Hepatocytes Of Animals Research Articles

In vivo selection of hepatocytes

The liver is a highly regenerative organ capable of significant proliferation and remodeling during homeostasis and injury responses. Experiments of nature in rare genetic diseases have illustrated that healthy hepatocytes may have a selective advantage, outcompete diseased cells and result in extensive liver repopulation. This observation has given rise to the concept of therapeutic liver repopulation by providing an engineered selective advantage to a subpopulation of beneficial hepatocytes. In vivo selection can greatly enhance the efficiency of both gene and cell transplantation therapies for hepatic diseases. In vivo hepatocyte selection has also enabled the expansion of human hepatocytes in animals, creating novel models of human liver disease and biology. Finally, recent work has shown that somatic mutations produce clonal expansion of injury resistant hepatocytes in most chronic liver diseases. In this review, we will address the role of hepatocyte selection in disease pathophysiology and therapeutic strategies.

Analysis of Curcumin on proliferation, apoptosis and differentiation of hepatocyte mice balb/C exposure to benzapyrene: A Systematic Review

Objective: To analyse Curcumin effect on proliferation, apoptosis, and hepatocyte differentiation of Balb/C Mice exposed to benzapyrene. Methodology: A literature search was carried out systematically through the PubMed, NCBI, and Google Scholar databases using keywords, “Curcumin, Proliferation, Apoptosis and Hepatocyte Differentiation of Mice Balb/C, Benzapyrene”. Based on these keywords, the articles obtained were first selected by setting several inclusion criteria. Results: A total of 550 articles were obtained for the keywords “Curcumin, Proliferation, Apoptosis and Hepatocyte Differentiation of Mice Balb/C, Benzapyrene and 28 met the inclusion criteria. Curcumin reduced the hepatocyte proliferation index in experimental animals exposed to BaP and increased the hepatocyte apoptosis index in experimental animals exposed to BaP. It reduced the N/C ratio of hepatocytes in experimental animals exposed to BaP. Conclusion: Administration of curcumin in the diet during the initiation and post-initiation periods can inhibit the increase in PCNA expression, increase apoptosis, and improve hepatocyte differentiation patterns exposed to benzopyrene and curcumin.

Protective effects of chlorogenic acid against cyclophosphamide induced liver injury in mice

ABSTRACT We investigated possible protective effects of chlorogenic acid (CGA) against cyclophosphamide (CP) induced hepatic injury in mice. We measured aminotransferase alanine transaminase (ALT) and aspartate transaminase (AST) levels in the serum. We assayed catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in hepatic tissue. We assessed expression of nuclear transcription factor 2 (Nrf2) and Kelch sample related protein-1 (keap1) proteins in hepatic tissues using immunohistochemistry. The relative mRNA expression levels of heme oxygenase-1 (HO-1), NADH quinone oxidoreductase 1 (NQO1), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined using quantitative real-time polymerase chain reaction (qRT-PCR). Hematoxylin & eosin staining was used to assess liver histopathology. We found that administration of CGA prior to induction of injury by CP decreased serum ALT, AST and MDA expressions in hepatic tissue, while CAT, SOD, GSH and GSH-Px concentrations were increased. We found that hepatocytes of animals administered CGA gradually returned to normal morphology. CGA increased the protein expression of Nrf2 in murine hepatic tissue. Administration of CGA up-regulated mRNA expression levels of HO-1, NQO1, TNF-α and IL-6 in hepatic tissue. CGA exhibited a marked protective effect on CP induced liver injury in mice.

