Co-administration of Nanowired Oxiracetam and Neprilysin with Monoclonal Antibodies to Amyloid Beta Peptide and p-Tau Thwarted Exacerbation of Brain Pathology in Concussive Head Injury at Hot Environment.

Environmental temperature adversely affects the outcome of concussive head injury (CHI)-induced brain pathology. Studies from our laboratory showed that animals reared at either cold environment or at hot environment exacerbate brain pathology following CHI. Our previous experiments showed that nanowired delivery of oxiracetam significantly attenuated CHI-induced brain pathology and associated neurovascular changes. Military personnel are the most susceptible to CHI caused by explosion, blasts, missile or blunt head trauma leading to lifetime functional and cognitive impairments affecting the quality of life. Severe CHI leads to instant death and/or lifetime paralysis. Military personnel engaged in combat operations are often subjected to extreme high or low environmental temperature zones across the globe. Thus, further exploration of novel therapeutic agents at cold or hot ambient temperatures following CHI are the need of the hour. CHI is also a major risk factor for developing Alzheimer's disease by enhancing amyloid beta peptide deposits in the brain. In this review, effect of hot environment on CHI-induced brain pathology is discussed. In addition, whether nanodelivery of oxiracetam together with neprilysin and monoclonal antibodies (mAb) to amyloid beta peptide and p-tau could lead to superior neuroprotection in CHI is explored. Our results show that co-administration of oxiracetam with neprilysin and mAb to AßP and p-tau significantly induced superior neuroprotection following CHI in hot environment, not reported earlier.

Genetically engineered exosomes display RVG peptide and selectively enrich a neprilysin variant: a potential formulation for the treatment of Alzheimer's disease.

Exosome is a promising next generation nano-based drug delivery vehicle. However, the unknown molecular mechanisms underlying its natural tissue tropism and the relatively low quantity of naturally enriched molecules of therapeutic value hamper exosome's clinical application. The aim of the research was to create a targeted and highly efficacious exosome formulation for the treatment of Alzheimer's disease (AD). Genetic engineering techniques combined with co-transfection of parental cells were employed to create an exosome formulation that displays RVG peptide on its surface targeting α7-nAChR and simultaneously enriches a neprilysin variant with increased specificity and efficacy in degrading ß amyloid peptide (Aß). The exosome formulation was preferentially internalised into cell lines in an α7-nAChR expression level-dependent manner. When incubated with Aß-producing N2a cells, it significantly decreased intracellular and secreted Aß40 levels, a potency that is superior to exosomes derived from adipose-derived stem cell. When systemically administered into mice, the exosome formulation was preferentially targeted to the hippocampus region of the brain and significantly decreased the expression of proinflammatory genes, IL1α, TNFα and NF-κB, and simultaneously increased the expression of anti-inflammatory gene, IL10. Our exosome formulation may be explored as an over-the-counter treatment for AD.

Incidence and Outcomes of Pneumonia in Patients With Heart Failure.

BACKGROUND: The incidence of pneumonia and subsequent outcomes has not been compared in patients with heart failure and reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). OBJECTIVES: This study aimed to examine the rate and impact of pneumonia in the PARADIGM-HF (Prospective Comparison of Angiotensin Receptor-Neprilysin Inhibitor With Angiotensin Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure) and PARAGON-HF (Prospective Comparison of ARNI with ARB Global Outcomes in Heart Failure with Preserved Ejection Fraction) trials. METHODS: The authors analyzed the incidence of investigator-reported pneumonia and the rates of HF hospitalization, cardiovascular death, and all-cause death before and after the occurrence of pneumonia, and estimated risk after the first occurrence of pneumonia in unadjusted and adjusted analyses (the latter including N-terminal pro-B-type natriuretic peptide). RESULTS: In PARADIGM-HF, 528 patients (6.3%) developed pneumonia after randomization, giving an incidence rate of 29 (95% CI: 27 to 32) per 1,000 patient-years. In PARAGON-HF, 510 patients (10.6%) developed pneumonia, giving an incidence rate of 39 (95% CI: 36 to 42) per 1,000 patient-years. The subsequent risk of all trial outcomes was elevated after the occurrence of pneumonia. In PARADIGM-HF, the adjusted hazard ratio (HR) for the risk of death from any cause was 4.34 (95% CI: 3.73 to 5.05). The corresponding adjusted HR in PARAGON-HF was 3.76 (95% CI: 3.09 to 4.58). CONCLUSIONS: The incidence of pneumonia was high in patients with HF, especially HFpEF, at around 3 times the expected rate. A first episode of pneumonia was associated with 4-fold higher mortality. (Prospective Comparison of Angiotensin Receptor-Neprilysin Inhibitor With Angiotensin-Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure [PARADIGM-HF], NCT01035255; Prospective Comparison of ARNI [Angiotensin Receptor-Neprilysin Inhibitor] With ARB [Angiotensin Receptor Blocker] Global Outcomes in Heart Failure With Preserved Ejection Fraction [PARAGON-HF], NCT01920711).

