ID: 137: GRK2 INHIBITION REDUCES POST-MYOCARDIAL INFARCTION CARDIAC FIBROBLAST MEDIATED ADVERSE REMODELING

Objectives

Remote (non-infarct) territory fibrosis is a significant cause of post-infarction heart failure (HF). We have previously shown that increased G protein-coupled receptor kinase-2 (GRK2) activity in adult human cardiac fibroblasts (CF) isolated from failing hearts is an important mechanism of cardiac fibrosis through uncoupling β-adrenergic receptor (β-AR) signaling. This study investigates the potential therapeutic role of GRK2 inhibition on CF biology in vivo.

Methods

Adult male rats underwent LAD ligation to induce post-MI HF. Left ventricular (LV) function was assessed by echocardiography. Myocardial fibrosis was quantitated by histologic staining. LV CF were isolated and cultured. GRK2 was inhibited by intra-coronary adenoviral-mediated delivery of a GRK2 inhibitor (Ad-GRK2ct) immediately following LAD ligation (n=11). Control rats received a null adenovirus (n=10). Animals were studied prior to and 12 weeks post-MI and adenoviral delivery.

Results

There was a significant decline in LV function at 12 weeks post-MI which [Fractional shortening: 0.35±0.01 vs. 0.52±0.01, p<0.01]. There was significant increase in remote territory (non-infarct area) fibrosis at 12 weeks post-MI compared to control [12±1% vs. 2±1% fibrosis, p<0.05], consistent with adverse remodeling. Additionally, collagen synthesis was significantly upregulated in isolated CF 12 weeks post-MI compared to control CF [3559±760 vs. 1029±45 cmp/mg protein, p<0.02]. At 12 weeks post-MI, GRK2 activity was increased 1.4-fold [p<0.01]. There was a 42% decrease in intracellular cAMP [p<0.05] and loss of b-agonist (isoproterenol)-stimulated inhibition of collagen synthesis characteristic of normal CF, indicating uncoupling of β-AR signaling post-MI. Adenoviral mediated overexpression of GRK2ct, GRK2 inhibitor, in vitro in the cultured CF post-MI led to a 50% decrease in aSMA expression (p<0.01) as well as a significant decreased collagen expression and synthesis compared to null adenovirus (Ad-Null) control [1928±126 vs. 2611±213 cmp/mg protein, p<0.05], restoring the control CF phenotype. Intra-coronary delivery of Ad-GRK2ct following MI significantly reduced post-MI LV dysfunction vs. Ad-Null as measured by improved fractional shortening [0.42±0.01 vs. 0.30±0.02, p<0.01] and ejection fraction [72±1% vs. 57±2%, p<0.03]. Ad-GRK2ct also decreased peri-infarct and remote territory fibrosis by 60% [p<0.03]. Consistent with these findings, Ad-GRK2ct resulted in an over 25% decreased in α-SMA, collagen I, and collagen III expression in CF isolated 12 weeks post-MI vs. Ad-Null [p<0.04] providing evidence of decreased post-MI CF activation and myofibroblast transformation with Ad-GRK2ct.

Conclusions

Uncoupling of β-adrenergic signaling in CF via increased GRK2 appears to be a key mechanism of post-MI fibrosis. Targeted inhibition of GRK2 and restoration of b-adrenergic signaling/cAMP production in CF may represent a novel therapeutic approach to prevent pathological fibrosis and maladaptive remodeling.

