Leukocyte Ig-like receptor B4 (Lilrb4a) alleviates cardiac dysfunction and isoproterenol-induced arrhythmogenic remodeling associated with cardiac fibrosis and inflammation.

BACKGROUND: Heart failure (HF) is usually accompanied by the activation of the sympathetic nerve, and the excessive activation of the sympathetic nerve also promotes cardiac remodeling and cardiac dysfunction. In the isoproterenol (ISO) induced animal model, it is often accompanied by myocardial hypertrophy, fibrosis, and inflammation. Leukocyte immunoglobulin-like receptor B4a (Lilrb4a) is an immunosuppressive regulatory receptor and plays a vital role in cardiovascular disease. However, the effect of Lilrb4a on ventricular arrhythmias from ISO-induced mice model remains unclear. OBJECTIVE: The purpose of this study was to explore the role and molecular mechanism of Lilrb4a in ISO-induced arrhythmogenic remodeling. METHODS: Lilrb4a knockout mice and Lilrb4a overexpression mice were infused with ISO (15 mg/kg/24h, 4 weeks). Echocardiography and Histology were used to evaluate myocardial hypertrophy and cardiac structural remodeling. Surface ECG and Electrophysiological examination were used to evaluate cardiac electrical remodeling and the susceptibility to ventricular arrhythmias (VAs). qRT-PCR and Western Blotting were used to detect the expression levels of ion channel proteins and signal pathway proteins. RESULTS: The results discovered that ISO induced cardiac hypertrophy, fibrosis, and inflammation, and led to electrical remodeling and the occurrence of VAs. Lilrb4a alleviated cardiac structural and electrical remodeling and protected against the occurrence of VAs in ISO-induced mice by gain- or loss-of-function approaches. The mechanism is that Lilrb4a inhibited NF-kB signaling and p38 signaling activation medicated by TAK1. CONCLUSIONS: Lilrb4a alleviates cardiac dysfunction and isoproterenol-induced arrhythmogenic remodeling associated with cardiac fibrosis and inflammation through the regulation of NF-kB signaling and p38 signaling activation.

Ubiquitin specific protease 38 aggravates pathological cardiac remodeling by stabilizing phospho-TBK1.

Chronic pressure overload can cause pathological cardiac remodeling and eventually heart failure. The ubiquitin specific protease (USP) family proteins play a prominent role in regulating substrate protein degradation and cardiac structural and functional homeostasis. Although USP38 is expressed in the heart, uncertainty exists regarding the function of USP38 in pathological cardiac remodeling. We constructed and generated cardiac specific USP38 knockout mice and cardiac specific USP38 overexpression mice to assess the role of USP38 in pathological cardiac remodeling. Furthermore, we used co-immunoprecipitation (Co-IP) assays and western blot analysis to identify the molecular interaction events. Here, we reported that the expression of USP38 is significantly elevated under a hypertrophic condition in vivo and in vitro. USP38 deletion significantly mitigates cardiomyocyte enlargement in vitro and hypertrophic effect induced by pressure overload, while overexpression of USP38 markedly aggravates cardiac hypertrophy and remodeling. Mechanistically, USP38 interacts with TANK-binding kinase 1 (TBK1) and removes K48-linked polyubiquitination of TBK1, stabilizing p-TBK1 and promoting the activation of its downstream mediators. Overexpression of TBK1 in the heart of cardiac specific USP38 knockout mice partially counteracts the benefit of USP38 deletion on pathological cardiac remodeling. The TBK1 inhibitor Amlexanox significantly alleviates pressure overload induced-cardiac hypertrophy and myocardial fibrosis in mice with USP38 overexpression. Our results demonstrate that USP38 serves as a positive regulator of pathological cardiac remodeling and suggest that targeting the USP38-TBK1 axis is a promising treatment strategy for hypertrophic heart failure.

Anxiety disorder and cardiovascular disease: a two-sample Mendelian randomization study.