Nanowired delivery of cerebrolysin with neprilysin and p-Tau antibodies induces superior neuroprotection in Alzheimer's disease.

Alzheimer's disease (AD) is estimated to be afflicting over 55 millions of individual worldwide in 2018-19 for which no suitable clinical therapeutic measures have been developed so far. Thus, there is an urgent need to explore novel therapeutic strategies using nanodelivery of drugs and agents either alone or in combination for superior neuroprotection in AD and enhanced quality of life of the affected individuals. There are reports that AD is often associated with diminished neurotrophic factors and neprilysin together with enhancement of phosphorylated Tau (p-Tau) within the brain and in the cerebrospinal fluid (CSF). Thus, studies aiming to enhance neurotrophic factors and neprilysin together with neutralizing p-Tau within the central nervous system (CNS) may alleviate brain pathology in AD. In this review these strategies are discussed using nanotechnological approaches largely based on our own investigations in relation to current literature in the field.

Tratamiento farmacológico inicial del paciente con insuficiencia cardíaca con función sistólica reducida: ¿es importante el orden de inicio y las dosis conseguidas? / Initial pharmacological treatment of the patient with heart failure with reduced systolic function: is the order of the initial and subsequent doses important?

No disponible

Utility of natriuretic peptides to assess and manage patients with heart failure receiving angiotensin receptor blocker/neprilysin inhibitor therapy.

Levels of natriuretic peptides (NPs), such as B-type NP (BNP) and the N-terminal fragment of its prohormone (NT-proBNP), are well-established biomarkers for patients with heart failure (HF). Although these biomarkers have consistently demonstrated their value in the diagnosis and prognostication of HF, their ability to help clinicians in making treatment decisions remains debated. Moreover, some new HF drugs can affect concentrations of NPs, such as the prevention of BNP degradation by angiotensin receptor/neprilysin inhibitors (ARNIs), and may present a challenge in the interpretation of levels of BNP. Use of NT-proBNP measurement has been suggested in the context of ARNI therapy because its concentrations are not affected by neprilysin inhibition. As biomarkers are reconsidered in the context of ARNI therapy, cutoff levels and the effects of individual patient characteristics, such as renal function and age, on biomarker concentrations should be reassessed.

Combined neprilysin and renin-angiotensin system inhibition in heart failure with reduced ejection fraction: a meta-analysis.

AIMS: The combined neprilysin/renin-angiotensin system (RAS) inhibitor sacubitril/valsartan reduced cardiovascular death or heart failure hospitalization, cardiovascular death, and all-cause mortality in a large outcomes trial. While sacubitril/valsartan is the only currently available drug in its class, there are two prior clinical trials in heart failure with omapatrilat, another combined neprilysin/RAS inhibitor. Using all available evidence can inform clinicians and policy-makers. METHODS AND RESULTS: We performed a meta-analysis using data from three trials in heart failure with reduced EF that compared combined neprilysin/RAS inhibition with RAS inhibition alone and reported clinical outcomes: IMPRESS (n = 573), OVERTURE (n = 5770), and PARADIGM-HF (n = 8399). We assessed the pooled hazard ratio (HR) for all-cause death or heart failure hospitalization, and for all-cause mortality in random-effects models, comparing combined neprilysin/RAS inhibition with ACE inhibition alone. The composite outcome of death or heart failure hospitalization was reduced numerically in patients receiving combined neprilysin/RAS inhibition in all three trials, with a pooled HR of 0.86, 95% confidence interval (CI) 0.76-0.97, P = 0.013. For the endpoint of all-cause mortality, the pooled HR was 0.88, 95% CI 0.80-0.98, P = 0.021. Combined neprilysin/RAS inhibition compared with ACE inhibition was associated with more hypotension, but less renal dysfunction and hyperkalaemia in all three trials. CONCLUSIONS: Pooled estimates from three trials with two separate drugs of combined neprilysin/RAS inhibition support the use of combined neprilysin/RAS inhibition in heart failure with reduced EF.

