Entity

Time filter

Source Type

HAMDEN, CT, United States

Halley P.,University of Miami | Kadakkuzha B.,University of Miami | Faghihi M.,University of Miami | Magistri M.,University of Miami | And 6 more authors.
Cell Reports | Year: 2014

Apolipoprotein A1 (APOA1) is the major protein component of high-density lipoprotein (HDL) in plasma. We have identified an endogenously expressed long noncoding natural antisense transcript, APOA1-AS, which acts as a negative transcriptional regulator of APOA1 both invitro and invivo. Inhibition of APOA1-AS in cultured cells resulted in the increased expression of APOA1 and two neighboring genes in the APO cluster. Chromatin immunoprecipitation (ChIP) analyses of a ~50 kb chromatin region flanking the APOA1 gene demonstrated that APOA1-AS can modulate distinct histone methylation patterns that mark active and/or inactive gene expression through the recruitment of histone-modifying enzymes. Targeting APOA1-AS with short antisense oligonucleotides also enhanced APOA1 expression in both human and monkey liver cells and induced an increase in hepatic RNA and protein expression in African green monkeys. Furthermore, the results presented here highlight the significant local modulatory effects of long noncoding antisense RNAs and demonstrate the therapeutic potential of manipulating the expression of these transcripts both invitro and invivo. © 2014 The Authors. Source


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 203.04K | Year: 2013

Optic nerve and retinal diseases profoundly impact quality of life and overall health care burden. Demetrios Vavvas and colleagues at the Mass Eye and Ear Infirmary (MEEI) have revealed a critical redundant role of mediators of both apoptosis and necrosisin cell death in the neuroretina and optic nerve in multiple ophthalmic disease models, supporting their importance as possible drug targets. Most notably, blockade of RIP kinase 1, a regulator of necrosis, pharmacologically or by gene knockout, acts synergistically with the arrest of apoptosis by pan-caspase inhibition to achieve remarkable preservation of neuronal viability and function. Specifically, when treated with pan-caspase inhibitors, Rip3-/- mice, lacking activated RIP kinase 1, are highly resistant to photoreceptor cell loss in the setting of models of retinal detachment, retinitis pigmentosa and age related macular degeneration (AMD), and retinal ganglion cells (RGCs) loss in disease models specifically impacting inner retinal and optic nerve function. This synergistic protective effect has additionally been demonstrated in wild type mice co-dosed with RIP kinase 1 and pan-caspase inhibitors. Despite the promise of applying this newly defined dual pathway inhibition to prevalent conditions such as AMD and glaucoma, the challenges of sustained therapeutic delivery to the back of the eye, and the design of clinical trials for slowly progressing neurodegenerative diseases favors pursuit of early clinical applications to conditions with rapid onset secondary to acute, minimally progressing pathology with anticipated short treatment periods, and clear efficacy endpoints and subject recruitment criteria. One such condition is non-arteritic ischemic optic neuropathy (NAION), the most common cause of acuteoptic nerve related vision loss, for which there are limited therapeutic options. After an initial focal ischemia associated with reduced perfusion of the microvasculature of the optic disc, often in the setting of an anatomically susceptible disc and/orsystemic hypotension, a cascade of events contributes to axonal injury and RCG endangerment, culminating in caspace-associated apoptosis. There is additional abundant corollary evidence to suggest a critical roll of RIP kinase as an ultimate contributor toRGC fate via the necrotic pathway. Vavvas et al. have demonstrated rescue of RGCs in rodents by the synergistic RIP kinase 1/pan-caspase inhibition in the setting of traumatic optic neuropathy and NMDA-associated excitotoxicity. They have further established a laser photoembolic model of NAION in the rodent, employing mesoporphyrin as a fluorophore to achieve focal microvessel disruption at the disc by targeted laser photoexcitation. In this proposal, we will characterize the mesopophyrin model in the nonhuman primate and apply robustly defined clinically relevant endpoints to evaluate the efficacy of intravitreal (IVT) co-injection of the inhibitor Nec-1 and IDN-6556, both of which have been demonstrated to be potent inhibitors of RIP kinase 1 and caspases, respectively, and to be well tolerated and bioavailable following IVT injection, with combined clinical application encompassed by MEEI intellectual property that we are partnering to advance. PUBLIC HEALTH RELEVANCE PUBLIC HEALTH RELEVANCE: Two different molecular pathways contribute to cell death - apoptosis, critically mediated by caspases, and necrosis, which more recently has been demonstrated to be critically mediated by RIP kinases. Members of our team have demonstrated that combined inhibitionof caspases and RIP kinase 1 achieves dramatic neuroprotection in multiple ophthalmic disease models in rodents. We will establish a neuroprotection model in the nonhuman primate that closely mimics non-arteritic ischemic optic neuropathy (NAION; the mostcommon cause of acute vision loss related to the optic nerve), and will apply this model to translational studies to develop a combined drug product for NAION, for which there are limited existing therapeutic options.