AIMS: Cardiovascular disease is the leading cause of death worldwide. Anxiety disorders are common psychiatric conditions associated with cardiovascular outcomes. This two-sample Mendelian randomization (MR) study investigated the causal relationship between anxiety disorders and coronary heart disease (CHD), myocardial infarction (MI), heart failure (HF), and atrial fibrillation (AF). METHODS: Single nucleotide polymorphisms (SNPs) associated with anxiety disorders (16 730 cases; 101 021 controls) were obtained from the UK Biobank genome-wide association study (GWAS). Cardiovascular outcome data were derived from the FinnGen study (CHD: 21 012 cases and 197 780 controls; MI: 12 801 cases and 187 840 controls; HF: 23 397 cases and 194 811 controls; and AF: 22 068 cases and 116 926 controls). Inverse variance weighted (IVW), MR-Egger, weighted median, simple mode, and weighted mode analyses examined causality. RESULTS: IVW analysis demonstrated significant causal relationships between anxiety disorders and increased risk of CHD [odds ratio (OR): 4.496; 95% confidence interval (CI): 1.777-11.378; P = 0.002], MI (OR: 5.042; 95% CI: 1.451-17.518; P = 0.011), and HF (OR: 3.255; 95% CI: 1.461-7.252; P = 0.004). No relationship was observed with AF (OR: 1.775; 95% CI: 0.612-5.146; P = 0.29). Other methods showed non-significant associations. Two-way analysis indicated no reverse causality. CONCLUSIONS: Anxiety disorders were causally associated with greater risk of CHD, MI, and HF but not AF among individuals of European descent. Further research on mediating mechanisms and in diverse populations is warranted.

Low-intensity pulsed ultrasound treatment mitigates ventricular arrhythmias via inhibiting microglia-mediated neuroinflammation in heart failure rat model.

BACKGROUND: Sympathetic overactivation plays an important role in heart failure (HF)-induced ventricular arrhythmias (VAs). Microglia-mediated neuroinflammation could contribute to sympathetic overactivation. A previous study demonstrated that low-intensity pulsed ultrasound (LIPUS) could inhibit neuroinflammation. However, whether LIPUS could attenuate HF-induced VAs via inhibiting microglia-mediated neuroinflammation remains largely unknown. METHODS: Forth Sprague-Dawley male rats were averagely randomized into four groups: CTL (control) group, CTL + LIPUS group, HF group and HF + LIPUS. Surgical ligation of the coronary artery was used for induction of HF. In vivo electrophysiological study was performed to check VAs susceptibility. Left stellate ganglion (LSG) neural activity and heart rate variability (HRV) were used to test sympathetic nerve activity. RESULTS: Compared to the HF group, LIPUS treatment significantly ameliorated HF-induced cardiac hypertrophy, fibrosis, and dysfunction. In addition, LIPUS treatment markedly inhibited HF-induced VAs susceptibility and reversed gap junction remodeling. LIPUS treatment obviously inhibited microglial activation and neuroinflammation in PVN, sympathetic hyperactivity in the LSG and proinflammatory cytokines releases in the ventricle. P2X7/NLRP3 signaling pathway may be involved in the anti-arrhythmic effect of LIPUS treatment following HF. CONCLUSIONS: Our data demonstrated that LIPUS treatment protected against HF-induced VAs via alleviating microglia-mediated neuroinflammation, sympathetic overactivation and proinflammatory cytokines releases through inhibiting P2X7/NLRP3 signaling. This study provides novel insight into the therapeutic potential of LIPUS.

maresin2 fine-tunes ULK1 O-GlcNAcylation to improve post myocardial infarction remodeling.

