PERK-Mediated Cholesterol Excretion from IDH Mutant Glioma Determines Anti-Tumoral Polarization of Microglia

Isocitrate dehydrogenase (IDH) mutation, a known pathologic classifier, initiates metabolic reprogramming in glioma cells and has been linked to the reaction status of glioma-associated microglia/macrophages (GAMs). However, it remains unclear how IDH genotypes contribute to GAM phenotypes. Here, it is demonstrated that gliomas expressing mutant IDH determine M1-like polarization of GAMs, while archetypal IDH induces M2-like polarization. Intriguingly, IDH-mutant gliomas secrete excess cholesterol, resulting in cholesterol-rich, pro-inflammatory GAMs without altering their cholesterol biosynthesis, and simultaneously exhibiting low levels of tumoral cholesterol due to expression remodeling of cholesterol transport molecules, particularly upregulation of ABCA1 and downregulation of LDLR. Mechanistically, a miR-19a/LDLR axis-mediated novel post-transcriptional regulation of cholesterol uptake is identified, modulated by IDH mutation, and influencing tumor cell proliferation and invasion. IDH mutation-induced PERK activation enhances cholesterol export from glioma cells via the miR-19a/LDLR axis and ABCA1/APOE upregulation. Further, a synthetic PERK activator, CCT020312 is introduced, which markedly stimulates cholesterol efflux from IDH wild-type glioma cells, induces M1-like polarization of GAMs, and consequently suppresses glioma cell invasion. The findings reveal an essential role of the PERK/miR-19a/LDLR signaling pathway in orchestrating gliomal cholesterol transport and the subsequent phenotypes of GAMs, thereby highlighting a novel potential target pathway for glioma therapy

Study on corrosion resistance of HAZ and TMAZ in friction stir welding joint of 7075 aluminum alloy by thermal simulation

It is difficult to characterize the variation of corrosion resistance of the narrow areas in friction stir welding (FSW) joints due to the large temperature gradient. In this paper, the welding thermal simulation was performed to simulate the heat affected zone (HAZ) and thermo-mechanical affected zone (TMAZ) of the FSW 7075-T6 aluminum alloy, and the corrosion resistance and microstructure of the simulated samples were studied. Results show that the corrosion potential changes greatly under different thermal simulation temperatures. The pitting corrosion of the HAZ simulated samples presents two pitting potentials, but for the TMAZ simulated samples, two pitting potentials will gradually evolve to one pitting potential with the increase of the maximum temperature. The electrochemical impedance spectroscopy results show that the corrosion mechanism of the HAZ and TMAZ is completely inconsistent, which is related to the differences in precipitate and grain characteristics

miR-1205/DNAJB1 reverses docetaxel chemoresistance in human triple negative breast carcinoma cells via regulation of mutp53/TAp63 signaling

Chemoresistance is the major cause of therapeutic failure in human triple negative breast carcinoma (TNBC). Docetaxel (DOC), a first-line therapeutic drug in TNBC treatment, is limited for long-term use due to the development of chemoresistance. Thus, overcoming chemoresistance of DOC remains an important challenge to improve patient’s outcome of TNBC. In this study, we aimed to investigate the molecular mechanism behind DOC chemoresistance and the possible therapeutic effects of miRNAs. Utilizing qRT-PCR analysis, we discovered that miR-1205 is gradually downregulated in human triple negative breast carcinoma MDA-MB-231 and docetaxel-resistant MDA-MB-231 (MDA-MB-231/DOC) cells compared with Hs 578Bst normal human breast fibroblasts. Cell viability, cell cycle and apoptosis assays in MDA-MB-231/DOC cells indicated that miR-1205 overexpression enhances docetaxel sensitivity by reducing cell viability as well as inducing G2/M cell cycle arrest and cell apoptosis. Western blot analysis, dual-luciferase reporter assay, co-immunoprecipitation assay and chromatin immunoprecipitation assay revealed that miR-1205 overexpression disrupts the stable complex formation of DNAJB1, mutp53 and TAp63 by directly reducing DNAJB1 expression, which abates the sequestrating effect of mutp53 on TAp63, thereby leading to the enhanced DOC sensitivity in MDA-MB-231/DOC cells. Our findings demonstrate the role of the miR-1205/DNAJB1 axis in the docetaxel resistance of TNBC, which may offer a promising therapeutic approach to resolve docetaxel resistance in TNBC

