Influence of Inorganic Anions on the Chemical Stability of Molybdenum Disulfide Nanosheets in the Aqueous Environment.

Chemical stability is closely associated with the transformations and bioavailabilities of engineered nanomaterials and is a key factor that governs broader and long-term application. With the growing utilization of molybdenum disulfide (MoS2) nanosheets in water treatment and purification processes, it is crucial to evaluate the stability of MoS2 nanosheets in aquatic environments. Nonetheless, the effects of anionic species on MoS2 remain largely unexplored. Herein, the stability of chemically exfoliated MoS2 nanosheets (ceMoS2) was assessed in the presence of inorganic anions. The results showed that the chemical stability of ceMoS2 was regulated by the nucleophilicities and the resultant charging effects of the anions in aquatic systems. The anions promote the dissolution of ceMoS2 by triggering a shift in the chemical potential of the ceMoS2 surface as a function of the anion nucleophilicity (i.e., charging effect). Fast charging with HCO3- and HPO42-/H2PO4- was validated by a phase transition from 1T to 2H and the emergence of MoV, and it promoted oxidative dissolution of the ceMoS2. Additionally, under sunlight, ceMoS2 dissolution was accelerated by NO3-. These findings provide insight into the ion-induced fate of ceMoS2 and the durability and risks of MoS2 nanosheets in environmental applications.

How should anti-hypertensive medications be adjusted before screening for primary aldosteronism?

Anti-hypertensive medications may affect plasma renin activity and/or plasma aldosterone concentration, misleading the interpretation of the aldosterone-to-renin ratio when screening for primary aldosteronism. The Task Force of Taiwan PA recommends that, when necessary, using α-adrenergic receptor blocking agents, centrally acting α-adrenergic agonists, and/or non-dihydropyridine calcium channel blockers should be considered to control blood pressure before screening for PA. We recommend temporarily holding ß-adrenergic receptor blocking agents, mineralocorticoid receptor antagonists, dihydropyridine calcium channel blockers, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and all diuretics before screening for PA. Further large-scale randomized controlled studies are required to confirm the recommendations.

Humic acid changes effect of naturally occurring oxidants on the environmental transformation of molybdenum disulfide nanosheets.

2H-phase molybdenum disulfide (2H-MoS2) has been considered to be a chemically stable two-dimensional (2D) nanomaterial. Nonetheless, the persistence of 2H-MoS2 in the presence of environmental redox-active matrices, such as naturally occurring oxidants (e.g., manganese dioxide (MnO2)) and natural organic matter (NOM), remains largely unknown. Herein, we examined the interplay between 2H-MoS2, MnO2 (a common natural oxidant), and NOM species (i.e., Aldrich humic acid (ALHA) and Suwannee River natural organic matter (SRNOM)). The results show that MnO2 accelerates the oxidative dissolution of 2H-MoS2, regardless of the presence of dissolved oxygen. The effect of NOM on the MnO2-induced fate of 2H-MoS2 was found to depend on its affinity for 2H-MoS2 and the functionality of NOM. ALHA preferentially adsorbed on hydrophobic 2H-MoS2 nanosheets due to the enrichment of reductive polycyclic aromatics and polyphenolic constituents. The preferential ALHA adsorption counteracted the MnO2-triggered oxidative transformation of 2H-MoS2, as revealed by the cathodic response of 2H-MoS2 (i.e., decreased the open circuit potential by 0.0338 V) and the emergence of reductive Mo‒C bonds at 228.8 and 231.9 eV upon the addition of ALHA. This work evaluated the persistence of 2H-MoS2, illustrating its susceptibility to decomposition by naturally occurring oxidants and the influence of NOM on it. These findings are crucial for revealing the fate and transport of MoS2 in aquatic environments and provide guidelines for related applications in natural or engineered systems for MoS2 and potentially other 2D materials.

Ketogenic Diet Regulates Cardiac Remodeling and Calcium Homeostasis in Diabetic Rat Cardiomyopathy.

