Ferroptosis: A potential target of macrophages in plaque vulnerability.

Plaque vulnerability has been the subject of several recent studies aimed at reducing the risk of stroke and carotid artery stenosis. Atherosclerotic plaque development is a complex process involving inflammation mediated by macrophages. Plaques become more vulnerable when the equilibrium between macrophage recruitment and clearance is disturbed. Lipoperoxides, which are affected by iron levels in cells, are responsible for the cell death seen in ferroptosis. Ferroptosis results from lipoperoxide-induced mitochondrial membrane toxicity. Atherosclerosis in ApoE(-/-) mice is reduced when ferroptosis is inhibited and iron intake is limited. Single-cell sequencing revealed that a ferroptosis-related gene was substantially expressed in atherosclerosis-modeled macrophages. Since ferroptosis can be regulated, it offers hope as a non-invasive method of treating carotid plaque. In this study, we discuss the role of ferroptosis in atherosclerotic plaque vulnerability, including its mechanism, regulation, and potential future research directions.

Cardiovascular Protection with a Long-Acting GLP-1 Receptor Agonist Liraglutide: An Experimental Update.

Angiotensin II (Ang II), a peptide hormone generated as part of the renin-angiotensin system, has been implicated in the pathophysiology of many cardiovascular diseases such as peripheral artery disease, heart failure, hypertension, coronary artery disease and other conditions. Liraglutide, known as an incretin mimetic, is one of the glucagon-like peptide-1 (GLP-1) receptor agonists, and has been proven to be effective in the treatment of cardiovascular disorders beyond adequate glycemic control. The objective of this review is to compile our recent experimental outcomes-based studies, and provide an overview the cardiovascular protection from liraglutide against Ang II- and pressure overload-mediated deleterious effects on the heart. In particular, the mechanisms of action underlying the inhibition of oxidative stress, vascular endothelial dysfunction, hypertension, cardiac fibrosis, left ventricular hypertrophy and heart failure with liraglutide are addressed. Thus, we support the notion that liraglutide continues to be a useful add-on therapy for the management of cardiovascular diseases.

Nickel Foam Coated by Ni Nanoparticle-Decorated 3D Nanocarbons as a Freestanding Host for High-Performance Lithium-Sulfur Batteries.

Nanocarbons (NCs) consisting of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) were coated on the surface of nickel foam (NF) via a chemical vapor deposition method. The CNFs formed conductive networks on NF, while the CNTs grew perpendicular to the surface of the CNFs, accompanied with the formation of Ni nanoparticles (Ni NPs) at the end of CNTs. The unique Ni-NCs-coated NF with a porous structure was applied as the three-dimensional (3D) current collector of lithium-sulfur (Li-S) batteries, which provided enough space to accommodate the electrode materials inside itself. Therefore, the 3D interconnected conductive framework of the coated NF collector merged in the electrode materials shortened the path of electron transport, and the generated Ni NPs could adsorb lithium polysulfides (LiPSs) and effectively accelerated the conversion kinetics of LiPSs as well, thereby suppressing the "shuttle effect". Moreover, the rigid framework of NF would also constrain the movement of the electrode compositions, which benefited the stability of the Li-S batteries. As a matter of fact, the Li-S battery based on the Ni-NCs-coated NF collector delivered an initial discharge capacity as high as 1472 mAh g-1 at 0.1C and outstanding high rate capability at 3C (802 mAh g-1). Additionally, low decay rates of 0.067 and 0.08% at 0.2C (300 cycles) and 0.5C (500 cycles) have been obtained, respectively. Overall, our prepared Ni-NCs-coated NF collector is promising for the application in high-performance Li-S batteries.

Suppression of angiotensin II-activated NOX4/NADPH oxidase and mitochondrial dysfunction by preserving glucagon-like peptide-1 attenuates myocardial fibrosis and hypertension.

