Biology subjects

Villablanca, E. J.

Publications and source records attributed to Villablanca, E. J..

8 recordsLinked to original sources

bioRxiv2026

MAPKAP Kinase-2 signaling enhances the resolution of colonic inflammation through specialized pro-resolving mediators

Failure to resolve acute inflammation contributes to chronic inflammatory diseases, including inflammatory bowel disease, and inflammation associated cancer. MAPKAP kinase-2 (MK2), a stress-activated effector of p38MAPK, is best known for promoting onset and amplification of inflammation through post-transcriptional regulation of cytokines. Here we identify an unexpected role for MK2 in coordinating resolution of intestinal inflammation. Following dextran sodium sulfate induced colonic injury, MK2 deficient mice developed more severe, persistent inflammation, with sustained proinflammatory cytokine and chemokine production, prolonged neutrophil accumulation, and impaired macrophage recruitment during recovery. Myeloid-restricted MK2 deficiency recapitulated the impaired resolution phenotype. Lipid mediator metabololipidomics revealed MK2 deficient colons failed to undergo the transition from pro-inflammatory to pro-resolving lipid mediator production, exhibiting markedly reduced levels of specialized pro-resolving mediators (SPMs), including resolvins and lipoxins. Exogenous SPM administration during the recovery phase restored inflammation resolution in MK2 deficient mice, improving weight, disease activity, and mucosal healing. These findings establish a previously unrecognized role for MK2 in coordinating the transition from inflammatory injury to resolution and repair. Together with our prior finding that myeloid MK2 deficiency reduces colitis-associated tumor progression, these results suggest that inflammation associated tumorigenesis depends not simply on inflammatory injury, but on its coupling to the resolution and tissue repair that follows.

systems biology↗

bioRxiv2023

Longitudinal single-cell data informs deterministic modelling of inflammatory bowel disease

Single-cell mRNA sequencing (scRNA-seq) allows deep molecular and cellular profiling of immunological processes. Longitudinal scRNA-seq datasets can be used for deterministic ordinary differential equation (ODE)-based modelling to mechanistically describe immune dynamics. Here, we derived longitudinal changes in the abundance of six colonic cell types during inflammatory bowel disease (IBD) from scRNA-seq data of a mouse model of colitis using ODE-based models. We then predicted the immune dynamics of a different mouse colitis protocol and confirmed these scRNA-seq-based predictions with our previously published single-cell-based flow cytometry data. We further hypothesised that the estimated model parameters reflect biological processes. We validated this prediction of cellular turnover rates with KI-67 staining and with gene expression information from the scRNA-seq data not used for model fitting. Finally, we tested the translational relevance of the model simulations by predicting genes indicative of treatment response in human IBD patients. The predictive power of IBD deterministic modelling from scRNA-seq data highlights its potential to advance our understanding of immune dynamics in health and disease.

systems biology↗

bioRxiv2023

Golgi organization is a determinant of stem cell function in the small intestine

Cell-to-cell signalling between niche and stem cells regulates tissue regeneration. While the identity of many mediating factors is known, it is largely unknown whether stem cells optimize their receptiveness to niche signals according to the niche organization. Here, we show that Lgr5+ small intestinal stem cells (ISCs) regulate the morphology and orientation of their secretory apparatus to match the niche architecture, and to increase transport efficiency of niche signal receptors. Unlike the progenitor cells lacking lateral niche contacts, ISCs orient Golgi apparatus laterally towards Paneth cells of the epithelial niche, and divide Golgi into multiple stacks reflecting the number of Paneth cell contacts. Stem cells with a higher number of lateral Golgi transported Epidermal growth factor receptor (Egfr) with a higher efficiency than cells with one Golgi. The lateral Golgi orientation and enhanced Egfr transport required A-kinase anchor protein 9 (Akap9), and was necessary for normal regenerative capacity in vitro. Moreover, reduced Akap9 in aged ISCs renders ISCs insensitive to niche-dependent modulation of Golgi stack number and transport efficiency. Our results reveal stem cell-specific Golgi complex configuration that facilitates efficient niche signal reception and tissue regeneration, which is compromised in the aged epithelium.

