Aims
Endothelial‐derived epoxyeicosatrienoic acids may regulate vascular tone and are metabolized by soluble epoxide hydrolase enzymes (sEH). GSK2256294 is a potent and selective sEH inhibitor that ...was tested in two phase I studies.
Methods
Single escalating doses of GSK2256294 2–20 mg or placebo were administered in a randomized crossover design to healthy male subjects or obese smokers. Once daily doses of 6 or 18 mg or placebo were administered for 14 days to obese smokers. Data were collected on safety, pharmacokinetics, sEH enzyme inhibition and blood biomarkers. Single doses of GSK2256294 10 mg were also administered to healthy younger males or healthy elderly males and females with and without food. Data on safety, pharmacokinetics and biliary metabolites were collected.
Results
GSK2256294 was well‐tolerated with no serious adverse events (AEs) attributable to the drug. The most frequent AEs were headache and contact dermatitis. Plasma concentrations of GSK2256294 increased with single doses, with a half‐life averaging 25–43 h. There was no significant effect of age, food or gender on pharmacokinetic parameters. Inhibition of sEH enzyme activity was dose‐dependent, from an average of 41.9% on 2 mg (95% confidence interval CI –51.8, 77.7) to 99.8% on 20 mg (95% CI 99.3, 100.0) and sustained for up to 24 h. There were no significant changes in serum VEGF or plasma fibrinogen.
Conclusions
GSK2256294 was well‐tolerated and demonstrated sustained inhibition of sEH enzyme activity. These data support further investigation in patients with endothelial dysfunction or abnormal tissue repair, such as diabetes, wound healing or COPD.
Circulating tumor cells (CTCs) play a fundamental role in cancer progression. However, in mice, limited blood volume and the rarity of CTCs in the bloodstream preclude longitudinal, in-depth studies ...of these cells using existing liquid biopsy techniques. Here, we present an optofluidic system that continuously collects fluorescently labeled CTCs from a genetically engineered mouse model (GEMM) for several hours per day over multiple days or weeks. The system is based on a microfluidic cell sorting chip connected serially to an unanesthetized mouse via an implanted arteriovenous shunt. Pneumatically controlled microfluidic valves capture CTCs as they flow through the device, and CTC-depleted blood is returned back to the mouse via the shunt. To demonstrate the utility of our system, we profile CTCs isolated longitudinally from animals over 4 days of treatment with the BET inhibitor JQ1 using single-cell RNA sequencing (scRNA-Seq) and show that our approach eliminates potential biases driven by intermouse heterogeneity that can occur when CTCs are collected across different mice. The CTC isolation and sorting technology presented here provides a research tool to help reveal details of how CTCs evolve over time, allowing studies to credential changes in CTCs as biomarkers of drug response and facilitating future studies to understand the role of CTCs in metastasis.
Protein-based methods of siRNA delivery are capable of uniquely specific targeting, but are limited by technical challenges such as low potency or poor biophysical properties. Here, we engineered a ...series of ultra-high affinity siRNA binders based on the viral protein p19 and developed them into siRNA carriers targeted to the epidermal growth factor receptor (EGFR). Combined in trans with a previously described endosome-disrupting agent composed of the pore-forming protein Perfringolysin O (PFO), potent silencing was achieved in vitro with no detectable cytotoxicity. Despite concerns that excessively strong siRNA binding could prevent the discharge of siRNA from its carrier, higher affinity continually led to stronger silencing. We found that this improvement was due to both increased uptake of siRNA into the cell and improved pharmacodynamics inside the cell. Mathematical modeling predicted the existence of an affinity optimum that maximizes silencing, after which siRNA sequestration decreases potency. Our study characterizing the affinity dependence of silencing suggests that siRNA-carrier affinity can significantly affect the intracellular fate of siRNA and may serve as a handle for improving the efficiency of delivery. The two-agent delivery system presented here possesses notable biophysical properties and potency, and provide a platform for the cytosolic delivery of nucleic acids.
Background
Circulating levels of chemerin are significantly higher in hypertensive patients and positively correlate with blood pressure. Chemerin activates chemokine‐like receptor 1 (CMKLR1 or ...ChemR23) and is proposed to activate the “orphan” G‐protein‐coupled receptor 1 (GPR1), which has been linked with hypertension. Our aim was to localize chemerin, CMKLR1, and GPR1 in the human vasculature and determine whether 1 or both of these receptors mediate vasoconstriction.
