The biological effect of endogenous sulfur dioxide in the cardiovascular system

Two-Step Sensing, Colorimetric and Ratiometric Fluorescent Probe for Rapid Detection of Bisulfite in Aqueous Solutions and in Living Cells

Bisulfite and sulfite (HSO₃ ^-/SO₃ ^2-) are not only widely used toxic chemicals but also active anions with important biological functions. Hence, the development of new detection methods for HSO₃ ^-/SO₃ ^2- is important for environmental security and human health. In this paper, we report a symmetrical hemicyanine for the detection of HSO₃ ^-/SO₃ ^2-, SHC, which is constructed with p-diphthalaldehyde with trimethylbenzoindolium via condensation. The red fluorescent probe can fast respond to HSO₃ ^-/SO₃ ^2- (<30 s) to give cyan fluorescence, and its sensing process is twice nucleophilic additions, which were observed from fluorescence response, initial ratiometric change, and subsequent turn-on increment; especially in a low-concentration level, the ratiometric fluorescence measurement can eliminate environmental interference. This probe can achieve a quantitative detection of HSO₃ ^-/SO₃ ^2- in a wide concentration range. Furthermore, the probe SHC is a mitochondria-specific probe for ratiometric fluorescent detection of HSO₃ ^-/SO₃ ^2- in living cells.

Increased Endogenous Sulfur Dioxide Involved in the Pathogenesis of Postural Tachycardia Syndrome in Children: A Case-Control Study

Background

The pathogenesis of postural tachycardia syndrome (POTS) remains unclear. This study aimed to explore the changes and significance of sulfur dioxide (SO₂) in patients with POTS.

Methods

The study included 31 children with POTS and 27 healthy children from Peking University First Hospital between December 2013 and October 2015. A detailed medical history, physical examination results, and demographic characteristics were collected. Hemodynamics was recorded and the plasma SO₂was determined.

Results

The plasma SO₂was significantly higher in POTS children compared to healthy children (64.0 ± 20.8 μmol/L vs. 27.2 ± 9.6 μmol/L, respectively, P < 0.05). The symptom scores in POTS were positively correlated with plasma SO₂levels (r = 0.398, P < 0.05). In all the study participants, the maximum heart rate (HR) was positively correlated with plasma levels of SO₂(r = 0.679, P < 0.01). The change in systolic blood pressure from the supine to upright (ΔSBP) in POTS group was smaller than that in the control group (P < 0.05). The ΔSBP was negatively correlated with baseline plasma SO₂levels in all participants (r = -0.28, P < 0.05). In the control group, ΔSBP was positively correlated with the plasma levels of SO₂(r = 0.487, P < 0.01). The change in HR from the supine to upright in POTS was obvious compared to that of the control group. The area under curve was 0.967 (95% confidence interval: 0.928-1.000), and the cutoff value of plasma SO₂ level >38.17 μmol/L yielded a sensitivity of 90.3% and a specificity of 92.6% for predicting the diagnosis of POTS.

Conclusions

Increased endogenous SO₂levels might be involved in the pathogenesis of POTS.

Esterase-sensitive sulfur dioxide prodrugs inspired by modified Julia olefination

Sulfur dioxide (SO₂) is an endogenously produced gaseous molecule, and is emerging as a potential gasotransmitter. Herein, we describe the first series of esterase-sensitive prodrugs inspired by modified Julia olefination as SO₂ donors.

Chemical trapping and characterization of small oxoacids of sulfur (SOS) generated in aqueous oxidations of H2S

Small oxoacids of sulfur (SOS) are elusive molecules like sulfenic acid, HSOH, and sulfinic acid, HS(O)OH, generated during the oxidation of hydrogen sulfide, H2S, in aqueous solution. Unlike their alkyl homologs, there is a little data on their generation and speciation during H2S oxidation. These SOS may exhibit both nucleophilic and electrophilic reactivity, which we attribute to interconversion between S(II) and S(IV) tautomers. We find that SOS may be trapped in situ by derivatization with nucleophilic and electrophilic trapping agents and then characterized by high resolution LC MS. In this report, we compare SOS formation from H2S oxidation by a variety of biologically relevant oxidants. These SOS appear relatively long lived in aqueous solution, and thus may be involved in the observed physiological effects of H2S.

