3 animals who underwent dual renal removal procedure; kidneys were further rinsed according to standardized procedure with Biolasol perfusion liquid, stored for 24 hours (4°C), and rinsed again. Renal specimens of 4 g mass, including renal cortex and medulla, were collected before and after perfusion (times 0 and 1), after 12 hours (time 2), and after reperfusion (time 3). Enzyme-linked immunosorbent assay was used to describe levels of NOS-3 and ET-1 in collected tissues homogenates. Mann-Whitney U test was used to compare results in groups in relation to total protein content (ng/mg), and the correlation between the 2 substances was measured with the use of Spearman rho. Results Group I presented low and stable levels of NOS-3 in all time intervals (averages, 0.73, 0.99, 0.52, and 0.89, respectively). Level sof ET-1 were similar (0.87, 0.63, 0.69, and 0.86, respectively), and significant correlation between levels of the 2 substances was observed. Increased levels of NOS-3 (1.89 and 1.86) and ET-1 (1.38 and 1.49) were observed directly after removal in groups II and III and further maintained during organ storage. No correlation in group I was observed, and after perfusion significantly lower level of NOS-3 was observed in kidneys removed after brain death in relation to group III (1.77 vs 2.60). Conclusions The lowest and stable levels of NOS-3 and ET1 during storage were observed in kidneys removed from living donors. Levels of analyzed substances in this group showed correlation in subsequent time intervals. [ABSTRACT FROM AUTHOR]

Introduction Increasing the human lifespan contributes to a higher number of patients with end-stage organ failure, which in turn stimulates the search for alternative sources. Xenotransplantation seems to be a promising approach in this respect. Objective Analysis of changes in interleukin (IL)-6 concentration during 24-hour preservation of transgenic swine livers, depending on the kind of transgenesis and preservation solution used. Materials and methods The experiment was carried out in swine livers with transferred human genes that were divided into 5 groups. The following human genes were transferred: α1,2-fucosyltransferase (group I and II), α-galactosidase (III), combined α1,2-fucosyltransferase/α-galactosidase transgene (IV), and livers without modification (V). The livers were perfused and subsequently stored for 24 hours in Ringer's (group I) or Biolasol solutions (II–V). Reflush was then performed. IL-6 concentration was analyzed in the solution samples collected at the beginning and end of perfusion, and after 24 hours of preservation. ELISA was used to evaluate IL-6 concentration. Results In liver homogenates from group I, IL-6 concentration after 24 hours of preservation increased by 8.24% compared to the levels observed after perfusion, whereas in the other groups IL-6 concentration decreased. The most significant decrease, 49.51%, was observed in group II; the least significant in group IV, 10.72%. In case of supernatants, a statistically significant increase of AUC 0–30min level in relation to perfusion was observed in every group after 24-hour preservation and reperfusion. The highest values of AUC 0–30min were observed in group I (α1,2-fucosyltransferase, Ringer's solution). Conclusion The study indicates the hepatoprotective action of Biolasol solution. [ABSTRACT FROM AUTHOR]