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In our previous study, we discovered that resveratrol (RSV) had potential tumor-promoting effect on pancreatic cancer (PaCa) via up-regulation of VEGF-B. Therefore, we assumed that a pharmacological inhibitor of VEGF-B should potentiate the anti-tumor effect of RSV on PaCa. Real-time PCR and western blotting were used to examine VEGF-B mRNA and protein levels. Cell viability and cell apoptosis were assessed by CCK-8 assay and flow cytometry analysis, respectively. PaCa cell-bearing nude mice were used to evaluate the anti-cancer effects of single treatment or co-administration of RSV and gemcitabine (GEM). We found that treatment with GEM alone dramatically decreased VEGF-B expression in comparison with control group, indicating that GEM is a potential pharmacological inhibitor of VEGF-B in PaCa. The co-administration of RSV and GEM significantly lowered expression of VEGF-B and increased phosphorylation level of GSK3β at Ser9 when compared to RSV alone treatment either in vitro or in vivo. Combination of RSV and GEM significantly increased cell death and apoptosis of PaCa cells in vitro and inhibited tumor growth in vivo in comparison with RSV or GEM alone treatment. Furthermore, we found that the anti-tumor effect in combination group was dramatically weakened after VEGF-B overexpressed in PaCa cells. These results suggest that VEGF-B signaling pathway plays an important role in the development of PaCa and combination of GEM and RSV would be a promising modality for clinical PaCa therapy.

Highly efficient photo-assisted electrocatalysis for methanol oxidation reaction (MOR) realizes the conversion of solar and chemical energy into electric energy simultaneously. Here we report a Pt-MXene-TiO2 composite for highly efficient MOR via a photoactive cascaded electro-catalytic process. With light (UV and visible light) irradiation, MXene-TiO2 serves as the photo active centre (photoinduced hole) to activate the methanol molecules, while Pt particles are the active centre for the following electro-catalytic oxidation of those activated methanol molecules. Pt-MXene-TiO2 catalyst exhibits a lower onset potential (0.33 V) and an impressive mass activity of 2,750.42 mA·mg−1Pt under light illumination. It represents the highest MOR activity ever reported for photo-assisted electrocatalysts. Pt-MXene-TiO2 also shows excellent CO tolerance ability and stability, in which, after long-term (5,000 s) reaction, still keeps a high mass activity of 1,269.81 mA·mg−1Pt (62.66% of its initial activity). The photo-electro-catalytic system proposed in this work offers novel opportunities for exploiting photo-assisted enhancement of highly efficient and stable catalysts for MOR.

Using amendments is a cost-effective method to soil cadmium (Cd) remediation, whereas knowledge about how different amendments and rates affect remediation efficiency remains limited. This study aimed to evaluate the impacts of different types and amounts of amendments on soil Cd immobilization and its uptake by plants. Biochar (BC), zeolite (ZE), humic acid (HA), superphosphate (SP), lime (L), and sodium sulfide (SS) were applied at three rates (low, medium, and high) ranging from 0.5 to 5%. The concentration of CaCl2-extractable Cd was considerably affected by the amendments, except HA, and the high doses achieved better immobilization effects than the low doses did. The addition of amendments decreased weak acid soluble Cd by 4.1–44.0% but slightly increased the fractions of oxidizable and residual Cd. These amendments (except BC and HA dose of 1%) decreased Cd accumulation in grains by 1.3–68.8% and (except SP) in roots by 16.3–65.5% compared with the control. The SP efficiently immobilized Cd but posed a potential soil acidification risk. Moreover, SS treatment increased the soil electrical conductivity (EC) value and restricted the growth of wheat, possibly due to high-salt stress. BC, ZE, and L exerted significant effects on the reduction in available Cd as the application rate increased. These amendments enhanced Cd immobilization mainly by changing Cd availability in soil and influencing its redistribution in different fractions in soil and root uptake by plants. This study concluded that BC-5%, ZE-1%, and L-0.5% can be used for Cd immobilization in acidic or neutral soils.

Atherosclerosis is a major pathology for cardiovascular diseases (CVDs). Clinically, the intermittent fasting (IF) has been observed to reduce the risk of CVDs. However, the effect of IF on the development of atherosclerosis has not been fully elucidated. Herein, we determined the protection of IF against high-fat diet–induced atherosclerosis in pro-atherogenic low-density lipoprotein receptor deficient (LDLR-/-) mice and the potentially involved mechanisms. The LDLR-/- mice were scheduled intermittent fasting cycles of 3-day HFD feeding ad libitum and 1 day fasting, while the mice in the control group were continuously fed HFD. The treatment was lasted for 7 weeks (∼12 cycles) or 14 weeks (∼24 cycles). Associated with the reduced total HFD intake, IF substantially reduced lesions in the en face aorta and aortic root sinus. It also increased plaque stability by increasing the smooth muscle cell (SMC)/collagen content and fibrotic cap thickness while reducing macrophage accumulation and necrotic core areas. Mechanistically, IF reduced serum total and LDL cholesterol levels by inhibiting cholesterol synthesis in the liver. Meanwhile, HFD-induced hepatic lipid accumulation was attenuated by IF. Interestingly, circulating Ly6Chigh monocytes but not T cells and serum c-c motif chemokine ligand 2 levels were significantly reduced by IF. Functionally, adhesion of monocytes to the aortic endothelium was decreased by IF via inhibiting VCAM-1 and ICAM-1 expression. Taken together, our study indicates that IF reduces atherosclerosis in LDLR-/- mice by reducing monocyte chemoattraction/adhesion and ameliorating hypercholesterolemia and suggests its potential application for atherosclerosis treatment.

Rheumatoid arthritis (RA) is a chronic, systemic, synovitis-based inflammatory disease with unknown etiology. Neutrophils play important roles in the pathogenesis of RA. Apoptosis and NETosis of neutrophils are two major mechanisms of programmed cell death that differ in their morphological characteristics and effects on the immune system. In rheumatoid arthritis, delayed neutrophil apoptosis amplifies the inflammatory response; and massive release of NETs and their components may cause tissue damage and provide self-antigens. Emodin is a natural anthraquinone derivative that occurs in many widely used Chinese medicinal herbs. In this study, we evaluated the effect of emodin on a murine adjuvant-induced arthritis (AA) model of RA in vivo and on neutrophil apoptosis and NETosis in vitro. Our results show that emodin alleviated AA by reducing neutrophil infiltration and proinflammatory cytokine (interleukin-6, interferon-gamma and tumor necrosis factor-α) release. Emodin promoted apoptosis and inhibited autophagy and NETosis in neutrophils. These findings indicate that emodin represents a potential therapeutic agent for RA.

