Phorbol 12-myristate 13-acetate Research Articles

The involvement of krüppel-like transcription factor 2 in megakaryocytic differentiation induction by phorbol 12-myrestrat 13-acetate

BackgroundMegakaryocytic differentiation is a complicated process regulated by a series of transcription factors in a context- and stage-dependent manner. Recent studies have suggested that krüppel-like transcription factor 2 (KLF2) is involved in the control of embryonic erythroid precursor cell differentiation and maturation. However, the function and mechanism of KLF2 in regulating megakaryocytic differentiation remain unclear.MethodsThe expression patterns of krüppel-like transcription factors (KLFs) during megakaryocytic differentiation were identified from public databases. Phorbol 12-myristate 13-acetate (PMA) treatment of the myeloid-erythroid-leukemic cell lines K562 and HEL were used as cellular megakaryocytic differentiation models. A lentiviral transduction system was utilized to achieve the goal of amplifying or reducing KLF2. The expression of KLF2 was examined using real-time PCR and western blot. The impact of KLF2 on the megakaryocytic differentiation of K562 cells was examined by flow cytometry, Giemsa staining, Phalloidin staining and western blot. RNA-sequencing (RNA-seq) and chromatin immunoprecipitation-sequencing (ChIP-seq) technologies were used to identify the KLF2-regulated targets.ResultsKLF2 is increased in the maturation process of megakaryocytes. KLF2 overexpression accelerated the PMA-induced megakaryocytic differentiation, as reflected by an increased percentage of CD41/CD61 cells, an increased number of polyploid cells, and an elevated expression of P21 and P27. KLF2 knockdown exhibited the opposite results, indicating that KLF2 knockdown suppressed the megakaryocytic differentiation. Further, combination of the RNA-seq and ChIP-seq results suggested that chimerin 1 (CHN1) and potassium voltage-gated channel subfamily Q member 5 (KCNQ5) may be target genes regulated of KLF2. Both CHN1 and KCNQ5 knockdown could block the megakaryocytic differentiation to some content.ConclusionThis study implicated a regulatory role of KLF2 in megakaryocytic differentiation, which may suggest KLF2 as a target for illness with abnormal megakaryocytic differentiation.

Inducible gene expression of IκB-kinase ε is dependent on nuclear factor-κB in human pulmonary epithelial cells.

While IκB-kinase-ε (IKKε) induces immunomodulatory genes following viral stimuli, its up-regulation by inflammatory cytokines remains under-explored. Since airway epithelial cells respond to airborne insults and potentiate inflammation, IKKε expression was characterized in pulmonary epithelial cell lines (A549, BEAS-2B) and primary human bronchial epithelial cells grown as submersion or differentiated air-liquid interface cultures. IKKε expression was up-regulated by the pro-inflammatory cytokines, interleukin-1β (IL-1β) and tumour necrosis factor-α (TNFα). Thus, mechanistic interrogations in A549 cells were used to demonstrate the NF-κB dependence of cytokine-induced IKKε. Furthermore, chromatin immunoprecipitation in A549 and BEAS-2B cells revealed robust recruitment of the NF-κB subunit, p65, to one 5' and two intronic regions within the IKKε locus (IKBKE). In addition, IL-1β and TNFα induced strong RNA polymerase 2 recruitment to the 5' region, the first intron, and the transcription start site. Stable transfection of the p65-binding regions into A549 cells revealed IL-1β- and TNFα-inducible reporter activity that required NF-κB, but was not repressed by glucocorticoid. While critical NF-κB motifs were identified in the 5' and downstream intronic regions, the first intronic region did not contain functional NF-κB motifs. Thus, IL-1β- and TNFα-induced IKKε expression involves three NF-κB-binding regions, containing multiple functional NF-κB motifs, and potentially other mechanisms of p65 binding through non-classical NF-κB binding motifs. By enhancing IKKε expression, IL-1β may prime, or potentiate, responses to alternative stimuli, as modelled by IKKε phosphorylation induced by phorbol 12-myristate 13-acetate. However, since IKKε expression was only partially repressed by glucocorticoid, IKKε-dependent responses could contribute to glucocorticoid-resistant disease.

Bacillus amyloliquefaciens Protect Against Atherosclerosis Through Alleviating Foam Cell Formation and Macrophage Polarization.

