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1.
Antioxidants (Basel) ; 12(3)2023 Mar 10.
Article in English | MEDLINE | ID: mdl-36978930

ABSTRACT

Cancer cells adjust their metabolism to meet energy demands. In particular, glutamine addiction represents a distinctive feature of several types of tumors, including colorectal cancer. In this study, four colorectal cancer cell lines (Caco-2, HCT116, HT29 and SW480) were cultured with or without glutamine. The growth and proliferation rate, colony-forming capacity, apoptosis, cell cycle, redox homeostasis and metabolomic analysis were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test (MTT), flow cytometry, high-performance liquid chromatography and gas chromatography/mass spectrometry techniques. The results show that glutamine represents an important metabolite for cell growth and that its deprivation reduces the proliferation of colorectal cancer cells. Glutamine depletion induces cell death and cell cycle arrest in the GO/G1 phase by modulating energy metabolism, the amino acid content and antioxidant defenses. Moreover, the combined glutamine starvation with the glycolysis inhibitor 2-deoxy-D-glucose exerted a stronger cytotoxic effect. This study offers a strong rationale for targeting glutamine metabolism alone or in combination with glucose metabolism to achieve a therapeutic benefit in the treatment of colon cancer.

2.
Clin Exp Med ; 23(4): 1251-1263, 2023 Aug.
Article in English | MEDLINE | ID: mdl-36459278

ABSTRACT

Microbial secondary infections can contribute to an increase in the risk of mortality in COVID-19 patients, particularly in case of severe diseases. In this study, we collected and evaluated the clinical, laboratory and microbiological data of COVID-19 critical ill patients requiring intensive care (ICU) to evaluate the significance and the prognostic value of these parameters. One hundred seventy-eight ICU patients with severe COVID-19, hospitalized at the S. Francesco Hospital of Nuoro (Italy) in the period from March 2020 to May 2021, were enrolled in this study. Clinical data and microbiological results were collected. Blood chemistry parameters, relative to three different time points, were analyzed through multivariate and univariate statistical approaches. Seventy-four percent of the ICU COVID-19 patients had a negative outcome, while 26% had a favorable prognosis. A correlation between the laboratory parameters and days of hospitalization of the patients was observed with significant differences between the two groups. Moreover, Staphylococcus aureus, Enterococcus faecalis, Candida spp, Pseudomonas aeruginosa and Klebsiella pneumoniae were the most frequently isolated microorganisms from all clinical specimens. Secondary infections play an important role in the clinical outcome. The analysis of the blood chemistry tests was found useful in monitoring the progression of COVID-19.


Subject(s)
COVID-19 , Coinfection , Humans , SARS-CoV-2 , Pandemics , Intensive Care Units
3.
Inflamm Regen ; 42(1): 59, 2022 Dec 05.
Article in English | MEDLINE | ID: mdl-36471376

ABSTRACT

Although the signaling pathways involved in normal liver regeneration have been well characterized, less has been done for livers affected by chronic tissue damage. These "abnormal livers" have an impaired regenerative response that leads to liver repair and fibrosis. The tumor suppressor Hippo pathway plays a key role in liver regeneration and repair. On this basis, this review discusses recent studies focusing on the involvement of the Hippo signaling pathway during "normal healthy liver regeneration" (i.e., in a normal liver after 2/3 partial hepatectomy) and "abnormal liver regeneration" (i.e., in a liver damaged by chronic disease). This could be an important question to address with respect to new therapies aimed at improving impaired liver regenerative responses. The studies reported here have shown that activation of the Hippo coactivators YAP/TAZ during normal liver regeneration promotes the formation of a new bile duct network through direct BEC proliferation or/and hepatocyte dedifferentiation to HPCs which can trans-differentiate to BECs. Moreover, YAP/TAZ signaling interaction with other signaling pathways mediates the recruitment and activation of Kupffer cells, which release mitogenic cytokines for parenchymal and/or non-parenchymal cells and engage in phagocytosis of cellular debris. In addition, YAP-mediated activation of stellate cells (HSCs) promotes liver regeneration through the synthesis of extracellular matrix. However, in chronically diseased livers, where the predetermined threshold for proper liver regeneration is exceeded, YAP/TAZ activation results in a reparative process characterized by liver fibrosis. In this condition, YAP/TAZ activation in parenchymal and non-parenchymal cells results in (i) differentiation of quiescent HSCs into myofibroblastic HSCs; (ii) recruitment of macrophages releasing inflammatory cytokines; (iii) polarization of macrophages toward the M2 phenotype. Since accumulation of damaged hepatocytes in chronic liver injury represent a significant risk factor for the development of hepatocarcinoma, this review also discussed the involvement of the Hippo pathway in the clearance of damaged cells.