Electrochemical reduction of carbon dioxide (CO2RR) to useful chemicals and fuels is one of the promising methods to reduce the accumulated greenhouse gas in the atmosphere and simultaneously satisfy sustainable energy demands. Metallic Ag has been reported in numerous studies for its excellent properties in CO2 reduction. However, most Ag catalysts require a large overpotential to realize high selectivity and the Faradaic efficiency (FE) is relatively low. Moreover, the synthetic methods of efficient Ag catalysts are usually complicated and time-consuming. In this work, a phosphate silver-derived silver (PD-Ag) electrocatalyst was fabricated by a quick facile electroreduction method, showing superior performance for the selective reduction of CO2 to CO. The maximum FE of PD-Ag could reach 97.3% with a potential of −0.7 V vs RHE, and a current density of 2.93 mA cm–2. It is demonstrated that a 19-fold increase of the electrochemically active surface area (ECSA) is obtained for PD-Ag compared to polycrysta...

Water can be split into hydrogen (H2) and hydrogen peroxide (H2O2) in an environment-friendly manner through photocatalysis by CoO, which is a promising strategy to alleviate the energy crisis. However, the stability of CoO remains a great challenge because of the oxidation effect of the product H2O2. Herein, titanium silicalite-1 (TS-1) was employed as a framework to obtain and anchor monodisperse CoO nanodots, improve CoO photocatalytic performance, and efficiently separate the oxidizing species from CoO by adsorbing the resulting H2O2. As a result, TS-1 prevented CoO from aggregation, surface oxidation, and rapid inactivation. CoO-TS-1 showed H2 and H2O2 production rates of 1460 μmol h-1 gCoO-1 and 1390 μmol h-1 gCoO-1, respectively, with a high photostability for about 168 h. In addition, the efficiently harvested H2O2 was directly used in the oxidation of cyclohexane to cyclohexanol and cyclohexanone with a selectivity of up to 89.48%. This work paves a new way for the design of an efficient and stable photocatalyst as well as product utilization.

The combined pollution of heavy metals and antibiotics in soil has attracted increasing attention due to their negative effects on plant growth. The aims of this study were to evaluate the phytotoxicity of single and combined sulfamethazine (SMT) and cadmium (Cd), selected as target pollutants in soil, on growth and physiological response of pakchoi (Brassica chinensis L.). Results revealed that the soil spiked with 10 mg kg−1 Cd inhibited the pakchoi growth regardless of SMT addition. The combined effect of SMT and Cd stress on uptake of SMT or Cd by pakchoi were concerned with their combined concentration. The combined influence of high concentrations SMT and Cd (1 and 10 mg kg−1) exposure on the Cd content of pakchoi showed antagonistic effects and synergistic effects, respectively. Besides, oxidative substances and enzyme activity of pakchoi tissue were affected by Cd and SMT exposure in the soil, particularly by their joint stress. This mainly expressed as the increase of malondialdehyde (MDA), H2O2 content and antioxidant enzyme activity (superoxide dismutase (SOD), peroxidase (POD), catalase (CAT)), which could be ascribed to the induction of Cd and SMT stress. Additionally, the SMT-Cd combined stress caused more reduction in nutrients (vitamin C and sugar) of pakchoi than the correspondingly single Cd stress. In conclusion, the SMT and Cd in soil lead to their accumulation and oxidative damage in pakchoi, which disturb the antioxidant defense system and ultimately adversely affect growth and quality of pakchoi.

Hydrogen and oxygen produced by water splitting under solar energy are ideal future energy sources. At present, obtaining the efficient, stable and inexpensive photocatalyst for photocatalytic overall water splitting is still a huge challenge. Cobalt phosphate (Co3PO4, CoPi) possesses proper band positions for water splitting. However, the fast recombination of photogenerated electron and hole pairs for CoPi restricts its application. Herein, strongly coupling Co3PO4-carbon dots (CoPi-CDs) composite was constructed as an effective strategy to depress the fast recombination behavior of photogenerated electron and hole pairs. CoPi-CDs show superior photocatalytic water splitting activity than that of single CoPi. When the concentration of CDs in the composite is 0.002 gCDs/gcatalyst, the hydrogen production rate was obtained for approximately 0.592 μmol h−1, as well as the oxygen evolution rate about 0.258 μmol h−1 (with 2:1 stoichiometry), which are both nearly 33 times than that of pristine CoPi. This enhanced photocatalytic activity of CoPi-CDs should ascribe to the efficient coupling effect between CoPi and CDs, which allows fast electron transfer at the interface of CoPi and CDs and thus effectively boosts the photocatalytic water splitting. The strongly coupling nanocomposites should be inspiring for further nanocomposite building for photocatalytic overall water splitting.

Epoxides are an extremely important class of chemical intermediates in the chemical industry due to the versatility of epoxides in preparing many fine and specialty chemicals. However, designing more active and selective heterogeneous catalysts in epoxidation is still a priority and a challenge. In this work, we demonstrate the synthesis of two new Ag/polyoxometalate-based coordination polymers (Ag8(mttz)4(H2O)[PWVWVI11O40]·H2O (1) and Ag8(mttz)4(H2O)[PMoVMoVI11O40] (2), mttz = 5-methylthio-2H-tetrazole) that are highly active for the selective oxidation of cis-cyclooctene to epoxycyclooctane under mild conditions (solvent-free, atmospheric pressure, 70 °C with H2O2 as the oxidant under visible light). It is worth noting that compound 1 possesses abundant exposed active edge sites of Ag, resulting in the catalytic performance achieved in the selective oxidation of cis-cyclooctene to epoxycyclooctane being superior to its components (metal, polyoxometalates and ligand) and compound 2 with the conversion/selectivity to epoxycyclooctane of 70.15/99.68%, respectively. The excellent photocatalytic activity of compound 1 should be attributed to the synergy of the components after coordination polymerization and its structure with exposed active edge sites of Ag.

A novel green/red dual-emission carbon dots-based phosphor (named as GRCDs phosphor) was successfully prepared by introducing calcium hydroxide [Ca(OH)2] as matrix material mixed with green-emitting carbon dots (CDs) for the first time. The addition of Ca(OH)2 not only prevents fluorescent self-quenching caused by polymerization of CDs in the solid state but also promotes the red emission of CDs due to abundant functional groups on the surface. Furthermore, the detailed characterizations of the structure and optical properties show that the hydroxyl groups play a crucial role for the red emission of GRCDs phosphor. As-prepared GRCDs phosphor possesses outstanding thermal stability as well as excellent water stability. This finding provides a new way for the development of CDs-based phosphors.