This study aims to investigate whether stabilization of glucagon-like peptide-1 (GLP-1) level reduces angiotensin II (Ang II)-induced cardiac fibrosis and -elevated blood pressure accompanying with inhibition of NADPH oxidase (NOX) expression and preservation of mitochondrial integrity. The study was performed in Sprague-Dawley rat model of Ang II infusion (500 ng/kg/min) using osmotic minipumps for 4 weeks. GLP-1 receptor agonist liraglutide (0.3 mg/kg, injected subcutaneously twice daily) and dipeptidyl peptides-4 inhibitor, linagliptin (8 mg/kg, administered via oral gavage) were selected to preserve GLP-1 level. Blood pressure was measured noninvasively. Heart and aorta were saved for histological analysis. Relative to the animals with Ang II infusion, in the heart, liraglutide and linagliptin comparatively reduced the protein levels of NOX4 and TGFß1 and expression of monocyte chemoattractant protein 1, and attenuated the proliferation of myofibroblasts (15 ± 4 and 13 ± 3 vs. 42 ± 22/HPF in Ang II group). The number of distorted mitochondria in both groups was significantly reduced (8 ± 4 and 10 ± 6 vs. 27 ± 13/HPF in Ang II group), in company with a significant reduction in cardiac fibrosis. In the aorta, treatment with liraglutide and linagliptin significantly downregulated the expression of NOX4 and intercellular adhesion molecule 1, and enhanced endothelial NOS expression. Aortic wall thickness was reduced comparatively (267 ± 22 and 286 ± 25 vs. 339 ± 40 µm in Ang II group). The area of fibrotic aorta was also reduced (13 ± 6 and 14 ± 5 vs. 38 ± 24 mm2 in Ang II group), respectively, in coincidence with a significant reduction in mean blood pressure. Taken together, these results suggest that the conservation of GLP-1 level with exogenous supply of liraglutide or the prevention of endogenous degradation of GLP-1 with linagliptin protects against Ang II-induced injury in the heart and aorta, potentially associated with inhibition of NOX4 expression and preservation of mitochondrial integrity.

Efficacy and safety of long-term transcutaneous electroacupuncture versus sham transcutaneous electroacupuncture for delayed gastric emptying after distal gastrectomy: study protocol for a randomized, patient-assessor blinded, controlled trial.

BACKGROUND: Delayed gastric emptying (DGE) after distal gastrectomy impacts patients' nutritional status and quality of life. The current treatments of DGE seem unsatisfactory or need invasive interventions. It is unknown whether transcutaneous electroacupuncture (TEA) is effective in treating DGE. METHODS: A total of 90 eligible participants who underwent distal gastrectomy will be randomly allocated to either the TEA group (n = 60) or the sham transcutaneous electroacupuncture (sham-TEA) group (n = 30). Each participant will receive TEA on the bilateral acupoints of Zusanli (ST36) and Neiguan (PC6) for 4 weeks. The primary outcomes will be the residual rates of radioactivity in the stomach by gastric scintigraphy and total response rates. The secondary outcomes will be endoscopic features, autonomic function, nutritional and psychological status, serum examination, and quality of life (QoL). The adverse events will also be reported. The patients will be followed up 1 year after the treatment. DISCUSSION: The findings of this randomized trial will provide high-quality evidence regarding the efficacy and safety of long-term TEA for treating DGE after distal gastrectomy. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2000033965. Registered on 20 June 2020.

A Novel Mitochondrial Complex of Aldosterone Synthase, Steroidogenic Acute Regulatory Protein, and Tom22 Synthesizes Aldosterone in the Rat Heart.

Aldosterone, which regulates renal salt retention, is synthesized in adrenocortical mitochondria in response to angiotensin II. Excess aldosterone causes myocardial injury and heart failure, but potential intracardiac aldosterone synthesis has been controversial. We hypothesized that the stressed heart might produce aldosterone. We used blue native gel electrophoresis, immunoblotting, protein crosslinking, coimmunoprecipitations, and mass spectrometry to assess rat cardiac aldosterone synthesis. Chronic infusion of angiotensin II increased circulating corticosterone levels 350-fold and induced cardiac fibrosis. Angiotensin II doubled and telmisartan inhibited aldosterone synthesis by heart mitochondria and cardiac production of aldosterone synthase (P450c11AS). Heart aldosterone synthesis required P450c11AS, Tom22 (a mitochondrial translocase receptor), and the intramitochondrial form of the steroidogenic acute regulatory protein (StAR); protein crosslinking and coimmunoprecipitation studies showed that these three proteins form a 110-kDa complex. In steroidogenic cells, extramitochondrial (37-kDa) StAR promotes cholesterol movement from the outer to inner mitochondrial membrane where cholesterol side-chain cleavage enzyme (P450scc) converts cholesterol to pregnenolone, thus initiating steroidogenesis, but no function has previously been ascribed to intramitochondrial (30-kDa) StAR; our data indicate that intramitochondrial 30-kDa StAR is required for aldosterone synthesis in the heart, forming a trimolecular complex with Tom22 and P450c11AS. This is the first activity ascribed to intramitochondrial StAR, but how this promotes P450c11AS activity is unclear. The stressed heart did not express P450scc, suggesting that circulating corticosterone (rather than intracellular cholesterol) is the substrate for cardiac aldosterone synthesis. Thus, the stressed heart produced aldosterone using a previously undescribed intramitochondrial mechanism that involves P450c11AS, Tom22, and 30-kDa StAR. SIGNIFICANCE STATEMENT: Prior studies of potential cardiac aldosterone synthesis have been inconsistent. This study shows that the stressed rat heart produces aldosterone by a novel mechanism involving aldosterone synthase, Tom22, and intramitochondrial steroidogenic acute regulatory protein (StAR) apparently using circulating corticosterone as substrate. This study establishes that the stressed rat heart produces aldosterone and for the first time identifies a biological role for intramitochondrial 30-kDa StAR.

