Chronic lymphocytic leukemia (CLL) is the most prevalent lymphoid malignancy in many geographical regions of the world. Pseurotin D, a secondary metabolite of fungi, represents a group of bioactive natural products with a newly ascribed range of interesting biological activities. The purpose of this study was to bring new insights into the mechanism behind the effects of pseurotin D on MEC-1 cells as a representative CLL cell line, with a particular focus on selected signaling pathways important in the proliferation of cells and targeting mitochondrial metabolism. Our results showed that pseurotin D was able to significantly inhibit the proliferation of MEC-1 cells and arrested them in the G2/M cell cycle phase. In addition, pseurotin D was able to induce apoptosis. We found that all of these effects were associated with a change in mitochondrial membrane potential and the production of mitochondrial reactive oxygen species (ROS). We showed for the first time that pseurotin D suppresses MEC-1 cell proliferation and induces apoptotic cell death via induction of the collapse of the mitochondria respiratory chain and the ROS-related caspase pathway. Our results show the pseurotins family as promising compounds which could serve as a basis for the development of new compounds in the treatment of lymphoma.

• Klíčová slova
• apoptosis, lymphoma, mitochondrial activity, proliferation, pseurotin D, reactive oxygen species,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Pseurotins, a family of secondary metabolites of different fungi characterized by an unusual spirocyclic furanone-lactam core, are suggested to have different biological activities including the modulation of immune response. PURPOSE: Complex characterization of the effects of pseurotin D on human lymphocyte activation in order to understand the potential of pseurotin to modulate immune response in humans. METHODS: CD4+ and CD8+ T cells and CD19+ B cells isolated from human blood were activated by various activators simultaneously with pseurotin D treatment. The effects of pseurotin were tested on the basis of changes in cell viability, apoptosis, activation of signal transducers and activators of transcription (STAT) signaling pathways, production of tumor necrosis factor (TNF)-α by T cells, expression of activation markers CD69 and CD25 on T cells and Human Leukocyte Antigen-DR isotype (HLA-DR) on B cells, and the differentiation markers CD20, CD27, CD38, and immunoglobulin (Ig) D on B cells. RESULTS: Pseurotin D significantly inhibited the activation of both CD4+ and CD8+ human T cells complemented by the inhibition of TNF-α production without significant acute toxic effects. The Pseurotin D-mediated inhibition of T-cell activation was accompanied by the induction of the apoptosis of T cells. This corresponded with the inhibited phosphorylation of STAT3 and STAT5. In human B cells, pseurotin D did not significantly inhibit their activation; however, it affected their differentiation. CONCLUSIONS: Our results advance the current mechanistic understanding of the pseurotin-induced inhibition of lymphocytes and suggest pseurotins as new attractive chemotypes for future research in the context of immune-modulatory drugs.

• Klíčová slova
• STAT3, STAT5, lymphocyte, proliferation, pseurotin,
• MeSH
• aktivace lymfocytů účinky léků   MeSH
• antigeny CD19 metabolismus   MeSH
• apoptóza účinky léků   MeSH
• B-lymfocyty účinky léků   imunologie   MeSH
• buněčná diferenciace účinky léků   MeSH
• CD4-pozitivní T-lymfocyty účinky léků   imunologie   MeSH
• CD8-pozitivní T-lymfocyty účinky léků   imunologie   MeSH
• dospělí MeSH
• imunologické faktory farmakologie   MeSH
• kultivované buňky MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• pyrrolidinony farmakologie   MeSH
• signální transdukce účinky léků   MeSH
• TNF-alfa metabolismus   MeSH
• zdraví dobrovolníci pro lékařské studie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny CD19 MeSH
• CD19 molecule, human MeSH Prohlížeč
• imunologické faktory MeSH
• pseurotin d MeSH Prohlížeč
• pyrrolidinony MeSH
• TNF protein, human MeSH Prohlížeč
• TNF-alfa MeSH

In this study, we focused on comparing the effects of serotonin and its metabolites on the functions of RAW264.7 cells (emphasis on oxidative burst and production of nitric oxide and cytokines), thereby expanding the scope of existing knowledge with advent of novel findings in this field. Changes in production of reactive oxygen species (ROS) by RAW264.7 cells after treatment with serotonin, N-acetylserotonin and melatonin were determined using the chemiluminescence (CL) assay. To exclude the direct scavenging effects of the studied compounds on the CL response, the antioxidant properties of all respective compounds were measured using TRAP and amperometrical method. Nitric oxide (NO) production was measured by Griess reagent and inducible NO synthase (iNOS) expression by Western blot. Cytokine production was assessed using the Mouse Cytokine Panel A Array kit and ELISA. We showed that all tested compounds were able to reduce oxidative stress, as well as inhibit production of inflammatory cytokines by macrophages. Of the tested compounds, serotonin and N-acetylserotonin were markedly better antioxidants than melatonin. In comparison, other effects of tested compounds were very similar. It can be concluded that antioxidant capacity of tested compounds is a major advantage in the early stages of inflammation. Since plasma concentrations of N-acetylserotonin and melatonin are lower than serotonin, it can be deduced that serotonin plays a key role in modulation of inflammation and the regulatory functions of immune cells, while also protecting cells against oxidative stress.

• Klíčová slova
• Cytokines, Melatonin, N-acetylserotonin, Nitric oxide, RAW264.7 macrophages, Reactive oxygen species, Serotonin,
• MeSH
• antioxidancia farmakologie   MeSH
• cytokiny metabolismus   MeSH
• makrofágy metabolismus   MeSH
• melatonin farmakologie   MeSH
• myši MeSH
• oxid dusnatý metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• RAW 264.7 buňky MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• serotonin analogy a deriváty   farmakologie   MeSH
• zánět metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antioxidancia MeSH
• cytokiny MeSH
• melatonin MeSH
• N-acetylserotonin MeSH Prohlížeč
• oxid dusnatý MeSH
• reaktivní formy kyslíku MeSH
• serotonin MeSH