Neprilysin Inhibits Coagulation through Proteolytic Inactivation of Fibrinogen.

Neprilysin (NEP) is an endogenous protease that degrades a wide range of peptides including amyloid beta (Aß), the main pathological component of Alzheimer's disease (AD). We have engineered NEP as a potential therapeutic for AD but found in pre-clinical safety testing that this variant increased prothrombin time (PT) and activated partial thromboplastin time (APTT). The objective of the current study was to investigate the effect of wild type NEP and the engineered variant on coagulation and define the mechanism by which this effect is mediated. PT and APTT were measured in cynomolgus monkeys and rats dosed with a human serum albumin fusion with an engineered variant of NEP (HSA-NEPv) as well as in control plasma spiked with wild type or variant enzyme. The coagulation factor targeted by NEP was determined using in vitro prothrombinase, calibrated automated thrombogram (CAT) and fibrin formation assays as well as N-terminal sequencing of fibrinogen treated with the enzyme. We demonstrate that HSA-NEP wild type and HSA-NEPv unexpectedly impaired coagulation, increasing PT and APTT in plasma samples and abolishing fibrin formation from fibrinogen. This effect was mediated through cleavage of the N-termini of the Aα- and Bß-chains of fibrinogen thereby significantly impairing initiation of fibrin formation by thrombin. Fibrinogen has therefore been identified for the first time as a substrate for NEP wild type suggesting that the enzyme may have a role in regulating fibrin formation. Reductions in NEP levels observed in AD and cerebral amyloid angiopathy may contribute to neurovascular degeneration observed in these conditions.

Genetic Factors Influencing B-type Natriuretic Peptide-Mediated Production of Cyclic Guanosine Monophosphate and Blood Pressure Effects in Heart Failure Patients.

Natriuretic peptides (NPs) represent a critical pathway in heart failure (HF). We explored genetic determinants of pharmacodynamic effects of B-type NP (BNP) and changes in plasma cyclic guanosine monophosphate (cGMP) and blood pressure (BP). HF patients (n = 135) received recombinant human BNP (nesiritide) at standard doses, and plasma cGMP levels were measured at baseline and during infusion. We tested the association of 119 single nucleotide polymorphisms (SNPs) in 4 candidate genes (NPR1, NPR2, NPR3, and membrane metallo-endopeptidase (MME)) with the change in cGMP and BP. Gene-based testing for association of genetic variation with endpoints was significant only for MME. Upon individual SNP testing, two loci in MME were associated with ΔcGMP; another (rs16824656) showed association with BP change. In summary, the pharmacodynamic effects of BNP vary substantially in HF patients and are associated with genetic variation in MME. MME genetic variation may be an important determinant of NP-mediated effects in humans.

Drug therapy for patients with systolic heart failure after the PARADIGM-HF trial: in need of a new paradigm of LCZ696 implementation in clinical practice.

Heart failure represents a primary cause of morbidity and mortality in older people and despite significant therapeutic advances, it is still characterized by important unmet needs, thus remaining a challenging field of clinical research. The recent PARADIGM-HF trial compared the novel compound LCZ696, a combination of the angiotensin receptor blocker valsartan and the neprilysin inhibitor sacubitril, versus the angiotensin-converting enzyme inhibitor enalapril in 8,442 patients with symptomatic chronic systolic heart failure. LCZ696 led to a 20% reduction in the rate of death or hospitalization for heart failure and a 16% reduction in the rate of all-cause death compared to enalapril at 3.5 years of follow-up. Despite those impressive results, the clinical application of this novel agent that requires the substitution of a cornerstone of current heart failure therapy, the angiotensin-converting enzyme inhibitors, should follow careful steps as imposed by the study design, the recruited population and the outcome in specific patient subgroups. Further insights into the effects of LCZ696 will be provided by the ongoing PARAGON-HF trial in patients with diastolic heart failure.