Aerobic degradation of 4-fluoroaniline and 2,4-difluoroaniline: performance and microbial community in response to the inocula.

In this study, a distinct inoculum was investigated as an isolated variable within sequencing batch reactors via a comparison of the 4-fluoroaniline (4-FA) or 2,4-difluoroaniline (2,4-DFA) removal amounts. The inocula were derived from a treatment plant for treating pharmaceutical wastewater plus a small amount of municipal sewage (PMS), a treatment plant for treating fluoridated hydrocarbon wastewater (FHS), and a treatment plant for treating the comprehensive wastewater in an industrial park (CIS). There were slight differences among the degradation patterns of the 4-FA for the three inocula, whether during the enrichment period or the high concentration shock period. In contrast, it was observed that the degradation efficiency of 2,4-DFA initially varied with the inocula. The FHS-derived inoculum was determined to be optimal, exhibiting the earliest degradation reaction only after an acclimation of 7 days had the highest degradation rate constant of 0.519 h-1, and had the fastest recovery time of three weeks after high concentration shock. Additionally, compared with the PMS-derived inoculum, the CIS-derived inoculum exhibited an earlier degradation reaction within three weeks, and a higher microbial diversity, but a lower shock resistance and degradation rate constant of 0.257 h-1. High-throughput sequencing demonstrated that each final consortium was different in composition, and the microbial consortia developed well on the inoculum and substrate. In comparison of the similarity among the three 2,4-DFA enrichment cultures, the higher similarity (63.9-70.0%) among three final consortia enriching with 4-FA was observed. The results indicated that the inoculum played an important role in the degradation of FAs and the microbial bacterial communities of final consortia, and the effect extent might well depend on the fluorinated level of FAs.

Glucagon-Like Peptide-1 Analog Liraglutide Attenuates Pressure-Overload Induced Cardiac Hypertrophy and Apoptosis through Activating ATP Sensitive Potassium Channels.

PURPOSE: This study aimed to investigate whether inhibition of glucagon-like peptide-1 (GLP-1) on pressure overload induced cardiac hypertrophy and apoptosis is related to activation of ATP sensitive potassium (KATP) channels. METHODS: Male SD rats were randomly divided into five groups: sham, control (abdominal aortic constriction), GLP-1 analog liraglutide (0.3 mg/kg/twice day), KATP channel blocker glibenclamide (5 mg/kg/day), and liraglutide plus glibenclamide. RESULTS: Relative to the control on week 16, liraglutide upregulated protein and mRNA levels of KATP channel subunits Kir6.2/SUR2 and their expression in the myocardium, vascular smooth muscle, aortic endothelium, and cardiac microvasculature. Consistent with a reduction in aortic wall thickness (61.4 ± 7.6 vs. 75.0 ± 7.6 µm, p < 0.05), liraglutide enhanced maximal aortic endothelium-dependent relaxation in response to acetylcholine (71.9 ± 8.7 vs. 38.6 ± 4.8%, p < 0.05). Along with a reduction in heart to body weight ratio (2.6 ± 0.1 vs. 3.4 ± 0.4, mg/g, p < 0.05) by liraglutide, hypertrophied cardiomyocytes (371.0 ± 34.4 vs. 933.6 ± 156.6 µm2, p < 0.05) and apoptotic cells (17.5 ± 8.2 vs. 44.7 ± 7.9%, p < 0.05) were reduced. Expression of anti-apoptotic protein BCL-2 and contents of myocardial ATP were augmented, and expression of cleaved-caspase 3 and levels of serum Tn-I/-T were reduced. Echocardiography and hemodynamic measurement showed that cardiac systolic function was enhanced as evidenced by increased ejection fraction (88.4 ± 4.8 vs. 73.8 ± 5.1%, p < 0.05) and left ventricular systolic pressure (105.2 ± 10.8 vs. 82.7 ± 7.9 mmHg, p < 0.05), and diastolic function was preserved as shown by a reduction of ventricular end-diastolic pressure (-3.1 ± 2.9 vs. 6.7 ± 2.8 mmHg, p < 0.05). Furthermore, left ventricular internal diameter at end-diastole (5.8 ± 0.5 vs. 7.7 ± 0.6 mm, p < 0.05) and left ventricular internal diameter at end-systole (3.0 ± 0.6 vs. 4.7 ± 0.4 mm, p < 0.05) were improved. Dietary administration of glibenclamide alone did not alter all the parameters measured but significantly blocked liraglutide-exerted cardioprotection. CONCLUSION: Liraglutide ameliorates cardiac hypertrophy and apoptosis, potentially via activating KATP channel-mediated signaling pathway. These data suggest that liraglutide might be considered as an adjuvant therapy to treat patients with heart failure.

