Earlier vegetation greening under climate change raises evapotranspiration and thus lowers spring soil moisture, yet the extent and magnitude of this water deficit persistence into the following summer remain elusive. We provide observational evidence that increased foliage cover over the Northern Hemisphere, during 1982–2011, triggers an additional soil moisture deficit that is further carried over into summer. Climate model simulations independently support this and attribute the driving process to be larger increases in evapotranspiration than in precipitation. This extra soil drying is projected to amplify the frequency and intensity of summer heatwaves. Most feedbacks operate locally, except for a notable teleconnection where extra moisture transpired over Europe is transported to central Siberia. Model results illustrate that this teleconnection offsets Siberian soil moisture losses from local spring greening. Our results highlight that climate change adaptation planning must account for the extra summer water and heatwave stress inherited from warming-induced earlier greening.
Highlights d Generation of salt-induced calcium signal requires downstream targets in Arabidopsis d AtANNEXIN4 is involved in controlling calcium transients d SOS2 phosphorylates AtANN4 under salt stress, which alters calcium signatures d A negative feedback loop fine-tunes calcium signal and optimizes plant salt response
Despite increasing knowledge regarding melanoma-initiating cells (MICs), questions persist regarding the number and phenotypic nature of cells with tumor-generating capability. Evidence for a phenotypically distinct human MIC has been found in NOD/SCID (non-obese diabetic/severe combined immunodeficiency) mice. However, a phenotypically distinct human MIC was not found in the NOD/SCIDIl2rg−/− (NSG) mouse model. The demonstration of a distinct population of human melanoma cells responsible for tumorigenesis and tumor cell self-renewal would provide an important target for new melanoma therapies. In this study, we show a 100-fold range in MIC frequency in human melanoma (1 in 18,000 to 1 in 1,851,000 cells) in the NOD/SCID mouse. In this model, human melanoma cells with high aldehyde dehydrogenase (ALDH) activity were enriched 16.8-fold in tumorigenic cells over unfractionated (UNF) cells, such that 1 in 21,000 cells was a MIC. In the NSG mouse, the ALDH expressing cell population was enriched 100-fold in tumorigenic cells over UNF cells, such that one in four cells was a MIC. Xenograft melanomas that developed from ALDH+ cells displayed robust self-renewal, whereas those from ALDH− cells showed minimal self-renewal in vitro. Thus, ALDH+ melanoma cells have enhanced tumorigenicity over ALDH− cells and superior self-renewal ability.
ApoE is expressed in multiple mammalian cell types in which it supports cellular differentiated function. In this report we demonstrate that apoE expression in adipocytes is regulated by factors involved in modulating systemic insulin sensitivity. Systemic treatment with pioglitazone increased systemic insulin sensitivity and increased apoE mRNA levels in adipose tissue by 2-3-fold. Treatment of cultured 3T3-L1 adipocytes with ciglitazone increased apoE mRNA levels by 2-4-fold in a dose-dependent manner and increased apoE secretion from cells. Conversely, treatment of adipocytes with tumor necrosis factor (TNF) ␣ reduced apoE mRNA levels and apoE secretion by 60%. Neither insulin nor a peroxisome proliferator-activated receptor (PPAR) ␣ agonist regulated adipocyte apoE gene expression. In addition, treatment of human monocyte-derived macrophages with ciglitazone did not regulate expression of apoE. Additional analyses using reporter genes indicated that the effect of TNF␣ and PPAR␥ agonists on the apoE gene was mediated via distinct gene control elements. The TNF␣ effect was mediated by elements within the proximal promoter, whereas the PPAR␥ effect was mediated by elements within a downstream enhancer. However, the addition of TNF␣ substantially reduced the absolute levels of apoE reporter gene response even in the presence of ciglitazone. These results indicate for the first time that adipose tissue expression of apoE is modulated by physiologic regulators of insulin sensitivity.
The properties of quantum materials are commonly tuned using experimental variables such as pressure, magnetic field and doping. Here we explore a different approach: irreversible, plastic deformation of single crystals. We show for the archetypal unconventional superconductor SrTiO3 that compressive plastic deformation induces lowdimensional superconductivity significantly above the superconducting transition temperature (Tc) of undeformed samples. We furthermore present evidence for unusual normal-state transport behaviour that suggests superconducting correlations at temperatures two orders of magnitude above the bulk Tc. The superconductivity enhancement is correlated with the appearance of structural features related to selforganized dislocation structures, as revealed by diffuse neutron and X-ray scattering.These results suggest that deformed SrTiO3 is a potential high-temperature superconductor, and push the limits of superconductivity in this low-density electronic system. More broadly, we demonstrate the promise of plastic deformation and dislocation engineering as tools to manipulate electronic properties of quantum materials.
Cells with aldehyde dehydrogenase activity (ALDH+) are the most tumorigenic cells in many cancers, including melanoma, making ALDH a candidate therapeutic target. We examined the effects of chemical inhibition of ALDH1 on the response of human melanoma xenografts to chemotherapy and the effects of ALDH1A1 RNA silencing on melanoma growth and metastasis. Addition of ALDH1 inhibitors (e.g. diethylaminobenzaldehyde) to dacarbazine chemotherapy, not only reduced tumor growth in vivo, but also resulted in a significant decrease in the number of residual cells capable of tumorigenesis. shRNA depletion of ALDH1A1 in melanoma cells resulted not only in a significant delay in appearance of xenograft melanomas and reduction in growth, but also significantly decreased the number of metastases and metastatic burden after lateral tail vein injections in mice. In summary, ALDH1 inhibition in combinatorial therapy with dacarbazine reduced the number of residual tumorigenic cells post-therapy and ALDH1A1 depletion had marked inhibitory effects on both melanoma growth and metastasis. These findings suggest that ALDH1 inhibition may not only be able to provide a therapeutic advantage in melanoma treatment, but may also prevent rapid relapse after therapy, as residual tumorigenic cells are fewer and metastatic ability is diminished.
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