Impact of carbon to nitrogen ratio and aeration regime on mainstream deammonification

While deammonification of high-strength wastewater in the sludge line of sewage treatment plants has become well established, the potential cost savings spur the development of this technology for mainstream applications. This study aimed at identifying the effect of aeration and organic carbon on the deammonification process. Two 10 L sequencing bath reactors with different aeration frequencies were operated at 25°C. Real wastewater effluents from chemically enhanced primary treatment and high-rate activated sludge process were fed into the reactors with biodegradable chemical oxygen demand/nitrogen (bCOD/N) of 2.0 and 0.6, respectively. It was found that shorter aerobic solids retention time (SRT) and higher aeration frequency gave more advantages for aerobic ammonium-oxidizing bacteria (AerAOB) than nitrite oxidizing bacteria (NOB) in the system. From the kinetics study, it is shown that the affinity for oxygen is higher for NOB than for AerAOB, and higher dissolved oxygen set-point could decrease the affinity of both AerAOB and NOB communities. After 514 days of operation, it was concluded that lower organic carbon levels enhanced the activity of anoxic ammonium-oxidizing bacteria (AnAOB) over denitrifiers. As a result, the contribution of AnAOB to nitrogen removal increased from 40 to 70%. Overall, a reasonably good total removal efficiency of 66% was reached under a low bCOD/N ratio of 2.0 after adaptation.

Comparison of full-mouth disinfection and quadrant-wise scaling in the treatment of adult chronic periodontitis: a systematic review and meta-analysis

Scaling and root planing are widely considered as effective methods for treating chronic periodontitis. A meta-analysis published in 2008 showed no statistically significant differences between full-mouth disinfection (FMD) or full-mouth scaling and root planing (FMS) and quadrant scaling and root planing (Q-SRP). The FMD approach only resulted in modest additional improvements in several indices. Whether differences exist between these two approaches requires further validation. Accordingly, a study was conducted to further validate whether FMD with antiseptics or FMS without the use of antiseptics within 24 h provides greater clinical improvement than Q-SRP in patients with chronic periodontitis. Medline (via OVID), EMBASE (via OVID), PubMed and CENTRAL databases were searched up to 27 January 2015. Randomized controlled trials comparing FMD or FMS with Q-SRP after at least 3 mo were included. Meta-analysis was performed to obtain the weighted mean difference (WMD), together with the corresponding 95% confidence intervals. Thirteen articles were included in the meta-analysis. The WMD of probing pocket depth reduction was 0.25 mm (p < 0.05) for FMD vs. Q-SRP in single-rooted teeth with moderate pockets, and clinical attachment level gain in single- and multirooted teeth with moderate pockets was 0.33 mm (p < 0.05) for FMD vs. Q-SRP. Except for those, no statistically significant differences were found in the other subanalyses of FMD vs. Q-SRP, FMS vs. Q-SRP and FMD vs. FMS. Therefore, the meta-analysis results showed that FMD was better than Q-SRP for achieving probing pocket depth reduction and clinical attachment level gain in moderate pockets. Additionally, regardless of the treatment, no serious complications were observed. FMD, FMS and Q-SRP are all effective for the treatment of adult chronic periodontitis, and they do not lead to any obvious discomfort among patients. Moreover, FMD had modest additional clinical benefits over Q-SRP, so we prefer to recommend FMD as the first choice for the treatment of adult chronic periodontitis.

Biological significance of miR-126 expression in atrial fibrillation and heart failure

We investigated the biological significance of microRNA-126 (miR-126) expression in patients with atrial fibrillation (AF) and/or heart failure (HF) to examine the possible mechanism of miR-126-dependent AF and development of HF. A total of 103 patients were divided into three groups: AF group (18 men and 17 women, mean age: 65.62±12.72 years), HF group (17 men and 15 women, mean age: 63.95±19.71 years), and HF-AF group (20 men and 16 women, mean age: 66.56±14.37 years). Quantitative real-time PCR was used to measure relative miR-126 expression as calculated by the 2-ΔΔCt method. miR-126 was frequently downregulated in the 3 patient groups compared with controls. This reduction was significantly lower in permanent and persistent AF patients than in those with paroxysmal AF (P<0.05, t-test). Moreover, miR-126 expression was markedly lower in the HF-AF group compared with the AF and HF groups. The 3 patient groups had higher N-terminal prohormone brain natriuretic peptide (NT-proBNP) levels, lower left ventricular ejection fraction (LVEF), larger left atrial diameter, and higher cardiothoracic ratio compared with controls. There were significant differences in NT-proBNP levels and LVEF among the AF, HF, and HF-AF groups. Pearson correlation analysis showed that relative miR-126 expression was positively associated with LVEF, logarithm of NT-proBNP, left atrial diameter, cardiothoracic ratio, and age in HF-AF patients. Multiple linear regression analysis showed that miR-126 expression was positively correlated with LVEF, but negatively correlated with the logarithm of NT-pro BNP and the cardiothoracic ratio (all P<0.05). Serum miR-126 levels could serve as a potential candidate biomarker for evaluating the severity of AF and HF. However, to confirm these results, future studies with a larger and diverse patient population are necessary.