Incorporation of exemestane into ternary nanosponge system for enhanced anti-tumor potential in breast cancer

The present investigation reports the potential of exemestane loaded cyclodextrin based nanosponges for the treatment of breast cancer. Fourier transform infrared, and nuclear magnetic resonance (NMR) spectroscopic analysis confirmed the encapsulation of ring B, C, and D of exemestane in the nanosponge cavity. In vitro studies demonstrated a 6.58-folds increase in the aqueous solubility and a 1.76-folds increase in the dissolution of exemestane in the optimized nanosponge formulation EF2. It also exhibited enhanced cytotoxicity in MCF-7 cell line. Pharmacokinetic studies revealed a 1.37-fold increase in C max and a 2.10-fold increase in oral bioavailability of EF2, as compared to its marketed product Aromasin®. Concomitantly, this nano-formulation reduced the tumor burden to 45.71% in a DMBA-induced breast cancer rat model. This EF2-treatment also improved the hematological parameters of the animals. Histopathology of breast tissue also presented reduction in characteristic cytoarchitectural features of breast tumor. In vivo toxicity studies demonstrated reduced hepatotoxicity of the nanosponge formulation when compared with Aromasin®. These results were further supported by histological studies of excised liver tissues, where the size of hepatocytes in EF2-treated animals was like the normal hepatocyte size. In conclusion, the encapsulation of exemestane in β-cyclodextrin nanosponge along-with HPMC E5 improved its aqueous solubility, bioavailability, and ultimately therapeutic efficacy for the treatment of breast cancer.

Предиктори цитолізу гепатоцитів інсулінорезистентних щурів за умов пре- та постнатального йододефіциту

Carbohydrate metabolism markers, thyroid profile indexes, transaminase activity and structural features of liver were studied, taking into account sexual dimorphism, in rats which were keeping on a high-fructose diet under conditions of adequate iodine supply and pre- and postnatal iodine deficiency. It was found that under fructose loading of animals with iodine deficiency the risk of insulin resistance (IR) development increases (HOMA-IR index in insulin-resistant male rats under conditions of pre- and postnatal iodine deficiency increases respectively by 22 and 13% compared to the data in animals that received a high-carbohydrate diet and adequate iodine supply). It is important, that in males and females with IR, the secretion of free triiodothyronine decreased by 36 and 40%, thyroid-stimulating hormone – by 28 and 34%, respectively, compared to the data of intact animals. The development of IR was accompanied by the activation of aminotransferases in blood serum (more in males). In particular, in male rats with IR under conditions of pre- and postnatal iodine deficiency, the activity of aspartate aminotransferase increased by 2.7 and 2.4 times, alanine aminotransferase – by 3.9 and 2.7 times, respectively, which led to a decrease of the de-Ritis index (more significantly against the background of prenatal iodine deficiency – by 25%) in relation to the data in animals that were on a standard diet. The activity of aminotransferases in rats with IR under conditions of iodine deprivation was higher than in animals with isolated iodine deficiency – by 11-56% and IR – by 13-47 %. In animals with IR, the presence of binucleated hepatocytes with a diffuse decrease in the number of glycogen granules in them and accumulation of glycoproteins in the wall of liver vessels were found. The foci of fatty dystrophy and pronounced zonal character of dystrophic processes in hepatocytes were identified in females, diffuse dystrophy prevailed in males. In the cytoplasm of hepatocytes of animals with IR under conditions of prenatal iodine deficiency, the lightening and the granularity, single granules of glycogen were observed. Under these conditions, the average perimeter (by 74%) and area (by three times) of hepatocytes, the average area of nucleus (by 3.1 times), the average perimeter (by 50%) and area (by 66%) of the nucleolus were increased compared to the control values. The structural changes were consistent with an increase of the transaminase activity. Thus, fructose loading and the development of IR acts as a trigger for cytolysis of hepatocytes, which increases under conditions of iodine deficiency, especially prenatal.

CARBOHYDRATES METABOLISM IN THE BLOOD OF RATS WITH IMPAIRED GLUCOSE TOLERANCE UNDER LONG TERM MELATONIN INJECTIONS.

