Modeling individual-tree mortality in Pyrenean oak (Quercus pyrenaica Willd.) stands

International audienceTree mortality is an important process in forest ecosystem dynamics and is one of the least understood phenomena, because of the complex interactions between different environmental stresses, minimal understanding of whole-plant mortality processes, and a chronic shortage of data. * A multilevel logistic regression model was developed for predicting the probability of mortality in individual trees with the objective of improving long-term planning in Spanish pyrenean oak forests. The data came from one 10-year re-measurement of the permanent plot network belonging to the Spanish National Forest Inventory distributed throughout north-west Spain. * The probability of mortality decreased with increasing individual diameter at breast height and increasing ratio of the height of subject tree to the dominant height of the sample plot. The resulting mortality model was evaluated using an independent data set from a region close to the study area. * The regeneration of pyrenean oak generally takes place through stump and/or root sprouting; so stand dynamics differ from those of others species. The model developed is expected to improve the accuracy of stand forecasts in northwest Spain

Estimation of plant diversity at landscape level A methodological approach applied to three Spanish rural areas

Approaches linking biodiversity assessment with landscape structure are necessary in the framework of sustainable rural development. The present paper describes a methodology to estimate plant diversity involving landscape structure as a proportional weight associated with different plant communities found in the landscape mosaic. The area occupied by a plant community, its patch number or its spatial distribution of patches are variables that could be expressed in gamma plant diversity of a territory. The methodology applies (1) remote sensing information, to identify land cover and land use types; (2) aspect, to discriminate composition of plant communities in each land cover type; (3) multi-scale field techniques, to asses plant diversity; (4) affinity analysis of plant community composition, to validate the stratified random sampling design and (5) the additive model that partitions gamma diversity into its alpha and beta components. The method was applied to three Spanish rural areas and was able to record 150-260 species per ha. Species richness, Shannon information index and Simpson concentration index were used to measure diversity in each area. The estimation using Shannon diversity index and the product of patch number and patch interspersion as weighting of plant community diversity was found to be the most appropriate method of measuring plant diversity at the landscape level. © 2004 Kluwer Academic Publishers

Estimation of Plant Diversity at Landscape Level: A Methodological Approach Applied to Three Spanish Rural Areas

Approaches linking biodiversity assessment with landscape structure are necessary in the framework of sustainable rural development. The present paper describes a methodology to estimate plant diversity involving landscape structure as a proportional weight associated with different plant communities found in the landscape mosaic. The area occupied by a plant community, its patch number or its spatial distribution of patches are variables that could be expressed in gamma plant diversity of a territory. The methodology applies (1) remote sensing information, to identify land cover and land use types; (2) aspect, to discriminate composition of plant communities in each land cover type; (3) multi-scale field techniques, to asses plant diversity; (4) affinity analysis of plant community composition, to validate the stratified random sampling design and (5) the additive model that partitions gamma diversity into its alpha and beta components. The method was applied to three Spanish rural areas and was able to record 150–260 species per ha. Species richness, Shannon information index and Simpson concentration index were used to measure diversity in each area. The estimation using Shannon diversity index and the product of patch number and patch interspersion as weighting of plant community diversity was found to be the most appropriate method of measuring plant diversity at the landscape level.Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu

Upregulation of NOR-1 in calcified human vascular tissues: impact on osteogenic differentiation and calcification

Cardiovascular calcification is a significant public health issue whose pathophysiology is not fully understood. NOR-1 regulates critical processes in cardiovascular remodeling, but its contribution to ectopic calcification is unknown. NOR-1 was overexpressed in human calcific aortic valves and calcified atherosclerotic lesions colocalizing with RUNX2, a factor essential for osteochondrogenic differentiation and calcification. NOR-1 and osteogenic markers were upregulated in calcifying human valvular interstitial cells (VICs) and human vascular smooth muscle cells (VSMCs). Gain- and loss-of-function approaches demonstrated that NOR-1 negatively modulates the expression of osteogenic genes relevant for the osteogenic transdifferentiation (RUNX2, IL-6, BMP2, and ALPL) and calcification of VICs. VSMCs from transgenic mice overexpressing NOR-1 in these cells (TgNOR-1VSMC) expressed lower basal levels of osteogenic genes (IL-6, BMP2, ALPL, OPN) than cells from WT littermates, and their upregulation by a high-phosphate osteogenic medium (OM) was completely prevented by NOR-1 transgenesis. Consistently, this was associated with a dramatic reduction in the calcification of both transgenic VSMCs and aortic rings from TgNOR-1VSMC mice exposed to OM. Atherosclerosis and calcification were induce in mice by the administration of AAV-PCSK9D374Y and a high-fat/high-cholesterol diet. Challenged-TgNOR-1VSMC mice exhibited decreased vascular expression of osteogenic markers, and both less atherosclerotic burden (assessed in whole aorta and lesion size in aortic arch and brachiocephalic artery) and less vascular calcification (assessed either by near-infrared fluorescence imaging or histological analysis) than WT mice. Our data indicate that NOR-1 negatively modulates the expression of genes critically involved in the osteogenic differentiation of VICs and VSMCs, thereby restraining ectopic cardiovascular calcification.This work was supported by the Spanish Ministerio de Ciencia e Innovación ( RTI2018-094727-B-100 and PID2021-122509OB-I00 funded by MCIN/ AEI/10.13039/501100011033 and by “ERDF A way of making Europe”), Instituto de Salud Carlos III (ISCIII; Spain) ( PI21/01048 ), and Sociedad Española de Arteriosclerosis ( SEA-2022 ). C.B-S and L.P-U were supported by a FPU (Ministerio de Universidades; Spain), and PFIS fellowships, respectively.Peer reviewe

