Protective effect of ginsenoside Rh2 against Toxoplasma gondii infection-induced neuronal injury through binding TgCDPK1 and NLRP3 to inhibit microglial NLRP3 inflammasome signaling pathway.

BACKGROUND: Toxoplasma gondii (T. gondii) is a neurotropic obligate intracellular parasite that can activate microglial and promote neuronal apoptosis, leading to central nervous system diseases. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling complex plays a key role in inducing neuroinflammation. Our previous studies have found that ginsenoside Rh2 (GRh2) inhibits T. gondii infection-induced microglial activation and neuroinflammation by downregulating the Toll-like receptor 4/nuclear factor-kappa B signaling pathway. However, whether GRh2 reduces T. gondii infection-induced neuronal injury through actions on microglial NLRP3 inflammasome signaling has not yet been clarified. METHODS: In this study, we employed T. gondii RH strain to establish in vitro and in vivo infection models in BV2 microglia cell line and BALB/c mice. Molecular docking, localized surface plasmon resonance assay, quantitative competitive-PCR, ELISA, western blotting, flow cytometric analysis, and immunofluorescence were performed. RESULTS: Our results showed that GRh2 alleviated neuropathological damage and neuronal apoptosis in cortical tissue of T. gondii-infected mice. GRh2 and CY-09 (an inhibitor of NLRP3) exhibited potent anti-T. gondii effects through binding T. gondii calcium-dependent protein kinase 1 (TgCDPK1). GRh2 decreased Iba-1 (a specific microglial marker) and NLRP3 inflammasome signaling pathway-related protein expression by binding NLRP3. Co-culture of microglia/primary cortical neurons revealed that T. gondii-induced microglial activation caused neuronal apoptosis, but GRh2 reduced this effect, consistent with the effects of CY-09. CONCLUSION: Taken together, our results show that GRh2 has a protective effect against T. gondii infection-induced neuronal injury by binding TgCDPK1 and NLRP3 to inhibit NLRP3 inflammasome signaling pathway in microglia.

Spatial Pattern of Endophytic Fungi and the Symbiotic Germination of Tulasnella Fungi from Wild Cymbidium goeringii (Orchidaceae) in China.

The endophytic microbiome in orchid plants is rich and diverse; however, few studies have analyzed the endophytic microbiome of Cymbidium plants in different tissues and soils. This study implemented the Illumina Miseq technology to investigate the diversity of endophytic fungi in different tissues of wild Cymbidium goeringii. The results demonstrated that different tissue samples harbor a rich fungal endophytic community, and those fungi could be classified into 4 phyla, at least 145 families, and 185 genera. The endophytic fungal community diversity differed among the orchid tissues and soils, and some fungal taxa were clearly concentrated in certain orchid tissues, with more operational taxonomic units (OTUs) being detected. Investigation of mycorrhizal associations showed that 43 (about 3.8%) of the total 1137 OTUs could be assigned as Orchidaceae mycorrhizal fungi (OMF), while about 96.2% the OTUs were non-mycorrhizal fungi. Among the OMFs, OTUs of the ectomycorrhizal fungi Russulaceae and Thelephoraceae families were the most abundant, with different richness in the soil, followed by Tulasnellaceae and Ceratobasidiaceae, which were dominant in the root communities of C. goeringii. In the seeds, the absolutely dominant family was Nectriaceae, and the common OMFs Ceratobasidiaceae (five OTUs) and Tulasnellaceae (one OTU) were also detected in the seeds. Two Tulasnella spp. isolates from the roots of wild C. goeringii could effectively promote seed germination and rhizome formation of wild C. goeringii, and these strains might be particularly important in the practice of conservation for many endangered C. goeringii in China.

Ginsenoside Rh2 reduces depression in offspring of mice with maternal toxoplasma infection during pregnancy by inhibiting microglial activation via the HMGB1/TLR4/NF-κB signaling pathway.