In this work, the structure-property relationship of fused-ring electron acceptors is briefly discussed and the principle of molecular design is presented. Based on this principle, perylene diimide (PDI) was cracked by inserting thiophene and thieno[3,2- b ]thiophene (TT) to design and synthesize a novel A-D-A (acceptor-donor-acceptor) small molecule DNIT-TT2T, which served as a non-fullerene acceptor material in our fabricated organic solar cells (OSCs). DNIT-TT2T shows excellent thermal stability, it possesses a broad absorption by covering the wavelength range of 300–600 nm and relatively high LUMO energy level of −3.75 eV, which is close to the theoretically calculated value. The power conversion efficiency (PCE) of OSCs based on the blend of P3HT donor and DNIT-TT2T acceptor (1:1, w/w) is found to be 1.25%, with a high open-circuit voltage ( V oc ) of 0.88 V, indicating that 1,8-naphthalimide (NI) based molecules are promising acceptors for non-fullerene polymer solar cells and excellent photovoltaic properties can be achieved by rationally designing the molecules.

Mn4+-activated red phosphors have attracted considerable attention as promising red components in the spectra of white light emitting diodes (WLEDs) to achieve warm white light with superior performance. Herein, a novel red phosphor based on Mn4+-doped dodec-fluoride Li3Na3Al2F12:Mn4+ (LNAF:Mn) with microcubic morphology was obtained at room temperature. To elucidate the underlying relationship between the crystal structure and photoluminescence of LNAF:Mn, a phosphor LiNa2AlF6:Mn4+ with similar composition has been prepared, and their morphology and optical properties were comparatively investigated. The emission of the red phosphor LNAF:Mn is blue shifted compared to LiNa2AlF6:Mn4+ suggesting that the chromaticity coordinates of LANF:Mn are closer to the ideal red point (0.67, 0.33). The luminescence properties of LNAF:Mn have been improved by optimizing the synthetic conditions. This work exhibits a strategy to explore a novel Mn4+-doped fluoride except for the identified hexa-fluorides. Employing the as-prepared red LNAF:Mn as a red component, a high-performance WLED with a correlated color temperature (CCT) of 3874 K and a color rendering index (CRI) of 90.6 was obtained. This suggests the phosphor is a potential commercial red phosphor in warm WLEDs.

A couple of novel electrochromic materials poly(2,3,4,5-tetrakis(2,3-hydrothieno[3,4- b ]dixin-5-yl)-1-methyl-1 H -pyrrole) (P( t -EDOT-mPy)) and poly(5,5′,5′′,5′′′-(thiophene-2,3,4,5-tetrayl) tetrakis(2,3-dihydrothieno[3,4- b ][1,4]dioxine)) (P( t -EDOT- Th)) are electrodeposited via multi-position polymerization of their tetra -EDOT substituted monomers t -EDOT-mPy and t -EDOT-Th, respectively. Compared with the linear 2D structured poly(thiophene) ( E g=2.2 eV) and poly(2,5-bis(2,3- dihydrothieno[3,4- b ][1,4]dioxin-5-yl)thiophene) ( E g=1.7 eV), P( t -EDOT-Th) ( E g=1.62 eV) has the lowest band gap. Hence, we speculate that the band gaps of the two polymers, having 3D structures, are decreased in contrast to non-substituted polymers or bi -EDOT substituted polymers, thiophene and 1-methyl-1 H -pyrrole. The results indicated that P( t -EDOT-Th) thin films are more stable and show higher transmittance amid two polymers, which may find their utilization in organic optoelectronics.

Thieno[3,2-b]thiophene (TT) monomers end-capped with 3,4-ethylenedioxythiophene (EDOT) moieties are electropolymerized to form π-conjugated polymers with distinct electrochromic (EC) properties. Steric and electronic factors (electron donor and acceptor substituents) in the side groups of the TT core, as well as the structure of the polymer backbone strongly affect the electrochemical and optical properties of the polymers and their electrochromic characteristics. The studied polymers show low oxidation potentials, tunable from–0.78 to +0.30 V (vs. Fc/Fc+) and the band gaps from 1.46 to 1.92 eV and demonstrate wide variety of color palettes in polymer films in different states, finely tunable by structural variations in the polymer backbone and the side chains. EC materials of different colors in their doped/dedoped states have been developed (violet, deep blue, light blue, green, brown, purple-red, pinkish-red, orange-red, light gray, cyan and colorless transparent). High optical contrast (up to 79%), short response time (0.57–0.80 s), good cycling stability (up to 91% at 2000 cycles) and high coloration efficiency (up to 234.6 cm2 C–1) have been demonstrated and the influence of different factors on the above parameters of EC polymers have been discussed.

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by symmetric polyarthritis with swelling and pain at synovial joints. In RA patients, delayed neutrophil apoptosis amplifies the inflammatory response and massively released neutrophil extracellular traps (NETs) induce tissue damage and provide self-antigens. Andrographolide (AD) is the major active labdane diterpenoid derived from Andrographis paniculata, which has multiple pharmacological effects, including hepatoprotection, anti-angiogenesis, anti-thrombosis, and anti-inflammation. In the present study, we investigated the effect of AD on an adjuvant-induced arthritis (AA) murine model of RA and found that AD alleviated murine arthritis by reducing neutrophil infiltration and NETosis in the ankle joints and relieved the systematic inflammation. In vitro experiments showed that AD accelerated the apoptosis of lipopolysaccharide-activated neutrophils and inhibited autophagy-dependent extracellular traps formation of neutrophils. These findings suggest that AD has considerable potential for RA therapy.

Rheumatoid arthritis (RA) is a prototypical autoimmune disorder mainly characterized by joint inflammation and cartilage destruction. Neutrophils actively take part in the initiation and progression of RA. Neutrophils express inflammatory mediators, including cytokines and chemokines. Aberrant formation of neutrophil extracellular traps (NETs) has been demonstrated in the pathogenesis of RA. Thus, neutrophils are regarded as important therapeutic targets in RA treatment. Quercetin is one of the major flavonoids found in fruits and vegetables. Previous studies have demonstrated that quercetin is a potential agent for the treatment of RA. However, the underlying antiarthritic mechanism of quercetin has not been investigated clearly. In this study, we analyzed the therapeutic mechanism of quercetin for RA. Our results showed that quercetin ameliorates inflammation in RA mice by inhibiting neutrophil activities. Quercetin inhibited neutrophil infiltration and reduced the plasma levels of inflammatory cytokines. Quercetin promoted the apoptosis of activated neutrophils. In addition, quercetin inhibited NET formation by suppressing autophagy. These findings suggest that quercetin may be an alternative agent for the treatment of RA by inhibiting neutrophil activities.

