Is there an inflammatory stimulus to human term labour?

Inflammation is thought to play a pivotal role in the onset of term and some forms of preterm labour. Although, we recently found that myometrial inflammation is a consequence rather than a cause of term labour, there are several other reproductive tissues, including amnion, choriodecidua parietalis and decidua basalis, where the inflammatory stimulus to labour may occur. To investigate this, we have obtained amnion, choriodecidual parietalis and decidua basalis samples from women at various stages of pregnancy and spontaneous labour. The inflammatory cytokine profile in each tissue was determine by Bio-Plex Pro® cytokine multiplex assays and quantitative RT-PCR. Active motif assay was used to study transcription activation in the choriodecidua parietalis. Quantitative RT-PCR was use to study the pro-labour genes (PGHS-2, PGDH, OTR and CX43) in all of the tissues at the onset of labour and oxytocin (OT) mRNA expression in the choriodecidual parietalis and decidua basalis. Statistical significance was ascribed to a P value <0.05. In the amnion and choriodecidua parietalis, the mRNA levels of various cytokines decreased from preterm no labour to term no labour samples, but the protein levels were unchanged. The choriodecidua parietalis showed increase in the protein levels of IL-1β and IL-6 in the term early labour samples. In the amnion and decidua basalis, the protein levels of several cytokines rose in term established labour. The multiples of the median derived from the 19-plex cytokine assay were greater in term early labour and term established labour samples from the choriodecidua parietalis, but only in term established labour for myometrium. These data suggest that the inflammatory stimulus to labour may begin in the choriodecidua parietalis, but the absence of any change in prolabour factor mRNA levels suggests that the cytokines may act on the myometrium where we observed changes in transcription factor activation and increases in prolabour gene expression in earlier studies.

The loss of enzymatic activity of the PHARC associated lipase ABHD12 results in increased phagocytosis that causes neuroinflammation

Phagocytosis is an important evolutionary conserved process, essential for clearing pathogens and cellular debris in higher organisms, including humans. This well-orchestrated innate immunological response is intricately regulated by numerous cellular factors, important amongst which, are the immunomodulatory lysophosphatidylserines (lyso-PSs) and the pro-apoptotic oxidized phosphatidylserines (PSs) signaling lipids. Interestingly, in mammals, both these signaling lipids are physiologically regulated by the lipase ABHD12, mutations of which, cause the human neurological disorder PHARC. Despite the biomedical significance of this lipase, detailed mechanistic studies and the specific contribution of ABHD12 to innate processes like phagocytosis remain poorly understood. Here, by immunohistochemical and immunofluorescence approaches, using the murine model of PHARC, we show, that upon an inflammatory stimulus, activated microglial cells in the cerebellum of mice deficient in ABHD12 have an amoeboid morphology, increased soma size, and display heightened phagocytosis activity. We also report that upon an inflammatory stimulus, cerebellar levels of ABHD12 increase to possibly metabolize the heightened oxidized PS levels, temper phagocytosis and in turn control neuroinflammation during oxidative stress. Next, to complement these findings, using biochemical approaches in cultured microglial cells, we show that the pharmacological inhibition and/or genetic deletion of ABHD12 results in increased phagocytic uptake in a fluorescent bead uptake assay. Together, our studies provide compelling evidence that ABHD12 plays an important role in regulating phagocytosis in cerebellar microglial cells, and provides a possible explanation, as to why human PHARC subjects display neuroinflammation and atrophy in the cerebellum.