4.
Sci Rep ; 10(1): 7139, 2020 04 28.
Article in English | MEDLINE | ID: mdl-32345994

ABSTRACT

Hepatocellular carcinoma (HCC) is the most common liver cancer and a major cause of adult death. The current treatments for HCC suffer from drug resistance and poor prognosis; therefore, novel therapeutic agents are urgently needed. Phytochemicals have been proposed to treat a range of cancers. Among them, α-lipoic acid (α-LA), a naturally synthesized antioxidant found in various dietary animal and plant sources, prevents oxidant-mediated cell death in normal cells while inducing apoptosis in several cancer cell lines. Previously, we demonstrated that the treatment of hepatoma cells with α-LA induced apoptosis, which was preceded by the generation of reactive oxygen species (ROS) and activation of the p53 protein, a known inducer of mitochondria-mediated apoptosis. Several studies have shown that ROS-induced apoptosis is associated with endoplasmic reticulum (ER) stress and Unfolded Protein Response (UPR) activation. Herein, we investigated if α-LA-induced apoptosis in hepatoma cell lines was ER stress- and UPR-mediated by gene expression profiling analyses. UPR and ER stress pathways were the most up-regulated after treatment with α-LA. This finding, which has been confirmed by expression analyses of ER- and UPR-associated proteins, provides a better understanding of the molecular mechanisms behind the anti-tumoral action of α-LA on hepatoma cells.


Subject(s)
Apoptosis/drug effects , Endoplasmic Reticulum Stress/drug effects , Liver Neoplasms, Experimental/pathology , Thioctic Acid/pharmacology , Animals , Cell Line, Tumor , Gene Expression Profiling , Liver Neoplasms, Experimental/genetics , Liver Neoplasms, Experimental/metabolism , Rats , Reactive Oxygen Species/metabolism , Unfolded Protein Response/drug effects
5.
Br J Pharmacol ; 175(16): 3298-3314, 2018 08.
Article in English | MEDLINE | ID: mdl-29570770

ABSTRACT

BACKGROUND AND PURPOSE: Microglial phenotype and phagocytic activity are deregulated in Parkinson's disease (PD). PPARγ agonists are neuroprotective in experimental PD, but their role in regulating microglial phenotype and phagocytosis has been poorly investigated. We addressed it by using the PPARγ agonist MDG548. EXPERIMENTAL APPROACH: Murine microglial cell line MMGT12 was stimulated with LPS and/or MDG548, and their effect on phagocytosis of fluorescent microspheres or necrotic neurons was investigated by flow cytometry. Cytokines and markers of microglia phenotype, such as mannose receptor C type 1; MRC1), Ym1 and CD68 were measured by elisa and fluorescent immunohistochemistry. Levels of Beclin-1, which plays a role in microglial phagocytosis, were measured by Western blotting. In the in vivo MPTP-probenecid (MPTPp) model of PD in mice, MDG548 was tested on motor impairment, nigral neurodegeneration, microglial activation and phenotype. KEY RESULTS: In LPS-stimulated microglia, MDG548 increased phagocytosis of both latex beads and necrotic cells, up-regulated the expression of MRC1, CD68 and to a lesser extent IL-10, while blocking the LPS-induced increase of TNF-α and iNOS. MDG548 also induced Beclin-1. Chronic MPTPp treatment in mice down-regulated MRC1 and TGF-ß and up-regulated TNF-α and IL-1ß immunoreactivity in activated CD11b-positive microglia, causing the death of nigral dopaminergic neurons. MDG548 arrested MPTPp-induced cell death, enhanced MRC1 and restored cytokine levels. CONCLUSIONS AND IMPLICATIONS: This study adds a novel mechanism for PPARγ-mediated neuroprotection in PD and suggests that increasing phagocytic activity and anti-inflammatory markers may represent an effective disease-modifying approach.