Effects of TNF-α on Cementoblast Differentiation, Mineralization, and Apoptosis

Tumor necrosis factor–α (TNF-α) is involved in various inflammatory processes, including periodontitis. Although the influences of TNF-α on periodontal ligament fibroblasts and osteoblasts have been widely documented, its effects on cementoblasts, the cells responsible for cementum production, remain largely unknown. In this study, we found that TNF-α suppressed the mineralization ability of cementoblasts by inhibiting differentiation and inducing apoptosis. Various signaling pathways, such as p53, PP2AC, p38, Erk1/2, JNK, PI3K-Akt, and NF-κB, were activated during this process. The use of a specific inhibitor and siRNA transfection confirmed that the effects of TNF-α on differentiation and apoptosis in cementoblasts were partially abrogated by inhibiting p53 activity. By contrast, the effects of TNF-α were even exacerbated by the inhibition of the p38, Erk1/2, JNK, PI3K-Akt, and NF-κB pathways. Moreover, p53 activity was further enhanced by blocking the p38, Erk1/2, JNK, and PI3K-Akt signaling pathways. Taken together, these results suggested that the differentiation inhibition and apoptosis in cementoblasts induced by TNF-α were partially dependent on p53 activity. The p38, Erk1/2, JNK, PI3K-Akt, and NF-κB pathways were also activated but acted as balancing players to limit rather than conduct the negative effects of TNF-α. These balancing effects were dependent, or at least partially dependent, on p53, except for the NF-κB pathway.

Relationship between genetic polymorphisms in MCP-1, CCR-2, and non-small-cell lung cancer in the Han nationality of Northern China

Lung cancer is a common malignant tumor worldwide and is now the leading cause of cancer-related deaths. Monocyte chemoattractant protein 1 (MCP-1) and its receptor chemokine receptor 2 (CCR-2) are important chemokines. We examined the polymorphisms of 338 unrelated patients with non-small cell lung carcinoma (NSCLC) and 200 unrelated healthy controls of Han nationality in Northern China using polymerase chain reaction-restriction fragment length polymorphism. We found a significant increase in the frequency of the MCP-1 AA genotype [0.293 vs 0.195, odds ratio (OR) = 1.71, 95% confidence interval (CI) = 1.13-2.60] and a significant decrease in the frequency of the GG genotype (0.290 vs 0.41, OR = 0.64, 95%CI = 0.47-0.87) in NSCLC patients compared to controls. The frequencies of AA-ww (0.151 vs 0.090, P = 0.041, OR = 1.80, 95%CI = 1.33-2.43) and AA-wm (0.136 vs 0.080, P = 0.049, OR = 1.81, 95%CI = 1.01-3.27) were higher in lung cancer patients than in healthy controls; the frequency of GG-wm (0.121 vs 0.190, P = 0.030, OR = 0.60, 95%CI = 0.38-0.95) was lower in lung cancer patients than in healthy controls. Based on these results, the polymorphism in MCP-1 may be correlated with the development of NSCLC in the Han nationality of Northern China. However, the polymorphism in CCR-2 is not involved in NSCLC.