Methods and Results
Using immunohistochemistry and molecular biology in conduit arteries and veins and resistance vessels, we localized chemerin to endothelium, smooth muscle, and adventitia and found that CMKLR1 and GPR1 were widely expressed in smooth muscle. C9 (chemerin149–157) contracted human saphenous vein (pD2=7.30±0.31) and resistance arteries (pD2=7.05±0.54) and increased blood pressure in rats by 9.1±1.0 mm Hg at 200 nmol. Crucially, these in vitro and in vivo vascular actions were blocked by CCX832, which we confirmed to be highly selective for CMKLR1 over GPR1. C9 inhibited cAMP accumulation in human aortic smooth muscle cells and preconstricted rat aorta, consistent with the observed vasoconstrictor action. Downstream signaling was explored further and, compared to chemerin, C9 showed a bias factor=≈5000 for the Gi protein pathway, suggesting that CMKLR1 exhibits biased agonism.
Conclusions
Our data suggest that chemerin acts at CMKLR1, but not GPR1, to increase blood pressure. Chemerin has an established detrimental role in metabolic syndrome, and these direct vascular actions may contribute to hypertension, an additional risk factor for cardiovascular disease. This study provides proof of principle for the therapeutic potential of selective CMKLR1 antagonists.
Acriflavine, a fluorescent drug previously used for bacterial and trypanosomal infections, reduces hypoxia-inducible factor-1 (HIF-1) and HIF-2 transcriptional activity. In mice with oxygen-induced ...ischemic retinopathy, intraocular or intraperitoneal injections of acriflavine caused dose-dependent suppression of retinal neovascularization (NV) and significantly reduced expression of HIF-1-responsive genes. Intraocular injection of 100 ng caused inner retina fluorescence within 1 h that was seen throughout the entire retina between 1 and 5 days, and at 7 days after injection, strongly suppressed choroidal NV at Bruch’s membrane rupture sites. After suprachoroidal injection of 300 ng in rats, there was retinal fluorescence in the quadrant of the injection at 1 h that spread throughout the entire retina and choroid by 1 day, was detectable for 5 days, and dramatically reduced choroidal NV 14 days after rupture of Bruch’s membrane. After topical administration of acriflavine in mice, fluorescence was seen in the retina and retinal pigmented epithelium within 5 min and was detectable for 6–12 h. Administration of 0.5% drops to the cornea twice a day significantly reduced choroidal NV in mice. Electroretinographic b-wave amplitudes were normal 7 days after intravitreous injection of 100 ng of acriflavine in mice, showed mild threshold reductions at highest stimulus intensities after injection of 250 ng, and more extensive changes after injection of 500 ng. These data provide additional evidence for an important role for HIF-1 in retinal and choroidal NV and suggest that acriflavine can target HIF-1 through a variety of modes of administration and has good potential to provide a novel therapy for retinal and choroidal vascular diseases.
Key message
Acriflavine, an inhibitor of HIF-1, suppresses retinal and choroidal neovascularization.
HIF-1 plays a critical role in ocular neovascularization.
Acriflavine’s fluorescence provides a mean to track its entry and exit from the retina.
Acriflavine has therapeutic potential for the treatment of ocular neovascularization.
This paper focuses on the assessment of legislative considerations and local perceptions of equity in Vietnam's Payments for Forest Ecosystem Services scheme (PFES). Equity perceptions are powerful ...determinants of human behaviour and, consequently, many environmental conflicts arise from contested visions of what constitutes as ‘equitable’ environmental management. Therefore, equity can play an instrumental role in shaping outcomes of PFES schemes. This paper analyzes how contextual, procedural and distributive equity considerations are reflected in national PFES legislation and implementation, how equity outcomes are perceived locally, and whether local perceptions match legislative considerations. We reviewed national legislation and government reports, conducted expert interviews on the national and provincial level, as well as surveys, focus group discussions, and in-depth interviews on the local level. Our findings reveal that equity outcomes are very much affected by contextual factors, such as how the Forest Land Allocation regulation determines the distribution of use rights. In the implementation of PFES national aspirations and rationales of equity as outlined in legislation were not met due to technical constraints, financial costs, and social and institutional conflicts. The implementation on the ground contrasts with local interests. Our results show that on the local level the preference for a distributive equity principle is very much influenced by the degree of transparency of the payment distribution process. The prevailing perceptions of equitable benefit distribution by local PFES participants correspond to a merit-based principle of compensation for the effort of forest protection.
The aim of this study is to describe the technique of subpalpebral antibiotic lavage (SAL), which is a highly therapeutic, efficient, and cost-effective method for managing severe bacterial ...keratitis.
