Transplantation of peripheral blood progenitor cells from HLA-identical sibling donors

Transplantation of peripheral blood progenitor cells (PBPCs) has largely replaced autologous bone marrow transplantation. The same might occur in the allogeneic setting if the favourable initial experience with allogeneic PBPCT is confirmed. We analysed all primary transplants utilizing unmodified PBPC from HLA-identical sibling donors reported to the European Group for Blood and Marrow Transplantation (EBMT) for 1994. 59 patients with a median age of 39 years received myeloablative therapy for acute myelogenous leukaemia (23 patients), acute lymphoblastic leukaemia (13), chronic myelogenous leukaemia (nine), lymphoma (seven), or other diagnoses (seven) mostly of advanced stages followed by transplantation of allogeneic PBPC. Three patients died soon after grafting, the others showed prompt haemopoietic recovery with median times to recover an absolute neutrophil count (ANC) above 0.5 and 1.0×10⁹/l of 15 (range 9–27) and 17 d (range 10–28) respectively. Time to platelet recovery above 20 or 50×10⁹/l was 16 (range 9–76) and 18 d (range 12–100) respectively. 27 patients (46%) developed no or mild acute graft-versus-host disease (GVHD). The incidence of moderate (grade II) disease was 27%; 24% of the patients developed severe acute GVHD (grades III or IV). 55% of patients who were alive 90 d after transplantation developed chronic GVHD, the probability to develop extensive chronic GVHD was 32% (95% confidence interval 22–42) with a median follow-up of 14 months. Overall and event-free survival (EFS) at 1 year were 54% (CI 48–60) and 50% (CI 43–57), respectively, the relapse incidence was 23% (CI 17–29). EFS was 67% (CI 55–79) in patients transplanted for acute leukaemias in first complete remission, chronic myelogenous leukaemia in first chronic phase, or severe aplastic anaemia. Transplantation of allogeneic PBPC resulted in prompt and durable engraftment. The incidence and severity of acute and chronic GVHD seemed comparable to that observed after allogeneic BMT. Overall and event-free survival in this cohort of patients, most of whom suffered from advanced leukaemia or lymphoma, is encouraging, suggesting that the high numbers of T lymphocytes and/or natural killer cells contained in a typical PBPC collection product exert a vigorous graft-versus-leukaemia effect. Further evaluation of allogeneic PBPCT is highly desirable.     

Induction of vesicular steatosis by amiodarone and tetracycline is associated with up-regulation of lipogenic genes in HepaRG cells

Drug-induced liver injury occurs in general after several weeks and is often unpredictable. It is characterized by a large spectrum of lesions that includes steatosis and phospholipidosis. Many drugs such as amiodarone and tetracycline have been reported to cause phospholipidosis and/or steatosis. In this study, acute and chronic hepatic effects of these two drugs were investigated using well-differentiated human hepatoma HepaRG cells. Accumulation of typical lipid droplets, labeled with Oil Red O, was observed in hepatocyte-like HepaRG cells after repeat exposure to either drug. Amiodarone caused the formation of additional intracytoplasmic vesicles that did not stain in all HepaRG cells. At the electron microscopic level, these vesicles appeared as typical lamellar bodies and were associated with an increase of phosphatidylethanolamine and phosphatidylcholine. A dose-dependent induction of triglycerides (TG) was observed after repeat exposure to either amiodarone or tetracycline. Several genes known to be related to lipogenesis were induced after treatment by these two drugs. By contrast, opposite deregulation of some of these genes (FASN, SCD1, and THSRP) was observed in fat HepaRG cells induced by oleic acid overload, supporting the conclusion that different mechanisms were involved in the induction of steatosis by drugs and oleic acid. Moreover, several genes related to lipid droplet formation (ADFP, PLIN4) were up-regulated after exposure to both drugs and oleic acid. CONCLUSION: Our results show that amiodarone causes phospholipidosis after short-term treatment and, like tetracycline, induces vesicular steatosis after repeat exposure in HepaRG cells. These data represent the first demonstration that drugs can induce vesicular steatosis in vitro and show a direct relationship between TG accumulation and enhanced expression of lipogenic genes.     

