IL-33 Orchestrated the Interaction and Immunoregulatory Functions of Alternatively Activated Macrophages and Regulatory T Cells In Vitro.

Our group has previously demonstrated elevated serum-soluble ST2 in patients with active systemic lupus erythematosus, suggesting a role of IL-33 in the underlying pathogenesis. However, inconsistent results have been reported on the effect of exogenous IL-33 on murine lupus activity, which may be mediated by concerted actions of various immune cells in vivo. This study aimed to examine the function of IL-33 on macrophage polarization and regulatory T cells (Treg) and their interactive effects in the lupus setting by in vitro coculture experiments of macrophages and T cells that were performed in the presence or absence of IL-33-containing medium. Compared to IL-4-polarized bone marrow-derived macrophages (BMDM) from MRL/MpJ mice, adding IL-33 enhanced mRNA expression of markers of alternatively activated macrophages, including CD206 and Arg1. IL-33 and IL-4 copolarized BMDM produced higher TGF-ß but not IL-6 upon inflammatory challenge. These BMDM induced an increase in the Foxp3+CD25+ Treg population in cocultured allogeneic T cells from MRL/MpJ and predisease MRL/lpr mice. These copolarized BMDM also showed an enhanced suppressive effect on T cell proliferation with reduced IFN-γ and IL-17 release but increased TGF-ß production. In the presence of TGF-ß and IL-2, IL-33 also directly promoted inducible Treg that expressed a high level of CD25 and more sustained Foxp3. Unpolarized BMDM cocultured with these Treg displayed higher phagocytosis. In conclusion, TGF-ß was identified as a key cytokine produced by IL-4 and IL-33 copolarized alternatively activated macrophages and the induced Treg, which may contribute to a positive feedback loop potentiating the immunoregulatory functions of IL-33.

Characterization of acetolactate decarboxylase of Streptococcus thermophilus and its stereoselectivity in decarboxylation of α-hydroxy-ß-ketoacids.

Acetolactate decarboxylase (ALDC) is a well-characterized catabolic enzyme catalyzes the decarboxylation of (±)-acetolactate to produce a single product, (R)-acetoin. It can also convert other racemic α-hydroxy-ß-ketoacids to corresponding α -hydroxyketones in R-configuration. In this work, we prepared ALDC of Streptococcus thermophilus (StALDC) and explored its stereoselectivity on different substrates. The enzyme displays no enantioselectivity on substrate (±)-acetolactate, but R-selectivity on product acetoin, which are identical with the data reported for various ALDCs. When compound (±)-2-propionyl-2-hydroxybutyrate is used as a substrate, however, the enzyme exhibits S-selectivity on both substrate and product, namely it can only decarboxylate (S)-2-propionyl-2-hydroxybutyrate to generate (S)-4-hydroxy-3-hexanone rather than its R-isomer, which is totally discriminate from the data published for the ALDC of Bacillus subtilis. As far as we know, this is the first time that substrate dependent enantioselectivity of ALDC is reported and the feature of StALDC is also discussed on the basis of homology modeling and molecular docking experiments.

Glycyrrhizin, a High-Mobility Group Box 1 Inhibitor, Improves Lipid Metabolism and Suppresses Vascular Inflammation in Apolipoprotein E Knockout Mice.

BACKGROUND: High-mobility group box protein 1 (HMGB1) is known to have proinflammatory properties; however, the mechanisms by which HMGB1 influences immune responses during atherosclerosis (AS) development are not well understood. Thus, this study investigated the relationship between HMGB1 and vascular inflammation in Apoe-/- mice and whether glycyrrhizin (GLY), a small inhibitor of HMGB1, could have atheroprotective effects in AS. METHODS: Apoe-/- mice on a high-fat diet were treated with GLY (50 mg/kg) or vehicle by gavage once daily for 12 weeks, respectively. RESULTS: The GLY group exhibited significantly decreased serum lipid levels, atherosclerotic plaque deposition, and serum HMGB1 levels, as well as an increased Treg/Th17 ratio. The GLY group displayed increased interleukin-10 (IL-10) and IL-2 expression and decreased IL-17A and IL-6 expression. Furthermore, the GA treatment significantly reduced STAT3 phosphorylation in Th17 cells and increased STAT5 phosphorylation in Treg cells. CONCLUSIONS: Our findings indicate that the attenuation of atherosclerotic lesions in Apoe-/- mice by GLY might be associated with the amelioration of lipid metabolism abnormalities, inhibition of HMGB1 expression, and alterations in the Treg/Th17 ratio.

