-
Journal of Biomedical Materials... Apr 2016Whole organ engineering and cell-based regenerative medicine approaches are being investigated as potential therapeutic options for end-stage liver failure. However, a...
Whole organ engineering and cell-based regenerative medicine approaches are being investigated as potential therapeutic options for end-stage liver failure. However, a major challenge of these strategies is the loss of hepatic specific function after hepatocytes are removed from their native microenvironment. The objective of the present study was to determine if solubilized liver extracellular matrix (ECM), when used as a media supplement, can better maintain hepatocyte phenotype compared to type I collagen alone or solubilized ECM harvested from a non-liver tissue source. Liver extracellular matrix (LECM) from four different species was isolated via liver tissue decellularization, solubilized, and then used as a media supplement for primary rat hepatocytes (PRH). The four species of LECM investigated were human, porcine, canine and rat. Cell morphology, albumin secretion, and ammonia metabolism were used to assess maintenance of hepatocyte phenotype. Biochemical and mechanical characterization of each LECM were also conducted. Results showed that PRH's supplemented with canine and porcine LECM maintained their phenotype to a greater extent compared to all other groups. PRH's supplemented with canine and porcine LECM showed increased bile production, increased albumin production, and the formation of multinucleate cells. The findings of the present study suggest that solubilized liver ECM can support in-vitro hepatocyte culture and should be considered for therapeutic and diagnostic techniques that utilize hepatocytes.
Topics: Animals; Cell Culture Techniques; Cells, Cultured; Collagen Type I; Culture Media; Dogs; Extracellular Matrix; Hepatocytes; Humans; Hydrogels; Liver; Rats; Rats, Sprague-Dawley; Rheology; Solubility; Swine
PubMed: 26704367
DOI: 10.1002/jbm.a.35636 -
Journal of Applied Toxicology : JAT Jun 2016Sustained activation of the aryl hydrocarbon receptor (AHR) is believed to be the initial key event in AHR receptor-mediated tumorigenesis in the rat liver. The role of...
Sustained activation of the aryl hydrocarbon receptor (AHR) is believed to be the initial key event in AHR receptor-mediated tumorigenesis in the rat liver. The role of AHR in mediating pathological changes in the liver prior to tumor formation was investigated in a 4-week, repeated-dose study using adult female wild-type (WT) and AHR knockout (AHR-KO) rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Beginning at 8 weeks of age, AHR-KO and WT rats were dosed by oral gavage with varying concentrations of TCDD (0, 3, 22, 100, 300 and 1000 ng kg(-1) day(-1) ). Lung, liver and thymus histopathology, hematology, serum chemistry and the distribution of TCDD in liver and adipose tissue were examined. Treatment-related increases in the severity of liver and thymus pathology were observed in WT, but not AHR-KO rats. In the liver, these included hepatocellular hypertrophy, bile duct hyperplasia, multinucleated hepatocytes and inflammatory cell foci. A loss of cellularity in the thymic cortex and thymic atrophy was observed. Treatment-related changes in serum chemistry parameters were also observed in WT, but not AHR-KO rats. Finally, dose-dependent accumulation of TCDD was observed primarily in the liver of WT rats and primarily in the adipose tissue of AHR-KO rats. The results suggest that AHR activation is the initial key event underlying the progression of histological effects leading to liver tumorigenesis following TCDD treatment. Copyright © 2015 John Wiley & Sons, Ltd.
Topics: Adipose Tissue; Administration, Oral; Animals; Basic Helix-Loop-Helix Transcription Factors; Carcinogenesis; Dose-Response Relationship, Drug; Environmental Pollutants; Female; Gene Knockout Techniques; Hyperplasia; Hypertrophy; Liver; Lung; Polychlorinated Dibenzodioxins; Precancerous Conditions; Random Allocation; Rats, Sprague-Dawley; Rats, Transgenic; Receptors, Aryl Hydrocarbon; Teratogens; Thymus Gland; Tissue Distribution; Toxicokinetics
PubMed: 26278112
DOI: 10.1002/jat.3211 -
Military Medicine May 2015Giant cell hepatitis is a rare entity in adults, accounting for 0.1% to 0.25% of liver disease in adults. Postinfantile giant cell hepatitis is often characterized by...
BACKGROUND
Giant cell hepatitis is a rare entity in adults, accounting for 0.1% to 0.25% of liver disease in adults. Postinfantile giant cell hepatitis is often characterized by multinucleated giant cells on liver biopsy and a fulminant hepatitis.
