Liver Cell Nuclei Research Articles

Biological Mechanisms of Aflatoxin B1-Induced Bile Metabolism Abnormalities in Ducklings.

This study investigated the effects and biological mechanisms of aflatoxin B1 (AFB1) on the health and bile metabolism of ducklings. Forty-eight 1-day-old ducklings were randomly assigned to two groups, with six replicates per group. The control group was fed a basic diet, while the AFB1 group received a diet containing 90 µg/kg of AFB1. The experiment lasted for 2 weeks. The results showed that 90 µg/kg AFB1 caused abnormal bile metabolism; damaged liver cell nuclei and mitochondria; and significantly decreased body weight, average daily weight gain, and levels of albumin, total protein, cholesterol, total superoxide dismutase, glutathione peroxidase, and glutathione. It also significantly increased feed conversion efficiency, along with alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bile acids, and malondialdehyde levels. In the liver, the expression levels of CYP7A1, SCD, and other genes were significantly upregulated, while BSEP, FASN, HMGCR, CAT, and other genes were significantly downregulated. In conclusion, AFB1 causes abnormal bile metabolism and impairs the overall health and liver function of ducklings. Its mechanism of action may involve changes in gene expression related to bile acid metabolism, lipid metabolism, oxidative damage, and cancer pathways.

TBHQ mitigates fatty liver ischemia–reperfusion injury by activating Nrf2 to attenuate hepatocyte mitochondrial damage and macrophage STING activation

BackgroundLiver ischemia–reperfusion (IR) injury is an inevitable pathophysiological process in various liver surgeries. Previous studies have found that IR injury is exacerbated in fatty liver due to significant hepatocellular damage and macrophage inflammatory activation, though the underlying mechanisms are not fully understood. In this study, we aim to explore the role and mechanism of Nrf2 (Nuclear factor erythroid 2-related factor 2) signaling in regulating hepatocellular damage and macrophage immune response in fatty liver IR injury. MethodsThe study used high-fat diet-induced fatty liver mice to establish an IR model, alongside an in vitro co-culture system of primary hepatocytes and macrophages. This approach was used to examine mitochondrial dysfunction, oxidative stress, mitochondrial DNA (mtDNA) release, and activation of macrophage STING (Stimulator of interferon genes) signaling. We also conducted recovery verification using H-151 (a STING inhibitor) and tBHQ (an Nrf2 activator). ResultsCompared to the control group, mice on a high-fat diet demonstrated more severe liver IR injury, as evidenced by increased histological damage, elevated liver enzyme levels, and heightened inflammatory markers. The HFD group showed significant oxidative stress and mitochondrial dysfunction and damage post-IR, as indicated by elevated levels of ROS and lipid peroxidation markers, and decreased antioxidant enzyme activity. Elevated mtDNA release from hepatocytes post-IR activated macrophage STING signaling, worsening inflammation and liver damage. However, STING signaling inhibition with H-151 in vivo or employing STING knockout macrophages significantly reduced these injuries. In-depth mechanism studies have found that the transfer of Nrf2 protein into the nucleus of liver cells after IR in fatty liver is reduced. Pre-treatment with tBHQ ameliorated liver oxidative stress, mitochondrial damage and suppressed the macrophage STING signaling activation. ConclusionsOur study reveals a novel mechanism where the interaction between hepatocellular damage and macrophage inflammation intensifies liver IR injury in fatty liver. Enhancing Nrf2 activation to protect mitochondrial from oxidative stress damage and inhibiting macrophage STING signaling activation emerge as promising strategies for clinical intervention in fatty liver IR injury.

Water extract of earthworms mitigates mouse liver fibrosis by potentiating hepatic LKB1/Nrf2 axis to inhibit HSC activation and hepatocyte death