The Effects of High Mobility Group Box-1 Protein on Peripheral Treg/Th17 Balance in Patients with Atherosclerosis.

BACKGROUND: Atherosclerosis (AS) is defined as chronic inflammation of the vessel wall. The major objective of the this study was to explore the mechanism of Treg/Th17 imbalance and the role of high mobility group box-1 protein (HMGB1) on the balance in AS. METHODS: We detected the apoptotic ratios of Treg and Th17 cells in peripheral blood mononuclear cells (PBMCs) from subjects with AS and normal coronary arteries (NCA) by flow cytometry. The effects of recombinant HMGB1 (rHMGB1) on the proportion, apoptosis and differentiation of Treg and Th17 cells were analyzed using flow cytometry, qRT-PCR and ELISA. RESULTS: The frequencies of apoptotic Treg cells in the PBMCs from the subjects with AS were significantly higher than in those with NCA (p < 0.01). Stimulation of rHMGB1 obviously increased the level of Th17 cells and acid- related orphan receptor C (RORC) mRNA, and markedly decreased Treg cell frequency and the mRNA expression of factor forkhead family protein 3 (Foxp3) in the PBMCs. rHMGB1 played an obvious role in elevating Treg cell apoptosis ratio (p < 0.01). rHMGB1 treatment significantly decreased Treg cell ratio and IL-10 level, and increased Th17 cell ratio and IL-17A level induced from naïve CD4+ T cells. CONCLUSIONS: HMGB1 may modulate Treg/Th17 balance in patients with AS through inducing Treg cell apoptosis and promoting cell differentiation of Th17.

Plant Identity Exerts Stronger Effect than Fertilization on Soil Arbuscular Mycorrhizal Fungi in a Sown Pasture.

Arbuscular mycorrhizal (AM) fungi play key roles in plant nutrition and plant productivity. AM fungal responses to either plant identity or fertilization have been investigated. However, the interactive effects of different plant species and fertilizer types on these symbiotic fungi remain poorly understood. We evaluated the effects of the factorial combinations of plant identity (grasses Avena sativa and Elymus nutans and legume Vicia sativa) and fertilization (urea and sheep manure) on AM fungi following 2-year monocultures in a sown pasture field study. AM fungal extraradical hyphal density was significantly higher in E. nutans than that in A. sativa and V. sativa in the unfertilized control and was significantly increased by urea and manure in A. sativa and by manure only in E. nutans, but not by either fertilizers in V. sativa. AM fungal spore density was not significantly affected by plant identity or fertilization. Forty-eight operational taxonomic units (OTUs) of AM fungi were obtained through 454 pyrosequencing of 18S rDNA. The OTU richness and Shannon diversity index of AM fungi were significantly higher in E. nutans than those in V. sativa and/or A. sativa, but not significantly affected by any fertilizer in all of the three plant species. AM fungal community composition was significantly structured directly by plant identity only and indirectly by both urea addition and plant identity through soil total nitrogen content. Our findings highlight that plant identity has stronger influence than fertilization on belowground AM fungal community in this converted pastureland from an alpine meadow.

Enhanced photocatalytic performance of an Ag3PO4 photocatalyst via fullerene modification: first-principles study.