Treatment of Refractory and Relapsed Adult Acute Leukemia Using a Uniform Chemotherapy Protocol

Twenty-nine adult patients with relapsed (21) or refractory (8) de novo acute leukemia (12 ALL and 17 ANLL) were treated with a remission-induction salvage chemotherapeutic protocol including vindesine, mitoxantrone, cyclophosphamide, intermediate-dose cytosine arabinoside, prednisolone and methotrexate. Ten of seventeen (59%) ANLL and 8/12 ALL (67%) achieved complete remission (CR). Seven of eight (86%) cases refractory to first-line remission-induction therapy (3/4 ANLL and 4/4 ALL) entered complete remission. The most frequent non-hematologic side effects were gastrointestinal. All patients experienced severe pancytopenia, with median times to recovery of granulocyte and platelet counts of 28 and 29 days, respectively. Nine of twenty-nine (31%) patients suffered febrile episodes of unknown origin and 13/29 (45%) suffered documented infections. Five patients (17%) died while aplastic, four from infection and one from cardiotoxicity. Four patients who entered CR were submitted to a bone marrow transplantation (BMT), two autologous and two allogeneic BMT. Sixteen of the 18 patients who entered CR relapsed, with a median remission duration of 3.5 ± 2.9 months. Two patients remain in remission at 5+ and 17+ months. These results suggest that this protocol is an effective remission-induction salvage therapy for adult acute leukemias.     

Differential toxicity of heterocyclic aromatic amines and their mixture in metabolically competent HepaRG cells

Human exposure to heterocyclic aromatic amines (HAA) usually occurs through mixtures rather than individual compounds. However, the toxic effects and related mechanisms of co-exposure to HAA in humans remain unknown. We compared the effects of two of the most common HAA, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), individually or in combination, in the metabolically competent human hepatoma HepaRG cells. Various endpoints were measured including cytotoxicity, apoptosis, oxidative stress and DNA damage by the comet assay. Moreover, the effects of PhIP and/or MeIQx on mRNA expression and activities of enzymes involved in their activation and detoxification pathways were evaluated. After a 24 h treatment, PhIP and MeIQx, individually and in combination, exerted differential effects on apoptosis, oxidative stress, DNA damage and cytochrome P450 (CYP) activities. Only PhIP induced DNA damage. It was also a stronger inducer of CYP1A1 and CYP1B1 expression and activity than MeIQx. In contrast, only MeIQx exposure resulted in a significant induction of CYP1A2 activity. The combination of PhIP with MeIQx induced an oxidative stress and showed synergistic effects on apoptosis. However, PhIP-induced genotoxicity was abolished by a co-exposure with MeIQx. Such an inhibitory effect could be explained by a significant decrease in CYP1A2 activity which is responsible for PhIP genotoxicity. Our findings highlight the need to investigate interactions between HAA when assessing risks for human health and provide new insights in the mechanisms of interaction between PhIP and MeIQx.     

Influence of puffing conditions on the carbonyl composition of e-cigarette aerosols

Owing to their harmful effects on human health, the presence of carbonyl compounds in e-cigarette aerosols raises concerns. To date, the reported concentration levels in e-vapors vary greatly between studies and several factors that markedly influence carbonyl emission during vaping have been highlighted including the heating temperature, the power supply, the device architecture, the filling level of the tank and the main e-liquid constituents. This study investigated the impact of puffing regimen parameters on the carbonyl composition of e-cigarette aerosols with the aim of: (1) better estimating the variability of carbonyl emissions depending on puffing conditions; (2) highlighting puffing profiles that increase the exposure to carbonyls; and (3) estimating to what extent puffing topography could be implied in the variability of carbonyl concentrations reported in the current literature.E-vapors from a single e-liquid were generated from two e-cigarette models with a smoking machine. A total of 7 different puffing regimens were used to individually study the influence of the puff volume, duration and frequency. Carbonyls were collected by DNPH cartridges and analysed by HPLC-UV. E-liquid consumption and e-vapor temperature were also monitored.E-vapor concentrations of formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde and methylglyoxal were affected, sometimes differently, by the modification of the puffing regimen, as well as by the e-cigarette model. For example, formaldehyde concentration ranged from 20 to 255 ng/puff depending on the puffing conditions. The results of principal component analyses, applied to the concentration data sets for the 6 carbonyls, suggest that the studied parameters interact and highlight some “carbonyl-emitting” combinations of concern (e-cigarette model/puffing regimen). However, the highest concentrations measured in the present study remain far lower than those observed in conventional cigarette mainstream smoke.This study confirms that the chosen puffing regimen contributes a part of the observed variability in the carbonyl levels reported in the scientific literature, hampering comparisons between studies and making interpretation difficult. Thus, harmonized and realistic protocols for the assessment of e-cigarette toxicity by physicochemical or experimental approaches are clearly needed.     

Optimization of the HepaRG cell model for drug metabolism and toxicity studies

The HepaRG cell line is the first human cell line able to differentiate in vitro into mature hepatocyte-like cells. Our main objective within the framework of the EEC-LIINTOP project was to optimize the use of this cell line for drug metabolism and toxicity studies, especially after repeat treatments. The main results showed that differentiated HepaRG cells: (i) retained their drug metabolism capacity (major CYPs, phase 2 enzymes, transporters and nuclear receptors) and responsiveness to prototypical inducers at relatively stable levels for several weeks at confluence. The levels of several functions, including some CYPs such as CYP3A4, were dependent on the addition of dimethyl sulfoxide in the culture medium; (ii) sustained the different types of chemical-induced hepatotoxicity, including steatosis, phospholipidosis and cholestasis, after acute and/or repeat treatment with reference drugs. In particular, drug-induced vesicular steatosis was demonstrated in vitro for the first time. In conclusion, our results from the LIINTOP project, together with other studies reported concomitantly or more recently in the literature, support the conclusion that the metabolically competent human HepaRG cells represent a surrogate to primary human hepatocytes for investigating drug metabolism parameters and both acute and chronic effects of xenobiotics in human liver.     

