Protective Response Mechanisms to Heat Stress in Interaction with High [CO2] Conditions in Coffea spp.

This work was supported by national funds from Fundacao para a Ciencia e a Tecnologia through the projects PTDC/AGRPRO/3386/2012, the research units UID/AGR/04129/2013 (LEAF) and UID/GEO/04035/2013 (GeoBioTcc), as well through the grant SFRH/BPD/47563/2008 (AT) co-financed through the POPH program subsidized by the European Social Fund. Brazilian funding from CAPES (grams PDSE: 000427/2014-04, W.P. Rodrigues; 0343/2014-05, MM; 12226/12-2, LM), CNPq and Fapemig (fellowships to FDM, FP, and EC) are also greatly acknowledged.Modeling studies have predicted that coffee crop will be endangered by future global warming, but recent reports highlighted that high [CO2] can mitigate heat impacts on coffee. This work aimed at identifying heat protective mechanisms promoted by CO2 in Coffea arabica (cv. Icatu and IPR108) and Coffea canephora cv. Conilon CL153. Plants were grown at 25/20 degrees C (day/night), under 380 or 700 mu L CO2 L-1, and then gradually submitted to 31/25, 37/30, and 42/34 degrees C. Relevant heat tolerance up to 37/30 degrees C for both [CO2] and all coffee genotypes was observed, likely supported by the maintenance or increase of the pools of several protective molecules (neoxanthin, lutein, carotenes, ohtocopherol, HSP70, raffinose), activities of antioxidant enzymes, such as superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), catalase (CAT), and the upregulated expression of some genes (ELIP, Chaperonin 20). However, at 42/34 degrees C a tolerance threshold was reached, mostly in the 380 -plants and Icatu. Adjustments in raffinose, lutein, beta-carotene, alpha-tocopherol and HSP70 pools, and the upregulated expression of genes related to protective (FLIPS, HSP70, Chape 20, and 60) and antioxidant (CAT, CuSOD2, APX Cyt, APX ChI) proteins were largely driven by temperature. However, enhanced [CO2] maintained higher activities of GR (Icatu) and CAT (Icatu and IPR108), kept (or even increased) the Cu,Zn-SOD, APX, and CAT activities, and promoted a greater upregulation of those enzyme genes, as well as those related to HSP70, ELIPs, Chaperonins in CL153, and Icatu. These changes likely favored the maintenance of reactive oxygen species (ROS) at controlled levels and contributed to mitigate of photosystem II photoinhibition at the highest temperature. Overall, our results highlighted the important role of enhanced [CO2] on the coffee crop acclimation and sustainability under predicted future global warming scenarios.publishersversionpublishe

Lipid profile adjustments may contribute to warming acclimation and to heat impact mitigation by elevated [CO2] in Coffea spp

This work was supported by European Union, Program Horizon 2020, call H2020-SFS-2016-2, action RIA, and Portuguese national funds from Fundacao para a Ciencia e a Tecnologia (project PTDC/ASP-AGR/31257/2017; Funding from CNPq (fellowships to E. Campostrini, F.L. Partelli, and F.M. DaMatta) is also acknowledged.An unexpected heat resilience, and the mitigation of heat impacts by elevated [CO2] were recently reported in Coffea spp. Plants must maintain membrane fluidity and integrity to cope with temperature changes, which requires an adequate lipid dynamics. This work provides the lipid profile (galactolipids, GL; phospholipids, PL; sulfolipids, SL) of chloroplast membranes, and the expression of a set of genes related to lipid metabolism in Coffea arabica L. (cv. Icatu and IPR108) and C. canephora cv. Conilon CL153, under elevated [CO2] (380 or 700 μL L−1), heat (25/20, 31/25, 37/30 and 42/34 °C, day/night) and their interaction. Major membrane lipids alterations, different among genotypes, included: A) responsiveness of total fatty acids (TFAs) synthesis to [CO2] (except IPR108) and heat (except CL153); stronger remodeling (unsaturation degree) in the 700-plants from 37/30 °C to 42/34 °C, coordinated at transcriptional level with the down-regulation of fatty acid desaturase FAD3 gene (C. arabica) and up-regulation of lipoxygenase genes LOX5A (CL153 and Icatu) and LOX5B (Icatu) at the highest temperature; B) quantitative and qualitative modifications in GL (monogalactosyldiacylglycerol, MGDG; digalactosyldiacylglycerol, DGDG), PL (phosphatidylcholine, PC; phosphatidylglycerol, PG), and SL (sulfoquinovosyldiacylglycerol, SQDG) classes, prompted by heat, elevated [CO2], and, especially, the interaction, in CL153 and Icatu. Overall membrane enrichment with MGDG and DGDG as a result of heat and [CO2] interaction in these genotypes, but at the highest temperature only in Icatu the high [CO2] maintained greater contents and unsaturation values of these GLs than in the 380-plants. C) Among PL classes, PG seems to play an active role in heat acclimation of C. arabica genotypes, increasing in 700-plants at 42/34 °C. Globally, Icatu often showed changes closer to those of heat tolerant cv. CL153 than to cv. IPR108. Overall, lipid profile adjustments in chloroplast membranes, from TFAs bulk until FA unsaturation within each class, are expected to contribute to long-term acclimation to climate changes in coffee plant.publishersversionpublishe

Hysteretic Behavior of Proprotein Convertase 1/3 (PC1/3)

