MO077: Systemic Therapy with a Single-Dose Kidney-Targeted Bioengineered VEGF Construct Improves Stenotic Kidney Hemodynamics in Experimental Renovascular Disease

BACKGROUND AND AIMS

We recently developed a construct of an elastin-like polypeptide fused to VEGF (ELP-VEGF) and showed its efficacy to target and protect the kidney after single systemic administration in a swine model of unilateral renovascular disease (RVD) via therapeutic angiogenesis. Despite a demonstrated renal efficacy, the possibility of off-target binding of VEGF to other organs and undesired effects exists. Thus, we augmented renal specificity by adding a kidney-targeting peptide (KTP) and showed that KTP-ELP accumulates in the kidney to a greater extent than ELP (rodents and swine). Furthermore, addition of KTP redirected ELP-VEGF, which was found at high levels in the liver, to the kidney (rodents). The current proof-of-concept study aims to define the renal therapeutic efficacy of the KTP-ELP-VEGF construct after systemic administration in RVD.

METHOD

RVD was induced in 12 pigs by unilateral renal artery stenosis and observed for 10 weeks. After 6 weeks, pigs were treated with a single IV dose of untargeted ELP-VEGF, KTP-ELP-VEGF (1 mg/kg, through ear vein) or placebo (n = 4 each). RBF, GFR and cortical perfusion were quantified in vivo using multi-detector CT before and 4 weeks after treatment/placebo. An additional four animals were used as normal controls.

RESULTS

Stenotic-kidney hemodynamics were similarly reduced in all RVD pigs 6 weeks after induction of renal artery stenosis. Administration of ELP-VEGF or KTP-ELP-VEGF led to significant improvements in RBF, GFR and cortical perfusion compared with pretreatment values, suggesting no interference with VEGF's biological activity. Notably, KTP-ELP-VEGF showed a slightly greater improvement in stenotic kidney hemodynamics than untargeted ELP-VEGF.

CONCLUSION

This study builds on our recent work and shows for the first time the biological activity and therapeutic efficacy of KTP-ELP-VEGF, expanding the potential of strategies using targeted renal treatments and offering the possibility of intra-renal and systemic routes of administration. The traits of KTP-ELP carriers strengthened drug-delivery strategies by minimizing off-target effects of VEGF or any other therapeutic cargo, which may help to extend applications to other forms of renal disease.

FC 064A RENAL-CARDIO INFLAMMATORY AXIS MEDIATES CARDIAC DYSFUNCTION IN CKD VIA IL-33-ST2: A NOVEL MECHANISM

Background and Aims

We developed a swine model of chronic kidney disease (CKD) that also display cardiac abnormalities associated with heart failure (HF). Inflammation contributes to progressive renal dysfunction and increases cardiovascular mortality of patients with CKD. Interleukin (IL)-33 is a tissue-derived nuclear cytokine from the IL family. IL-33 constitutively expressed but upregulated and released after cellular damage or necrotic cell death, acting as a pro-inflammatory cytokine. We hypothesize that IL-33 plays a prominent mechanistic role in renal-cardio pathophysiology in CKD.

Method

We induced CKD in 10 pigs via bilateral renovascular disease and dyslipidemia. We developed a renally-targeted biopolymer-fused peptide inhibitor of nuclear-factor kappa (NF-k)B (ELP-p50i) and show it blocks NFkB activity in vitro and in vivo. NF-kB is a key pro-inflammatory transcription factor upregulated in CKD and closely interacts with IL-33. Pigs were observed for 6 weeks, renal (multi-detector CT) and cardiac structure and function (echo) were quantified, then randomized to single intra-renal ELP-p50i or placebo (n=5 each), and studies repeated 8 weeks later. Blood was collected to measure circulating TNF-α, IL-33 and its specific decoy receptor soluble (s) ST2 (ELISA). Heart weights were measured after euthanasia, and renal and cardiac expression of ST2 and morphometric analyses were performed.

Results

Loss of renal function in CKD was accompanied by increased heart weight, left ventricular (LV) hypertrophy, diastolic dysfunction, abnormal LV strain, renal/cardiac fibrosis, circulating TNF-α, IL-33 but unchanged sST2, and increased renal/cardiac ST2 expression. Most of these changes were improved after intra-renal ELP-p50i and accompanied by augmented sST2, suggesting that inhibition of renal inflammation can attenuate cardiac abnormalities via augmented clearance of IL-33 (Figure).