A pathway-based association analysis identified FMNL1-MAP3K14 as susceptibility genes for leprosy

The nuclear transcription factor-κB (NF-κB) plays a pivotal role in controlling both innate and adaptive immunity and regulates the expressions of many immunological mediators. Abundant evidences have showed the importance of NF-κB pathway in the host immune responses against Mycobacterium leprae in the development of leprosy. However, no particular association study between leprosy and NF-κB pathway-related gene polymorphisms was reported. Here, we performed a large-scale and two-stage candidate association study to investigate the association between 94 NF-κB pathway-related genes and leprosy. Our results showed that rs58744688 was significantly associated with leprosy (P = 7.57 × 10-7 , OR = 1.12) by combining the previous genomewide association data sets and four independent validation sample series, consisting of a total of 4631 leprosy cases and 6413 healthy controls. This founding implicated that MAP3K14 and FMNL1 were susceptibility genes for leprosy, which suggested the involvement of macrophage targeting and NF-κB pathway in the development of leprosy.

A rapid cell-permeating turn-on probe for sensitive and selective detection of sulfite in living cells

A rapid cell-permeating probeNJUXJ-1was introduced for sensitive and selective detection of sulfite in living cells.

H2S and polysulfide metabolism: Conventional and unconventional pathways

It is now well established that hydrogen sulfide (H₂S) is an effector of a wide variety of physiological processes. It is also clear that many of the effects of H₂S are mediated through reactions with cysteine sulfur on regulatory proteins and most of these are not mediated directly by H₂S but require prior oxidation of H₂S and the formation of per- and polysulfides (H₂S_n, n = 2-8). Attendant with understanding the regulatory functions of H₂S and H₂S_n is an appreciation of the mechanisms that control, i.e., both increase and decrease, their production and catabolism. Although a number of standard "conventional" pathways have been described and well characterized, novel "unconventional" pathways are continuously being identified. This review summarizes our current knowledge of both the conventional and unconventional.

Gaseous signalling molecule SO2 via Hippo‑MST pathway to improve myocardial fibrosis of diabetic rats

Recent studies have indicated the existence of an endogenous sulfur dioxide (SO2)‑generating system in the cardiovascular system. The present study aimed to discuss the function and regulatory mechanism of gaseous signal molecule SO2 in inhibiting apoptosis and endoplasmic reticulum stress (ERS) via the Hippo‑MST signaling pathway to improve myocardial fibrosis of diabetic rats. A total of 40 male Sprague‑Dawley rats were randomly divided into four groups (10 rats per group): Normal control group (control group), diabetic rats group [streptozotocin (STZ) group], SO2 intervention group (STZ+SO2 group) and diabetes mellitus rats treated with L‑Aspartic acid β‑hydroxamate (HDX) group (HDX group). Diabetic rats models were established by intra‑peritoneal injection of STZ (40 mg/kg) Following model establishment, intra‑peritoneal injection of Na2SO3/NaHSO3 solution (0.54 mmol/kg) was administered in the STZ+SO2 group, and HDX solution (25 mg/kg/week) was administered in the HDX group. A total of 4 weeks later, echocardiography was performed to evaluate rats' cardiac function; Masson staining, terminal deoxynucleotidyl transferase dUTP nick end labeling staining and transmission electron microscopy examinations were performed to observe myocardial morphological changes. ELISA was employed to determine the SO2 content. Western blot analysis was performed to detect the expression of proteins associated with apoptosis, ERS and the Hippo‑MST signalling pathway. Compared with the control group, the STZ group and HDX group had a disordered arrangement of myocardial cells with apparent myocardial fibrosis, and echocardiography indicated that the cardiac function was lowered, there was an obvious increase of apoptosis in myocardial tissue, the expression levels of apoptosis‑associated protein B‑cell lymphoma associated protein X, caspase‑3 and caspase‑9 were upregulated, and Bcl‑2 expression was downregulated. The expression of ERS and Hippo‑MST pathway‑associated proteins, including CHOP, GRP94, MST1 and MST2, were significantly upregulated. By contrast, these above‑mentioned changes were reversed by SO2 treatment. Compared with STZ group, the HDX group had a further increase of myocardial fibrosis and apoptosis, while there were no statistically significant differences in the expression of Bax/Bcl‑2, caspase‑3, caspase‑9 and ERS and Hippo‑MST pathway‑associated proteins. The results of the present study demonstrated that the gaseous signal molecule SO2 can effectively improve the myocardial fibrosis of diabetic rats, and its mechanism may be associated with reduced apoptosis and ERS by downregulated Hippo‑MST pathway.

