Quercetin prevents methylmercury-induced mitochondrial dysfunction in the cerebral cortex of mice.

Methylmercury (MeHg) exposure can cause nerve damage and mitochondrial dysfunction. Mitochondrial dysfunction is mainly mediated by mitochondrial biogenesis and mitochondrial dynamics disorders. Quercetin (QE) plays an important role in activating silencing information regulator 2 related enzyme 1 (SIRT1), and SIRT1 activates peroxisome-proliferator-activated receptor-γ co-activator 1α (PGC-1α), which can regulate mitochondrial biogenesis and mitochondrial dynamics. The main purpose of this study was to explore the alleviating effects of QE on MeHg-induced nerve damage and mitochondrial dysfunction. The results showed that QE could reduce the excessive production of reactive oxygen species (ROS) and the loss of membrane potential induced by MeHg. Meanwhile, QE activated SIRT1 activity and SIRT1/PGC-1α signaling pathway, improved mitochondrial biogenesis and fusion and reduced mitochondrial fission. In summary, we hypothesized that QE prevents MeHg-induced mitochondrial dysfunction by activating SIRT1/PGC-1α signaling pathway.

Bioactive solanidane steroidal alkaloids from Solanum lyratum.

Six previously unreported solanidane steroidal alkaloids, namely lyrasolanosides A-F, were isolated from Solanum lyratum. In addition, five known steroidal alkaloids were also identified. The structures of these compounds were determined through the use of NMR, HRESIMS,UV, IR and ECD analysis. To assess their bioactivities, the cytotoxic effects of the six previously unreported compounds were evaluated on A549 cells. The results revealed that lyrasolanoside B (2) exhibited the highest potency among them. Lyrasolanoside B (2) exhibited significant inhibition of cell migration, invasion, and adhesion dramatically. Mechanistically, it was found to suppress the activity of JAK2/STAT3 signaling pathway by downregulating the expression of phosphorylated JAK2/STAT3 in an exosome-dependent manner. In addition, lyrasolanoside B (2) was found to significantly upregulate the expression of E-cadherin and downregulate the expression of N-cadherin and vimentin. These findings indicate that lyrasolanoside B (2) inhibits the metastasis of A549 cells by suppressing exosome-mediated EMT. These findings suggest that lyrasolanoside B (2) may inhibit the metastasis of lung cancer by regulating A549-derived exosomes.

N-acetylcysteine protects against neurodevelopmental injuries induced by methylmercury exposure during pregnancy and lactation.

As an extremely dangerous environmental contaminant, methylmercury (MeHg) results in detrimental health effects in human brain nervous system, one of its main targets. However, as a developmental toxicant, the brain of offspring is vulnerable to MeHg during pregnancy and lactation exposure. Unfortunately, mechanisms of neurodevelopmental injuries induced by MeHg have not been fully elucidated. N-acetylcysteine (NAC) has been used for several decades as an antioxidant to antagonize oxidative stress. However, the molecular mechanisms of NAC alleviating MeHg-induced neurodevelopmental toxicity are not clear. Here, for evaluation of the dose-dependent effects of MeHg exposure on neurodevelopmental injuries of offspring, and the possible protective effects of NAC, the pregnant female mice were exposed to MeHg (4, 8, 12 mg/L, respectively) and NAC (50, 100, 150 mg/kg, respectively) from gestational day 1 (GD1) to postnatal day 21 (PND21). Our results indicated that administering MeHg caused behavioral impairment and neuronal injuries in the cerebral cortex of newborn mice. MeHg dose-dependently caused reactive oxygen species (ROS) overproduction and oxidative stress aggravation, together with expression of Nrf2, HO-1, Notch1, and p21 up-regulation, and CDK2 inhibition. NAC treatment dose-dependently antagonized MeHg-induced oxidative stress that may contribute to alleviating neurobehavioral and neurodevelopmental impairments. These results give insight into that NAC can protect against MeHg-induced neurodevelopmental toxicity by its antioxidation capacity.

Emodin suppresses adipogenesis of bone marrow derived mesenchymal stem cells from aplastic anemia via increasing TRIB3 expression.