CASE REPORT
An active duty 36-year-old African-American male deployed to Kabul, Afghanistan, presented with jaundice 2 weeks after starting a testosterone analogue. He discontinued the supplement, but his jaundice persisted with up-trending bilirubin. Serologic testing was negative for hepatitis A, B, C, and E; cytomegalovirus; Epstein-Barr virus; herpes simplex virus; and human immunodeficiency virus. Evaluation for autoimmune hepatitis was negative. Magnetic resonance cholangiopancreatography was negative for obstruction. Liver biopsy revealed giant cell transformation of numerous hepatocytes and cholestatic hepatitis. Rapid plasma reagin was positive without physical findings. Treponema pallidum hemagglutination assays confirmed the diagnosis of latent syphilis. He was started on penicillin treatment with rapid improvement of bilirubin, creatinine, and hepatic synthetic function, all of which eventually normalized.
CONCLUSION
Postinfantile giant cell hepatitis is a severe form of hepatitis that has several different potential etiologies, 2 of which were present in this patient: androgenic supplements and infection. This case highlights syphilis as an unusual but treatable cause of giant cell hepatitis. Testing for syphilis should be considered in any persistent liver injury.
Topics: Adult; Giant Cells; Hepatitis; Humans; Male; Military Personnel; Syphilis, Latent; United States
PubMed: 25939121
DOI: 10.7205/MILMED-D-14-00530 -
The Journal of Pathology Jul 2015Although hepatitis B virus (HBV) has been established to cause hepatocellular carcinoma (HCC), the exact mechanism remains to be clarified. Type II ground glass...
Although hepatitis B virus (HBV) has been established to cause hepatocellular carcinoma (HCC), the exact mechanism remains to be clarified. Type II ground glass hepatocytes (GGHs) harbouring the HBV pre-S2 mutant large surface protein (LHBS) have been recognized as a morphologically distinct hallmark of HCC in the advanced stages of chronic HBV infection. Considering its preneoplastic nature, we hypothesized that type II GGH may exhibit high genomic instability, which is important for the carcinogenic process in chronic HBV carriers. In this study we found that pre-S2 mutant LHBS directly interacted with importin α1, the key factor that recognizes cargos undergoing nuclear transportation mediated by the importin α/β-associated nuclear pore complex (NPC). By interacting with importin α1, which inhibits its function as an NPC factor, pre-S2 mutant LHBS blocked nuclear transport of an essential DNA repair and recombination factor, Nijmegen breakage syndrome 1 (NBS1), upon DNA damage, thereby delaying the formation of nuclear foci at the sites of DNA double-strand breaks (DSBs). Pre-S2 mutant LHBS was also found to block NBS1-mediated homologous recombination repair and induce multi-nucleation of cells. In addition, pre-S2 mutant LHBS transgenic mice showed genomic instability, indicated by increased global gene copy number variations (CNVs), which were significantly higher than those in hepatitis B virus X mice, indicating that pre-S2 mutant LHBS is the major viral oncoprotein inducing genomic instability in HBV-infected hepatocytes. Consistently, the human type II GGHs in HCC patients exhibited increased DNA DSBs representing significant genomic instability. In conclusion, type II GGHs harbouring HBV pre-S2 mutant oncoprotein represent a high-risk marker for the loss of genome integrity in chronic HBV carriers and explain the complex chromosome changes in HCCs. Mouse array CGH raw data: GEO Accession No. GSE61378 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE61378).
Topics: Animals; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Transformation, Viral; Comparative Genomic Hybridization; DNA Breaks, Double-Stranded; DNA Copy Number Variations; DNA Damage; DNA Repair; Female; Genomic Instability; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis B, Chronic; Hepatocytes; Humans; Liver Neoplasms; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Protein Precursors; Viral Envelope Proteins
PubMed: 25775999
DOI: 10.1002/path.4531 -
Biomedicines Feb 2015Activation of the hepatocyte growth factor/Met receptor is involved in muscle regeneration, through promotion of proliferation and inhibition of differentiation in...
Activation of the hepatocyte growth factor/Met receptor is involved in muscle regeneration, through promotion of proliferation and inhibition of differentiation in myogenic stem cells (MSCs). We previously described that the specific expression of an oncogenic version of the Met receptor (Tpr-Met) in terminally-differentiated skeletal muscle causes muscle wasting . Here, we induced Tpr-Met in differentiated myotube cultures derived from the transgenic mouse. These cultures showed a reduced protein level of myosin heavy chain (MyHC), increased phosphorylation of Erk1,2 MAPK, the formation of giant sacs of myonuclei and the collapse of elongated myotubes. Treatment of the cultures with an inhibitor of the MAPK kinase pathway or with an inhibitor of the proteasome increased the expression levels of MyHC. In addition, the inhibition of the MAPK kinase pathway prevented the formation of myosacs and myotube collapse. Finally, we showed that induction of Tpr-Met in primary myotubes was unable to produce endoreplication in their nuclei. In conclusion, our data indicate that multinucleated, fused myotubes may be forced to disassemble their contractile apparatus by the Tpr-Met oncogenic factor, but they resist the stimulus toward the reactivation of the cell cycle.