A ketogenic diet (KD) might alleviate patients with diabetic cardiomyopathy. However, the underlying mechanism remains unclear. Myocardial function and arrhythmogenesis are closely linked to calcium (Ca2+) homeostasis. We investigated the effects of a KD on Ca2+ homeostasis and electrophysiology in diabetic cardiomyopathy. Male Wistar rats were created to have diabetes mellitus (DM) using streptozotocin (65 mg/kg, intraperitoneally), and subsequently treated for 6 weeks with either a normal diet (ND) or a KD. Our electrophysiological and Western blot analyses assessed myocardial Ca2+ homeostasis in ventricular preparations in vivo. Unlike those on the KD, DM rats treated with an ND exhibited a prolonged QTc interval and action potential duration. Compared to the control and DM rats on the KD, DM rats treated with an ND also showed lower intracellular Ca2+ transients, sarcoplasmic reticular Ca2+ content, sodium (Na+)-Ca2+ exchanger currents (reverse mode), L-type Ca2+ contents, sarcoplasmic reticulum ATPase contents, Cav1.2 contents. Furthermore, these rats exhibited elevated ratios of phosphorylated to total proteins across multiple Ca2+ handling proteins, including ryanodine receptor 2 (RyR2) at serine 2808, phospholamban (PLB)-Ser16, and calmodulin-dependent protein kinase II (CaMKII). Additionally, DM rats treated with an ND demonstrated a higher frequency and incidence of Ca2+ leak, cytosolic reactive oxygen species, Na+/hydrogen-exchanger currents, and late Na+ currents than the control and DM rats on the KD. KD treatment may attenuate the effects of DM-dysregulated Na+ and Ca2+ homeostasis, contributing to its cardioprotection in DM.

Effect of antidiabetic drugs on the risk of atrial fibrillation: mechanistic insights from clinical evidence and translational studies.

Diabetes mellitus (DM) is an independent risk factor for atrial fibrillation (AF), which is the most common sustained arrhythmia and is associated with substantial morbidity and mortality. Advanced glycation end product and its receptor activation, cardiac energy dysmetabolism, structural and electrical remodeling, and autonomic dysfunction are implicated in AF pathophysiology in diabetic hearts. Antidiabetic drugs have been demonstrated to possess therapeutic potential for AF. However, clinical investigations of AF in patients with DM have been scant and inconclusive. This article provides a comprehensive review of research findings on the association between DM and AF and critically analyzes the effect of different pharmacological classes of antidiabetic drugs on AF.

The role of transformation in the risks of chemically exfoliated molybdenum disulfide nanosheets to the aquatic environment.

While the effects of environmental factors (e.g., coexisting organic macromolecules and solar irradiation) on the phase transformation and oxidative dissolution of chemically exfoliated molybdenum nanosheets (ceMoS2) have been recognized, the effects of environmental processes on the subsequent biological impacts of ceMoS2 are still poorly understood. In this study, the bioavailability and transitions in chemical speciation occurring during the aging process are demonstrated to be key factors causing ceMoS2 to affect aquatic organisms. The lower survival rate of embryonic zebrafish with aged (i.e., sunlight-irradiated and dark-ambient-aged) ceMoS2, compared to that with freshly prepared ceMoS2, was due to the release of ionic aging products (mainly acidic Mo species) throughout the oxidative dissolution of ceMoS2. The released soluble molybdenum interacted with natural organic matter (NOM) depending on their functionality, and this attenuated the toxicity caused by ceMoS2 to different degrees. Toxicity triggered by aged ceMoS2 under both dark and irradiated conditions was significantly reduced by Suwannee River NOM due to the formation of complexes with ionic Mo species, which was established by Mo K-edge X-ray absorption spectroscopy. The findings provide useful insights for comprehending the impacts of ceMoS2 on aquatic organisms and guidance for the prevention measures necessary in the applications of MoS2 nanosheets.

Fibroblast Growth Factor 23 Stimulates Cardiac Fibroblast Activity through Phospholipase C-Mediated Calcium Signaling.

