Development of a long-acting relaxin analogue, LY3540378, for treatment of chronic heart failure.

BACKGROUND AND PURPOSE: Chronic heart failure, a progressive disease with limited treatment options currently available, especially in heart failure with preserved ejection fraction (HFpEF), represents an unmet medical need as well as an economic burden. The development of a novel therapeutic to slow or reverse disease progression would be highly impactful to patients and society. Relaxin-2 (relaxin) is a human hormone regulating cardiovascular, renal, and pulmonary adaptations during pregnancy. A short-acting recombinant relaxin, Serelaxin, demonstrated short-term heart failure symptom relief and biomarker improvement in acute heart failure trials. Here, we present the development of a long-acting relaxin analogue to be tested in the treatment of chronic heart failure. EXPERIMENTAL APPROACH: LY3540378 is a long-acting protein therapeutic composed of a human relaxin analogue and a serum albumin-binding VHH domain. KEY RESULTS: LY3540378 is a potent agonist of the relaxin family peptide receptor 1 (RXFP1) and maintains selectivity against RXFP2/3/4 comparable to native relaxin. The half-life of LY3540378 in preclinical species is extended through high affinity binding of the albumin-binding VHH domain to serum albumin. When tested in a single dose administration, LY3540378 elicited relaxin-mediated pharmacodynamic responses, such as reduced serum osmolality and increased renal blood flow in rats. In an isoproterenol-induced cardiac hypertrophy mouse model, treatment with LY3540378 significantly reduced cardiac hypertrophy and improved isovolumetric relaxation time. In a monkey cardiovascular safety study, there were no adverse observations from administration of LY3540378. CONCLUSION AND IMPLICATIONS: LY3540378 demonstrated to be a suitable clinical development candidate, and is progressing in clinical trials.

Misdiagnosis of Third Nerve Palsy.

BACKGROUND: This study identifies the diagnostic errors leading to misdiagnosis of 3rd nerve palsy and to aid clinicians in making this diagnosis. The objective of this article is to determine the incidence of misdiagnosis of 3rd cranial nerve palsy (3rd nerve palsy) among providers referring to a tertiary care neuro-ophthalmology clinic and to characterize diagnostic errors that led to an incorrect diagnosis. METHODS: This was a retrospective clinic-based multicenter cross-sectional study of office encounters at 2 institutions from January 1, 2014, to January 1, 2017. All encounters with scheduling comments containing variations of "3rd nerve palsy" were reviewed. Patients with a documented referral diagnosis of new 3rd nerve palsy were included in the study. Examination findings, including extraocular movement examination, external lid examination, and pupil examination, were collected. The final diagnosis was determined by a neuro-ophthalmologist. The Diagnosis Error Evaluation and Research (DEER) taxonomy tool was used to categorize the causes of misdiagnosis. Seventy-eight patients referred were for a new diagnosis of 3rd nerve palsy. The main outcome measure was the type of diagnostic error that led to incorrect diagnoses using the DEER criteria as determined by 2 independent reviewers. Secondary outcomes were rates of misdiagnosis, misdiagnosis rate by referring specialty, and examination findings associated with incorrect diagnoses. RESULTS: Of 78 patients referred with a suspected diagnosis of 3rd nerve palsy, 21.8% were determined to have an alternate diagnosis. The most common error in misdiagnosed cases was failure to correctly interpret the physical examination. Ophthalmologists were the most common referring provider for 3rd nerve palsy, and optometrists had the highest overdiagnosis rate of 3rd nerve palsy. CONCLUSIONS: Misdiagnosis of 3rd nerve palsy was common. Performance and interpretation of the physical examination were the most common factors leading to misdiagnosis of 3rd nerve palsy.

Failure to Obtain Urgent Arterial Imaging in Acute Third Nerve Palsies.