Environmental stimuli-triggered stomatal movement is a key physiological process that regulates CO2 uptake and water loss in plants. Stomata are defined by pairs of guard cells that perceive and transduce external signals, leading to cellular volume changes and consequent stomatal aperture change. Within the visible light spectrum, red light induces stomatal opening in intact leaves. However, there has been debate regarding the extent to which red-light-induced stomatal opening arises from direct guard cell sensing of red light versus indirect responses as a result of red light influences on mesophyll photosynthesis. Here we identify conditions that result in red-light-stimulated stomatal opening in isolated epidermal peels and enlargement of protoplasts, firmly establishing a direct guard cell response to red light. We then employ metabolomics workflows utilizing gas chromatography mass spectrometry and liquid chromatography mass spectrometry for metabolite profiling and identification of Arabidopsis guard cell metabolic signatures in response to red light in the absence of the mesophyll. We quantified 223 metabolites in Arabidopsis guard cells, with 104 found to be red light responsive. These red-light-modulated metabolites participate in the tricarboxylic acid cycle, carbon balance, phytohormone biosynthesis and redox homeostasis. We next analyzed selected Arabidopsis mutants, and discovered that stomatal opening response to red light is correlated with a decrease in guard cell abscisic acid content and an increase in jasmonic acid content. The red-light-modulated guard cell metabolome reported here provides fundamental information concerning autonomous red light signaling pathways in guard cells.

Nitrogen (N) fertilizer application provides available N and affects indigenous soil N availability, inducing added N interaction (ANI). However, limited information is available on the impacts of inhibitors combined with organic substances on ANI. A microcosm experiment was conducted to examine the effects of the additions of nitrification inhibitor (dicyandiamide [DCD]), urease inhibitor (hydroquinone [HQ]), and glucose on ANI. In non-glucose treatments, positive ANI was observed at the initial stage of incubation. DCD addition generally increased ANI. Conversely, HQ addition decreased ANI. Glucose application led to a significantly negative ANI caused by net microbial immobilization at the beginning. ANI recovered because of the remineralization of immobilized N. Glucose combined with DCD and HQ further decreased ANI up to 24.4% and 30.7% and retarded the appearance of positive ANI by 2.6 and 6.0 days, respectively, compared with the corresponding treatment without inhibitor. ANI was primarily driven by biotic processes, and the contribution of abiotic processes, such as isotope displacement reaction in the fixed ammonium (NH4+) pool, to ANI ranged from 15.6% to 31.0%. This contribution increased with DCD and glucose additions, but decreased with HQ application. Generally, DCD addition tended to hold urea-derived N in soil and enhanced the availability of indigenous soil N, whereas HQ addition resulted in a reverse tendency. Glucose amendment remarkably induced the negative ANI and reduced the availability of N derived from either fertilizer or indigenous soil. These results can provide helpful implications for optimizing N management practices and remaining N availability.

A series of three polymers based on a thieno[3,2-b]thiophene core is synthesized and polymerized via electrochemical polymerization. The addition of benzene and thiophene rings as two different types of substituents on the 3,6-position of the thieno[3,2-b]thiophene core brings about a variance in color changing, optical contrast and morphological demeanor. Electrochromical studies demonstrate that P1 and P2 switch between deep blue neutral and colorless transparent oxidized states, while P3 switches between violet and light green transmissive states. Amid the three polymers, P1 shows the highest optical contrast (71%) in the visible region with complete coloring and bleaching in just 1.10 s and 1.80 s, respectively. In addition, all three polymers reveal about 60% of the transmittance change in the near-IR region, which endows them with commendable applications in NIR electrochromic devices. AFM images depict an augmented surface roughness due to the introduction of alkyl chains in the thieno[3,2-b]thiophene core, which gives rise to a better stability of the polymer thin film.

Two thieno[3,2-b]thiophene based polymers (poly[2,5-bis(2,3-dihydro-thieno[3,4-b][1,4]dioxin-5-yl)thieno[3,2-b]thiophene] (P(2,5-BTE)) and poly[3,6-bis-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)thieno[3,2-b]thiophene] (P(3,6-BTE))) were synthesized by an electrochemical method. By alternating the 3,4-ethylenedioxythiophene (EDOT) position along the polymer backbone we studied the electrochemical and optical properties by comparing the 2,5- and 3,6-positions on the thieno[3,2-b]thiophene unit. The theoretically calculated bandgaps and ultraviolet-visible spectrum peaks of the two dimers are in good agreement with the polar energy and peak range in the ultraviolet-visible and near-infrared (UV-Vis-NIR) spectrum, which helps us to comprehend the process of electrochemical polymerization and indicates that P(2,5-BTE) has a more conjugated structure than P(3,6-BTE). With the increase in voltage, both of the polymers gradually transform to their quinoid structures. Effective color tuning by changing the position of the EDOT units is the noteworthy property of P(2,5-BTE) and P(3,6-BTE), which makes them suitable electrochromic materials.

Solar water splitting via graphitic carbon nitride (g-C3N4) has achieved extensive attention in recent years. However, g-C3N4 usually suffers from low efficiency and poor stability. Besides, the difficulty lying in the gas mixture separation remains as a big challenge. Herein, a one-pot salt-assisted method was proposed to fabricate the cobalt-doped highly mesoporous g-C3N4 (Co-mCN) photocatalysts for efficient overall water splitting into H2 and H2O2. The adjustable Co doping not only improves the charge separation efficiency, but also enhances the tolerance of g-C3N4 against H2O2 poison. The optimal production for Co-mCN catalysts is gained to be 1.82 μmol h−1 and 1.65 μmol h−1 for H2 and H2O2 respectively, while an apparent quantum efficiency (AQE) of 2.2% at 420 nm and a working life for more than 216 h are also achieved. Moreover, it is demonstrated that the produced H2O2 can be easily collected with titanium silicalite molecular sieve (TS-1) as a reusable H2O2 carrier and directly applied in catalyzing cyclohexane oxidation into cyclohexanone and cyclohexanol mixture with 100% selectivity and 0.11% conversion efficiency. This work provides a new thinking and strategy for realizing overall water splitting, manipulating the products and extending the practical applications of g-C3N4 materials in chemical industry.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by cellular infiltration into the joints and cartilage destruction. Neutrophils play a crucial role in the pathogenesis of RA. Triptolide (TP) is a bioactive compound derived from Tripterygium wilfordii Hook F, which has been used in folk medicine as a treatment for a variety of inflammatory disorders, including RA, for many centuries. Previous studies have shown that TP possesses anti-arthritic activity. However, the anti-arthritic mechanism of TP remains to be fully defined. In the present study, we used the adjuvant-induced arthritis (AA) murine model of RA to investigate the impact of TP on RA and neutrophil function. TP alleviated AA by reducing neutrophil recruitment and suppressing the expression of interleukin-6 and tumour necrosis factor-α in vivo. TP also suppressed the expression of pro-inflammatory cytokines in neutrophils, promoted neutrophil apoptosis and inhibited the migration, NETosis and autophagy of neutrophils in vitro. Based on our findings, TP effectively ameliorates RA by down-regulating neutrophil inflammatory functions, indicating that TP represents a potential therapeutic agent for RA.

