Water limitation can negate the effect of higher temperatures on forest carbon sequestration

Abstract

Climate change will bring about a consistent increase in temperatures. Annual precipitation rates are also expected to increase in boreal countries, but the seasonal distribution will be uneven, and several areas in the boreal zone will experience wetter winters and drier summers. This study uses the dynamic forest ecosystem model ForSAFE to estimate the combined effect of changes in temperature and precipitation on forest carbon stocks in Sweden. The model is used to simulate carbon stock changes in 544 productive forest sites from the Swedish National Forest Inventory. Forest carbon stocks under two alternative climate scenarios are compared to stocks under a hypothetical scenario of no climate change (baseline). Results show that lower water availability in the future can cause a significant reduction in tree carbon compared to a baseline scenario, particularly expressed in the southern and eastern parts of Sweden. In contrast, the north-western parts will experience an increase in tree carbon stocks. Results show also that summer precipitation is a better predictor of tree carbon reduction than annual precipitation. Finally, the change in soil carbon stock is less conspicuous than in tree carbon stock, showing no significant change in the north and a relatively small but consistent decline in the south. The study indicates that the prospect of higher water deficit caused by climate change cannot be ignored in future forest management planning.

http://bit.ly/2FNFHDi

Cost-effectiveness of Teriflunomide Compared to Interferon Beta-1b for Relapsing Multiple Sclerosis Patients in China

Abstract

Background and Objective

Teriflunomide is a once-daily oral immunomodulatory agent approved in 80 countries for the treatment of patients with relapsing multiple sclerosis (RMS). The study objective was to estimate the cost effectiveness of teriflunomide (14 mg tablet, daily) versus interferon beta-1b (250 mcg subcutaneous injection, every other day) among RMS patients from the Chinese healthcare system perspective.

Methods

A Markov model with annual cycles and a lifetime horizon was utilized to assess cost-effectiveness of teriflunomide in comparison with interferon beta-1b in RMS patients. Treatment effects, including 3-month confirmed disability worsening and annualized relapse rate, were derived from a network meta-analysis. Cost inputs included costs related to treatment acquisition, administration, monitoring, natural disease management through Expanded Disability Status Scale states, relapse treatment, and adverse event management. These costs were calculated as the product between unit costs from published sources and healthcare resource utilization patterns identified in a survey conducted among 11 neurologists across different areas in China. Health effects were expressed as quality-adjusted life years (QALYs) with costs in local currency (¥) and US dollars (US$), 2018.

Results

Teriflunomide dominated interferon beta-1b and was associated with lower total costs (teriflunomide ¥1,887,144 vs interferon beta-1b ¥2,061,393) and higher QALYs (teriflunomide 9.60 QALYs vs interferon beta-1b 8.88 QALYs). In probabilistic sensitivity analysis, teriflunomide was dominant in 62.2% of model runs.

Conclusion

Teriflunomide is a cost-effective therapy over a lifetime time horizon compared to interferon beta-1b in the treatment of RMS patients in China. Results should be interpreted with caution as head-to-head comparisons are not available.

http://bit.ly/2Ubd3yY

The Asian Lineage of Zika Virus: Transmission and Evolution in Asia and the Americas

Abstract

Since first isolation in 1947 from the Zika forest in Uganda, Zika virus (ZIKV) has been principally known as a benign agent associated with sporadic human infections in a restricted number of African countries. However, during 2015–2016, an Asian lineage of ZIKV caused an unprecedentedly large outbreak in the Americas and sizeable numbers of exported cases across the globe. In this review, we critically appraise the recent advances in molecular epidemiological studies of ZIKV performed to date, and we highlight the pivotal role played by genomic surveillance in elucidating the origins, dissemination and evolution of the Asian lineage of ZIKV in Asia and in the Americas.

http://bit.ly/2MtytF9

Cellular responses to proteostasis perturbations reveal non-optimal feedback in chaperone networks

Abstract

The proteostasis network (PN) comprises a plethora of proteins that are dedicated to aid in protein folding and maintenance; some with overlapping functions. Despite this, there are multiple pathophysiological states associated with depletion of chaperones. This is counter-intuitive, assuming cells have the ability to re-program transcriptional outputs in accordance with its proteostasic limitations. Here, we have used S. cerevisiae to understand how cells respond to different types of proteostasis impairments. We monitored the proteostasis status and transcriptome of single deletions of fourteen different Protein Quality Control (PQC) genes. In most cases, cellular response did not activate proteostasis components or pathways that could either complement the function of the missing PQC gene or restore proteostasis. Over-expression of alternate machineries could restore part of the proteostasis defect in two representative PQC gene deletion strains. We posit that S. cerevisiae inherently lacks the ability to sense and respond optimally to defects in proteostasis caused due to deletion of specific PQC components.