PubMed: 28536403
DOI: 10.3390/biomedicines3010124 -
Chemical Research in Toxicology Mar 2015The multinucleation effect of silica nanoparticles (SiNPs) had been determined in our previous studies, but the relative mechanisms of multinucleation and how the...
The multinucleation effect of silica nanoparticles (SiNPs) had been determined in our previous studies, but the relative mechanisms of multinucleation and how the multinucleated cells are generated were still not clear. This extensional study was conducted to investigate the mechanisms underlying the formation of multinucleated cells after SiNPs exposure. We first investigated cellular multinucleation, then performed time-lapse confocal imaging to certify whether the multinucleated cells resulted from cell fusion or abnormal cell division. Our results confirmed for the first time that there are three patterns contributing to the SiNPs-induced multinucleation in HepG2 cells: cell fusion, karyokinesis without cytokinesis, and cytokinesis followed by fusion. The chromosomal passenger complex (CPC) deficiency and cell cycle arrest in G1/S and G2/M checkpoints may be responsible for the cell aberrant cytokinesis. The activated MAPK/ERK1/2 signaling and decreased mitosis related proteins might be the underlying mechanism of cell cycle arrest and thus multinucleation. In summary, we confirmed the hypothesis that aberrant cytokinesis and cell fusion resulted in multinucleation in HepG2 cells after SiNPs exposure. Since cell fusion and multinucleation were involved in genetic instability and tumor development, this study suggests the potential ability of SiNPs to induce cellular genetic instability. These findings raise concerns with regard to human health hazards and environmental risks with SiNPs exposure.
Topics: Cell Fusion; Cell Nucleus Division; Cytokinesis; Hep G2 Cells; Humans; Microscopy, Electron, Transmission; Mitogen-Activated Protein Kinases; Nanoparticles; Silicon Dioxide
PubMed: 25625797
DOI: 10.1021/tx500473h -
Avian Diseases Dec 2014A broiler breeder flock was subcutaneously vaccinated at the hatchery with a live avian orthoreovirus (ARV) vaccine against viral arthritis. Chicks began to die at 3...
A broiler breeder flock was subcutaneously vaccinated at the hatchery with a live avian orthoreovirus (ARV) vaccine against viral arthritis. Chicks began to die at 3 days of age and postmortem examination revealed massive subcutaneous hemorrhages and edema on the dorsal aspect of the neck at the site of vaccination, a severe necrotic hepatitis, and pulmonary edema. Microscopically, the main lesion was a multifocal vacuolar degeneration and necrosis of randomly distributed small groups of hepatocytes with presence of apoptotic and multinucleated syncytial cells. Necrotic foci were also found in the lungs as well as a hemorrhagic, granulomatous, and heterophilic cellulitis and myositis of the neck and a generalized depletion and lymphocytolysis of lymphoid organs. At 8 days of age, birds also began to show hock swelling histologically characterized by a fibrinoleucocytic inflammation of the articulation and tendon sheaths, with hyperplasia of the synovial membrane, and lymphoplasmocytic infiltration. PCR and viral culture of livers were positive for ARV. Partial sequencing of the S1 gene from the virus isolate showed 99.2% to 99.8% homology with three vaccinal strains (ARV S1133, 1733, and 2408). Viral particles compatible with reovirus virions were observed at transmission electron microscopy. Investigation at the hatchery revealed that chicks were inadvertently administered an S1133 reovirus vaccine labeled for water administration in 10- to 17-week-old chickens. This human error is most likely the reason for this unusually severe viremic reovirus infection that affected this flock at such an early age.
Topics: Animals; Chickens; Female; Injections, Subcutaneous; Male; Medication Errors; Orthoreovirus, Avian; Reoviridae Infections; Viral Vaccines
PubMed: 25619015
DOI: 10.1637/10860-050914-Case.1 -
The Korean Journal of Parasitology Oct 2014This study reports the first case of Capillaria hepatica infection in a nutria in Korea. Ten nutrias, captured near the Nakdong River, were submitted to our laboratory...