The aim: To determine the influence of melatonin on the glucose level and content of malondialdehyde, activities of pyruvate kinase and glucose-6-phosphate dehydrogenase enzymes in the blood; histochemical features of glycogen distribution in liver of rats with impaired glucose tolerance. Materials and methods: Diabetes in rats was induced by intra-abdominal injection of a 5% solution of alloxan monohydrate at the rate of 170 mg/kg of body weight. Four days after animals were divided into rats with impaired glucose tolerance and melatonin-group with impaired glucose tolerance (5 mg/ kg «Sigma» USA, daily and intraperitoneal for 42 days starting from 5th day). Impaired glucose tolerance was determined by measurement of glucose profiles - fasting <5.6 mmol/l; postprandial (2h post-load) 7.8 - 11.0 mmol/l. Histochemical examination of the liver was performed according to the standard method of PAS-reaction staining. Statistical analysis was performed using Statistica 10 StatSoft Inc. Results: Pyruvate kinase activity in erythrocytes and optical density of glycogen in hepatocytes of animals with impaired glucose tolerance decreased on 18% and 11%, activity of glucose-6-phosphate dehydrogenase and content of malondialdehyde increased on 35% and 23%, respectively compared with the control. We have reached the recovery of the pyruvate kinase and normalization of glucose-6-phosphate dehydrogenase activities, malondialdehyde levels, glucose profiles in the blood as well as glycogen distribution in the liver caused by melatonin injections. Conclusions: We have determined that long term melatonin injections did better glucose tolerance in rats.

Oxidative stress and histopathological changes in several organs of mice injected with biogenic silver nanoparticles

The widespread use of silver nanoparticles (AgNPs) requires a study of their safety. The aim of the present study was to assess the levels of oxidative stress markers and histopathological changes in the experimental model of sarcoma S-180 of outbred mice caused by biogenic AgNPs. AgNPs were synthesized using 50% ethanol extract of Ocimum araratum leaves that was standardized for rosmarinic acid content. The effects of AgNPs were tested on chemiluminescence (ChL), malonic dialdehyde (MDA) content and activity of superoxide dismutase (SOD) in healthy and experimental model of sarcoma S-180 mice. It was shown that, under the influence of AgNPs, the intensity of ChL decreased, in contrast with control groups (with the exception of the hepatocytes of animals with transplanted sarcoma). The presence of AgNPs leads to the decrease of MDA in the tissues of healthy mice and to a slight increase of MDA content in the tumour and kidney tissues. AgNPs neutralize the activity of SOD in kidney tissue samples in animals with transplanted sarcoma, and in tumour tissue, they reduce SOD activity by three times. The results of the histological analysis indicate that AgNPs not only cause the destruction of tumour tissue but also lead to structural changes in hepatocytes and nephrons, which can affect the function of these organs. AgNPs are potential agents for antitumor therapy. Future studies are needed using biocompatible non-toxic NPs that meet the requirement for these drugs.

Preclinical study of the effects of vitamin-mineral complex use during normal pregnancy in white rats

Vitamin-mineral deficiency is quite common in the world, which negatively affects the growth and development of children, provokes the development of chronic pathologies, allergic conditions. Children and pregnant women are particularly sensitive to this condition. Considering the vitamin and elemental composition of each of the drugs, it becomes necessary to examine the effect of various complexes on the body. The purpose of the study is to examine the morphological state of organs from the use of a vitamin-mineral complex during normal pregnancy in white rats and their offspring and examine the elemental analysis of target organs and whole blood. The experiment was conducted on pregnant female white laboratory rats and their offspring to achieve this goal. Histological, ultramicroscopic, morphometric, atomic-absorptic, functional methods, and statistical analysis are used for the study. A positive effect of the vitamin-mineral complex of the selected composition on both pre- and postnatal development of offspring is identified. The average offspring rate increased by 9.79% (p = 0.0443), while the stillbirth rate decreased by 81.82% (p = 0.0324). The absence of negative side effects of the complex on the development of basic reflex and behavioural reactions, motor activity, and cognitive activity of offspring is proved. A positive effect on the morphological characteristics of the liver, brain, heart, and kidneys is evident: the number of full hepatocytes in mature animals increased by 8.17% (p = 0.0482), and in young animals – by 5.03% (p = 0.0137), in the brain tissue of 7-day-old animals, the number of neurons increased by 7.70% (p = 0.0438), and the number of functionally defective neurons decreased. Microelement analysis of organs identified a tendency to increase the amount of a number of trace elements, which was reflected in the improvement of the antioxidant systems pf the body. A positive effect of the complex on the processes of hematopoiesis is noted. The results obtained can become morphological evidence for the choice of correction of macro-, microelement, and vitamin balance, prevention of its deficiency in pregnant women, and prevention of the development of deficient conditions in infants

