Macrophage-derived PDGF-B induces muscularization in murine and human pulmonary hypertension.

Excess macrophages and smooth muscle cells (SMCs) characterize many cardiovascular diseases, but crosstalk between these cell types is poorly defined. Pulmonary hypertension (PH) is a lethal disease in which lung arteriole SMCs proliferate and migrate, coating the normally unmuscularized distal arteriole. We hypothesized that increased macrophage platelet-derived growth factor-B (PDGF-B) induces pathological SMC burden in PH. Our results indicate that clodronate attenuates hypoxia-induced macrophage accumulation, distal muscularization, PH, and right ventricle hypertrophy (RVH). With hypoxia exposure, macrophage Pdgfb mRNA was upregulated in mice, and LysM­Cre mice carrying floxed alleles for hypoxia-inducible factor 1a, hypoxia-inducible factor 2a, or Pdgfb had reduced macrophage Pdgfb and were protected against distal muscularization and PH. Conversely, LysM­Cre von-Hippel Lindaufl/fl mice had increased macrophage Hifa and Pdgfb and developed distal muscularization, PH, and RVH in normoxia. Similarly, Pdgfb was upregulated in macrophages from human idiopathic or systemic sclerosis-induced pulmonary arterial hypertension patients, and macrophage-conditioned medium from these patients increased SMC proliferation and migration via PDGF-B. Finally, in mice, orotracheal administration of nanoparticles loaded with Pdgfb siRNA specifically reduced lung macrophage Pdgfb and prevented hypoxia-induced distal muscularization, PH, and RVH. Thus, macrophage-derived PDGF-B is critical for pathological SMC expansion in PH, and nanoparticle-mediated inhibition of lung macrophage PDGF-B has profound implications as an interventional strategy for PH.

Polymeric vehicles for nucleic acid delivery.

Polymeric vehicles are versatile tools for therapeutic gene delivery. Many polymers-when assembled with nucleic acids into vehicles-can protect the cargo from degradation and clearance in vivo, and facilitate its transport into intracellular compartments. Design options in polymer synthesis yield a comprehensive range of molecules and resulting vehicle formulations. These properties can be manipulated to achieve stronger association with nucleic acid cargo and cells, improved endosomal escape, or sustained delivery depending on the application. Here, we describe current approaches for polymer use and related strategies for gene delivery in preclinical and clinical applications. Polymer vehicles delivering genetic material have already achieved significant therapeutic endpoints in vitro and in animal models. From our perspective, with preclincal assays that better mimic the in vivo environment, improved strategies for target specificity, and scalable techniques for polymer synthesis, the impact of this therapeutic approach will continue to expand.

Synthetic Biology Category Wins the 350th Anniversary Merck Innovation Cup.

Over the past 350 years, Merck has developed science and technology especially in health care, life sciences, and performance materials. To celebrate so many productive years, Merck conducted a special expanded anniversary edition of the Innovation Cup in combination with the scientific conference Curious2018 - Future Insight in Darmstadt, Germany.

Tunability of Biodegradable Poly(amine- co-ester) Polymers for Customized Nucleic Acid Delivery and Other Biomedical Applications.

Gene therapy promises to treat diseases that arise from genetic abnormalities by correcting the underlying cause of the disease rather than treating the associated symptoms. Successful transfer of nucleic acids into cells requires efficient delivery vehicles that protect the cargo and can penetrate the appropriate cellular barriers before releasing their contents. Many viral vectors and synthetic polycationic vectors for nucleic acid delivery do not translate well from in vitro to in vivo applications due to their instability and toxicity. We synthesized and characterized a library of biocompatible low charge density polymers from a family of poly(amine- co-ester) (PACE) terpolymers produced via enzyme catalyzed polymerization. PACE polymers are highly customizable; we found that the terpolymer composition can be optimized to produce efficient transfection of various nucleic acids-including DNA plasmids, mRNA, and siRNA-in specific cell types with low toxicity. Our findings suggest that the unique tunability of PACEs offers new tools for gene therapy and other biomedical applications.

A "top-down" approach to actuate poly(amine-co-ester) terpolymers for potent and safe mRNA delivery.

