Immune and nonimmune mechanisms mediate the mental stress-induced tumor growth in a xenograft model of breast cancer

Excess mental stress may harm health, and even accelerate cancer initiation and progression. One fourth of breast cancer patients suffer mental stress including anxiety, sadness, or depression, which negatively affect prognosis and survival. However, the regulatory mechanism is yet to be determined. Herein, we applied unpredictable stress stimuli to the breast tumor-bearing mice to establish a xenograft model of breast cancer suffering mental stress, followed by behavioral tests, tumor growth tracking, immune analysis, miRNA screening, and tumor cell proliferation analysis as well. As a result, increased stress hormone levels in serum, decreased percentage of T and NK cells in both blood and tumor samples and accelerated tumor growth in vivo were observed in the mice exposed to mental stress. Promoted cell proliferation was observed in both primary tumor cells derived from the stressed mice and 4T1 breast cancer cells treated with stress hormone corticosterone. In addition, a subset of miRNAs including miR-326, 346, 493, 595, 615, and 665 were identified through a miRNA screening with downregulation in tumors of the stressed mice. CCND1 was identified as a common target gene of miR-346 and miR-493, the top two most significantly downregulated miRNAs by stress exposure. The stress-miRNA-CCND1 signaling regulation of the tumor cell proliferation was further validated in 4T1 cells treated with corticosterone in vitro. GO terms and KEGG pathways analyses on the target genes of miR-346 and miR-493 revealed their involvement in the regulation of human cancer and neuron system, indicating the importance of non-coding genome in mediating the mental stress-induced cancer regulation. In conclusion, this study not only explored immune and nonimmune mechanisms through which mental stress exposure contributes to tumor growth in breast cancer, but also suggested a new therapeutic strategy for cancer patients suffering mental stress.Subject terms: Breast cancer, Disease model, miRNAs     

Tuning Surface Rock-Salt Layer as Effective O Capture for Enhanced Structure Durability of LiCoO2 at 4.65 V

Recently, the rock-salt (RS) phases are utilized to enhance the surface stability of LiCoO₂ (LCO), however, the optimization mechanism still remains vague. Herein, the structure stability of LCO is successfully enhanced via constructing a tough surface RS layer (≈5 nm), namely, the RS-LCO. This surface RS layer plays a significant role on capturing the migrated lattice O ions upon charging, leading to the progressive phase transition from an inert RS phase to an ionic conductive spinel phase in the surface, and suppresses the bulk H1-3 separation beyond 4.6 V. As a result, not only the oxygen redox induced side reactions are greatly reduced, but also the Li⁺-ion's transport is significantly promoted. The RS-LCO/Li cells show a remarkable cycle stability with 89.7% capacity retention after 1000 cycles in 3–4.6 V at current of 1 C (1 C = 200 mA g⁻¹), and 81.2% capacity retention after 400 cycles in 3–4.65 V at 1 C. Besides, the RS-LCO/graphite cells show nearly no capacity decay in 600 cycles in 3–4.55 V at 1 C. This work provides a new insight to understand the role of surface RS phase layer on developing the advanced LCO.     

Achieving a Quasi-Solid-State Conversion of Polysulfides via Building High Efficiency Heterostructure for Room Temperature Na–S Batteries

The practical application of room temperature sodium–sulfur (RT Na–S) batteries are prevented by the sulfur insulation, the severe shuttling effect of high-order sodium polysulfides (Na₂S_n, 4 ≤ n ≤ 8), and the sluggish reaction kinetics. Therefore, designing an ideal host material to suppress the polysulfides shuttle process and accelerate the redox reactions of soluble NaPSs to Na₂S₂/Na₂S is of paramount importance for RT Na–S batteries. Here, a quasi-solid-state transformation of NaPSs is realized by building high efficiency MoC-W₂C heterostructure in freestanding multichannel carbon nanofibers via electrospinning and calcination methods (MoC-W₂C-MCNFs). The multichannel carbon nanofibers are interlinked micro-mesoporous structures that can accommodate volume change of electrode materials and confine the entire redox process of NaPSs (restraining the polysulfides shuttle process). Meanwhile, the MoC-W₂C heterostructure with abundant heterointerfaces can facilitate electron/ion transport and accelerate conversion of NaPSs. Consequently, the S/MoC-W₂C-MCNFs cathode delivers a high capacity of 640 mAh g⁻¹ after 500 cycles at 0.2 A g⁻¹ and an excellent reversible performance of 200 mAh g⁻¹ after ultralong 3500 cycles at 4 A g⁻¹. What's more, the heterostructure catalytic mechanism (a quasi-solid-state transformation) is proposed and confirmed in carbonate electrolyte by combining experimentally and theoretically.     

The long rod-shaped Sr2MgSi2O7:Eu2+,Dy3+ with ultrahigh afterglow performance

The afterglow properties of long afterglow luminescent materials are greatly affected by their defects, which are distributed on the grain surface. Increasing the exposed surface area is an important method to improve the afterglow performance. In this research, long rod-shaped long afterglow materials Sr₂MgSi₂O₇:Eu²⁺,Dy³⁺ were prepared using the hydrothermal-coprecipitation method. When the reaction time reached 96 h, the length of the afterglow materials could grow to 2 mm, and the sintering temperature was just 1150°C. The emission spectra of all obtained samples upon excitation at 397 nm had a maximum of 465 nm, which belonged to the representative transition of Eu²⁺. The initial brightness was 1.35 cd/m². The afterglow time could reach 19 h, giving a good afterglow performance. The research on this kind of material has essential significance in the exploration of luminescence mechanisms and their applications.     

Rab-H_1b is essential for trafficking of cellulose synthase and for hypocotyl growth in Arabidopsis thaliana

Cell-wall deposition of cellulose microfibrils is essential for plant growth and development. In plant cells,cellulose synthesis is accomplished by cellulose synthase complexes located in the plasma membrane. Trafficking of the complex between endomembrane compartments and the plasma membrane is vital for cellulose biosynthesis;however, the mechanism for this process is not well understood. We here report that, in Arabidopsis thaliana,Rab-H_1b, a Golgi-localized small GTPase, participates in the trafficking of CELLULOSE SYNTHASE 6(CESA6) to the plasma membrane. Loss of Rab-H_1b function resulted in altered distribution and motility of CESA6 in the plasma membrane and reduced cellulose content. Seedlings with this defect exhibited short, fragile etiolated hypocotyls.Exocytosis of CESA6 was impaired in rab-h1 b cells, and endocytosis in mutant cells was significantly reduced as well. We further observed accumulation of vesicles around an abnormal Golgi apparatus having an increased number of cisternae in rab-h1 b cells, suggesting a defect in cisternal homeostasis caused by Rab-H_1b loss function. Our findings link Rab GTPases to cellulose biosynthesis, during hypocotyl growth, and suggest Rab-H_1b is crucial for modulating the trafficking of cellulose synthase complexes between endomembrane compartments and the plasma membrane and for maintaining Golgi organization and morphology.e