English

Breast cancer is prevalent among women worldwide. African walnut (Tetracarpidium conophorum) seeds extract have been shown to have medicinal properties. This study is to determine the effects of feeding T. conophorum seeds lipid extract on 3-methylcholanthrene (MC) induced breast carcinogenesis and the expression of ethoxyresorufin-O-deethylase (CYP1A1), benzoxyresorufin-O-dealkylase (CYP1B1) and pentoxyresorufin-O-dealkylase (CYP2B1). The lipid was extracted using Soxhlet apparatus with n-hexane. Forty-five female Wistar rats of 21 days old were used, which were randomly divided into three major groups of 15 animals each. Groups A and B were fed for 12 weeks with diet containing T. conophorum seeds lipid extract (10%), and group B animals were administered MC (200 mg/kg body weight) intraperitoneally after 4 weeks of feeding. Group C animals were fed for 12 weeks with diet containing no T. conophorum seeds lipid extract and administered MC (200 mg/kg body weight) intraperitoneally after 4 weeks of feeding. Results indicated that CYP1A1, CYP1B1 and CYP2B1 were significantly (p &lt; 0.05) reduced in Group B animals liver cells compared to group C with higher expression. Prolonged latency period, reduce tumor weight and size characterized group B animals compared to group C. Histopathology results showed normal morphology of the liver hepatocytes of animals in group B, while necrosis and steatosis were seen in group C. This study therefore showed that T. conophorum seeds lipid extract contains bioactive components that may oppose breast carcinogenesis induced by MC. &nbsp; Key words: 3-Methylcholanthrene, carcinogenesis, Tetracarpidium conophorum, fatty acids.

Modification of liver reparative regeneration in laboratory animals after partial hepatectomy

Objective. To investigate the effect of cytoflavin on the adaptive liver growth after partial hepatectomy (PH).&#x0D; Materials and methods. An experimental study was conducted on 60 male white mice aged 78 months, weighing 2431 g. All animals were divided into three groups: group 1 intact mice; group 2 operated control mice, who received saline NaCl instead of the drug; group 3 the main group of animals, who underwent partial hepatectomy, after which they received сytoflavin. Partial hepatectomy was performed by Claudia Mitchell and Holger Willenbring technique (2008). The preparation cytoflavin (Russia) was injected intraperitoneally at a dose of 0.014 ml /10 g of body weight for 7 days once daily. Morphological and morphometric studies of hepatobiopsy specimens were conducted. Statistical analysis was carried out using the methods of nonparametric statistics.&#x0D; Results. It was found that 3 days after PH, in the liver of animals of the main group, the number of dystrophically altered hepatocytes decreased by 25 times, the mitotic index increased against the background of the preserved radial-beam structure. There was an increase in the size of the cytoplasm and nucleus by 1.5 times relative to the intact group (p 0.05), that is associated with adaptive hypertrophy. At the same time, on the 3rd day, in the control group the number of dystrophically altered cells was several times higher than in the intact animals and was accompanied by an increase in the cytoplasm of hepatocytes as a result of vacuolar degeneration after PH.&#x0D; Conclusions: The use of cytoflavin leads to an increase in the mitotic activity of the partially resected liver, while the level of binuclear cells decreases. The manifestations of hepatocyte dystrophy also decrease. Comparison of the dynamics of the morphometric parameters of hepatocytes in animals of the control group and those who received cytoflavin after PH suggests that the studied drug stimulates the recovery processes in the liver during induced regeneration.

