Sequential activation of different pathway networks in ischemia-affected and non-affected myocardium, inducing intrinsic remote conditioning to prevent left ventricular remodeling

We have analyzed the pathway networks of ischemia-affected and remote myocardial areas after repetitive ischemia/reperfusion (r-I/R) injury without ensuing myocardial infarction (MI) to elaborate a spatial- and chronologic model of cardioprotective gene networks to prevent left ventricular (LV) adverse remodeling. Domestic pigs underwent three cycles of 10/10 min r-I/R by percutaneous intracoronary balloon inflation/deflation in the mid left anterior descending artery, without consecutive MI. Sham interventions (n = 8) served as controls. Hearts were explanted at 5 h (n = 6) and 24 h (n = 6), and transcriptomic profiling of the distal (ischemia-affected) and proximal (non-affected) anterior myocardial regions were analyzed by next generation sequencing (NGS) and post-processing with signaling pathway impact and pathway network analyses. In ischemic region, r-I/R induced early activation of Ca-, adipocytokine and insulin signaling pathways with key regulator STAT3, which was also upregulated in the remote areas together with clusterin (CLU) and TNF-alpha. During the late phase of cardioprotection, antigen immunomodulatory pathways were activated with upregulation of STAT1 and CASP3 and downregulation of neprilysin in both zones, suggesting r-I/R induced intrinsic remote conditioning. The temporo-spatially differently activated pathways revealed a global myocardial response, and neprilysin and the STAT family as key regulators of intrinsic remote conditioning for prevention of adverse remodeling.

RNAi-Mediated Knockdown of Protein Expression

RNA interference is an essential method for studying genomic functions of single genes by loss-of-function experiments. Short interfering siRNAs are efficiently transfected into cultured cells to enable RISC-mediated mRNA cleavage and inhibition of translation in a sequence-specific manner. RNAi enables knockdown of single genes and screening for specific cellular processes or outcomes. In this chapter, we describe a detailed universal protocol for lipoplex-mediated siRNA transfection for cell cultures and cell lysis for subsequent RNA or protein analysis. The experimental procedure is described for verification of knockdown and includes cell lysis for mRNA or protein quantification. Important aspects for specific gene silencing and potential pitfalls are discussed.

Inhibition of CD34+ cell migration by matrix metalloproteinase-2 during acute myocardial ischemia, counteracted by ischemic preconditioning

Background. Mobilization of bone marrow-origin CD34+ cells was investigated 3 days (3d) after acute myocardial infarction (AMI) with/without ischemic preconditioning (IP) in relation to stromal-derived factor-1 (SDF-1α)/ chemokine receptor type 4 (CXCR4) axis, to search for possible mechanisms behind insufficient cardiac repair in the first days post-AMI.  Methods. Closed-chest reperfused AMI was performed by percutaneous balloon occlusion of the mid-left anterior descending (LAD) coronary artery for 90min, followed by reperfusion in pigs. Animals were randomized to receive either IP initiated by 3x5min cycles of re-occlusion/re-flow prior to AMI (n=6) or control AMI (n=12). Blood samples were collected at baseline, 3d post-AMI, and at 1-month follow-up to analyse chemokines and mobilized CD34+ cells. To investigate the effect of acute hypoxia, SDF-1α and matrix metalloproteinase (MMP)-2 in vitro were assessed, and a migration assay of CD34+ cells toward cardiomyocytes was performed.  Results. Reperfused AMI induced significant mobilisation of CD34+ cells (baseline: 260±75 vs. 3d: 668±180; P<0.001) and secretion of MMP-2 (baseline: 291.83±53.40 vs. 3d: 369.64±72.89; P=0.011) into plasma, without affecting the SDF-1α concentration. IP led to the inhibition of MMP-2 (IP: 165.67±47.99 vs. AMI: 369.64±72.89; P=0.004) 3d post-AMI, accompanied by increased release of SDF-1α (baseline: 23.80±12.36 vs. 3d: 45.29±11.31; P=0.05) and CXCR4 (baseline: 0.59±0.16 vs. 3d: 2.06±1.42; P=0.034), with a parallel higher level of mobilisation of CD34+ cells (IP: 881±126 vs. AMI: 668±180; P=0.026), compared to non-conditioned AMI. In vitro, CD34+ cell migration toward cardiomyocytes was enhanced by SDF-1α, which was completely abolished by 90min hypoxia and co-incubation with MMP-2.  Conclusions. Non-conditioned AMI induces MMP-2 release, hampering the ischemia-induced increase in SDF-1α and CXCR4 by cleaving the SDF-1α/CXCR4 axis, with diminished mobilization of the angiogenic CD34+ cells. IP might influence CD34+ cell mobilization via inhibition of MMP-2.