http://bit.ly/2sMTBNo

Link between the unfolded protein response and dysregulation of mitochondrial bioenergetics in Alzheimer’s disease

Abstract

Alzheimer's disease (AD) is a progressive neurodegenerative disorder affecting more than 47.5 million people worldwide. Metabolic impairments are common hallmarks of AD, and amyloid-β (Aβ) peptide and hyperphosphorylated tau protein—the two foremost histopathological signs of AD—have been implicated in mitochondrial dysfunction. Many neurodegenerative disorders, including AD, show excessive amounts of mis-/unfolded proteins leading to an activation of the unfolded protein response (UPR). In the present study, we aimed to characterize the link between ER stress and bioenergetics defects under normal condition (human SH-SY5Y neuroblastoma cells: control cells) or under pathological AD condition [SH-SY5Y cells overexpressing either the human amyloid precursor protein (APP) or mutant tau (P301L)]. More specifically, we measured UPR gene expression, cell viability, and bioenergetics parameters, such as ATP production and mitochondrial membrane potential (MMP) in basal condition and after an induced ER stress by thapsigargin. We detected highly activated UPR and dysregulated bioenergetics in basal condition in both AD cellular models. Strikingly, acute-induced ER stress increased the activity of the UPR in both AD cellular models, leading to up-regulation of apoptotic pathways, and further dysregulated mitochondrial function.

http://bit.ly/2MteDcU

The HMG box transcription factor HBP1: a cell cycle inhibitor at the crossroads of cancer signaling pathways

Abstract

HMG box protein 1 (HBP1) is a transcription factor and a potent cell cycle inhibitor in normal and cancer cells. HBP1 activates or represses the expression of different cell cycle genes (such as CDKN2A, CDKN1A, and CCND1) through direct DNA binding, cofactor recruitment, chromatin remodeling, or neutralization of other transcription factors. Among these are LEF1, TCF4, and MYC in the WNT/beta-catenin pathway. HBP1 also contributes to oncogenic RAS-induced senescence and terminal cell differentiation. Collectively, these activities suggest a tumor suppressor function. However, HBP1 is not listed among frequently mutated cancer driver genes. Nevertheless, HBP1 expression is lower in several tumor types relative to matched normal tissues. Several micro-RNAs, such as miR-155, miR-17-92, and miR-29a, dampen HBP1 expression in cancer cells of various origins. The phosphatidylinositol-3 kinase (PI3K)/AKT pathway also inhibits HBP1 transcription by preventing FOXO binding to the HBP1 promoter. In addition, AKT directly phosphorylates HBP1, thereby inhibiting its transcriptional activity. Taken together, these findings place HBP1 at the center of a network of micro-RNAs and oncoproteins that control cell proliferation. In this review, we discuss our current understanding of HBP1 function in human physiology and diseases.

http://bit.ly/2sLdZP5

The functional roles of exosomal long non-coding RNAs in cancer

Abstract

Exosomes are extracellular membranous vesicles that are secreted by various cell types. Exosomes have become indispensable facilitators in the exchange of information between cells. More importantly, exosomes perform a crucial role in a variety of diseases including cancers. Long non-coding RNAs (lncRNAs) are over 200 nucleotides long transcripts that exhibit no or limited protein-coding potentials. LncRNAs are an emerging group of regulatory RNAs and can be selectively packaged into exosomes. Exosomal lncRNAs play a central role in carcinogenesis and cancer progression by modulating tumor growth, metastasis, angiogenesis and chemoresistance. Moreover, exosomal lncRNAs function as messengers in cell-to-cell communication, and thus remodel the tumor microenvironment. Their function relevance in cancer biology hints at the possibility of employing exosomal lncRNAs as promising, non-invasive biomarkers for further cancer therapy. In this review, we provide an overview of current research on the functional roles of exosomal lncRNAs in cancer and discuss their potential clinical applications as diagnostic biomarkers and therapeutic targets for cancers.

http://bit.ly/2MxMKAp