Chronic treatment with dapagliflozin protects against mitochondrial dysfunction in the liver of C57BL/6NCrl mice with high-fat diet/streptozotocin-induced diabetes mellitus

Dapagliflozin (DAPA), a selective inhibitor of sodium/glucose cotransporter SGLT2, is currently used as a hypoglycemic agent in the treatment of diabetes mellitus. In this work, we have assessed the effect of DAPA treatment (1 mg/kg/day) on the ultrastructure and functions of the liver mitochondria of C57BL/6NCrl mice with type 2 diabetes mellitus (T2DM) induced by a high-fat diet combined with low-dose streptozotocin injections. An electron microscopy study showed that DAPA prevented the mitochondrial swelling and normalized the average mitochondrial size in hepatocytes of diabetic animals. The treatment with DAPA reversed the decline in the mtDNA copy number in the liver of diabetic mice. DAPA-treated T2DM mice showed increased expression of the Ppargc1a, Mfn2 and Drp1 in the liver tissue. The treatment of diabetic animals with DAPA normalized the mitochondrial respiratory control ratio, significantly decreased the level of lipid peroxidation products in liver mitochondria, and decreased their resistance to the opening of the mitochondrial permeability transition pore. At the same time, DAPA had no effects on the studied parameters of control animals. The paper discusses the possible mechanisms of the effect of dapagliflozin on mitochondrial dysfunction in the liver of diabetic animals.

Pengaruh Pemberian Teh Kombucha Konsentrasi 50% dengan Waktu Fermentasi yang Berbeda pada Struktur Histologi Hepar Tikus Wistar (Rattus norvegicus) Jantan

This study was conducted to determine the effect of 6 kombucha fermented tea (P1), 9 (P2) and 12 (P3) fermentation days at a concentration of 50% on the liver histological structure and hepatocyte diameter. This study used 16 male white rats consisting of 4 treatments and 4 replications. The treatment of this study consisted of P0: control treatment; P1, P2 and P3 respectively were given 6, 9 and 12 days fermented kombucha tea at a concentration of 50%. This research uses a completely randomized design. The variable measured in this study was the diameter of hepatocytes in test animals. The data obtained were analyzed using Analysis of Variance (ANOVA) at a 95% confidence level and if there were real differences, followed by Duncan's test. The results of data analysis showed that kombucha tea fermented 6, 9 and 12 days with a 50% concentration did not have a significant difference in hepatocyte diameter variables. The histological structure of the liver looks normal and shows no sign of cell damage. It can be concluded that kombucha tea at a concentration of 50% is safe for consumption by mammals because it does not cause liver damage.

Aging-Related Changes in the Ultrastructure of Hepatocytes and Cardiomyocytes of Elderly Mice Are Enhanced in ApoE-Deficient Animals.

Biological aging is associated with various morphological and functional changes, yet the mechanisms of these phenomena remain unclear in many tissues and organs. Hyperlipidemia is among the factors putatively involved in the aging of the liver and heart. Here, we analyzed morphological, ultrastructural, and biochemical features in adult (7-month-old) and elderly (17-month-old) mice, and then compared age-related features between wild type (C57Bl/6 strain) and ApoE-deficient (transgenic ApoE−/−) animals. Increased numbers of damaged mitochondria, lysosomes, and lipid depositions were observed in the hepatocytes of elderly animals. Importantly, these aging-related changes were significantly stronger in hepatocytes from ApoE-deficient animals. An increased number of damaged mitochondria was observed in the cardiomyocytes of elderly animals. However, the difference between wild type and ApoE-deficient mice was expressed in the larger size of mitochondria detected in the transgenic animals. Moreover, a few aging-related differences were noted between wild type and ApoE-deficient mice at the level of plasma biochemical markers. Levels of cholesterol and HDL increased in the plasma of elderly ApoE−/− mice and were markedly higher than in the plasma of elderly wild type animals. On the other hand, the activity of alanine transaminase (ALT) decreased in the plasma of elderly ApoE−/− mice and was markedly lower than in the plasma of elderly wild type animals.

