Lipid droplets in leukocytes: Organelles linked to inflammatory responses

Melo, Rossana C. N.; Weller, Peter F.

doi:10.1016/j.yexcr.2015.10.028

Cited by 66 publications

(63 citation statements)

References 38 publications

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“…This non‐invasive and non‐destructive technique found a great use in the analysis of different blood cells, also on the intra‐cellular level. Certainly, its application may contribute to a better understanding of processes associated with the immune response and inflammation involving eosinophils, as their LBs dynamically respond through activation of mediators like eicosanoids and the cytokine, TNF (Melo & Weller, ). They are associated with the incompletely unnderstood aetiology of eosinophilia‐based diseases, such as aspirin‐related asthma, acute myeloid leukaemia, Crohn's disease, cancer, immunodeficiency and others (Kovalszki & Weller, ).…”

Section: Discussionmentioning

confidence: 99%

“…An increased number and size of LBs correlate with the occurrence of inflammation, being the response to allergic factors, parasitic and bacterial infections. The images recorded by transmission electron microscopy as well as bright field and fluorescent microscopy provided the basis for this conclusion (Blanchard & Roethenberg, ; Melo et al , ; Melo & Weller, ).…”

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confidence: 96%

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Raman imaging highlights biochemical heterogeneity of human eosinophils versus human eosinophilic leukaemia cell line

et al. 2019

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Summary Eosinophils are acidophilic granulocytes that develop in the bone marrow. Although their population contributes only to approximately 1–6% of all leucocytes present in the human blood, they possess a wide range of specific functions. They play a key role in inflammation‐regulating processes, when their numbers can increased to above 5 × 109/l of peripheral blood. Their characteristic feature is the presence of granules containing eosinophil peroxidase (EPO), the release of which can trigger a cascade of events promoting oxidative stress, apoptosis or necrosis, leading finally to cell death. Raman spectroscopy is a powerful technique to detect EPO, which comprises a chromophore protoporphyrin IX. Another cell structure associated with inflammation processes are lipid bodies (lipid‐rich organelles), also well recognized and imaged using high resolution confocal Raman spectroscopy. In this work, eosinophils isolated from the blood of a human donor were analysed versus their model, EoL‐1 human eosinophilic leukaemia cell line, by Raman spectroscopic imaging. We showed that EPO was present only in primary cells and not found in the cell line. Eosinophils were activated using phorbol 12‐myristate 13‐acetate, which resulted in lipid bodies formation. An effect of cells stimulation was studied and compared for eosinophils and EoL‐1.

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Section: Discussionmentioning

confidence: 99%

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confidence: 96%

Raman imaging highlights biochemical heterogeneity of human eosinophils versus human eosinophilic leukaemia cell line

et al. 2019

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“…AA is an essential fatty acid present in the phospholipids of cell membranes [54] and it is also stored within LDs mainly in cells from the immune system (reviewed in [23, 55]). It is a precursor of a large family of pro-inflammatory eicosanoids, including the prostaglandins and leukotrienes through enzymes such as cyclooxygenase and lipoxygenase [54].…”

Section: Discussionmentioning

confidence: 99%

Natural Schistosoma mansoni Infection in the Wild Reservoir Nectomys squamipes Leads to Excessive Lipid Droplet Accumulation in Hepatocytes in the Absence of Liver Functional Impairment

