Publications by authors named "Champy M"

Background And Objective: Overweight and obesity affects millions of individuals worldwide and consequently represents a major public health concern. Individuals living with overweight and obesity have difficulty maintaining a low body weight due to known physiological mechanisms which prevent further weight loss and drive weight regain. In contrast, mechanisms which promote low body weight maintenance receive less attention and are largely unknown.

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For children who work, there has been little research into the intricate relationship between their home lives and their work lives and the implications that this relationship might hold for their psychosocial development and functioning. This cross-sectional study was conducted in the Amhara region, Ethiopia, between March and April 2020 on a sample of 1311 working children with the aim, in part, of exploring ways in which various dimensions of children's psychological wellbeing are influenced by their working conditions and their family contexts. In addition to collecting data on some personal traits, family relationships, home environments, and detailed occupational characteristics, we gathered information on psychosocial wellbeing using 22 items from the Instrument for the Psychosocial Assessment of Working Children (IPAC).

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Insulin resistance is a major public health burden that often results in other comorbidities including type 2 diabetes, nonalcoholic fatty liver disease (NAFLD), and cardiovascular disease. An insulin sensitizer has the potential to become a disease-modifying therapy. It remains an unmet medical need to identify therapeutics that target the insulin signaling pathway to treat insulin resistance.

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Microglia play a critical role in maintaining neural function. While microglial activity follows a circadian rhythm, it is not clear how this intrinsic clock relates to their function, especially in stimulated conditions such as in the control of systemic energy homeostasis or memory formation. In this study, we found that microglia-specific knock-down of the core clock gene, Bmal1, resulted in increased microglial phagocytosis in mice subjected to high-fat diet (HFD)-induced metabolic stress and likewise among mice engaged in critical cognitive processes.

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  • Spinocerebellar ataxia type 7 (SCA7) is a genetic disorder that leads to motor incoordination due to the degeneration of the cerebellum, caused by mutations in the ATXN7 gene that involve polyglutamine expansion.
  • In a study using a new SCA7 knock-in mouse model, researchers found that gene expression changes significantly affected Purkinje cells, which are crucial for motor coordination, indicating that early gene downregulation contributes to severe motor and behavioral impairments.
  • The study reveals common molecular mechanisms across different types of spinocerebellar ataxias, suggesting potential therapeutic targets and shows that both male and female SCA7 mice exhibit key symptoms present in human
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The genetic landscape of diseases associated with changes in bone mineral density (BMD), such as osteoporosis, is only partially understood. Here, we explored data from 3,823 mutant mouse strains for BMD, a measure that is frequently altered in a range of bone pathologies, including osteoporosis. A total of 200 genes were found to significantly affect BMD.

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Circadian systems provide a fitness advantage to organisms by allowing them to adapt to daily changes of environmental cues, such as light/dark cycles. The molecular mechanism underlying the circadian clock has been well characterized. However, how internal circadian clocks are entrained with regular daily light/dark cycles remains unclear.

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  • High-throughput phenomic projects often deal with complex data from various treatment and control groups, which can complicate analyses due to variations over time, necessitating a method to effectively use local controls to enhance analytic accuracy.
  • The authors present 'soft windowing', a method that assigns weighted importance to control data based on their proximity in time to mutant data, leading to reduced false positives (10%) in analyses and increased significant P-values (30%).
  • This method is implemented in an R package called SmoothWin, which is publicly accessible and can also be applied to large-scale human phenomic studies such as the UK Biobank.
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Metabolic diseases are a worldwide problem but the underlying genetic factors and their relevance to metabolic disease remain incompletely understood. Genome-wide research is needed to characterize so-far unannotated mammalian metabolic genes. Here, we generate and analyze metabolic phenotypic data of 2016 knockout mouse strains under the aegis of the International Mouse Phenotyping Consortium (IMPC) and find 974 gene knockouts with strong metabolic phenotypes.

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  • Metabolic syndrome involves issues like obesity, high blood pressure, and glucose intolerance, with oxidative stress playing a key role in these conditions.
  • The study aimed to see if blocking the Nox4 enzyme could help improve blood pressure and metabolic issues in mice on a high-fat diet or receiving angiotensin II injections.
  • Results showed that Nox4 inhibition had protective effects against blood pressure increases and reduced triglycerides in normal diet conditions, but it did not prevent heart damage or improve outcomes on a high-fat diet, especially worsening glucose tolerance in female mice.
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  • ATP6AP2 is a gene that helps make a receptor important for converting a substance in the body, which is why it's a target for new drugs.
  • When scientists turned off this gene in mice, it caused serious problems in different organs, showing it's really important for health.
  • If ATP6AP2 is disrupted in adult mice, they quickly get sick and even die, highlighting that any drugs affecting this gene must be very carefully tested to avoid harm.
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  • - Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder linked to a repeated sequence of CGG in the FMR1 gene, which can lead to two mechanisms of pathology: RNA gain-of-function and production of a harmful protein called FMRpolyG.
  • - Research using transgenic mice showed that while the RNA alone does not cause harm, the presence of FMRpolyG is pathogenic and disrupts the structure of nuclear lamina in neurons derived from FXTAS patient cells.
  • - The study found that the protein LAP2β can counteract the neuronal damage caused by FMRpolyG, indicating that changes in nuclear lamina architecture play a significant role in the
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Mutations of the AMP-activated kinase gamma 2 subunit (AMPKγ2), N488I (AMPKγ2) and R531G (AMPKγ2), are associated with Wolff-Parkinson-White (WPW) syndrome, a cardiac disorder characterized by ventricular pre-excitation in humans. Cardiac-specific transgenic overexpression of human AMPKγ2 or AMPKγ2 leads to constitutive AMPK activation and the WPW phenotype in mice. However, overexpression of these mutant proteins also caused profound, non-physiological increase in cardiac glycogen, which might abnormally alter the true phenotype.