Exogenous supplement of glucagon like peptide-1 protects the heart against aortic banding induced myocardial fibrosis and dysfunction through inhibiting mTOR/p70S6K signaling and promoting autophagy.

Mammalian target of rapamycin (mTOR) and a ribosomal protein S6 kinase (p70S6K) mediate tissue fibrosis and negatively regulate autophagy. This study aims to investigate whether glucagon-like peptide-1 (GLP-1) analog liraglutide protects the heart against aortic banding-induced cardiac fibrosis and dysfunction through inhibiting mTOR/p70S6K signaling and promoting autophagy activity. Male SD rats were randomly divided into four groups (n = 6/each group): sham operated control; abdominal aortic constriction (AAC); liraglutide treatment during AAC (0.3 mg/kg, injected subcutaneously twice daily); rapamycin treatment during AAC (0.2 mg/kg/day, administered by gastric gavage). Relative to the animals with AAC on week 16, liraglutide treatment significantly reduced heart/body weight ratio, inhibited cardiomyocyte hypertrophy, and augmented plasma GLP-1 level and tissue GLP-1 receptor expression. Phosphorylation of mTOR/p70S6K, populations of myofibroblasts and synthesis of collagen I/III in the myocardium were simultaneously inhibited. Furthermore, autophagy regulating proteins: LC3-II/LC3-I ratio and Beclin-1 were upregulated, and p62 was downregulated by liraglutide. Compared with liraglutide group, treatment with rapamycin, a specific inhibitor of mTOR, compatibly augmented GLP-1 receptor level, inhibited phosphorylation of mTOR/p70S6K and expression of p62 as well as increased level of LC3-II/LC3-I ratio and Beclin-1, suggesting that there is an interaction between GLP-1 and mTOR/p70S6K signaling in the regulation of autophagy. In line with these modifications, treatment with liraglutide and rapamycin significantly reduced perivascular/interstitial fibrosis, and preserved systolic/diastolic function. These results suggest that the inhibitory effects of liraglutide on cardiac fibrosis and dysfunction are potentially mediated by inhibiting mTOR/p70S6K signaling and enhancing autophagy activity.

Conservation of glucagon like peptide-1 level with liraglutide and linagilptin protects the kidney against angiotensin II-induced tissue fibrosis in rats.

This study tested the hypothesis that the enhancement of glucagon-like peptide-1 (GLP-1) level through either exogenous supply of GLP-1 agonist, liraglutide or prevention of endogenous GLP-1 degradation with dipeptidyl peptidease-4 inhibitor, lingaliptin ameliorates angiotensin II (Ang II)-induced renal fibrosis. Sprague-Dawley rats were randomly divided into four groups: 0.9% saline or Ang II (500 ng/kg/min) was infused with osmotic minipumps for 4 weeks, defined as sham and Ang II groups. In drug treated groups, liraglutide (0.3 mg/kg) was injected subcutaneously twice daily or linagliptin (8 mg/kg) was administered daily via oral gavage during Ang II infusion. Compared with Ang II stimulation, liraglutide or linagliptin comparatively down-regulated the protein level of the AT1 receptor, and up-regulated the AT2 receptor, as identified by a reduced AT1/AT2 ratio (all p < 0.05), consistent with less locally-expressed AT1 receptor and enhanced AT2 receptor in the glomerular capillaries and proximal tubules of the renal cortex. Furthermore, both drugs significantly increased the expression of GLP-1 receptor and attenuated the protein levels of TLR4, NOX4 and IL-6. The populations of macrophages and α-SMA expressing myofibroblasts decreased with treatment of liraglutide and linagliptin, in coincidence with the reduced expression of phosphor-Smad2/3, Smad4, TGFß1, and up-regulated Smad7. Along with these modulations, renal morphology was preserved and synthesis of fibronectin/collagen I was down-regulated, as identified by small collagen-rich area in the renal cortex. These results suggest that the preservation of GLP-1 level using liraglutide or linagliptin might be considered as an add-on therapeutic option for inhibiting Ang II induced renal fibrosis and failure.