et al. 2016

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Schistosomiasis is a neglected tropical disease of a significant public health impact. The water rat Nectomys squamipes is one of the most important non-human hosts in the schistosomiasis mansoni transmission in Brazil, being considered a wild reservoir. Cellular mechanisms that contribute to the physiological adaptation of this rodent to the Schistosoma mansoni parasite are poorly understood. Here we identified, for the first time, that a hepatic steatosis, a condition characterized by excessive lipid accumulation with formation of lipid droplets (LDs) within hepatocytes, occurs in response to the natural S. mansoni infection of N. squamipes, captured in an endemic region. Significant increases of LD area in the hepatic tissue and LD numbers/hepatocyte, detected by quantitative histopathological and ultrastructural analyses, were paralleled by increased serum profile (total cholesterol and triglycerides) in infected compared to uninfected animals. Raman spectroscopy showed high content of polyunsaturated fatty acids (PUFAs) in the liver of both groups. MALDI-TOFF mass spectroscopy revealed an amplified pool of omega-6 PUFA arachidonic acid in the liver of infected animals. Assessment of liver functional activity by the levels of hepatic transaminases (ALT and AST) did not detect any alteration during the natural infection. In summary, this work demonstrates that the natural infection of the wild reservoir N. squamipes with S. mansoni elicits hepatic steatosis in the absence of liver functional harm and that accumulation of lipids, markedly PUFAs, coexists with low occurrence of inflammatory granulomatous processes, suggesting that lipid stores may be acting as a protective mechanism for dealing with the infection.

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“…LDs are also known to be involved in lipid metabolism associated with pathogen infection (Herker and Ott, 2012;Murphy, 2012), and biochemical studies have shown a significant increase in TAG and neutral lipids in plants subjected to heat, cold, drought, and salt stress (Mueller et al, 2015;Tarazona et al, 2015). LDs are also well known to be important in inflammatory responses in mammals (Melo and Weller, 2016). Taken together, it is likely that LD proliferation is a common cellular response during stress.…”

Section: A Role For Ldaps During the Plant Stress Responsementioning

confidence: 99%

Lipid Droplet-Associated Proteins (LDAPs) Are Required for the Dynamic Regulation of Neutral Lipid Compartmentation in Plant Cells

et al. 2016

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Eukaryotic cells compartmentalize neutral lipids into organelles called lipid droplets (LDs), and while much is known about the role of LDs in storing triacylglycerols in seeds, their biogenesis and function in nonseed tissues are poorly understood. Recently, we identified a class of plant-specific, lipid droplet-associated proteins (LDAPs) that are abundant components of LDs in nonseed cell types. Here, we characterized the three LDAPs in Arabidopsis (Arabidopsis thaliana) to gain insight to their targeting, assembly, and influence on LD function and dynamics. While all three LDAPs targeted specifically to the LD surface, truncation analysis of LDAP3 revealed that essentially the entire protein was required for LD localization. The association of LDAP3 with LDs was detergent sensitive, but the protein bound with similar affinity to synthetic liposomes of various phospholipid compositions, suggesting that other factors contributed to targeting specificity. Investigation of LD dynamics in leaves revealed that LD abundance was modulated during the diurnal cycle, and characterization of LDAP misexpression mutants indicated that all three LDAPs were important for this process. LD abundance was increased significantly during abiotic stress, and characterization of mutant lines revealed that LDAP1 and LDAP3 were required for the proper induction of LDs during heat and cold temperature stress, respectively. Furthermore, LDAP1 was required for proper neutral lipid compartmentalization and triacylglycerol degradation during postgerminative growth. Taken together, these studies reveal that LDAPs are required for the maintenance and regulation of LDs in plant cells and perform nonredundant functions in various physiological contexts, including stress response and postgerminative growth.

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Lipid droplets in leukocytes: Organelles linked to inflammatory responses

Cited by 66 publications

References 38 publications

Raman imaging highlights biochemical heterogeneity of human eosinophils versus human eosinophilic leukaemia cell line

Raman imaging highlights biochemical heterogeneity of human eosinophils versus human eosinophilic leukaemia cell line

Natural Schistosoma mansoni Infection in the Wild Reservoir Nectomys squamipes Leads to Excessive Lipid Droplet Accumulation in Hepatocytes in the Absence of Liver Functional Impairment

Lipid Droplet-Associated Proteins (LDAPs) Are Required for the Dynamic Regulation of Neutral Lipid Compartmentation in Plant Cells

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