Characteristics of the Alternative Phenotype of Microglia/Macrophages and its Modulation in Experimental Gliomas

Microglia (brain resident macrophages) accumulate in malignant gliomas and instead of initiating the anti-tumor response, they switch to a pro-invasive phenotype, support tumor growth, invasion, angiogenesis and immunosuppression by release of cytokines/chemokines and extracellular matrix proteases. Using immunofluorescence and flow cytometry, we demonstrate an early accumulation of activated microglia followed by accumulation of macrophages in experimental murine EGFP-GL261 gliomas. Those cells acquire the alternative phenotype, as evidenced by evaluation of the production of ten pro/anti-inflammatory cytokines and expression profiling of 28 genes in magnetically-sorted CD11b+ cells from tumor tissues. Furthermore, we show that infiltration of implanted gliomas by amoeboid, Iba1-positive cells can be reduced by a systematically injected cyclosporine A (CsA) two or eight days after cell inoculation. The up-regulated levels of IL-10 and GM-CSF, increased expression of genes characteristic for the alternative and pro-invasive phenotype (arg-1, mt1-mmp, cxcl14) in glioma-derived CD11b+ cells as well as enhanced angiogenesis and tumor growth were reduced in CsA-treated mice. Our findings define for the first time kinetics and biochemical characteristics of glioma-infiltrating microglia/macrophages. Inhibition of the alternative activation of tumor-infiltrating macrophages significantly reduced tumor growth. Thus, blockade of microglia/macrophage infiltration and their pro-invasive functions could be a novel therapeutic strategy in malignant gliomas

Many Labs 2: Investigating Variation in Replicability Across Samples and Settings

We conducted preregistered replications of 28 classic and contemporary published findings, with protocols that were peer reviewed in advance, to examine variation in effect magnitudes across samples and settings. Each protocol was administered to approximately half of 125 samples that comprised 15,305 participants from 36 countries and territories. Using the conventional criterion of statistical significance (p < .05), we found that 15 (54%) of the replications provided evidence of a statistically significant effect in the same direction as the original finding. With a strict significance criterion (p < .0001), 14 (50%) of the replications still provided such evidence, a reflection of the extremely highpowered design. Seven (25%) of the replications yielded effect sizes larger than the original ones, and 21 (75%) yielded effect sizes smaller than the original ones. The median comparable Cohen’s ds were 0.60 for the original findings and 0.15 for the replications. The effect sizes were small (< 0.20) in 16 of the replications (57%), and 9 effects (32%) were in the direction opposite the direction of the original effect. Across settings, the Q statistic indicated significant heterogeneity in 11 (39%) of the replication effects, and most of those were among the findings with the largest overall effect sizes; only 1 effect that was near zero in the aggregate showed significant heterogeneity according to this measure. Only 1 effect had a tau value greater than .20, an indication of moderate heterogeneity. Eight others had tau values near or slightly above .10, an indication of slight heterogeneity. Moderation tests indicated that very little heterogeneity was attributable to the order in which the tasks were performed or whether the tasks were administered in lab versus online. Exploratory comparisons revealed little heterogeneity between Western, educated, industrialized, rich, and democratic (WEIRD) cultures and less WEIRD cultures (i.e., cultures with relatively high and low WEIRDness scores, respectively). Cumulatively, variability in the observed effect sizes was attributable more to the effect being studied than to the sample or setting in which it was studied.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

Research on the Concept of Hydrogen Supply Chains and Power Grids Powered by Renewable Energy Sources: A Scoping Review with the Use of Text Mining

The key direction of political actions in the field of sustainable development of the energy sector and economy is the process of energy transformation (decarbonization) and increasing the share of renewable energy sources (RES) in the supply of primary energy. Regardless of the indisputable advantages, RES are referred to as unstable energy sources. A possible solution might be the development of the concept of hydrogen supply chains, especially the so-called green hydrogen obtained in the process of electrolysis from electricity produced from RES. The aim of the research undertaken in the article is to identify the scope of research carried out in the area of hydrogen supply chains and to link this research with the issues of the operation of electricity distribution networks powered by RES. As a result of the scoping review, and the application of the text-mining method using the IRaMuTeQ tool, which includes the analysis of the content of 12 review articles presenting the current research achievements in this field over the last three years (2016–2020), it was established that the issues related to hydrogen supply chains, including green hydrogen, are still not significantly associated with the problem of the operation of power grids. The results of the conducted research allow formulating recommendations for further research areas

Association of Metallic and Nonmetallic Elements with Fibrin Clot Properties and Ischemic Stroke

