3 research outputs found
Transcriptomic, biochemical and individual markers in transplanted Daphnia magna to characterize impacts in the field
Daphnia magna individuals were transplanted across 12 sites from three Spanish river basins (Llobregat, Ebro,
Jucar) showing different sources of pollution. Gene transcription, feeding and biochemical responses in the field
were assessed and comparedwith those obtained in re-constitutedwater treatments spikedwith organic eluates
obtained fromwater samples collected at the same locations and sampling periods. Up to 166 trace contaminants
were detected in water and classified by their mode of action into 45 groups that included metals, pharmaceuticals,
pesticides, illicit drugs, and other industrial compounds. Physicochemical water parameters differentiated
the three river basins with Llobregat having the highest levels of conductivity, metals and pharmaceuticals,
followed by Ebro, whereas the Jucar river had the greatest levels of illicit drugs. D. magna grazing rates and cholinesterase
activity responded similarly than the diversity of riparian benthic communities. Transcription patterns
of 13 different genes encoding for general stress, metabolismand energy processes,molting and xenobiotic transporters
corroborate phenotypic responses differentiated siteswithin and across river basins. Principal Component
Analysis and Partial Least Square Projections to Latent Structures regression analyses indicated that measured in
situ responses ofmost genes and biomarkers and that of benthicmacroinvertebrate diversity indexeswere affected
by distinct environmental factors. Conductivity, suspended solids and fungicideswere negatively relatedwith
the diversity of macroinvertebrates cholinesterase, and feeding responses. Gene transcripts of heat shock protein
and metallothionein were positively related with 11 classes of organic contaminants and 6 metals. Gene transcripts
related with signaling paths of molting and reproduction, sugar, protein and xenobiotic metabolism
responded similarly in field and lab exposures and were related with high residue concentrations of analgesics,
diuretics, psychiatric drugs, β blockers, illicit drugs, trizoles, bisphenol A, caffeine and pesticides. These results indicate
that application of omic technologies in the field is a promising subject in water management
Endothelial cell rearrangements during vascular patterning require PI3-kinase-mediated inhibition of actomyosin contractility
Angiogenesis is a dynamic process relying on endothelial cell rearrangements within vascular tubes, yet the underlying mechanisms and functional relevance are poorly understood. Here we show that PI3Kα regulates endothelial cell rearrangements using a combination of a PI3Kα-selective inhibitor and endothelial-specific genetic deletion to abrogate PI3Kα activity during vessel development. Quantitative phosphoproteomics together with detailed cell biology analyses in vivo and in vitro reveal that PI3K signalling prevents NUAK1-dependent phosphorylation of the myosin phosphatase targeting-1 (MYPT1) protein, thereby allowing myosin light chain phosphatase (MLCP) activity and ultimately downregulating actomyosin contractility. Decreased PI3K activity enhances actomyosin contractility and impairs junctional remodelling and stabilization. This leads to overstretched endothelial cells that fail to anastomose properly and form aberrant superimposed layers within the vasculature. Our findings define the PI3K/NUAK1/MYPT1/MLCP axis as a critical pathway to regulate actomyosin contractility in endothelial cells, supporting vascular patterning and expansion through the control of cell rearrangement
Endothelial cell rearrangements during vascular patterning require PI3-kinase-mediated inhibition of actomyosin contractility
Angiogenesis is a dynamic process relying on endothelial cell rearrangements within vascular tubes, yet the underlying mechanisms and functional relevance are poorly understood. Here we show that PI3Kα regulates endothelial cell rearrangements using a combination of a PI3Kα-selective inhibitor and endothelial-specific genetic deletion to abrogate PI3Kα activity during vessel development. Quantitative phosphoproteomics together with detailed cell biology analyses in vivo and in vitro reveal that PI3K signalling prevents NUAK1-dependent phosphorylation of the myosin phosphatase targeting-1 (MYPT1) protein, thereby allowing myosin light chain phosphatase (MLCP) activity and ultimately downregulating actomyosin contractility. Decreased PI3K activity enhances actomyosin contractility and impairs junctional remodelling and stabilization. This leads to overstretched endothelial cells that fail to anastomose properly and form aberrant superimposed layers within the vasculature. Our findings define the PI3K/NUAK1/MYPT1/MLCP axis as a critical pathway to regulate actomyosin contractility in endothelial cells, supporting vascular patterning and expansion through the control of cell rearrangement