Steroidogenic acute regulatory protein/aldosterone synthase mediates angiotensin II-induced cardiac fibrosis and hypertrophy.

Aldosterone produced in adrenal glands by angiotensin II (Ang II) is known to elicit myocardial fibrosis and hypertrophy. This study was designed to test the hypothesis that Ang II causes cardiac morphological changes through the steroidogenic acute regulatory protein (StAR)/aldosterone synthase (AS)-dependent aldosterone synthesis primarily initiated in the heart. Sprague-Dawley rats were randomized to following groups: Ang II infusion for a 4-week period, treatment with telmisartan, spironolactone or adrenalectomy during Ang II infusion. Sham-operated rats served as control. Relative to Sham rats, Ang II infusion significantly increased the protein levels of AT1 receptor, StAR, AS and their tissue expression in the adrenal glands and heart. In coincidence with reduced aldosterone level in the heart, telmisartan, an AT1 receptor blocker, significantly down-regulated the protein level and expression of StAR and AS. Ang II induced changes in the expression of AT1/StAR/AS were not altered by an aldosterone receptor antagonist spironolactone. Furthermore, Ang II augmented migration of macrophages, protein level of TGFß1, phosphorylation of Smad2/3 and proliferation of myofibroblasts, accompanied by enhanced perivascular/interstitial collagen deposition and cardiomyocyte hypertrophy, which all were significantly abrogated by telmisartan or spironolactone. However, adrenalectomy did not fully suppress Ang II-induced cell migration/proliferation and fibrosis/hypertrophy, indicating a role of aldosterone synthesized within the heart in pathogenesis of Ang II induced injury. These results indicate that myocardial fibrosis and hypertrophy stimulated by Ang II is associated with tissue-specific activation of aldosterone synthesis, primarily mediated by AT1/StAR/AS signaling pathways.

Aerobic degradation of 2- and 3-fluoroaniline in mixed culture systems and microbial community analysis.

Among three monofluoroanilines, 2-fluoroaniline (2-FA) and 3-fluoroaniline (3-FA) exhibit relatively poor biodegradability. This work examined their degradation characteristics in a mixed culture system and also analyzed the microorganism community. After acclimation for 58 d and 43 d, the high removal efficiency of 100% of 2-FA and 95.3% of 3-FA was obtained by adding 25 mg L-1 of 2-FA or 3-FA to the two reactors, respectively. In addition, the high defluorination rates of 2-FA and 3-FA were observed to be 87.0% and 89.3%, respectively. The degradation kinetics showed that the maximum specific degradation rates of 2-FA and 3-FA were (21.23 ± 0.91) mg FA (g•VSS·h)-1, and (11.75 ± 0.99) mg FA (g•VSS·h)-1, respectively. PCR-DGGE analysis revealed that the unique bacteria degrading 2-FA were mainly composed of six genera (Novosphingobium, Bradyrhizobium, Aquaspirillum, Aminobacter, Ochrobactrum, and Labrys), and five genera that degraded 3-FA (Ochrobactrum, Aquaspirillum, Lachnobacterium, Bradyrhizobium, and Variovorax). Analysis of the key catabolic enzyme activities indicated that the simultaneous hydroxylation and dehalogenation were involved in monooxygenase elimination of 2-FA and conversion of 3-FA to 4-fluorocatechol by dioxygenase, indicating that enriched mixed cultures were effective to metabolize 2-FA or 3-FA by unconventional pathways to prevent the accumulation of toxic metabolites.

Liraglutide attenuates cardiac remodeling and improves heart function after abdominal aortic constriction through blocking angiotensin II type 1 receptor in rats.