Ethnopharmacological relevanceWhen left untreated, liver fibrosis (LF) causes various chronic liver diseases. Earthworms (Pheretima aspergillum) are widely used in traditional medicine because of their capacity to relieve hepatic diseases.Aim of the study: This study aimed to explore the anti-LF effects of water extract of earthworms (WEE) and the underlying molecular mechanisms. Materials and methodsA CCl4-induced mouse model of LF was used to study the impact of WEE on LF in vivo. The anti-LF activity of WEE in mice was compared with that of silybin, which can be clinically applied in LF intervention and was used as a positive control. Activation of LX-2 hepatic stellate cells (HSCs) and apoptosis and ferroptosis of AML-12 hepatocytes induced by TGFβ1 were used as in vitro models. ResultsWEE drastically improved LF in mice. WEE reduced markers of activated HSCs in mice and inhibited TGFβ1-induced activation of LX-2 HSCs in vitro. Additionally, WEE suppressed CCl4-induced apoptosis and ferroptosis in mouse hepatocytes. Mechanistically, WEE induced Nrf2 to enter the nuclei of the mouse liver cells, and the hepatic levels of Nrf2-downstream antioxidative factors increased. LKB1/AMPK/GSK3β is an upstream regulatory cascade of Nrf2. In the LF mouse model, WEE increased hepatic phosphorylated LKB1, AMPK, and GSK3β levels. Similar results were obtained for the LX-2 cells. In AML-12 hepatocytes and LX-2 HSCs, WEE elevated intracellular Nrf2 levels, promoted its nuclear translocation, and inhibited TGFβ1-induced ROS accumulation. Knocking down LKB1 abolished the impact of WEE on the AMPK/GSK3β/Nrf2 cascade and eliminated its protective effects against TGFβ1. ConclusionsOur findings reveal that WEE improves mouse LF triggered by CCl4 and supports its application as a promising hepatoprotective agent against LF. The potentiation of the hepatic antioxidative AMPK/GSK3β/Nrf2 cascade by activating LKB1 and the subsequent suppression of HSC activation and hepatocyte apoptosis and ferroptosis are implicated in WEE-mediated alleviation of LF.

Investigation of nuclear DNA content and cell cycle phases in rat liver cells under chlorpromazine administration

Hepatotoxicity of antipsychotic drugs remains an urgent problem of modern medicine. Therefore, the purpose of the study was to investigate the nuclear DNA content and cell cycle phases of rat liver cells under Сhlorpromazine administration at doses ranging from 3.5 mg/kg to 28 mg/kg for 30 and 60 days. The study was conducted on 60 sexually mature female rats. Chlorpromazine was administered once daily for 30 and 60 days at doses of 3.5 mg/kg, 7 mg/kg, 14 mg/kg, 21 mg/kg and 28 mg/kg. The DNA content in the nuclei of rat liver cells was determined by flow cytometry. Cytological analysis of cells was performed using FloMax software (Partec, Germany), where the percentage of nuclei in the G0G1 interval of the cell cycle, in the S phase, G2M interval, and the apoptosis index – SUB-G0G1 area on DNA histograms were determined. Statistical processing of the results was performed using the Mann-Whitney U test. The results of the study showed that Сhlorpromazine has a dose-dependent hepatotoxic effect: with an increase in the dose of this drug in rats from 7 to 28 mg/kg, the percentage of fragmented nuclei in liver tissue significantly increased, which is a sign of hepatocyte death by apoptosis. It was found that Сhlorpromazine at a dose of 3.5 mg/kg did not increase hepatocyte apoptosis, while at a dose of 21 and 28 mg/kg the drug showed the highest hepatotoxicity, increasing the level of apoptosis by 1.9 and 2.1 (p˂0.05) times, respectively. The hepatotoxic effect is enhanced by the use of Сhlorpromazine for 60 days, which is manifested in a significant increase in hepatocyte nuclear DNA fragmentation, which, in our opinion, should be taken into account when conducting long-term therapy in patients.

The histopathological changes of liver and testis of Japanese quail chicks fed different levels of dietary L-valine

This experiment was carried out to investigate the histological changes of liver and testis of Japanese quail fed different levels of dietary valine (Val) in low protein diet. A total of 1000 one-day-old Japanese quail chicks (mixed sex) were assigned to five experimental diets including diets containing 7.5, 8.5, 9.5, 10.5 and 11.5 g digestible (dig.) Val/kg diet in a completely randomized design, with 5 replicates of 40 quail chicks per pen. Experimental diets were formulated to be isoenergetic and isonitrogenous (170 g crude protein/kg) to meet nutrients recommendation of growing quails suggested by Brazilian tables. At d 42, quail chicks were slaughtered, and tissue samples were collected and fixed to evaluate the histological indices of liver and testis. High levels of Val, increased (P < 0.05) diameter of liver cell nucleus and liver hepatocytes in both male and female. While 11.5 g Val showed mild hepatosteatosis, bile duct hyperplasia was observed in 10.5 g Val. In 7.5 and 8.5 g Val groups, there was no negative effects on the liver histology. The male quail chicks which fed on diets containing 8.5 g Val had better significant (P < 0.05) reproductive indexes [Tubular differentiation (TDI) and spermatic index (SI)]. In conclusion, the use of high levels of Val (≥ 9.5 g dig. Val/kg diet) during d 0 – 42 of age can lead to histological damage in liver and testis of quail chicks.

