Cerebrospinal fluid chitinases as biomarkers for Amyotrophic Lateral Sclerosis

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Amyotrophic lateral sclerosis (ALS) is a neurodegenerative neuromuscular disease that affects motor neurons controlling voluntary muscles. Survival is usually 2-5 years after onset, and death occurs due to respiratory failure. The identification of biomarkers would be very useful to help in disease diagnosis and for patient stratification based on, e.g., progression rate, with implications in therapeutic trials. Neurofilaments constitute already-promising markers for ALS and, recently, chitinases have emerged as novel marker targets for the disease. Here, we investigated cerebrospinal fluid (CSF) chitinases as potential markers for ALS. Chitotriosidase (CHIT1), chitinase-3-like protein 1 (CHI3L1), chitinase-3-like protein 2 (CHI3L2) and the benchmark marker phosphoneurofilament heavy chain (pNFH) were quantified by an enzyme-linked immunosorbent assay (ELISA) from the CSF of 34 ALS patients and 24 control patients with other neurological diseases. CSF was also analyzed by UHPLC-mass spectrometry. All three chitinases, as well as pNFH, were found to correlate with disease progression rate. Furthermore, CHIT1 was elevated in ALS patients with high diagnostic performance, as was pNFH. On the other hand, CHIT1 correlated with forced vital capacity (FVC). The three chitinases correlated with pNFH, indicating a relation between degeneration and neuroinflammation. In conclusion, our results supported the value of CHIT1 as a diagnostic and progression rate biomarker, and its potential as respiratory function marker. The results opened novel perspectives to explore chitinases as biomarkers and their functional relevance in ALS.We acknowledge iNOVA4Health – UIDB/04462/2020 and UIDP/04462/2020, a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior, through national funds.info:eu-repo/semantics/publishedVersio

Campo rupestre recém-queimado na Chapada Diamantina, Bahia, Brasil: plantas de rebrota e sementes, com espécies endêmicas na rocha Recently burnt 'campo rupestre' in the Chapada Diamantina, Bahia, Brazil: resprouters and seeders, with endemic rock species

O fogo é um distúrbio recorrente em muitas áreas da Chapada Diamantina, geralmente originado por ação antrópica e que ocasiona rápidas mudanças nas comunidades. Este trabalho objetiva conhecer a composição e estrutura da vegetação de uma área de campo rupestre recém-queimada no Parque Nacional da Chapada Diamantina, Bahia, Brasil, situada entre 700 e 800 m acima do nível do mar, visando discussão das estratégias de regeneração das espécies mais conspícuas e das similaridades florísticas entre áreas com e sem distúrbio recente de fogo. Foi realizado um censo das espécies de plantas vasculares ocorrentes em 16 parcelas de 10x10 m, sendo as coberturas estimadas em cinco subparcelas de 2x2 m de cada parcela. Foram encontradas 85 espécies de 34 famílias, sendo 11 de monocotiledôneas, 22 de eudicotiledôneas e uma de monilófita. A espécie mais abundante foi Panicum trinii Kunth (Poaceae) e a mais frequente Periandra mediterranea (Vell.) Taub. (Fabaceae). O índice de Shannon foi 3,4. A área estudada agrupou-se com a área de afloramento rochoso em altitude menos elevada (38% de similaridade). É possível que o fogo seja mais frequente nessas áreas menos isoladas, em relação às dos topos de morros. As espécies dominantes se restabeleceram principalmente a partir de gemas de sistemas subterrâneos e aéreos. Uma das espécies mais frequentes, Dactylaena microphylla Eichler, estabeceu-se de sementes. Espécies endêmicas sensíveis à ação do fogo sobrevivem em ilhas de vegetação nos afloramentos rochosos.<br>Fire is a recurrent disturbance in many areas of Chapada Diamantina, generally set by human activity that drives rapid changes in communities. This study aims to investigate the composition and structure of 'campo rupestre' vegetation in a recently burned area, between 700 and 800 m above sea level, at Chapada Diamantina National Park, Bahia, Brazil, and to discuss the strategies of regeneration for the most conspicuous species and floristic similarities among sites with and without recent fire disturbance. A species census of all vascular plants in 16 plots (10x10 m) was performed, and species cover was estimated in five subplots (2x2 m). 85 species were found, distributed among 34 families, including 11 monocotyledons, 22 eudicotyledons and one monilophyte. The most abundant specie was Panicum trinii Kunth (Poaceae) and the most frequent was Periandra mediterranea (Vell.) Taub (Fabaceae). The Shannon index was 3.4. The study area grouped with a rocky area at lower altitudes (38% similarity). Probably, fire is more frequent in these areas than on hill summits. The main dominant species resprouted from underground buds and from aerial organs. One of the most frequent species, Dactylaena microphylla Eichler, was established from seed. Fire-sensitive endemic species survive on vegetation islands on rocky outcrops

Human impacts and aridity differentially alter soil N availability in drylands worldwide