Arachidonic acid modulated lipid metabolism and improved productive performance of striped bass (Morone saxatilis) juvenile under sub- to optimal temperatures

The present study aimed to investigate the effects of different dietary arachidonic acid (ARA) levels on lipid metabolism, productive performance and biological indexes of striped bass exposed to different temperatures. Within this purpose, four isoproteic (44% of crude protein) and isolipidic (11% of lipid) experimental diets were formulated based on defatted meals and different lipid sources. Fish oil was used as primary lipid source in the control diet (FO), whereas a mixture of coconut, peanut, eicosapentaenoic acid (EPA) and docosaexaenoic acid (DHA) oils, and different amount of ARA was added to three experimental diets (ARA1–0.3%, ARA2–0.7%, and ARA3–1.2%). Additionally to the ARA, differences in the levels of specific fatty acids as 16:0, 16:1, 18:1n-9 and EPA were observed between FO and ARA diets. Morone saxatilis (striped bass) juveniles (5.31 ± 0.18 g), were distributed (30 fish) into each tank (12; with 500 L water volume) in triplicate groups. All fish were exposed to the same temperature, which was raised every fourteen days to a higher temperature (14, 18, 22, and 26 °C). All dietary treatment remained 14 days at each temperature and an additional seven acclimation days to the new temperature. After seventy-seven days of the feeding trial, a decrease in growth and mainly survival rate were observed in fish fed the FO diet, compared to the rest of the treatments. Our results suggested that different diets composition, mostly higher dietary ARA influenced greater feed intake, weight gain, and especially survival. ARA was efficiently retained in liver and fillet at higher temperatures, while at lower temperatures, it was probably synthesized in other compounds, such as prostaglandins. Additionally, the temperature rise influenced a higher lipid deposition in hepatocytes of animals from all experimental groups. Dietary ARA and temperature modulated the expression of genes related to the prostaglandin synthesis and fatty acid synthesis and catabolism. It is concluded that ARA, such as DHA, is an essential fatty acid needed at higher levels (0.7 to 1.2% in diet), especially when fish is exposed to low sub-optimal temperatures. While when fish oil was used in the control diet (containing 0.33% ARA), fish not only decrease in body mass but compromise its physiological status, resulting in mass mortalities when the temperature reached the optimum range for this species.

Ultrastructure of Hepatocytes from Laboratory Mice Fed a Standard Dry Laboratory Animal Diet.

The significant destructive changes in ultrastructure of hepatocytes from laboratory mice kept in different vivariums in Moscow and fed with dry laboratory animal diets acquired from different domestic manufacturers that were not standardized for initial products were demonstrated using electron microscopy. Furthermore, disruption in the ultrastructure of liver parenchymal cells occurred regardless of the animal status (SPF or conventional), conditions of various vivariums, as well as the feed manufacturer. At the same time, studies on ultrastructure of liver hepatocytes from mice kept in the Charles River Laboratory facilities in Germany and fed with the Altromin Spezialfutter laboratory animal diet (GmbH & Co., Germany) that was produced using quality control of ingredients did not reveal destructive changes in the internal ultrastructure of hepatocytes. However, if these mice were later fed with the food produced in local manufactures, changes in the structure of liver cells developed after 2 months. Thus, feeding with dry diet from the domestic producers of an unspecified composition causes significant changes in the ultrastructure of hepatocytes in control animals, reflecting the development of some pathological processes in the body.