cell biology↗

bioRxiv2021

The spatial transcriptomic landscape of the healing intestine following damage

The intestinal barrier is composed of a complex cell network defining highly compartmentalized and specialized structures. Here, we use spatial transcriptomics (ST) to define how the transcriptomic landscape is spatially organized in the steady state and healing murine colon. At steady state conditions, we demonstrate a previously unappreciated molecular regionalization of the colon, which dramatically changes during mucosal healing. Here, we identified spatially-organized transcriptional programs defining compartmentalized mucosal healing, and regions with dominant wired pathways. Furthermore, we showed that decreased p53 activation defined areas with increased presence of proliferating epithelial stem cells. Finally, we used our resource to map transcriptomics modules associated with human diseases demonstrating that ST can be used to inform clinical practice. Overall, we provide a publicly available resource defining principles of transcriptomic regionalization of the colon during mucosal healing and a framework to develop and progress further hypotheses.

systems biology↗

bioRxiv2020

Lysophosphatidic acid-mediated GPR35 signaling in CX3CR1+ macrophages regulates the intestinal cytokine milieu

Single nucleotide polymorphisms in the gene encoding G protein-coupled receptor 35 (GPR35) are associated with increased risk of inflammatory bowel disease. However, the mechanism(s) by which GPR35 modulates the intestinal milieu remain undefined. Here we demonstrate in zebrafish and mice that expression of Gpr35 is microbiota-dependent and is enhanced upon inflammation. We identify a GPR35+ colonic macrophage population in mice that is characterized by increased production of pro-inflammatory cytokines, and determine that lysophosphatidic acid (LPA) acts as an endogenous GPR35 ligand to induce Tnf expression. Mice lacking Gpr35 in CX3CR1+ macrophages have aggravated colitis when exposed to dextran sodium sulfate, have decreased transcript levels of the corticosterone-generating gene Cyp11b1, and reduced levels of macrophage-derived TNF. Administration of TNF in these mice restores Cyp11b1 expression and intestinal corticosterone production, and ameliorates DSS-induced colitis. These findings suggest that LPA signals through GPR35 in CX3CR1+ macrophages to control the intestinal cytokine milieu. HighlightsO_LIInflammatory cues and the microbiota modulate Gpr35 expression across species C_LIO_LILPA modulates GPR35-dependent functions in zebrafish and mice macrophages C_LIO_LIGPR35 expressing macrophages have a protective role during intestinal inflammation C_LIO_LIGPR35 control intestinal inflammation by inducing TNF and corticosterone synthesis C_LI eTOC BlurbGPR35 have been associated with IBD, but how GPR35 may influence macrophage-mediated intestinal homeostasis remains unclear. Using zebrafish and mice genetic tools, Niess, Villablanca, and colleagues have identified that LPA triggers GPR35 activity, and loss of macrophage GPR35 signaling confers intrinsic dysfunctions with effects on cytokine production and intestinal homeostasis.

immunology↗

bioRxiv2019

Liver X Receptor regulates Th17 and RORγt+ Treg cells by distinct mechanisms

The gastrointestinal microenvironment, dominated by dietary compounds and the commensal bacteria, is a major driver of intestinal CD4+ T helper (Th) cell differentiation. Dietary compounds can be sensed by nuclear receptors (NRs) that consequently exerts pleiotropic effects including immune modulation. However, how NRs regulate distinct intestinal Th subsets remain poorly understood. Here, we found that under homeostatic condition Liver X receptor (LXR), a sensor of cholesterol metabolites, controls ROR{gamma}t+ Treg and Th17 cells in the intestine draining mesenteric lymph node (MLN). Mechanistically, while lack of LXR signaling in CD11c+ myeloid cells led to an increase in ROR{gamma}t+ Treg, modulation of MLN Th17 was independent of LXR signaling in either immune or epithelial cells. Of note, LXR modulated only the Th17 cells, but not ROR{gamma}t+ Treg in the MLN and horizontal transfer of microbiota between LXR-/- and WT mice was sufficient to partially increase the MLN Th17 in WT mice. While LXR deficiency increased the abundance of Ruminococcaceae and Lachnospiraceae bacterial families compared to the WT littermates, microbiota ablation including ablation of SFB was not sufficient to dampen LXR-mediated expansion of MLN Th17. Altogether, our results suggest that LXR modulates ROR{gamma}t+ Treg and Th17 cells in the MLN through distinct mechanisms.