This study was to investigate the therapeutic effect of Bacillus amyloliquefaciens (Ba) on atherosclerosis (AS). THP-1 monocyte was differentiated to THP-1 macrophage (THP-M) through phorbol 12-myristate 13-acetate. After pre-treatment by 108cfu/ml Ba lasting 6h, THP-M was induced with 100mg/l ox-LDL lasting 48h to form macrophage foam cell (THP-F). RT-qPCR and flow cytometry were employed to determine the polarization of THP-M and THP-F. ApoE-/- mice with high-fat and high-cholesterol diet were used for constructing an AS model to evaluate the effect of Ba on AS. Our in vitro results showed that Ba vegetative cells pre-treatment distinctly inhibited the levels of iNOS and CD16/CD32 (M1 macrophage markers), and increased the levels of FIZZ1, Ym1, Arg1, CD163, and CD206 (M2 macrophage markers), indicating that Ba pre-treatment promoted anti-inflammatory M2-like polarization both in THP-M and THP-F. Meanwhile, it also suppressed cholesterol uptake, esterification, and hydrolysis, and efflux by THP-M and THP-F. Additionally, our animal experiments demonstrated that Ba vegetative cells treatment suppressed high cholesterol, hyperglycemia, hyperlipidemia, and the release of inflammatory factors (TNF-α, IL-6 and IL-1β) in ApoE-/- AS mice. In a word, our results indicated that Ba may protect against AS through alleviating foam cell formation and macrophage polarization through targeting certain stages of AS.

P-447 Dynamic changes in uterine natural killer cell (uNK) function across menstrual phases: Implications for implantation

Abstract Study question Does the function of uNK cells change from the proliferative stage of the menstrual cycle to the secretory phase in readiness for implantation? Summary answer During the secretory phase, uNK cells demonstrate an enhanced ability to produce cytokines indicating their importance for implantation. What is known already The abundance of uNK cells during implantation, and their secretion of trophoblast chemoattractant factors, suggests their pivotal role in placentation. uNK cells express Killer Immunoglobulin-like Receptors (KIR), which interact with Human Leukocyte Antigen-C (HLA-C) on trophoblasts, inducing cytokine production that aids trophoblast migration. It has recently been discovered that uNK cells consist of three distinct subsets, with different propensities to produce cytokines. However, the cytokine production abilities of each subset, and how this changes over the menstrual cycle, remains unexplored. Study design, size, duration A prospective cross-sectional study was conducted to compare uNK cell function between the proliferative and secretory phases of the menstrual cycle. The proliferative phase was defined as before day 14 of the menstrual cycle, and the secretory phase after this, in those with a regular 28-32 day menstrual cycle. The current data analysed is from 6 proliferative phase samples and 10 secretory phase samples however recruitment is ongoing. Participants/materials, setting, methods Endometrial samples were collected with a Pipelle biopsy from healthy fertile women attending the sexual health clinic for contraception. In the laboratory, endometrial lymphocytes were isolated and cultured with Anti-CD107a PerCP-eFlour710 (100ul/ml), Brefeldin (3ug/ml) and Monensin (2uM/ml). Cells were then stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin (2ul/ml) and incubated for 4 hours at 37 °C. Flow cytometry was employed to analyse the samples after staining with viability dye, cell surface antibodies, and intracellular markers. Main results and the role of chance In initial experiments, degranulation declined during the proliferative phase in both uNK2 and uNK3 compared to the other two phases of the menstrual cycle. There was a significant increase in the production of TNFa by uNK1 and IL-8 by uNK3 in the secretory phase compared to the proliferative phase. There were also increases in IFNg and GM-CSF production across all subsets although this did not reach significance (Statistical testing was done using Kruskal Wallis with a post-hoc Dunn test, p < 0.05). Current work explores the production of more recently identified trophoblast chemoattractants, including XCL1 and CSF1, which we would expect to increase in a similar manner. Limitations, reasons for caution Limitations include the cross-sectional nature of the study, limiting the ability to establish causation. However another study, tracking pregnancy outcomes in those with recurrent implantation failure aims to address this. Additionally, variations within menstrual phases may exist. The sample size is also a limitation which I am working to expand. Wider implications of the findings A comprehensive understanding of uNK throughout various menstrual phases holds profound implications for reproductive health. The heightened cytokine production observed during the secretory phase indicates their pivotal role in the process of implantation. This finding not only underscores their significance but also serves as a catalyst for further research. Trial registration number not applicable

Tigliane metabolites in Hyles frass after feeding experiments with TPA and Euphorbia cyparissias

AbstractWithin the genus Hyles, Euphorbia feeding appears to have evolved twice independently, in H. euphorbiae but also in H. nicaea, a species which had not been studied for its detoxification processes before. Euphorbia is known to contain toxic secondary metabolites, including diterpene esters, preventing most herbivores from feeding on them. We investigated the metabolisation of the standard phorbol ester Phorbol 12-myristate 13-acetate (TPA) and the diterpenes contained in Euphorbia cyparissias by the two species Hyles euphorbiae and Hyles nicaea (subspecies nicaea). For the first time, we report (1) The gut disposition of Hyles n. nicaea for this standard phorbol ester, which is commonly used in cancer and tumour research and (2) The disposition of the food plant tiglinaes of Euphorbia cyparissias after gut passage in both species and (3) Tigliane metabolites in the frass of TPA and of E. cyparissias feeding larvae. For both species around 5–25% of the TPA dose was recovered in the frass of the larvae, along with the metabolites phorbol and phorbol-13-acetate in very small amounts and traces. While the amounts of phorbol found did not differ much between the species frass, phorbol-13-acetate could be found in higher amounts in Hyles n. nicaea frass, indicating a difference in metabolisation. Moreover, enzymatic hydrolysis of TPA to phorbol-13-acetate and phorbol are postulated not to be the main metabolisation pathway, seeing that the amounts found only represent a small fraction of the TPA dose consumed.