Neither insufficiency nor overexpression of sac1 affects the accumulation of Aβ42 in Drosophila expressing Ab42

OBJECTIVE

We investigated the effects of genetic down- and up-regulation of sac1 expression on Aβ42 accumulation and the associated neural deficits in flies with direct expression of arctic mutant Aβ42 (Aβarc) in the neurons of GF pathway.

MATERIALS AND METHODS

We genetically down-regulated and up-regulated the level of sac1, encoding a major phosphoinositide phosphatases in a disease model, in which arctic mutant Aβ42 is directly expressed in the neurons of a neural pathway of adult fruit flies.

RESULTS

We conducted a time-course analysis of Aβ42 level in the model and found an age-dependent elevation of Aβ42 accumulation, closely correlated to the age-dependent decline of climbing ability in the model flies. Neither sac1 insufficiency nor sac1 over-expression significantly changed the three phenotypes.

CONCLUSIONS

We found that the alterations of sac1 expression did not change Aβ42 accumulation and neural deficits in the model.

Sorafenib combined with percutaneous radiofrequency ablation for the treatment of medium-sized hepatocellular carcinoma

OBJECTIVE

Sorafenib, an oral multikinase inhibitor, is the proved therapy method for patients with advanced hepatocellular carcinoma (HCC). Based on heat delivery, Radiofrequency ablation (RFA) has been found to achieve complete neoplasm necrosis. It is the most widely performed percutaneous therapy for HCC. However, Study associated combined Sorafenib with RFA therapy for patients with advanced HCC has never been reported. The aim of present study is to explore the efficacy and safety of sorafenib combined with RFA therapy for the patients with medium-sized HCC.

PATIENTS AND METHODS

A total of 62 patients diagnosed as HCC were involved in this study. All patients were randomly assigned to sorafenib and RFA (n=30) or RFA-alone (n=32) treatment groups. Treatment outcomes, including recurrence rates, time to progression (TTP) and adverse reactions induced by sorafenib were observed and recorded to assess the efficacy and safety of the combination method.

RESULTS

During the overall follow-up period, the recurrence rate of the combination subgroup was 56.7% (17/30), and that of the RFA-alone subgroup was 87.5% (28/32) (p < 0.01). The median TTP was 17.0 months in the combination therapy vs. 6.1 months in the RFA-alone (p < 0.05). Hand-foot skin reactions were reported by 83.3% (25/30) of patients and 46.7% (14/30) reported diarrhea while the most adverse events (AEs) were mild to moderate in the combination subgroup.

CONCLUSIONS

Sorafenib combined with RFA significantly decreased recurrence rates and prolonged the survival time of medium-sized HCC patients. The combination therapy is safer and more effective than the control without unexpected side effects. Furthermore, the earlier application, the better results were.

Dimethyl fumarate attenuates 6-OHDA-induced neurotoxicity in SH-SY5Y cells and in animal model of Parkinson's disease by enhancing Nrf2 activity

Oxidative stress is central to the pathology of several neurodegenerative diseases, including Parkinson's disease (PD), and therapeutics designed to enhance antioxidant potential could have clinical value. In this study, we investigated whether dimethyl fumarate (DMF) has therapeutic effects in cellular and animal model of PD, and explore the role of nuclear transcription factor related to NF-E2 (Nrf2) in this process. Treatment of animals and dopaminergic SH-SY5Y cells with DMF resulted in increased nuclear levels of active Nrf2, with subsequent upregulation of antioxidant target genes. The cytotoxicity of 6-hydroxydopamine (6-OHDA) was reduced by pre-treatment with DMF in SH-SY5Y cells. The increase in the reactive oxygen species caused by 6-OHDA treatment was also attenuated by DMF in SH-SY5Y cells. The neuroprotective effects of DMF against 6-OHDA neurotoxicity were dependent on Nrf2, since treatment with Nrf2 siRNA failed to block against 6-OHDA neurotoxicity and induce Nrf2-dependent cytoprotective genes in SH-SY5Y cells. In vivo, DMF oral administration was shown to upregulate mRNA and protein levels of Nrf2 and Nrf2-regulated cytoprotective genes, attenuate 6-OHDA induced striatal oxidative stress and inflammation in C57BL/6 mice. Moreover, DMF ameliorated dopaminergic neurotoxicity in 6-OHDA-induced PD animal models as evidenced by amelioration of locomotor dysfunction, loss in striatal dopamine, and reductions in dopaminergic neurons in the substantia nigra and striatum. Taken together, these data strongly suggest that DMF may be beneficial for the treatment of neurodegenerative diseases like PD.