The ubiquitin ligase Uhrf2 is a master regulator of cholesterol biosynthesis and is essential for liver regeneration.

Fibroblast growth factors (FGFs) are key regulators of the remarkable regenerative capacity of the liver. Mice lacking FGF receptors 1 and 2 (Fgfr1 and Fgfr2) in hepatocytes are hypersensitive to cytotoxic injury during liver regeneration. Using these mice as a model for impaired liver regeneration, we identified a critical role for the ubiquitin ligase Uhrf2 in protecting hepatocytes from bile acid accumulation during liver regeneration. During regeneration after partial hepatectomy, Uhrf2 expression increased in an FGFR-dependent manner, and Uhrf2 was more abundant in the nuclei of liver cells in control mice compared with FGFR-deficient mice. Hepatocyte-specific Uhrf2 knockout or nanoparticle-mediated Uhrf2 knockdown caused extensive liver necrosis and impaired hepatocyte proliferation after partial hepatectomy, resulting in liver failure. In cultured hepatocytes, Uhrf2 interacted with several chromatin remodeling proteins and suppressed the expression of cholesterol biosynthesis genes. In vivo, the loss of Uhrf2 resulted in cholesterol and bile acid accumulation in the liver during regeneration. Treatment with a bile acid scavenger rescued the necrotic phenotype, hepatocyte proliferation, and the regenerative capacity of the liver in Uhrf2-deficient mice subjected to partial hepatectomy. Our results identify Uhrf2 as a key target of FGF signaling in hepatocytes and its essential function in liver regeneration and highlight the importance of epigenetic metabolic regulation in this process.

False positivity in break apart fluorescence in-situ hybridization due to polyploidy.

In-situ hybridization (ISH) is a diagnostic tool in the detection of chromosomal anomalies, which has important implications for diagnosis, classification and prediction of cancer therapy in various diseases. Certain thresholds of number of cells showing an aberrant pattern are commonly used to declare a sample as positive for genomic rearrangements. The phenomenon of polyploidy can be misleading in the interpretation of break apart fluorescence in-situ hybridization (FISH). The aim of this study is to investigate the impact of cell size and ploidy on FISH results. In sections of varying thickness of control liver tissue and non-small cell lung cancer cases, nuclear size was measured and the number of MET chromogenic ISH and ALK FISH (liver) or ALK and ROS1 FISH (lung cancer) signals was manually counted and quantified. In liver cell nuclei the number of FISH/chromogenic ISH signals increases with nuclear size related to physiological polyploidy and is related to section thickness. In non-small cell lung cancer cases tumour cells with higher ploidy levels and nuclear size have an increased chance of single signals. Furthermore, additional lung cancer samples with borderline ALK FISH results were examined with a commercial kit for rearrangements. No rearrangements could be demonstrated, proving a false positive ALK FISH result. In case of polyploidy there is an increased likelihood of false positivity when using break apart FISH probes. Therefore, we state that prescribing one single cut-off in FISH is inappropriate. In polyploidy, the currently proposed cut-off should only be used with caution and the result should be confirmed by an additional technique.

α7 Nicotinic acetylcholine receptors regulate translocation of HIF-1α to the cell nucleus and mitochondria upon hypoxia

Nicotinic acetylcholine receptors (nAChRs), initially characterized as ligand-gated ion channels mediating fast synaptic transmission, are now found in many non-excitable cells and mitochondria where they function in ion-independent manner and regulate vital cellular processes like apoptosis, proliferation, cytokine secretion. Here we show that the nAChRs of α7 subtype are present in the nuclei of liver cells and astrocytoma U373 cell line. As shown by lectin ELISA, the nuclear α7 nAChRs are mature glycoproteins that follow the standard rout of post-translational modifications in Golgi; however, their glycosylation profile is non-identical to that of mitochondrial nAChRs. They are exposed on the outer nuclear membrane and are found in combination with lamin B1. The nuclear α7 nAChRs are up-regulated in liver within 1 h after partial hepatectomy and in H2O2-treated U373 cells. As shown both in silico and experimentally, the α7 nAChR interacts with hypoxia-inducible factor HIF-1α and this interaction is impaired by α7-selective agonists PNU282987 and choline or type 2 positive allosteric modulator PNU120596, which prevent HIF-1α accumulation in the nuclei. Similarly, HIF-1α interacts with mitochondrial α7 nAChRs in U373 cells treated with dimethyloxalylglycine. It is concluded that functional α7 nAChRs influence HIF-1α translocation into the nucleus and mitochondria upon hypoxia.