BACKGROUND: Maternal Toxoplasma gondii (T. gondii) infection during pregnancy has been associated with various mental illnesses in the offspring. Ginsenoside Rh2 (GRh2) is a major bioactive compound obtained from ginseng that has an anti-T. gondii effect and attenuates microglial activation through toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway. GRh2 also alleviated tumor-associated or lipopolysaccharide-induced depression. However, the effects and potential mechanisms of GRh2 on depression-like behavior in mouse offspring caused by maternal T. gondii infection during pregnancy have not been investigated. METHODS: We examined GRh2 effects on the depression-like behavior in mouse offspring, caused by maternal T. gondii infection during pregnancy, by measuring depression-like behaviors and assaying parameters at the neuronal and molecular level. RESULTS: We showed that GRh2 significantly improved behavioral measures: sucrose consumption, forced swim time and tail suspended immobility time of their offspring. These corresponded with increased tissue concentrations of 5-hydroxytryptamine and dopamine, and attenuated indoleamine 2,3-dioxygenase or enhanced tyrosine hydroxylase expression in the prefrontal cortex. GRh2 ameliorated neuronal damage in the prefrontal cortex. Molecular docking results revealed that GRh2 binds strongly to both TLR4 and high mobility group box 1 (HMGB1). CONCLUSION: This study demonstrated that GRh2 ameliorated the depression-like behavior in mouse offspring of maternal T. gondii infection during pregnancy by attenuating the excessive activation of microglia and neuroinflammation through the HMGB1/TLR4/NF-κB signaling pathway. It suggests that GRh2 could be considered a potential therapy in preventing and treating psychiatric disorders in the offspring mice of mothers with prenatal exposure to T. gondii infection.

New role of sertraline against Toxoplasma gondii-induced depression-like behaviours in mice.

Toxoplasma gondii (T. gondii) is a neurotropic protozoan parasite, which can cause mental and behavioural disorders. The present study aimed to elucidate the effects and underlying molecular mechanisms of sertraline (SERT) on T. gondii-induced depression-like behaviours. In the present study, a mouse model and a microglial cell line (BV2 cells) model were established by infecting with the T. gondii RH strain. In in vivo and in vitro experiments, the underlying molecular mechanisms of SERT in inhibiting depression-like behaviours and cellular perturbations caused by T. gondii infection were investigated in the mouse brain and BV2 cells. The administration of SERT significantly ameliorated depression-like behaviours in T. gondii-infected mice. Furthermore, SERT inhibited T. gondii proliferation. Treatment with SERT significantly inhibited the activation of microglia and decreased levels of pro-inflammatory cytokines such as tumour necrosis factor-alpha, and interferon-gamma, by down-regulating tumour necrosis factor receptor 1/nuclear factor-kappa B signalling pathway, thereby ameliorating the depression-like behaviours induced by T. gondii infection. Our study provides insight into the underlying molecular mechanisms of the newly discovered role of SERT against T. gondii-induced depression-like behaviours.

Resveratrol modulates Toxoplasma gondii infection induced liver injury by intervening in the HMGB1/TLR4/NF-κB signaling pathway.

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite that can cause liver diseases in the host, including hepatitis and hepatomegaly. High mobility group box 1 (HMGB1) is the main inflammatory mediator causing cell injury or necrosis. HMGB1 binds to toll like receptor 4 (TLR4), then activates the nuclear factor-κB (NF-κB) signaling pathway, which promotes the release of inflammatory factors. Our previous studies showed that HMGB1 mediated TLR4/NF-κB signaling pathway plays an important role in liver injury induced by T. gondii infection. Resveratrol (RSV) is a small polyphenol, which has anti-inflammatory, anti-cancer, anti-T. gondii effect. However, the effect of RSV on liver injury caused by T. gondii infection is unclear. This study used the RH strain tachyzoites of T. gondii to infect murine liver line, NCTC-1469 cells to establish an in vitro model and acute infection of mice for the in vivo model to explore the protective effect of RSV on liver injury induced by T. gondii infection. The results showed that RSV inhibited the proliferation of T. gondii in the liver, reduced the alanine aminotransferase/aspartate aminotransferase levels and pathological liver damage. Additionally, RSV inhibited the production of tumor necrosis factor-α, inducible nitric oxide synthase and HMGB1 by interfering with the TLR4/NF-κB signaling pathway. These results indicate that RSV can protect liver injury caused by T. gondii infection by intervening in the HMGB1/TLR4/NF-κB signaling pathway. This study will provide a theoretical basis for RSV treatment of T. gondii infection induced liver injury.

Efficient Photoelectrochemical Water Oxidation on Hematite with Fluorine-Doped FeOOH and FeNiOOH as Dual Cocatalysts.