This study reports the first case of Capillaria hepatica infection in a nutria in Korea. Ten nutrias, captured near the Nakdong River, were submitted to our laboratory for necropsy. White-yellowish nodules were found in the liver of 1 of the nutrias at necropsy. Histologically, the lesions were granulomatous, and infiltrations of lipid-laden macrophages, eosinophils, and several multinucleated giant cells were observed. The lesions consisted of numerous eggs and necrotic hepatocytes. The eggs were lemon-shaped and had polar plugs at the ends of both long sides. The eggs were morphologically identified as those of C. hepatica. Worldwide, C. hepatica infection in nutrias is very rare. Nutrias are a kind of livestock, as well as wildlife; therefore, an epidemiological study for parasitic infections needs to be conducted.
Topics: Animals; Capillaria; Enoplida Infections; Female; Male; Republic of Korea; Rodent Diseases; Rodentia
PubMed: 25352702
DOI: 10.3347/kjp.2014.52.5.527 -
Environmental Toxicology Apr 2016Microcystin-LR is a cyanobacterial toxin found in surface and recreational waters that inhibits protein phosphatases and may disrupt the cytoskeleton. Microcystins...
Microcystin-LR is a cyanobacterial toxin found in surface and recreational waters that inhibits protein phosphatases and may disrupt the cytoskeleton. Microcystins induce apoptosis in hepatocytes at ≤ 2.0 µM. Nothing is known about the effects of microcystins on human placental trophoblast differentiation and function. The differentiation of villous trophoblasts to form syncytiotrophoblast occurs throughout pregnancy and is essential for normal placental and fetal development. To investigate the effects of microcystin, villous cytotrophoblasts were isolated from term placentas using an established method and exposed to microcystin-LR. Microcystin-LR below the cytotoxic dose of 25 µM did not cause cell rounding or detachment, had no effect on apoptosis, and no effect on the morphological differentiation of mononucleated cytotrophoblasts to multinucleated syncytiotrophoblast. However, secretion of human chorionic gonadotropin (hCG) increased in a microcystin-LR dose-dependent manner. When incubated with l-buthionine sulphoximine (BSO) to deplete glutathione levels, trophoblast morphological differentiation proceeded normally in the presence of microcystin-LR. Microcystin-LR did not disrupt the trophoblast microtubule cytoskeleton, which is known to play a role in trophoblast differentiation. Immunofluorescence studies showed that trophoblasts express organic anion transport protein 1B3 (OATP1B3), a known microcystin transport protein. In comparison to hepatocytes, trophoblasts appear to be more resistant to the toxic effects of microcystin-LR. The physiological implications of increased hCG secretion in response to microcystin-LR exposure remain to be determined.
Topics: Apoptosis; Bacterial Toxins; Cell Differentiation; Cells, Cultured; Chorionic Gonadotropin; Female; Humans; Marine Toxins; Microcystins; Placenta; Pregnancy; Trophoblasts
PubMed: 25346179
DOI: 10.1002/tox.22056 -
BMC Gastroenterology Jul 2014Staphylococcus epidermidis is the most frequently isolated species of the coagulase negative staphylococci from human stool. However, it is not clear how its presence in...
BACKGROUND
Staphylococcus epidermidis is the most frequently isolated species of the coagulase negative staphylococci from human stool. However, it is not clear how its presence in the gut affects the cellular structures and functions of this organ. In this study therefore, the pathogenicity of strains of S. epidermidis which were isolated from the stool samples of apparently healthy children was investigated in mice and rats.
METHODS
The albino mice (22-30 g) and albino rats (100-155 g) of both sexes were infected orally and intraperitoneally with graded doses of the bacteria and subjected to behavioral and histopathological examinations.
RESULTS
Acute infection in these animals caused temporary behavioural changes as shown by restlessness and abdominal stretchings but did not result in death even at a dosage of 2 × 109 cfu/kg. Daily administration of the same dose for 14 days resulted in the death of 11 out of 21 (52.4%) mice. Histopathological examination of the affected organs showed congestions, aggregations and multinucleated hepatocytes in the liver, infiltration of the kidney tubule interstitial by chronic inflammatory cells, coagulative necrosis of the kidney, spleen, intestine and stomach cells as well as marked stroma fibrosis of the spleen. Coagulative necrosis of cells was the most frequently occurring pathological alteration. Lethality and pathological effects reflected the virulence factors expressed by the organism which are biofilm formation, haemagglutination properties and capsule production.
CONCLUSIONS
The results indicate that strains of S. epidermidis colonising the gut can cause serious pathological changes on certain organs such as kidney, liver, intestine, stomach and spleen which, depending on their severity, could be fatal.
Topics: Animals; Behavior, Animal; Female; Gastrointestinal Tract; Humans; Kidney; Liver; Male; Mice; Rats; Spleen; Staphylococcal Infections; Staphylococcus epidermidis; Virulence
PubMed: 25016472
DOI: 10.1186/1471-230X-14-126