BACKGROUND: Myocardial infarction (MI) is one of the common causes of hospitalization and death all over the world. Maresin2 (MaR2), a specialized pro-solving mediator of inflammation, has been consolidated to be a novel cytokine fine-tuning inflammatory cascade. However, the precise mechanism is still unknown. Here, we demonstrated that maresin2 relieved myocardial damage via ULK1 O-GlcNAc modification during MI. METHODS: The myocardial infarction model was established by ligating the left anterior descending artery (LAD). Echocardiography, histopathology, transmission electron microscope, and Western blot were used to evaluate cardiac function and remodeling. Furthermore, primary neonatal rat cardiomyocytes (NRCMs) were cultivated, and immunoprecipitation (IP) assays were performed to explore the specific mechanism. RESULTS: As suggested, maresin2 treatment protected cardiac function and ameliorated adverse cardiac remodeling. Furthermore, we found that maresin2 facilitated autophagy and inhibited apoptosis under the modulation of O-GlcNAcylation-dependent ULK1 activation. Meanwhile, we discovered that maresin2 treatment ameliorated the inflammation of myocardial cells by inhibiting the interaction of TAK1 and TAB1. CONCLUSIONS: Maresin2 is likely to promote autophagy while relieving apoptosis and inflammation of myocardial cells, thereby exerting a protective effect on the heart after MI.

Bioengineering Approaches for the Pancreatic Tumor Organoids Research and Application.

Pancreatic cancer is a highly lethal form of digestive malignancy that poses significant health risks to individuals worldwide. Chemotherapy-based comprehensive treatment is the primary therapeutic approach for midlife and late-life patients. Nevertheless, the heterogeneity of the tumor and individual genetic backgrounds result in substantial variations in drug sensitivity among patients, rendering a single treatment regimen unsuitable for all patients. Conventional pancreatic cancer tumor organoid models are capable of emulating the biological traits of pancreatic cancer and are utilized in drug development and screening. However, these tumor organoids can still not mimic the tumor microenvironment (TME) in vivo, and the poor controllability in the preparation process hinders translation from essential drug screening to clinical pharmacological therapy. In recent years, many engineering methods with remarkable results have been used to develop pancreatic cancer organoid models, including bio-hydrogel, co-culture, microfluidic, and gene editing. Here, this work summarizes and analyzes the recent developments in engineering pancreatic tumor organoid models. In addition, the future direction of improving engineered pancreatic cancer organoids is discussed for their application prospects in clinical treatment.

Hydrological characteristics of the Bering Sea in the summer of 2019.

Based on the data of three CTD sections in the northern, northeastern and western Bering Sea of 2019 voyage of Chinese National Arctic Research Expedition (CHINARE), this paper analyzes and studies the hydrological characteristics of the water mass distribution, layered structure, and cline characteristics in different sea areas of the Bering Sea. The results indicate that the hydrological characteristics of the Bering Sea in the summer of 2019 are different from those in the past and that the water mass is warming in many locations. The maximum water temperature reaches 11.13 °C, and the maximum thickness of the warm water is about 32 m. The water mass composition and characteristics of the north-northeast-west sections are significantly different: the BL section has the highest salinity, while the BS section has the lowest salinity, and both the lowest temperature and the largest temperature variation appear in the BL section. The stratification characteristics in all sea areas are noteworthy. In the deep-water seas, there are three types of water masses: upper water (BSW), middle water (BIW) and deep water (BDW) from top to bottom, while two main water masses appear in the shelf waters with the Alaska Coastal Water (ACW) overlies the Bering Sea Shelf Water (BSW). Along the Bering Sea Slope Current (BSC), the water mass is essentially steady. Statically unstable hydrological inversion structure appears near the bottom of the three stations at the northern end of the BL section.

Screening Therapeutic Effects of MSC-EVs to Acute Lung Injury Model on A Chip.