BACKGROUND: Isolated third nerve palsy may indicate an expanding posterior communicating artery aneurysm, thus necessitating urgent arterial imaging. This study aims to assess the rate and duration of delays in arterial imaging for new isolated third nerve palsies, identify potential causes of delay, and evaluate instances of delay-related patient harm. METHODS: In this cross-sectional study, we retrospectively reviewed 110 patient charts (aged 18 years and older) seen between November 2012 and June 2020 at the neuro-ophthalmology clinic and by the inpatient ophthalmology consultation service at a tertiary institution. All patients were referred for suspicion of or had a final diagnosis of third nerve palsy. Demographics, referral encounter details, physical examination findings, final diagnoses, timing of arterial imaging, etiologies of third nerve palsy, and details of patient harm were collected. RESULTS: Of the 110 included patients, 62 (56.4%) were women, 88 (80%) were white, and the mean age was 61.8 ± 14.6 years. Forty (36.4%) patients received arterial imaging urgently. Patients suspected of third nerve palsy were not more likely to be sent for urgent evaluation (P = 0.29) or arterial imaging (P = 0.082) than patients in whom the referring doctor did not suspect palsy. Seventy-eight of 95 (82%) patients with a final diagnosis of third nerve palsy were correctly identified by referring providers. Of the 20 patients without any arterial imaging before neuro-ophthalmology consultation, there was a median delay of 24 days from symptom onset to imaging, and a median delay of 12.5 days between first medical contact for their symptoms and imaging. One patient was harmed as a result of delayed imaging. CONCLUSIONS: Third nerve palsies were typically identified correctly, but referring providers failed to recognize the urgency of arterial imaging to rule out an aneurysmal etiology. Raising awareness of the urgency of arterial imaging may improve patient safety.

Visual Outcomes in Presumed Congenital Foveal Toxoplasmosis.

PURPOSE: Congenital macular lesions attributed to toxoplasmosis may limit potential visual acuity. The appearance and location of these scars may cause physicians to overlook associated amblyopia. This study reviews the visual outcomes and benefits of amblyopia therapy in children with foveal toxoplasmosis scars. DESIGN: Retrospective observational case series. METHODS: Setting: Single center. PATIENT POPULATION: Children with presumed foveal toxoplasmosis scars who underwent amblyopia treatment. MAIN OUTCOME MEASURE: Charts were reviewed for amblyopia treatment, fundus photographs, optical coherence tomography (OCT), and visual acuity. RESULTS: Median age at presentation was 2.8 years and median follow-up was 6.2 years. Occlusion therapy was undertaken in 9 patients. Median duration of occlusion therapy was 1.7 years. Six patients improved with occlusion therapy (average 4.6 lines gained on optotype acuity). Final visual acuity ranged from 20/25 to 20/250, with 6 of 8 patients better than 20/80. OCT confirmed macular scars in 5 patients, with varying degrees of foveal architecture disruption. CONCLUSION: Despite the striking appearance of the lesions in patients with presumed foveal toxoplasmosis, visual potential may be better than expected. The appearance of the lesions is not always predictive of visual outcome. A trial of occlusion therapy to treat amblyopia should be initiated in these patients to ensure that they reach their maximal visual potential.

Identification of New Mono/Dihydroxynaphthoquinone as Lead Agents That Inhibit the Growth of Refractive and Triple-Negative Breast Cancer Cell Lines.