Effects of Polyphenols and Lignans of Phyllanthus amarus Schumach. and Thonn. on IL-1β and TNF-α Secretions from LPS-induced THP-1-derived Macrophages

Background: Phyllanthus amarus exhibited immunosuppressive and anti-inflammatory effects in several in vitro and in vivo studies. However, there is no report on the inhibitory effects of its secondary metabolites on pro-inflammatory cytokines secretion from human THP-1-derived macrophages. background: Phyllanthus amarus exhibited immunosuppressive and anti-inflammatory effects in several in vitro and in vivo studies. However, there is no report on the inhibitory effects of its secondary metabolites on pro-inflammatory cytokines secretion from human THP-1-derived macrophages. Objective: The objective of this study was to correlate the polyphenols (ellagic acid (EA), gallic acid (GA), geraniin (GER), and corilagin (COR)) and lignans ((phyllanthin (PHY), hypophyllanthin (HYPO), niranthin (NIR), phyltetralin (PHYLT), and isolintetralin (ISO)) of 80% ethanol extract of P. amarus with their inhibitory effect against IL-1β and TNF-α secretions from LPS-induced THP-1- derived macrophages. Methods: Chemical profiling of P. amarus was carried out by LC-MS/MS analysis. Validated qualitative and quantitative reversed-phase HPLC analyses of the P. amarus extract were performed for the determination of lignan and polyphenol contents. Human THP-1-derived macrophages were prepared by treatment of THP-1 cells with phorbol 12-myristate 13-acetate (PMA). The inhibition of cytokines released by the extract, lignans and polyphenols in the cells was investigated using ELISA assay. method: Chemical profiling of P. amarus was carried out by LC-MS/MS analysis. Validated qualitative and quantitative reversed phase HPLC analyses of the P. amarus extract were performed for determination of lignan and polyphenol contents. Human THP-1 derived macrophages were prepared by treatment of THP-1 cells with phorbol 12-myristate 13-acetate (PMA). The inhibition of cytokines release by the extract, lignans and polyphenols in the cells were investigated using ELISA assay. Results: P. amarus extract and its chemical constituents significantly reduced the levels of IL-1β and TNF-α in a dose-dependent manner. At a dose of 50 μM, COR exhibited a maximum inhibition of 81.11% on TNF-α secretion, while GER showed 72.56% inhibition on IL-1β secretion. COR demonstrated the strongest inhibition of TNF-α secretion, exhibiting an IC50 value of 9.06 μM, which was comparable to that of dexamethasone (7.07 μM). Meanwhile, GER was the most potent against IL- 1β secretion, exhibiting an IC50 value of 20.09 μM. In the case of TNF-α secretion, the order of potency observed among the active compounds, with regard to IC50 value, was COR > GER > HYPO > PHY > NIR > GA > EA >ISO > PHYLT. For IL-1β secretion, the order of potency was GER > NIR > COR > GA > EA > PHY > HYPO > PHYLT > 1SO. Conclusion: The polyphenol contents of P. amarus, especially COR and GER, contributed significantly to the suppression of cytokines secretion, and they have the potential to be developed into agents for the treatment of pathologic inflammation.

The TAK1/JNK axis participates in adaptive immunity by promoting lymphocyte activation in Nile tilapia

The transforming growth factor beta-activated kinase 1 (TAK1) / c-Jun N-terminal kinase (JNK) axis is an essential MAPK upstream mediator and regulates immune signaling pathways. However, whether the TAK1/JNK axis harnesses the strength in regulation of signal transduction in early vertebrate adaptive immunity is unclear. In this study, by modeling on Nile tilapia (Oreochromis niloticus), we investigated the potential regulatory function of TAK1/JNK axis on lymphocyte-mediated adaptive immune response. Both OnTAK1 and OnJNK exhibited highly conserved sequences and structures relative to their counterparts in other vertebrates. Their mRNA was widely expressed in the immune-associated tissues, while phosphorylation levels in splenic lymphocytes were significantly enhanced on the 4th day post-infection by Edwardsiella piscicida. In addition, OnTAK1 and OnJNK were significantly up-regulated in transcriptional level after activation of lymphocytes in vitro by phorbol 12-myristate 13-acetate plus ionomycin (P+I) or PHA, accompanied by a predominant increase in phosphorylation level. More importantly, inhibition of OnTAK1 activity by specific inhibitor NG25 led to a significant decrease in the phosphorylation level of OnJNK. Furthermore, blocking the activity of OnJNK with specific inhibitor SP600125 resulted in a marked reduction in the expression of T-cell activation markers including IFN-γ, CD122, IL-2, and CD44 during PHA-induced T-cell activation. In summary, these findings indicated that the conserved TAK1/JNK axis in Nile tilapia was involved in adaptive immune responses by regulating the activation of lymphocytes. This study enriched the current knowledge of adaptive immunity in teleost and provided a new perspective for understanding the regulatory mechanism of fish immunity.