Ivacaftor partially corrects airway inflammation in a humanized G551D rat

Animal models have been highly informative for understanding the pathogenesis and progression of cystic fibrosis (CF) lung disease. In particular, the CF rat models recently developed have addressed mechanistic causes of the airway mucus defect characteristic of CF, and how these may change when CFTR activity is restored using new modulator therapies. We hypothesized that inflammatory changes to the airway would develop spontaneously and progressively, and that these changes would be resolved with modulator therapy. To test this, we used a humanized-CFTR rat expressing the G551D variant that responds to the CFTR modulator ivacaftor. Markers typically found in the CF lung were assessed, including neutrophil influx, small airway histopathology, and inflammatory cytokine concentration. Young hG551D rats did not express inflammatory cytokines at baseline but did upregulate these in response to inflammatory trigger. As the hG551D rats aged, histopathology worsened, accompanied by neutrophil influx into the airway and increasing concentrations of TNF-α, IL-1α, and IL-6 in the airways. Ivacaftor administration reduced concentrations of these cytokines when administered to the rats at baseline but was less effective in the rats that had also received inflammatory stimulus. Therefore, we conclude that administration of ivacaftor resulted in an incomplete resolution of inflammation when rats received an external trigger, suggesting that CFTR activation may not be enough to resolve inflammation in the lungs of patients with CF.

The inflammatory response induced by Pseudomonas aeruginosa in macrophages enhances apoptotic cell removal

Pathogens phagocytosis and the uptake of apoptotic cells (efferocytosis) are essential macrophages tasks, classically considered as mutually exclusive. Macrophages have been observed to polarize into either pro-inflammatory/microbicidal or anti-inflammatory/efferocytic phenotypes. However, macrophage functions have shown to be more complex. Furthermore, little is known about the regulation of efferocytosis under inflammatory conditions. In this study, we elucidate the modulation of the macrophage efferocytic function during an inflammatory stimulus. We find that bone marrow-derived macrophages (BMDM) are very efficient in engulfing both the bacterial pathogen Pseudomonas aeruginosa and apoptotic cells. BMDM showed a high bactericidal capacity unaffected by the concomitant presence of apoptotic material. Plasticity in macrophage programming, in response to changing environmental cues, may modulate efferocytic capability. In this work, we further show that, after phagocyting and processing Pseudomonas aeruginosa, macrophages highly increase their efferocytic capacity without affecting their phagocytic function. Moreover, we demonstrate that Pseudomonas aeruginosa enhances efferocytosis of these phagocytes through the IL-6 signaling pathway. Our results show that the inflammatory response generated by the bacterial processing enhances these macrophages’ capacity to control inflammation through an increased efferocytosis.

The Immunomodulatory Potential of Copper and Silver Based Self-Assembled Metal Organic Biohybrids Nanomaterials in Cancer Theranostics

Copper high aspect ratio structures (CuHARS) and silver cystine nanoparticles (AgCysNPs) are two unique micro/nano particles under study here that show extensive anti-cancer effects on a glioma tumor cell line. These micro/nano particles have shown potent toxicity in the presence of inflammatory stimulus (combination of tumor necrosis factor, [TNF] and lipo-polysaccharide, LPS). CuHARS with a concentration of 20 μg/ml uniquely increased the catalytic generation of nitric oxide (NO), an important contributor in the immune system. This NO was generated in a cell culture tumor microenvironment (TME) in the presence of 25 µM S-nitrosothiol (cysteine-NO) and the inflammatory stimulus. CuHARS increased the NO production by 68.75% when compared to untreated glioma cells with CysNO and inflammatory stimulus. The production of NO was significantly higher under similar circumstances in the case of normal primary structural cells like brain microvascular endothelial cells (BMVECs). The production of NO by BMVECs went up by 181.25% compared to glioma cells. This significant increase in the NO concentration could have added up to tumorigenesis but the anti-cancer effect of CuHARS was prominent enough to lower down the viability of glioma cells by approximately 20% and increased the metabolism of structural cells, BMVECs by approximately 200%. The immunomodulatory effect of NO in the TME under these circumstances in the presence of the novel micro/nano material, CuHARS has risen up compared to the effect of inflammatory stimulus alone. The potency and specific nature of these materials toward tumor cells may make them suitable candidates for cancer treatment. Successive treatment of CuHARS to glioma cells also proved to be an effective approach considering the decrease in the total count of cells by 11.84 fold in case of three successive treatments compared to a single dose which only decreased the cell count by 2.45 fold showing the dose-dependent increasing toxicity toward glioma cells. AgCysNPs are another potent nanomaterial which also proved its significant toxic nature toward tumor cell lines as demonstrated here, but their immunomodulatory response is still unclear and needs to be explored further.