A study on hepatopathic, dyslipidemic and immunogenic properties of fructosylated-HSA-AGE and binding of autoantibodies in sera of obese and overweight patients with fructosylated-HSA-AGE.

Over consumption of fructose may lead to obesity and dyslipidemia and cause fructosylation-induced alterations in the structure and function of proteins. The aim of this study was to investigate the role of fructosylated-HSA-AGE in the pathogenesis of fatty liver (NAFLD and NASH) by biochemical, immunological and histological studies. Immunogenicity of fructosylated-HSA-AGE was probed by inducing antibodies in rabbits. Fructosylated-HSA-AGE was found to be highly immunogenic. Furthermore, fructosylated-HSA-AGE caused mild fibrosis with steatosis and portal inflammation of hepatocytes in experimental animals. Liver function test and dyslipidemic parameters in immunized animals were also found to be raised. Ultrasonography, which should form part of the assessment of chronically raised transaminases, shows fatty infiltration. Interestingly, alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, total cholesterol (TC) and triglyceride (TG) profiles confirms USG images of overweight, obese patients. Thus, present study demonstrates that fructosylated-HSA-AGE is hepatotoxic, immunologically active and may cause dyslipidemia.

Hepatic Rac1 GTPase contributes to liver-mediated basal immune homeostasis and LPS-induced endotoxemia

BackgroundThe Ras-homologous GTPase Rac1 plays a key role in the regulation of gene expression, cytoskeleton-associated processes and cell death as well as carcinogenesis and inflammation. Here, we investigated the impact of Rac1 signaling on liver-mediated immune homeostasis. MethodsWe employed a constitutive Alb-Cre-driven rac1 knock-out and a poly I:C-inducible Mx1-Cre-based knock-out model and analyzed cytokine expression profiles in liver and other organs under basal situation and following LPS-induced endotoxemia by flow cytometry, qRT-PCR and immunocytochemistry. ResultsConstitutive Alb-Cre-driven rac1 knockout in hepatocytes altered the basal distribution and activation of immune cells in the liver and likewise in kidney and lung. Early systemic alterations in cytokine serum levels following LPS treatment remained unaffected by Rac1. Furthermore, lack of Rac1 in hepatocytes of untreated animals shifted the liver to a chronic inflammatory state, as depicted by an enhanced mRNA expression of marker genes related to activated macrophages. Upon acute LPS-induced endotoxemia, increased IL-10 mRNA expression in the liver of Alb-Cre Rac1-deficient mice provided an anti-inflammatory response. Employing a poly I:C-inducible Mx1-Cre-based rac1 knock-out, which allows a more widespread rac1 deletion in both hepatocytes and non-hepatocytes, we observed substantial differences regarding both basal and LPS-stimulated cytokine expression profiles as compared to the Alb-Cre system. ConclusionsRac1-dependent mechanisms in hepatocytes and non-hepatocytes contribute to the maintenance of liver immune homeostasis under basal situation and following LPS-induced endotoxemia. Disturbed Rac1-regulated hepatocyte functions may promote liver damage under pathophysiological situation involving inflammatory stress.

Long-term effects of low-dose mouse liver irradiation involve ultrastructural and biochemical changes in hepatocytes that depend on lipid metabolism.