CPHEN-017: Comprehensive phenotyping of neutrophil extracellular traps (NETs) on peripheral human neutrophils.

With the recent discovery of their ability to produce neutrophil extracellular traps (NETs), neutrophils are increasingly appreciated as active participants in infection and inflammation. NETs are characterized as large, web-like networks of DNA and proteins extruded from neutrophils, and there is considerable interest in how these structures drive disease in humans. Advancing research in this field is contingent on developing novel tools for quantifying NETosis. To this end, we have developed a 7-marker flow cytometry panel for analyzing NETosis on human peripheral neutrophils following in vitro stimulation, and in fresh circulating neutrophils under inflammatory conditions. This panel was optimized on neutrophils isolated from whole blood and analyzed fresh or in vitro stimulated with phorbol 12-myristate 13-acetate (PMA) or ionomycin, two known NET-inducing agonists. Neutrophils were identified as SSChighFSChighCD15+CD66b+. Neutrophils positive for amine residues and 7-Aminoactinomycin D (7-AAD), our DNA dye of choice, were deemed necrotic (Zombie-NIR+7-AAD+) and were removed from downstream analysis. Exclusion of Zombie-NIR and positivity for 7-AAD (Zombie-NIRdim7-AAD+) was used here as a marker of neutrophil-appendant DNA, a key feature of NETs. The presence of two NET-associated proteins - myeloperoxidase (MPO) and neutrophil elastase (NE) - were utilized to identify neutrophil-appendant NET events (SSChighFSChighCD15+CD66b+Zombie NIRdim7-AAD+MPO+NE+). We also demonstrate that NETotic neutrophils express citrullinated histone H3 (H3cit), are concentration-dependently induced by in vitro PMA and ionomycin stimulation but are disassembled with DNase treatment, and are present in both chronic and acute inflammation. This 7-color flow cytometry panel provides a novel tool for examining NETosis in humans.

Lysophosphatidic Acid Receptor 3 (LPA3): Signaling and Phosphorylation Sites.

LPA3 receptors were expressed in TREx HEK 293 cells, and their signaling and phosphorylation were studied. The agonist, lysophosphatidic acid (LPA), increased intracellular calcium and ERK phosphorylation through pertussis toxin-insensitive processes. Phorbol myristate acetate, but not LPA, desensitizes LPA3-mediated calcium signaling, the agonists, and the phorbol ester-induced LPA3 internalization. Pitstop 2 (clathrin heavy chain inhibitor) markedly reduced LPA-induced receptor internalization; in contrast, phorbol ester-induced internalization was only delayed. LPA induced rapid β-arrestin-LPA3 receptor association. The agonist and the phorbol ester-induced marked LPA3 receptor phosphorylation, and phosphorylation sites were detected using mass spectrometry. Phosphorylated residues were detected in the intracellular loop 3 (S221, T224, S225, and S229) and in the carboxyl terminus (S321, S325, S331, T333, S335, Y337, and S343). Interestingly, phosphorylation sites are within sequences predicted to constitute β-arrestin binding sites. These data provide insight into LPA3 receptor signaling and regulation.

Deletion of pyruvate dehydrogenase kinases reduces susceptibility to deep vein thrombosis in mice

AbstractNeutrophils contribute to deep vein thrombosis (DVT) by releasing prothrombotic neutrophil extracellular traps (NETs). NET formation (known as NETosis) is an energy-intensive process that requires an increased rate of aerobic glycolysis. The metabolic enzymes pyruvate dehydrogenase kinases (PDKs) inhibit the pyruvate dehydrogenase complex to divert the pyruvate flux from oxidative phosphorylation toward aerobic glycolysis. Herein, we identified that the combined deletion of PDK2 and PDK4 (PDK2/4–/–) renders mice less susceptible to DVT (measured by thrombus incidence, weight, and length) in the inferior vena cava–stenosis model at day 2 after surgery. Compared with wild-type (WT) mice, the venous thrombus obtained from PDK2/4–/– mice exhibited reduced citrullinated histone content, a known marker of NETs. In line with in vivo observations, phorbol 12-myristate 13-acetate (PMA)–stimulated PDK2/4–/– neutrophils displayed reduced NETosis and secretion of cathepsin G and elastase compared with PMA-stimulated WT neutrophils. The formation of platelet aggregates mediated by PMA-stimulated PDK2/4–/– neutrophils were significantly reduced compared with PMA-stimulated WT neutrophils. Finally, PDK2/4–/– neutrophils exhibited reduced levels of intracellular Ca2+ concentration, extracellular signal-regulated kinase 1/2 (Erk1/2) phosphorylation, and glycolytic proton efflux rate (a measure of aerobic glycolysis), known to facilitate NETosis. Together, these findings elucidate, to our knowledge, for the first time, the fundamental role of PDK2/4 in regulating NETosis and acute DVT.