Gene delivery is known to be a complicated multi-step biological process. It has been observed that subtle differences in the structure and properties of polymeric materials used for gene delivery can lead to dramatic differences in transfection efficiency. Therefore, screening of properties is pivotal to optimizing the polymer. So far, most polymeric materials are built in a "bottom-up" manner, i.e. synthesized from monomers that allow modification of polymer composition or structural factors. With this method, we previously synthesized and screened a library of biodegradable poly(amine-co-ester) (PACE) terpolymers for optimized DNA delivery. However, it can be tedious and time consuming to synthesize a polymer library for screening, particularly when small changes of a factor need to be tested, when multiple factors are involved, and when the effects of different factors are synergistic. In the present work, we evaluate the potential of PACE to deliver mRNA. After observing that mRNA transfection efficiency was highly dependent on both end group composition and molecular weight (MW) of PACE in a synergistic manner, we developed a "top-down" process we called actuation, to simultaneously vary these two factors. Some of the actuated PACE (aPACE) materials presented superior mRNA delivery properties compared to regular PACE, with up to a 106-fold-increase in mRNA transfection efficiency in vitro. Moreover, when aPACE was used to deliver mRNA coding for erythropoietin (EPO) in vivo, it produced high levels of EPO in the blood for up to 48 h without inducing systemic toxicity. This polymer constitutes a new delivery vehicle for mRNA-based treatments that provides safe yet potent protein production.

Assessment of the association between colchicine therapy and serious adverse events.

STUDY OBJECTIVE: As data that prompted a 2009 labeling change detailing contraindications, precautions, and dosing recommendations for the first branded colchicine product were limited to case reports of myotoxicity and blood dyscrasias ascribed to the drug, we sought to quantify the association of colchicine therapy with serious adverse outcomes in a cohort of insured patients. DESIGN: Case-control study. DATA SOURCE: Kaiser Permanente Colorado electronic data warehouses and electronic medical records. PATIENTS: Cases were patients with a creatine kinase (CK) level of at least 2000 U/L or who developed a clinically significant non-cancer-related blood dyscrasia (thrombocytopenia, neutropenia, leukopenia, aplastic anemia, or pancytopenia) between January 1, 2006, and June 30, 2009 (954 cases). Each case was matched to up to 10 controls by age, sex, and index date (date of the increased CK level or blood dyscrasia-supporting laboratory value). Controls were patients without elevated CK levels or blood dyscrasias who had a routine health maintenance examination during the same time period (index date was the date of their health maintenance examination [9007 controls]). MEASUREMENTS AND MAIN RESULTS: The primary study outcome was colchicine exposure, defined as a colchicine prescription purchase in the 100 days before the index date. The likelihood of colchicine exposure was examined with conditional logistic regression. Cases experienced a higher rate of previous colchicine exposure compared with controls (0.6% vs 0.2%, odds ratio 3.9, 95% confidence interval 1.4-10.7). In addition, cases had higher hospitalization rates (14.9% vs 5.0%, p<0.001), higher mean chronic disease scores (2.5 vs 0.0, p<0.001), and were more likely to have been exposed to drugs that may increase the risk of adverse events due to an interaction with a CYP3A4 inhibitor drug (6.9% vs 2.3%, p<0.001). CONCLUSION: Patients with confirmed elevations in CK level and/or blood dyscrasias had a higher rate of previous colchicine exposure, although low overall, and greater hospitalization rates and exposure to drugs that may increase the risk of adverse events compared with controls. These findings support the 2009 United States Food and Drug Administration labeling for the first branded colchicine product, cautioning use in patients with liver impairment or renal dysfunction and/or those receiving concurrent drugs that may increase risk of adverse events.

Blood pressure level attainment among patients with coronary artery disease and uncontrolled blood pressure.

STUDY OBJECTIVES: To determine the proportion of patients with coronary artery disease (CAD) and uncontrolled blood pressure who attained a blood pressure of less than 130/80 mm Hg, and to compare patient- and health system- specific characteristics and identify factors independently associated with attaining this blood pressure level. DESIGN: Retrospective, longitudinal, cohort study. SETTING: Health maintenance organization. PATIENTS: A cohort of 1380 patients (14%) who had uncontrolled blood pressure out of 9785 adults with established CAD enrolled in the Clinical Pharmacy Cardiac Risk Service. MEASUREMENTS AND MAIN RESULTS: Uncontrolled hypertension was defined as a mean of two consecutive blood pressure readings of 140/90 mm Hg or higher in 2006 or 2007, most proximal to December 31, 2007 (baseline). The cohort was followed from January 1, 2008-June 30, 2009 (follow-up). The follow-up blood pressure level was the mean of the last two consecutive blood pressure readings most proximal to June 30, 2009. Of the 1380 patients, 34.9% (482 patients), 34.0% (469), and 31.1% (429) attained a blood pressure below 130/80, 130/80-139/89, and 140/90 mm Hg or higher, respectively, at follow-up. Significantly more patients in the less than 130/80 mm Hg group were male, had Medicare insurance, had lower baseline systolic and/or diastolic blood pressures, and had a higher Chronic Disease Score compared with the other groups. For every additional clinic visit, there was a 3% increased likelihood of attaining a blood pressure below 130/80 mm Hg (adjusted odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.04). Patients experiencing a cardiac event during the follow-up period were approximately twice as likely to attain a blood pressure below 130/80 mm Hg (OR 1.97, 95% CI 1.04-3.77) compared with those who did not have a subsequent event. CONCLUSION: Despite systematic and aggressive treatment of blood pressure in patients with CAD and uncontrolled blood pressure, a minority of patients attained a blood pressure of less than 130/80 mm Hg. Considering that higher utilization of the health care system was associated with reaching this blood pressure level and that a similar number of therapeutic interventions in the groups resulted in variable success for blood pressure lowering, attaining a blood pressure level of less than 130/80 mm Hg may be difficult for some patients with CAD.