Drought can severely damage crops, resulting in major yield losses. During drought, vascular land plants conserve water via stomatal closure. Each stomate is bordered by a pair of guard cells that shrink in response to drought and the associated hormone abscisic acid (ABA). The activation of complex intracellular signaling networks underlies these responses. Therefore, analysis of guard cell metabolites is fundamental for elucidation of guard cell signaling pathways. Brassica napus is an important oilseed crop for human consumption and biodiesel production. Here, non-targeted metabolomics utilizing gas chromatography mass spectrometry (GC-MS/MS) and liquid chromatography mass spectrometry (LC-MS/MS) were employed for the first time to identify metabolic signatures in response to ABA in B. napus guard cell protoplasts. Metabolome profiling identified 390 distinct metabolites in B. napus guard cells, falling into diverse classes. Of these, 77 metabolites, comprising both primary and secondary metabolites were found to be significantly ABA responsive, including carbohydrates, fatty acids, glucosinolates, and flavonoids. Selected secondary metabolites, sinigrin, quercetin, campesterol, and sitosterol, were confirmed to regulate stomatal closure in Arabidopsis thaliana, B. napus or both species. Information derived from metabolite datasets can provide a blueprint for improvement of water use efficiency and drought tolerance in crops.

Reversibly oxidized cysteine sulfhydryl groups serve as redox sensors or targets of redox sensing that are important in various physiological processes. However, little is known about redox-sensitive proteins in guard cells and how they function in stomatal signaling. In this study, Brassica napus guard-cell proteins altered by redox in response to abscisic acid (ABA) or methyl jasmonate (MeJA) were identified by complementary proteomics approaches, saturation differential in-gel electrophoresis and isotope-coded affinity tagging. In total, 65 and 118 potential redox-responsive proteins were identified in ABA- and MeJA-treated guard cells, respectively. All the proteins contain at least one cysteine, and over half of them are predicted to form intra-molecular disulfide bonds. Most of the proteins fall into the functional groups of 'energy', 'stress and defense' and 'metabolism'. Based on the peptide sequences identified by mass spectrometry, 30 proteins were common to ABA- and MeJA-treated samples. A total of 44 cysteines were mapped in the identified proteins, and their levels of redox sensitivity were quantified. Two of the proteins, a sucrose non-fermenting 1-related protein kinase and an isopropylmalate dehydrogenase, were confirmed to be redox-regulated and involved in stomatal movement. This study creates an inventory of potential redox switches, and highlights a protein redox regulatory mechanism in ABA and MeJA signal transduction in guard cells.

Although the potential anticancer effect of resveratrol (RSV) on pancreatic cancer has been reported, its mechanism was not fully understood. The role of vascular endothelial growth factor B (VEGF-B) in cancer remains controversial. Herein, we aimed to examine whether the anticancer effect of RSV was related to the VEGF-B. The effect of RSV on pancreatic cancer cell line (capan-2 cells) was evaluated by CCK-8 assay, Hoechst 33342 staining, and flow cytometry. The mRNA level of VEGF-B was measured by real-time PCR. VEGF-B expression was knockdown by small interfering RNA (siRNA).The protein levels of VEGF-B, glycogen synthase kinase-3 beta (GSK-3β), and Bax were measured by Western blot. Resveratrol treatment inhibited tumor growth, induced apoptosis, and up-regulated Bax expression in capan-2 cells. The mRNA and protein levels of VEGF-B were up-regulated after RSV treatment. However, VEGF-B siRNA treatment increased the apoptotic rate, and inhibited tumor activator GSK-3β, while Bax expression was not affected. The combination of RSV and VEGF-B siRNA showed significantly higher apoptotic rate in comparison with RSV or VEGF-B siRNA mono-treatment group. Resveratrol plays dual roles in pancreatic cancer: as a tumor suppressor via the up-regulation of Bax; as a tumor activator via the up-regulation of VEGF-B; and the anticancer effect of RSV is much stronger than the cancer promotion effect. The combination of RSV with pharmacological inhibitor of VEGF-B might, therefore, be a promising modality for clinical pancreatic cancer therapy.

Individual metabolites have been implicated in abscisic acid (ABA) signaling in guard cells, but a metabolite profile of this specialized cell type is lacking. We used liquid chromatography–multiple reaction monitoring mass spectrometry for targeted analysis of 85 signaling-related metabolites in Arabidopsis thaliana guard cell protoplasts over a time course of ABA treatment. The analysis utilized ∼350 million guard cell protoplasts from ∼30,000 plants of the Arabidopsis Columbia accession (Col) wild type and the heterotrimeric G-protein α subunit mutant, gpa1, which has ABA-hyposensitive stomata. These metabolomes revealed coordinated regulation of signaling metabolites in unrelated biochemical pathways. Metabolites clustered into different temporal modules in Col versus gpa1, with fewer metabolites showing ABA-altered profiles in gpa1. Ca2+-mobilizing agents sphingosine-1-phosphate and cyclic adenosine diphosphate ribose exhibited weaker ABA-stimulated increases in gpa1. Hormone metabolites were responsive to ABA, with generally greater responsiveness in Col than in gpa1. Most hormones also showed different ABA responses in guard cell versus mesophyll cell metabolomes. These findings suggest that ABA functions upstream to regulate other hormones, and are also consistent with G proteins modulating multiple hormonal signaling pathways. In particular, indole-3-acetic acid levels declined after ABA treatment in Col but not gpa1 guard cells. Consistent with this observation, the auxin antagonist α-(phenyl ethyl-2-one)-indole-3-acetic acid enhanced ABA-regulated stomatal movement and restored partial ABA sensitivity to gpa1.

Artemisinin is widely used as an antimalarial drug around the world. Artemisinic aldehyde Δ11(13) reductase (DBR2) is a key enzyme which reduces artemisinic aldehyde to dihydroartemisinic aldehyde in the biosynthesis of artemisinin. In this study, two fragments encompassing a putative promoter of DBR2, designated as DBR2pro1 and DBR2pro2, were isolated using genomic DNA walking. The transcription start site and the putative cis-elements of each version of promoter were predicted using bioinformatic analysis. In order to study the function of the cloned promoter, Artemisia annua was transformed with β-glucuronidase (GUS) reporter gene driven by DBR2pro1 and DBR2pro2, respectively. GUS staining results demonstrated that both DBR2pro1 and DBR2pro2 were strongly expressed in glandular secretory trichomes (GSTs) of leaf primordia and flower buds, but were not obviously expressed in roots, stems, old leaves, and fully developed flowers, thus indicating that the two versions of promoter were functional and specifically expressed in GSTs.