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 227.76K | Year: 2004

DESCRIPTION (provided by applicant): Parkinson's disease is a prevalent and devastating neurodegenerative condition of unknown etiology. One prominent hypothesis holds that the selective loss of the nigrostriatal dopaminergic neurons characteristic of th


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 718.30K | Year: 2011

DESCRIPTION (provided by applicant): Heart disease remains the primary cause of morbidity and mortality in the industrialized world and continues to incur costs estimated at 30 billion per year, despite detailed understanding of the mechanisms governing cardiac function and contractility. MicroRNAs (miRNAs), a recently discovered family of tiny regulatory RNAs, act as negative regulators of gene expression by inhibiting the translation or promoting the degradation of target mRNAs. Because individual miRNAsoften regulate the expression of multiple target genes with related functions, modulating the expression of a single microRNA can, in principle, influence an entire gene network and thereby modify complex disease phenotypes. Recent demonstration of novelroles for miRNAs in the control of diverse aspects of cardiac function and dysfunction provides a wholly new aspect of disease biology to target for therapeutic intervention. Studies by our collaborative group and others have revealed roles for miRNAs in the control of myocyte growth, integrity of the ventricular wall, contractility, maintenance of cardiac rhythm, apoptosis and fibrosis. In particular, our collaborators at miRagen have examined miR-208, a cardiac-specific miRNA that is co-expressed with 1-myosin heavy chain (1MHC). Mice homozygous for the miR-208 deletion are viable and do not display obvious abnormalities in size, shape, or structure of the heart but, significantly, appear resistant to cardiac stress, as shown by a lack of hypertrophy and fibrosis following thoracic aortic banding (TAB). Follow up studies have shown that systemic administration of a locked-nucleic acid (LNA)-modified oligonucleotide (antimiR) binding the mature miR-208 sequence results in significant decreases in cardiac levels of miR-208a. In concordance with the miR-208 knockout mice, antimiR-208 treatment in a rat model for heart failure preserves cardiac function, reduces cardiac remodeling, and increases survival. Where rodent hearts express more 1MHC, monkey hearts, like human hearts, predominantly express 2M HC. Both myosins co-express a miRNA-208 isoform that we will designate as miR- 208a (coming from 1MHC) and miR-208b (coming from 2MHC). Although it is unclear whether miR-208a and miR-208b have overlapping functions, preliminary data in African green monkeys indicate that both isoforms of miR-208 can be specifically targeted in a monkey heart and inducesmiR-208 inhibition lasting for at least 1 month. The current proposal focuses on evaluating the biodistribution, pharmacokinetics and pharmacokinetic/ pharmacodynamics (PK/PD) of antimiR-208a vs. antimiR-208b following systemic delivery in monkeys. Additionally we will induce chronic hypertension to define microRNA changes associated with cardiac remodeling and dysfunction in the setting of congestive heart failure (CHF). Characterization of the pathophysiology will include determination of cardiac tissue expression of miR-208 isoforms, myosin expression, cardiac remodeling and extensive evaluation of functional deficit post-occlusion. Demonstrating hypertrophy and fibrosis in the miR-208 expressing myocardium, coupled with PK/PD data, will permit compelling efficacy assessments in phase II to enable rapid advancement of a miR-208-specific antimiR into IND-enabling toxicology studies and clinical trials. PUBLIC HEALTH RELEVANCE: MicroRNAs, tiny regulators of gene expression and degradation, can regulate cardiac response to injury and our collaborators have demonstrated that cardiac levels of one of these microRNAs, miR-208, is upregulated during cardiac injury and that specific knock down of this with a modified oligonucleotide sequence (antimiR) administered to the bloodstream reduces injury in rodent models of heart failure. We have demonstrated similar knockdown of miR-208 in monkeys by similar antimiR delivery and here propose to determine the pharmacokinetics, pharmacodynamics and biodistribution of antimiRs designed to knock down miR-208 in monkeys to determine optimal dosing. In addition, we will comprehensively characterize miR-208-relevant pathophysiology in a monkey model of congestive heart failure to allow critical pre-clinical efficacy studies to be completed in phase II.


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 208.55K | Year: 2006

DESCRIPTION (provided by applicant): The blood-brain barrier (BBB) represents both a safeguard against the penetration of physiologically harmful substances into the central nervous system (CMS), and a considerable hurdle to the delivery of therapeutic agents. A technology allowing safe, targeted, reversible opening of the BBB would potentially revolutionize both the study and treatment of CNS disorders, including neurodegenerative conditions and brain and spinal cord malignancies that have proven resistant to conventional approaches. BBB disruption with hypertonic solutions enhances CNS penetration of macromolecules, but at the cost of pronounced fluid shifts and lack of regional specificity. Ultrasound-mediated BBB disruption has been another approach explored. High intensity focused ultrasound (HIFU) has been demonstrated to open the BBB at energy levels that do not result in cellular injury, but associated heating of bone and adjacent tissue prevents HIFU application without direct exposure of the brain by the creation of a bone window. A further drawback is the long duration of opening induced. More recently, low intensity directed ultrasound (LODUS) has been demonstrated to have a similar effect on the barrier properties of the cerebral microvasculature without the confounds of HIFU. Incidental discovery of the permeabilizing effect occurred when non-invasive transcranial application of LODUS to a human patient was found to result in enhanced extravasation of MRI contrast material without evidence of injury. Subsequent rodent studies demonstrated that even under non- optimized conditions LODUS induced a safe and rapidly reversible opening of the BBB to substances as large as adenovirus vectors. The goal of this Phase I study will be to conduct dose response experiments addressing the important ultrasound delivery parameters of intensity and pulse length in a preclinical validation of safety and efficacy in African green monkeys. The proposed experiments would not be possible in non-primate animal models for important anatomic considerations or in humans for cost and ethical reasons. Evans Blue, which binds serum albumin, will be employed as a marker of macromolecule BBB permeability to allow both a visual and quantitative determination of efficacy through well established fluorometric techniques. Successful completion of these primate optimization studies will allow development of robust and clinically relevant protocols for the reversible opening of the BBB for research and therapeutic applications to neurodegenerative diseases, brain cancer and other CNS conditions. Blood vessels in the brain differ from those in the rest of the body in that they prevent most drugs from passing into the surrounding tissue. While this is often beneficial, it can inhibit the range of therapies that can be employed to successfully treat diseases such as Alzheimer's and brain cancer. This research aims to develop a method to deliver drugs and other therapies to the brain in a way that is safe and easy to apply.

Discover hidden collaborations