Attainment of low-density lipoprotein cholesterol goals in coronary artery disease.

BACKGROUND: The National Cholesterol Education Program Guidelines offer an optional low-density lipoprotein cholesterol (LDL-C) goal of less than 70 mg/dL for very high-risk patients with coronary artery disease (CAD). This study evaluated the extent to which this recommendation can be attained by the use of currently available lipid-lowering therapies. METHODS: A retrospective, cross-sectional study of patients in the Kaiser Permanente Colorado healthcare system 18 years of age or older with CAD and a predetermined LDL-C goal less than 70 mg/dL. The LDL-C most proximal, but within 1 year before April 1, 2008, was deemed the qualifying LDL-C and used to determine LDL-C goal attainment. Lipid-lowering medication(s) for those attaining goal and factors associated with failure to attain LDL-C goal also were identified. RESULTS: A total of 7427 patients were included in the study. A total of 3226 patients attained a LDL-C less than 70 mg/dL. The majority (92.4%) attaining goal were receiving statin monotherapy or in combination compared with 81.3% not at goal (P < .001). More than one-half attained goal on statin monotherapy with 70.7% at moderate- to high-potency doses and 87.4% on generically available statin. Nearly one-third attaining goal received statin in combination. Ezetimibe (70.6%) was most frequently used with statin. Factors independently associated with failure to attain a LDL-C less than 70 mg/dL were age younger than 65 years, patients not receiving statin, a history of creatine kinase elevation, and female sex. CONCLUSION: This study reports the greatest rate of LDL-C less than 70 mg/dL goal attainment in a very high-risk population with CAD to date. However, despite a system dedicated to aggressively treat to a LDL-C goal of less than 70 mg/dL, success in the majority is a challenge with the currently available therapies.

Relationship between haemoglobin A1C values and recurrent cardiac events: A retrospective, longitudinal cohort study.

OBJECTIVE: This study set out to analyse the impact of baseline glycosylated haemoglobin A1c (HbA1c) values on the incidence of recurrent cardiac events in patients prescribed optimal secondary prevention medications and receiving aggressive cardiac risk factor management. METHODS: This was a retrospective study conducted at Kaiser Permanente Colorado and included adults followed by a clinical pharmacy specialist-managed cardiac risk service (CPCRS) with an incident cardiac event and an HbA1c value measured within 1 year prior or 60 days after the incident cardiac event was identified. Cox proportional hazards models were constructed to assess the relationship between HbA1c levels and recurrent cardiac events (assessed as continuous and categorical measures) after adjustment for potential confounding variables. RESULTS: Of 5663 patients identified within an incident cardiac event between January 1999 and March 2005, 1270 (22.4%) patients had a baseline HbA1c value recorded. Of these 1270 patients, 215 (16.9%) had a recurrent cardiac event. Compared with the 'no recurrent event' cohort, the 'recurrent event' cohort were younger, less likely to have undergone an initial coronary artery bypass graft, and more likely to have undergone percutaneous coronary intervention with or without stent. The recurrent event cohort was also less likely to have purchased an HMG-CoA reductase inhibitor ('statin') [p = 0.043] at the time of the incident cardiac event. There was no significant difference in mean baseline HbA1c value between the cohorts. There were also no significant differences between the cohorts when categorized by baseline HbA1c <7% as referent compared with > or =7% to <8%, > or =8% to <9%, > or =9 to <10%, and > or =10%. Moreover, there was no significant difference between cohorts when HbA1c values <7% were compared with values >7% in the unadjusted analysis. Results remained non-significant after adjustment for sex, incident cardiac event type, baseline age, ss-blocker use, statin use and hyperlipidaemia. CONCLUSION: The results of this study suggest that an abnormal HbA1c is not predictive of recurrent cardiac events among patients with cardiovascular disease when other cardiovascular risk factors are being aggressively treated and appropriate secondary prevention medications are being taken. However, larger studies are warranted to validate these findings.