Subject(s)
Microglia/drug effects , Neuroprotection/physiology , PPAR gamma/agonists , Parkinsonian Disorders/metabolism , Phagocytosis/drug effects , Thiobarbiturates/pharmacology , Animals , Cell Line , Cytokines/metabolism , Disease Models, Animal , Humans , Lipopolysaccharides/pharmacology , Male , Mice, Inbred C57BL , Microglia/physiology , Microspheres , PPAR gamma/metabolism , Phenotype
6.
Int J Pharm ; 537(1-2): 257-267, 2018 Feb 15.
Article in English | MEDLINE | ID: mdl-29294323

ABSTRACT

Triiodothyronine (T3), a thyroid hormone synthesized and secreted by the thyroid gland, plays an essential role in morphogenesis and differentiation through interaction with its nuclear receptors (TRs). However, there are increasing evidences for its role in hepatocellular carcinoma (HCC) suppression. The aim of this work was to develop an effective hepatocellular carcinoma targeting drug delivery system to improve T3 delivery to hepatic cancer cells as well as to reduce toxic side effects. Three different liposomal systems, such as unmodified, Stealth (PEGylated) and Lactoferrin (Lf)-modified-Stealth liposomes were successfully prepared by the film hydration method, and fully characterized. Liposome cell interactions and cellular uptake were evaluated in three different HCC target cells (FaO, HepG2 and SKHep) by confocal microscopy. Finally, in vitro cytotoxicity studies were carried out by using MTT assay to evaluate toxicity of the liposome delivery system and to test the effect of T3 when incorporated into liposomes. Internalization studies, performed using Lf-modified-liposomes labeled with the lipophilic marker Rho-PE and loaded with the hydrophilic probe CF, clearly demonstrated the effective internalization of both hydrophilic and lipophilic markers. Lf-liposomes might markedly enhance the specific cell binding and cellular uptake in hepatoma cells due to the mediating of Lf that could bind with high affinity to multiple receptors on cell surface, such as ASGP-R. Results obtained from this study highlight that the Lf- modified-liposomal delivery system may ensure a specific and sustained T3 delivery, thus, allowing reduced therapeutic doses and deleterious side effects of T3.


Subject(s)
Carcinoma, Hepatocellular/drug therapy , Lactoferrin/chemistry , Liposomes/chemistry , Liver Neoplasms/drug therapy , Triiodothyronine/administration & dosage , Triiodothyronine/chemistry , Animals , Asialoglycoprotein Receptor/metabolism , Carcinoma, Hepatocellular/metabolism , Cell Line, Tumor , Delayed-Action Preparations/administration & dosage , Delayed-Action Preparations/chemistry , Drug Delivery Systems/methods , Hep G2 Cells , Humans , Liver Neoplasms/metabolism , Polyethylene Glycols/chemistry , Rats
7.
Molecules ; 22(10)2017 Oct 17.
Article in English | MEDLINE | ID: mdl-29039799

ABSTRACT

New 1-[1-(1H-indol-3-yl) alkyl]-1H-indoles, surprisingly, have been obtained from the addition of indole to a variety of aldehydes under neat conditions. CaO, present in excess, was fundamental for carrying out the reaction with paraformaldehyde. Under the same reaction conditions, aromatic and heteroaromatic aldehydes afforded only classical bis (indolyl) aryl indoles. In this paper, the role of CaO, together with the regiochemistry and the mechanism of the reaction, are discussed in detail. The effect of some selected 3,3'- and 1,3'-diindolyl methane derivatives on cell proliferation of the hepatoma cell line FaO was also evaluated.