Conclusion

Our study supports a prominent role for renal inflammation as a driving force for precursors of HF in CKD, proposing a renal-cardio inflammatory axis possibly mediated by NF-kB-TNF-α-IL-33/ST2 interactions. TNF-α can stimulate IL-33 as IL33 can activate NF-kB and TNF-α, extending this inflammatory loop in both the kidney and heart. We show that a translational renal anti-inflammatory strategy via targeted inhibition of renal NFkB inhibits this axis and improves renal and cardiac function, which may guide to new treatments targeting renal inflammation in CKD.

MO062CHRONIC KIDNEY DISEASE, INFLAMMATION, AND HEART FAILURE WITH PRESERVED EJECTION FRACTION: A RENAL-CARDIO AXIS?

Background and Aims

Inflammation contributes to progressive renal dysfunction and increases cardiovascular mortality of patients with chronic kidney disease (CKD). The association of CKD and heart failure with preserved ejection fraction (HFpEF) is observed in up to 50%, suggesting the possibility of a shared pathophysiology. CKD and HFpEF are commonly associated with inflammation. Using a novel swine model of CKD and HFpEF, we propose that a renal-cardio inflammatory axis drives diastolic dysfunction and HFpEF in CKD and that targeting renal inflammation will improve cardiac health and reduce cardiovascular risk.

Methods

We developed a biopolymer-fused peptide of nuclear-factor kappa (NFk)B (ELP-p50i) that we show it blocks its activity in vitro and in vivo. NFkB is a key pro-inflammatory transcription factor that is upregulated in CKD. To test our hypothesis, we induced CKD in 10 pigs via bilateral renovascular disease and dyslipidemia. Pigs were observed for 6 weeks, renal hemodynamics quantified (multi-detector CT), then randomized to single intra-renal ELP-p50i or placebo (n=5 each), and studies repeated 8 weeks later accompanied by echocardiographic assessment. Blood pressure was continuously measured (telemetry). Blood was collected to measure circulating TNF-α and biomarkers of HF (ANP, BNP). Furthermore, kidneys and hearts were used to quantify expression of factors involved in NFkB signaling.

Results

CKD led to a significant loss of renal function, accompanied by left ventricular hypertrophy and diastolic dysfunction with pEF, increased renal mRNA expression of TNF-α and canonical and non-canonical mediators of NFkB signaling, and elevated systemic TNF-α, ANP, and BNP, indicating renal and cardiac dysfunction. Most of these changes were improved after intra-renal ELP-p50i, although cardiac inflammatory signaling was unchanged (Figure) suggesting the kidney as a source of inflammation that can target the heart in CKD.

Conclusion

We show that a renal anti-inflammatory strategy via targeted inhibition of renal NFkB improves renal and cardiac function in CKD, suggesting an inflammatory renal-cardio axis. The translational pathological features of CKD and HFpEF combined with the predictive power of the model may contribute to advance the field towards new treatments targeting renal inflammation to reduce cardiovascular risk in CKD.

P0117DOSE ESCALATING TOXICOLOGY STUDY OF ELP-VEGF, A NOVEL BIOLOGIC FOR RENAL THERAPEUTIC ANGIOGENESIS

Background and Aims

Chronic renal disease, irrespective of the etiology, is hallmarked by renal microvascular rarefaction. This rarefaction is associated with a reduced bioavailability of the pro-angiogenic cytokine vascular endothelial growth factor (VEGF). Recently, we developed a therapeutic intervention for ischemic renal conditions using therapeutic angiogenesis – supplementing renal VEGF levels.

This was achieved by administration of a biopolymer-stabilized form of VEGF using a fusion protein between human VEGF-A121 and an elastin-like polypeptide carrier protein (ELP-VEGF). ELP-VEGF induced microvascular remodeling and increased microvascular density when administered intra-renally in swine models of unilateral renovascular disease (RVD) and chronic kidney disease (CKD), which was associated with improved renal function, reduced renal inflammation, and reduced renal fibrosis. Also, ELP-VEGF targeted the kidney when administered systemically and induced similar beneficial effects on renal function and renal vascular density. The therapeutic dose of ELP-VEGF in the swine models was 0.1 mg/kg when administered intra-renally and 1.0 mg/kg when administered intravenously. The aims of the present study were to determine the maximum tolerated dose of ELP-VEGF and assess its dose-related toxicity. We hypothesize that ELP-VEGF will not exhibit toxicity at therapeutic doses.

