Epigenetic Switch at Atp2a2 and Myh7 Gene Promoters in Pressure Overload-Induced Heart Failure

Re-induction of fetal genes and/or re-expression of postnatal genes represent hallmarks of pathological cardiac remodeling, and are considered important in the progression of the normal heart towards heart failure (HF). Whether epigenetic modifications are involved in these processes is currently under investigation. Here we hypothesized that histone chromatin modifications may underlie changes in the gene expression program during pressure overload-induced HF. We evaluated chromatin marks at the promoter regions of the sarcoplasmic reticulum Ca2+ATPase (SERCA-2A) and β-myosin-heavy chain (β-MHC) genes (Atp2a2 and Myh7, respectively) in murine hearts after one or eight weeks of pressure overload induced by transverse aortic constriction (TAC). As expected, all TAC hearts displayed a significant reduction in SERCA-2A and a significant induction of β-MHC mRNA levels. Interestingly, opposite histone H3 modifications were identified in the promoter regions of these genes after TAC, including H3 dimethylation (me2) at lysine (K) 4 (H3K4me2) and K9 (H3K9me2), H3 trimethylation (me3) at K27 (H3K27me3) and dimethylation (me2) at K36 (H3K36me2). Consistently, a significant reduction of lysine-specific demethylase KDM2A could be found after eight weeks of TAC at the Atp2a2 promoter. Moreover, opposite changes in the recruitment of DNA methylation machinery components (DNA methyltransferases DNMT1 and DNMT3b, and methyl CpG binding protein 2 MeCp2) were found at the Atp2a2 or Myh7 promoters after TAC. Taken together, these results suggest that epigenetic modifications may underlie gene expression reprogramming in the adult murine heart under conditions of pressure overload, and might be involved in the progression of the normal heart towards HF

Akap1 deficiency promotes mitochondrial aberrations and exacerbates cardiac injury following permanent coronary ligation via enhanced mitophagy and apoptosis

A-kinase anchoring proteins (AKAPs) transmit signals cues from seven-transmembrane receptors to specific sub-cellular locations. Mitochondrial AKAPs encoded by the Akap1 gene have been shown to modulate mitochondrial function and reactive oxygen species (ROS) production in the heart. Under conditions of hypoxia, mitochondrial AKAP121 undergoes proteolytic degradation mediated, at least in part, by the E3 ubiquitin ligase Seven In-Absentia Homolog 2 (Siah2). In the present study we hypothesized that Akap1 might be crucial to preserve mitochondrial function and structure, and cardiac responses to myocardial ischemia. To test this, eight-week-old Akap1 knockout mice (Akap1(-/-)), Siah2 knockout mice (Siah2(-/-)) or their wild-type (wt) littermates underwent myocardial infarction (MI) by permanent left coronary artery ligation. Age and gender matched mice of either genotype underwent a left thoracotomy without coronary ligation and were used as controls (sham). Twenty-four hours after coronary ligation, Akap1(-/-) mice displayed larger infarct size compared to Siah2(-/-) or wt mice. One week after MI, cardiac function and survival were also significantly reduced in Akap1(-/-) mice, while cardiac fibrosis was significantly increased. Akap1 deletion was associated with remarkable mitochondrial structural abnormalities at electron microscopy, increased ROS production and reduced mitochondrial function after MI. These alterations were associated with enhanced cardiac mitophagy and apoptosis. Autophagy inhibition by 3-methyladenine significantly reduced apoptosis and ameliorated cardiac dysfunction following MI in Akap1(-/-) mice. These results demonstrate that Akap1 deficiency promotes cardiac mitochondrial aberrations and mitophagy, enhancing infarct size, pathological cardiac remodeling and mortality under ischemic conditions. Thus, mitochondrial AKAPs might represent important players in the development of post-ischemic cardiac remodeling and novel therapeutic targets