Subject(s)
Aldehydes/chemistry , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Indoles/chemical synthesis , Indoles/pharmacology , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Gas Chromatography-Mass Spectrometry , Humans , Indoles/chemistry , Liver Neoplasms , Magnetic Resonance Spectroscopy , Molecular Structure , Solvents
8.
Exp Neurol ; 286: 83-92, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27697481

ABSTRACT

Neuroinflammation is associated with l-DOPA treatment in Parkinson's disease (PD), suggesting a role in l-DOPA-induced dyskinesia (LID), however it is unclear whether increased inflammation is specifically related to the dyskinetic outcome of l-DOPA treatment. Diversely from oral l-DOPA, continuous intrajejunal l-DOPA infusion is associated with very low dyskinetic outcome in PD patients. We reproduced these regimens of administration in 6-OHDA-lesioned hemiparkinsonian rats, where dyskinetic responses and striatal neuroinflammation induced by chronic pulsatile (DOPAp) or continuous (DOPAc) l-DOPA were compared. Moreover, we investigated the contribution of a peripheral inflammatory challenge with lipopolysaccharide (LPS), to DOPAp-induced dyskinetic and neuroinflammatory responses. Rats 6-OHDA-infused in the medial forebrain bundle received two weeks treatment with DOPAp, DOPAc via subcutaneous osmotic minipumps, or DOPAp followed by DOPAc. l-DOPA plasma levels were measured in all experimental groups. An independent group of rats received one peripheral dose of LPS 24h before DOPAp treatment. Abnormal involuntary movements (AIMs) were evaluated as a rat model of LID. Immunoreactivity (IR) for OX-42, microglial and neuronal TNF-α, iNOS and GFAP was quantified in denervated and contralateral striatum. In addition, serum TNF-α was measured. The 6-OHDA denervation induced a mild microgliosis in the striatum two weeks after neurotoxin infusion, and increased TNF-α IR in microglia. Rats receiving the DOPAp treatment developed AIMs and displayed increased striatal OX-42, microglial TNF-α, iNOS and GFAP. Moreover, TNF-α IR was also increased in a subpopulation of striatal neurons. Conversely, DOPAc did not induce AIMs or inflammatory responses in either drug-naïve animals or rats that were previously dyskinetic when exposed to DOPAp. Serum TNF-α was not altered by any l-DOPA treatment. LPS pre-treatment increased the degree of DOPAp-induced AIMs and striatal IR for OX-42, TNF-α, iNOS and GFAP. Altogether the present findings indicate that in the 6-OHDA model, chronic l-DOPA induces striatal inflammatory responses, which however depend upon the administration regimen and the dyskinetic outcome of drug treatment. The potentiation of dyskinetic responses by LPS suggests a reciprocal causal link between neuroinflammation and LID.


Subject(s)
Antiparkinson Agents/adverse effects , Dyskinesia, Drug-Induced/etiology , Encephalitis/chemically induced , Levodopa/adverse effects , Parkinson Disease/drug therapy , Animals , Antiparkinson Agents/administration & dosage , Antiparkinson Agents/blood , Corpus Striatum/drug effects , Corpus Striatum/metabolism , Cytokines/metabolism , Disease Models, Animal , Drug Delivery Systems/adverse effects , Functional Laterality/drug effects , Gene Expression Regulation/drug effects , Levodopa/administration & dosage , Levodopa/blood , Lipopolysaccharides/pharmacology , Male , Nerve Tissue Proteins/metabolism , Oxidopamine/toxicity , Parkinson Disease/blood , Parkinson Disease/etiology , Parkinson Disease/pathology , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Sympatholytics/toxicity , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
9.
Neurobiol Dis ; 71: 280-91, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25134730