OBJECTIVE: Angiotensin II (Ang II) is known to contribute to the pathogenesis of heart failure by eliciting cardiac remodeling and dysfunction. The glucagon-like peptide-1 (GLP-1) has been shown to exert cardioprotective effects in animals and patients. This study investigates whether GLP-1 receptor agonist liraglutide inhibits abdominal aortic constriction (AAC)-induced cardiac fibrosis and dysfunction through blocking Ang II type 1 receptor (AT1R) signaling. METHODS: Sprague-Dawley rats were subjected to sham operation and abdominal aortic banding procedure for 16 weeks. In treated rats, liraglutide (0.3 mg/kg) was subcutaneously injected twice daily or telmisartan (10 mg/kg/day), the AT1R blocker, was administered by gastric gavage. RESULTS: Relative to the animals with AAC, liraglutide reduced protein level of the AT1R and upregulated the AT2R, as evidenced by reduced ratio of AT1R/AT2R (0.59±0.04 vs. 0.91±0.06, p<0.05). Furthermore, the expression of angiotensin converting enzyme 2 was upregulated, tissue levels of malondialdehyde and B-type natriuretic peptide were reduced, and superoxide dismutase activity was increased. Along with a reduction in HW/BW ratio, cardiomyocyte hypertrophy was inhibited. In coincidence with these changes, liraglutide significantly decreased the populations of macrophages and myofibroblasts in the myocardium, which were accompanied by reduced protein levels of transforming growth factor beta1, Smad2/3/4, and upregulated smad7. The synthesis of collagen I and III was inhibited and collagen-rich fibrosis was attenuated. Consistent with these findings, cardiac systolic function was preserved, as shown by increased left ventricular systolic pressure (110±5 vs. 99±2 mmHg, p<0.05), ejection fraction (83%±2% vs. 69%±4%, p<0.05) and fraction shortening (49%±2% vs. 35%±3%, p<0.05). Treatment with telmisartan provided a comparable level of protection as compared with liraglutide in all the parameters measured. CONCLUSION: Taken together, liraglutide ameliorates cardiac fibrosis and dysfunction, potentially via suppressing the AT1R-mediated events. These data indicate that liraglutide might be selected as an add-on drug to prevent the progression of heart failure.

Degradation of 3-fluoroanilne by Rhizobium sp. JF-3.

The interest of fluoroanilines in the environment is due to their extensive applications in industry and their low natural biodegradability. A pure bacterial strain capable of degrading 3-fluoroaniline (3-FA) as the sole source of carbon and energy was isolated from a sequencing batch reactor operating for the treatment of 3-FA. The strain (designated as JF-3) was identified by 16S rRNA gene analysis as a member of the genus Rhizobium. When grown in 3-FA medium at concentrations of 100-700 mg/L, strain JF-3 almost completely removed 3-FA within 72 h. However, the obvious cell growth inhibition was observed in cultures treated with 3-FA concentrations greater than 500 mg/L. The degradation kinetics of 3-FA were consistent with Haldane's model with the maximum degradation rate as 67.66 mg/(g dry cell h). The growth kinetics of strain JF-3 followed Andrew's model with the maximum growth rate as 30.87 h-1. Also, strain JF-3 was able to degrade 4-fluoroaniline, aniline, and catechol, but hardly grew on 2-fluoroaniline, 2,4-dfluoroaniline, 2,3,4-trifluoroaniline, 3-fluorocatechol, and 4-fluorocatechol. Additionally, it was able to grow over a wide pH range (pH 6-10), and also showed tolerance to salinity with lower than 1.0%. This result, in combination with the enzyme assays and analysis of metabolite intermediates, indicated an unconventional pathway for 3-fluoroaniline metabolism that involved conversion to 3-aminophenol and resorcinol by monooxygenase, and which was subsequently metabolized via the ortho-cleavage pathway. To our knowledge, this is the first report on the utilization of 3-FA as a growth substrate by Rhizobium sp.

CD44 Deficiency in Mice Protects the Heart Against Angiotensin Ii-Induced Cardiac Fibrosis.

This study tested the hypothesis that CD44 is involved in the development of cardiac fibrosis via angiotensin II (Ang II) AT1 receptor-stimulated TNFα/NFκB/IκB signaling pathways. Study was conducted in C57BL/6 wild type and CD44 knockout mice subjected to Ang II infusion (1,000 ng/kg/min) using osmotic minipumps up to 4 weeks or with gastric gavage administration of the AT1 receptor blocker, telmisartan at a dose of 10 mg/kg/d. Results indicated that Ang II enhances expression of the AT1 receptor, TNFα, NFκB, and CD44 as well as downregulates IκB. Further analyses revealed that Ang II increases macrophage migration, augments myofibroblast proliferation, and induces vascular/interstitial fibrosis. Relative to the Ang II group, treatment with telmisartan significantly reduced expression of the AT1 receptor and TNFα. These changes occurred in coincidence with decreased NFκB, increased IκB, and downregulated CD44 in the intracardiac vessels and intermyocardium. Furthermore, macrophage migration and myofibroblast proliferation were inhibited and fibrosis was attenuated. Knockout of CD44 did not affect Ang II-stimulated AT1 receptor and modulated TNFα/NFκB/IκB signaling, but significantly reduced macrophage/myofibroblast-mediated fibrosis as identified by less extensive collagen-rich area. These results suggest that the AT1 receptor is involved in the development of cardiac fibrosis by stimulating TNFα/NFκB/IκB-triggered CD44 signaling pathways. Knockout of CD44 blocked Ang II-induced cell migration/proliferation and cardiac fibrosis. Therefore, selective inhibition of CD44 may be considered as a potential therapeutic target for attenuating Ang II-induced deleterious cardiovascular effects.