LA DELEZIONE DELL'E3 UBIQUITINA LIGASI SIAH2 RIDUCE L'APOPTOSI INDOTTA DA IPOSSIA E L'INFARCT SIZE DOPO LEGATURA DELL'ARTERIA CORONARIA

La proteina Seven In Absentia Homolog 2 (siah2) è una E3 ubiquitina ligasi la cui espressione è indotta in condizioni di ipossia. E’ stato valutato il ruolo della proteina siah2 in condizioni di ischemia tissutale, utilizzando topi knock-out per il gene siah2 (siah2-/-) e topi wild-type (wt), in un modello murino di infarto miocardico acuto (MI) e in condizioni di ipossia cellulare in Fibroblasti Embrionali Murini (MEF). Dopo stimolo ipossico di 12 ore, la delezione genetica di siah2 aumentava i livelli cellulari della proteina di ancoraggio mitocondriale AKAP121, migliorava la funzione mitocondriale e riduceva significativamente l’apoptosi cellulare nei MEF. In vivo l’assenza della proteina non alterava la funzione cardiaca in condizioni basali, tuttavia 4 settimane dopo infarto miocardico i topi privi del gene siah2 mostravano un miglioramento significativo della funzione ventricolare, della sopravvivenza e dell’entità del rimodellamento cardiaco post ischemico. In conclusione, questo studio dimostra per la prima volta il ruolo cruciale svolto da Siah2 nella risposta cardiaca al danno ischemico, identificando un nuovo potenziale target molecolare per la cardiopatia ischemica

Deployment of a Novel Organic Acid Compound Disinfectant against Common Foodborne Pathogens

Background: The disinfection process represents an important activity closely linked to the removal of micro-organisms in common processing systems. Traditional disinfectants are often not sufficient to avoid the spread of food pathogens; therefore, innovative strategies for decontamination are crucial to countering microbial transmission. This study aims to assess the antimicrobial efficiency of tetrapotassium iminodisuccinic acid salt (IDSK) against the most common pathogens present on surfaces, especially in food-borne environments. Methods: IDSK was synthesized from maleic anhydride and characterized through nuclear magnetic resonance (NMR) spectroscopy (both 1H-NMR and 13C-NMR), thermogravimetric analysis (TGA) and Fourier Transform Infrared (FTIR) spectroscopy. The antibacterial activity was performed via the broth microdilution method and time-killing assays against Escherichia coli, Staphylococcus aureus, Salmonella enterica, Enterococcus faecalis and Pseudomonas aeruginosa (IDSK concentration range: 0.5–0.002 M). The biofilm biomass eradicating activity was assessed via a crystal violet (CV) assay. Results: The minimum inhibitory concentration (MIC) of IDSK was 0.25 M for all tested strains, exerting bacteriostatic action. IDSK also reduced biofilm biomass in a dose-dependent manner, reaching rates of about 50% eradication at a dose of 0.25 M. The advantages of using this innovative compound are not limited to disinfecting efficiency but also include its high biodegradability and its sustainable synthesis. Conclusions: IDSK could represent an innovative and advantageous disinfectant for food processing and workers’ activities, leading to a better quality of food and safer working conditions for the operators

The influence of microclimate conditions on ozone disinfection efficacy in working places

In recent years, the sanitization of environments, devices, and objects has become mandatory to improve human and environmental safety, in addition to individual protection and prevention measures. International studies considered ozone one of the most useful and easy sanitization methods for indoor environments, especially hospital environments that require adequate levels of disinfection. The purpose of this work was to evaluate the microclimate influence on sanitizing procedure for indoor settings with ozone, to prevent infections and ensure the safe use of the environments. The concentration of ozone was measured during sanitization treatment and estimation of microorganisms’ survival on the air and different contaminated plates after the sanitization operations were performed. The results demonstrated a significant reduction in the microbial count that always fell below the threshold value in different conditions of distance, temperature, and relative humidity