immunology↗

bioRxiv2019

Conserved transcriptomic profile between mouse and human colitis allows temporal dynamic visualization of IBD-risk genes and unsupervised patient stratification

AbstrasctDespite the fact that ulcerative colitis (UC) patients show heterogeneous clinical manifestation and diverse response to biological therapies, all UC patients are classified as one group. Therefore, there is a lack of tailored therapies. In order to design these, an unsupervised molecular re-classification of UC patients is evoked. Classical clustering approaches based on tissue transcriptomic data were not able to classify UC patients into subgroups, likely due to associated covariates. In addition, while genome wide association studies (GWAS) have identified potential new target genes, their temporal dynamic revealing the optimal therapeutic window of time remains to be elucidated. To overcome the limitations, we generated time-series transcriptome data from a mouse model of colitis, which was then cross-compared with human datasets. This allowed us to visualize IBD-risk gene expression kinetics and reveal that the expression of the majority of IBD-risk genes peak during the inflammatory phase, and not the recovery phase. Moreover, by restricting the analysis to the most differentially expressed genes shared between mouse and human, we were able to cluster UC patients into two subgroups, termed UC1 and UC2. We found that UC1 patients expressed higher copy of genes involved in neutrophil recruitment, activation and degranulation compared to UC2. Of note, we found that over 87% of UC1 patients failed to respond to two of the most widely-used biological therapies for UC.\n\nThis study serves as a proof of concept that cross-species comparison of gene expression profiles enables the temporal annotation of disease-associated gene expression and the stratification of patients as of yet considered molecularly undistinguishable.

immunology↗

bioRxiv2017

Generation of Mouse-Zebrafish Hematopoietic Tissue Chimeric Embryos for Hematopoiesis and Host-Pathogen Interaction Studies

Xenografts of the hematopoietic system are extremely useful as disease models and for translational research. Zebrafish xenografts have been widely used to monitor blood cancer cell dissemination and homing due to the optical clarity of embryos and larvae, which allow unrestricted in vivo visualization of migratory events. To broaden the scope of xenotransplantation studies in zebrafish, we have developed a technique that transiently generates hematopoietic tissue chimeras by transplanting murine bone marrow cells into zebrafish blastulae. This procedure leads to mammalian cell integration into the fish developmental hematopoietic program. Monitoring zebrafish chimeras at different time points post fertilization using in vivo time-lapse and confocal imaging showed murine cell co-localization with developing primitive and definitive hematopoietic tissues, intravasation into fish circulation, and dynamic hematopoietic cell-vascular endothelial and hematopoietic cell-niche interactions. Immunohistochemistry assays performed in chimeric animals showed that, after engraftment, murine cells expressed antigens related to i) hematopoietic stem and progenitor cells, ii) active cell proliferation, and iii) myeloid cell lineages. Lastly, xenografted zebrafish larvae infected with Klebsiella pneumoniae showed murine immune cells trafficking to bacterial foci and interacting with bacterial cells. Overall, these results show that mammalian bone marrow cells xenografted in zebrafish integrate into the host hematopoietic system revealing highly conserved molecular mechanisms of hematopoiesis between zebrafish and mammals. In addition, this procedure introduces a useful and simple method that improves and broadens the scope of hematopoietic tissue xenotransplantation studies in zebrafish.

developmental biology↗