Sustained peripheral depletion of amyloid-ß with a novel form of neprilysin does not affect central levels of amyloid-ß.

Alzheimer's disease is characterized by the accumulation of amyloid deposits in the brain and the progressive loss of cognitive functions. Although the precise role of amyloid-ß in disease progression remains somewhat controversial, many efforts to halt or reverse disease progression have focussed on reducing its synthesis or enhancing its removal. It is believed that brain and peripheral soluble amyloid-ß are in equilibrium and it has previously been hypothesized that a reduction in peripheral amyloid-ß can lower brain amyloid-ß, thereby reducing formation of plaques predominantly composed of insoluble amyloid-ß; the so-called peripheral sink hypothesis. Here we describe the use of an amyloid-ß degrading enzyme, the endogenous metallopeptidase neprilysin, which is fused to albumin to extend plasma half-life and has been engineered to confer increased amyloid-ß degradation activity. We used this molecule to investigate the effect of degradation of peripheral amyloid-ß on amyloid-ß levels in the brain and cerebrospinal fluid after repeated intravenous dosing for up to 4 months in Tg2576 transgenic mice, and 1 month in rats and monkeys. This molecule proved highly effective at degradation of amyloid-ß in the periphery but did not alter brain or cerebrospinal fluid amyloid-ß levels, suggesting that the peripheral sink hypothesis is not valid and is the first time that this has been demonstrated in non-human primates.

Convection-enhanced delivery of neprilysin: a novel amyloid-ß-degrading therapeutic strategy.

Enzymatic degradation contributes to the control of intracerebral amyloid-ß (Aß) peptide levels. Previous studies have demonstrated the therapeutic potential of viral vector-mediated neprilysin (NEP) gene therapy in mouse models of Alzheimer's disease (AD). However, clinical translation of NEP gene therapy is limited by ethical and practical considerations. In this study we have assessed the potential of convection-enhanced delivery (CED) as a means of elevating intracerebral NEP level and activity and degrading endogenous Aß. We analyzed the interstitial and perivascular distribution of NEP following CED into rat striatum. We measured NEP protein level, clearance, activity, and toxicity by ELISA for NEP and synaptophysin, NEP-specific activity assay, and immunohistochemistry for NEP, NeuN, glial fibrillary acidic protein and Iba1. We subsequently performed CED of NEP in normal aged rats and measured endogenous Aß by ELISA. CED resulted in widespread distribution of NEP, and a 20-fold elevation of NEP protein level with preservation of enzyme activity and without evidence of toxicity. CED in normal, aged rats resulted in a significant reduction in endogenous Aß(40) (p = 0.04), despite rapid NEP clearance from the brain (half-life ~3 h). CED of NEP has therapeutic potential as a dynamically controllable Aß(40)-degrading therapeutic strategy for AD. Further studies are required to determine the longer term effects on Aß (including Aß(42)) and on cognitive function.

Peripheral delivery of a CNS targeted, metalo-protease reduces aß toxicity in a mouse model of Alzheimer's disease.

Alzheimer's disease (AD), an incurable, progressive neurodegenerative disorder, is the most common form of dementia. Therapeutic options have been elusive due to the inability to deliver proteins across the blood-brain barrier (BBB). In order to improve the therapeutic potential for AD, we utilized a promising new approach for delivery of proteins across the BBB. We generated a lentivirus vector expressing the amyloid ß-degrading enzyme, neprilysin, fused to the ApoB transport domain and delivered this by intra-peritoneal injection to amyloid protein precursor (APP) transgenic model of AD. Treated mice had reduced levels of Aß, reduced plaques and increased synaptic density in the CNS. Furthermore, mice treated with the neprilysin targeting the CNS had a reversal of memory deficits. Thus, the addition of the ApoB transport domain to the secreted neprilysin generated a non-invasive therapeutic approach that may be a potential treatment in patients with AD.

Efficient processing of Alzheimer's disease amyloid-Beta peptides by neuroectodermally converted mesenchymal stem cells.