Fibroblast growth factor (FGF)-23 induces hypertrophy and calcium (Ca2+) dysregulation in cardiomyocytes, leading to cardiac arrhythmia and heart failure. However, knowledge regarding the effects of FGF-23 on cardiac fibrogenesis remains limited. This study investigated whether FGF-23 modulates cardiac fibroblast activity and explored its underlying mechanisms. We performed MTS analysis, 5-ethynyl-2'-deoxyuridine assay, and wound-healing assay in cultured human atrial fibroblasts without and with FGF-23 (1, 5 and 25 ng/mL for 48 h) to analyze cell proliferation and migration. We found that FGF-23 (25 ng/mL, but not 1 or 5 ng/mL) increased proliferative and migratory abilities of human atrial fibroblasts. Compared to control cells, FGF-23 (25 ng/mL)-treated fibroblasts had a significantly higher Ca2+ entry and intracellular inositol 1,4,5-trisphosphate (IP3) level (assessed by fura-2 ratiometric Ca2+ imaging and enzyme-linked immunosorbent assay). Western blot analysis showed that FGF-23 (25 ng/mL)-treated cardiac fibroblasts had higher expression levels of calcium release-activated calcium channel protein 1 (Orai1) and transient receptor potential canonical (TRPC) 1 channel, but similar expression levels of α-smooth muscle actin, collagen type IA1, collagen type Ⅲ, stromal interaction molecule 1, TRPC 3, TRPC6 and phosphorylated-calcium/calmodulin-dependent protein kinase II when compared with control fibroblasts. In the presence of ethylene glycol tetra-acetic acid (a free Ca2+ chelator, 1 mM) or U73122 (an inhibitor of phospholipase C, 1 µM), control and FGF-23-treated fibroblasts exhibited similar proliferative and migratory abilities. Moreover, polymerase chain reaction analysis revealed that atrial fibroblasts abundantly expressed FGF receptor 1 but lacked expressions of FGF receptors 2-4. FGF-23 significantly increased the phosphorylation of FGF receptor 1. Treatment with PD166866 (an antagonist of FGF receptor 1, 1 µM) attenuated the effects of FGF-23 on cardiac fibroblast activity. In conclusion, FGF-23 may activate FGF receptor 1 and subsequently phospholipase C/IP3 signaling pathway, leading to an upregulation of Orai1 and/or TRPC1-mediated Ca2+ entry and thus enhancing human atrial fibroblast activity.

Empagliflozin and Liraglutide Differentially Modulate Cardiac Metabolism in Diabetic Cardiomyopathy in Rats.

Glucagon-like peptide 1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) are antihyperglycemic agents with cardioprotective properties against diabetic cardiomyopathy (DCM). However, the distinctive mechanisms underlying GLP-1RAs and SGLT2is in DCM are not fully elucidated. The purpose of this study was to investigate the impacts of GLP1RAs and/or SGLT2is on myocardial energy metabolism, cardiac function, and apoptosis signaling in DCM. Biochemistry and echocardiograms were studied before and after treatment with empagliflozin (10 mg/kg/day, oral gavage), and/or liraglutide (200 µg/kg every 12 h, subcutaneously) for 4 weeks in male Wistar rats with streptozotocin (65 mg/kg intraperitoneally)-induced diabetes. Cardiac fibrosis, apoptosis, and protein expression of metabolic and inflammatory signaling molecules were evaluated by histopathology and Western blotting in ventricular cardiomyocytes of different groups. Empagliflozin and liraglutide normalized myocardial dysfunction in diabetic rats. Upregulation of phosphorylated-acetyl coenzyme A carboxylase, carnitine palmitoyltransferase 1ß, cluster of differentiation 36, and peroxisome proliferator-activated receptor-gamma coactivator, and downregulation of glucose transporter 4, the ratio of phosphorylated adenosine monophosphate-activated protein kinase α2 to adenosine monophosphate-activated protein kinase α2, and the ratio of phosphorylated protein kinase B to protein kinase B in diabetic cardiomyocytes were restored by treatment with empagliflozin or liraglutide. Nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3, interleukin-1ß, tumor necrosis factor-α, and cleaved caspase-1 were significantly downregulated in empagliflozin-treated and liraglutide-treated diabetic rats. Both empagliflozin-treated and liraglutide-treated diabetic rats exhibited attenuated myocardial fibrosis and apoptosis. Empagliflozin modulated fatty acid and glucose metabolism, while liraglutide regulated inflammation and apoptosis in DCM. The better effects of combined treatment with GLP-1RAs and SGLT2is may lead to a potential strategy targeting DCM.