Acute lung injury (ALI) is a lethal disease with high mortality rate, and its physiologically relevant models that could mimic human disease processes are urgently needed to study pathophysiology and predict drug efficacy. Here, this work presents a novel lipopolysaccharide (LPS) based ALI model on a microfluidic chip that reconstitutes an air-liquid interface lined by human alveolar epithelium and microvascular endothelium for screening the therapeutic effects of mesenchymal stem cells (MSC) derived extracellular vesicles (MSC-EVs) to the biomimetic ALI. The air-liquid interface is established by coculture of alveolar epithelium and microvascular endothelium on the opposite sides of the porous membrane. The functionalized architecture is characterized by integrate cell layers and suitable permeability. Using this biomimetic microsystem, LPS based ALI model is established, which exhibits the disrupted alveolar-capillary barrier, reduced transepithelial/transendothelial electrical resistance (TEER), and impaired expression of junction proteins. As a reliable disease model, this work examines the effects of MSC-EVs, and the data indicate the therapeutic potential of EVs for severe ALI. MSC-EVs can alleviate barrier disruption by restoring both the epithelial and endothelial barrier integrity. They hope this study can become a unique approach to study human pathophysiology of ALI and advance drug development.

Ovarian toxicity of e-cigarette liquids: Effects of components and high and low nicotine concentration e-cigarette liquid in vitro.

INTRODUCTION: Electronic cigarette use has become increasingly popular, with potential consequences for reproductive health. We aimed to investigate the effects of different components of e-liquid on the ovary and compare the impact of low nicotine concentration e-liquids (LN e-liquids) and high nicotine concentration e-liquids (HN e-liquids) on ovarian toxicity. METHODS: A total of 378 rat ovaries were divided into seven groups, including control (no intervention), nicotine (0.05 mg/mL), flavoring (0.25 µL/mL), propylene glycol (PG) (2.5 µL/mL), vegetable glycerin (VG) (2.0 µL/mL), LN e-liquid (0.05 mg nicotine + 0.25 µL flavoring + 2.5 µL PG + 2.0 µL VG + 0.25 µL distilled water/mL medium) and HN e-liquid groups (0.05 mg nicotine + 0.05 µL flavoring + 0.5 µL PG + 0.4 µL VG + 0.05 µL distilled water/mL medium). After three hours of in vitro culture, ovarian morphology, oxidation levels [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA)], and apoptosis levels [factor related apoptosis (Fas), Cyt-c, Caspase-9, Caspase-3] were analyzed. RESULTS: Our findings indicate that nicotine has limited impact on the ovary, while flavoring, PG, and VG all cause ovarian damage including morphological damage, disruption of oxidative balance and promotion of apoptosis, with VG having the most significant effect. Moreover, LN e-liquids may lead to more severe ovarian damage than HN e-liquids at an equal intake of total nicotine. CONCLUSIONS: Our study highlights that in e-liquid formula, nicotine has a limited effect on the ovaries, but flavoring, PG, and VG all cause damage to the ovaries, with VG the most damaging. At a consistent level of total nicotine intake, e-liquids with low nicotine concentrations cause more damage to the ovaries than those with high nicotine concentrations. These findings contribute to a better understanding of the impact of e-liquids on ovarian health and have important implications for public health policy.

Vericiguat alleviates ventricular remodeling and arrhythmias in mouse models of myocardial infarction via CaMKII signaling.