A novel colorimetric and ratiometric fluorescent probe for visualizing SO2 derivatives in environment and living cells

Monitoring sulfur dioxide (SO₂) derivatives in environment is of great significance due to their harmful effects to the environment and human health. In this study, a fluorescent probe (CZBT) for SO₂ derivatives was prepared from 9-ethyl-9H-carbazole-3,6-dicarboxaldehyde and 2-methyl-benzothiazolium, which displayed a noticeable color change from yellow to colorless along with a remarkable fluorescence change from yellow to blue in response to HSO₃^-. The probe could quantitatively determine the concentration of HSO₃^- with excellent selectivity, high sensitivity and low limit of detection. ¹H NMR and HR-MS spectra demonstrated that a selective 1, 4-nucleophilic addition occurred on the bridge double bond in CZBT. The probe was successfully used to determine the SO₂ derivatives in several real water samples with good recovery. Furthermore, the probe was employed for monitoring the level of intracellular HSO₃^- in HeLa (human cervical cancer) cells by fluorescence imaging. These results indicated that CZBT has a good capability for monitoring SO₂ derivatives in environment and living cells.

Click and Release: SO2 Prodrugs with Tunable Release Rates

Employing an intramolecular cycloaddition reaction, we have developed a series of SO₂ prodrugs with tunable release rates with half-lives ranging from minutes to days.

Sulfur Dioxide Protects Against Collagen Accumulation in Pulmonary Artery in Association With Downregulation of the Transforming Growth Factor β1/Smad Pathway in Pulmonary Hypertensive Rats

BACKGROUND

We aimed to explore the role of endogenous sulfur dioxide (SO2) in pulmonary vascular collagen remodeling induced by monocrotaline and its mechanisms.

METHODS AND RESULTS

A rat model of monocrotaline-induced pulmonary vascular collagen remodeling was developed and administered with l-aspartate-β-hydroxamate or SO2 donor. The morphology of small pulmonary arteries and collagen metabolism were examined. Cultured pulmonary arterial fibroblasts stimulated by transforming growth factor β1 (TGF-β1) were used to explore the mechanism. The results showed that in monocrotaline-treated rats, mean pulmonary artery pressure increased markedly, small pulmonary arterial remodeling developed, and collagen deposition in lung tissue and pulmonary arteries increased significantly in association with elevated SO2 content, aspartate aminotransferase (AAT) activity, and expression of AAT1 compared with control rats. Interestingly, l-aspartate-β-hydroxamate, an inhibitor of SO2 generation, further aggravated pulmonary vascular collagen remodeling in monocrotaline-treated rats, and inhibition of SO2 in pulmonary artery smooth muscle cells activated collagen accumulation in pulmonary arterial fibroblasts. SO2 donor, however, alleviated pulmonary vascular collagen remodeling with inhibited collagen synthesis, augmented collagen degradation, and decreased TGF-β1 expression of pulmonary arteries. Mechanistically, overexpression of AAT1, a key enzyme of SO2 production, prevented the activation of the TGF-β/type I TGF-β receptor/Smad2/3 signaling pathway and abnormal collagen synthesis in pulmonary arterial fibroblasts. In contrast, knockdown of AAT1 exacerbated Smad2/3 phosphorylation and deposition of collagen types I and III in TGF-β1-treated pulmonary arterial fibroblasts.

CONCLUSIONS

Endogenous SO2 plays a protective role in pulmonary artery collagen accumulation induced by monocrotaline via inhibition of the TGF-β/type I TGF-β receptor/Smad2/3 pathway.