Curcumin inhibits cardiac hypertrophy and improves cardiovascular function via enhanced Na+/Ca2+ exchanger expression after transverse abdominal aortic constriction in rats.

BACKGROUND: This study tested the hypothesis that inhibition of cardiac hypertrophy and preservation of cardiac/endothelial function by the natural yellow pigment curcumin are associated with upregulated expression of Na+/Ca2+ exchanger (NCX) after transverse aortic constriction (TAC). METHODS: Male Wistar rats were subjected to TAC for 10 weeks and curcumin (50 mg/kg/day) was fed by gastric gavage during TAC. Expression of NCX and endothelial nitric oxide synthase (eNOS) was analyzed by Western blot and immunohistochemistry. RESULTS: Compared with the animals in the TAC group, curcumin significantly increased the survival rate and reduced the ratio of heart or left ventricle (LV) to body weight and the cross sectional area of cardiomyocytes. In coincidence with improved LV systolic pressure and reduced LV end-diastolic pressure, curcumin significantly reduced LV end-systolic and diastolic diameter/dimension, and enhanced LV ejection fraction and LV fractional shortening as measured by echocardiography. Furthermore, endothelium-dependent relaxation of aortic rings in response to acetylcholine was significantly improved by curcumin. Along with these modifications, the expression and localization of NCX and eNOS in the myocardium and vascular endothelium were significantly upregulated by curcumin. The protective effect of curcumin on endothelium-dependent relaxation was partly blocked by pretreatment with the NCX inhibitor, KB-R7943. CONCLUSIONS: These results demonstrate that inhibition of cardiac hypertrophy, improvement of cardiac systolic/diastolic function and preservation of vascular endothelium by curcumin might be associated with upregulated NCX expression level in response to increased afterload.

Edaravone inhibits pressure overload-induced cardiac fibrosis and dysfunction by reducing expression of angiotensin II AT1 receptor.

Angiotensin II (Ang II) is known to be involved in the progression of ventricular dysfunction and heart failure by eliciting cardiac fibrosis. The purpose of this study was to demonstrate whether treatment with an antioxidant compound, edaravone, reduces cardiac fibrosis and improves ventricular function by inhibiting Ang II AT1 receptor. The study was conducted in a rat model of transverse aortic constriction (TAC). In control, rats were subjected to 8 weeks of TAC. In treated rats, edaravone (10 mg/kg/day) or Ang II AT1 receptor blocker, telmisartan (10 mg/kg/day) was administered by intraperitoneal injection or gastric gavage, respectively, during TAC. Relative to the animals with TAC, edaravone reduced myocardial malonaldehyde level and increased superoxide dismutase activity. Protein level of the AT1 receptor was reduced and the AT2 receptor was upregulated, as evidenced by the reduced ratio of AT1 over AT2 receptor (0.57±0.2 vs 3.16±0.39, p<0.05) and less locally expressed AT1 receptor in the myocardium. Furthermore, the protein level of angiotensin converting enzyme 2 was upregulated. In coincidence with these changes, edaravone significantly decreased the populations of macrophages and myofibroblasts in the myocardium, which were accompanied by reduced levels of transforming growth factor beta 1 and Smad2/3. Collagen I synthesis was inhibited and collagen-rich fibrosis was attenuated. Relative to the TAC group, cardiac systolic function was preserved, as shown by increased left ventricular systolic pressure (204±51 vs 110±19 mmHg, p<0.05) and ejection fraction (82%±3% vs 60%±5%, p<0.05). Treatment with telmisartan provided a comparable level of protection as compared with edaravone in all the parameters measured. Taken together, edaravone treatment ameliorates cardiac fibrosis and improves left ventricular function in the pressure overload rat model, potentially via suppressing the AT1 receptor-mediated signaling pathways. These data indicate that edaravone might be selected in combination with other existing drugs in preventing progression of cardiac dysfunction in heart failure.

Postconditioning attenuates coronary perivascular and interstitial fibrosis through modulating angiotensin II receptors and angiotensin-converting enzyme 2 after myocardial infarction.