Objectives—Metallic elements and fibrin clot properties have been linked to stroke. We examined metallic and nonmetallic elements, fibrin clot lysis time (CLT), and maximum absorbance (Absmax) in relation to ischemic stroke. Design—A case–control study of ischemic stroke patients vs. healthy individuals. Subjects and Methods—Plasma and serum were collected from 260 ischemic stroke patients (45.0% women; age, 68 ± 12 years) and 291 healthy controls (59.7% women; age, 50 ± 17 years). Fibrin CLT and Absmax were measured using a validated turbidimetric assay. Serum elements were quantified by inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). Data were analyzed by bivariate correlations and multiple or logistic regression. Results—In female stroke patients, copper, lithium, and aluminum were significantly lower compared with controls; in male stroke patients, potassium was lower, and beryllium was elevated. In female and male stroke patients, iron, zinc, nickel, calcium, magnesium, sodium, and silicon were significantly lower, while strontium was elevated. Positive correlations between fibrin clot properties and metals, observed in healthy controls, were lost in ischemic stroke patients. In multivariate regression analysis, fibrin CLT and/or Absmax was associated with zinc, calcium, potassium, beryllium, and silicon in stroke patients and with sodium, potassium, beryllium, and aluminum in controls. In logistic regression analysis, stroke was independently associated with lithium, nickel, beryllium, strontium, boron, and silicon and with sodium, potassium, calcium, and aluminum but not with fibrin CLT/Absmax. Conclusions—Various elements were associated with fibrin clot properties and the risk of ischemic stroke. Lithium, sodium, calcium, and aluminum abrogated the association of fibrin clot properties with ischemic stroke

Influx of microglia/macrophages into the tumor is blocked by CsA.

<p>A. Representative confocal images of Iba1 staining in intact brain tissue, tumor-bearing brain slices from mice treated with PBS or CsA. Scale bar = 20 µm. B–C. Quantification of microglia and blood-derived macrophages in naïve, tumor-bearing and CsA-treated mice (4 per group). Each bar represents the mean ± SEM. ^***<i>p</i><0.001, ^**<i>p</i><0.01 tumor-bearing versus naïve mice; ^##<i>p</i><0.01, CsA-treated versus PBS-treated tumor-bearing mice.</p

Quantification of selected M1/M2 phenotype-associated gene expression in CD11b⁺ cells isolated from naïve and tumor-bearing mice.

<p>Gene expression was analyzed by real-time PCR and the results are presented as fold changes of CD11b⁺ cells isolated from tumor brains versus those from naïve brain tissue. Numbers corresponding to the significantly changed genes (t-test generated p-value<0.05) are marked in bold; NA - not available.</p

Alterations of gene expression in infiltrating microglia/macrophages and intracranial gliomas are modulated by CsA.

<p>A. Gene expression in magnetically sorted CD11b⁺ cells from tumor-bearing and naïve brains was determined by qPCR. Expression of five genes was significantly altered in CD11b⁺ cells: <i>arg-1 (p = 0.000003)</i>; <i>cxcl14 (p = 0.0001)</i>; <i>ifn-β1 (p = 0.0002)</i>; <i>cox-2 (p = 0.000002)</i>; <i>mt1-mmp (p = 0.00002)</i>; n = 5 animals per group; ^*<i>p</i><0.05, ^**<i>p</i><0.01. The middle line represents the median value. Lower ΔC_T are consistent with higher gene expression. B. Quantification of arginase activity in brain tissue extracts from naïve and tumor-bearing mice treated either with PBS or CsA. Results represent the mean ± SEM of 4–5 mice; ^*<i>p</i><0.05, tumor-bearing versus tumor-free hemispheres; ^#<i>p</i><0.05, CsA (10 mg/kg, 8th) versus PBS-treated, tumor-bearing mice. C. MMP-2 activity in proteins extracts from the brains of naïve (N1–5) and tumor-bearing mice (T1–5) determined by gel zymography. Active MMP-2 detected as a prominent band at 62 kDa. D. Quantification of MMP-2 activity using the cleavage of fluorescent DQ-gelatin substrate; means ± SEM of 4–6 mice; ^**<i>p</i><0.01, tumor-bearing versus naïve brain extracts; ^###<i>p</i><0.001, ^#<i>p</i><0.05, CsA- versus PBS-treated tumor-bearing mice.</p

Accumulation and activation of microglia/macrophages in experimental glioma.

<p>A. Representative confocal images of brain sections 15 days after implantation of pEGFP-N1 GL261 cells into the striatum of C57BL/6 mice. Note the infiltration and morphological transformation of glioma-infiltrating Iba1⁺ cells. Scale bar: left image – 1000 µm, right image – 20 µm. B. Contralateral and ipsilateral hemisphere from tumor-bearing brain 15 days after injection of pEGFP-N1 GL261 cells. Images showed merged Iba1 and EGFP fluorescence. Scale bar = 750 µm. C. Microglia/macrophages were separated using a magnetic-bead-conjugated anti-CD11b antibody and stained with CD45 PerCP-Cy5.5 and CD11b PE prior to FACS acquisition. Propidium iodide staining was performed to eliminate necrotic/apoptotic cells (Gate R3, R4) and viable cells were gated (Gate R1; <b>B1</b>, Gate R2; <b>B2</b>). D. Efficiency of CD11b-positive cells separation in the negative fraction (CD11b-negative cells) from each sample was controlled. E. Representative dot plots for microglia (Gate R4, CD11b⁺/CD45^low) and macrophages (Gate R5, CD11b⁺/CD45^high) from tumor-bearing hemispheres. F. Kinetics of microglia/macrophage influx into tumor tissue. CD11b⁺ cells separated from the brains of naïve, sham operated and tumor-bearing mice at day 3, 8 or 15 after implantation (n = 4/group) were sorted according to CD45 expression. Each bar represents the mean ± SEM; ^***<i>p</i><0.001, ^*<i>p</i><0.05 tumor-bearing mice at 8th day versus naïve mice; ^##<i>p</i><0.01 tumor-bearing mice at day 15 versus day 8.</p