Molecular Imaging of Angiogenesis in Cardiac Regeneration

PURPOSE OF REVIEW

Myocardial infarction (MI) leading to heart failure displays an important cause of death worldwide. Adequate restoration of blood flow to prevent this transition is a crucial factor to improve long-term morbidity and mortality. Novel regenerative therapies have been thoroughly investigated within the past decades.

RECENT FINDINGS

Increased angiogenesis in infarcted myocardium has shown beneficial effects on the prognosis of MI; therefore, the proangiogenic capacity of currently tested treatments is of specific interest. Molecular imaging to visualize formation of new blood vessels in vivo displays a promising option to monitor proangiogenic effects of regenerative substances.

SUMMARY

Based on encouraging results in preclinical models, molecular angiogenesis imaging has recently been applied in a small set of patients. This article reviews recent literature on noninvasive in vivo molecular imaging of angiogenesis after MI as an integral part of cardiac regeneration.

[Cellular replacement strategies and adult neurogenesis in idiopathic Parkinson's disease]

Parkinson's disease (PD) is the most common age-related movement disorder and characterized by slowly progressive neurodegeneration resulting in motor symptoms, such as bradykinesia, rigidity, tremor and postural instability. Moreover, non-motor symptoms, such as hyposmia, anxiety and depression reduce the quality of life in PD. Motor symptoms are associated with a distinct striatal dopaminergic deficit resulting from axonal dysfunction and neuronal loss in the substantia nigra (SN). Recent progress in stem cell technology allows the optimization of cellular transplantation strategies in order to alleviate the motor deficit, which potentially leads to a reactivation of this therapeutic strategy. Besides neurodegenerative processes impaired adult neurogenesis and consequentially reduced endogenous cellular plasticity may play an important role in PD. This article discusses the notion that non-motor symptoms in PD may partly be explained by reduced adult neurogenesis in the olfactory bulb and hippocampus.

[Vascular parkinsonism]

Parkinsonism may result from cerebral vascular disorders that feature white matter lesions and small vessel pathology. Vascular Parkinsonism typically presents as lower body Parkinsonism with predominant gait impairment. Urinary incontinence and cognitive decline are additional features of the disease. There is a considerable overlap between vascular Parkinsonism and vascular dementia. We review the clinical characteristics of vascular Parkinsonism and discuss the current treatment approaches, as well as the role of brain imaging for the diagnostic workup. .

Population pharmacokinetic modeling and simulations of dopamine Dd2 receptor occupancy of long-acting intramuscular risperidone-ISM

Introduction

Risperidone-ISM is a new long-acting intramuscular formulation intended to achieve sustained plasma concentrations over 4 weeks without oral supplementation. The clinical efficacy to risperidone has been associated with 65–80% occupancy of dopamine D2 receptor (D2RO) and a mean Cmax between 7.5 ng/mL and 80 ng/mL.

Aim

Use a population PK/PD model to predict the PK and the D2RO for Risperidone-ISM in schizophrenic patients and to characterize the relationship among doses, in order to guide dose selection for a future Phase-III trial.

Methods

A population PK/PD analysis for Risperidone-ISM using Monolix software was conducted based on 6641 plasma samples from two Phase-I studies (17 healthy subjects and 31 schizophrenic subjects, respectively) and 1 Phase-II study (60 schizophrenic subjects). Simulations were subsequently undertaken predicting the steady state PK and D2RO after multiple Risperidone-ISM doses administered every 28 days for 12 weeks.