Method

A dose escalating toxicology experiment was performed in Sprague Dawley. Female rats were instrumented with either carotid catheters or carotid artery telemeters for blood pressure monitoring. After a recovery period, a baseline 24-hour urine sample was collected, and baseline glomerular filtration rate (GFR) was measured by monitoring FITC-sinistrin clearance via transdermal fluorescence. A single injection of saline control or ELP-VEGF (0.1, 1, 10, 100, or 200 mg/kg) was administered, and blood pressure was monitored by telemetry or by direct carotid arterial pressure measurements. Body weights were monitored daily throughout the study, and 24-hour urine collections and GFR measurements were repeated 7 and 14 days after protein injection. On day 14 after injection, blood was collected, one kidney was collected and fixed for histological examination, and the second kidney was perfused with Microfil vascular contrast agent for quantification of renal vascular density by micro-CT.

Results

ELP-VEGF caused no significant changes in body weight at any dose. At the highest doses there was an acute drop in blood pressure (20 – 30 mm Hg at 100 and 200 mg/kg dose, respectively) for approximately twenty minutes post-injection which then normalized. GFR was unchanged by ELP-VEGF at doses up to 100 mg/kg. However, GFR was significantly increased 14 days after treatment with 200 mg/kg ELP-VEGF (1.5 +/- 0.3 versus 2.7 +/- 0.3 mL/min/100 g body weight, p=0.0021). Plasma toxicology revealed no changes in markers of liver or kidney toxicity (AST, ALT, BUN, creatinine, LDH, bilirubin) at any dose or time point. Renal vascular density was unaffected by ELP-VEGF at doses up to 10 mg/kg. However, at 200 mg/kg ELP-VEGF, renal vascular density was significantly decreased for small (0 – 100 micron, p=0.0007) and intermediate (100 – 200 micron, p=0.028) sized vessels

Conclusion

ELP-VEGF has a proven therapeutic potential for treatment of RVD and CKD at therapeutic doses ranging from 0.1 – 1.0 mg/kg in swine models. Dose escalating toxicity assessment in rats found no effect of ELP-VEGF on body weight, blood pressure, plasma markers of liver and renal toxicity, GFR, or renal vascular density at these therapeutic doses. ELP-VEGF doses of 100 – 200 mg/kg caused transient hypotension immediately after the injection and were associated with increased GFR and loss of renal vascular density, possibly indicating renal damage at ultra-high doses. We conclude that the therapeutic window for ELP-VEGF is 100 – 1,000 times the effective therapeutic dose.

Placental origins of adverse pregnancy outcomes: potential molecular targets: an Executive Workshop Summary of the Eunice Kennedy Shriver National Institute of Child Health and Human Development

Although much progress is being made in understanding the molecular pathways in the placenta that are involved in the pathophysiology of pregnancy-related disorders, a significant gap exists in the utilization of this information for the development of new drug therapies to improve pregnancy outcome. On March 5-6, 2015, the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health sponsored a 2-day workshop titled Placental Origins of Adverse Pregnancy Outcomes: Potential Molecular Targets to begin to address this gap. Particular emphasis was given to the identification of important molecular pathways that could serve as drug targets and the advantages and disadvantages of targeting these particular pathways. This article is a summary of the proceedings of that workshop. A broad number of topics were covered that ranged from basic placental biology to clinical trials. This included research in the basic biology of placentation, such as trophoblast migration and spiral artery remodeling, and trophoblast sensing and response to infectious and noninfectious agents. Research findings in these areas will be critical for the formulation of the development of future treatments and the development of therapies for the prevention of a number of pregnancy disorders of placental origin that include preeclampsia, fetal growth restriction, and uterine inflammation. Research was also presented that summarized ongoing clinical efforts in the United States and in Europe that has tested novel interventions for preeclampsia and fetal growth restriction, including agents such as oral arginine supplementation, sildenafil, pravastatin, gene therapy with virally delivered vascular endothelial growth factor, and oxygen supplementation therapy. Strategies were also proposed to improve fetal growth by the enhancement of nutrient transport to the fetus by modulation of their placental transporters and the targeting of placental mitochondrial dysfunction and oxidative stress to improve placental health. The roles of microRNAs and placental-derived exosomes, as well as messenger RNAs, were also discussed in the context of their use for diagnostics and as drug targets. The workshop discussed the aspect of safety and pharmacokinetic profiles of potential existing and new therapeutics that will need to be determined, especially in the context of the unique pharmacokinetic properties of pregnancy and the hurdles and pitfalls of the translation of research findings into practice. The workshop also discussed novel methods of drug delivery and targeting during pregnancy with the use of macromolecular carriers, such as nanoparticles and biopolymers, to minimize placental drug transfer and hence fetal drug exposure. In closing, a major theme that developed from the workshop was that the scientific community must change their thinking of the pregnant woman and her fetus as a vulnerable patient population for which drug development should be avoided, but rather be thought of as a deprived population in need of more effective therapeutic interventions.