The aim of the study was to investigate long-term effects of radiation on the (ultra)structure and function of the liver in mice. The experiments were conducted on wild-type C57BL/6J and apolipoprotein E knock-out (ApoE-/-) male mice which received a single dose (2 or 8Gy) of X-rays to the heart with simultaneous exposure of liver to low doses (no more than 30 and 120mGy, respectively). Livers were collected for analysis 60weeks after irradiation and used for morphological, ultrastructural, and biochemical studies. The results show increased damage to mitochondrial ultrastructure and lipid deposition in hepatocytes of irradiated animals as compared to non-irradiated controls. Stronger radiation-related effects were noted in ApoE-/- mice than wild-type animals. In contrast, radiation-related changes in the activity of lysosomal hydrolases, including acid phosphatase, β-glucuronidase, N-acetyl-β-D-hexosaminidase, β-galactosidase, and α-glucosidase, were observed in wild type but not in ApoE-deficient mice, which together with ultrastructural picture suggests a higher activity of autophagy in ApoE-proficient animals. Irradiation caused a reduction of plasma markers of liver damage in wild-type mice, while an increased level of hepatic lipase was observed in plasma of ApoE-deficient mice, which collectively indicates a higher resistance of hepatocytes from ApoE-proficient animals to radiation-mediated damage. In conclusion, liver dysfunctions were observed as late effects of irradiation with an apparent association with malfunction of lipid metabolism.

Evaluation of acute toxicity of β-lapachone associated with chitosan as a cytoprotective agent

ABSTRACT INTRODUCTION: β-lapachone (β-LAP), a potent antitumor agent, has limited therapeutic use due to its low solubility and high toxicity. A possible strategy to overcome these drawbacks may be the use of adjuvants such as chitosan (CS), a cationic polysaccharide with biological properties of biocompatibility and biodegradability. OBJECTIVE: Evaluate the adjuvant action of CS as a cytoprotectant associated with β-LAP, through acute toxicity studies, evaluating histopathological changes in organs such as liver and kidneys. METHODS: The β-LAP-CS conjugate was prepared in a 1:1 ratio, administered orally, with a single dose of β-LAP of 80 mg/kg, in Swiss mice. Histomorphological and histomorphometric analyses of the kidneys and liver were performed. RESULTS: In the histomorphological studies of the tested groups, we observed that the hepatocytes of animals treated with the free drug presented morphological alterations, such as cytoplasmic vacuolization, cellular extravasation, atypical and pyknotic nuclei. In this same group, the kidneys presented granular aspects suggestive of glomerulonephritis. These changes were not found in the control group and in animals treated with CS-conjugated β-LAP. There was no statistical difference in the histomorphometric analyses of the distal tubules and the renal glomeruli between the three groups analyzed, even with evident histomorphological alterations. After histomorphometric studies, it was observed that the area of hepatocytes and their cell nuclei presented a statistically significant difference between the animals treated with free β-LAP and the β-LAP-CS. CONCLUSION: The decrease in β-LAP toxicity after conjugation may be related to the hepatoprotective property of CS.

Glucocorticoid treatment facilitates development of a metabolic syndrome in ovariectomized Macaca Mulatta fed a high fat diet

Metabolic syndrome (MetS) is characterized by a cluster of key features, which include abdominal obesity, insulin resistance, hypertension, and dyslipidemia. The aim of this study was to assess the impact of elevated glucocorticoid levels on the development of MetS in middle-aged female rhesus monkeys (Macaca Mulatta) after ovariectomy. Six female ovariectomized rhesus monkeys (9–13years) were randomly assigned to either a control group (normal diet, n=3) or a group in which MetS was facilitated (n=3). The MetS group fed with HFD (15% fat) and received oral prednisone acetate treatment (50mg/day). After 24months, the GCs treatment was withdrawn with continuation of high-fat feeding for a further 12months. After 24months, the MetS group displayed a significant increase in body weight and abdominal circumference. Additionally, the MetS animals displayed abnormal serum lipids, insulin resistance and impaired glucose tolerance. Histology of liver biopsies indicated marked accumulation of lipid droplets in hepatocytes of MetS animals. Withdrawal of GCs treatment led to recovery from above-mentioned metabolic disorders. Whereas GCs treatment increased leptin expression, it lowered expression of adiponectin and other factors in adipose tissue. Expression of Hydroxy-steroid dehydrogenase-1 and glucose transporter type-4 in the livers of MetS animals were reduced. We conclude that in the context of high fat diet, high levels of exogenous GCs contribute to the development of MetS in non-human primates.