Results

Doses of 75 and 100 mg, administered either in gluteal or deltoid muscle, were predicted to result in median Cmax and Ctrough that stayed between 7.5 ng/mL and 80 ng/mL. At steady state 75 mg and 100 mg dose (gluteal) achieved a D2RO average [min–max] of 70.8% [61.4–80.4] and 74.3% [66.2–82.1], respectively; a 75-mg and 100-mg dose (deltoid) achieved a D2RO average [min–max] of 69.3% [56.5–80.3] and 73.0% [61.8–82.1], respectively. The model estimated that the 65% D2RO occurs within first 8 h after treatment.

Conclusions

Simulations were carried out supporting doses of 75 mg and 100 mg Risperidone-ISM to show the greatest efficacy and safety potential to be assessed in the future Phase-III trial.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

[Management and Outcome of Surgery in Patients with Severe Pulmonary Hypertension--A Single-Center Experience]

BACKGROUND

Patients with pulmonary hypertension (PH) are at high risk when undergoing surgery. Up to one-third of patients suffer complications; recent studies report a mortality rate of 1 to 7%. Frequent events are deterioration of right heart function and infectious or bleeding complications.

METHODS

Data of patients (age ≥ 18) with precapillary PH who need to undergo elective surgery between January 2006 and March 2015 were included in this retrospective analysis. All patients who were planned for surgery underwent the same procedure. First, patients were evaluated in the PH center. Thereafter, PH-relevant data were discussed with the surgeon/anesthesiologist team for risk-adapted planning of anesthesia and intervention. The present analysis comprises patient characteristics and information about surgery and post-interventional course.

RESULTS

This study analyzes 31 surgical procedures carried out in PH patients (male: n = 8; PH-group I: n = 23, group III: n = 3, group IV: n = 5, mean age: 59.5 ± 15.3 years). Patients were characterized by compromised hemodynamics and exercise capacity: pulmonary vascular resistance: 805.4 ± 328.5 dyn*s*cm(-5), mean pulmonary arterial pressure: 46.3 ± 9.3 mmHg, 6-minute walking distance: 350.3 ± 123.3 m.The majority of interventions were performed under general anesthesia (n = 24). In 25 cases, the intraoperative monitoring was complemented with right heart catheterization.Eight interventions were associated with complications, three of which were serious. One patient died postoperatively owing to sepsis and right heart failure.

CONCLUSION

A careful and structured planning of surgical interventions in patients with PH and the choice of surgical procedure and anesthesia adapted to the conditions of PH might help avoid complications. Further multicentric studies are needed.

Triterpenoic Acids from Apple Pomace Enhance the Activity of the Endothelial Nitric Oxide Synthase (eNOS)

Pomace is an easy-accessible raw material for the isolation of fruit-derived compounds. Fruit consumption is associated with health-promoting effects, such as the prevention of cardiovascular disease. Increased vascular nitric oxide (NO) bioavailability, for example, due to an enhanced endothelial nitric oxide synthase (eNOS) activity, could be one molecular mechanism mediating this effect. To identify compounds from apple (Malus domestica Borkh.) pomace that have the potential to amplify NO bioavailability via eNOS activation, a bioassay-guided fractionation of the methanol/water (70:30) extract has been performed using the (14)C-L-arginine to (14)C-L-citrulline conversion assay (ACCA) in the human endothelium-derived cell line EA.hy926. Phytochemical characterization of the active fractions was performed using the spectrophotometric assessment of the total phenolic content, as well as TLC, HPLC-DAD-ELSD, and HPLC-MS analyses. Eleven triterpenoic acids, of which one is a newly discovered compound, were identified as the main constituents in the most active fraction, accompanied by only minor contents of phenolic compounds. When tested individually, none of the tested compounds exhibited significant eNOS activation. Nevertheless, cell stimulation with the reconstituted compound mixture restored eNOS activation, validating the potential of apple pomace as a source of bioactive components.