Therapeutic potential of vitamin D in AGE/RAGE-related cardiovascular diseases.

Cardiovascular diseases (CVDs) are among the leading threats to human health. The advanced glycation end product (AGE) and receptor for AGE (RAGE) signaling pathway regulates the pathogenesis of CVDs, through its effects on arterial stiffness, atherosclerosis, mitochondrial dysfunction, oxidative stress, calcium homeostasis, and cytoskeletal function. Targeting the AGE/RAGE pathway is a potential therapeutic strategy for ameliorating CVDs. Vitamin D has several beneficial effects on the cardiovascular system. Experimental findings have shown that vitamin D regulates AGE/RAGE signaling and its downstream effects. This article provides a comprehensive review of the mechanistic insights into AGE/RAGE involvement in CVDs and the modulation of the AGE/RAGE signaling pathways by vitamin D.

Sodium hydrosulphide restores tumour necrosis factor-α-induced mitochondrial dysfunction and metabolic dysregulation in HL-1 cells.

Tumour necrosis factor (TNF)-α induces cardiac metabolic disorder and mitochondrial dysfunction. Hydrogen sulphide (H2 S) contains anti-inflammatory and biological effects in cardiomyocytes. This study investigated whether H2 S modulates TNF-α-dysregulated mitochondrial function and metabolism in cardiomyocytes. HL-1 cells were incubated with TNF-α (25 ng/mL) with or without sodium hydrosulphide (NaHS, 0.1 mmol/L) for 24 hours. Cardiac peroxisome proliferator-activated receptor (PPAR) isoforms, pro-inflammatory cytokines, receptor for advanced glycation end products (RAGE) and fatty acid metabolism were evaluated through Western blotting. The mitochondrial oxygen consumption rate and adenosine triphosphate (ATP) production were investigated using Seahorse XF24 extracellular flux analyzer and bioluminescence assay. Fluorescence intensity using 2', 7'-dichlorodihydrofluorescein diacetate was used to evaluate mitochondrial oxidative stress. NaHS attenuated the impaired basal and maximal respiration, ATP production and ATP synthesis and enhanced mitochondrial oxidative stress in TNF-α-treated HL-1 cells. TNF-α-treated HL-1 cells exhibited lower expression of PPAR-α, PPAR-δ, phosphorylated 5' adenosine monophosphate-activated protein kinase-α2, phosphorylated acetyl CoA carboxylase, carnitine palmitoyltransferase-1, PPAR-γ coactivator 1-α and diacylglycerol acyltransferase 1 protein, but higher expression of PPAR-γ, interleukin-6 and RAGE protein than control or combined NaHS and TNF-α-treated HL-1 cells. NaHS modulates the effects of TNF-α on mitochondria and the cardiometabolic system, suggesting its therapeutic potential for inflammation-induced cardiac dysfunction.

Chemical Stability and Transformation of Molybdenum Disulfide Nanosheets in Environmental Media.

Layered transition metal dichalcogenides, including molybdenum disulfide (MoS2), have previously been considered stable in the ambient environment due to the absence of dangling bonds in the electron-filled shells of the end chalcogen atoms. Here, we evaluate the chemical stability of MoS2 nanosheets fabricated by chemical exfoliation (ceMoS2) and surfactant dispersion (sMoS2). The results demonstrate that sMoS2 exhibits greater long-term persistence. Contrarily, ceMoS2 underwent progressive deterioration, in which preferential oxidation of the 1T of a mixture of 1T and 2H phases was observed. The oxidative degradation of ceMoS2 was retarded in the presence of natural organic matter (NOM), including Suwannee River natural organic matter (SRNOM) and Aldrich humic acid (ALHA), in the dark ambient condition, while the aging process of MoS2 with co-occurring ALHA was accelerated under sunlight exposure. The observed inhibition effect on the deterioration of ceMoS2 by NOM was mainly attributed to slower dissolution kinetics with rapid initial oxidation (i.e., forming Mo-O bonding) or carbon grafting, rather than prevention of the formation of secondary small suspended Mo-containing particles. The compiled results highlight that the environmental fate of MoS2 nanosheets will be regulated by the combined effects of exfoliating agents and environmentally relevant factors including organic macromolecules and sunlight exposure.