ABSTRACT

Neuroinflammatory changes play a pivotal role in the progression of Parkinson's disease (PD) pathogenesis. Recent findings have suggested that activated microglia may polarize similarly to peripheral macrophages in the central nervous system (CNS), assuming a pro-inflammatory M1 phenotype or the alternative anti-inflammatory M2 phenotype via cytokine production. A skewed M1 activation over M2 has been related to disease progression in Alzheimer disease, and modulation of microglia polarization may be a therapeutic target for neuroprotection. By using the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-probenecid (MPTPp) mouse model of progressive PD, we investigated dynamic changes in the production of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-1ß, and anti-inflammatory cytokines, such as transforming growth factor (TGF)-ß and IL-10, within Iba-1-positive cells in the substantia nigra compacta (SNc). In addition, to further characterize changes in the M2 phenotype, we measured CD206 in microglia. Moreover, in order to target microglia polarization, we evaluated the effect of the peroxisome-proliferator-activated receptor (PPAR)-γ agonist rosiglitazone, which has been shown to exert neuroprotective effects on nigral dopaminergic neurons in PD models, and acts as a modulator of cytokine production and phenotype in peripheral macrophages. Chronic treatment with MPTPp induced a progressive degeneration of SNc neurons. The neurotoxin treatment was associated with a gradual increase in both TNF-α and IL-1ß colocalization with Iba-1-positive cells, suggesting an increase in pro-inflammatory microglia. In contrast, TGF-ß colocalization was reduced by the neurotoxin treatment, while IL-10 was mostly unchanged. Administration of rosiglitazone during the full duration of MPTPp treatment reverted both TNF-α and IL-1ß colocalization with Iba-1 to control levels. Moreover, rosiglitazone induced an increase in TGF-ß and IL-10 colocalization compared with the MPTPp treatment. CD206 was gradually reduced by the chronic MPTPp treatment, while rosiglitazone restored control levels, suggesting that M2 anti-inflammatory microglia were stimulated and inflammatory microglia were inhibited by the neuroprotective treatment. The results show that the dopaminergic degeneration was associated with a gradual microglia polarization to the inflammatory over the anti-inflammatory phenotype in a chronic mouse model of PD. Neuroprotective treatment with rosiglitazone modulated microglia polarization, boosting the M2 over the pro-inflammatory phenotype. PPAR-γ agonists may offer a novel approach to neuroprotection, acting as disease-modifying drugs through an immunomodulatory action in the CNS.


Subject(s)
Cytokines/metabolism , MPTP Poisoning/drug therapy , MPTP Poisoning/pathology , Microglia/drug effects , Neuroprotective Agents/therapeutic use , Thiazolidinediones/therapeutic use , Animals , Cell Count , Cell Polarity/drug effects , Cytokines/genetics , Disease Models, Animal , Gene Expression Regulation/drug effects , MPTP Poisoning/metabolism , Mice , Microglia/classification , Microglia/metabolism , Nerve Degeneration/etiology , Nerve Degeneration/prevention & control , Neuroprotective Agents/pharmacology , RNA, Messenger/metabolism , Rosiglitazone , Thiazolidinediones/pharmacology , Tyrosine 3-Monooxygenase/metabolism
10.
J Endod ; 40(1): 124-8, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24332003

ABSTRACT

OBJECTIVE: This study evaluated the cytotoxicity of the new experimental self-adhesive, methachrylate-based hybrid root canal sealer XT and compared it with the epoxy resin-based AH Plus Jet. METHODS: The cytotoxicity of the tested materials was evaluated after 1, 24, 48, and 72 hours by using growing and confluent mouse fibroblast cell line L929. L929 fibroblasts were maintained in Dulbecco modified medium containing 10% fetal calf serum at 37°C and 5% CO2. At confluence, cells were seeded in 24-well plates at concentration of 1.5 × 10(5) cells (growing cells) or 2.5 × 10(5) (confluent cells) for each well. An amount of 5 µL of each root sealer (mixed according to manufacturer's specifications) was placed into individual wells containing a monolayer of L929 cells to mimic the in vivo condition of the possible extrusion of sealer in the periapical tissues. Neutral Red and [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide] were used for the cytotoxicity evaluation. Untreated cells were used as control. Two-way analysis of variance with Bonferroni test was used to compare the toxicity of the 2 sealers; one-way analysis of variance with Tukey test was performed to compare the cytotoxicity of each sealer at any considered time points (P < .05). Results were confirmed by examination with optical microscope. RESULTS: Both sealers induced a time-dependent cell death of mouse fibroblast L929; however, XT was less cytotoxic than AH Plus Jet as indicated by viability and morphologic analyses, and its initial cytotoxicity decreased progressively over time. CONCLUSIONS: These data support the possible use of XT as an endodontic sealer.


