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Dahlgren, J.

Publications and source records attributed to Dahlgren, J..

2 recordsLinked to original sources

Gene expression signatures predict response to therapy with growth hormone

Recombinant human growth hormone (r-hGH) is used as a therapeutic agent for disorders of growth including growth hormone deficiency (GHD) and Turner syndrome (TS). Treatment is costly and current methods to model response can only account for up to 60% of the variance. The aim of this work was to take a novel genomic approach to growth prediction. GHD (n=71) and TS patients (n=43) were recruited in a study on the long term response to r-hGH over five years of therapy. Pharmacogenomic analysis was performed using 1219 genetic markers and baseline blood transcriptome. Random forest was used to determine predictive value of transcriptomic data associated with growth response. No genetic marker passed the stringency criteria required for predictive value. However, we demonstrated that transcriptomic data can be used to predict growth with a high accuracy (AUC > 0.9) for short and long term therapeutic response in GHD and TS. Network models identified an identical core set of genes in both GHD and TS at each year of therapy whose expression can be used to classify therapeutic response to r-hGH. Combining transcriptomic markers with clinical phenotype was shown to significantly reduce predictive error. We have characterised the utility of baseline transcriptome for the prediction of growth response including the identification of a set of common genes in GHD and TS. This work could be translated into a single genomic test linked to a prediction algorithm to improve clinical management. One Sentence SummaryA blood transcriptome signature predicts response to recombinant human growth hormone in both growth hormone deficient and Turner syndrome children Trial registration numbers: NCT00256126 & NCT00699855

clinical trials

Similar patterns of background mortality across Europe are mostly driven by drought in European beech and a combination of drought and competition in Scots pine.

AimBackground tree mortality is a complex demographic process that affects forest structure and long-term dynamics. We aimed to test how drought intensity interacts with interspecific and intraspecific competition (or facilitation) in shaping individual mortality patterns across tree species ranges. LocationEuropean latitudinal gradient (Spain to Finland). Time period1985 - 2014. Major taxa studiedScots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.). MethodsWe performed logistic regression models based on individual tree mortality recorded in five European National Forest Inventories. We computed the relative importance of climatic drought intensity, basal area of conspecific and heterospecific trees (proxy of indirect intra- and interspecific competition or facilitation) and the effects of their interactions on mortality along the latitudinal gradient of both species range. ResultsIncrease in drought intensity over the study period was associated with higher mortality rates in both species. Drought was the most important driver of beech mortality at almost all latitudes while Scots pine mortality was mainly driven by basal area. High conspecific basal area was associated with high mortality rates in both species while high heterospecific basal area was correlated with mortality rates that were high in Scots pine but low in beech. Main conclusionsBeech mortality was directly affected by drought while Scots pine mortality was indirectly affected by drought through interactions with basal area. Despite their different sensitivity to drought and basal area, the highest predicted mortality rates for both species were at the ecotone between Mediterranean and cool temperate biomes, which can be explained by the combined effect of drought and competition. In the context of global warming, which is expected to be particularly strong in the Mediterranean biome, our results suggest that populations at the southern limit of species ranges may experience increased mortality rates in the near future. BIOSKETCHThe authors research is focused on functional trait ecology and global change, with special attention to mortality and demography processes. The authors use modelling multidisciplinary approaches to understand complex processes in ecology on a large geographical scale.

ecology