Chronic exposure to low doses of pharmaceuticals disturbs the hepatic expression of circadian genes in lean and obese mice

Drinking water can be contaminated with pharmaceuticals. However, it is uncertain whether this contamination can be harmful for the liver, especially during obesity. Hence, the goal of our study was to determine whether chronic exposure to low doses of pharmaceuticals could have deleterious effects on livers of lean and obese mice. To this end, lean and ob/ob male mice were treated for 4 months with a mixture of 11 drugs provided in drinking water at concentrations ranging from 10 to 10⁶ ng/l. At the end of the treatment, some liver and plasma abnormalities were observed in ob/ob mice treated with the cocktail containing 10⁶ ng/l of each drug. For this dosage, a gene expression analysis by microarray showed altered expression of circadian genes (e.g. Bmal1, Dbp, Cry1) in lean and obese mice. RT-qPCR analyses carried out in all groups of animals confirmed that expression of 8 different circadian genes was modified in a dose-dependent manner. For some genes, a significant modification was observed for dosages as low as 10²–10³ ng/l. Drug mixture and obesity presented an additive effect on circadian gene expression. These data were validated in an independent study performed in female mice. Thus, our study showed that chronic exposure to trace pharmaceuticals disturbed hepatic expression of circadian genes, particularly in obese mice. Because some of the 11 drugs can be found in drinking water at such concentrations (e.g. acetaminophen, carbamazepine, ibuprofen) our data could be relevant in environmental toxicology, especially for obese individuals exposed to these contaminants.     

Preferential induction of the AhR gene battery in HepaRG cells after a single or repeated exposure to heterocyclic aromatic amines

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) are two of the most common heterocyclic aromatic amines (HAA) produced during cooking of meat, fish and poultry. Both HAA produce different tumor profiles in rodents and are suspected to be carcinogenic in humans. In order to better understand the molecular basis of HAA toxicity, we have analyzed gene expression profiles in the metabolically competent human HepaRG cells using pangenomic oligonucleotide microarrays, after either a single (24-h) or a repeated (28-day) exposure to 10 μM PhIP or MeIQx. The most responsive genes to both HAA were downstream targets of the arylhydrocarbon receptor (AhR): CYP1A1 and CYP1A2 after both time points and CYP1B1 and ALDH3A1 after 28 days. Accordingly, CYP1A1/1A2 induction in HAA-treated HepaRG cells was prevented by chemical inhibition or small interference RNA-mediated down-regulation of the AhR. Consistently, HAA induced activity of the CYP1A1 promoter, which contains a consensus AhR-related xenobiotic-responsive element (XRE). In addition, several other genes exhibited both time-dependent and compound-specific expression changes with, however, a smaller magnitude than previously reported for the prototypical AhR target genes. These changes concerned genes mainly related to cell growth and proliferation, apoptosis, and cancer. In conclusion, these results identify the AhR gene battery as the preferential target of PhIP and MeIQx in HepaRG cells and further support the hypothesis that intake of HAA in diet might increase human cancer risk.     

PPAR agonists reduce steatosis in oleic acid-overloaded HepaRG cells

Although non-alcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease there is no pharmacological agent approved for its treatment. Since peroxisome proliferator-activated receptors (PPARs) are closely associated with hepatic lipid metabolism, they seem to play important roles in NAFLD. However, the effects of PPAR agonists on steatosis that is a common pathology associated with NAFLD, remain largely controversial. In this study, the effects of various PPAR agonists, i.e. fenofibrate, bezafibrate, troglitazone, rosiglitazone, muraglitazar and tesaglitazar on oleic acid-induced steatotic HepaRG cells were investigated after a single 24-hour or 2-week repeat treatment. Lipid vesicles stained by Oil-Red O and triglycerides accumulation caused by oleic acid overload, were decreased, by up to 50%, while fatty acid oxidation was induced after 2-week co-treatment with PPAR agonists. The greatest effects on reduction of steatosis were obtained with the dual PPARα/γ agonist muraglitazar. Such improvement of steatosis was associated with up-regulation of genes related to fatty acid oxidation activity and down-regulation of many genes involved in lipogenesis. Moreover, modulation of expression of some nuclear receptor genes, such as FXR, LXRα and CAR, which are potent actors in the control of lipogenesis, was observed and might explain repression of de novo lipogenesis.