Subject(s)
Composite Resins/toxicity , Epoxy Resins/toxicity , Fibroblasts/drug effects , Root Canal Filling Materials/toxicity , Animals , Cell Count , Cell Death/drug effects , Cell Line , Cell Proliferation/drug effects , Cell Shape/drug effects , Cell Survival/drug effects , Materials Testing , Methacrylates/toxicity , Mice , Neutral Red , Tetrazolium Salts , Thiazoles , Time Factors
11.
Arch Pharm (Weinheim) ; 345(3): 195-202, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22715502

ABSTRACT

A mild and versatile method for the synthesis of some novel indole-1-carbinols has been developed via one-pot reaction of indoles and paraformaldehyde in the presence of an excess of CaO, MgO, ZnO or TiO(2). The solvent-free reaction provided all the indole derivatives in moderate to good yields and short reaction times. Moreover, the effect of some selected indole-1-carbinols on cell proliferation of the hepatoma cell line FaO was evaluated.


Subject(s)
Antineoplastic Agents/chemical synthesis , Indoles/chemical synthesis , Methanol/chemical synthesis , Animals , Antineoplastic Agents/pharmacology , Carcinoma, Hepatocellular/drug therapy , Cell Proliferation/drug effects , Indoles/pharmacology , Liver Neoplasms/drug therapy , Methanol/pharmacology , Rats , Tumor Cells, Cultured
12.
J Endod ; 36(9): 1516-20, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20728719

ABSTRACT

INTRODUCTION: Tetraacetylethylenediamine in association with sodium perborate (TAED+P) can be suggested for its use as an endodontic disinfectant because of its antimicrobial activity against different bacterial species when used at low concentrations. The purpose of this study was to measure the cytotoxicity of TAED+P on L929 fibroblasts and to compare it with that of sodium hypochlorite (NaOCl). METHODS: L929 fibroblasts were grown in Dulbecco Modified Eagle Medium containing 10% fetal calf serum (FCS) at 37 degrees C and 5% CO(2). At confluence, cells were split, plated in a 96-well plate, and incubated for 24 hours to allow attachment. The two disinfectants TAED+P and NaOCl were tested at various concentrations. The neutral red uptake and the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assays were used to evaluate the cell viability. The 50% inhibitory dose values for both disinfectants were calculated and statistically analyzed. The effect of both disinfectants on fibroblast viability was also determined in the presence of various concentrations of FCS. One-way analysis of variance with post hoc analysis using Tukey multiple comparison test was used for parametric data. RESULTS: Both disinfectants induced a dose-related loss of cell viability; TAED+P resulted less cytotoxic than NaOCl in all the examined experimental conditions. CONCLUSIONS: These data support the possible use of TAED+P as an endodontic irrigant. Further studies are required to analyze its antibacterial activity against endodontic pathogens.


Subject(s)
Borates/toxicity , Dental Disinfectants/toxicity , Ethylenediamines/toxicity , Fibroblasts/drug effects , Root Canal Irrigants/toxicity , Analysis of Variance , Animals , Cell Line , Cell Survival/drug effects , Dose-Response Relationship, Drug , Drug Combinations , Mice , Sodium Hypochlorite/pharmacology
13.
FASEB J ; 22(8): 2981-9, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18434432