BACKGROUND: Postconditioning (Postcon) is known to reduce infarct size. This study tested the hypothesis that Postcon attenuates the perivascular and interstitial fibrosis after myocardial infarction through modulating angiotensin II-activated fibrotic cascade. MATERIALS AND METHODS: Male Sprague-Dawley rats were subjected to 45-min coronary occlusion followed by 1 and 6 wk of reperfusion. Postcon was applied at the onset of reperfusion with four cycles of 10/10-s reperfusion-ischemia at the onset of reperfusion. Preconditioning (Precon) with two cycles of 5/5-min ischemia-reperfusion was applied before coronary occlusion. RESULTS: Postcon reduced angiotensin-converting enzyme protein and expression in the perivascular area and intermyocardium, coincident with the less-expressed angiotensin II receptor, type 1, enhanced angiotensin II receptor, type 2, and angiotensin converting enzyme 2. Postcon lowered the monocyte chemoattractant protein-1 and inhibited the populations of interstitial macrophages (60 ± 12 versus 84 ± 9.5 number per high-powered field [HPF] in control, P < 0.05). Along with these modulations, Postcon also downregulated transforming growth factor ß1 protein and inhibited proliferation of α-smooth muscle actin expressing myofibroblasts (41 ± 11 versus 79 ± 8.2 number per HPF in control, P < 0.05), consistent with downregulated phospho-Smad2 and phospho-Smad3. Furthermore, the synthesis of collagen I and III was attenuated, and the perivascular-interstitial fibrosis was inhibited by Postcon as demonstrated by reduced perivascular fibrosis ratio (0.6 ± 0.6 versus 1.6 ± 0.5 per HPF in control, P < 0.05) and smaller collagen-rich area (16 ± 4.7 versus 34 ± 9.2% per HPF in control, P < 0.05). Precon conferred a comparable level of protection as Postcon did in all parameters measured, suggesting protection trigged by this endogenous stimulation can be achieved when it was applied either before ischemia or after reperfusion. CONCLUSIONS: These results suggest that Postcon could be selected as an adjunctive intervention with other existing therapeutic drugs to treat the fibrosis-derived heart failure patients after myocardial infarction.

Recruitment of macrophages from the spleen contributes to myocardial fibrosis and hypertension induced by angiotensin II.

INTRODUCTION: The purpose of this study was to determine whether macrophages migrated from the spleen are associated with angiotensin II-induced cardiac fibrosis and hypertension. METHODS: Sprague-Dawley rats were subjected to angiotensin II infusion in vehicle (500 ng/kg/min) for up to four weeks. In splenectomy, the spleen was removed before angiotensin II infusion. In the angiotensin II AT1 receptor blockade, telmisartan was administered by gastric gavage (10 mg/kg/day) during angiotensin II infusion. The heart and aorta were isolated for Western blot analysis and immunohistochemistry. RESULTS: Angiotensin II infusion caused a significant reduction in the number of monocytes in the spleen through the AT1 receptor-activated monocyte chemoattractant protein-1. Comparison of angiotensin II infusion, splenectomy and telmisartan comparatively reduced the recruitment of macrophages into the heart. Associated with this change, transforming growth factor ß1 expression and myofibroblast proliferation were inhibited, and Smad2/3 and collagen I/III were downregulated. Furthermore, interstitial/perivascular fibrosis was attenuated. These modifications occurred in coincidence with reduced blood pressure. At week 4, invasion of macrophages and myofibroblasts in the thoracic aorta was attenuated and expression of endothelial nitric oxide synthase was upregulated, along with a reduction in aortic fibrosis. CONCLUSIONS: These results suggest that macrophages when recruited into the heart and aorta from the spleen potentially contribute to angiotensin II-induced cardiac fibrosis and hypertension.

Biological phosphorus removal in an extended ASM2 model: Roles of extracellular polymeric substances and kinetic modeling.

This paper presents the results of an extended ASM2 model for the modeling and calibration of the role of extracellular polymeric substances (EPS) in phosphorus (P) removal in an anaerobic-aerobic process. In this extended ASM2 model, two new components, the bound EPS (XEPS) and the soluble EPS (SEPS), are introduced. Compared with the ASM2, 7.71, 8.53, and 9.28% decreases in polyphosphate (polyP) were observed in the extended ASM2 in three sequencing batch reactors feeding with different COD/P ratios, indicating that 7.71-9.28% of P in the liquid was adsorbed by EPS. Sensitive analysis indicated that, five parameters were the significant influential parameters and had been chosen for further model calibration by using the least square method to simulate by MATLAB. This extended ASM2 has been successfully established to simulate the output variables and provides a useful reference for the mathematic simulations of the role of EPS in biological phosphorus removal process.