SU-E-I-67: Multi-Shot RESOLVE Compared to Single-Shot EPI Diffusion- Weighted MR Imaging Acquisition Scheme

PURPOSE

The purpose of this project was to configure the parameters for optimal comparison of image quality differences between the prototype imaging technique, read-out-segmented EPI multi-shot (RESOLVE) and the clinically used single-shot EPI (SS-EPI) MRI sequence for Diffusion Weighted Imaging (DWI) in a saline phantom, followed by a normal rat brain.

METHODS

Saline phantom (4.2 × 4.2 cm² ) and a rat brain were imaged on the 1.5T ESPREE (Siemens, Germany) MRI magnet using a wrist coil. Both the SS-EPI and RESOLVE DWI were optimized with equal imaging parameters such as slice thickness/slice gap = 3.0/0 mm, field of view = 210 mm, phase resolution = 100%, and diffusion b values = 0, 600 s/mm² while other parameters were given similar settings such as the base resolution, which had to be interpolated for the SS-EPI to 96i to match the RESOLVE as it was unable to be set at 192. Image quality was compared in terms of signal intensity, distortion, % ghosting and Apparent Diffusion Co-efficient (ADC) measurements from each sequence.

RESULTS

A marked enhancement of overall image quality with superior detail was observed in each of the scans from the RESOLVE sequence when compared to the SS-EPI. Comparing the efficiency of both sequences in terms of image quality, RESOLVE demonstrated a better stable image with minimal distortion and ghosting. The phantom dimensions obtained from RESOLVE images matched the actual dimensions perfectly. RESOLVE images had signal intensities significantly higher than (2.4×) the SS-EPI images (p=0.0008) and ∼0.6 % times less ghosting compared to SS-EPI (p=0.82) which also exhibited distortion with reduced phantom dimensions (4.05 × 3.28 cm) from original. The ADC values computed were almost identical to be (p=0.32) from SS-EPI (2.21mm² /sec) and RESOLVE (2.19mm² /sec).

CONCLUSIONS

The RESOLVE sequence has significantly superior image quality compared to SS-EPI at 1.5 T with reasonable scan times. DWI with RESLOVE acquisition scheme can be highly beneficial in obtaining distortion free images in routine clinical studies to characterize tumors and other pathological mechanisms with much greater detail than the current clinically used SS-EPI.

Perceptions of blindness related to smoking: a hospital-based cross-sectional study

AIMS

Smoking is associated with several serious eye diseases. Awareness of smoking and blindness, and its potential to act, as a stimulus to assist stopping smoking has not been investigated.

METHODS

A cross-sectional survey using a structured interview of adult patients attending district general hospital ophthalmology, general surgery, and orthopaedic clinics. The interview investigated the awareness and fear of blindness for three established smoking-related diseases, and a distractor condition (deafness), and the likelihood that smokers would quit on developing early signs of each condition.

RESULTS

Response was 89.1% (358/402). In all, 183 (51.1%) of responders were male and 175 (48.9%) female. Only 9.5% of patients believed that smoking was definitely or probably a cause of blindness, compared with 92.2% for lung cancer, 87.6% for heart disease, and 70.6% for stroke. Patients ranked their fear of each of the five conditions, scoring five for the most feared and one for the least feared. Patients were significantly (P<0.01) less fearful of blindness (mean score 2.80) than lung cancer (3.89), heart disease (3.58), and stroke (3.35). About one-half of smokers stated that they would definitely or probably quit smoking if they developed early signs of blindness or the three established smoking-related conditions, with no significant differences in proportions for these four conditions.

CONCLUSION

The findings suggest that awareness of the risk of blindness from smoking is low, but that the fear of blindness is as compelling a motivation to quit as fear of lung cancer, heart disease, and stroke. The link between smoking and eye disease should be publicised to help reduce smoking prevalence.

Peritoneal dialysis: a temporizing means for hemodialysis patients with subdural hematomas

Subdural hematoma has a higher mortality rate with hemodialysis patients than the normal population. One reason for this is the coagulation abnormalities of hemodialyzed patients. One case of a successfully treated subdural hematoma in a chronic peritoneal dialysis patient is presented. Changing the mode of dialysis from hemodialysis to peritoneal dialysis in a patient suspected of having a subdural hematoma may be beneficial in improving overally survival.