Phase I ficlatuzumab monotherapy or with erlotinib for refractory advanced solid tumours and multiple myeloma

BACKGROUND

Ficlatuzumab, a humanised hepatocyte growth factor (HGF) IgG1κ inhibitory monoclonal antibody, was evaluated for recommended phase II dose (RP2D), safety, pharmacokinetics (PKs), antidrug antibody (ADA), pharmacodynamics (PDs) and antitumour activity as monotherapy or combined with erlotinib.

METHODS

Patients with solid tumours received ficlatuzumab 2, 5, 10 or 20 mg kg(-1) intravenously every 2 weeks (q2w). Additional patients were treated at the RP2D erlotinib.

RESULTS

Forty-one patients enrolled at doses ⩽20 mg kg(-1). Common adverse events (AEs) included peripheral oedema, fatigue and nausea. Three patients experienced grade ⩾3 treatment-related hyperkalaemia/hypokalaemia, diarrhoea or fatigue. Best overall response (44%) was stable disease (SD); median duration was 5.5 months (0.4-18.7 months). One patient has been on therapy with SD for >4 years. Pharmacokinetics of ficlatuzumab showed low clearance (0.17-0.26 ml h(-1) kg(-1)), a half-life of 6.8-9.4 days and dose-proportional exposure. Ficlatuzumab/erlotinib had no impact on the PK of either agent. No ADAs were detected. Ficlatuzumab increased serum HGF levels.

CONCLUSIONS

Recommended phase II dose is 20 mg kg(-1) q2w for ficlatuzumab monotherapy or with erlotinib. Preliminary antitumour activity and manageable AEs were observed. Pharmacokinetics were dose-proportional and consistent with other IgG therapeutics. Ficlatuzumab was not immunogenic, and serum HGF was a potential PD marker.

Efficacy and safety of micafungin for the prophylaxis of invasive fungal infection during neutropenia in children and adolescents undergoing allogeneic hematopoietic SCT

The objective of this study was to evaluate the efficacy and safety of micafungin for the prevention of invasive fungal infection (IFI) during the neutropenic phase of allogeneic hematopoietic SCT (allo-HSCT) in children and adolescents. This was a prospective, multicenter, open-label, single-arm study. Micafungin was administered i.v. at a dose of 1 mg/kg/day (max 50 mg) from the beginning of conditioning until neutrophil engraftment. Treatment success was defined as the absence of proven, probable, possible or suspected IFI through to 4 weeks after therapy. From April 2010 to December 2011, 155 patients were enrolled from 11 institutions in Korea, and 147 patients were analyzed. Of the 147 patients, 121 (82.3%) completed the protocol without premature interruption. Of the 132 patients in whom micafungin efficacy could be evaluated, treatment success was achieved in 119 patients (90.2%). There was no proven fungal infection in any patient. The number of patients with probable, possible and suspected IFI was two, two and nine, respectively. Thirty-five patients (23.8%) experienced 109 adverse events (AEs) possibly related to micafungin. No patients experienced grade IV AEs. Two patients (1.4%) discontinued micafungin administration due to adverse effects. None of the deaths were related to the study drug.