The objective was to examine the protective effect of resveratrol (RSV) on myocardial ischemia/reperfusion (IR) injury and whether the mechanism was related to vascular endothelial growth factor B (VEGF-B) signaling pathway. Rat hearts were isolated for Langendorff perfusion test and H9c2 cells were used for in vitro assessments. RSV treatment significantly improved left ventricular function, inhibited CK-MB release, and reduced infarct size in comparison with IR group ex vivo. RSV treatment markedly decreased cell death and apoptosis of H9c2 cells during IR. We found that RSV was responsible for the up-regulation of VEGF-B mRNA and protein level, which caused the activation of Akt and the inhibition of GSK3β. Additionally, RSV prevented the generation of reactive oxygen species (ROS) by up-regulating the expression of MnSOD either in vitro or ex vivo. We also found that the inhibition of VEGF-B abolished the cardioprotective effect of RSV, increased apoptosis, and led to the down-regulation of phosphorylated Akt, GSK3β, and MnSOD in H9c2 cells. These results demonstrated that RSV was able to attenuate myocardial IR injury via promotion of VEGF-B/antioxidant signaling pathway. Therefore, the up-regulation of VEGF-B can be a promising modality for clinical myocardial IR injury therapy.

Our previous study showed that resveratrol (RSV) exhibited not only anti-tumor effect, but also had potential tumor promotion effect on pancreatic cancer (Paca) cells through up-regulation of VEGF-B. We determined whether metformin (MET) could potentiate the anti-tumor effect of RSV on PaCa in this study. Combination of RSV (100 μmol/l) and MET (20 mmol/l) significantly inhibited tumor growth and increased apoptosis of human PaCa in comparison with RSV or MET alone treatment in PaCa cell lines (Miapaca-2, Panc-1 and Capan-2). Combination of RSV (60 mg/kg, gavage) and MET (250 mg/kg, i.p.) significantly inhibited tumor growth in PaCa bearing nude mice (subcutaneous injection of 5 × 106 Miapaca-2 cells) in comparison with RSV or MET alone treatment on day 40. Combination treatment significantly decreased VEGF-B expression and inhibited activity of GSK-3β when compared to the RSV alone treatment. Up-regulated expressions of Bax, cleaved caspase-3 and down-regulated expression of Bcl-2 were observed in RSV+ MET group in comparison with RSV group either in vitro or in vivo. Inhibition of VEGF-B by VEGF-B small interfering RNA (siRNA) mimicked the effects of MET on PaCa cells. These results suggested that MET, a potential pharmacological inhibitor of VEGF-B signaling pathway, potentiated the anti-tumor effect of RSV on PaCa, and combination of MET and RSV would be a promising modality for clinical PaCa therapy.

Bioassays are commonly used to study stomatal phenotypes. There are multiple options in the choice of plant materials and species used for observation of stomatal and guard cell responses in vivo. Here, detailed procedures for bioassays of stomatal responses to abscisic acid (ABA) in Arabidopsis thaliana are described, including ABA promotion of stomatal closure, ABA inhibition of stomatal opening, and ABA promotion of reaction oxygen species (ROS) production in guard cells. We also include an example of a stomatal bioassay for the guard cell CO2 response using guard cell-enriched epidermal peels from Brassica napus. Highly pure preparations of guard cell protoplasts can be produced, which are also suitable for studies on guard cell signaling, as well as for studies on guard cell ion transport. Small-scale and large-scale guard cell protoplast preparations are commonly used for electrophysiological and -omics studies, respectively. We provide a procedure for small-scale guard cell protoplasting from A. thaliana. Additionally, a general protocol for large-scale preparation of guard cell protoplasts, with specifications for three different species, A. thaliana, B. napus, and Vicia faba is also provided.

Plants have evolved elaborate mechanisms to perceive and integrate signals from various environmental conditions. On leaf surface, stomata formed by pairs of guard cells mediate gas exchange, water transpiration as well as function in response to abiotic and biotic stresses. Stomatal closure could be induced by drought, salt, pathogen and other adverse conditions. This constitutes an instant defense response to prevent further damage to plants. Abscisic acid (ABA) is a major plant hormone involved in stress responses. Stress-activated ABA synthesis causes stomatal closure and prevents opening to reduce water loss and cell dehydration. Key regulatory receptor complex and other important components in the ABA signaling pathway have been identified. However, our knowledge of ABA signal transduction in guard cells is far from complete. Jasmonates are a group of phytohormones generally known to be important for plant defense against insects and necrotrophic pathogens. The increased levels of methyl jasmonate (MeJA) induced by herbivory and pathogen invasion show a similar effect on stomatal movement associated with ROS production as ABA. Investigation of guard cell signaling networks involving the two important phytohormones is significant and exciting. Information about protein and metabolite components and how they interact in guard cells is lacking. Here we review recent advances on hormone signaling networks in guard cells and how the networks integrate environmental signals to plant physiological output.

Stomata, microscopic pores in leaf surfaces through which water loss and carbon dioxide uptake occur, are closed in response to drought by the phytohormone abscisic acid (ABA). This process is vital for drought tolerance and has been the topic of extensive experimental investigation in the last decades. Although a core signaling chain has been elucidated consisting of ABA binding to receptors, which alleviates negative regulation by protein phosphatases 2C (PP2Cs) of the protein kinase OPEN STOMATA 1 (OST1) and ultimately results in activation of anion channels, osmotic water loss, and stomatal closure, over 70 additional components have been identified, yet their relationships with each other and the core components are poorly elucidated. We integrated and processed hundreds of disparate observations regarding ABA signal transduction responses underlying stomatal closure into a network of 84 nodes and 156 edges and, as a result, established those relationships, including identification of a 36-node, strongly connected (feedback-rich) component as well as its in- and out-components. The network’s domination by a feedback-rich component may reflect a general feature of rapid signaling events. We developed a discrete dynamic model of this network and elucidated the effects of ABA plus knockout or constitutive activity of 79 nodes on both the outcome of the system (closure) and the status of all internal nodes. The model, with more than 1024 system states, is far from fully determined by the available data, yet model results agree with existing experiments in 82 cases and disagree in only 17 cases, a validation rate of 75%. Our results reveal nodes that could be engineered to impact stomatal closure in a controlled fashion and also provide over 140 novel predictions for which experimental data are currently lacking. Noting the paucity of wet-bench data regarding combinatorial effects of ABA and internal node activation, we experimentally confirmed several predictions of the model with regard to reactive oxygen species, cytosolic Ca2+ (Ca2+c), and heterotrimeric G-protein signaling. We analyzed dynamics-determining positive and negative feedback loops, thereby elucidating the attractor (dynamic behavior) repertoire of the system and the groups of nodes that determine each attractor. Based on this analysis, we predict the likely presence of a previously unrecognized feedback mechanism dependent on Ca2+c. This mechanism would provide model agreement with 10 additional experimental observations, for a validation rate of 85%. Our research underscores the importance of feedback regulation in generating robust and adaptable biological responses. The high validation rate of our model illustrates the advantages of discrete dynamic modeling for complex, nonlinear systems common in biology., Author summary Guard cells, located in pairs on the surface of plant leaves, circumscribe microscopic pores called stomata, through which plants take up gaseous carbon dioxide that will be fixed by photosynthesis into sugars. However, plants also inevitably lose water vapor to the atmosphere through open stomata. Under drought conditions, the plant hormone abscisic acid (ABA) causes volume changes in guard cells that result in stomatal closure, thereby restricting water loss. Given the paramount importance of drought tolerance for plant survival, it is important to understand the cellular mechanisms underlying guard cell response to ABA, and over 100 studies in the literature have addressed this topic. We synthesized this information into a network that contains 84 cellular components and 156 interactions between them and then applied logic-based analyses to predict how these components coordinately transduce the ABA signal. We identified several positive feedback loops and mutual inhibition loops that can lead to sustained activity of their constituent components in the presence, or absence, of ABA. Control of these loops, for example, by other stimuli present in the natural environment, may sensitize the system to ABA. We validated some of the novel predictions from our model with new experiments.