Calcitriol downregulates fibroblast growth factor receptor 1 through histone deacetylase activation in HL-1 atrial myocytes.

BACKGROUND: Fibroblast growth factor (FGF)-2 plays a crucial role in the pathophysiology of cardiovascular diseases (CVDs). FGF-2 was reported to induce cardiac hypertrophy through activation of FGF receptor 1 (FGFR1). Multiple laboratory findings indicate that calcitriol may be a potential treatment for CVDs. In this study, we attempted to investigate whether calcitriol regulates FGFR1 expression to modulate the effects of FGF-2 signaling in cardiac myocytes and explored the potential regulatory mechanism. METHODS: Western blot, polymerase chain reaction, small interfering RNA, fluorometric activity assay, and chromatin immunoprecipitation (ChIP) analyses were used to evaluate FGFR1, FGFR2, FGFR3, FGFR4, phosphorylated extracellular signal-regulated kinase (p-ERK), ß-myosin heavy chain (ß-MHC), phosphorylated phospholipase Cγ (p-PLCγ), nuclear factor of activated T cells (NFAT), and histone deacetylase (HDAC) expressions and enzyme activities in HL-1 atrial myocytes without and with calcitriol (1 and 10 nM) treatment, in the absence and presence of FGF-2 (25 ng/mL) or suberanilohydroxamic acid (SAHA, a pan-HDAC inhibitor, 1 µM). RESULTS: We found that calcitriol-treated HL-1 cells had significantly reduced FGFR1 expression compared to control cells. In contrast, expressions of FGFR2, FGFR3, and FGFR4 were similar between calcitriol-treated and control HL-1 cells. FGF-2-treated HL-1 cells had similar PLCγ phosphorylation and nuclear/cytoplasmic NFAT expressions compared to control cells. FGF-2 induced lower expressions of p-ERK and ß-MHC in calcitriol-treated HL-1 cells than in control cells. FGFR1-knockdown blocked FGF-2 signaling and reversed the protective effects of calcitriol. Compared to control cells, calcitriol-treated HL-1 cells had higher nuclear HDAC activity. The ChIP analysis demonstrated a significant decrease in acetyl-histone H4, which is associated with an increase in HDAC3 in the FGFR1 promoter. Calcitriol-mediated FGFR1 downregulation was attenuated in the presence of SAHA. CONCLUSIONS: Calcitriol diminished FGFR1 expression through HDAC activation, which ameliorated the harmful effects of FGF-2 on cardiac myocytes.

ADAM10 modulates calcitriol-regulated RAGE in cardiomyocytes.

BACKGROUND: Receptor for advanced glycation end products (RAGE) signalling plays a critical role in the pathogenesis of cardiovascular disease. Calcitriol modulates cardiac RAGE expression. This study explored the mechanisms underlying the effect of calcitriol on RAGE and soluble RAGE (sRAGE) expression in cardiomyocytes. MATERIALS AND METHODS: Western blot, ELISA, fluorometric assay and PCR analyses were used to evaluate the RAGE, sRAGE, endogenous secretory RAGE (esRAGE), Jun N-terminal kinase (JNK), and a disintegrin and metalloprotease 10 (ADAM10) expression and enzyme activity in HL-1 atrial myocytes without and with calcitriol (10 and 100 nM), nuclear factor-κB (NF-κB) inhibitor (50 µg/mL), or ADAM10 inhibitor (5 µM) incubation for 48 h. RESULTS: Calcitriol (10 nM) significantly reduced RAGE protein expression and increased sRAGE concentrations in HL-1 cardiomyocytes compared with control cells. These changes were associated with increased protein expression and enzyme activity of ADAM10 and higher mRNA expression of esRAGE. In the presence of ADAM10 inhibitor, however, the suppressive effect of calcitriol on RAGE was diminished. Methylglyoxal (500 µM for 10 min)-mediated JNK phosphorylation was attenuated in the presence of calcitriol (10 nM). Moreover, control and NF-κB inhibitor-treated HL-1 cells had similar RAGE and sRAGE expression, suggesting that calcitriol-mediated RAGE modulation was independent of NF-κB signalling. CONCLUSIONS: We showed that RAGE downregulation and increased sRAGE production by calcitriol were mediated through ADAM10 activation in cardiomyocytes. The results suggest that calcitriol has therapeutic potential in treating RAGE-mediated cardiovascular complications.