Human epidermal growth factor receptor 2 (HER2) is overexpressed in nearly 20-30% of breast cancers and is associated with metastasis resulting in poor patient survival and high recurrence. The dual EGFR/HER2 kinase inhibitor lapatinib has shown promising clinical results, but its limitations have also led to the resistance and activation of tumor survival pathways. Following our previous investigation of quinones as HER2 kinase inhibitors, we synthesized several naphthoquinone derivatives that significantly inhibited breast tumor cells expressing HER2 and trastuzumab-resistant HER2 oncogenic isoform, HER2Δ16. Two of these compounds were shown to be more effective than lapatinib at the inhibition of HER2 autophosphorylation of Y1248. Compounds 7 (5,8-dihydroxy-2-methylnaphthalene-1,4-dione) and 9 (2-(bromomethyl)-5,8-dihydroxynaphthalene-1,4-dione) inhibited HER2-expressing MCF-7 cells (IC50 0.29 and 1.76 µM, respectively) and HER2Δ16-expressing MCF-7 cells (IC50 0.51 and 1.76 µM, respectively). Compound 7 was also shown to promote cell death in multiple refractory breast cancer cell lines with IC50 values ranging from 0.12 to 2.92 µM. These compounds can function as lead compounds for the design of a new series of nonquinonoid structural compounds that can maintain a similar inhibition profile.

Retrospective Evaluation of the Impact of a Geriatric Trauma Institute on Fragility Hip Fracture Patient Outcomes.

BACKGROUND: Fragility hip fractures occur in the older than 65-year population at an alarming rate. It is estimated that 260,000 hip fractures occur annually. Patient outcomes following hip fractures are devastating. One of every 5 patients dies within 1 year of injury, and 1 of 3 remains in a nursing home for years after the injury. Published literature recommends an interdisciplinary approach to caring for hip-fractured patients and expediting surgery to improve outcomes. PURPOSE: The purpose of this study was to retrospectively evaluate the impact of the Geriatric Trauma Institute (GTI) on fragility hip fracture patient outcomes. Specific outcomes included length of stay (LOS), length of time from emergency department (ED) arrival to operating room (OR), complication rate, and discharge destination. METHODS: This study is a single-center pre- and post-retrospective chart review. Data were collected using database queries within the hospital system. Pre-GTI (n = 326) patients older than 65 years with International Classification of Disease, Ninth Revision (ICD-9) codes 820.0-820.9 (hip fractures) admitted to either a primary care physician or orthopaedic surgeon service between April 1, 2011, and April 1, 2013, were compared with post-GTI (n = 245) patients older than 65 years with ICD-9 codes 820.0-820.9 (hip fractures) admitted to trauma services (GTI) between May 1, 2013, and May 1, 2015. Descriptive statistics including demographic data (age, sex) and comparison of outcomes (LOS, ED to OR time, complications, and disposition) across the groups using standard analysis of variance (ANOVA) and correlation techniques. RESULTS: No statistical difference was found between groups for age, sex, or time from ED to OR pre- versus post-time period using one-way ANOVA, F(1,569) = 1.08, p = .30. The complication rate was calculated pre- and post-GTI and compared using the 2-proportion z-test. The difference between the pre-GTI group (16.6%; 54 of 326 patients) and the post-GTI group (9.4%; 23 of 245 patients) was statistically significant, p = .013. Mean LOS was statistically significantly higher in the pre-GTI group (M = 5) than in the post-GTI group (M = 5.2), U = 33,55, z = -3.32, p = .001. No statistical significance was found between pre- and postdischarge destination, χ(4) = .4.82, p = .307; likelihood ratio test, χ(4) = .5.19, p = .269. CONCLUSIONS: This retrospective pre- and post-GTI chart review demonstrates the effectiveness of a multidisciplinary team approach in decreasing complications and LOS for fragility hip-fractured patients. A team approach to the care of these patients improves outcomes and quality of life.

Optimizing the antisepsis protocol: Effectiveness of 3 povidone-iodine 1.0% applications versus a single application of povidone-iodine 5.0.