Comparative analysis of peracetic acid (PAA) and permaleic acid (PMA) in disinfection processes

The growing demand to reduce chlorine usage and control disinfection byproducts increased the development of new strategies in wastewater treatments. Organic peracids are increasingly attracting interest in disinfection activities as a promising alternative to chlorine and chlorine-based agents. In this study, we assessed the antimicrobial properties against escherichia coli(E. coli)and staphylococcus aureus(S. aureus) of a new organic peracid, permaleic acid (PMA) compared with the reference peracetic acid (PAA). Disinfectant properties were evaluated by i) disk diffusion agar, ii) broth microdilution, iii) antibiofilm properties. PMA demonstrated a 10- and 5-fold decrease inthe microbial inhibitory concentration (MIC) value against E. coli andS. aureus respectively,comparedto PAA. Results showed greater efficacy of PMA regarding wastewater (WW) and treated wastewater (TWW)disinfection at low concentrations. Furthermore, the biofilm degradation ability was only observed followingPMA treatment, for both strains. Bacterial regrowth from biofilm matrix after PAA and PMA disinfection, in theabsence and presence of organic matter, was evaluated. PMA was more efficient than PAA to prevent the regrowth of planktonic cells ofS. aureusandE. coli. After PAA and PMA treatment, in the presence of organic matter,the bacterial regrowth inhibition was maintained up to 10 and 5 g/L, respectively. Based on these results, PMA could be used as a valid alternative to the currently used disinfection methods

Protective role of Uncoupling Protein 3 under hypoxic conditions in vitro and in the pathogenesis of post-ischemic cardiac remodelling in vivo

Uncoupling protein 3 (UCP3) is a member of the mitochondrial anion carrier superfamily, uncoupling mitochondrial respiration and thus decreasing the energy status. In this study we investigated the effects of UCP3 genetic deletion on mitochondrial function, cell survival and cardiac remodelling in vivo. In order to test whether UCP3 deletion was associated with mitochondrial damage, increased reactive oxygen species (ROS) production and apoptotic cell death, murine embryonic fibroblasts (MEFs) were isolated from WT and UCP3 knockout mice (ucp3–/–). Compared to WT, under both normoxic and hypoxic conditions, ucp3–/– MEFs exhibited significantly reduced mitochondrial dehydrogenase activity (WT: 1.2±0.02, ucp3–/–: 0.3±0.02, p<0.05) and increased mitochondrial ROS generation assayed by mitosox staining. Furthermore, apoptotic cell death was significantly increased in ucp3–/– MEFs as shown by TUNEL assay under basal conditions (WT: 8.5±0.15, ucp3–/–: 12.6±0.29, p<0.05) and annexin-propidium iodide double staining under normoxic or hypoxic conditions (normoxia, WT: 0.3±0.1, ucp3–/–: 3.0±0.2; 30 min hypoxia, WT: 0.99±0.3, ucp3–/–: 2.9±0.6; p<0.05). In order to test the role of UCP3 on cardiac remodelling in vivo, physiological hypertrophy by swimming and acute myocardial infarction (MI) by surgical coronary ligation were induced in wild-type (WT) and ucp3–/– mice. After 5 weeks of swimming training, cardiac structure and function in ucp3–/– mice was not statistically different from WT mice. In contrast, 8 weeks after MI, cardiac function was significantly decreased in ucp3–/– mice compared to the WT (% fractional shortening, WT: 42.7±3; ucp3–/–: 24.4±3, p<0.05; infarct size cm2, WT: 0.19±0.03; ucp3–/–: 0.21±0.2, not significant), and this was associated with increased fibrosis. Importantly, survival rates of ucp3–/– mice after MI were significantly lower than WT (p<0.05; {chi}2=4.35). Taken together, our data indicate for the first time the protective role of UCP3 under hypoxic conditions, and suggest that UCP3 might represent a novel important player in the pathogenesis of post-ischemic cardiac remodelling in viv