PPARs modulate cardiac metabolism and mitochondrial function in diabetes.

Diabetic cardiomyopathy is a major complication of diabetes mellitus (DM). Currently, effective treatments for diabetic cardiomyopathy are limited. The pathophysiology of diabetic cardiomyopathy is complex, whereas mitochondrial dysfunction plays a vital role in the genesis of diabetic cardiomyopathy. Metabolic regulation targeting mitochondrial dysfunction is expected to be a reasonable strategy for treating diabetic cardiomyopathy. Peroxisome proliferator-activated receptors (PPARs) are master executors in regulating glucose and lipid homeostasis and also modulate mitochondrial function. However, synthetic PPAR agonists used for treating hyperlipidemia and DM have shown controversial effects on cardiovascular regulation. This article reviews our updated understanding of the beneficial and detrimental effects of PPARs on mitochondria in diabetic hearts.

Lithium downregulates phosphorylated acetyl­CoA carboxylase 2 and attenuates mitochondrial fatty acid utilization and oxidative stress in cardiomyocytes.

Acetyl-CoA carboxylase 2 plays a crucial role in regulating mitochondrial fatty acid oxidation in cardiomyocytes. Lithium, a monovalent cation known for its cardioprotective potential, has been investigated for its influence on mitochondrial bioenergetics. The present study explored whether lithium modulated acetyl-CoA carboxylase 2 and mitochondrial fatty acid metabolism in cardiomyocytes and the potential therapeutic applications of lithium in alleviating metabolic stress. Mitochondrial bioenergetic function, fatty acid oxidation, reactive oxygen species production, membrane potential and the expression of proteins involved in fatty acid metabolism in H9c2 cardiomyocytes treated with LiCl for 48 h was measured by using a Seahorse extracellular flux analyzer, fluorescence microscopy and western blotting. Small interfering RNA against glucose transporter type 4 was transfected into H9c2 cardiomyocytes for 48 h to induce metabolic stress mimicking insulin resistance. The results revealed that LiCl at a concentration of 0.3 mM (but not at a concentration of 0.1 or 1.0 mM) upregulated the expression of phosphorylated (p-)glycogen synthase kinase-3 beta and downregulated the expression of p-acetyl-CoA carboxylase 2 but did not affect the expression of adenosine monophosphate-activated protein kinase or calcineurin. Cotreatment with TWS119 (8 µM) and LiCl (0.3 mM) downregulated p-acetyl-CoA carboxylase 2 expression to a similar extent as did treatment with TWS119 (8 µM) alone. Moreover, LiCl (0.3 mM) inhibited mitochondrial fatty acid oxidation, improved coupling efficiency and the cellular respiratory control ratio, hindered reactive oxygen species production and proton leakage and restored mitochondrial membrane potential in glucose transporter type 4 knockdown-H9c2 cardiomyocytes. These findings suggested that low therapeutic levels of lithium can downregulate p-acetyl-CoA carboxylase 2, thus reducing mitochondrial fatty acid oxidation and oxidative stress in cardiomyocytes.

Interleukin-33/ST2 axis involvement in atrial remodeling and arrhythmogenesis.