BACKGROUND: Increasing evidence indicate that enhanced adipogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs) could contribute to the adiposity alteration in marrow microenvironment of aplastic anemia (AA). Identifying small molecule drugs with role in inhibiting adipogenesis of BM-MSCs may represent a novel direction in AA therapy by improving BM-MSCs mediated marrow microenvironment. METHODS: For the purpose, we isolated AA BM-MSCs through whole bone marrow cell culture, evaluated a series of small molecule drugs using the in vitro adipogenic differentiation model of BM-MSCs, and finally focused on emodin, a natural anthraquinone derivative. Subsequently, we systematically investigated the molecular mechanism of emodin in attenuating adipogenic process by means of microarray profiling, bioinformatics analysis and lentivirus-mediated functional studies and rescue assay. RESULTS: We found that emodin presented significantly suppressive effect on the in vitro adipogenic differentiation of AA BM-MSCs. Further mechanistic investigation revealed that emodin could increase the expression of Tribbles homolog 3 (TRIB3) which exhibited remarkably decreased expression in AA BM-MSCs compared with the normal counterparts and was subsequently demonstrated as a negative regulator in adipogenesis of AA BM-MSCs. Besides, TRIB3 depletion alleviated the suppressive effect of emodin on the adipogenic differentiation of AA BM-MSCs. CONCLUSION: Our findings propose that emodin mediated TRIB3 up-regulation alleviates the adipogenic capacity of AA BM-MSCs, and emodin could serve as a potential therapeutic regimen for AA therapy.

Study of ATF4/CHOP axis-mediated mitochondrial unfolded protein response in neuronal apoptosis induced by methylmercury.

Methylmercury (MeHg) is a widely distributed environmental pollutant that can easily cross the blood-brain barrier and accumulate in the brain, thereby damaging the central nervous system. Studies have shown that MeHg-induced mitochondrial damage and apoptosis play a crucial role in its neurotoxic effects. Mitochondrial unfolded protein response (UPRmt) is indispensable to maintain mitochondrial protein homeostasis and ensure mitochondrial function, and the ATF4/CHOP axis is one of the signaling pathways to activate UPRmt. In this study, the role of the ATF4/CHOP axis-mediated UPRmt in the neurotoxicity of MeHg has been investigated by C57BL/6 mice and the HT22 cell line. We discovered that mice exposed to MeHg had abnormal neurobehavioral patterns. The pathological section showed a significant decrease in the number of neurons. MeHg also resulted in a reduction in mtDNA copy number and mitochondrial membrane potential (MMP). Additionally, the ATF4/CHOP axis and UPRmt were found to be significantly activated. Subsequently, we used siRNA to knock down ATF4 or CHOP and observed that the expression of UPRmt-related proteins and the apoptosis rate were significantly reduced. Our research showed that exposure to MeHg can over-activate the UPRmt through the ATF4/CHOP axis, leading to mitochondrial damage and ultimately inducing neuronal apoptosis.

Dual roles of UPRer and UPRmt in neurodegenerative diseases.

The unfolded protein response (UPR) is a cellular stress response mechanism induced by the accumulation of unfolded or misfolded proteins. Within the endoplasmic reticulum and mitochondria, a dynamic balance exists between protein folding mechanisms and unfolded protein levels under normal conditions. Disruption of this balance or an accumulation of unfolded proteins in these organelles can result in stress responses and UPR. The UPR restores organelle homeostasis and promotes cell survival by increasing the expression of chaperone proteins, regulating protein quality control systems, and enhancing the protein degradation pathway. However, prolonged or abnormal UPR can also have negative effects, including cell death. Therefore, many diseases, especially neurodegenerative diseases, are associated with UPR dysfunction. Neurodegenerative diseases are characterized by misfolded proteins accumulating and aggregating, and neuronal cells are particularly sensitive to misfolded proteins and are prone to degeneration. Many studies have shown that the UPR plays an important role in the pathogenesis of neurodegenerative diseases. Here, we will discuss the possible contributions of the endoplasmic reticulum unfolded protein response (UPRer) and the mitochondrial unfolded protein response (UPRmt) in the development of several neurodegenerative diseases.

[Quality analysis of Rosae Radix et Rhizoma].