AIMS: Maladaptive ventricular remodeling is a major cause of ventricular arrhythmias following myocardial infarction (MI) and adversely impacts the quality of life of affected patients. Vericiguat is a new soluble guanylate cyclase (sGC) activator with cardioprotective properties. However, its effects on MI-induced ventricular remodeling and arrhythmias are not fully comprehended; hence, our research evaluated the effect of vericiguat on mice post-MI. MATERIALS AND METHODS: Mice were divided into four treatment groups: Sham, Sham+Veri, MI, and MI + Veri. For the MI groups and MI + Veri groups, the left anterior descending (LAD) coronary artery was occluded to induce MI. Conversely, the Sham group underwent mock surgery. Vericiguat was administered orally daily for 28 days to the Sham+Veri and MI + Veri groups. Additionally, H9c2 cells were cultured for further mechanistic studies. Assessment methods included echocardiography, pathological analysis, electrophysiological analysis, and Western blotting. KEY FINDINGS: Vericiguat reduced cardiac dysfunction and infarct size after MI. It also mitigated MI-induced left ventricular fibrosis and cardiomyocyte apoptosis. Vericiguat normalized the expression of ion channel proteins (Kv4.3, Kv4.2, Kv2.1, Kv1.5, Kv7.1, KCNH2, Cav1.2) and the gap junction protein connexin 43, reducing the susceptibility to ventricular arrhythmia. Vericiguat significantly inhibited MI-induced calcium/calmodulin-dependent protein kinase II (CaMKII) pathway activation in mice. SIGNIFICANCE: Vericiguat alleviated MI-induced left ventricular adverse remodeling and arrhythmias through modulation of the CamkII signaling pathway.

USP38 regulates inflammatory cardiac remodeling after myocardial infarction.

BACKGROUND: The inflammatory response and subsequent ventricular remodeling are key factors contributing to ventricular arrhythmias (VAs) after myocardial infarction (MI). Ubiquitin-specific protease 38 (USP38) is a member of the USP family, but the impact of USP38 in arrhythmia substrate generation after MI remains unclear. This study aimed to determine the role of USP38 in post-MI VAs and its underlying mechanisms. METHODS AND RESULTS: Surgical left descending coronary artery ligation was used to construct MI models. Morphological, biochemical, histological, and electrophysiological studies and molecular analyses were performed after MI on days 3 and 28. We found that the USP38 expression was remarkably increased after MI. Cardiac-conditional USP38 knockout (USP38-CKO) reduces the expression of the inflammatory marker CD68 as well as the inflammatory factors TNF-α and IL-1ß after MI, thereby alleviating advanced cardiac fibrosis, electrical remodeling, ion channel remodeling, and susceptibility to VAs. In contrast, cardiac-specific USP38 overexpression (USP38-TG) showed a significant opposite effect, exacerbating the early inflammatory response and cardiac remodeling after MI. Mechanistically, USP38 knockout inhibited activation of the TAK1/NF-κB signaling pathway after MI, whereas USP38 overexpression enhanced activation of the TAK1/NF-κB signaling pathway after MI. CONCLUSIONS: Our study confirms that USP38-CKO attenuates the inflammatory response, improves ventricular remodeling after myocardial infarction, and reduces susceptibility to malignant VA by inhibiting the activation of the TAK1/NF-κB pathway, with USP38-TG playing an opposing role. These results suggest that USP38 may be an important target for the treatment of cardiac remodeling and arrhythmias after MI.

5-Methoxytryptophan alleviates atrial structural remodeling in ibrutinib-associated atrial fibrillation.

Background: Ibrutinib is an effective and well-tolerated treatment for B-cell lymphomas but is associated with an increased risk of atrial fibrillation (AF) by altering the structure of the atrium. 5-Methoxytryptophan (5-MTP) inhibits inflammatory and fibrotic processes. This study aimed to determine the effects and mechanisms of 5-MTP on the underlying mechanisms of AF caused by ibrutinib. Methods: The effect of 5-MTP on ibrutinib-related AF was investigated in male Sprague Dawley rats using echocardiographic, electrophysiological, immunofluorescent, Masson staining, and molecular analyses. Rusults: The ibrutinib+5-MTP group showed (1) a lower incidence and shorter duration of AF and accelerated atrial conduction; (2) a decreased left atrial mass and left atrial diameter; (3) decreased myocardial fibrosis in the left atrium; (4) lower atrial inflammation; (5) increased sarcoplasmic reticulum Ca2+-ATPase 2a protein expression, decreased phosphorylation of phospholamban at Thr17, and decreased sodium/calcium exchanger 1 protein expression and phosphorylation of ryanodine receptor 2 at S2814; and (6) decreased phosphorylation of CaMKII expression. 5-MTP treatment markedly activated the PI3K-Akt signaling. Inhibiting PI3K-Akt signaling significantly reversed the protective effect of 5-MTP on ibrutinib-related AF. Conclusions: These findings suggest that 5-MTP administration decreases the vulnerability of ibrutinib-related AF mainly caused by ameliorated maladaptive left atrial remodeling and dysregulation of calcium handling proteins. Mechanistically, 5-MTP treatment markedly enhanced the activation of cardiac PI3K-Akt signaling.