Effect of Cefotaxime Administration on the kidney, liver and Lung of Swiss white Mice (mus musculus)

The present study was designed to monitor the impact a drug such as cefotaxime has on the histological architecture of the kidney, liver and Lung on Swiss white mice.&#x0D; The experiment was designed by using 30 Swiss white mice from both sexes.&#x0D; &#x0D; Mice were classified randomly into three groups:&#x0D; &#x0D; Group A: Control Group, injected intramuscularly with 0.5ml distilled water daily for 6 days.&#x0D; Group B: Therapeutical Dose, Injected intramuscularly with 0.1 ml cefotaxime daily for 6 days.&#x0D; Group C: Extra Therapeutical Dose, Injected with 0.2 ml cefotaxime daily for 6 days.&#x0D; At the end of the experimental period, the kidney, liver and lung of the mice were taken and processed for histological study.&#x0D; The behavioral results showed a lower appetite and decrease in weight in the mice present in Group C.&#x0D; Histologically,the kidney and liver showed numerous abnormalities at the end of the treatment period compared to that of the control group.&#x0D; Pyknosis, Karyohyxis and Karyolysis were found in the liver cell nuclei.&#x0D; While infiltration of the lymphocytes was present. Necrosis of the hepatocytes were observed clearly throughout the tissue present in the lung.&#x0D; Renal convoluted tubules show atrophy and necrosis of cell with hypertrophy of glomeruli.&#x0D; Degeneration and shrinkage of the renal tubule cells with the appearance of pyknosis of nuclei was also found.&#x0D; Due to these destructive results on the liver and kidney cells it was concluded that cefotaxime caused many cell abnormalities and dysfunction in general.

Evaluation of the Toxicity of Dichlorodiphenyl-trichloroethane (DDT) to the Expression Levels of Three Genes p53, rarα1, wnt in the Embryos and Liver of Fish Medaka Oryzias latipes

Three genes p53, rarα1, wnt and liver of Medaka fish tissue were selected to study the toxicity of DDT to fish embryo (8 days old) and adult Medaka fish (3 months old). TEM and real-time PCR methods were used to examine changes in structure of liver tissue and genetic expression. The TEM results recorded a clear difference between the control and the experimental sample. Adult Medaka fish exposed to 1µg/L DDT for 24 hours has a distorted liver cell nucleus with many hollow lipid particles, and the sinus-shaped meshes are clustered, interrupted; lysosome is not intact with many degenerative bubbles. The results of real-time PCR analysis showed that DDT affects the development, different and proliferation of cells in the embryonic stage and gene expression in adult stage. All three genes p53, rarα1 and wnt in fish embryos changed strongly and tended to be inhibited when exposuring with 1700µg/L DDT, the values ​​were recorded respectively 0.9; 4.9 and 5.4 times compared to the control sample (1 times). For adult fish, gene expression was lower than fish embryos with real-time PCR analysis values ​​for the three genes p53, rarα1 and wnt respectively 0.9 and 0.5; 0.36 and 0.09; 0.53 and 0.09 times after exposure to 1500 and 1700 µg/L DDT. These results demonstrated that gene expression is dependent on the developmental stage of the cell as well as on the dose of the chemical exposed. The development, cell differentiation/proliferation in the embryonic and adulthood stages affected differently to the cell gene expression.

