Biology subjects

Rousseau-Bacquie, E.

Publications and source records attributed to Rousseau-Bacquie, E..

5 recordsLinked to original sources

bioRxiv2026

The constitutive androstane receptor protects against metabolic dysfunction-associated steatotic liver disease through sex specific interactions with the gut microbiota

Background: The gut-liver axis is involved in Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD), but the host molecular actors involved in such dialogue have not yet been fully characterized. Objective: We investigated the sex-dependent role of the Constitutive Androstane Receptor (CAR) as a hepatic sensor of microbial signals in MASLD pathophysiology. Design: Male and female Car+/+ and Car-/- mice were fed a western diet (WD) for 4, 14 or 35 weeks. We performed plasma biochemistry, liver histology, bile acid and cholesterol quantification, untargeted multi-omics approach combining liver RNA-sequencing and 16S rRNA sequencing, together with co-housing, fecal microbiota transplantation and analysis of publicly available transcriptomics data in human cohorts. Results: Short-term WD revealed CAR-dependent protection against steatosis, together with perturbations in the transcriptional signatures of multiple transcription factors involved in hepatocyte identity in males. After 14 weeks, CAR deletion increased WD-induced liver damage, inflammation and fibrosis, and disrupted bile acid, cholesterol and gut microbiota homeostasis, in males only. Co-housing and fecal microbiota transplantations revealed that a Car+/+ gut microbiota protected against WD-induced liver damage, while a Car-/- microbiota was reshaped by a Car+/+ host. No CAR-dependent phenotype was observed in females. Finally, in human cohorts, hepatic CAR expression decreased in advanced clinical stages of MASLD. Conclusion: CAR is a sex-dependent protective nuclear receptor against MASLD progression, acting both as a transcriptional regulator of hepatocyte identity and as a mediator of the host-microbiota crosstalk.

physiology↗

bioRxiv2025

Soluble and insoluble dietary fibres differentially affect liver steatosis and gut microbiota in western-diet fed mice

ScopeMetabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic hepatic liver disease. An imbalance diet, rich in lipids and sugars and low in fibre, is a key contributing factor. However, there is limited knowledge about how soluble and fermentable dietary fibres, compared to insoluble and non-fermentable fibres, differently affect liver metabolism through their interactions with the intestinal microbiota. Methods and resultsMale mice housed at thermoneutrality were fed a Western Diet (WD) supplemented with fermentable inulin or non-fermentable cellulose for 18 weeks. Inulin supplementation mitigated WD-induced obesity, glucose intolerance, dyslipidemia and protected against WD-induced hepatic steatosis compared to cellulose. Hepatic gene expression changes induced by WD were attenuated with inulin. Additionally, inulin preserved gut microbiota composition and metabolism, indicating greater resilience against diet-induced perturbations. ConclusionThese findings suggest that soluble dietary fibres like inulin confer superior metabolic and hepatic benefits over insoluble fibres by modulating the gut microbiota-liver axis, highlighting their potential role in MASLD management.

physiology↗

bioRxiv2024

Effect of thermoneutral housing on MASLD severity, hepatic gene expression, and BAT activation during beta3-adrenergic stimulation in mice

Metabolic dysfunction-associated steatotic liver disease (MASLD), and its more advanced stage metabolic dysfunction-associated steatohepatitis, is the most common chronic liver disease, constituting a major public health issue. No medication is approved for MASLD treatment, and relevant preclinical models are needed to define molecular mechanisms underlying MASLD pathogenesis, and evaluate therapeutic approaches. Here we demonstrated that compared to standard temperature housing, thermoneutral housing aggravated western diet (WD)-induced obesity, diabetes, and steatosis in male mice, which was associated with increased hepatic expression of inflammation- and fibrosis-related genes. Accordingly, compared to standard-housed mice, thermoneutral-housed WD-fed mice developed more severe hepatic inflammation and fibrosis. The liver is the central metabolic organ in whole-body metabolic homeostasis. We used thermoneutrally housed mice with WD-induced MASLD to examine the effect of MASLD during {beta}3- adrenergic stimulation, and found that diet-induced MASLD was associated with defective inter- organ metabolic cross-talk, leading to impaired brown adipose tissue activation. HighlightsO_LIThermoneutral housing promotes WD-induced obesity and MASLD in mice C_LIO_LIThermoneutral housing fosters WD-induced change in gene expression C_LIO_LIThermoneutral housing fosters hepatic inflammation and fibrosis C_LIO_LIMASLD is associated with defective BAT response to {beta}3-adrenergic stimulation C_LI

physiology↗

bioRxiv2024

p110α-dependent hepatocyte signaling is critical for liver gene expression and its rewiring in MASLD

Insulin and other growth factors are key regulators of liver gene expression, including in metabolic diseases. Most of the phosphoinositide 3-kinase (PI3K) activity induced by insulin is dependent on PI3K. We used mice lacking p110, the catalytic subunit of PI3K, to investigate its role in the regulation of liver gene expression in health and in Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD). The absence of hepatocyte PI3K signaling promoted glucose intolerance in lean mice and significantly regulated liver gene expression, including insulin-sensitive genes, in ad libitum feeding. Some of the defective regulation of gene expression in response to hepatocyte-restricted insulin receptor deletion was related to PI3K signaling. In addition, though PI3K deletion in hepatocytes promoted insulin resistance, it was protective against steatotic liver disease in diet-induced obesity. In the absence of hepatocyte PI3K, the effect of diet-induced obesity on liver gene expression was significantly altered, with changes in rhythmic gene expression in liver. Altogether, this study highlights the specific role of p110 in the control of liver gene expression in physiology and in the metabolic rewiring that occurs during MASLD.

cell biology↗

bioRxiv2023

Pharmacological activation of constitutive androstane receptor induces female-specific modulation of hepatic metabolism

Background and AimsThe constitutive androstane receptor (CAR) is a nuclear receptor able to recognize a large panel of xenobiotics leading to the modulation of the expression of its target genes involved in xenobiotic detoxication and energy metabolism. While CAR hepatic activity is thought to be higher in women than in men, its response to an acute pharmacological activation has never been investigated in both sexes. MethodsHepatic transcriptome, plasma and hepatic metabolome, have been analyzed in Car+/+ and Car-/- male and female mice treated either with the CAR-specific agonist, 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP), or with vehicle. ResultsWhile 90% of TCPOBOP-sensitive genes were modulated in a sex- independent way, the remaining 10% were almost exclusively impacted in female liver specifically. These female-specific CAR-sensitive genes were mainly involved in xenobiotic metabolism, inflammation and extracellular matrix organization. CAR activation also induced higher hepatic oxidative stress and hepatocyte cytolysis in females than in males. Data mining on human data confirmed that CAR activation may be involved in sexually-dimorphic drug-induced liver injury. Hepatic expression of flavin monooxygenase 3 (Fmo3) was almost abolished and associated with a decrease of hepatic trimethylamine-N-oxide (TMAO) concentration in TCPOBOP-treated females. In line with a possible role in the control of TMAO homeostasis, CAR activation decreased platelet hyperresponsiveness in female mice supplemented with dietary choline. ConclusionsOur results demonstrate that more than 10% of CAR-sensitive genes are sex-specific and influence hepatic and systemic response such as platelet aggregation. Also, CAR activation may be an important mechanism of sexually- dimorphic drug-induced liver injury.

pharmacology and toxicology↗