Interleukin (IL)-33, a cytokine involved in immune responses, can activate its receptor, suppression of tumorigenicity 2 (ST2), is elevated during atrial fibrillation (AF). However, the role of IL-33/ST2 signaling in atrial arrhythmia is unclear. This study explored the pathological effects of the IL-33/ST2 axis on atrial remodeling and arrhythmogenesis. Patch clamping, confocal microscopy, and Western blotting were used to analyze the electrical characteristics of and protein activity in atrial myocytes (HL-1) treated with recombinant IL-33 protein and/or ST2-neutralizing antibodies for 48 hrs. Telemetric electrocardiographic recordings, Masson's trichrome staining, and immunohistochemistry staining of the atrium were performed in mice receiving tail vein injections with nonspecific immunoglobulin (control), IL-33, and IL-33 combined with anti-ST2 antibody for 2 weeks. IL-33-treated HL-1 cells had a reduced action potential duration, lower L-type Ca2+ current, greater sarcoplasmic reticulum (SR) Ca2+ content, increased Na+/Ca2+ exchanger (NCX) current, elevation of K+ currents, and increased intracellular calcium transient. IL-33-treated HL-1 myocytes had greater activation of the calcium-calmodulin-dependent protein kinase II (CaMKII)/ryanodine receptor 2 (RyR2) axis and nuclear factor kappa B (NF-κB) / NLR family pyrin domain containing 3 (NLRP3) signaling than did control cells. IL-33 treated cells also had greater expression of Nav1.5, Kv1.5, NCX, and NLRP3 than did control cells. Pretreatment with neutralizing anti-ST2 antibody attenuated IL-33-mediated activation of CaMKII/RyR2 and NF-κB/NLRP3 signaling. IL-33-injected mice had more atrial ectopic beats and increased AF episodes, greater atrial fibrosis, and elevation of NF-κB/NLRP3 signaling than did controls or mice treated with IL-33 combined with anti-ST2 antibody. Thus, IL-33 recombinant protein treatment promotes atrial remodeling through ST2 signaling. Blocking the IL-33/ST2 axis might be an innovative therapeutic approach for patients with atrial arrhythmia and elevated serum IL-33.

Short-chain fatty acid butyrate against TMAO activating endoplasmic-reticulum stress and PERK/IRE1-axis with reducing atrial arrhythmia.

INTRODUCTION: The accumulation of microbiota-derived trimethylamine N-oxide (TMAO) in the atrium is linked to the development and progression of atrial arrhythmia. Butyrate, a major short-chain fatty acid, plays a crucial role in sustaining intestinal homeostasis and alleviating systemic inflammation, which may reduce atrial arrhythmogenesis. OBJECTIVES: This study explored the roles of butyrate in regulating TMAO-mediated atrial remodeling and arrhythmia. METHODS: Whole-cell patch clamp experiments, Western blotting, and immunocytochemistry were used to analyze electrical activity and signaling, respectively, in TMAO-treated HL-1 atrial myocytes with or without sodium butyrate (SB) administration. Telemetry electrocardiographic recording and echocardiography and Masson's trichrome staining and immunohistochemistry were employed to examine atrial function and histopathology, respectively, in mice treated with TMAO with and without SB administration. RESULTS: Compared with control cells, TMAO-treated HL-1 myocytes exhibited reduced action potential duration (APD), elevated sarcoplasmic reticulum (SR) calcium content, larger L-type calcium current (ICa-L), increased Na+/Ca2+ exchanger (NCX) current, and increased potassium current. However, the combination of SB and TMAO resulted in similar APD, SR calcium content, ICa-L, transient outward potassium current (Ito), and ultrarapid delayed rectifier potassium current (IKur) compared with controls. Additionally, TMAO-treated HL-1 myocytes exhibited increased activation of endoplasmic reticulum (ER) stress signaling, along with increased PKR-like ER stress kinase (PERK)/IRE1α axis activation and expression of phospho-IP3R, NCX, and Kv1.5, compared with controls or HL-1 cells treated with the combination of TMAO and SB. TMAO-treated mice exhibited atrial ectopic beats, impaired atrial function, increased atrial fibrosis, and greater activation of ER stress signaling with PERK/IRE1α axis activation compared with controls and mice treated with TMAO combined with SB. CONCLUSION: TMAO administration led to PERK/IRE1α axis activation, which may increase atrial remodeling and arrhythmogenesis. SB treatment mitigated TMAO-elicited ER stress. This finding suggests that SB administration is a valuable strategy for treating TMAO-induced atrial arrhythmia.