Role of KRAS^A146T mutation on downstream pathway and hnRNP acetylation.

<p><b>A</b>. HAF1 cells were treated with EGF in the presence or absence of MAPK inhibitors (MEK, UO0126 or PI3KA, LY294002). Protein extracts from HAF1 cells were immunoprecipitated with α-hnRNPA1 or hnRNPL antibodies. The immunoprecipitated samples were then analyzed by western blot with antibodies recognizing acetyl-lysine residues and, either hnRNPA1 or hnRNPL (Left panel). Phosphorylation of ERK1/2 and AKT in HAF1 cells was also assessed to confirm efficiency of individual inhibitors at doses used (Right panel). <b>B</b>. Both MAPK inhibitors were simultaneously used to study their effect on EGF-induced acetylation of hnRNPs. <b>C</b>. Role of deacetylases on basal acetylation levels of hnRNPs were further studied in HAF1 cells treated with trichostatin A. Immunoprecipitation with hnRNPs antibodies and western blot against acetyl-lysine, hnRNPA1 or L in HAF1 cells treated with EGF, TSA or a combination of both are shown.</p

EGF-Induced Acetylation of Heterogeneous Nuclear Ribonucleoproteins Is Dependent on <i>KRAS</i> Mutational Status in Colorectal Cancer Cells

<div><p><i>KRAS</i> mutational status is considered a negative predictive marker of the response to anti-EGFR therapies in colorectal cancer (CRC) patients. However, conflicting data exist regarding the variable response to EGFR-targeted therapy. The effects of oncogenic <i>KRAS</i> on downstream targets were studied in cell lines with different <i>KRAS</i> mutations. Cells harboring a single <i>KRAS^G13D</i> allele showed the most tumorigenic profile, with constitutive activation of the downstream pathway, rendering them EGF-unresponsive. Conversely, <i>KRAS^A146T</i> cells showed a full EGF-response in terms of signal transduction pathways, cell proliferation, migration or adhesion. Moreover, the global acetylome of CRC cells was also dependent on <i>KRAS</i> mutational status. Several hnRNP family members were identified within the 36 acetylated-proteins. Acetylation status is known to be involved in the modulation of EGF-response. In agreement with results presented herein, hnRNPA1 and L acetylation was induced in response to EGF in <i>KRAS^A146T</i> cells, whereas acetyl-hnRNPA1 and L levels remained unchanged after growth factor treatment in <i>KRAS^G13D</i> unresponsive cells. Our results showed that hnRNPs induced-acetylation is dependent on KRAS mutational status. Nevertheless hnRNPs acetylation might also be the point where different oncogenic pathways converge.</p></div

Gene expression profile from Microarray data analysis.

<p>Total RNA from CRC cells cultured in basal conditions with 10% FBS was analyzed by microarray. <b>A</b>. Venn-diagram showing the percentage of up- and down-regulated genes found in the cell line harboring a <i>KRAS</i>^<i>G13D</i> mutation (HAE6), when compared to mRNA levels found in HAF1 cells (<i>KRAS</i>^<i>A146T</i><i>)</i>. <b>B</b>. Bar chart representing differentially expressed genes (p-value ≤ 0.001) among the two cell lines HAE6 <i>versus</i> HAF1 cells, considering only-log2 fold change >1.5 and <-1.5. Gene symbol for each gene is indicated on the left. <b>C</b>. Three genes, <i>CATHEPSIN L</i>, <i>CATHEPSIN C</i> and <i>ADAM19</i> were selected based on their potential role on cell invasion and migration, for microarray validation using qPCR. *P< 0.05 versus HAF1 cells.</p