The proprotein convertases (PCs) are calcium-dependent proteases responsible for processing precursor proteins into their active forms in eukariotes. The PC1/3 is a pivotal enzyme of this family that participates in the proteolytic maturation of prohormones and neuropeptides inside the regulated secretory pathway. In this paper we demonstrate that mouse proprotein convertase 1/3 (mPC1/3) has a lag phase of activation by substrates that can be interpreted as a hysteretic behavior of the enzyme for their hydrolysis. This is an unprecedented observation in peptidases, but is frequent in regulatory enzymes with physiological relevance. The lag phase of mPC1/3 is dependent on substrate, calcium concentration and pH. This hysteretic behavior may have implications in the physiological processes in which PC1/3 participates and could be considered an additional control step in the peptide hormone maturation processes as for instance in the transformation of proinsulin to insulin

Effects of APOE, APOB and LDLR variants on serum lipids and lack of association with xanthelasma in individuals from Southeastern Brazil

Xanthelasma might be a clinical manifestation of dyslipidemia, a recognized risk factor for coronary artery disease. We investigated the association of apolipoprotein E (APOE HhaI), apolipoprotein B (APOB XbaI and Ins/Del) and LDL receptor (LDLR AvaII and HincII) gene polymorphisms with lipid profiles in 100 Brazilians with xanthelasma and 100 controls. Allele frequencies were similar in both groups. APOE, APOB and LDLR genotypes were not correlated with differences in the serum lipid profile. In individuals with xanthelasma, the APOB D allele was associated with less chance of having increased LDL-cholesterol (O.R. = 0.16, CI95% = 0.03-0.94, p = 0.042). In the control group, the APOB X+ allele was associated with less chance of having both increased total cholesterol (O.R. = 0.16, CI95% = 0.03-0.78, p = 0.023) and increased LDL-cholesterol (O.R. = 0.10, CI95% = 0.02-0.60, p = 0.012). Moreover, there was a significantly higher frequency of control individuals (68%) with elevated serum triglyceride levels, compared to patients (48%, p = 0.008). On the other hand, triglyceride levels in controls also seemed to be influenced by all other gene polymorphisms studied, an effect that might be enhanced by environmental factors

Low prevalence of renal, cardiac, pulmonary, and neurological extra-articular clinical manifestations in spondyloarthritis: analysis of the Brazilian Registry of Spondyloarthritis

OBJECTIVE: To describe the extra-articular manifestations (cardiac, renal, pulmonary, and neurological), usually not related to spondyloarthritis (SpA), in a large cohort of Brazilian patients. MATERIALS AND METHODS: This retrospective study analyzed 1,472 patients diagnosed with SpA and cared for at 29 health care centers distributed in the five major geographic regions in the country, participating in the Brazilian Registry of Spondyloarthritis (BRS). All patients were assessed for the prevalence of major extra-articular manifestations (cardiac, renal, pulmonary, and neurological), classified according to the diagnosis [ankylosing spondylitis (AS), psoriatic arthritis (PsA), reactive arthritis (ReA), arthritis associated with inflammatory bowel disease (IBD), undifferentiated spondyloarthritis (uSpA), and juvenile SpA], and according to the clinical presentation (axial, peripheral, mixed, and enthesitis). RESULTS: Of the patients with SpA assessed, 963 had AS, 271 PsA, 49 ReA, 48 arthritis associated with IBD, 98 uSpA, and 43 juvenile SpA. Cardiac involvement was reported in 44 patients (3.0%), pulmonary involvement in 19 (1.3%), renal involvement in 17 (1.2%), and neurological involvement in 13 patients (0.9%). Most patients with visceral involvement had AS or PsA, and the mixed (axial + peripheral) and/or predominantly axial clinical form. CONCLUSION: Cardiac, renal, pulmonary, and neurological extra-articular manifestations are quite infrequent in SpA, ranging from 0.9% to 3% in this large Brazilian cohort, and affected predominantly patients with AS and PsA.OBJETIVO: Descrever as manifestações extra-articulares (cardíacas, renais, pulmonares e neurológicas) geralmente não relacionadas às espondiloartrites (EpA) em uma grande coorte de pacientes brasileiros. MÉTODOS: Este estudo retrospectivo analisou 1.472 pacientes com o diagnóstico de EpA atendidos em 29 centros distribuídos pelas cinco principais regiões geográficas do Brasil, integrantes do Registro Brasileiro de Espondiloartrites. Todos os pacientes foram avaliados para a prevalência das principais manifestações extra-articulares (cardíacas, renais, pulmonares e neurológicas), divididas por diagnóstico [espondilite anquilosante (EA), artrite psoriásica (AP), artrite reativa (ARe), artrite associada a doença inflamatória intestinal (DII), EpA indiferenciada (EI) e EpA juvenil] e por forma clínica (axial, periférica, mista e entesítica). RESULTADOS: Dentre os pacientes avaliados com EpA, 963 apresentavam EA, 271 AP, 49 ARe, 48 artrite associada a DII, 98 EI e 43 EpA juvenil. Acometimento cardíaco foi observado em 44 pacientes (3,0%), seguido por acometimento pulmonar em 19 (1,3%), renal em 17 (1,2%) e neurológico em 13 pacientes (0,9%). A maioria dos casos de acometimento visceral ocorreu nos pacientes com EA ou AP e naqueles com forma clínica mista (axial e periférica) e/ou predominantemente axial. CONCLUSÃO: As manifestações extra-articulares cardíacas, renais, pulmonares e neurológicas são muito pouco frequentes nas EpA, variando de 0,9%-3% nesta grande coorte brasileira, estando mais associadas a EA e AP.37938