Rosae Radix et Rhizoma is a herbal medicine in a variety of famous Chinese patent medicines, while the quality standard for this medicine remains to be developed due to the insufficient research on the quality of Rosae Radix et Rhizoma from different sources. Therefore, this study comprehensively analyzed the components in Rosae Radix et Rhizoma of different sources from the aspects of extract, component category content, identification based on thin-lay chromatography, active component content determination, and fingerprint, so as to improve the quality control. The results showed that the content of chemical components varied in the samples of different sources, while there was little difference in the chemical composition among the samples. The content of components in the roots of Rosa laevigata was higher than that in the other two species, and the content of components in the roots was higher than that in the stems. The fingerprints of triterpenoids and non-triterpenoids were established, and the content of five main triterpenoids including multiflorin, rosamultin, myrianthic acid, rosolic acid, and tormentic acid in Rosae Radix et Rhizoma was determined. The results were consistent with those of major component categories. In conclusion, the quality of Rosae Radix et Rhizoma is associated with the plant species, producing area, and medicinal parts. The method established in this study lays a foundation for improving the quality standard of Rosae Radix et Rhizoma and provides data support for the rational use of the stem.

Fast synthesis of large-area bilayer graphene film on Cu.

Bilayer graphene (BLG) is intriguing for its unique properties and potential applications in electronics, photonics, and mechanics. However, the chemical vapor deposition synthesis of large-area high-quality bilayer graphene on Cu is suffering from a low growth rate and limited bilayer coverage. Herein, we demonstrate the fast synthesis of meter-sized bilayer graphene film on commercial polycrystalline Cu foils by introducing trace CO2 during high-temperature growth. Continuous bilayer graphene with a high ratio of AB-stacking structure can be obtained within 20 min, which exhibits enhanced mechanical strength, uniform transmittance, and low sheet resistance in large area. Moreover, 96 and 100% AB-stacking structures were achieved in bilayer graphene grown on single-crystal Cu(111) foil and ultraflat single-crystal Cu(111)/sapphire substrates, respectively. The AB-stacking bilayer graphene exhibits tunable bandgap and performs well in photodetection. This work provides important insights into the growth mechanism and the mass production of large-area high-quality BLG on Cu.

Apicidin confers promising therapeutic effect on acute myeloid leukemia cells via increasing QPCT expression.

Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy characterized by abnormal cell proliferation, apoptosis repression and myeloid differentiation blockade of hematopoietic stem/progenitor cells. Developing and identifying novel therapeutic agents to reverse the pathological processes of AML are of great significance. Here in this study, we found that a fungus-derived histone deacetylase inhibitor, Apicidin, presents promising therapeutic effect on AML by inhibiting cell proliferation, facilitating apoptosis and inducing myeloid differentiation of AML cells. Mechanistic investigation revealed that QPCT is identified as a potential downstream target of Apicidin, which exhibits significantly decreased expression in AML samples compared with the normal controls and is remarkably up-regulated in AML cells upon Apicidin management. Functional study and rescue assay demonstrated that QPCT depletion further promotes cell proliferation, inhibits apoptosis and impairs myeloid differentiation of AML cells, alleviating the anti-leukemic effect of Apicidin on AML. Our findings not only provide novel therapeutic target for AML, but also lay theoretical and experimental foundation for the clinical application of Apicidin in AML patients.

[Regulatory effect of eight Chinese herbal medicines on glucose and lipid metabolism and their potential active components based on HCBP6 target].