HIV-1 latency reversal agent boosting is not limited by opioid use.

The opioid epidemic may impact the HIV-1 reservoir and its reversal from latency in virally suppressed people with HIV (PWH). We studied forty-seven PWH and observed that lowering the concentration of HIV-1 latency reversal agents (LRA), used in combination with small molecules that do not reverse latency, synergistically increases the magnitude of HIV-1 re-activation ex vivo, regardless of opioid use. This LRA boosting, which combines a Smac mimetic or low-dose protein kinase C agonist with histone deacetylase inhibitors, can generate significantly more unspliced HIV-1 transcription than phorbol 12-myristate 13-acetate (PMA) with ionomycin (PMAi), the maximal known HIV-1 reactivator. LRA boosting associated with greater histone acetylation in CD4+ T cells and modulated T cell activation-induced markers and intracellular cytokine production; Smac mimetic-based boosting was less likely to induce immune activation. We found that HIV-1 reservoirs in PWH contain unspliced and polyadenylated (polyA) virus mRNA, the ratios of which are greater in resting than total CD4+ T cells and can correct to 1:1 with PMAi exposure. Latency reversal results in greater fold-change increases to HIV-1 poly(A) mRNA than unspliced message. Multiply spliced HIV-1 transcripts and virion production did not consistently increase with LRA boosting, suggesting the presence of a persistent post-transcriptional block. LRA boosting can be leveraged to probe the mechanisms of an effective cellular HIV-1 latency reversal program.

Direct and macrophage stimulation mediated effects of active, inactive, and cell-free supernatant forms of Akkermansia muciniphila and Faecalibacterium duncaniae on hepcidin gene expression in HepG2 cells.

Hepcidin is a crucial regulator of iron homeostasis with protective effects on liver fibrosis. Additionally, gut microbiota can also affect liver fibrosis and iron metabolism. Although the hepatoprotective potential of Akkermansia muciniphila and Faecalibacterium duncaniae, formerly known as F. prausnitzii, has been reported, however, their effects on hepcidin expression remain unknown. We investigated the direct and macrophage stimulation-mediated effects of active, heat-inactivated, and cell-free supernatant (CFS) forms of A. muciniphila and F. duncaniae on hepcidin expression in HepG2 cells by RT-qPCR analysis. Following stimulation of phorbol-12-myristate-13-acetate (PMA) -differentiated THP-1 cells with A. muciniphila and F. duncaniae, IL-6 concentration was assessed via ELISA. Additionally, the resulting supernatant was treated with HepG2 cells to evaluate the effect of macrophage stimulation on hepcidin gene expression. The expression of genes mediating iron absorption and export was also examined in HepG2 and Caco-2 cells via RT-qPCR. All forms of F. duncaniae increased hepcidin expression while active and heat-inactivated/CFS forms of A. muciniphila upregulated and downregulated its expression, respectively. Active, heat-inactivated, and CFS forms of A. muciniphila and F. duncaniae upregulated hepcidin expression, consistent with the elevation of IL-6 released from THP-1-stimulated cells as a macrophage stimulation effect in HepG2 cells. A. muciniphila and F. duncaniae in active, inactive, and CFS forms altered the expression of hepatocyte and intestinal iron-mediated absorption /exporter genes, namely dcytb and dmt1, and fpn in HepG2 and Caco-2 cells, respectively. In conclusion, A. muciniphila and F. duncaniae affect not only directly but also through macrophage stimulation the expression of hepcidin gene in HepG2 cells. These findings underscore the potential of A. muciniphila and F. duncaniae as a potential therapeutic target for liver fibrosis by modulating hepcidin and intestinal and hepatocyte iron metabolism mediated gene expression.

Resveratrol and piceid enhance efferocytosis by increasing the secretion of MFG-E8 in human THP-1 macrophages.

The process of apoptotic cell clearance by phagocytes, known as efferocytosis, plays an essential role in maintaining homeostasis. Defects in efferocytosis can lead to inflammatory diseases such as atherosclerosis and autoimmune disorders. Therefore, the maintenance and promotion of efferocytosis are considered crucial for preventing these diseases. In this study, we observed that resveratrol, a representative functional food ingredient, and its glycoside, piceid, promoted efferocytosis in both human THP-1 macrophages differentiated with phorbol 12-myristate 13-acetate and peritoneal macrophages from thioglycolate-elicited mice. Resveratrol and piceid significantly increased mRNA expression and protein secretion of MFG-E8 in THP-1 macrophages. Furthermore, the activation of efferocytosis and the increment in MFG-E8 protein secretion caused by resveratrol or piceid treatment were canceled by MFG-E8 knockdown in THP-1 macrophages. In conclusion, we have demonstrated for the first time that resveratrol and piceid promote efferocytosis through the upregulation of MFG-E8 excretion in human THP-1 macrophages.