PURPOSE: To determine the minimum effective concentration of povidone-iodine that reduces the bacterial load by 3-log10, the U.S. Food and Drug Administration requirement for antiseptic agents, and to study alternative dosing schedules of povidone-iodine to optimize its bactericidal effect. SETTING: Microbiology Laboratory, Evanston Hospital, Evanston, Illinois, USA. DESIGN: Experimental study. METHODS: A standard 0.5 McFarland solution of Staphylococcus epidermidis was applied to blood agar plates. The plates were treated with a single application of povidone-iodine solutions from 10.0% to 0.1% to define the range of interest. Another set of plates received 3 applications of various povidone-iodine solutions. Microbial growth was evaluated after 24 hours. Standard deviations with 99.0% and 99.9% confidence intervals for each concentration were estimated and used to estimate the minimum concentration that reduced the colony counts by at least 3-log10. RESULTS: Povidone-iodine at 2.5% and higher concentrations was effective in eliminating S epidermidis with a single application. Three 30-second applications of povidone-iodine at concentrations of 0.7% and higher resulted in at least a 3-log10 reduction of colonies. CONCLUSIONS: Povidone-iodine 5.0% has been the standard of care for preoperative ocular antisepsis for 3 decades. Povidone-iodine 0.7% was as effective as a bactericidal agent when applied multiple times. This suggests povidone-iodine 1.0%, applied in three 30-second applications for preoperative surface disinfection might be as effective for preoperative antisepsis.

Ortho-Methylarylamines as Time-Dependent Inhibitors of Cytochrome P450 1A1 Enzyme.

BACKGROUND: Members of the cytochrome P450 1A family metabolize many procarcinogens such as polycyclicaromatic hydrocarbons and heterocyclic amines. Inactivation of these enzymes is a prerequisite for cancer prevention and treatment in certain cases. Mechanism-based inhibition (time and co-factor dependent) is an effective method for the inactivation of these enzymes. Our recent study on emodin analogs revealed an anthraquinone with ortho-methylarylamine moiety that exhibited timedependent inhibition of P450 enzymes 1A1 and 1A2. METHODS: To determine whether the amino group or the methyl group or both were responsible for the time-dependent inhibition of these enzymes, a set of eleven compounds containing the orthomethylarylamine moiety were identified through a database search, and studied for the inhibition of the P450 enzymes 1A1, 1A2, 2A6 and 2B1. Our earlier studies on carbazole derivatives provided us with highly selective P450 1A2 inhibitors. Glycine scanning studies were performed on the docked proteinligand complexes of compounds 1-20 in order to understand the contribution of different protein residues towards the ligand binding. RESULTS: Four compounds were found to cause selective time-dependent inhibition of P450 1A1 with KI values ranging from 0.24 to 8.25 mM. These compounds exhibited only direct inhibition of P450 1A2. Molecular modeling studies of these molecules indicated that the shapes of the molecules, their binding modes, and the methyl substituent in close proximity (4.5-5.7 Å) to the heme-Fe all contributed to their selective time-dependent inhibition activity on P450 1A1. Glycine scanning studies for P450 1A1 indicated that ligand interaction with Phe123 was the strongest binding contributor and similar studies for P450 1A2 indicated that ligand interactions with the phenylalanine residues 226 and 260 were the largest binding contributors. CONCLUSION: Four compounds have been identified that exhibit selective time-dependent inhibition of P450 1A1. Modeling studies have indicated that the proximity of the aromatic methyl group to the heme-Fe could be the main contributor for time-dependent inhibition. Future studies will focus on the confirmation of the involvement of the aromatic methyl group in enzyme inactivation.

Identification of quinones as novel PIM1 kinase inhibitors.

PIM1 is a proto-oncogene encoding the serine/threonine PIM1 kinase. PIM1 kinase plays important roles in regulating aspects of cell cycle progression, apoptosis resistance, and has been implicated in the development of such malignancies as prostate cancer and acute myeloid leukemia among others. Knockout of PIM1 kinase in mice has been shown to be non-lethal without any obvious phenotypic changes, making it an attractive therapeutic target. Our investigation of anthraquinones as kinase inhibitors revealed a series of quinone analogs showing high selectivity for inhibition of the PIM kinases. Molecular modeling studies were used to identify key interactions and binding poses of these compounds within the PIM1 binding pocket. Compounds 1, 4, 7 and 9 inhibited the growth of DU-145 prostate cancer cell lines with a potency of 8.21µM, 4.06µM, 3.21µM and 2.02µM.