With the improvement of living standards and changes in working style, the prevalence of abnormal glucose and lipid metabolism in humans is increasing in modern society. Clinically, the related indicators are often improved by changing the lifestyle and/or taking hypoglycemic and lipid-lowering drugs, but there are no therapeutic drugs for disorders of glucose and lipid metabolism at present. Hepatitis C virus core protein binding protein 6(HCBP6) is a newly discovered target that can regulate triglyceride and cholesterol content according to level oscillations in the body, thereby regulating abnormal glucose and lipid metabolism. Relevant studies have shown that ginsenoside Rh_2 can significantly up-regulate the expression of HCBP6, but there are few studies on the effect of Chinese herbal medicines on HCBP6. Moreover, the three-dimensional structural information of HCBP6 has not been determined and the discovery of potential active components acting on HCBP6 is not rapidly advanced. Therefore, the total saponins of eight Chinese herbal medicines commonly used to regulate abnormal glucose and lipid metabolism were selected as the research objects to observe their effect on the expression of HCBP6. Then, the three-dimensional structure of HCBP6 was predicted, followed by molecular docking with saponins in eight Chinese herbal medicines to quickly find potential active components. The results showed that all total saponins tended to up-regulate HCBP6 mRNA and protein expression, where gypenosides showed the optimum effect on up-regulating HCBP6 mRNA and ginsenosides showed the optimum effect on up-regulating HCBP6 protein expression. Reliable protein structures were obtained after the prediction of protein structures using the Robetta website and the evaluation of the predicted structures by SAVES. The saponins from the website and literature were also collected and docked with the predicted protein, and the saponin components were found to have good binding activity to the HCBP6 protein. The results of the study are expected to provide ideas and methods for the discovery of new drugs from Chinese herbal medicines to regulate glucose and lipid metabolism.

Chidamide suppresses adipogenic differentiation of bone marrow derived mesenchymal stem cells via increasing REEP2 expression.

Increased propensity of bone marrow-derived mesenchymal stem cells (BM-MSCs) toward adipogenic differentiation at the expense of osteogenesis has been implicated in obesity, diabetes, and age-related osteoporosis as well as various hematopoietic disorders. Defining small molecules with role in rectifying the adipo-osteogenic differentiation imbalance is of great significance. Here, we unexpectedly found that Chidamide, a selective histone deacetylases inhibitor, exhibited remarkably suppressive effect on the in vitro induced adipogenic differentiation of BM-MSCs. Multifaceted alterations in the spectrum of gene expression were observed in Chidamide-managed BM-MSCs during adipogenic induction. Finally, we focused on REEP2, which presented decreased expression in BM-MSCs-mediated adipogenesis and was restored by Chidamide treatment. REEP2 was subsequently demonstrated as a negative regulator of adipogenic differentiation of BM-MSCs and mediated the suppressive effect of Chidamide on adipocyte development. Our findings provide the theoretical and experimental foundation for the clinical application of Chidamide for disorders associated with excessive marrow adipocytes.

Ferroptosis and Neurodegenerative Diseases: Insights into the Regulatory Roles of SLC7A11.

Programed cell death plays a key role in promoting human development and maintaining homeostasis. Ferroptosis is a recently identified pattern of programmed cell death that is closely associated with the onset and progression of neurodegenerative diseases. Ferroptosis is mainly caused by the intracellular accumulation of iron-dependent lipid peroxides. The cysteine/glutamate antibody Solute carrier family 7 member 11 (SLC7A11, also known as xCT) functions to import cysteine for glutathione biosynthesis and antioxidant defense. SLC7A11 has a significant impact on ferroptosis, and inhibition of SLC7A11 expression promotes ferroptosis. Moreover, SLC7A11 is also closely associated with neurodegenerative diseases. In this paper, we summarize the relationship between ferroptosis and neurodegenerative diseases and the role of SLC7A11 during this process. The various regulatory mechanisms of SLC7A11 are also discussed. In conclusion, we are looking forward to a theoretical basis for further understanding the occurrence and development of ferroptosis in SLC7A11 and neurodegenerative diseases, and to seek new clues for the treatment of neurodegenerative diseases.

Cathodoluminescence Spectroscopy in Graded InxGa1-xN.

InGaN materials are widely used in optoelectronic devices due to their excellent optical properties. Since the emission wavelength of the full-composition-graded InxGa1-xN films perfectly matches the solar spectrum, providing a full-spectrum response, this makes them suitable for the manufacturing of high-efficiency optoelectronic devices. It is extremely important to study the optical properties of materials, but there are very few studies of the luminescence of full-composition-graded InxGa1-xN ternary alloy. In this work, the optical properties of full-composition-graded InxGa1-xN films are studied by cathodoluminescence (CL). The CL spectra with multiple luminescence peaks in the range of 365-1000 nm were acquired in the cross-sectional and plan-view directions. The CL spectroscopy studies were carried out inside and outside of microplates formed under the indium droplets on the InGaN surface, which found that the intensity of the light emission peaks inside and outside of microplates differed significantly. Additionally, the paired defects structure is studied by using the spectroscopic method. A detailed CL spectroscopy study paves the way for the growth and device optimization of high-quality, full-composition-graded InxGa1-xN ternary alloy materials.