Artemisinin is a sesquiterpenoid especially synthesized in the Chinese herbal plant, Artemisia annua, which is widely used in the treatment of malaria. Artemisinin accumulation can be enhanced by exogenous abscisic acid (ABA) treatment. However, it is not known how ABA signaling regulates artemisinin biosynthesis. A global expression profile and phylogenetic analysis as well as the dual-LUC screening revealed that a basic leucine zipper family transcription factor from A. annua (namely AabZIP1) was involved in ABA signaling to regulate artemisinin biosynthesis. AabZIP1 had a higher expression level in the inflorescences than in other tissues; ABA treatment, drought, and salt stress strongly induced the expression of AabZIP1. Yeast one-hybrid assay and electrophoretic mobility shift assay (EMSA) showed that AabZIP1 bound to the ABA-responsive elements (ABRE) in the promoter regions of the amorpha-4,11-diene synthase (ADS) gene and CYP71AV1, which are two key structural genes of the artemisinin biosynthetic pathway. A mutagenesis assay showed that the C1 domain in the N-terminus of AabZIP1 was important for its transactivation activity. Furthermore, the activation of ADS and CYP71AV1 promoters by AabZIP1 was enhanced by ABA treatment in transient dual-LUC analysis. The AabZIP1 variant with C1 domain deletion lost the ability to activate ADS and CYP71AV1 promoters regardless of ABA treatment. Notably, overexpression of AabZIP1 in A. annua resulted in significantly increased accumulation of artemisinin. Our results indicate that ABA promotes artemisinin biosynthesis, likely through 1 activation of ADS and CYP71AV1 expression by AabZIP in A. annua. Meanwhile, our findings reveal the potential value of AabZIP1 in genetic engineering of artemisinin production.

Objective: Exercise training (ET) provides a cardioprotective effect against pathological cardiac hypertrophy. Nitric oxide (NO) plays an important role in modulating cardiac hypertrophy. However, few studies explore the relationship between NO signaling and the inhibitory effect of ET on pathological cardiac remodeling. Methods: In this study, we evaluated ET effects on isoproterenol (ISO)-induced cardiac hypertrophy in female mice. Moreover, L-NAME (Nω-nitro-L-arginine methyl ester), a nonselective NO synthase (NOS) inhibitor, was used to assess the involvement of NO signaling in cardiac hypertrophy. Morphological and echocardiographic variables were assessed. Cardiac hypertrophy-related gene expression was detected by real-time PCR and the protein levels of NOS signaling molecules were determined by Western blot. Results:L-NAME treatment prevented the beneficial effects of ET against the increase in heart weight (HW)/body weight (BW), HW/tibia length and lung weight/BW and echocardiographic variables following ISO injection. Also, L-NAME co-administration reversed ET-induced inhibition of myocardial fibrosis and fetal gene reactivation in ISO-treated mice. Furthermore, L-NAME treatment prevented ET-mediated up-regulation of phosphorylated endothelial NOS and plasma NO in ISO-treated mice. Conclusions: Our findings demonstrate that L-NAME treatment could abolish ET-induced cardioprotection against pathological cardiac hypertrophy and that NOS modulation may be involved in the antihypertrophic effects induced by ET.

Islet preservation plays an important role for the success of islet transplantation. To determine the optimal method for islet preservation, we compared the outcomes of islet culture, cold preservation, and cryopreservation in this study. Isolated rat islets were divided into three groups: 37 °C group (conventional culture at 37 °C in RPMI-1640 medium), 4 °C group (cold preservation at 4 °C in University of Wisconsin (UW) solution), and −80 °C group (cryopreservation at −80 °C with dimethyl sulfoxide (DMSO)). Recovery rate, Calcein-AM/PI double staining, insulin release, mRNA level of hypoxia-inducible factor-1α (HIF-1α), and protein level of Bax in islets were examined after short-term (1 day) or long-term (7 days) preservation. After either short-term or long-term preservation, 4 °C group showed higher recovery rate of the islets number, lower percentage of PI positive area, better insulin release ability, and lower expression levels of HIF-1α and Bax in comparison to the 37 or −80 °C group. Meanwhile, islets in 37 °C group showed better function, and down-regulation of HIF-1α and Bax than those in −80 °C group on day 1; however, worse function of islets, up-regulated HIF-1α and Bax in 37 °C group were observed in comparison to −80 °C group on day 7. These results suggest that cold preservation at 4 °C in UW solution is the optimal method in comparison to the conventional culture at 37 °C or cryopreservation at −80 °C for short-term or long-term islet preservation. Furthermore, the potential mechanism may relate to, at least in part, apoptosis induced by the HIF-1α.

The phytohormone abscisic acid (ABA) plays an important role in plant development and environmental stress response. In this study, we cloned an ABA receptor orthologue, AaPYL9, from Artemisia annua L. AaPYL9 is expressed highly in leaf and flower. AaPYL9 protein can be localized in both nucleus and cytoplasm. Yeast two-hybrid assay shows AaPYL9 can specifically interact with AtABI1 but not with AtABI2, AtHAB1 or AtHAB2. ABA can enhance the interaction between AaPYL9 and AtABI1 while AaPYL9-89 Pro→Ser and AaPYL9-116 His→Ala point mutations abolishes the interaction. BiFC assay shows that AaPYL9 interacts with AtABI1 in nucleus in planta. Transgenic Arabidopsis plants over-expressing AaPYL9 are more sensitive to ABA in the seed germination and primary root growth than wild type. Consistent with this, ABA report genes have higher expression in AaPYL9 overexpressing plants compared to wild type after ABA treatment. Moreover, overexpression of AaPYL9 in A. annua increases not only drought tolerance, but also artemisinin content after ABA treatment, with significant enhancement of the expression of key genes in artemisinin biosynthesis. This study provides a way to develop A. annua with high-yielding artemisinin and high drought resistance.