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Background: Mouse transgenesis has provided the unique opportunity to investigate mechanisms underlying sodium kidney reabsorption as well as end organ damage. However, understanding mouse background and the experimental conditions effects on phenotypic readouts of engineered mouse lines such as blood pressure presents a challenge. Despite the ability to generate high sodium and chloride plasma levels during high-salt diet, observed changes in blood pressure are not consistent between wild-type background strains and studies.

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  • BAHD1 is a protein that helps form heterochromatin and repress genes, but its specific roles in the body were previously unclear.
  • Researchers found that when the Bahd1 gene is removed in mice, it leads to lower cholesterol and blood sugar levels, reduced body fat, smaller placentas, decreased fetal weight, and higher neonatal mortality.
  • The study shows that BAHD1 interacts with MIER proteins to regulate genes related to lipid metabolism and plays a crucial role in placental development and body fat storage, suggesting that issues with BAHD1 could be linked to various human diseases.
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The 16p11.2 600 kb BP4-BP5 deletion and duplication syndromes have been associated with developmental delay; autism spectrum disorders; and reciprocal effects on the body mass index, head circumference and brain volumes. Here, we explored these relationships using novel engineered mouse models carrying a deletion (Del/+) or a duplication (Dup/+) of the Sult1a1-Spn region homologous to the human 16p11.

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  • The central circadian clock in the SCN regulates our daily rhythms and synchronizes peripheral circadian clocks to maintain balance in the body.
  • Research in mice revealed that an unusual feeding schedule during rest affects these peripheral clocks without altering the SCN clock, causing a misalignment between them.
  • This misalignment is due to the absence of certain receptors in the SCN that would normally respond to the feeding schedule, leading to issues like diabetes and obesity over time, similar to problems faced by people with shift work.
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Objective: Left-ventricular hypertrophy and interstitial fibrosis are the main pathophysiological factors of heart failure with preserved ejection fraction. Blockade of the serotonin 5-HT2B receptor (5-HT2BR) has been shown to reduce cardiac hypertrophy, oxidative stress, and extracellular cell matrix activation. In this study, we evaluated the effects of the 5-HT2BR blockade, on hemodynamic and cardiac remodeling, in spontaneously hypertensive rats (SHRs) that display a diastolic dysfunction with preserved ejection fraction.

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The function of the majority of genes in the mouse and human genomes remains unknown. The mouse embryonic stem cell knockout resource provides a basis for the characterization of relationships between genes and phenotypes. The EUMODIC consortium developed and validated robust methodologies for the broad-based phenotyping of knockouts through a pipeline comprising 20 disease-oriented platforms.

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The ALK (Anaplastic Lymphoma Kinase) gene encodes a tyrosine kinase receptor preferentially expressed in the central and peripheral nervous systems. A syndromic presentation associating congenital neuroblastoma with severe encephalopathy and an abnormal shape of the brainstem has been described in patients harbouring de novo germline F1174V and F1245V ALK mutations. Here, we investigated the phenotype of knock-in (KI) mice bearing the AlkF1178L mutation (F1174L in human).

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  • Heart failure with preserved ejection fraction (HF-PEF) is a condition that can cause lung problems and usually affects older people with high blood pressure or other risk factors.
  • The researchers studied older rats with high blood pressure to see how their hearts were working using different tests like ECGs and blood pressure measurements.
  • They found that these rats showed signs of heart problems like difficulty relaxing and changes in heart structure, but their heart's ability to pump blood remained okay, making them a good model for future heart medicine studies.
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  • The study analyzes the genetic and phenotypic differences between two mouse inbred strains, C57BL/6J and C57BL/6N, which are widely used in genetic research.
  • Researchers performed comprehensive genome sequence comparisons, identifying coding variants and structural changes that differentiate the two strains, as well as significant phenotypic variations across multiple biological systems.
  • The findings suggest that the identified genetic differences could influence how mutations manifest in these strains, offering potential insights into underlying genetic mechanisms and candidate genes for further investigation.
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Metabolic homeostasis is achieved by complex molecular and cellular networks that differ significantly among individuals and are difficult to model with genetically engineered lines of mice optimized to study single gene function. Here, we systematically acquired metabolic phenotypes by using the EUMODIC EMPReSS protocols across a large panel of isogenic but diverse strains of mice (BXD type) to study the genetic control of metabolism. We generated and analyzed 140 classical phenotypes and deposited these in an open-access web service for systems genetics (www.

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  • TI-VAMP is a protein that helps neurons communicate and grow by fusing their membranes.
  • Scientists deleted a part of the TI-VAMP gene in mice to see what would happen, but the mice didn't show major problems in development or nerve function.
  • However, these special mice had less brain weight and more anxiety, suggesting that TI-VAMP might have a surprising role in how the brain controls feelings and behaviors.
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To identify the genes and pathways that underlie cardiovascular and metabolic phenotypes we performed an integrated analysis of a mouse C57BL/6JxA/J F2 (B6AF2) cross by relating genome-wide gene expression data from adipose, kidney, and liver tissues to physiological endpoints measured in the population. We have identified a large number of trait QTLs including loci driving variation in cardiac function on chromosomes 2 and 6 and a hotspot for adiposity, energy metabolism, and glucose traits on chromosome 8. Integration of adipose gene expression data identified a core set of genes that drive the chromosome 8 adiposity QTL.

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