A ratiometric fluorescence probe for selective detection of sulfite and its application in realistic samples

A new fluorescent probe 7-(diethylamino)-3-((1e,3e)-5-oxo-5-phenylpenta-1,3-dien-1-yl)-2H-chromen-2-one (SPH), based on Michael addition mechanism, was designed and synthesized for selective detection of sulfite. The probe was constructed by incorporating an α,β-unsaturated ketone conjugated with a C˭C bond into the coumarin fluorophore as a specifical reaction site for sulfite utilizing its nucleophilic property. The extra conjugated C˭C bond induced obvious red-shifts in both absorption and emission maxima, and remarkably promoted the nucleophilic addition rate. Once treated with sulfite, the solution's color changed from orange to yellow companied with a strong blue-green fluorescence. The ratio of fluorescence intensity at 488nm and 630nm (I₄₈₈/I₆₃₀) was linear with sulfite concentration over the range of 0-80μM with a detection limit of 0.23μM. High selectivity and good competition of the probe toward sulfite over other anions and thiols enable us to monitor sulfite levels in realistic samples as well as in living HeLa cells.

A two-photon fluorescent turn-on probe for imaging of SO2 derivatives in living cells and tissues

SO2 and its derivatives (bisulfite/sulfite) play crucial roles in several physiological processes. Therefore, development of reliable analytical methods for monitoring SO2 and its derivatives in biological systems is very significant. In this paper, a FRET-based two-photon fluorescent turn-on probe, A-HCy, was proposed for specific detection of SO2 derivatives through the bisulfite/sulfite-promoted Michael addition reaction. In this FRET system, an acedan (2-acetyl-6-dialkylaminonaphthalene) moiety was selected as a two-photon donor and a hemicyanine derivative served as both the quencher and the recognition unit for bisulfite/sulfite. A-HCy exhibited excellent selectivity and rapid response to HSO3(-) with a detection limit of 0.24 μM. More importantly, probe A-HCy was first successfully applied in two-photon fluorescence imaging of biological SO2 derivatives in living cells and tissues, suggesting its great potential for practical application in biological systems.

Overview of Antagonists Used for Determining the Mechanisms of Action Employed by Potential Vasodilators with Their Suggested Signaling Pathways

This paper is a review on the types of antagonists and the signaling mechanism pathways that have been used to determine the mechanisms of action employed for vasodilation by test compounds. Thus, we exhaustively reviewed and analyzed reports related to this topic published in PubMed between the years of 2010 till 2015. The aim of this paperis to suggest the most appropriate type of antagonists that correspond to receptors that would be involved during the mechanistic studies, as well as the latest signaling pathways trends that are being studied in order to determine the route(s) that atest compound employs for inducing vasodilation. The methods to perform the mechanism studies were included. Fundamentally, the affinity, specificity and selectivity of the antagonists to their receptors or enzymes were clearly elaborated as well as the solubility and reversibility. All the signaling pathways on the mechanisms of action involved in the vascular tone regulation have been well described in previous review articles. However, the most appropriate antagonists that should be utilized have never been suggested and elaborated before, hence the reason for this review.

Endogenous Sulfur Dioxide Inhibits Vascular Calcification in Association with the TGF-β/Smad Signaling Pathway

The study was designed to investigate whether endogenous sulfur dioxide (SO₂) plays a role in vascular calcification (VC) in rats and its possible mechanisms. In vivo medial vascular calcification was induced in rats by vitamin D3 and nicotine for four weeks. In vitro calcification of cultured A7r5 vascular smooth muscle cells (VSMCs) was induced by calcifying media containing 5 mmol/L CaCl₂. Aortic smooth muscle (SM) α-actin, runt-related transcription factor 2 (Runx2), transforming growth factor-β (TGF-β) and Smad expression was measured. VC rats showed dispersed calcified nodules among the elastic fibers in calcified aorta with increased aortic calcium content and alkaline phosphatase (ALP) activity. SM α-actin was markedly decreased, but the osteochondrogenic marker Runx2 concomitantly increased and TGF-β/Smad signaling was activated, in association with the downregulated SO₂/aspartate aminotransferase (AAT) pathway. However, SO₂ supplementation successfully ameliorated vascular calcification, and increased SM α-actin expression, but inhibited Runx2 and TGF-β/Smad expression. In calcified A7r5 VSMCs, the endogenous SO₂/AAT pathway was significantly downregulated. SO₂ treatment reduced the calcium deposits, calcium content, ALP activity and Runx2 expression and downregulated the TGF-β/Smad pathway in A7r5 cells but increased SM α-actin expression. In brief, SO₂ significantly ameliorated vascular calcification in association with downregulation of the TGF-β/Smad pathway.