Stomata on leaf epidermis formed by pairs of guard cells control CO(2) intake and water transpiration, and respond to different environmental conditions. Stress-induced stomatal closure is mediated via an intricate hormone network in guard cells. Although methyl jasmonate (MeJA) has been intensively studied for its function in plant defense, the molecular mechanisms underlying its function in stomatal movement are not fully understood. Here we report the effects of MeJA on Brassica napus stomatal movement and H(2)O(2) production. Using the isobaric tags for relative and absolute quantitation (iTRAQ) approach, we have identified 84 MeJA-responsive proteins in B. napus guard cells. Most of the genes encoding these proteins contain jasmonate-responsive elements in the promoters, indicating that they are potentially regulated at the transcriptional level. Among the identified proteins, five protein changes after MeJA treatment were validated using Western blot analysis. The identification of the MeJA-responsive proteins has revealed interesting molecular mechanisms underlying MeJA function in guard cells, which include homeostasis of H(2)O(2) production and scavenging, signaling through calcium oscillation and protein (de)phosphorylation, gene transcription, protein modification, energy balance, osmoregulation, and cell shape modulation. The knowledge of the MeJA-responsive proteins has improved our understanding of MeJA signaling in stomatal movement, and it may be applied to crop engineering for enhanced yield and stress tolerance.

Pseudomonas syringae pv. tomato strain DC3000 not only causes bacterial speck disease in Solanum lycopersicum but also on Brassica species, as well as on Arabidopsis thaliana, a genetically tractable host plant(1,2). The accumulation of reactive oxygen species (ROS) in cotyledons inoculated with DC3000 indicates a role of ROS in modulating necrotic cell death during bacterial speck disease of tomato(3). Hydrogen peroxide, a component of ROS, is produced after inoculation of tomato plants with Pseudomonas(3). Hydrogen peroxide can be detected using a histochemical stain 3'-3' diaminobenzidine (DAB)(4). DAB staining reacts with hydrogen peroxide to produce a brown stain on the leaf tissue(4). ROS has a regulatory role of the cellular redox environment, which can change the redox status of certain proteins(5). Cysteine is an important amino acid sensitive to redox changes. Under mild oxidation, reversible oxidation of cysteine sulfhydryl groups serves as redox sensors and signal transducers that regulate a variety of physiological processes(6,7). Tandem mass tag (TMT) reagents enable concurrent identification and multiplexed quantitation of proteins in different samples using tandem mass spectrometry(8,9). The cysteine-reactive TMT (cysTMT) reagents enable selective labeling and relative quantitation of cysteine-containing peptides from up to six biological samples. Each isobaric cysTMT tag has the same nominal parent mass and is composed of a sulfhydryl-reactive group, a MS-neutral spacer arm and an MS/MS reporter(10). After labeling, the samples were subject to protease digestion. The cysteine-labeled peptides were enriched using a resin containing anti-TMT antibody. During MS/MS analysis, a series of reporter ions (i.e., 126-131 Da) emerge in the low mass region, providing information on relative quantitation. The workflow is effective for reducing sample complexity, improving dynamic range and studying cysteine modifications. Here we present redox proteomic analysis of the Pst DC3000 treated tomato (Rio Grande) leaves using cysTMT technology. This high-throughput method has the potential to be applied to studying other redox-regulated physiological processes.

Guard cells, which form stomata on the leaf epidermis, play important roles in plant gas exchange and defense against pathogens. Abscisic acid (ABA) is a phytohormone that can be induced by drought and leads to stomatal closure. Guard cells have been a premier model system for studying ABA signal transduction. Despite significant progress on the identification of molecular components in the ABA signaling pathway, our knowledge of the protein components is very limited. Here, we employ a recently developed multiplexed isobaric tagging technology to identify ABA-responsive proteins in Brassica napus guard cells. A total of 431 unique proteins were identified with relative quantitative information in control and ABA-treated samples. Proteins involved in stress and defense constituted a major group among the 66 proteins with increased abundance. Thirty-eight proteins were decreased in abundance and fell into several functional groups including metabolism and protein synthesis. Many of the proteins have not been reported as being ABA responsive or involved in stomatal movement. A large percentage of the protein-coding genes contained ABA-responsive elements. This study not only established a comprehensive inventory of ABA-responsive proteins, but also identified new proteins for further investigation of their functions in guard cell ABA signaling.

Protein redox regulation is increasingly recognized as an important switch of protein activity in yeast, bacteria, mammals and plants. In this study, we identified proteins with potential thiol switches involved in jasmonate signaling, which is essential for plant defense. Methyl jasmonate (MeJA) treatment led to enhanced production of hydrogen peroxide in Arabidopsis leaves and roots, indicating in vivo oxidative stress. With monobromobimane (mBBr) labeling to capture oxidized sulfhydryl groups and 2D gel separation, a total of 35 protein spots that displayed significant redox and/or total protein expression changes were isolated. Using LC-MS/MS, the proteins in 33 spots were identified in both control and MeJA-treated samples. By comparative analysis of mBBr and SyproRuby gel images, we were able to determine many proteins that were redox responsive and proteins that displayed abundance changes in response to MeJA. Interestingly, stress and defense proteins constitute a large group that responded to MeJA. In addition, many cysteine residues involved in the disulfide dynamics were mapped based on tandem MS data. Identification of redox proteins and their cysteine residues involved in the redox regulation allows for a deeper understanding of the jasmonate signaling networks.

Extensive data have shown that exercise training can provide cardio-protection against pathological cardiac hypertrophy. However, how long the heart can retain cardio-protective phenotype after the cessation of exercise is currently unknown. In this study, we investigated the time course of the loss of cardio-protection after cessation of exercise and the signaling molecules that are responsible for the possible sustained protection. Mice were made to run on a treadmill six times a week for 4 weeks and then rested for a period of 0, 1, 2 and 4 weeks followed by isoproterenol injection for 8 days. Morphological, echocardiographic and hemodynamic changes were measured, gene reactivation was determined by real-time PCR, and the expression and phosphorylation status of several cardio-protective signaling molecules were analyzed by Western-blot. HW/BW, HW/TL and LW/BW decreased significantly in exercise training (ER) mice. The less necrosis and lower fetal gene reactivation induced by isoproterenol injection were also found in ER mice. The echocardiographic and hemodynamic changes induced by β-adrenergic overload were also attenuated in ER mice. The protective effects can be sustained for at least 2 weeks after the cessation of the training. Western-blot analysis showed that the alterations in the phosphorylation status of endothelial nitric oxide synthase (eNOS) (increase in serine 1177 and decrease in threonine 495) continued for 2 weeks after the cessation of the training whereas increases of the phosphorylation of Akt and mTOR disappeared. Further study showed that L-NG-Nitroarginine methyl ester (L-NAME) treatment abolished the cardio-protective effects of ER. Our findings demonstrate that stimulation of eNOS in mice through exercise training provides acute and sustained cardioprotection against cardiac hypertrophy.