Biology subjects

Marques, E.

Publications and source records attributed to Marques, E..

4 recordsLinked to original sources

bioRxiv2025

An inherited mtDNA mutation remodels inflammatory cytokine responses in macrophages and in vivo

Impaired mitochondrial bioenergetics in macrophages can drive hyperinflammatory cytokine responses1-6, but whether this may also be caused by inherited mtDNA mutations is unknown. Here, we address this question using a multi-omic approach that integrates super-resolution imaging and metabolic analyses to profile macrophages from a mouse model of mitochondrial disease arising from a heteroplasmic mutation (m.5019A>G) in the mitochondrial tRNA for alanine7. These m.5019A>G macrophages exhibit defects in respiratory chain complexes and oxidative phosphorylation (OxPhos) due to decreased intra-mitochondrial translation. To adapt to this metabolic stress, mitochondrial fusion, reductive glutamine metabolism, and aerobic glycolysis are all increased. Upon inflammatory activation, type I interferon (IFN-I) release is enhanced, while the production of pro-inflammatory cytokines and oxylipins are restrained in m.5019A>G macrophages. Finally, an in vivo endotoxemia model using m.5019A>G mice reveal elevated IFN-I levels and sickness behaviour. In conclusion, our study identifies an unexpected imbalance in innate immune signalling in response to a pathogenic mtDNA mutation, with important implications for the progression of pathology in patients with mtDNA diseases8.

immunology↗

bioRxiv2024

Lcn2 protects from cisplatin induced AKI by regulating DNA damage response via EGFR activation

BackgroundLipocalin 2 (Lcn2), a small-secreted protein, is an established sensitive biomarker of kidney injury. In Cisplatin (CDDP) induced acute kidney injury (AKI), Lcn2 expression is swiftly and strongly increased in suffering renal medullary tubules. While recent reports correlates Lcn2 expression in cancer cells with CDDP resistance, the role of Lcn2 in kidney tubule damaged by CDDP remains unknown. MethodsTo better understand the role of Lcn2 in CDDP-induced AKI, experiments on Lcn2+/+ or Lcn2-/- mice as well as immortalized kidney cells knock-down (KD) for Lcn2 were conducted. Kidney function and injury were assessed using standard techniques. Cellular and molecular mechanisms were studied in WT and Lcn2 KD cells in combination with pathways inhibitors in order to gain insight Lcn2 driven mechanisms. ResultsIn animal injected with CDDP, Lcn2 was upregulated mostly in kidney inner medulla collecting duct while it was reabsorbed in the proximal tubules. Lcn2-/- in mice significantly decreased kidney function compare to WT mice, while it increased parenchymal damage due to increased cell death and cast formation. Interestingly, while little to no damage were present in the medulla of CDDP injected WT animal, a clear increase of medulla tubular lesions was observed in Lcn2-/- mice. Using Inner Medullary Collecting Duct cells (mIMDC-3), we showed that Lcn2 KD induces a p53-dependent apoptosis upon Cisplatin exposure while no effect on necrosis was observed. Finally, we demonstrated that Lcn2 drives CDDP resistance to apoptosis through the activation of the pro-survival EGFR pathway. ConclusionsWe established that Lcn2 is a renoprotective protein in CDDP-induced AKI via the activation of EGFR pathway. This new mechanism might represent a new approach for the treatment of AKI.

cell biology↗

bioRxiv2020

Hypothetical Human Immune Genome Complex Gradient May Help To Explain The Congenital Zika Symdrome Catastrophe In Brazil: A New Theory

There are few data considering human genetics as an important risk factor for birth abnormalities related to ZIKV infection during pregnancy, even though sub-Saharan African populations are apparently more resistant to CZS as compared to populations in the Americas. We hypothesized that single nucleotide variants (SNVs), especially in innate immune genes, could make some populations more susceptible to Zika congenital complications than others. Differences in the SNV frequencies among continental populations provide great potential for Machine Learning techniques. We explored a key immune genomic gradient between individuals from Africa, Asia and Latin America, working with complex signatures, using 297 SNVs. We employed a two-step approach. In the first step, decision trees (DTs) were used to extract the most discriminating SNVs among populations. In the second step, machine learning algorithms were used to evaluate the quality of the SNV pool identified in step one for discriminating between individuals from sub-Saharan African and Latin-American populations. Our results suggest that 10 SNVs from 10 genes (CLEC4M, CD58, OAS2, CD80, VEPH1, CTLA4, CD274, CD209, PLAAT4, CREB3L1) were able to discriminate sub-Saharan Africans from Latin American populations using only immune genome data, with an accuracy close to 100%. Moreover, we found that these SNVs form a genome gradient across the three main continental populations. These SNVs are important elements of the innate immune system and in the response against viruses. Our data support the Human Immune Genome Complex Gradient hypothesis as a new theory that may help to explain the CZS catastrophe in Brazil.

genetics↗

bioRxiv2018

Multiple independent adaptations to different ranges of host plants indicate high adaptability despite clonal reproduction in the nematode pest Meloidogyne incognita

The most devastating nematodes to worldwide agriculture are the root-knot nematodes with Meloidogyne incognita being the most widely distributed and damaging species. This parasitic and ecological success seem surprising given its supposed obligatory clonal reproduction. Clonal reproduction has been suspected based on cytological observations but, so far, never confirmed by population genomics data. At the species level, M. incognita is highly polyphagous with thousands of host plants. However, the host range varies among different M. incognita isolates that may present distinct and more restricted host compatibilities. Historically, four host races had been defined as a function of ranges of compatible and incompatible plants. We sequenced the genomes of 11 isolates across Brazil, covering these four distinct races to assess (i) how clonal reproduction is and (ii) how the level of genome variability associates with biological traits such as the host races, affected agronomic culture, and geographical distribution. By aligning the genomic reads of the isolates to the M. incognita reference genome assembly, we identified SNV and small-scale insertions/deletions. Analysis of linkage disequilibrium and 4-gametes test, showed no sign of recombination, confirming the clonal mode of reproduction of M. incognita. We showed that there are relatively few point variations between the different isolates, and these variations show no significant association with either the host races, the geographical origin of the samples or the host plant on which they have been collected. Due to the lack of phylogenetic signal underlying their existence, we recommend the discontinuation of the terminology race. Overall, these results suggest that multiple gains and losses of parasitic abilities and adaptations to different environmental conditions account for the broad host spectrum and wide geographic distribution of M. incognita. Hence, this nematode constitutes a model species to study adaptability without sexual recombination and overall low genomic variations in animals.

evolutionary biology↗