Lipid droplets (LDs; lipid bodies) are intracellular sites of lipid storage and metabolism present in all cell types. Eukaryotic LDs are involved in eicosanoid production during several inflammatory conditions, including infection by protozoan parasites. In parasites, LDs play a role in the acquisition of cholesterol and other neutral lipids from the host. The number of LDs increases during parasite differentiation, and the biogenesis of these organelles use specific signaling pathways involving protein kinases. In addition, LDs are important in cellular protection against lipotoxicity. Recently, these organelles have been implicated in eicosanoid and specialised lipid metabolism. In this article, we revise the main functions of protozoan parasite LDs and discuss future directions in the comprehension of these organelles in the context of pathogen virulence.

The current study was based on data obtained in the Brazilian and French markets, where there are different levels of consolidation of the organic food market: Brazil has 1,136,857 hectares of agricultural land under organic cultivation, which is only 0.4% of the total arable land, and a volume of retail sales of only 4 euros per person per year. France has 1,744,420 hectares of agricultural land under organic cultivation, corresponding to 6.3% of the total arable land, and an annual sales volume of 118 euros per person (Willer & Lernoud, 2019). Another interesting aspect is the difference in financial turnover: in 2015 the turnover in the organic food market was 530 million euros in Brazil (Liu, 2016); while in France the figure was around 5.5 billion euros (Agence BIO, 2016). Ready-for-consumption juices and nectars are in high demand among consumers. In 2017, for example, global consumption was 36.2 billion liters, with around 25% of this consumption in the

BACKGROUND Patients with severe coronavirus disease 2019 (COVID-19) often present with coagulopathies and have high titres of circulating antibodies against viral proteins. OBJECTIVES Herein, we evaluated the association between D-dimer and circulating immunoglobulin levels against viral proteins in patients at different clinical stages of COVID-19. METHODS For this, we performed a cross-sectional study involving patients of the first wave of COVID-19 clinically classified as oligosymptomatic (n = 22), severe (n = 30), cured (n = 27) and non-infected (n = 9). Next, we measured in the plasma samples the total and fraction of immunoglobulins against the nucleoprotein (NP) and the receptor-binding domain (RBD) of the spike proteins by enzyme-linked immunosorbent assay (ELISA) assays. FINDINGS Patients with severe disease had a coagulation disorder with high levels of D-dimer as well as circulating IgG against the NP but not the RBD compared to other groups of patients. In addition, high levels of D-dimer and IgG against the NP and RBD were associated with disease severity among the patients in this study. MAIN CONCLUSIONS Our data suggest that IgG against NP and RBD participates in the worsening of COVID-19. Although the humoral response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is partially understood, and more efforts are needed to clarify gaps in the knowledge of this process.

Leishmania parasites contain lipid droplets (LD, or lipid bodies) and the molecular machinery responsible for synthesizing prostaglandins (PGs) and other bioactive lipids. We studied the effects of polyunsaturated fatty acids (PUFA) on LD biogenesis and eicosanoid production in distinct Leishmania species associated with different clinical forms of leishmaniasis. We also compared structural models of human-like cyclooxygenase-2 (GP63) and prostaglandin F synthase (PGFS) proteins of Leishmania, and we evaluated their enzymatic production in logarithmic and stationary growth phases of procyclic L. amazonensis, L. braziliensis and L. infantum. PUFAs modulate the formation of LDs in L. braziliensis and L. infantum. Leishmania species with equivalent clinical manifestations and tissue tropism had same protein mutations in GP63 and PGFS. No differences in GP63 production were observed among L. amazonensis, L. braziliensis and L. infantum, however increased PGFS production was detected during the parasite differentiation. Stimulation with arachidonic acid resulted in highly elevated production of hydroxyeicosatetraenoic acids compared to prostaglandins quantified by LC-MS/MS. The present findings open new perspectives on the role of eicosanoid metabolism in Leishmania and could contribute to the development of novel antiparasitic drugs.

BACKGROUND The knowledge about eicosanoid metabolism and lipid droplet (LD) formation in the Leishmania is very limited and new approaches are needed to identify which bioactive molecules are produced of them. OBJECTIVES Herein, we compared LDs and eicosanoids biogenesis in distinct Leishmania species which are etiologic agents of different clinical forms of leishmaniasis. METHODS For this, promastigotes of Leishmania amazonensis , L. braziliensis and L. infantum were stimulated with polyunsaturated fatty acids (PUFA) and LD and eicosanoid production was evaluated. We also compared mutations in structural models of human-like cyclooxygenase-2 (GP63) and prostaglandin F synthase (PGFS) proteins, as well as the levels of these enzymes in parasite cell extracts. FINDINGS PUFAs modulate the LD formation in L. braziliensis and L. infantum . Leishmania spp with equivalent tissue tropism had same protein mutations in GP63 and PGFS. No differences in GP63 production were observed among Leishmania spp, however PGFS production increased during the parasite differentiation. Stimulation with arachidonic acid resulted in elevated production of hydroxyeicosatetraenoic acids compared to prostaglandins. MAIN CONCLUSIONS Our data suggest LD formation and eicosanoid production are distinctly modulated by PUFAS dependent of Leishmania species. In addition, eicosanoid-enzyme mutations are more similar between Leishmania species with same host tropism.