Project description:Phagocytes in different tissues recognize and remove apoptotic cells via the process of efferocytosis. Although it is well-established that efferocytosis elicits an anti-inflammatory response by phagocytes, the molecules and mechanisms that enforce this response in phagocytes are still being defined. In attempting to decipher gene programs induced after a phagocyte ingests a dying cell, we uncovered a chloride-sensing signaling pathway that controls both the ‘appetite’ of a phagocyte and how a phagocyte responds after corpse uptake. First, we noted that within phagocytes that have ingested a corpse, the solute carrier 12 (SLC12) family members SLC12A2 and SLC12A4 are actively modulated. Interfering with SLC12A2, either genetically or pharmacologically, led to significantly enhanced corpse uptake per phagocyte, while loss of SLC12A4 inhibited corpse uptake. Interestingly, when phagocytes with disrupted SLC12A2 engulfed apoptotic corpses, the typical homeostatic efferocytosis signature was perturbed, characterized by loss of the canonical anti-inflammatory program and replaced by pro-inflammatory and oxidative stress-associated gene programs. In further mechanistic studies, we observed efferocytosis was also regulated by the chloride-sensing pathway upstream of SLC12A2, including the kinases WNK1-OSR1-SPAK, and this involved chloride entry/exit across the plasma membrane of phagocytes during corpse engulfment. We also show that the ‘switch’ to pro-inflammatory sensing of apoptotic cells is specifically due to disruption of the chloride-sensing pathway and not due to corpse overload or poor degradation, and that the pro-inflammatory gene signature can be reversed using a chloride ionophore. Collectively, these data identify the WNK1-OSR1-SPAK-SLC12A2/SLC12A4 chloride-sensing pathway and chloride flux in phagocytes as key modifiers of how a phagocyte interprets an engulfed apoptotic corpse.

2020-03-24 | GSE131860 | GEO

Transcriptome response of Aspergillus fumigatus cultures under different temperatures

Project description:Microarray analysis was used to compare gene expression of Aspergillus fumigatus under two different sporulation temperatures, 17oC and 32oC, with an emphasis on genes encoding known or putative allergens of the fungus. The objective of the study was to investigate whether allergenic potencies of A. fumigatus spores produced under different sporulation temperatures would be influenced by temperature-dependent transcriptional regulation of allergenicity genes. Non-sporulating liquid culture of Aspergillus fumigatus was harvested and divided equally onto two sets of potato dextrose agar plates, one set for incubation at 17oC, the other for incubation at 32oC. After 48 hours of incubation, RNA was harvested from both sets of sporulating cultures, reverse-transcribed into dye-coupled cDNA and hybridized onto microarrays for analysis of gene expression. For each experiment, extracted RNA from the two cultures were hybridized onto two dye-swap technical replicate arrays. A total of three separate experiments were conducted for biological triplicates, for a total of six hybridizations.

2010-05-18 | E-GEOD-16617 | biostudies-arrayexpress

Variations of bacterial community during the decomposition of Microcystis under different temperatures and biomass.

Project description:BACKGROUND:The decomposition of Microcystis can dramatically change the physicochemical properties of freshwater ecosystems. Bacteria play an important role in decomposing organic matters and accelerating the cycling of materials within freshwater lakes. However, actions of the bacterial community are greatly influenced by temperature and the amount of organic matter available to decompose during a bloom. Therefore, it is vital to understand how different temperatures and biomass levels affect the bacterial community during the decomposition of Microcystis. RESULTS:Microcystis addition reduced the diversity of bacterial community. The composition of bacterial community differed markedly between samples with different biomass of Microcystis (no addition, low biomass addition: 0.17 g/L, and high biomass addition: 0.33 g/L). In contrast, temperature factor did not contribute much to the different bacterial community composition. Total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), ammonia nitrogen (NH4+-N) and oxidation-reduction potential (ORP) were the key measured environmental variables shaping the composition of bacterial community. CONCLUSIONS:Decomposition of Microcystis changed the physicochemical characteristics of the water and controlled the diversity and composition of the bacterial community. Microcystis biomass rather than temperature was the dominant factor affecting the diversity and composition of the bacterial community.

| S-EPMC6727399 | biostudies-literature

ChIP-seq for PIF4-HA plants under different temperatures.

Project description:ChIP-seq for PIF4-HA plants under different temperatures.

| PRJNA1013083 | ENA