From sweet to sweat: Hedonic olfactory range is impaired in Parkinson's disease

INTRODUCTION

Olfactory dysfunction and neuropsychological symptoms like depression and anhedonia are common non-motor symptoms in Parkinson's disease (PD). The assessment of both functional domains includes clinical examination, olfactory testing, and standardized questionnaires. While olfaction is readily assessed by functional tests, the distinction of anhedonia as a separate symptom from other depressive symptoms is challenging. Thus, a test focusing on the assessment of hedonic olfaction may be helpful in the assessment of neuropsychological symptoms in PD.

METHODS

We examined anhedonia by evaluating the perception of pleasantness of odors in PD patients (n = 57) and healthy controls (n = 46). Pleasantness of odors was registered on a visual 9-point scale. For the assessment of anhedonia we used the Snaith-Hamilton-Pleasure-Scale (SHAPS). Depression was evaluated with the Zung Self-Rating Depression Scale and the Beck Depression Inventory II.

RESULTS

PD patients showed a substantial reduction in hedonic olfaction compared to controls (hedonic score: 1.5 vs. 2.2). Hyposmia, one of the most prevalent non-motor symptoms in PD, was a confounding factor. However, even normosmic PD patients showed a reduced hedonic olfaction compared to controls (hedonic score: 1.6 vs. 2.2). Furthermore, we observed a correlation between hedonic olfaction and the SHAPS-score for PD patients even though positive SHAPS-rating was observed in 9% of PD patients only, while no correlation to depression was present.

CONCLUSION

These findings suggest that reduced hedonic olfaction might be an additional neuropsychological feature, probably giving insights into changes in hedonic tone complementary to hyposmia and depression in PD.

[Cardiopulmonary exercise testing in chronic obstructive pulmonary disease (COPD) - breath-functional characterization and disease severity assessment]

COPD is a heterogeneous disease with a wide range of clinical phenotypes and breath-functional dysfunctions. Cardiopulmonary exercise testing (CPET) allows describing all component parts of breathing and determining exercise capacity and the mechanisms of exercise limitation. From these aspects 64 COPD patient stages II, III and IV according to the conventional GOLD classification were examined by means of CPET to evaluate whether CPET can provide a better functional characterization of COPD than the standard investigation procedures in pulmonary practice.We could show that in pulmonary practice CPET is safely and effectively practicable in stable COPD patients of all GOLD stages. This method allowed a clinical and prognostic disease severity assessment of all patients, proving important differences of peak oxygen uptake in each GOLD stage, so that patients in spite of identical GOLD disease severity were to be assigned to different prognostic groups according CPET criteria. Furthermore, we found relevant differences of individual breath-functional patterns in exercise, which can neither be objectified nor be prognosticated by standard investigation procedures at rest.Therefore CPET allows, aside from an objective clinical and prognostic disease severity assessment, also a breath-functional evaluation in a subtly way in COPD patients reflecting the multidimensional background of the disease with variable dysfunctions in pulmonary ventilation, gas exchange, circulation and muscular function as well as associated cardio vascular comorbidities. The breath-functional phenotyping of the COPD patient seems to be meaningful in particular for an individualised therapy management.

[Dyspnoea in Patients with Pulmonary Hypertension (PH) - a Survey in Spezialized German PH Centres]

Dyspnoea is the predominant symptom in patients with pulmonary hypertension (PH) at diagnosis. However, since dyspnoea is nonspecific and often occurs in a number of common diseases, the presence of PH can easily be underdiagnosed.In addition, this symptom underlies a high variability in the subjective perception, therefore further diagnostic procedures are often delayed by the patients.A survey of the incidence and severity of dyspnoea in 372 patients with PAH was conducted by questionnaire in German centres. Age, sex distribution and the range of comorbidities corresponded to the findings of national and international registries.Approximately 99 % of patients reported the presence of dyspnoea on exertion, even at low loads.Remarkably, in 13 % of patients dyspnoea occurs as a paroxysmal symptom, which may lead to the differential diagnosis of bronchial asthma. In addition, the patients who were being followed in specialized PH centres reported an increase in dyspnoea during the last year.The results of the survey on the incidence of dyspnoea in patients with PAH are consistent with the findings of international studies.