Pengaruh Serbuk Daun Kelor (Moringa oleifera) Terhadap Apoptosis Sel Hepar Pada Tikus Bunting Diabetes Mellitus

Maternal death rate in Indonesia are still very high. One of the causes is gestasional diabetes mellitus during pregnancy. Some of healing efforts are done, one of them was utilization of plants, in this case, Moringa oleifera. The purpose of this reseach is to know the Moringa oleifera leaf powder on the pregnant wistar rats with gestasional diabetes mellitus. The study design was laboratoric experimental on the wistar rats as the experimental animal, using Control Group Post Test Design on the research. Sample was divided into 2 positive and negative control groups and 4 treatment groups given Moringa oleifera leaf powder that will be induced by alloxan and the liver histopatological result be examined. Total average of liver cell nucleus that goes through apoptosis is lower linear with the increase of the Moringa oleifera leaf powder dose given to the treatment group. After the alloxan induction, the wistar rats’ blood glucose level is increased, caused by the destruction of the beta cell pancreas. There’s a significant difference between the liver cell that go through apoptosis between the four treatment group of wistar rats. The total average of liver cell that go through apoptosis is lower linear with the increase of the Moringa oleifera leaf powder dose given to the treatment group. Oral administration of Moringa leaf powder to white rats with diabetes mellitus was able to improve the histopathological picture of the liver where the brown color was seen to decrease while the methylene green increased. As well as lowering the blood glucose levels of the rats.

The Effect of Inhaled Anesthetic Halothane on Liver Cells (Experimental Study of Halothane Toxic Effect in BalbC Mice)

Adverse effects of halothane on the liver range from liver dysfunction to hepatitis, and are more frequent following repeated use. Medical personals are in risk of chronic exposure of wasted halothane. However, there are limited literatures about this effect based on time exposure. To identify and analyze the liver cells changes of halothane exposure to liver cells of Balb/C mice. This experimental study used randomized post-test only control group design in 30 male BalbC mice given 0.011 mg/weight halothane 3 hours daily for two weeks (group 1), four weeks (group 2), six weeks (group 3), six weeks followed by 2 weeks of halothane free (group 4), and without exposure (control group). The liver tissues were HE stained and observed for enlarge, karyorrhexis, and karyolitic of the nucleus. Immunohistochemistry was undertaken to count the percentage of cytocrome-P450 stained brown colour and scored based on its intensity. The difference among groups and between each group were statistically significant (p&lt; 0.05), except between group 2 and 4 (p = 0.078), and between group 3 and 4 (p = 0.522). The difference of cytocrome-P450 expression among groups was not statistically significant (p = 0.266). There was statistically significant difference of abnormal liver cell nucleus changes in groups with different time of halothane exposure (p = 0.000) while no statistically significant difference of cytocrome-P450 expressions (p = 0.266) was found. The nucleus changes were gradually increased with the time of exposure.

Quercetin and Allicin Can Alleviate the Hepatotoxicity of Lead (Pb) through the PI3K Signaling Pathway.

Lead (Pb) is a common toxic heavy metal pollutant in the environment that seriously endangers the health of animals. The liver is a key target organ affected by Pb toxicity. Plant extracts allicin and quercetin have a strong antioxidant capacity that can promote the excretion of heavy metals by improving the body's antioxidant defense and chelating heavy metal ions. To explore the preventive and therapeutic effects of allicin and quercetin on Pb poisoning in chickens, 96 chickens were randomly divided into eight groups: control, Pb, allicin, quercetin, allicin + quercetin, Pb + allicin, Pb + quercetin, and Pb + allicin + quercetin groups. The chickens were given feed containing the above treatments for 90 days. The results indicated that Pb can affect the growth and development of the liver, damage the circulatory system, destroy the structure of mitochondria and nuclei in liver cells, cause an imbalance in the oxidation system, inhibit PI3K protein, and activate the mitochondrial apoptotic pathway. Allicin and quercetin, alone or in combination, can improve the antioxidant capacity of the liver and alleviate liver tissue damage caused by Pb. In summary, allicin and quercetin could alleviate oxidative damage and apoptosis in the Pb-poisoned chicken liver through the PI3K signaling pathway, with stronger effects achieved by their combination.