The coupling of carbon nanomaterials with semiconductor photocatalysts is a promising route to improve their photocatalytic performance. Herein, density functional theory was used to investigate the electronic structure, charge transfer, photocatalytic activity, and stability in a series of hybrid fullerene (C20, Li@C20, C26, Li@C26)/Ag3PO4(100) composites. When a Li atom is incorporated in fullerene, the adsorption energies significantly increase, although the change of interface distance is negligibly small due to the weak interface interaction. The charge transfer between constituents decreases with the C atom number of fullerene. Compared to pure Ag3PO4, the band gap of the composites is smaller, which enhances the visible-light absorption and photoinduced electron transfer. Most importantly, a type-II, staggered band alignment could be obtained in the C26-Ag3PO4(Li@C26-Ag3PO4) interface, leading to significantly reduced charge recombination and thus enhanced photocatalytic activity. These results reveal that fullerene modification would be an effective strategy to improve the photocatalytic performance of Ag3PO4 semiconductor photocatalysts.

Interleukin-33 Ameliorates Murine Systemic Lupus Erythematosus and Is Associated with Induction of M2 Macrophage Polarisation and Regulatory T Cells.

The innate cytokine IL-33 is increasingly recognised to possess biological effects on various immune cells. We have previously demonstrated elevated serum level of soluble ST2 in patients with active systemic lupus erythematosus suggesting involvement of IL-33 and its receptor in the lupus pathogenesis. This study sought to examine the effect of exogenous IL-33 on disease activity of pre-disease lupus-prone mice and the underlying cellular mechanisms. Recombinant IL-33 was administered to MRL/lpr mice for 6 weeks, whereas control group received phosphate-buffered saline. IL-33-treated mice displayed less proteinuria, renal histological inflammatory changes, and had lower serum levels of pro-inflammatory cytokines including IL-6 and TNF-α. Renal tissue and splenic CD11b+ extracts showed features of M2 polarisation with elevated mRNA expression of Arg1, FIZZI, and reduced iNOS. These mice also had increased IL-13, ST2, Gata3, and Foxp3 mRNA expression in renal and splenic tissues. Kidneys of these mice displayed less CD11b+ infiltration, had downregulated MCP-1, and increased infiltration of Foxp3-expressing cells. Splenic CD4+ T cells showed increased ST2-expressing CD4+Foxp3+ population and reduced IFN-γ+ population. There were no differences in serum anti-dsDNA antibodies and renal C3 and IgG2a deposit in these mice. Exogenous IL-33 was found to ameliorate disease activity in lupus-prone mice with induction of M2 polarisation, Th2 response, and expansion of regulatory T cells. IL-33 likely orchestrated autoregulation of these cells through upregulation of ST2 expression.

Methanotrophic community structure and activity under warming and grazing of alpine meadow on the Tibetan Plateau.

Knowledge about methanotrophs and their activities is important to understand the microbial mediation of the greenhouse gas CH(4) under climate change and human activities in terrestrial ecosystems. The effects of simulated warming and sheep grazing on methanotrophic abundance, community composition, and activity were studied in an alpine meadow soil on the Tibetan Plateau. There was high abundance of methanotrophs (1.2-3.4 × 10(8) pmoA gene copies per gram of dry weight soil) assessed by real-time PCR, and warming significantly increased the abundance regardless of grazing. A total of 64 methanotrophic operational taxonomic units (OTUs) were obtained from 1,439 clone sequences, of these OTUs; 63 OTUs (98.4%) belonged to type I methanotrophs, and only one OTU was Methylocystis of type II methanotrophs. The methanotroph community composition and diversity were not apparently affected by the treatments. Warming and grazing significantly enhanced the potential CH(4) oxidation activity. There were significantly negative correlations between methanotrophic abundance and soil moisture and between methanotrophic abundance and NH(4)-N content. The study suggests that type I methanotrophs, as the dominance, may play a key role in CH(4) oxidation, and the alpine meadow has great potential to consume more CH(4) under future warmer and grazing conditions on the Tibetan Plateau.

[Discussion on methods for locating Xuehai (SP10) acupoint].