ABSTRACT

Nonalcoholic fatty liver disease is the most common noninfectious liver disease in clinical practice, and there is an increasing need for new therapeutic approaches for the treatment of this liver disease. Here, we examined the effect of the thyroid hormone triiodothyronine (T3) and the agonist of the thyroid hormone receptor beta isoform (TRbeta), GC-1, on fatty liver and steatohepatitis induced in rodents by a choline-methionine deficient (CMD) diet. Male Fischer 344 rats fed a CMD diet for 1 wk developed a marked fatty liver and mild hepatitis. Concurrent administration of T3 resulted in a complete prevention of the fatty change associated with increased fatty acid mitochondrial and peroxisomal beta-oxidation. To investigate whether T3 could also reverse fully established fatty liver, rats were fed a CMD diet for 10 wk and then cofed T3 for 1 wk. Coadministration of T3 resulted in a complete regression of liver steatosis associated with a decrease of lipid peroxidation, cyclooxygenase-2 expression, and activation of phospho-STAT3 and phospho-SAPK/JNK. Finally, additional experiments showed that GC-1, which has no significant side effects on heart rate, prevented and reverted CMD-induced fat accumulation, and ameliorated steatohepatitis. These results indicate that TR agonists have the potential to inhibit or reverse hepatic steatosis induced by a nutritional model.


Subject(s)
Acetates/pharmacology , Fatty Liver/drug therapy , Phenols/pharmacology , Thyroid Hormone Receptors beta/agonists , Triiodothyronine/pharmacology , Animals , Base Sequence , DNA Primers/genetics , Diet , Disease Models, Animal , Fatty Liver/metabolism , Fatty Liver/pathology , Fatty Liver/prevention & control , Lipid Peroxidation/drug effects , Liver/drug effects , Liver/metabolism , Liver/pathology , Male , Rats , Rats, Inbred F344 , Triglycerides/metabolism
14.
Carcinogenesis ; 29(1): 161-8, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17893235

ABSTRACT

alpha-lipoic acid (alpha-LA) is an antioxidant used in a number of conditions related to liver diseases. Herein, we investigated the effect of alpha-LA on the development of rat pre-neoplastic lesions generated by a model of hepatocarcinogenesis, which has similarities in its histopathological sequence to human hepatocellular carcinoma development with cirrhosis. Initiation of hepatocytes was achieved by treatment with a single dose of diethylnitrosamine and promotion by feeding a choline-methionine-deficient diet (CMD), with or without alpha-LA. Pre-neoplastic lesions were identified by their positivity to the placental form of glutathione S-transferase (GSTP) or to gamma glutamyl transpeptidase. alpha-LA given to rats fed a CMD for 6 weeks dramatically increased the number of GSTP-positive foci as compared with rats fed a CMD alone (96/cm(2) versus 7/cm(2)), the mean foci area (0.033 versus 0.008 mm(2)) and the percentage of GSTP-positive liver tissue (3.01 versus 0.07%). Essentially similar results were obtained after 10 weeks of treatment. Co-treatment with CMD + alpha-LA also resulted in the enhancement of fat accumulation, lipid peroxidation and hepatocyte death; increased expression of tumor necrosis factor-alpha, cytochrome 2E1 and cyclooxygenase-2, enhanced activation of c-jun N-terminal kinase and signal transducer activator of transcription 3, and chronic hepatocyte proliferation was also observed. No such effects were observed when alpha-LA was added to a choline-supplemented diet. In conclusion, administration of alpha-LA in conditions associated with hepatic damage aggravates liver injury and stimulates the development of pre-neoplastic lesions; the results also suggest caution in its use in the presence of chronic liver injury.


Subject(s)
Antioxidants/pharmacology , Choline Deficiency/pathology , Liver Neoplasms/pathology , Precancerous Conditions/pathology , Thioctic Acid/pharmacology , Animals , Cell Death , Lipid Peroxidation , Liver Neoplasms/enzymology , Liver Neoplasms/metabolism , Precancerous Conditions/enzymology , Precancerous Conditions/metabolism , Rats
15.
Life Sci ; 75(3): 271-86, 2004 Jun 04.
Article in English | MEDLINE | ID: mdl-15135649