Bioinspired nanogels as cell-free DNA trapping and scavenging organelles for rheumatoid arthritis treatment.

Excessive cell-free DNA (cfDNA) in the serum and synovium is considered a causative factor of rheumatoid arthritis (RA). Thus, cfDNA scavenging by using cationic polymers has been an effective therapeutic avenue, while these stratagems still suffer from systemic toxicity and unstable capture of cfDNA. Here, inspired by the biological charge-trapping effects and active degradation function of enzyme-containing organelles in vivo, we proposed a cationic peptide dendrimer nanogel with deoxyribonuclease I (DNase I) conjugation for the treatment of RA. Benefitting from their naturally derived peptide components, the resultant nanogels were highly biocompatible. More attractively, by tailoring them with a larger size and higher surface charge density, these cationic nanogels could achieve the fastest targeting capability, highest accumulation amounts, longer persistence time, and superior DNA scavenging capacity in inflamed joints. Based on these features, we have demonstrated that the organelle mimicking cationic nanogels could significantly down-regulate toll-like receptor (TLR)-9 signaling pathways and attenuate RA symptoms in collagen-induced arthritis mice. These results make the bioinspired DNase I conjugated cationic nanogels an ideal candidate for treating RA and other immune dysregulation diseases.

Columbianadin attenuates doxorubicin-induced cardiac injury, oxidative stress, and apoptosis via Sirt1/FOXO1 signaling pathway.

PURPOSE: Oxidative stress and apoptosis contribute to the pathological basis of doxorubicin (DOX)-induced cardiotoxicity. Columbianadin (CBN) is one of the main bioactive constituents isolated from the root of Angelica pubescens. Herein, we intended to explore the potential role and molecular basis of CBN in DOX-induced cardiotoxicity. METHODS: C57BL/6 mice were subjected to DOX (15 mg/kg/day, i.p.) to generate DOX-induced cardiotoxicity. CBN (10 mg/kg/day, i.p.) was administered for four week following DOX injection. RESULTS: DOX administered markedly dampened cardiac function, increased cardiac injury, excessive reactive oxygen species (ROS) production, and cardiomyocyte loss. These alterations induced by DOX significantly alleviated by CBN treatment. Mechanistically, our results demonstrated that the CBN exerts cardioprotection role against DOX by up-regulating silent information regulator 1 (Sirt1) and decreasing acetylation of forkhead box O1 (FOXO1). Moreover, Sirt1 inhibition with Ex-527 significantly blunt the beneficial effect of CBN on DOX-induced cardiotoxicity, including cardiac dysfunction, ROS, and apoptosis. CONCLUSION: Collectively, CBN attenuated oxidative stress and cardiomyocyte apoptosis in DOX-induced cardiotoxicity through maintaining Sirt1/FOXO1 signaling pathway. Our results demonstrated that CBN might be used to treat DOX-related cardiotoxicity.

Tirzepatide attenuates lipopolysaccharide-induced left ventricular remodeling and dysfunction by inhibiting the TLR4/NF-kB/NLRP3 pathway.