TOXIC EFFECTS OF ULTRA-DISPERSED FORMS OF METALS (Mo AND MoO3) IN THE EXPERIMENT in vivo

TOXIC EFFECTS OF ULTRA-DISPERSED FORMS OF METALS (Mo AND MoO3) IN THE EXPERIMENT in vivo

Optimization of S. aureus dCas9 and CRISPRi Elements for a Single Adeno-Associated Virus that Targets an Endogenous Gene

The power of CRISPRi to decrease targeted gene expression for clinical applications has been inhibited by delivery challenges. Existing constructs are too large to fit within the ∼4.7 kb packaging size limitation of adeno-associated virus (AAV), the only FDA approved viral vector for clinical use. Therefore, we optimized CRISPRi components to generate a single AAV vector that contains all functional elements and effectively knocks down expression of an endogenous gene in vivo. First, we increased nuclear targeting of Staphylococcus aureus deactivated Cas9 (SadCas9) 4-fold by using a helical linker and the c-Myc nuclear localization signal. Second, we identified an amino-terminal Krüppel associated box (KRAB) construct as the most effective in decreasing expression of target genes in vitro. Third, we optimized promoters for guide RNA and evaluated mini-promoters for expression of KRAB-SadCas9 in liver cells. Our final construct decreased protein convertase subtilisin/kexin type 9 (Pcsk9) mRNA and secreted protein 5-fold in vitro. The corresponding AAV2/8 vector was localized in nuclei of liver cells and decreased Pcsk9 mRNA and serum protein levels by 30% in vivo. This single AAV approach provides a potential clinically translatable method for decreasing targeted gene transcription by CRISPRi in vivo.

NF-κB and Keap1 Interaction Represses Nrf2-Mediated Antioxidant Response in Rabbit Hemorrhagic Disease Virus Infection.

The rabbit hemorrhagic disease virus (RHDV), which belongs to the family Caliciviridae and the genus Lagovirus, causes lethal fulminant hepatitis in rabbits. RHDV decreases the activity of antioxidant enzymes regulated by Nrf2 in the liver. Antioxidants are important for the maintenance of cellular integrity and cytoprotection. However, the mechanism underlying the regulation of the Nrf2-antioxidant response element (ARE) signaling pathway by RHDV remains unclear. Using isobaric tags for relative and absolute quantification (iTRAQ) technology, the current study demonstrated that RHDV inhibits the induction of ARE-regulated genes and increases the expression of the p50 subunit of the NF-κB transcription factor. We showed that RHDV replication causes a remarkable increase in reactive oxygen species (ROS), which is simultaneously accompanied by a significant decrease in Nrf2. It was found that nuclear translocation of Keap1 plays a key role in the nuclear export of Nrf2, leading to the inhibition of Nrf2 transcriptional activity. The p50 protein partners with Keap1 to form the Keap1-p50/p65 complex, which is involved in the nuclear translocation of Keap1. Moreover, upregulation of Nrf2 protein levels in liver cell nuclei by tert-butylhydroquinone (tBHQ) delayed rabbit deaths due to RHDV infection. Considered together, our findings suggest that RHDV inhibits the Nrf2-dependent antioxidant response via nuclear translocation of Keap1-NF-κB complex and nuclear export of Nrf2 and provide new insight into the importance of oxidative stress during RHDV infection.IMPORTANCE Recent studies have reported that rabbit hemorrhagic disease virus (RHDV) infection reduced Nrf2-related antioxidant function. However, the regulatory mechanisms underlying this process remain unclear. The current study showed that the NF-κB p50 subunit partners with Keap1 to form the Keap1-NF-κB complex, which plays a key role in the inhibition of Nrf2 transcriptional activity. More importantly, upregulated Nrf2 activity delayed the death of RHDV-infected rabbits, strongly indicating the importance of oxidative damage during RHDV infection. These findings may provide novel insights into the pathogenesis of RHDV.

Qualitative Assessment of Carbon Nanotube Toxicity to Mouse Liver using Dark‐field Microscopy