Most disease-modifying therapeutic approaches in Alzheimer's disease (AD) aim to reduce the accumulation of neurotoxic amyloid-beta (Abeta) peptides as a hallmark of AD pathogenesis. Here we report the in vitro basis for a potential autologous stem cell-based strategy for widespread delivery of enzymatic activities against Abeta formation in the brain. We detected the functional induction of two genes upon neuroectodermal conversion of human adult mesenchymal stem cells (MSCs), namely F-spondin and neprilysin (CD10), with a 4,992 + or - 697-fold and 692 + or - 226-fold increase of mRNA levels in converted cells compared to MSCs, respectively (n = 3; P < 0.01). These genes are known to be involved in the formation and degradation of Abeta peptides, respectively. Consistently, coincubation of the neuroectodermally converted MSCs with HEK-293 cells stably expressing amyloid precursor protein (APP) lead to a significant cell dose-dependent decrease of Abeta peptides. These in vitro results indicate that MSCs might be useful vehicles for delivering anti-Abeta activity depicting a causal stem cell-based therapeutic approach to treat AD.

Activation of the amyloid cascade in apolipoprotein E4 transgenic mice induces lysosomal activation and neurodegeneration resulting in marked cognitive deficits.

The allele E4 of apolipoprotein E (apoE4), the most prevalent genetic risk factor for Alzheimer's disease, is associated histopathologically with elevated levels of brain amyloid. This led to the suggestion that the pathological effects of apoE4 are mediated by cross-talk interactions with amyloid beta peptide (Abeta), which accentuate the pathological effects of the amyloid cascade. The mechanisms underlying the Abeta-mediated pathological effects of apoE4 are unknown. We have shown recently that inhibition of the Abeta-degrading enzyme neprilysin in brains of wild-type apoE3 and apoE4 mice results in rapid and similar elevations in their total brain Abeta levels. However, the nucleation and aggregation of Abeta in these mice were markedly affected by the apoE genotype and were specifically enhanced in the apoE4 mice. We presently used the neprilysin inhibition paradigm to analyze the neuropathological and cognitive effects that are induced by apoE4 after activation of the amyloid cascade. This revealed that apoE4 stimulates isoform specifically the degeneration of hippocampal CA1 neurons and of entorhinal and septal neurons, which is accompanied by the accumulation of intracellular Abeta and apoE and with lysosomal activation. Furthermore, these neuropathological effects are associated isoform specifically with the occurrence of pronounced cognitive deficits in the ApoE4 mice. These findings provide the first in vivo evidence regarding the cellular mechanisms underlying the pathological cross talk between apoE4 and Abeta, as well as a novel model system of neurodegeneration in vivo that is uniquely suitable for studying the early stages of the amyloid cascade and the effects thereon of apoE4.

Novel strategies for Alzheimer's disease treatment.

Considerable progress has been made in recent years towards better understanding the pathogenesis of Alzheimer's disease (AD), a dementing neurodegenerative disorder that affects > 10 million individuals in the US and Europe combined. Recent studies suggest that alterations in the processing of amyloid precursor protein (APP), resulting in the accumulation of amyloid-beta protein (Abeta) and the formation of oligomers leads to synaptic damage and neurodegeneration. Therefore, strategies for treatment development have been focused on reducing Abeta accumulation using, among other approaches, antiaggregation molecules, regulators of the APP proteolysis and processing, reducing APP production (e.g., small-interfering RNA), and increasing Abeta clearance with antibodies, apolipoprotein E and Abeta-degrading enzymes (e.g., neprilysin). The main focus of this review is on novel treatments for AD with a special emphasis on delivering neuroprotective and antiamyloidogenic molecules by gene therapy and by promoting neurogenesis.

The hemodynamic and metabolic profiles of Zucker diabetic fatty rats treated with a single molecule triple vasopeptidase inhibitor, CGS 35601.