BACKGROUNDS: Sepsis-induced cardiac dysfunction is a leading cause of mortality in intensive care units. Tirzepatide, a dual glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist, possess cardio-protective, their effects on sepsis-induced cardiomyopathy remain unknown. METHODS: C57BL/6 mice received subcutaneous injections of tirzepatide once a day for 14 days before subjected to LPS challenge for 12 h. LPS-induced cardiac dysfunction and its potential mechanisms were estimated by pathological analysis, echocardiographic measurement, electrocardiography, langendorff-perfused heart and molecular analysis. RESULTS: Pretreatment with tirzepatide attenuates LPS-induced cardiac dysfunction. tirzepatide remarkably reduces LPS-mediated inflammatory responses by inhibiting  the cardiac protein levels of TNF-α, IL-6, and IL-1B in mice. Interestingly, tirzepatide administration also improves cardiomyocytes apoptosis caused by LPS treatment. Furthermore, the protective roles of irzepatide against LPS-mediated increased inflammatory responses and decreased cardiomyocytes apoptosis are partially blunted by inhibiting TLR4/NF-kB/NLRP3 inflammation signaling. In addition, tirzepatide reduce the susceptibility ventricular arrhythmia in LPS-treated mice. CONCLUSION: In brief, tirzepatide attenuates LPS-induced left ventricular remodeling and dysfunction by inhibiting the TLR4/NF-kB/NLRP3 pathway.

[Retracted] TGF­ß1 induces peritoneal fibrosis by activating the Smad2 pathway in mesothelial cells and promotes peritoneal carcinomatosis.

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that the fluorescence microscopy data shown in Fig. 6A and B were strikingly similar to data appearing in different form in Fig. 7 in a previously published paper [Lv Z­D, Na D, Liu F­N, Du Z­M, Sun Z, Li Z, Ma X­Y, Wang Z­N and Xu H­M: Induction of gastric cancer cell adhesion through transforming growth factor­beta1­mediated peritoneal fibrosis. J Exp Clin Cancer Res 29: 139, 2010], which featured some of the same authors, although the data were shown to portray results obtained under different experimental conditions. Furthermore, the data in Fig. 7A for the 'TGF­ß1' and the 'TGF­ß1 + siRNAcon' experiments contained an overlapping section, such that these data appeared to have been derived from the same original source, even though they were intended to show the results from differently performed experiments. Owing to the fact that the contentious data in the above article had already been published prior to its submission to International Journal of Molecular Medicine, and due to a lack of overall confidence in the presented data, the Editor has decided that this paper should be retracted from the Journal. After having been in contact with the authors, they accepted the decision to retract the paper. The Editor apologizes to the readership for any inconvenience caused. [International Journal of Molecular Medicine 29: 373­379, 2012; DOI: 10.3892/ijmm.2011.852].

In Situ Sprayed Difunctional Gel Avoiding Microenvironments Limitations to Treat Pressure Ulcers.

How to avoid the microenvironment limitations in the therapeutic process of pressure ulcers is still challenging. The development of a functional gel can kill bacteria and scavenge reactive oxygen species (ROS), which is urgently required in the therapeutic process of pressure ulcers. Herein, an in situ sprayed gel is developed with silver nanoparticles (AgNPs) and polydopamine (PDA) NPs (APG) to obviate microenvironment restrictions in treating pressure ulcers. The gel is constructed by spraying sodium alginate solution and CaCl2 solution. AgNPs serve as an antibacterial agent in the formed gel, which can effectively cause bacterial inactivation and show more than 5 log (>99.999%) bacterial killing efficiency against methicillin-resistant S. aureus (MRSA), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli) in vitro. Meanwhile, PDA NPs serve as the antioxidative agent in the formed gel, which can facilitate the elimination of ROS to address the high ROS problem in wound microenvironment. Based on these features, it is demonstrated through cell and animal experiments that the AgNPs and PDA NPs incorporated gel can realize the effective treatment of MRSA-infected and hydrogen peroxide (H2 O2 )-sensitized pressure ulcers. It is believed that the designed system by a simple spray-coating approach can provide a new therapeutic strategy in biomedical areas.