Broad use of nanomaterials may eventually lead to environmental poisoning, including the contamination of food. However, methods for the assessment of nanomaterial toxicity are not well developed. The goal of the current study was to develop a techniques to measure toxicity of multiwall carbon nanotubes (MWCNTs) in vivo. For this, male CD‐1 mice were fed by oral gavage with a water suspension of MWCNTs at varying doses up to 10 mg/kg/day. Twenty‐four hours later, blood chemistry testing showed elevation of aspartate aminotransferase (AST), a liver injury marker, at the highest used dose. The liver damage was confirmed by the terminal deoxynucleotidyl transferase dUTP nick‐end labeling (TUNEL) assay. Our further analysis included the application of dark‐field microscopy (DFM) for (a) the colocalization between MWCNTs and TUNEL‐positive cells and (b) development of a method to quantify MWCNTs burden in liver tissue. DFM clearly showed some elevation of particulate material in the liver with occasional association with TUNEL‐positive cells. DFM did not seem to allow precise quantification of nanoparticle aggregates due to low sensitivity of DFM at the concentration observed in the liver. However, we discovered that CNT gavage increased the percentage of nuclei colocalized with DF objects by systematically counting the number of liver cell nuclei in contact with dark‐field (DF) objects. TUNEL‐positive nuclei were photographed, analyzed at 100‐fold magnification and sorted by CNT treatment category. The process was repeated for DAPI nuclei to serve as a control. The percentage of nuclei with DF colocalization was recorded per group. Our results indicate that the rate of colocalization between dark‐field objects and nuclei appears to correlate directly with CNT‐gavage treatment. Another important observation, confirmed by an electron microscopy, was that there were many alive TUNEL‐negative cells containing MWCNTs. Overall, our data indicate that the DFM method designed for particle toxicology has only limited potential for measurement of nanoparticle toxicity, and that some mouse liver cells are capable of accumulating MWCNTs without inducing immediate cell death.Support or Funding InformationUAMS/ASPET Pharmacology/Toxicology Summer SURF Program USDA subcontract (Basnakian, PI) VA Merit Review grant (Basnakian, PI) COBRE grant (Hauer‐Jensen, PI)To study the effect of carbon nanotube (CNT) ingestion on mouse liver, we systematically counted the number of liver cell nuclei in contact with dark‐field (DF) objects. We found that CNT gavage increased the percentage of nuclei colocalized with DF objects at 100x. Of a total of 38 TUNEL cells recorded in gavage tissue, 22 were touching a DF‐positive object. Livers were extracted from male CD‐1 mice 72 hours after receiving a CNT gavage of 10mg CNT/kg mouse weight.Figure 1

Advances in the detection and clearance of hepatitis B virus covalently closed circular DNA (cccDNA)

Chronic hepatitis B (CHB) is a worldwide public health problem and current therapeutic drugs cannot completely eliminate the covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) in the liver cell nucleus. The presence of cccDNA leads to the persistent HBV infection, which is hard to be completely eliminated. At present, the research on cccDNA is getting increasing attention. Only by comprehensively understanding it can we find a better way to cure HBV infection. This article reviewed the structure, regulation, detection and elimination of HBV cccDNA. Key words: HBV; cccDNA; Detection; Elimination

Remedial effects of casticin as an antioxidant on cisplatin induced oxidative damage in rat liver

Cisplatin (CP) is an active cytotoxic agent, which has been verified to be effective in multiple cancer regimen. In this study, potential antioxidant effects of casticin (CAS) were assessed against CP generated oxidative stress in rat liver. “Twenty-four male Sprague Dawley rats were divided into four experimental groups. Group-1 (control group) received only normal saline”. Group-2 was intraperitoneally injected with CP (10 mg/kg). Group-3 was orally provided by CAS (50 mg/kg) along with CP (10 mg/kg) injection at first day. Group-4 group was orally administered with CAS (50 mg/kg) throughout the experiment. The rats of group-1 indicated “increase in serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP), while a significant decrease in the activities of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD)” was noticed, which revealed that CP generated oxidative stress in rat liver. Moreover, administration of CP increased the hydrogen peroxide (H2O2) concentration and level of “thiobarbituric acid reactive substances (TBARS)”, while reducing the % DNA head and head length in liver cell nuclei. CP disturbs the lobular structure of the liver and increased the sinusoidal dilation in rat liver. However, co-treatment with CAS successfully mitigated the CP generated DNA disruption, biochemical and pathological changes in rat liver. These findings revealed that an effective antioxidant, CAS, alleviated the CP generated hepatotoxicity and oxidative stress in rats.

The application of serum HBV RNA detection in anti-HBV treatment

The persistence of covalently closed circular DNA (cccDNA) in the nucleus of liver cells is a key factor that hinders the cure of chronic hepatitis B. However, it is difficult to eliminate cccDNA with existing anti-HBV therapy. Recent studies have found that serum HBV RNA may be a new indicator reflecting the activity of cccDNA in hepatocytes and evaluating the clinical efficacy of CHB patients. This article reviews recent advances in the properties, detection methods, and clinical significance of HBV RNA, particularly the application of antiviral therapy in CHB patients. Key words: Hepatitis B, chronic; Hepatitis B virus; RNA, viral; DNA, circular; Nucleosides; Interferon-alpha; Polyethylene glycols