PECULIARITIES OF NEUTROPHIL EXTRACELLULAR TRAPS FORMATION IN CHINCHILLA RABBITS

Neutrophil extracellular traps (NETs) are decondensed nuclear chromatin, decorated with bactericidal proteins of various cell organelles and performing an eff ector function aimed to combat pathogens at the site of infl ammation. At the same time, NETs play an important role in the pathogenesis of many autoimmune and infl ammatory diseases as well as malignancies. Rabbits are one of the most commonly used species of laboratory animals in medical and biological research. A large number of models of various diseases of the cardiovascular, immune and other human systems have been developed in rabbits. However, there is no information in the scientifi c literature about the ability of rabbit neutrophils to undergo NETosis in response to well-known pharmacological stimuli. The purpose of the present work was to study in in vitro system the ability of neutrophils of Soviet chinchilla rabbit to form NETs in response to mimetic of diacylglycerol phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187. To isolate rabbit neutrophils, the one-step density gradient centrifugation on Ficoll-Hypaque method with modifi cations was used. Oxidative burst was assessed with luminol-amplifi ed chemiluminescence method, and NET formation was assessed with immunofl uorescence analysis. The work shows for the fi rst time that neutrophils of Soviet chinchilla rabbit do not form NETs in response to PMA, but form traps in response to A23187, as well as have a low level of oxidative burst in response to PMA, A23187 and chemoattractant N-formyl-methionylleucyl-phenylalanine.

PECULIARITIES OF NEUTROPHIL EXTRACELLULAR TRAPS FORMATION IN CHINCHILLA RABBITS

Neutrophil extracellular traps (NETs) are decondensed nuclear chromatin, decorated with bactericidal proteins of various cell organelles and performing an eff ector function aimed to combat pathogens at the site of infl ammation. At the same time, NETs play an important role in the pathogenesis of many autoimmune and infl ammatory diseases as well as malignancies. Rabbits are one of the most commonly used species of laboratory animals in medical and biological research. A large number of models of various diseases of the cardiovascular, immune and other human systems have been developed in rabbits. However, there is no information in the scientifi c literature about the ability of rabbit neutrophils to undergo NETosis in response to well-known pharmacological stimuli. The purpose of the present work was to study in in vitro system the ability of neutrophils of Soviet chinchilla rabbit to form NETs in response to mimetic of diacylglycerol phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187. To isolate rabbit neutrophils, the one-step density gradient centrifugation on Ficoll-Hypaque method with modifi cations was used. Oxidative burst was assessed with luminol-amplifi ed chemiluminescence method, and NET formation was assessed with immunofl uorescence analysis. The work shows for the fi rst time that neutrophils of Soviet chinchilla rabbit do not form NETs in response to PMA, but form traps in response to A23187, as well as have a low level of oxidative burst in response to PMA, A23187 and chemoattractant N-formyl-methionylleucyl-phenylalanine.

Short Communication: Goat Mastitis and the Formation of Neutrophil Extracellular Traps (NETs)

Mastitis, an inflammation of the mammary gland affecting milk production and quality in dairy herds, is often associated with Staphylococcus spp. in goats. Neutrophils are crucial in combating infections by migrating into milk and deploying various defense strategies, including the release of neutrophil extracellular traps (NETs) composed of DNA, histones, and bactericidal proteins. This study investigated whether NETs are released by goat neutrophils stimulated in vitro by Staphylococcus aureus and Staphylococcus warneri, two common pathogens of goat mastitis. PMNs were isolated from blood from healthy adult goats. We evaluated goat NET formation by stimulating cells with: phorbol 12-myristate 13-acetate (PMA) as a positive control, cytochalasin for inhibition of actin polymerization, S. aureus, and S. warneri. NET formation was observed in response to chemical stimulation and bacterial presence, effectively trapping pathogens. Variations in NET formation between S. aureus and S. warneri suggest pathogen-specific responses. These findings suggest that the formation of NETs may be an important complementary mechanism in the defense against mastitis in goats. In conclusion, this study unveils a novel defense mechanism in goats, indicating the role of NETs against S. aureus and S. warneri in mastitis.

First-in-human study of HMPL-295, an ERK1/2 inhibitor, in patients with advanced solid tumors: Dose-escalation results of monotherapy.