A novel carbazole-based mitochondria-targeted ratiometric fluorescent probe for bisulfite in living cells

A novel carbazole–indolium based mitochondria-targeted ratiometric fluorescent probe was developed, which could selectively respond to bisulfite among other sulfur-containing species in living cells.

A novel rosamine-based fluorescent probe for bisulfite in aqueous solution

A new rosamine-based fluorescent chemodosimeter has been developed for highly sensitive and selective detection of bisulfite in aqueous solution.

Endogenous Sulfur Dioxide: A New Member of Gasotransmitter Family in the Cardiovascular System

Sulfur dioxide (SO2) was previously regarded as a toxic gas in atmospheric pollutants. But it has been found to be endogenously generated from metabolism of sulfur-containing amino acids in mammals through transamination by aspartate aminotransferase (AAT). SO2 could be produced in cardiovascular tissues catalyzed by its synthase AAT. In recent years, studies revealed that SO2 had physiological effects on the cardiovascular system, including vasorelaxation and cardiac function regulation. In addition, the pathophysiological effects of SO2 were also determined. For example, SO2 ameliorated systemic hypertension and pulmonary hypertension, prevented the development of atherosclerosis, and protected against myocardial ischemia-reperfusion (I/R) injury and isoproterenol-induced myocardial injury. These findings suggested that endogenous SO2 was a novel gasotransmitter in the cardiovascular system and provided a new therapy target for cardiovascular diseases.

A mitochondria-targeted ratiometric fluorescent probe for rapid, sensitive and specific detection of biological SO2 derivatives in living cells

In this study, we report a ratiometric fluorescent probe (CZBI) for sulfur dioxide (SO2) derivatives based on the conjugate of carbazole and benzo[e]indolium, which displays colorimetric and ratiometric fluorescence dual response to HSO3(-). The probe can quantitatively detect HSO3(-) with high specificity, fast response (within 40s) as well as low detection limit (10nM). A 1,4-nucleophilic addition reaction was proposed for the sensing mechanism of this probe, which was confirmed by (1)H NMR and HR-MS spectra. Fluorescence co-localization studies demonstrated that CZBI was a specific mitochondria-targeted fluorescent probe for SO2 derivatives with excellent cell membrane permeability. Furthermore, fluorescence imaging of HeLa cells indicated that CZBI could be used for monitoring the intrinsically generated intracellular SO2 derivatives in living cells by ratiometric fluorescence imaging. Thus, CZBI has a great potential application for exploring the role played by SO2 derivatives in biology.

Signal pathways involved in the biological effects of sulfur dioxide

Gasotransmitters, such as nitric oxide, carbon monoxide and hydrogen sulfide, play important roles in life and have attracted great interest in scientists. In recent years, sulfur dioxide (SO2) has also been found to play important roles in mammals. The redox pathway is involved in the biological effects of SO2, such as the protective effect on myocardial ischemia reperfusion, myocardial injury, pulmonary hypertension and atherosclerosis. Ion channels, such as L-type calcium and adenosine triphosphate-sensitive potassium channels, as well as 3'-5'-cyclic guanosine monophosphate and 3'-5'-cyclic adenosine monophosphate pathways are also involved in the vasorelaxant effect of SO2. The mitogen-activated protein kinase pathway plays roles in vascular remodeling during pulmonary hypertension and vascular smooth muscle cell proliferation. Understanding these signaling mechanisms would help to clarify the pathophysiological effect and therapeutic potential of SO2.

