Biology subjects

Corlu, A.

Publications and source records attributed to Corlu, A..

6 recordsLinked to original sources

bioRxiv2026

Voluntary wheel running selectively preserves skeletal muscle during pancreatic cancer cachexia despite persistent systemic alterations

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) is frequently associated with cancer cachexia, involving alterations across multiple physiological systems. Whether distinct exercise paradigms similarly influence these compartments remains unclear. We compared voluntary wheel running (VWR) and treadmill running (TR) using an integrative physiological approach in a murine model of pancreatic cancer cachexia. Methods Male C57BL/6J mice bearing UN-KC-6141 pancreatic tumor cells were allocated to inactive control (CaCTL), VWR or TR groups and compared with healthy controls. Tumor progression, body composition, skeletal muscle, adipose tissue, hepatic metabolism, systemic inflammation, energy expenditure and behavior were assessed. Analysis of covariance determined whether tissue-mass differences remained evident after adjustment for tumor burden. Results UN-KC-6141 tumors induced a systemic cachectic phenotype involving skeletal muscle and adipose tissue wasting, hepatic metabolic remodeling, systemic inflammation and behavioral alterations. VWR slowed tumor growth, reduced final tumor mass, improved the body-weight trajectory and preserved lean and skeletal muscle mass, whereas TR did not reproduce these adaptations. Greater gastrocnemius mass with VWR remained evident after adjustment for tumor mass, indicating that reduced tumor burden alone was insufficient to account for muscle preservation. In contrast, adipose tissue wasting, hepatic metabolic remodeling and systemic inflammation remained largely unaffected. TR was also associated with a less favorable body-weight trajectory and greater fat mass loss than in inactive tumor-bearing mice. Exploratory metabolic phenotyping revealed distinct feeding, sleep and resting energy expenditure patterns between the two exercise paradigms. Conclusions VWR selectively preserved skeletal muscle within a persistently altered systemic environment, whereas the TR protocol used here did not reproduce these adaptations. These findings reveal tissue-specific exercise responsiveness during pancreatic cancer cachexia and highlight exercise paradigm characteristics as determinants of tumor-host adaptation.

physiology↗

bioRxiv2025

Stable lentiviral-mediated expression of Cytochrome P450 2D6 in HepaRG cells: New means for in vitro assessment of xenobiotic biotransformation and cytotoxicity

Primary cultures of Human Hepatocytes (PHH) are the gold standard to investigate drug-hepatotoxicity in vitro, however, large-scale studies using these primary liver cells are not possible because of the shortage in liver biopsies. HepaRG model is often considered as the closest surrogate to PHH for toxicity studies in vitro. However, differentiated HepaRG cells express very low levels of the cytochrome P450 2D6 (CYP2D6) protein, which is essential for the biotransformation of nearly 25% of drugs on the market. To overcome this limitation, infection of progenitor HepaRG cells were performed using lentiviral particles containing a transgene encoding a single mRNA translated into a polypeptide undergoing proteolytic cleavage via the T2A peptide to produce both CYP2D6 and GFP. Differentiated HepaRG cells transduced with lentivirus stably expressed GFP and catalytically active human CYP2D6 enzyme at levels close to those found in high PHH metabolizers. As expected, CYP2D6 protein was found mostly located in the endoplasmic reticulum. Using the CYP2D6 transgenic HepaRG cells, we showed that tramadol was metabolized in both, N- and O-desmethyl tramadol as observed in human serum in contrast with the production of N-desmethyl tramadol only in parental HepaRG cells via the CYP3A4 catalytic activity. Similarly, after perhexiline (PHX) treatments, higher IC50 were found in CYP2D6 expressing HepaRG cells associated to lower mitochondrial damages compared to those found in parental cells for the same PHX concentrations. Gene profiling between parental and transgenic cells demonstrated that the CYP2D6 expressing HepaRG cells had kept their ability to proliferate and differentiate with low impact on the expression of the hepatocyte specific functions. However, we identified a limited set of genes such as NXF3 and TRIM63, which were up-regulated by the mRNA encoded by the lentiviral transgene. Together, these data confirmed that the CYP2D6 transgenic HepaRG cells represent a suitable optimized transgenic model of HepaRG cells to evaluate biotransformation and toxicity of specific compounds metabolized by CYP2D6.