The Beneficial Role of Sirtuin 1 in Preventive or Therapeutic Options of Neurodegenerative Diseases.

Sirtuin 1 (SIRT1) is an NAD+ dependent deacetylase that modify the gene expression through histone deacetylation. SIRT1 plays a crucial role in regulating a wide range of physiological processes by adjustment multiple mechanisms through the deacetylation of multiple substrates. Neurodegenerative diseases are a series of chronic diseases characterized by dysfunction and loss of neurons. Its basic pathogenesis is filamentous tangles and amyloid deposits, such as Amyloid-ß (Aß), tau protein, α-synuclein, including Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). This summarizes introduces the structure and function of SIRT1, and then analyzes the protective effects of SIRT1 on neurological diseases by regulating circadian rhythm, aging, oxidative stress, mitochondrial dysfunction and neuroinflammation related pathways.

Exploring the molecular mechanisms underlie the endoplasmic reticulum stress-mediated methylmercury-induced neuronal developmental damage.

Methylmercury (MeHg) is a ubiquitous environmental pollutant, which can cross the placenta and blood brain barrier, thus affecting fetal growth and development. Although previous studies have demonstrated that MeHg induces endoplasmic reticulum (ER) stress in rat cerebral cortex and primary neurons, the role of ER stress in MeHg-induced neurodevelopmental toxicity remains unclear. Here, we used ICR pregnant mice and hippocampal neurons cells (HT22 cells) to investigate the molecular mechanism by which MeHg exposure during pregnancy affects neurodevelopment. We found that prenatal MeHg exposure caused developmental delay in offspring, accompanied with ER stress, cell apoptosis, cell cycle arrest and abnormal DNA methylation. Then, we used ER stress specific inhibitor 4-PBA and CHOP siRNA to investigate the role of ER stress on HT22 cells damage caused by MeHg. The results showed that 4-PBA pretreatment restored MeHg-induced axonal shortening and alleviated apoptosis, cell cycle arrest and DNA methylation. At the same time, the activation of CHOP/c-Jun/GADD45A signaling pathway was inhibited, and the interaction between CHOP and c-Jun was weakened. In addition, CHOP siRNA reduced the expression of c-Jun and GADD45A, and relieved DNA methylation levels to some extent. In summary, our study suggested that ER stress induced by MeHg mediated cell apoptosis and cell cycle arrest, and may affect DNA methylation through activation of CHOP/c-Jun/GADD45A signaling pathway, thus leading to neuronal damage.

Simple Fabrication of Polyvinylidene Fluoride/Graphene Composite Membrane with Good Lipophilicity for Oil Treatment.

Graphene (GE) is an emerging type of two-dimensional functional nanoparticle with a tunable passageway for oil molecules. Herein, polyvinylidene fluoride (PVDF)/GE composite membranes with controllable pore structure were fabricated with a simple non-solvent-induced phase separation method. The change of crystallinity and crystal structure (α, ß, γ, etc.) generated is due to the addition of GE, which benefits the design of a suitable pore structure for oil channels. Meanwhile, the hydrophobicity and thermal stability of the composite membrane were obviously enhanced. With 3 wt % GE, the contact angle was 124.6°, which was increased greatly compared to that of the GE-0 sample. Moreover, the rate of the phase transition process was affected by the concentration of casting solution, temperature, and composition of the coagulation bath. For example, the composite membrane showed better oil-water separation properties when the coagulation bath was dioctyl phthalate. In particular, the oil flux and separation efficiencies were up to 2484.08 L/m2·h and 99.24%, respectively. Consequently, PVDF/GE composite membranes with excellent lipophilicity may have good prospects for oily wastewater treatment.

Enhancing conversion of polysulfides via porous carbon nanofiber interlayer with dual-active sites for lithium-sulfur batteries.