CGS 35601 is a triple vasopeptidase inhibitor (VPI) of angiotensin converting enzyme (ACE), neutral endopeptidase (NEP), and endothelin (ET) converting enzyme-1 (ECE-1), with respective IC(50) values of 22, 2, and 55 nM. The aim of the present study was to establish the hemodynamic profile of Zucker diabetic fatty (Zdf)-Fatty rats, a high-fat diet gene-prone model developing spontaneous Type 2 diabetes (T2D) and the effects of CGS 35601. Male Zdf-Fatty (14 weeks, n = 17-23), Zdf-Lean (14 weeks, n = 8-10), and Wistar (14 weeks, n = 9-10) rats on distinct diets were implanted with a catheter in the left carotid and placed individually in a metabolic cage for 30 days. The hemodynamic profile and some metabolic biomarkers were assessed daily. After a 7-day stabilization period, the Zdf-Fatty rats were divided into two groups: Group 1, controls (n = 7-10) receiving vehicle-saline (250 microl/hr) and Group 2, (n = 10-13) receiving increasing doses of CGS 35601 (0.1, 1, and 5 mg/kg/day x 6 days each, intra-arterially) followed by a 5-day washout period. Mean arterial blood pressure (MABP) of young Zdf-Fatty rats was compared with age-matched Zdf-Lean and Wistar rats, which were found similar. MABP decreased by 5.9% (from baseline at 102 +/- 5 to 96 +/- 4 mmHg), 12.7% (to 89 +/- 6 mmHg) and 21.6% (to 80 +/- 4 mmHg), at 0.1, 1, and 5 mg/kg/day, respectively, in CGS 35601-treated Zdf-Fatty rats. Systolic and diastolic blood pressures were similarly reduced. The heart rate was not affected. Hyperglycemic status and insulin-resistance were not modulated by short-term treatment. CGS 35601 presented an excellent short-term safety profile. This novel molecule and class of VPI may be of interest for lowering vascular tone. Further long-term studies, once cardiovascular and renal complications have developed in this T2D rat model are warranted to define the efficacy of this class of VPI.

Triple VPI CGS 35601 reduces high blood pressure in low-renin, high-salt Dahl salt-sensitive rats.

We previously reported that CGS 35601, a potent triple inhibitor of angiotensin-converting enzyme, neutral endopeptidase, and endothelin-converting enzyme 1, completely normalized mean arterial blood pressure (MABP) in 36-week-old spontaneously hypertensive rats, a normal renin model. The aim of the present study was to determine the effects of this triple vasopeptidase inhibitor (VPI) on the hemodynamic profile of instrumented, conscious, and unrestrained Dahl salt-sensitive (DSS) rats, a gene-prone, high-salt diet-induced low-renin hypertension model. Male DSS rats (mean weight [+/-SEM], 385 +/- 10 g) were fed a normal diet (Group 1) or a high-salt diet (Groups 2 and 3; 8% NaCl in food) for 6 weeks and then instrumented with a carotid catheter and placed individually in metabolic cages for 30 days. The hemodynamic, hematological, and biochemical profiles were assessed daily. Dose-dependent treatment started after a 7-day stabilization period in Groups 1 and 2 (vehicle dosage, 250 microl/hr) and Group 3 (CGS 35601 dosages of 0.1, 1, and 5 mg/kg/day for 6 days per dose by means of constant intra-arterial infusion), followed by a 5-day washout period. Two additional groups included normotensive Wistar rats (Group 4) and DSS rats that received a double high-salt solid (8% NaCl) and liquid (1% NaCl) diet (Group 5). The MABP in rats receiving CGS 35601 decreased in a dose-dependent fashion toward the baseline level observed in DSS rats receiving a normal diet. The heart rate was unaffected. The hemodynamic profile returned to normal during the washout period. This novel triple VPI is a potent and effective antihypertensive agent with a safe short-term profile that may be of interest for treating hypertension and other cardiovascular diseases. Other hypertensive rat models are being tested.

Recombinant neutral endopeptidase decreases oedema in the skin of burned guinea-pigs.

Oedema, due to increased vascular leakage postburn, cases significant problems for burn patients. The purpose of this study was to determine if local application of a recombinant neutral endopeptidase (rNEP) would reduce the increased vascular permeability caused by a burn. In a guinea-pig model, a single treatment of rNEP given immediately postburn significantly decreased burn-induced plasma extravasation. This rNEP effect was dependent upon both the dosage of the peptidase and its enzymatic activity. Additional experiments were consistent with the rNEP acting partly by degrading bradykinin, a mediator of increased vascular permeability postburn. These findings suggest that further study of rNEP as a possible treatment for oedema is warranted.