An Efficient Bifunctional Electrocatalyst for a Zinc–Air Battery Derived from Fe/N/C and Bimetallic Metal–Organic Framework Composites

Efficient bifunctional electrocatalysts with desirable oxygen activities are closely related to practical applications of renewable energy systems including metal–air batteries, fuel cells, and water splitting. Here a composite material derived from a combination of bimetallic zeolitic imidazolate frameworks (denoted as BMZIFs) and Fe/N/C framework was reported as an efficient bifunctional catalyst. Although BMZIF or Fe/N/C alone exhibits undesirable oxygen reaction activity, a combination of these materials shows unprecedented ORR (half-wave potential of 0.85 V as well as comparatively superior OER activities (potential@10 mA cm^–2 of 1.64 V), outperforming not only a commercial Pt/C electrocatalyst but also most reported bifunctional electrocatalysts. We then tested its practical application in Zn–air batteries. The primary batteries exhibit a high peak power density of 235 mW cm^–2, and the batteries are able to be operated smoothly for 100 cycles at a curent density of 10 mA cm^–2. The unprecedented catalytic activity can be attritued to chemical coupling effects between Fe/N/C and BMZIF and will aid the development of highly active electrocatalysts and applications for electrochemical energy devices

APRIL Induces Cisplatin Resistance in Gastric Cancer Cells via Activation of the NF-κB Pathway

Background: A proliferation-inducing ligand (APRIL) is a tumor-necrosis factor (TNF) family member and is a novel cytokine crucial in sustaining lymphocytic leukemia B cell survival and proliferation. However, its role in gastric cancer (GC) remains unclear. In this study, we investigated the expression pattern and prognostic role of APRIL in GC. Methods: Expression of APRIL was assessed by immunohistochemistry and real-time PCR. Prognostic role of APRIL expression was evaluated. We also discovered the effect of APRIL on chemo-resistance in GC cells and the underlying mechanisms. Results: APRIL mRNA levels were significantly increased in GC tissues compared with adjacent tissues and high expression levels of APRIL in tumor cells significantly correlated with poor overall survival in patients receiving cisplatin adjuvant treatment. Overexpression of APRIL in AGS cells significantly attenuated the therapeutic efficacy of cisplatin in vitro and in vivo. In contrast, silence of APRIL in SGC7901 cells enhanced cisplatin-induced tumor suppression. Our data further revealed that the canonical NF-κB pathway was involved in APRIL-mediated chemo-resistance. In addition, expression of APRIL was regulated by miR-145 in GC cells. Conclusion: APRIL is a novel clinical chemo-resistance biomarker for gastric cancer and might be a promising therapeutic target for GC patients

Unprecedented Activity of Bifunctional Electrocatalyst for High Power Density Aqueous Zinc–Air Batteries

The development of nonprecious metal catalysts with desirable bifunctional activities to supersede noble metal catalysts is of vital importance for high performance aqueous zinc–air batteries. Here, an unprecedented activity of bifunctional electrocatalyst is reported by in situ growth of nitrogen-enriched carbon nanotubes with transition metal composite. The resultant catalyst delivers surprisingly high OER (potential@10 mA cm^–2 of 1.58 V) and ORR (onset potential of 0.97 V, half-wave potential of 0.86 V) performance. The overall oxygen electrode activity (overvoltage between ORR and OER) of the catalyst is as low as 0.72 V. In aqueous Zn–air battery tests, primary batteries demonstrate high maximum power density and two-electrode rechargeable batteries also exhibit good cycle performance. The unprecedented electrocatalyst opens up new avenues for developing highly active nitrogen-doped carbon nanotube-supported electrocatalysts and offers prospects for the next generation of fuel cells, metal–air batteries, and photocatalysis applications