e15112 Background: HMPL-295 (’295) is an extracellular signal-regulated kinase 1 and 2 (ERK1/2) inhibitor with potent activity in non-clinical studies. This is a first-in-human, dose escalation study of ’295 in patients (pts) with advanced solid tumors. Here, we report the results of the mono dose escalation stage. Methods: Pts with advanced solid tumors who have failed standard therapy were enrolled to receive ’295 once daily (QD) in 28-day cycles or ’295 QD 2 weeks on/1 week off (2w on/1w off) in 21-day cycles. The mTPI-2 design was used for dose escalation, having explored from 5 to 75 mg QD in 6 cohorts, as well as 75 mg and 100 mg QD 2w on/1w off. The study aims to determine the maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D), safety, tolerability, pharmacokinetics/pharmacodynamics (PK/PD), and preliminary efficacy (best of response, BOR). Results: As of Dec 11, 2023, 47 pts with advanced solid tumors were enrolled (n=1, 1, 3, 6, 12, 5, 13, 6 in 5, 10, 20, 40, 50, 75 mg QD cohorts, 75, 100 mg QD 2w on/1w off cohorts, respectively), with a median age of 58 years, 23 (48.9%) male pts. During the dose escalation from 5 to 75 mg QD cohort, 1 pt given 40 mg QD experienced a dose-limiting toxicity (DLT) of grade 3 dermatitis acneiform and 2 pts given 75 mg QD experienced DLTs of grade 3 rash and acute kidney injury (AKI). As for intermittent-administration cohorts, 2 pts given 100 mg QD 2w on/1w off experienced DLTs of grade 3 AKI and rash maculo-papular. After multiple-dose oral administration, ’295 plasma concentrations reach peak at 1.0-2.0 hours post dose and the exposure (Cmax and AUC) displayed dose dependent increase. The accumulation ratio (AUC) was 2.1–3.4 after repeat dosing, reaching steady-state around day 15. ’295 inhibited ribosomal S6 kinase (RSK) phosphorylation which is a downstream signaling molecule regulated by ERK1/2 and stimulated by phorbol 12-myristate 13-acetate (PMA). The BOR was partial response each in 1 pt with duodenal adenocarcinoma in 40 mg QD cohort,1 pt with endometrial cancer in 50 mg QD cohort and 1 pt with non-small cell lung cancer (NSCLC) in 75 mg QD 2w on/1w off cohort. Stable disease with tumor shrinkage was also observed in 2 pts with NSCLC on 50 mg QD and 75 mg QD 2w on/1w off cohort respectively, and 1 pt with pancreatic ductal adenocarcinoma in 100 mg QD 2w on/1w off cohort. 25 (53.2%) pts reported grade ≥3 TEAEs. The most common (≥10.0%) ≥ grade 3 TEAEs were rash (10.6%) and anemia (10.6%). Conclusions: Considering safety, tolerability, PK/PD and preliminary efficacy results, RP2D was determined to be 50 mg QD. Clinical trial information: NCT04908046 .

Non-invasive Physical Plasma Modulates Macrophage Polarization: A Potential Strategy for Tumor Microenvironment Remodeling.

Non-invasive physical plasma (NIPP) has shown promise in the treatment of cancer. However, conflicting results have been reported regarding the effect of NIPP on macrophage polarization. As tumor-associated macrophages (TAMs) are essential in the regulation of cancer development, this study aimed to determine the role of NIPP treatment in macrophage polarization and tumor-microenvironment (TME) remodeling. A portable NIPP device, Plasma Care (Terraplasma Medical, Garching, Germany), was employed as the source of NIPP. The human monocytic cell line THP-1 was adopted as the cell model for macrophage differentiation and polarization. The effects of NIPP treatment on temperature, pH value, and oxidative stress induction of the culture medium were examined to validate the feasibility of applying the NIPP device in subsequent cell treatment. The changes in morphology, viability, and proliferation of THP-1 cells after NIPP treatment were determined. The expression of M1/M2 macrophage markers was examined by real-time quantitative polymerase chain reaction. No significant changes were observed in temperature and pH value after NIPP treatment, while the formation of hydrogen peroxide was promoted in a time-dependent manner. Cell morphology, viability, and proliferation were not affected by up to 6 minutes of NIPP treatment. In monocytes, 6 minutes of NIPP treatment significantly increased the expression of M1 markers (TNF-α and IL-6) and suppressed the M2 marker (CD206), findings which were consistent in the monocyte-derived macrophages. Furthermore, NIPP treatment also significantly promoted M1 polarization in the monocyte-derived macrophages induced by phorbol 12-myristate 13-acetate. NIPP is a safe and robust oxidative stress inducer and showed potential in TAM regulation by promoting M1 macrophage polarization.

Ameliorative effects of Wikstroemia trichotoma 95% EtOH extract on a mouse model of DNCB-induced atopic dermatitis