Endogeous sulfur dioxide protects against oleic acid-induced acute lung injury in association with inhibition of oxidative stress in rats

The role of endogenous sulfur dioxide (SO2), an efficient gasotransmitter maintaining homeostasis, in the development of acute lung injury (ALI) remains unidentified. We aimed to investigate the role of endogenous SO2 in the pathogenesis of ALI. An oleic acid (OA)-induced ALI rat model was established. Endogenous SO2 levels, lung injury, oxidative stress markers and apoptosis were examined. OA-induced ALI rats showed a markedly downregulated endogenous SO2/aspartate aminotransferase 1 (AAT1)/AAT2 pathway and severe lung injury. Chemical colorimetry assays demonstrated upregulated reactive oxygen species generation and downregulated antioxidant capacity in OA-induced ALI rats. However, SO2 increased endogenous SO2 levels, protected against oxidative stress and alleviated ALI. Moreover, compared with OA-treated cells, in human alveolar epithelial cells SO2 downregulated O2(-) and OH(-) generation. In contrast, L-aspartic acid-β-hydroxamate (HDX, Sigma-Aldrich Corporation), an inhibitor of endogenous SO2 generating enzyme, promoted free radical generation, upregulated poly (ADP-ribose) polymerase expression, activated caspase-3, as well as promoted cell apoptosis. Importantly, apoptosis could be inhibited by the free radical scavengers glutathione (GSH) and N-acetyl-L-cysteine (NAC). The results suggest that SO2/AAT1/AAT2 pathway might protect against the development of OA-induced ALI by inhibiting oxidative stress.

A ratiometric fluorescent probe for rapid, sensitive and selective detection of sulfur dioxide with large Stokes shifts by single wavelength excitation

A ratiometric fluorescent probe was developed for rapid, sensitive and selective detection of SO₃²⁻ with large Stokes shifts. Imaging intracellular SO₃²⁻ was successfully demonstrated in living HNE-2 cells.

A real-time colorimetric and ratiometric fluorescent probe for rapid detection of SO2 derivatives in living cells based on a near-infrared benzopyrylium dye

Near-infrared benzopyrylium dye was employed as a fast-responding ratiometric fluorescent probe for sensitive and selective detection of SO₂ derivatives in 100% aqueous solution as well as in living cells.

Selective, highly sensitive fluorescent probe for the detection of sulfur dioxide derivatives in aqueous and biological environments

On the basis of a unique nucleophilic addition reaction, a novel water-soluble broadly emitting (500-700 nm) fluorescent Probe 1 was developed for the rapid detection of SO2 derivatives in aqueous media. The positively-charged benzopyrylium moiety in Probe 1 provides both excellent water solubility, making this probe applicable in 100% aqueous environments, and the ability to function as a fluorescence quencher of the coumarin moiety. Probe 1 generates a nearly instantaneous strong fluorescence signal in response to SO2 derivatives having an 8.3 nM detection limit for bisufite. The resulting Probe 1-sulfite adduct emits in the green/red spectral region (λ(max) = 585 nm) with a large Stokes shift (139 nm). The probe exhibits excellent selectivity toward SO2 derivatives over other potential interfering agents including reactive sulfur-containing species. Importantly, we demonstrate that Probe 1 can be used for the real-time sensing and bioimaging of SO2 derivatives in living cells.

The effects of α-pinene versus toluene-derived secondary organic aerosol exposure on the expression of markers associated with vascular disease

To investigate the toxicological effects of biogenic- versus anthropogenic-source secondary organic aerosol (SOA) on the cardiovascular system, the Secondary Particulate Health Effects Research program irradiation chamber was used to expose atherosclerotic apolipoprotein E null (Apo E-/-) mice to SOA from the oxidation of either α-pinene or toluene for 7 days. SOA atmospheres were produced to yield 250-300 μg/m(3) of particulate matter and ratios of 10:1:1 α-pinene:nitrogen oxide (NOx):ammonia (NH3); 10:1:1:1 α-pinene:NOx:NH3:sulfur dioxide (SO2) or 10:1:1 toluene:NOx:NH3; and 10:1:1:1 toluene:NOx:NH3:SO2. Resulting effects on the cardiovascular system were assessed by measurement of vascular lipid peroxidation (thiobarbituric acid reactive substance (TBARS)), as well as quantification of heme-oxygenase (HO)-1, endothelin (ET)-1, and matrix metalloproteinase (MMP)-9 mRNA expression for comparison to previous program exposure results. Consistent with similar previous studies, vascular TBARS were not increased significantly with any acute SOA exposure. However, vascular HO-1, MMP-9, and ET-1 observed in Apo E-/- mice exposed to α-pinene + NOx + NH3 + SO2 increased statistically, while α-pinene + NOx + NH3 exposure to either toluene + NOx + NH3 or toluene +NOx + NH3 + SO2 resulted in a decreased expression of these vascular factors. Such findings suggest that the specific chemistry created by the presence or absence of acidic components may be important in SOA-mediated toxicity in the cardiovascular system and/or progression of cardiovascular disease.