Novel functionalized 5-(phenoxymethyl)-1,3-dioxane analogs exhibiting cytochrome P450 inhibition: a patent evaluation WO2015048311 (A1).

Cytochrome P450's (CYP's) constitute a diverse group of over 500 monooxygenase hemoproteins, catalyzing transformations that involve xenobiotic metabolism, steroidogenesis and other metabolic processes. Over-production of the steroid hormone cortisol is implicated in the progression of diseases such as diabetes, heart failure and hypertension, stroke, Cushing's syndrome, obesity and renal failure, among others. The biosynthesis of cortisol involves a cascade of cholesterol metabolizing reactions regulated through three major CYP proteins: 17α-hydroxylase-C17/20-lyase (CYP17), 21-hydroxylase (CYP21), and 11ß-hydroxylase (CYP11B1). Excess activities of these enzymes are linked to the progression of malignancies including prostate, breast, ovarian, and uterine cancers. A series of novel functionalized dioxane analogs have been developed and recently patented as CYP17, CYP21, and CYP11B1 inhibitors, which lead to the modulation of cortisol production as a method for treating, delaying, slowing, and inhibiting the implicated diseases. The findings disclosed in this patent have been analyzed and compared with the literature data on inhibitors of CYP17, CYP21, and CYP11B1. The compiled data provide insight into the novel functionality of the compounds described in the patent. In this regard, an objective opinion on the effectiveness and novel biochemistry of these compounds in comparison to current CYP inhibitors used in the treatment of cortisol-related diseases is presented in this paper.

Virtual Visits: Managing prenatal care with modern technology.

PURPOSE: To implement and evaluate a novel model of prenatal care for low-risk pregnant women that intersperses in-person physician visits with nurse practitioner visits conducted via videoconference. METHODS: This Quality Improvement initiative gave low-risk pregnant women the option of enrolling in a Traditional (N = 941) or Virtual Visit (N = 117) track for their prenatal care. Traditional patients had 14 physician visits and a postpartum visit. Virtual Visit patients had nine physician visits, five prenatal videoconference visits, and a 2-week postpartum videoconference visit. Measured outcomes include demographic variables, pregnancy and birth outcomes, and use of the health system. Logistic regression was used to assess demographic factors affecting track enrollment decisions. Multivariate logistic regression and ANCOVA methods were used to evaluate pregnancy and birth outcomes, adjusting for relevant confounding variables. RESULTS: Women enrolling in the Virtual Visit track were twice as likely to be partnered (p = 0.03) and not enrolled in government supplemental nutrition assistance (p = 0.01). They were seven times as likely to have been pregnant at least once before this enrollment (p < 0.001). Although a significantly higher percentage of Virtual Visit patients had a preeclampsia diagnosis (p = 0.02, N = 10 Virtual Visit patients), no other differences were observed between the groups in pregnancy/birth outcomes or health system use. CLINICAL IMPLICATIONS: The Virtual Visit program provides low-risk pregnant women with a new model of prenatal care that does not appear to demonstrate increased risk for mother or baby compared to a traditional model. This program may be especially appealing to middle-/high-income mothers who are partnered and already have children.

Small molecule tyrosine kinase inhibitors of ErbB2/HER2/Neu in the treatment of aggressive breast cancer.

