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Gärtner, F.

Publications and source records attributed to Gärtner, F..

3 recordsLinked to original sources

Morphodynamic domains enable integration of live morphometrics and spatial transcriptomics

Tissue development emerges from the coordinated behaviors of thousands of cells, orchestrated by gene regulatory networks. Recent methodological advances now enable high-resolution live imaging of cell- and tissue-scale dynamics and the construction of spatially resolved gene expression atlases. However, quantitatively linking these modalities remains a central challenge, limiting our ability to understand how gene regulatory networks drive cell- and tissue-scale behaviors. Here, using the Drosophila thorax epithelium as a model system, we introduce an analytical and computational framework based on tissue morphodynamic domains: regions defined by coherent cell and tissue dynamics extracted from live imaging morphometrics. Integrating morphodynamic domains with spatial transcriptomics enables the inference of gene regulatory networks associated with distinct spatial cell- and tissue-level behaviors. Statistical cross-scale analyses further allow the interrogation and validation of gene function, confirming or revealing regulators of specific morphogenetic dynamics. In particular, our framework uncovers a role for the Toll-like receptor Tollo in modulating tissue flow, contraction, and apoptosis. Together, our work establishes a framework that integrates spatial transcriptomics with quantitative, multiscale live morphometrics, providing a generalizable strategy to probe and understand developmental processes.

developmental biology↗

CD5L constraints acute and systemic inflammation and can be a novel potent therapeutic agent against sepsis

The global burden of sepsis, with an estimated 49 million cases and 11 million deaths in 2017, often passes unnoticed to the general public even though it is the direct cause of nearly 20% of all deaths worldwide. This unawareness is perhaps due to misconceptions, or miscoding in the reporting of the ultimate causes of death, as in many diseases it is not the actual infectious agent that causes the biggest harm. Rather, it is the uncontrolled inflammation leading to septic shock that is the most menacing manifestation associated with many infections, and becomes deadly serious once it has passed the stage where anti-microbial drugs no longer have any effect to inactivate or destroy the pathogen. Here we show that the combined anti-bacterial and anti-inflammatory properties of the scavenger receptor cysteine-rich (SRCR) protein CD5L contribute to a remarkable therapeutic effect of the protein to fight sepsis, such that when exogenously administered in C57BL/6 mice with induced lethal-grade sepsis, it can be a very effective curative agent to treat this condition. The resistance conferred by CD5L to polybacterial-induced sepsis using the cecal ligation and puncture (CLP) model is consistent with the reported observations that CD5L physically binds and inactivates diverse species and strains of bacteria. Accordingly, our CD5L-knockout mice are significantly more susceptible to experimentally-induced mid-grade CLP than wild-type animals. We show that CD5L is centered on promoting neutrophil recruitment and activation, overall contributing to reducing the bacteria burden of the animals. However, the dramatic susceptibility of CD5L-deficient animals is not necessarily correlated only with pathogen load, as these mice are also extremely susceptible to sterile sepsis induced by nonlethal doses of LPS. Notwithstanding the observed capacity of CD5L to directly bind to a broad range of pathogens, typical of many PRRs, our evidence suggests that the anti-inflammatory properties of the protein are at least as important as its pathogen-binding potential, and can, and should, be explored to treat the deadly inflammation storm that is sepsis.

immunology↗

Helminth infection-induced carcinogenesis: spectrometric insights from the liver flukes, Opisthorchis and Fasciola

Chronic infections with the flatworm parasites Opisthorchis viverrini, Clonorchis sinensis and Schistosoma haematobium are classified as group 1 biological carcinogens, i.e. definitive causes of cancer. In addition, we reported findings that support the inclusion of Opisthorchis felineus in this list of biological carcinogens. By contrast, infections with close phylogenetic relatives including Fasciola hepatica have not been associated with carcinogenesis. Earlier reports revealed of oxysterol metabolites of Opisthorchis liver fluke origin conjugated with DNA bases, suggesting that the generation of these DNA-adducts may underlie the mutagenicity and carcinogenicity of the infection with these food-borne pathogens. Here we employed liquid chromatography-mass spectrometry (LC-MS/MS) to investigate, compare and contrast spectrograms of soluble extracts from F. hepatica adult worms from bile ducts of cattle with those from O. viverrini and O. felineus from experimentally-infected hamsters. F. hepatica displayed a complex spectrophotometric profile. F. hepatica and Opisthorchis spp. shared several common compounds including oxysterol-like metabolites, bile acids and DNA-adducts, but the spectrometric profiles of these Opisthorchis species included far fewer compounds than F. hepatica. These findings support the postulate that oxysterol-like metabolites of parasite origin can initiate carcinogenesis and they point to a molecular basis for the inconsistencies among major groups of liver flukes concerning infection-induced malignancy.\n\nAuthor SummarySeveral species of trematodes are parasites of the human hepatobiliary tract. Infection with two of these flukes, Clonorchis sinsensis and Opisthorchis viverrini, fresh water fish-borne parasites that occur in East Asia is classified as group 1 carcinogens by the International Agency for Research on Cancer (IARC), i.e. definitive causes of cancer in humans. By contrast, infection with a different liver fluke, Fasciola hepatica, does not lead to malignant transformation of the biliary tract. Given the close phylogeny of all three parasites, this difference in carcinogenicity is intriguing and, if explained, likely of value in novel therapeutic approaches. The importance of the current findings is informative because they present a mass spectrometric analysis and catalog of the similarities and differences between fluke of the genus Opisthorchis and F. hepatica, potentially identifying carcinogenic metabolites of liver fluke origin. These metabolites can be expected to provide deeper understanding of helminth infection induced malignancy.

cancer biology↗