The position of Xuehai (SP10) is clear, but its locating method is vague, resulting in the disunity of clinical application and even possibly affecting the curative effect. Also, when learning the meridians and acupoints, the beginners are often confused by this issue possibly due to: ① when the bone-length proportional measurement combined with anatomic symbol (combination method) was adopted, it is not clear that the patient should take a posture of knee extension or knee flexion; ② when the combination method used, it is difficult to find the highest point of muscle eminence in the case of patient with thin vastus medialis muscle and fuzzy body surface projection; ③the simple method for locating SP10 is widely used at present, can it replace the combination method to locate this acupoint accurately？Guided by these questions, we, in the present paper, reviewed the rela-ted textbooks, works and other literature to explore the standard position of SP10, and the standard and simple methods for locating this acupoint. Comprehending various opinions, we hold that SP10 should be positioned under the extended knee posture, then, the acupoint's horizontal ordinate "2 cun superior to the medial end of the base of the patella" is determined by using bone-length proportional measurement to measure 2 cun from the bottom to the tip of the patella. Then, the body surface anatomic symbol method is used, when, the patient is asked to stretch the leg and contract the vastus medialis muscle, the highest spot of muscular eminence is the SP10. If the patient's muscular protuberance is not obvious, the middle line between the medial and lateral margins of the vastus medialis muscle is used as the vertical ordinate, and its intersection with the abscissa is SP10. The simple method is easy in operation and has a reference value, but may frequently produce errors, hence, it is not a substitution for the combination method.

[Effects of ropivacaine hydrochloride on the proliferation, invasion and apoptosis of osteosarcoma cells and its mechanism].

Objective: To investigate the effects and molecular mechanism of ropivacaine hydrochloride on osteosarcoma cell proliferation, invasion, and apoptosis. Methods: The osteosarcoma doxorubicin-resistant cell line (U2OS/DOX) was established by gradually increasing the drug doses. U2OS/DOX cells were treated with ropivacaine hydrochloride at the concentrations of 0, 20, 50 and 100 µg/ml, respectively; as different concentrations treatment groups of ropivacaine hydrochloride. pcDNA3.1 and pcDNA3.1-Livin were transfected into U2OS/DOX cells and then treated with 100 µg/ml ropivacaine hydrochloride, which were defined as ropivacaine hydrochloride 100 µg/ml+pcDNA3.1 group, ropivacaine hydrochloride 100 µg/ml+pcDNA3.1-Livin group. MTT was used to detect the cell proliferation inhibition rate and inhibitory concentration (IC50). Western blot was used to detect the expressions of cyclin-dependent kinase inhibitor 1A (P21) and activated cysteine aspartic protease-3 (Cleaved Caspase-3), E-cadherin, matrix metalloproteinase 2 (MMP-2) and Livin; clone formation experiments were used to detect the number of cell clones formed; flow cytometry was used to detect apoptosis; Transwell was used to detect cell migration and invasion; real-time fluorescent quantitative PCR (RT-qPCR) was used to detect Livin mRNA expression. Results: When the concentration of doxorubicin was more than 1 µg/ml, the proliferation inhibition rate of osteosarcoma cells U2OS was significantly increased in a concentration-dependent manner (P＜0.05); when the concentration of doxorubicin was more than 10 µg/ml, the proliferation inhibition rate of osteosarcoma resistant cell U2OS/DOX was significantly increased, and it was dose-dependent (P＜0.05). In U2OS/DOX cells treated with ropivacaine hydrochloride, the expressions of P21, Cleaved Caspase-3, and E-cadherin were increased significantly, the expression of MMP-2 was decreased significantly, the cell proliferation inhibition rate was increased significantly, the number of colony formation was decreased significantly, and the cells apoptosis rate was increased significantly, the number of cell migration and invasion was decreased significantly, and the expression of Livin was significantly reduced, in a concentration-dependent manner (P＜0.05). Overexpression of Livin partially reversed the inhibitory effect of ropivacaine hydrochloride on proliferation, migration, invasion, and promotion effect on apoptosis of cell U2OS/DOX. Conclusion: Ropivacaine hydrochloride can significantly inhibit the proliferation, migration and invasion of doxorubicin-resistant osteosarcoma cells, and significantly promote osteoma cell apoptosis. The mechanism may be related to Livin.