The human epidermal growth factor receptor 2 (HER2) is a member of the erbB class of tyrosine kinase receptors. These proteins are normally expressed at the surface of healthy cells and play critical roles in the signal transduction cascade in a myriad of biochemical pathways responsible for cell growth and differentiation. However, it is widely known that amplification and subsequent overexpression of the HER2 encoding oncogene results in unregulated cell proliferation in an aggressive form of breast cancer known as HER2-positive breast cancer. Existing therapies such as trastuzumab (Herceptin®) and lapatinib (Tyverb/Tykerb®), a monoclonal antibody inhibitor and a dual EGFR/HER2 kinase inhibitor, respectively, are currently used in the treatment of HER2-positive cancers, although issues with high recurrence and acquired resistance still remain. Small molecule tyrosine kinase inhibitors provide attractive therapeutic targets, as they are able to block cell signaling associated with many of the proposed mechanisms for HER2 resistance. In this regard we aim to present a review on the available HER2 tyrosine kinase inhibitors, as well as those currently in development. The use of tyrosine kinase inhibitors as sequential or combinatorial therapeutic strategies with other HER family inhibitors is also discussed.

Modification and biological evaluation of thiazole derivatives as novel inhibitors of metastatic cancer cell migration and invasion.

Fascin has recently emerged as a potential therapeutic target, as its expression in cancer cells is closely associated with tumor progression and metastasis. Following the initial discovery of a series of thiazole derivatives that demonstrated potent antimigration and antiinvasion activities via possible inhibition of fascin function, we report here the design and synthesis of 63 new thiazole derivatives by further structural modifications in search of more potent fascin inhibitors. The 5 series of analogues with longer alkyl chain substitutions on the thiazole nitrogen exhibited greater antimigration activities than those with other structural motifs. The most potent analogue, 5p, inhibited 50% of cell migration at 24 nM. Moreover, the thiazole analogues showed strong antiangiogenesis activity, blocking new blood vessel formation in a chicken embryo membrane assay. Finally, a functional study was conducted to investigate the mechanism of action via interaction with the F-actin bundling protein fascin.

Connexin50D47A decreases levels of fiber cell connexins and impairs lens fiber cell differentiation.

PURPOSE: Substitutions of aspartate-47 (D47) of Connexin50 (Cx50) have been linked to autosomal dominant congenital cataracts in several human pedigrees. To elucidate the lens abnormalities caused by a substitution at this position, we studied No2 mice, which carry the Cx50D47A mutation and parallel the human pathology. METHODS: Lenses from mice of different ages (neonatal to 4 months) were examined by dark-field and immunofluorescence microscopy. Protein levels were determined by immunoblotting using primary antibodies directed against connexins, other membrane proteins, crystallins, and proteins residing in different organelles. RESULTS: Lenses of both heterozygous and homozygous Cx50D47A mice had cataracts and were smaller than those of wild-type littermates. Levels of Cx50 were severely reduced in mutant animals as compared with those in wild-type mice (<20% in heterozygotes and ≤3% in homozygotes). Levels of Cx46 and aquaporin0 were also decreased, but to a lesser extent. The immunostaining pattern of lens connexins was altered in mutant animals. The lenses of Cx50D47A mice showed persistence of nuclear remnants in deep regions of the lens and elevated levels of H3 histone and the mitochondrial protein, Tom20. γ-Crystallin levels were decreased in lenses of all mutant mice, and ß-crystallins were reduced in homozygotes. CONCLUSIONS: These data suggest that mice expressing Cx50D47A develop cataracts due to a severe decrease in the abundance of functional connexin channels. They also implicate Cx50 in fiber cell differentiation, since mutant lenses showed impaired degradation of organelles and decreased levels of some crystallins.

Effects of age on noninvasive assessments of vascular function in nonhuman primates: implications for translational drug discovery.