Ethnopharmacological relevanceThe genus Wikstroemia has been extensively utilized in traditional Chinese medicine (TCM) for the management of conditions such as coughs, edema, arthritis, and bronchitis. Studies have indicated that the crude extracts of Wikstroemia exhibit anti-inflammatory, anti-allergy, anti-aging, skin psoriasis, anti-cancer, and antiviral properties. In addition, these extracts are known to contain bioactive substances, including flavonoids, coumarins, and lignans. However, few studies have investigated the anti-inflammatory or anti-allergic activities of Wikstroemia trichotoma (Thunb.) Makino against atopic dermatitis (AD). Aim of the studyThe study aimed to explore the potential of a 95% ethanol extract of W. trichotoma (WTE) on the dysfunction of skin barrier and immune system, which are primary symptoms of AD, in 2,4-dinitrochlorobenzene (DNCB)-induced SKH-1 hairless mice and phorbol 12-myristate 13-acetate (PMA)/ionomycin or immunoglobulin E (IgE) + 2,4-dinitrophenylated bovine serum albumin (DNP-BSA) stimulated rat basophilic leukemia cell line (RBL-2H3). Furthermore, we sought to identify the chemical contents of WTE using high-performance liquid chromatography equipped with a photodiode array detector (HPLC-PDA). Materials and methodsAn in vitro study was conducted using RBL-2H3 cells stimulated with PMA/ionomycin or IgE + DNP-BSA to assess the inhibitory effects of WTE on mast cell degranulation and interleukin-4 (IL-4) mRNA expression levels. For the in vivo study, AD was induced in SKH-1 hairless mice by applying 1% DNCB to the dorsal skin daily for 7 days. Subsequently, 0.1% DNCB solution was applied on alternate days, and mice were orally administered WTE (at 30 or 100 mg/kg/day) dissolved in 0.5% carboxymethyl cellulose (CMC) daily for 2 weeks. Transepidermal water loss (TEWL), skin hydration, skin pH, and total serum IgE levels were measured. ResultsIn DNCB-stimulated SKH-1 hairless mice, WTE administration significantly improved AD symptoms and ameliorated dorsal skin inflammation. Oral administration of WTE led to a significant decrease in skin thickness, infiltration of mast cells, and level of total serum IgE, thus restoring skin barrier function in the DNCB-induced skin lesions. In addition, WTE inhibited β-hexosaminidase release and reduced IL-4 mRNA levels in RBL-2H3 cells. Chemical profile analysis of WTE confirmed the presence of three phenolic compounds, viz. chlorogenic acid, miconioside B, and matteucinol-7-O-β-apiofuranosyl (1 → 6)-β-glucopyranoside. ConclusionsWTE ameliorates AD symptoms by modulating in the skin barrier and immune system dysfunction. This suggests that W. trichotoma extract may offer therapeutic benefits for managing AD.

Decreased atherosclerosis and abdominal aortic aneurysm in mice deficient in polymeric immunoglobulin receptor

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): La Caixa Banking Foundation and Comunidad de Madrid Background Polymeric immunoglobulin receptor (PIGR) is a transmembrane protein involved in the transcytosis of polymeric immunoglobulins that is widely expressed in mucosal epithelial cells. Recent data from our group described increased PIGR levels in plasma and tissue of atherosclerotic subjects. However, the role for PIGR in the mechanisms involved in vascular remodeling has not been addressed. Purpose To analyse the role for PIGR in experimental mouse models of atherosclerosis and abdominal aortic aneurysm (AAA). Methods We analyzed PIGR expression, secretion and distribution in early atherosclerotic plaques and AAA tissues compared to healthy aortic samples, as well as in macrophages derived from the human monocytic THP-1 cell line. Next, we studied the effect of global PIGR deficiency in experimental atherosclerosis (Ldlr-/- Pigr-/- mice fed with atherogenic diet for 10 weeks). In addition, the contribution of hematopoietic PIGR was assessed in both experimental atherosclerosis and AAA (Ldlr-/- mice fed with atherogenic diet and 1 µg/Kg/min angiotensin II infusion for 28 days) by bone marrow transplantation experiments. Finally, bone marrow-derived macrophages (BMDMs) from Pigr-/- and control mice were isolated to assess their inflammatory expression profile and modulation of polarization in response to oxidized LDL (ox-LDL), as well as their ability to promote foam cell formation. Results PIGR expression was increased in the intima of early human atherosclerotic lesions and showed colocalization with CD68+ expression. PIGR expression was also increased during the in vitro differentiation of THP-1 monocytes to macrophages with phorbol myristate acetate. Both global and hematopoietic-specific PIGR deficient mice displayed reduced plaque size in the aortic sinuses as well as a strong decrease in macrophage infiltration (CD68+ cells), while no changes in smooth muscle cells (α-SMA+ cells) and collagen content were observed. Regarding AAA, increased PIGR levels were found in human AAA tissues, associated with infiltrating CD68+ cells. PIGR deficiency in hematopoietic cells also showed significantly reduced AAA dilatation and reduced macrophage infiltration. In vitro experiments with BMDMs obtained from Pigr-/- mice and stimulated with ox-LDL showed reduced proinflammatory gene expression (TNF-a and IL-6) and M1 markers (iNOS and CD11c) as well as diminished foam cell formation. Conclusions PIGR deficiency in hematopoietic cells decreases atherosclerosis and AAA progression by modulating macrophage inflammatory responses, suggesting a novel proinflammatory role for PIGR in vascular pathologies. Future experiments will test the potential therapeutic effect of modulating PIGR to dampen the inflammatory profile in vascular diseases.Results in human and mouse studies