Lithium-sulfur (Li-S) batteries are promising candidates for next-generation energy storage. However, the notorious lithium polysulfides (LiPSs) shuttle effect and torpid redox kinetics hinder their practical application. Enhancing phase conversion efficiency and limiting the dissolution of LiPSs are critical for stabilizing Li-S batteries. Herein, sulfiphilic defective TiO2 nanoparticles (D-TiO2) were integrated into the lithiophilic N-doped porous carbon nanofiber membrane (D-TiO2@NPCNF) to construct interlayer for catalyzing the conversion of LiPSs. The D-TiO2@NPCNF provides hierarchical porous structure and large specific surface area, and the formed 3D conductive network accelerates the transport of electrons and ions. The dual-active sites (N and D-TiO2) enhance the interface conversion and chemisorption ability of LiPSs via forming "Li-N and Ti-S" bonds. Due to the structural advantage of the D-TiO2@NPCNF, the Li-S batteries exhibit excellent cycling stability (only 0.049% decay per cycle in 800cycles at 1.0C) and impressive specific capacity (608 mAh g-1 at 3.0C). This work is expected to deepen the comprehension of complex interphase conversion processes of LiPSs and provide novel ideas for the design of new interlayer materials.

Facial fabrication of few-layer functionalized graphene with sole functional group through Diels-Alder reaction by ball milling.

The widespread use of graphene as a next-generation material in various applications requires developing an environmentally friendly and efficient method for fabricating functionalized graphene. Chemically, graphene can be used as an electron donor or attractor. Here, graphite was successfully exfoliated, and an in situ Diels-Alder reaction (D-A) was carried out to fabricate functionalized graphene with sole functional groups via mechanochemical ball milling. The reactivities of graphene acting as a diene or a dienophile were investigated. Few-layer (≤2 layers) graphene specimens were obtained by wet ball milling, heating in a nitrogen atmosphere, and solvent ultrasonic treatment. The ball-milling method was more effective than heating in a nitrogen atmosphere, and the [2 + 4] D-A of graphene was more dominant than the [4 + 2] D-A in the ball-milling process. The surface tension of functionalized graphene decreased, which provided a theoretical basis for the dispersion and exfoliation of graphite in a suitable solvent. Functionalized graphene still had a high electrical conductivity, which has far-reaching significance for functionalized graphene to be applied in electronic semiconductors and related applications. Meanwhile, functionalized graphene was applied to polymer composite fibers, the tensile strength and the Young's modulus could reach 780 MPa and 19 GPa. The volume resistivity was two orders of magnitude lower than that of pure fiber. Thus, the use of ball milling to efficiently exfoliate and in situ functionalize graphite will help to develop a strategy that can be widely used to manufacture nanomaterials for various application fields.

Combination of low-dose rituximab, bortezomib and dexamethasone for the treatment of autoimmune hemolytic anemia.

ABSTRACT: Autoimmune hemolytic anemia (AIHA) therapy may be associated with severe complications such as diabetes, hypertension, obesity, osteoporosis, peptic ulcers, infection, and some other diseases. To reduce those effects, we used low-dose rituximab, bortezomib and dexamethasone (LowR-BD regimen) to treat AIHA. The purpose of this study was to evaluate the efficacy and safety of this regimen.Seven patients with warm AIHA (wAIHA) admitted from March 2020 to October 2020 were treated with LowR-BD regimen: Rituximab 100 mg by intravenous infusion on day 1 combined with bortezomib 1.3 mg/m2 by subcutaneous injection on day 2 plus dexamethasone 20 mg by intravenous infusion on days 2, 3. Clinical efficacy and safety were assessed at the regular reexamination of relevant indicators and follow-up.After 4 cycles of the LowR-BD regimen, the overall response rate (ORR) was 85.71% with a complete response (CR) of 28.57% and a partial response (PR) of 57.14%. After a median follow-up of 12 (range 7-13) months, 5 patients achieved CR and 2 patients had PR status, including 1 patient who did not respond to LowR-BD treatment and reached CR after using methylprednisolone combined with cyclophosphamide. One patient relapsed and achieved PR after retreatment of 2 cycles LowR-BD regimen. The patients tolerated the treatment well and did not complain of apparently adverse reactions except a patient with Sjogren's syndrome and bronchiectasis who developed a severe infection during treatment.Low-dose rituximab combined with bortezomib and dexamethasone is effective and relatively safe in patients with wAIHA.