An effective cocatalyst is usually required to improve the performance of photoelectrochemical (PEC) water splitting catalysts. A fluorine-doped FeOOH (F:FeOOH) cocatalyst on a hematite photoanode was used to lower the onset potential by 140 mV and significantly improve the PEC performance. Moreover, a more effective dual cocatalytic system was prepared by subsequent loading of a FeNiOOH cocatalyst, which resulted in a further decrease of the onset potential by 270 mV. The final onset potential of the Fe2 O3 /F:FeOOH/FeNiOOH photoanode was lowered to 0.45 V versus the reversible hydrogen electrode (RHE), which is one of the lowest onset potential values ever reported for hematite photoanodes. The photocurrent also dramatically increased by a factor of approximately 3 to 0.9 mA cm-2 at 1.0 V versus RHE. Based on the structural, chemical, and electrochemical impedance spectroscopy characterization, the enhanced performance was attributed to the F:FeOOH overlayer, which reduced the surface recombination and accelerated the oxygen evolution reaction activity, and the FeNiOOH cocatalyst, which further enhanced the reaction kinetics. The facile preparation of the F:FeOOH cocatalyst and the design of the dual cocatalytic system will allow the development of high-performance hematite photoanodes.

Triboelectric Nanogenerator Driven Self-Powered Photoelectrochemical Water Splitting Based on Hematite Photoanodes.

Hematite is one of the most promising photoanodes for photoelectrochemical (PEC) solar water splitting. However, due to the low conduction band position for water reduction, an external bias is necessarily required with the consumption of extra power. In this work, a titanium modified hematite (Ti-Fe2O3) photoanode-based self-powered PEC water splitting system in tandem with a rotatory disc-shaped triboelectric nanogenerator (RD-TENG) has been developed. It is a fantastic strategy to effectively drive the hematite-based PEC water splitting by using the environmental mechanical energy through a TENG. When the rotation speed is 65 rpm (water flowing rate ∼0.61 m/s), the peak current reaches to 0.12 mA under illumination contrast to that in the dark with almost zero. As for 80 rpm, the peak currents are 0.17 and 0.33 mA in the dark or under illumination, respectively, indicating the simultaneous occurrence of electrolysis and PEC water splitting. When higher than 120 rpm, the peak current in the dark is nearly equal to that under illumination, which can be attributed to the high enough peak voltage for direct electrolysis of water. Such a self-powered PEC water splitting system provides an alternative strategy that enables to convert both solar and mechanical energies into chemical energies.

Boron-passivated surface Fe(iv) defects in hematite for highly efficient water oxidation.

Hematite is a good photocatalyst for solar water oxidation but its performance is highly limited by the strong electron-hole recombination. Surface defects as recombination centers were considered as one of the most important factors in determining the efficiency of hematite. However, the defects have never been clearly identified, which strongly limits the targeted modification. Here we report the identification of surface Fe(iv) defects in hematite by using synchrotron radiation based X-ray absorption spectroscopy. Moreover, the Fe(iv) defects can be effectively passivated by facile surface engineering with boron-termination, which can suppress the surface recombination and then significantly improve the performance. The B-passivated hematite thus shows a large cathodic shift (up to 100 mV) of the onset potential when compared to the pristine sample, and can be effectively coupled with Ti-treatment and Co-Pi co-catalyst to finally achieve a high photocurrent of 2.61 mA cm-2 at 1.23 V vs. RHE. The results may open up a new way by targeted surface engineering to effectively passivate the defects in hematite.

Liquid-Metal-Based Super-Stretchable and Structure-Designable Triboelectric Nanogenerator for Wearable Electronics.

The rapid advancement of intelligent wearable electronics imposes the emergent requirement for power sources that are deformable, compliant, and stretchable. Power sources with these characteristics are difficult and challenging to achieve. The use of liquid metals as electrodes may provide a viable strategy to produce such power sources. In this work, we propose a liquid-metal-based triboelectric nanogenerator (LM-TENG) by employing Galinstan as the electrode and silicone rubber as the triboelectric and encapsulation layer. The small Young's modulus of the liquid metal ensures the electrode remains continuously conductive under deformations, stretching to a strain as large as ∼300%. The surface oxide layer of Galinstan effectively prevents the liquid Galinstan electrode from further oxidization and permeation into silicone rubber, yielding outstanding device stability. Operating in the single-electrode mode at 3 Hz, the LM-TENG with an area of 6 × 3 cm2 produces an open-circuit voltage of 354.5 V, transferred short-circuit charge of 123.2 nC, short-circuit current of 15.6 µA, and average power density of 8.43 mW/m2, which represent outstanding performance values for TENGs. Further, the LM-TENG maintains stable performance under various deformations, such as stretching, folding, and twisting. LM-TENGs in different forms, such as bulk-shaped, bracelet-like, and textile-like, are all able to harvest mechanical energy from human walking, arm shaking, or hand patting to sustainably drive wearable electronic devices.