BACKGROUND: Endothelium-dependent flow mediated dilation (FMD) and pulse-wave velocity (PWV), are used as measures of vascular health and predictors of cardiovascular risk in clinical studies, and both are age-dependent. Numbers of circulating endothelial microparticles (EMPs) and endothelial progenitor cells (EPCs) are also associated with cardiovascular risk, but independent of age in humans. The use of these measurements for pre-clinical assessment of drug cardiovascular safety and efficacy in non-human primates (NHPs) may promote the translation of drug-induced effects on vascular function to clinic outcomes. However, in NHPs, the age effects on the non-invasive measurements of FMD and PWV and the relationship of EMPs/EPCs with FMD are unknown. METHODS: A non-invasive, clinically-relevant approach to assess FMD and PWV was used to examine their relationship with age and with EMPs/EPCs in NHPs. The effects on FMD of nicotine and rosiglitazone were evaluated in senescent primates in an effort to validate our FMD method for pre-clinical assessment of vascular function. RESULTS: FMD and PWV methods were established in a colony (n = 25) of metabolically healthy, cynomolgus monkeys ranging in age from 6 to 26 years. FMD, defined as the percent change, at 1 min of cuff release, from baseline vascular diameter (0.15 ± 0.03 cm), had a strong, negative correlation with age (r = -0.892, p < 0.0001), ranging from 6% to 33%. PWV positively correlated with age (r = 0.622, p < 0.002) in the same healthy monkeys. Nicotine and rosiglitazone, were evaluated in subsets of senescent primates (mean age 16.3 ± 1.5[SEM] years). Rosiglitazone significantly improved FMD (21.0 ± 1.6% vs. vehicle 16.3 ± 1.6%, p < 0.01) without changing baseline diameters, and coincided with a significant increase in circulating numbers of endothelial progenitor cells (CD45-CD31 + CD34 + VEGFR2+ 7.1 ± 1.3 vs. 4.8 ± 1.1 counts/µl) and a decrease in endothelial microparticles (CD45-CD42a-CD54+ 26.7 ± 11.1 vs. 62.2 ± 9.8 counts/µl)(p < 0.05). Conversely, FMD was significantly reduced with nicotine (8.7 ± 1.4% vs. vehicle 20.1 ± 2.2%, p < 0.05). CONCLUSIONS: Adult NHPs demonstrate the characteristic linear relationship between age and vascular function using the non-invasive clinically-related measurements of FMD and PWV. However, numbers of circulating EMPs and EPCs did not correlate with age. Endothelial function assessed with FMD, together with EMPs/EPCs assessment, may serve as a novel approach for translational research and therapeutic discovery. Age should be considered in the study design or data analyses when FMD or PWV is used in NHPs.

A nonpeptide, piperidine renin inhibitor provides renal and cardiac protection in double-transgenic mice expressing human renin and angiotensinogen genes.

INTRODUCTION: Controlling hypertension by angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB), mechanisms that inhibit later pathway steps in the renin-angiotensin system (RAS), have clinically afforded protection against cardiac and renal disease. MATERIALS AND METHODS: In order to determine if blocking the RAS rate-limiting step of angiotensin II generation via renin inhibition could afford similar end organ protection in a human-relevant preclinical model, this study investigated the cardiac and renal effects of a nonpeptide, piperidine renin inhibitor (RI; 100 mg/kg/day PO) in double transgenic mice (dTGM) which express both human renin and angiotensinogen genes. RI was compared to the ARB, candesartan (3 mg/kg/day PO), and to the ACEI, enalapril (60 mg/kg/day PO) in a 4-week dosing paradigm. These doses of RI, ACEI and ARB were previously found to normalize mean blood pressure (MBP) to 110 + 3, 109 + 7 and 107 + 6 mmHg, respectively, after 1 day of treatment. RESULTS AND DISCUSSION: In the dTGM, PRA, plasma aldosterone, GFR, microalbuminuria and left ventricular free wall thickness (LVH) were higher than in the wild type C57BL/6 mice. Microalbuminuria and LVH were significantly reduced by 93% and 9% for the RI, 83% and 13% for enalapril and 73% and 6% for candesartan, respectively. PRA and aldosterone were reduced by the RI 56% and 23%, respectively. These results suggest that the RI provides protection against cardiac and renal disease, similar to ARB and ACEI.