ABSTRACT

Although suppression of apoptosis has been implicated as a mechanism for the hepatocarcinogenicity of peroxisome proliferators (PPs), they can also induce cell death in rat AH130 and human HepG2 hepatoma cells. To study how PPs induce cell death and to characterize the molecular events involved, we administered the hypolipidemic BR931, a peroxisome proliferator, to rat hepatoma FaO cells. Treatment with increasing concentrations of BR931 (0.015 to 0.6 mM) reduced cell viability in a dose- and time-dependent manner, associated with DNA fragmentation and morphological changes characteristic of apoptosis. BR931 also caused phosphorylation of p53 within 3 hours, translocation of the pro-apoptotic Bax protein to mitochondria, release of cytochrome-c into the cytosol, and activation of caspase-9 and -3. These results indicated that BR931 activated the intrinsic caspase cascade. Pretreatment with three different antioxidants, N-acetylcysteine, Vitamin C and Trolox, reduced apoptosis, suggesting that reactive oxygen species (ROS) plays a role in BR931-induced apoptosis. In support of this hypothesis, BR931 produced increased levels of 8-hydroxy-deoxy-guanosine, a marker of DNA oxidative damage. Antioxidants prevented the p53 phosphorylation, up-regulation of Bax and BR931-induced apoptosis. These results suggest that BR931 can increase generation of ROS, leading to DNA damage and p53 phosphorylation, which, in turn, induces the activation of Bax, release of cytochrome-c from mitochondria and activation of caspases, culminating in cell death.


Subject(s)
Apoptosis/physiology , Genes, p53/physiology , Peroxisome Proliferators/pharmacology , Proto-Oncogene Proteins c-bcl-2 , Pyrimidines/pharmacology , Acetylcysteine/metabolism , Animals , Antioxidants/pharmacology , Apoptosis/genetics , Ascorbic Acid/pharmacology , Blotting, Western , Caspase 3 , Caspase 9 , Caspases/metabolism , Cell Line, Tumor , Cell Survival , Cytochromes c/physiology , Cytosol/metabolism , DNA/chemistry , DNA Fragmentation/physiology , Dose-Response Relationship, Drug , Electrophoresis, Agar Gel , Humans , In Situ Nick-End Labeling , Liver Neoplasms, Experimental/pathology , Mitochondria/metabolism , Phosphorylation , Protein Transport/physiology , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/physiology , Rats , Time Factors , bcl-2-Associated X Protein
16.
Carcinogenesis ; 24(6): 1059-65, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12807759

ABSTRACT

The nuclear receptor Constitutive Androstane Receptor (CAR) binds DNA as a heterodimer with the retinoic-X receptor and activates gene transcription. Previously, in vitro studies have shown that the testosterone metabolites, androstenol and androstenol, inhibit the constitutive transcriptional activity of CAR, suggesting that differences might exist in the response to CAR-mediated gene activation between different sexes. In this study, we have analyzed the response of female and male CD-1 mice to stimulation of hepatocyte proliferation caused by the CAR ligand TCPOBOP. Results showed that the labelling index of female hepatocytes at 24, 30 and 36 h after treatment was much higher than that found in males. The higher proliferative activity of female hepatocytes was associated with increased hepatic levels of cyclin D1, cyclin A, E2F and enhanced phosphorylation of pRb and p107. The increased mitogenic response of females was associated with higher mRNA levels of CYP2B10, a known target of CAR. Administration of androstenol to TCPOBOP-treated mice caused a reduction of labelling index, which was accompanied by a decrease of CYP2B10 and CAR mRNA levels. In conclusion, the results show that, in addition to microsomal detoxification, another biological response elicited by the CAR ligand TCPOBOP, namely, hepatocyte proliferation, occurs at higher levels in female than male mice, suggesting that CAR transcriptional activity in males is partially counteracted by physiological higher levels of testosterone metabolites such as androstenol and androstenol.


Subject(s)
Hepatocytes/drug effects , Pyridines/pharmacology , Receptors, Cytoplasmic and Nuclear/physiology , Transcription Factors/physiology , Androstanols/pharmacology , Animals , Aryl Hydrocarbon Hydroxylases/genetics , Cell Division/drug effects , Constitutive Androstane Receptor , Cyclin D1/genetics , Cytochrome P450 Family 2 , Female , Hepatocytes/physiology , Male , Mice , RNA, Messenger/analysis , Receptors, Cytoplasmic and Nuclear/genetics , Sex Characteristics , Steroid Hydroxylases/genetics , Transcription Factors/genetics
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