cell biology↗

bioRxiv2024

PPARgamma, a key modulator of metabolic reprogramming, stemness and chemoresistance associated with retrodifferentiation in human hepatocellular carcinomas

Human hepatocellular carcinomas (HCCs) with cancer stem cell (CSC) features are a subclass of therapeutically challenging cancers. We recently showed that retrodifferentiation of hepatic cancer cells into CSC-like cells leads to metabolic reprogramming and chemoresistance. The molecular mechanisms whereby differentiated cancer cells switch towards a CSC phenotype are poorly understood. By studying metabolic reprogramming associated with HCC cell plasticity, we identified an unsuspected role of peroxisome proliferator-activated receptor (PPAR){gamma} in hepatic CSC phenotype acquisition. Gene expression and metabolic analyses performed throughout cell differentiation/retrodifferentiation process of human HepaRG and HBG-BC2 HCC cells show that metabolic reprogramming in hepatic CSCs is associated with fragmented mitochondrial network, decreased respiration, de novo lipogenesis, fatty acid oxidation, but increased glycolysis and lipid storage. Mitochondrial genes downregulated in HepaRG-CSCs are also downregulated in the STEM HCC subclass. While PPAR is the main isoform in differentiated hepatic cells, we find high PPAR{gamma} expression in hepatic CSCs. Accordingly, nuclear localization of PPAR{gamma} is detected in human HCC tumors and PPAR{gamma}high/PPARlow expression is associated with the STEM HCC subclass and a poor outcome in human HCC cohorts. PPAR{gamma} silencing or/and inhibition of its target gene pyruvate dehydrogenase kinase 4 reactivates cell respiration, increases reactive oxygen species production and sensitizes hepatic CSCs to chemotherapy. Conversely, PPAR activation synergizes with chemotherapy to induce cell death. Targeting PPAR{gamma}, a key regulator of metabolic reprogramming and stemness in hepatic CSCs, or modulating the PPAR{gamma}/PPAR balance that finely tunes the differentiation/retrodifferentiation process in HCC deserves further investigation for antitumor therapy. Implications heading and statementPPAR{gamma}, a key regulator of metabolic reprogramming and stemness in hepatic CSC, reduces oxidative phosphorylation and reactive oxygen species production, therefore contributing to HCC chemoresistance.

cancer biology↗

bioRxiv2024

The dithiocarbamate pesticides maneb and mancozeb disturb the metabolism of lipids and xenobiotics in an in vitro model of metabolic dysfunction-associated steatotic liver disease

Pesticides are increasingly recognized to be hepatotoxic but less is known about their toxicity in metabolic dysfunction-associated steatotic liver disease (MASLD). Recent investigations reported oxidative stress-induced apoptosis in differentiated hepatocyte-like HepaRG cells after a single treatment with a 7-pesticide mixture that included chlorpyrifos, dimethoate, diazinon, iprodione, imazalil, and the dithiocarbamates maneb and mancozeb. These effects were reproduced by maneb, mancozeb, or manganese chloride (MnCl2). Herein, differentiated HepaRG cells cultured for 2 weeks without (-FA) or with (+FA) a mixture of stearic and oleic acids were treated with this 7-pesticide mixture, maneb, mancozeb, or MnCl2 along the same period. While these molecules did not induce neutral lipid accumulation in -FA-HepaRG cells, they worsened steatosis in +FA-HepaRG cells. Maneb or MnCl2 impaired very low-density lipoprotein (VLDL) secretion and increased fatty acid uptake without altering mitochondrial fatty acid oxidation and de novo lipogenesis. Reduced VLDL secretion was associated with decreased mRNA levels of apolipoproteins B and C3 and microsomal triglyceride transfer protein. Zinc supplementation restored VLDL secretion, reduced fatty acid uptake and prevented the exacerbation of steatosis in +FA-HepaRG cells treated with mancozeb or MnCl2. The mixture, maneb, or MnCl2 also reduced the mRNA expression and activity of several cytochromes P450 in +FA- and -FA-HepaRG cells. This was associated with impaired biotransformation of diazinon while chlorpyrifos metabolism was unaffected. Hence, maneb, mancozeb and MnCl2 disturb the metabolism of lipids and xenobiotics in HepaRG cells, in particular in fatty acid-exposed cells. These findings could have major pathophysiological consequences in dithiocarbamate-exposed individuals with MASLD.