Pheochromocytoma mimicking both acute coronary syndrome and sepsis: a case report.

OBJECTIVE: To present an atypical manifestation in a patient with pheochromocytoma. CLINICAL PRESENTATION AND INTERVENTION: A 48-year-old man presented with chest pain, fever and leukocytosis. Elevated cardiac biomarkers and diffuse ST-T abnormalities on electrocardiography suggested myocardial infarction. However, coronary angiography showed normal coronary arteries. Abdominal computed tomography revealed a left adrenal tumor of 6.7 × 6.8 cm. Paroxysmal fluctuation of blood pressure raised the suspicion of pheochromocytoma, which was further supported by elevated urine catecholamine levels. He underwent left adrenalectomy and pathological findings confirmed the diagnosis. CONCLUSION: Pheochromocytoma should be considered as part of the differential diagnosis in a patient with symptoms suggestive of both acute coronary syndrome and sepsis.

Polypyrrole-induced active-edge-S and high-valence-Mo reinforced composites with boosted electrochemical performance for the determination of 2,4,6-trichlorophenol in the aquatic environment.

With the extensive application of halogenated aromatic compounds, including 2,4,6-Trichlorophenol (2,4,6-TCP), improper treatment or discharge contribute to persistently harmful effects on humans and the ecosystem, rendering the identification and monitoring of 2,4,6-TCP in the aquatic environment urgently required. In this study, a highly sensitive electrochemical platform was developed using active-edge-S and high-valence-Mo rich MoS2/polypyrrole composites. MoS2/PPy illustrates superior electrochemical performance and catalytic activity and has not been explored for detecting chlorinated phenols previously. The local environment of polypyrrole induces the richness of active edge S and a high oxidation state of Mo species in the composites, both of which endorse a sensitive anodic current response due to the favored oxidation of 2,4,6-TCP through nucleophilic substitution. Also, the higher complementarity between pyrrole and 2,4,6-TCP with respective electron-rich and electron-poor features through π-π stacking interactions enhances the specific detection capability of 2,4,6-TCP by the MoS2/polypyrrole-modified electrode. The MoS2/polypyrrole-modified electrode achieved a linear range of 0.1-260 µM with an ultralow limit of detection of 0.009 µM. Additionally, the structural stability boosted by the linkage of polypyrrole and MoS2 results in good resistance and satisfactory recovery in real water samples. The compiled results demonstrate that the proposed MoS2/polypyrrole composite opens up a new potential to advance a sensitive, selective, facile fabrication, and low-cost platform for the on-site determination of 2,4,6-TCP in aquatic systems. The sensing of 2,4,6-TCP is important to monitor its occurrence and transport, and can also serve to track the effectiveness and adjust subsequent remediation treatments applied to contaminated sites.

Recovery and repurposing of waste isopropanol with CO2-switchable deep eutectic solvents.

Large amounts of waste isopropanol (IPA) are generated in industry, rendering the recovery of IPA highly desirable due to the economic and environmental benefits. Because it forms an azeotropic mixture with water, IPA is difficult to separate from the waste stream. In the present work, a novel CO2-switchable monoethanolamine-butanol deep eutectic solvent (DES) ([MEA][BuOH]) was identified as a superior medium for separating IPA and water at ambient temperature by forming butanol-IPA mixtures. The switchable solvent system combines the advantages of homogeneous and heterogeneous systems, i.e., rapid mixing due to the low mass transfer limitations and facile product separation, respectively. The low viscosity of [MEA][BuOH], the similar physical features (polarity, dipole moment, and dielectric constant) of butanol and IPA, and the H-bonding interactions of [BuOH] with IPA are thought to enable effective IPA capture from water by the butanol. Recovery of the IPA and formation of a butanol-IPA mixture is appealing because the resultant mixture could serve as an additive or substitute for alternative fuels. The results suggest that the developed process will provide a low-cost, energy-saving, effective, and environmentally benign route to recycling and repurposing waste IPA, an environmental hazard, as a potential alternative fuel.