Post-hoc comparison of vitamin D status at three timepoints during pregnancy demonstrates lower risk of preterm birth with higher vitamin D closer to delivery

There have been observational reports that maternal vitamin D status at baseline and not closest to delivery is a better predictor of pregnancy outcomes, suggesting that a cascade of events is set into motion that is not modifiable by vitamin D supplementation during later pregnancy. To address this issue, in this exploratory post-hoc analysis using correlation and logistic regression, we sought to measure the strength of the association between serum 25(OH)D concentrations at 3 timepoints during pregnancy: baseline, 1st trimester (<16 weeks); 2nd trimester (16-26 weeks); and 3rd trimester (≥27 weeks) and preterm birth. It was hypothesized that the 25(OH)D value closest to delivery would be most significantly associated with preterm birth. To accomplish this objective, the datasets from NICHD (n=333) and Thrasher Research Fund (n=154) vitamin D supplementation pregnancy studies were combined. The results of this analysis were that 25(OH)D values closer to delivery were more strongly correlated with gestational age at delivery than earlier values: 1st trimester: r=0.11 (p=0.02); 2nd trimester: r=0.08 (p=0.09); and 3rd trimester: r=0.15 (p=0.001). When logistic regression was performed with preterm birth (<37 weeks) as the outcome and 25(OH)D quartiles as the predictor variable, adjusting for study and participant race/ethnicity, as with the correlation analysis, the measurements closer to delivery were more significantly associated and had a higher magnitude of effect. That is, at baseline, those who had serum concentrations <50nmol/L (20ng/mL) had 3.3 times of odds of a preterm birth compared to those with serum concentrations ≥100nmol/L (40ng/mL; p=0.27). At 2nd trimester, the odds were 2.0 fold (p=0.21) and at the end of pregnancy, the odds were 3.8 fold (p=0.01). The major findings from this exploratory analysis were: (1) maternal vitamin D status closest to delivery date was more significantly associated with preterm birth, suggesting that later intervention as a rescue treatment may positively impact the risk of preterm delivery, and (2) a serum concentration of 100nmol/L (40ng/mL) in the 3rd trimester was associated with a 47% reduction in preterm births. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.

Going beyond the liver: progress and challenges of targeted delivery of siRNA therapeutics

Therapeutic gene silencing promises significant progress in pharmacotherapy, including considerable expansion of the druggable target space and the possibility for treating orphan diseases. Technological hurdles have complicated the efficient use of therapeutic oligonucleotides, and siRNA agents suffer particularly from insufficient pharmacokinetic properties and poor cellular uptake. Intense development and evolution of delivery systems have resulted in efficient uptake predominantly in liver tissue, in which practically all nanoparticulate and liposomal delivery systems show the highest accumulation. The most efficacious strategies include liposomes and bioconjugations with N-acetylgalactosamine. Both are in early clinical evaluation stages for treatment of liver-associated diseases. Approaches for achieving knockdown in other tissues and tumors have been proven to be more complicated. Selective targeting to tumors may be enabled through careful modulation of physical properties, such as particle size, or by taking advantage of specific targeting ligands. Significant barriers stand between sufficient accumulation in other organs, including endothelial barriers, cellular membranes, and the endosome. The brain, which is shielded by the blood-brain barrier, is of particular interest to facilitate efficient oligonucleotide therapy of neurological diseases. Transcytosis of the blood-brain barrier through receptor-specific docking is investigated to increase accumulation in the central nervous system. In this review, the current clinical status of siRNA therapeutics is summarized, as well as innovative and promising preclinical concepts employing tissue- and tumor-targeted ligands. The requirements and the respective advantages and drawbacks of bioconjugates and ligand-decorated lipid or polymeric particles are discussed.