pharmacology and toxicology↗

bioRxiv2023

Low concentrations of ethylene bisdithiocarbamate pesticides maneb and mancozeb impair manganese and zinc homeostasis to induce oxidative stress and caspase-dependent apoptosis in human hepatocytes

The worldwide and intensive use of phytosanitary compounds results in environmental and food contamination by chemical residues. Human exposure to multiple pesticide residues is a major health issue. Considering that the liver is not only the main organ for metabolizing pesticides but also a major target of toxicities induced by xenobiotics, we studied the effects of a mixture of 7 pesticides (chlorpyrifos-ethyl, dimethoate, diazinon, iprodione, imazalil, maneb, mancozeb) often detected in food samples. Effects of the mixture was investigated using metabolically competent HepaRG cells and human hepatocytes in primary culture. We report the strong cytotoxicity of the pesticide mixture towards hepatocytes-like HepaRG cells and human hepatocytes upon acute and chronic exposures at low concentrations extrapolated from the Acceptable Daily Intake (ADI) of each compound. Unexpectedly, we demonstrated that the manganese (Mn)-containing dithiocarbamates (DTCs) maneb and mancozeb were solely responsible for the cytotoxicity induced by the mixture. The mechanism of cell death involved the induction of oxidative stress, which led to cell death by intrinsic apoptosis involving caspases 3 and 9. Importantly, this cytotoxic effect was found only in cells metabolizing these pesticides. Herein, we unveil a novel mechanism of toxicity of the Mn-containing DTCs maneb and mancozeb through their metabolization in hepatocytes generating the main metabolite ethylene thiourea (ETU) and the release of Mn leading to intracellular Mn overload and depletion in zinc (Zn). Alteration of the Mn and Zn homeostasis provokes the oxidative stress and the induction of apoptosis, which can be prevented by Zn supplementation. Our data demonstrate the hepatotoxicity of Mn-containing fungicides at very low doses and unveil their adverse effect in disrupting Mn and Zn homeostasis and triggering oxidative stress in human hepatocytes.

pharmacology and toxicology↗

bioRxiv2020

Long read sequencing and de novo assembly of Hepatitis B Virus identifies 5mCpG in CpG islands

Hepatitis B Virus (HBV) is a 3.2KB DNA virus that causes acute and chronic hepatitis. HBV infection is a world health problem, with 350 million chronically infected people at increased risk of developing liver disease and hepatocellular carcinoma (HCC). Methylation of HBV DNA in a CpG context (5mCpG) can alter the expression patterns of viral genes related to infection and cellular transformation. Moreover, it may also provide clues to why certain infections are cleared, or persist with or without progression to cancer. The detection of 5mCpG often requires techniques that damage DNA or introduce bias through a myriad of limitations. Therefore, we developed a method for the detection of 5mCpG on the HBV genome that does not rely on bisulfite conversion or PCR. With cas9 guided RNPs to specifically target the HBV genome, we enriched in HBV DNA from Primary Human Hepatocytes (PHH) infected with different HBV genotypes, as well as enriching in HBV from infected patient liver tissue; followed by sequencing with Oxford Nanopore Technologies MinION. Detection of 5mCpG by Nanopore sequencing was benchmarked with Bisulfite-quantitative Methyl Specific PCR (BS-qMSP). 5mCpG levels in HBV determined by BS-qMSP and Nanopore sequencing were highly correlated. Our Nanopore sequencing approach achieved a coverage of [~]2000x of HBV depending on infection efficacy, sufficient coverage to perform a de novo assembly and detect small fluctuations in HBV methylation, providing the first de novo assembly of native HBV DNA, as well as the first landscape of 5mCpG from native HBV sequences. Moreover, by capturing entire HBV genomes, we explored the epigenetic heterogeneity of HBV in infected patients and identified 4 epigenetically distinct clusters based on methylation profiles. This method is a novel approach that enables the enrichment of viral DNA in a mixture of nucleic acid material from different species and will serve as a valuable tool for infectious disease monitoring.

genomics↗