The chemical mechanisms of the enzymes in the branched-chain amino acids biosynthetic pathway and their applications.

l-Valine, l-isoleucine, and l-leucine are three key proteinogenic amino acids, and they are also the essential amino acids required for mammalian growth, possessing important and to some extent, special physiological and biological functions. Because of the branched structures in their carbon chains, they are also named as branched-chain amino acids (BCAAs). This review will highlight the advance in studies of the enzymes involved in the biosynthetic pathway of BCAAs, concentrating on their chemical mechanisms and applications in screening herbicides and antibacterial agents. The uses of some of these enzymes in lab scale organic synthesis are also discussed.

Preparation of a whole cell catalyst overexpressing acetohydroxyacid synthase of Thermotoga maritima and its application in the syntheses of α-hydroxyketones.

The large catalytic subunit of acetohydroxyacid synthase (AHAS, EC 2.2.1.6) of Thermotoga maritima (TmcAHAS) was prepared in this study. It possesses high specific activity and excellent stability. The protein and a whole cell catalyst overexpressing the protein were applied to the preparation of α-hydroxyketones including acetoin (AC), 3-hydroxy-2-pentanone (HP), and (R)-phenylacetylcarbinol (R-PAC). The results show that AC and HP could be produced in high yields (84% and 62%, respectively), while R-PAC could be synthesized in a high yield (about 78%) with an R/S ratio of 9:1. Therefore, TmcAHAS and the whole cell catalyst overexpressing the protein could be practically useful bio-catalysts in the preparation of α-hydroxyketones including AC, HP, and R-PAC. To the best of our knowledge, this is the first time that bacterial AHAS was used as a catalyst to prepare HP with a good yield, and also the first time that TmcAHAS was employed to synthesize AC and R-PAC.

Abnormal circadian rhythms are associated with plaque instability in acute coronary syndrome patients.

AIM: Acute coronary syndrome (ACS), a leading cause of morbidity and mortality worldwide, is among the most serious cardiovascular diseases. Circadian rhythms are present in almost all organisms. In clinical practice, we have found that ACS is closely related to these circadian rhythms. However, the relationship between circadian rhythms and plaque instability in ACS patients is incompletely understood. The aim of this study is to provide new insights into the relationship between circadian rhythms and plaque instability in ACS patients. METHODS: We enrolled patients with ACS and individuals with normal coronary artery function in this study. The Athens Insomnia Scale (AIS), Pittsburgh Sleep Quality Index (PSQI), International Physical Activity Questionnaire (IPAQ) and Healthy Diet Score (HDS) were used to evaluate circadian rhythms. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess the mRNA expression levels of muscle aryl hydrocarbon receptor nuclear translocator-like protein 1 (Bmal1), circadian locomotor output cycles kaput (Clock), Cryptochrome1 (Cry1), Period2 (Per2), nuclear receptor subfamily 1, group D, member 1 (Rev-erbα), and matrix metalloproteinases MMP2 and MMP9. RESULTS: AIS scores and PSQI scores were significantly higher in patients with ST segment elevation myocardial infarction (STEMI), non-ST segment elevation myocardial infarction (NSTEMI), and unstable angina pectoris (UA) than in the normal controls (NCs) (P < 0.05). The IPAQ scores of the NCs and patients with UA were significantly higher than in patients with STEMI and NSTEMI (P < 0.05). Notably higher HDS scores were recorded for the NCs compared to those of patients with UA, NSTEMI, and STEMI (P < 0.05). Consistent with these findings, compared with the NCs, the lowest levels of Bmal1, Clock, Cry1, Per2 and Rev-erbα mRNAs were detected in patients with STEMI, followed by patients with NSTEMI and then patients with UA (P < 0.05). Furthermore, the levels of MMP2 and MMP9 mRNA were significantly higher in the patients with STEMI, NSTEMI, and UA than those in the NCs (P < 0.05). In addition, we found that the levels of MMP mRNA negatively correlated with the levels of clock genes mRNAs (P < 0.05, respectively). CONCLUSIONS: Based on our data, the circadian rhythms and clock genes are correlatively with the occurrence of ACS, and the expression levels of clock genes are negatively correlated with plaque stability in ACS patients.