[Aims]: Climate and human impacts are changing the nitrogen (N) inputs and losses in terrestrial ecosystems. However, it is largely unknown how these two major drivers of global change will simultaneously influence the N cycle in drylands, the largest terrestrial biome on the planet. We conducted a global observational study to evaluate how aridity and human impacts, together with biotic and abiotic factors, affect key soil variables of the N cycle.[Location]: Two hundred and twenty-four dryland sites from all continents except Antarctica widely differing in their environmental conditions and human influence.[Methods]: Using a standardized field survey, we measured aridity, human impacts (i.e. proxies of land uses and air pollution), key biophysical variables (i.e. soil pH and texture and total plant cover) and six important variables related to N cycling in soils: total N, organic N, ammonium, nitrate, dissolved organic:inorganic N and N mineralization rates. We used structural equation modelling to assess the direct and indirect effects of aridity, human impacts and key biophysical variables on the N cycle.[Results]: Human impacts increased the concentration of total N, while aridity reduced it. The effects of aridity and human impacts on the N cycle were spatially disconnected, which may favour scarcity of N in the most arid areas and promote its accumulation in the least arid areas.[Main conclusions]: We found that increasing aridity and anthropogenic pressure are spatially disconnected in drylands. This implies that while places with low aridity and high human impact accumulate N, most arid sites with the lowest human impacts lose N. Our analyses also provide evidence that both increasing aridity and human impacts may enhance the relative dominance of inorganic N in dryland soils, having a negative impact on key functions and services provided by these ecosystems.This research is supported by the European Research Council (ERC) under the European Community's Seventh Framework Programme (FP7/2007‐2013)/ERC grant agreement no. 242658 (BIOCOM), and by the Ministry of Science and Innovation of the Spanish Government, grant no. CGL2010‐21381. CYTED funded networking activities (EPES, Acción 407AC0323). S.G. was funded by CONICYT/FONDAP/15110009.Peer Reviewe

Human impacts and aridity differentially alter soil N availability in drylands worldwide

Aims Climate and human impacts are changing the nitrogen (N) inputs and losses in terrestrial ecosystems. However, it is largely unknown how these two major drivers of global change will simultaneously influence the N cycle in drylands, the largest terrestrial biome on the planet. We conducted a global observational study to evaluate how aridity and human impacts, together with biotic and abiotic factors, affect key soil variables of the N cycle. Location Two hundred and twenty-four dryland sites from all continents except Antarctica widely differing in their environmental conditions and human influence. Methods Using a standardized field survey, we measured aridity, human impacts (i.e. proxies of land uses and air pollution), key biophysical variables (i.e. soil pH and texture and total plant cover) and six important variables related to N cycling in soils: total N, organic N, ammonium, nitrate, dissolved organic:inorganic N and N mineralization rates. We used structural equation modelling to assess the direct and indirect effects of aridity, human impacts and key biophysical variables on the N cycle. Results Human impacts increased the concentration of total N, while aridity reduced it. The effects of aridity and human impacts on the N cycle were spatially disconnected, which may favour scarcity of N in the most arid areas and promote its accumulation in the least arid areas. Main conclusions We found that increasing aridity and anthropogenic pressure are spatially disconnected in drylands. This implies that while places with low aridity and high human impact accumulate N, most arid sites with the lowest human impacts lose N. Our analyses also provide evidence that both increasing aridity and human impacts may enhance the relative dominance of inorganic N in dryland soils, having a negative impact on key functions and services provided by these ecosystems

Decoupling of soil nutrient cycles as a function of aridity in global drylands

The biogeochemical cycles of carbon (C), nitrogen (N) and phosphorus (P) are interlinked by primary production, respiration and decomposition in terrestrial ecosystems. It has been suggested that the C, N and P cycles could become uncoupled under rapid climate change because of the different degrees of control exerted on the supply of these elements by biological and geochemical processes. Climatic controls on biogeochemical cycles are particularly relevant in arid, semi-arid and dry sub-humid ecosystems (drylands) because their biological activity is mainly driven by water availability. The increase in aridity predicted for the twenty-first century in many drylands worldwide may therefore threaten the balance between these cycles, differentially affecting the availability of essential nutrients. Here we evaluate how aridity affects the balance between C, N and P in soils collected from 224 dryland sites from all continents except Antarctica. We find a negative effect of aridity on the concentration of soil organic C and total N, but a positive effect on the concentration of inorganic P. Aridity is negatively related to plant cover, which may favour the dominance of physical processes such as rock weathering, a major source of P to ecosystems, over biological processes that provide more C and N, such as litter decomposition. Our findings suggest that any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P. These changes would uncouple the C, N and P cycles in drylands and could negatively affect the provision of key services provided by these ecosystems

Grazing and ecosystem service delivery in global drylands

Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that interactions between grazing pressure, climate, soil, and biodiversity are critical to explain the delivery of fundamental ecosystem services across drylands worldwide. Increasing grazing pressure reduced ecosystem service delivery in warmer and species-poor drylands, whereas positive effects of grazing were observed in colder and species-rich areas. Considering interactions between grazing and local abiotic and biotic factors is key for understanding the fate of dryland ecosystems under climate change and increasing human pressure

Data and R code from "Grazing and ecosystem service delivery in global drylands"

There are two zip files with the data and R scripts used in the article "Grazing and ecosystem service delivery in global drylands". The file "Main_Data_code.zip" contains the data and R code used in the main analyses of the paper. These data also include the location and major environmental characteristics of the plots surveyed. The file "Livestock_data_code.zip" contains the data and R code used in the characterization and validation of grazing pressure levels (see Methods). Readme and metadata files including a description of the files, variables and units are provided. All the methodological details can be found in the article. Additional authors from the BIODESERT consortium not included in the author list (we reached the maximum number of authors allowed by figshare) include:  Víctor Rolo, Juan G. Rubalcaba, Jan C. Ruppert, Ayman Salah, Max A. Schuchardt, Sedona Spann, Ilan Stavi, Colton R. A.Stephens, Anthony M. Swemmer, Alberto L. Teixido, Andrew D. Thomas, Heather L. Throop, Katja Tielbörger, Samantha Travers, James Val, Orsolya Valkó, Liesbeth van den Brink, Sergio Velasco Ayuso, Frederike Velbert, Wanyoike Wamiti, Deli Wang, Lixin Wang, Glenda M. Wardle, Laura Yahdjian, Eli Zaady, Yuanming Zhang and Xiaobing Zhou </p