This case report describes a 26-year-old woman with severe bacterial keratitis in the right eye due to contact lens overwear, with progressive corneal thinning, a hypopyon, impending perforation, and marked visual loss to perception of light despite treatment with intensive topical antibiotics. This was managed with SAL that involves the insertion of a cannula transcutaneously into the upper conjunctival fornix to provide continuous antibiotic irrigation of the ocular surface.
By 11 weeks after presentation, the cornea and anterior chamber appeared clinically quiescent, and visual acuity improved to 20/40 corrected in the right eye.
Bacterial keratitis is a potentially blinding condition for which contact lens wear is an important risk factor. Most cases are successfully managed with topical medications; however, in cases of treatment failure, a second-line approach such as SAL can be sight-saving. SAL uses readily available equipment for the delivery of high concentrations of antibiotics to the ocular surface, thus increasing therapeutic efficacy and reducing nursing staff workload. Despite its advantages, the literature reveals apparent underutilization of this technique.
Blood phenotypes are defined by the presence or absence of specific blood group antigens at the red blood cell (RBC) surface, due to genetic polymorphisms among individuals. The recent development of ...genomic and proteomic approaches enabled the characterization of several enigmatic antigens. The choline transporter‐like protein CTL2 encoded by the SLC44A2 gene plays an important role in platelet aggregation and neutrophil activation. By investigating alloantibodies to a high‐prevalence antigen of unknown specificity, found in patients with a rare blood type, we showed that SLC44A2 is also expressed in RBCs and carries a new blood group system. Furthermore, we identified three siblings homozygous for a large deletion in SLC44A2, resulting in complete SLC44A2 deficiency. Interestingly, the first‐ever reported SLC44A2‐deficient individuals suffer from progressive hearing impairment, recurrent arterial aneurysms, and epilepsy. Furthermore, SLC44A2null individuals showed no significant platelet aggregation changes and do not suffer from any apparent hematological disorders. Overall, our findings confirm the function of SLC44A2 in hearing preservation and provide new insights into the possible role of this protein in maintaining cerebrovascular homeostasis.
Synopsis
Homozygous deletion in the SLC44A2 gene was identified in three siblings with a rare blood phenotype. SLC44A2 was confirmed to be essential in the physiology of hearing in humans, but dispensable for erythropoiesis and platelet aggregation.
SLC44A2, a choline transporter‐like protein (CTL2), underlies a novel human blood group system.
A missense mutation in SLC44A2 encodes a new red cell antigen, RIF, and a large deletion is responsible for a null phenotype (VER‐).
New anti‐SLC44A2 alloantibodies, anti‐RIF and anti‐VER, induce neutrophil adhesion to endothelial cells and could be involved in transfusion‐related acute lung injury (TRALI).
SLC44A2null individuals suffer from hearing impairment and recurrent intracranial aneurysms, but are not associated with neither apparent erythroid nor platelet disorders.
Homozygous deletion in the SLC44A2 gene was identified in three siblings with a rare blood phenotype. SLC44A2 was confirmed to be essential in the physiology of hearing in humans, but dispensable for erythropoiesis and platelet aggregation.
Abstract
Despite the projected sharpest decline in remittances in history due to the global economic crisis induced by the COVID-19 pandemic, remittances are expected to remain an important source of ...external financing for many developing countries. The Philippines is among the top five recipients of remittances worldwide, while outmigration is an important livelihood strategy for rural communities in the country due to rapid population growth, poor employment opportunities, and scarce agricultural land. Migration and remittances can influence smallholder land use with potential implications for forest resource use through an impact on household income and household decisions on local activities. However, little attention has been paid in previous research to how remittances relate to changes in rural households’ land use and their implications for forests. The goal of this study is to investigate the links between the inflow of both international and internal remittances and rural households’ land use in forested landscapes in the Philippines. In order to do that, we use the data from 1024 household surveys and an instrumental variable approach to investigate the impact of remittances on fuelwood use and on the area cultivated by perennials and cereals. The findings of this study show that remittances positively influence the size of land planted by perennials and reduce households’ reliance on fuelwood use. Our findings provide an improved understanding of the links between migration—remittances—natural resource management, which will become especially relevant as countries struggle to deal with the economic fallout associated with COVID-19. We argue that demographic policy measures should play a bigger role in land use, land use change, and forestry negotiations than before. Moreover, global sustainability agendas such as the sustainable development goals should recognize the impacts of migration on natural resources to help bridge the gap between developmental and environmental goals.
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