Dispersible and discrete metalloporphyrin-based CMP nanoparticles enabling colorimetric detection and quantitation of gaseous SO2

Metalloporphyrin-based CMP nanoparticles synthesized by the oxidative dimerization of terminal alkynes in the toluene-in-water miniemulsion possess native porosity, outstanding solution processability and uniform nanosized distribution. Also, they exhibit the sensitive color-switching ability for quantitative assay of gaseous SO2 by the noncovalent complex-displacement reaction at liquid-solid or gas-solid interfaces.

Air particulate matter and cardiovascular disease: a narrative review

Consistent evidences from both epidemiological and experimental studies have demonstrated that short- and long-term exposure to particulate matter (PM), in particular to the finest particles (i.e. airborne PM with aerodynamic diameter less than 2.5 μm, PM2.5), is associated with cardiovascular morbidity and mortality. PM concentration has been linked with several clinical manifestations of cardiovascular diseases (CVD), including myocardial infarction, stroke, heart failure, arrhythmias, and venous thromboembolism. Noteworthy, some groups of subjects, like elderly, diabetics, or those with known coronary artery disease, appear specifically susceptible to the harmful effects triggered by PM exposure. Although the PM-related risk for a single individual appears relatively low, the PM-related population attributable risk is impressive. Recent studies indicate that the PM-CVD relationship is likely more complex than a mere quantitative association between overall PM concentration and disease risk. Indeed, the biological effects of PM may vary in function of both the aerodynamic diameter and the chemical composition. Moreover, it has been shown that the influence of air pollution on health is not limited to PM. Indeed, other gaseous pollutants may play an independent role in CVD, suggesting the need to develop multi-pollutant preventive approaches. Causality has been recently strongly supported by observations showing reduced CVD mortality after coordinated community policies resulting in lowering PM exposure at population level. An in-depth knowledge on the heterogeneous sources, chemical compounds, and biological effects of PM may help to propose more accurate and clinically effective recommendations for this important and modifiable factor contributing to CVD burden.

Identification of chemical components of combustion emissions that affect pro-atherosclerotic vascular responses in mice

Combustion emissions cause pro-atherosclerotic responses in apolipoprotein E-deficient (ApoE/⁻) mice, but the causal components of these complex mixtures are unresolved. In studies previously reported, ApoE⁻/⁻ mice were exposed by inhalation 6 h/day for 50 consecutive days to multiple dilutions of diesel or gasoline exhaust, wood smoke, or simulated "downwind" coal emissions. In this study, the analysis of the combined four-study database using the Multiple Additive Regression Trees (MART) data mining approach to determine putative causal exposure components regardless of combustion source is reported. Over 700 physical-chemical components were grouped into 45 predictor variables. Response variables measured in aorta included endothelin-1, vascular endothelin growth factor, three matrix metalloproteinases (3, 7, 9), metalloproteinase inhibitor 2, heme-oxygenase-1, and thiobarbituric acid reactive substances. Two or three predictors typically explained most of the variation in response among the experimental groups. Overall, sulfur dioxide, ammonia, nitrogen oxides, and carbon monoxide were most highly predictive of responses, although their rankings differed among the responses. Consistent with the earlier finding that filtration of particles had little effect on responses, particulate components ranked third to seventh in predictive importance for the eight response variables. MART proved useful for identifying putative causal components, although the small number of pollution mixtures (4) can provide only suggestive evidence of causality. The potential independent causal contributions of these gases to the vascular responses, as well as possible interactions among them and other components of complex pollutant mixtures, warrant further evaluation.