Apostolova, I. | bioRxiv Science

bioRxiv2022

Heritage of ancient cultures supports conservation: a continent-wide perspective from the Eurasian steppes

Civilisations including ancient ones, have shaped the global ecosystems in many ways through a co-evolution of landscapes and humans. However, the cultural legacies of ancient and lost civilisations are seldom considered in conservation. Here using a continental-scale dataset containing over 1,000 data records on the localities, land cover, protection status and cultural values related to ancient steppic burial mounds (so-called kurgans), we evaluated how these iconic and widespread landmarks can contribute to grassland conservation in the Eurasian steppes, which is one of the most endangered biomes on Earth. By using Bayesian logistic generalized regressions and proportional odds logistic regressions, we aimed to reveal the potential of mounds in preserving grasslands considering landscapes with different levels of land use transformation. We also compared the conservation potential of mounds situated inside and outside protected areas and assessed whether the presence of cultural, historical or spiritual values support the maintenance of grasslands on them. We revealed that kurgans have enormous importance in preserving grasslands in transformed landscapes outside protected areas, where they can act as habitat islands, and provide an additional pillar for conservation by contributing to habitat conservation and improvement of habitat connectivity. We found that besides their steep slopes hindering ploughing, the existence of cultural, historical or religious values could almost double the chance for grassland occurrence on kurgans due to the related extensive land use and the respect of local communities. As the estimated number of steppic mounds is about 600,000 and also similar historical features exist in all continents, our results can be upscaled to a global level. Our results also suggest that an integrative socio-ecological approach in conservation might support the positive synergistic effects of conservational, landscape and cultural values.

ecology↗

bioRxiv2018

Non-canonical HIF-1 stabilization is essential for intestinal tumorigenesis

The hypoxia-inducible transcription factor HIF-1 is appreciated as a promising target for cancer therapy. However, conditional deletion of HIF-1 and HIF-1 target genes in cells of the tumor microenvironment can result in accelerated tumor growth, calling for a detailed characterization of the cellular context to fully comprehend HIF-1s role in tumorigenesis. We dissected cell type-specific functions of HIF-1 for intestinal tumorigenesis by lineage-restricted deletion of the Hif1a locus. Intestinal epithelial cell-specific Hif1a loss reduced activation of wnt/{beta}-catenin, tumor-specific metabolism and inflammation, significantly inhibiting tumor growth. Deletion of Hif1a in myeloid cells reduced the expression of fibroblast-activating factors in tumor-associated macrophages resulting in decreased abundance of tumor-associated fibroblasts and robustly reduced tumor formation. Interestingly, hypoxia was detectable only sparsely and without spatial association with nuclear HIF-1 in intestinal adenomas, pointing towards a functional importance of hypoxia-independent, i.e. non-canonical HIF-1 stabilization that has not been previously appreciated. This adds a further layer of complexity to the regulation of HIF-1 and suggests that hypoxia and HIF-1 stabilization can be uncoupled in cancer. Collectively, our data show that HIF-1 is a pivotal pro-tumorigenic factor for intestinal tumor formation, controlling key oncogenic programs in both the epithelial tumor compartment and the tumor microenvironment.

cancer biology↗