HMGB1Modulates the Treg/Th17 Ratio in Atherosclerotic Patients.

AIM: Atherosclerosis (AS) characterized as a chronic inflammatory disease. Multiple immune cells and inflammatory cytokines, such as high mobility group protein (HMGB1), regulatory T (Treg) cells, T helper (Th17) cells, and inflammation-related cytokines, play a key role in its pathophysiology. A large number of studies report that HMGB1 and Th17 cells may promote atherosclerosis progression, whereas Treg cells may play a protective role in atherosclerosis; thus, alterations in the Treg/Th17 ratio may exist in atherosclerosis diseases. Up till now, the relationships between HMGB1 levels and the Treg/Th17 ratio remain incompletely understood. The major purpose of this study was to investigate the relationship between HMGB1 levels and the Treg/Th17 ratio in patients with coronary artery atherosclerotic plaques. METHODS: We enrolled patients with coronary atherosclerosis and normal coronary artery as the research subjects. Flow cytometry was used to analyze the Treg cells, the Th17 cells frequency, and the Treg/Th17 ratio. Otherwise, real-time polymerase chain reaction was used for assays the mRNA expressions of HMGB1, retinoic acid-related orphan nuclear receptor C (RORC), and forkhead-winged helix transcription factor (Foxp3). Moreover, enzyme-linked immunosorbent assays were used to detect the level of protein and cytokines, such as HMGB1, IL-10, TGF-ß1, IL-17A, and IL-23. RESULTS: Using flow cytometry, we observed a significantly increased of Th17 cell frequency, whereas Treg cell frequency significantly decreased in atherosclerotic patients. Consistently, the levels of RORC mRNA were significantly increased in coronary atherosclerosis (AS) group compared to normal coronary artery (NCA) group (P＜0.01). In contrast, the expression of Foxp3 mRNA was markedly lower in the AS group than in the NCA group (P＜0.01). Furthermore, we observed the serum concentrations of HMGB1, IL-17A, and IL-23 were significantly higher in the AS group than in the NCA group (P＜0.01, respectively), whereas the concentrations of serum IL-10 and TGF-ß1 were significantly lower in the AS group than in the NCA group (P＜0.01, respectively). In addition, we also found that HMGB1 levels showed negative correlation with the Treg/Th17 ratio in the two groups (r=－0.6984, P＜0.01). CONCLUSIONS: The data in our study indicated that HMGB1 may promote atherosclerosis progression via modulating the imbalance in the Treg/Th17 ratio.

Non-covalent functionalization of WS2 monolayer with small fullerenes: tuning electronic properties and photoactivity.

Atomically thin two-dimensional transition metal dichalcogenides (TMDCs) heterostructures have recently attracted growing interest due to their massive potential in solar energy applications due to their band gap in the visible spectral range and extremely strong light-matter interactions. Herein, heterostructures composed of WS2 and MoS2 monolayers, as representative TMDCs, with small fullerenes (B12 and C20) are investigated to explore their applications in solar energy conversion using first principles calculations based on density functional theory (DFT). The WS2 (MoS2) monolayer and fullerene form a van der Waals (vdW) heterostructure. Compared to pure monolayers, the heterostructures have a smaller band gap, which favours enhancing visible light absorption. The amount of charge transfer at the interface induced by vdW interactions depends on the type of fullerene. Most importantly, a type-II staggered band alignment is formed between WS2 (MoS2) and fullerene with the latter possessing the higher electron affinity which results in the robust separation of photoexcited charge carriers between them. These results indicate that the electronic properties and photoactivity of TMDCs monolayers can be tuned by non-covalent coupling with small fullerenes, thus meeting the needs of various applications.