Project description:Spinal pain and associated disability is a leading cause of morbidity worldwide that has a strong association with degenerative disc disease (DDD). DDD can begin in early-late adolescence and has a variable course. Biologically based therapies to treat DDD face significant challenges posed by the unique milieu of the environment within the intervertebral discs. Many potential promising therapies are still in the early stages of development with a hostile microenvironment within the disc presenting unique challenges. The translational potential of this article: Patient selection, reasonable therapeutic goals, approach, and timing will need to be discerned in order to successfully translate potential therapeutics.
Project description:Retinal gene therapy has advanced considerably in the past three decades. Initial efforts have been devoted to comprehensively explore and optimize the transduction abilities of gene delivery vectors, define the appropriate intraocular administration routes and obtain evidence of efficacy in animal models of inherited retinal diseases (IRDs). Successful translation in clinical trials of the initial promising proof-of-concept studies led to the important milestone of the first approved product for retinal gene therapy in both US and Europe. The unprecedented clinical development observed during the last decade in the field is however highlighting new challenges that will need to be overcome to bring gene therapy to fruition to a larger patient population within and beyond the realm of IRDs.
Project description:Preclinical mechanistic studies have pointed towards RNAi-mediated off-target effects as a major driver of hepatotoxicity for GalNAc-siRNA conjugates. Here we demonstrate that a single glycol nucleic acid (GNA) modification can substantially reduce siRNA seed-mediated binding to off-target transcripts while maintaining on-target activity. In siRNAs with established off-target effects leading to hepatotoxicity, these Enhanced Stabilization Chemistry plus (ESC+) designs exhibit a substantially improved therapeutic window in rat. We utilized this strategy to improve the safety of ALN-HBV, which exhibited dose-dependent, transient, and asymptomatic alanine aminotransferase elevations in healthy volunteers.
Project description:Genome sequencing has revolutionized the diagnosis of genetic diseases. Close collaborations between basic scientists and clinical genomicists are now needed to link genetic variants with disease causation. To facilitate such collaborations, we recommend prioritizing clinically relevant genes for functional studies, developing reference variant-phenotype databases, adopting phenotype description standards, and promoting data sharing.
Project description:Fragile X syndrome (FXS), an inherited intellectual disability often associated with autism, is caused by the loss of expression of the fragile X mental retardation protein. Tremendous progress in basic, preclinical, and translational clinical research has elucidated a variety of molecular-, cellular-, and system-level defects in FXS. This has led to the development of several promising therapeutic strategies, some of which have been tested in larger-scale controlled clinical trials. Here, we will summarize recent advances in understanding molecular functions of fragile X mental retardation protein beyond the well-known role as an mRNA-binding protein, and will describe current developments and emerging limitations in the use of the FXS mouse model as a preclinical tool to identify therapeutic targets. We will review the results of recent clinical trials conducted in FXS that were based on some of the preclinical findings, and discuss how the observed outcomes and obstacles will inform future therapy development in FXS and other autism spectrum disorders.
Project description:From the bedside of patients contributing samples to large genome-wide association studies for atrial fibrillation (AF), over 100 AF risk loci have been identified. The top locus is near a gene implicated in pulmonary vein formation; the ostia of the pulmonary veins harbor initiating triggers of AF, and isolation of these areas is the cornerstone of ablation therapies for AF. Transcriptomic studies suggest that AF is associated with impaired or overwhelmed responses to cell stress. A dual risk model proposes that in genetically-susceptible individuals, inadequate transcriptional responses to stress predispose to AF in later life. Drugs targeting metabolic, oxidative, or protein handling stress may be novel upstream agents to bring back to the bedside for study in the prevention of AF.
Project description:Dexmedetomidine Diminishes Halothane Anesthetic Requirements in Rats Through a Postsynaptic Alpha 2 Adrenergic Receptor. By Segal IS, Vickery RG, Walton JK, Doze VA, and Maze M. ANESTHESIOLOGY 1988; 125:590-4. Abstract reprinted with permission.The effect of 4(5)-[1-(2,3-dimethylphenyl)ethyl]imidazole (medetomidine), the ?2 adrenergic agonist, on anesthetic requirements was investigated in rats anesthetized with halothane. Halothane MAC was determined before and after either dexmedetomidine (D-enantiomer) or levomedetomidine (L-enantiomer) 10, 30, and 100 ?g/kg, or vehicle intraperitoneally. There was a dose-dependent increase in MAC with the D-, but not the L-, stereoisomer. At the highest dose of dexmedetomidine (100 ?g/kg), halothane could be discontinued for up to 30?min with no response to tail clamping. To determine whether ?2 adrenoreceptors mediated this effect of dexmedetomidine on MAC, cohorts of rats were pretreated with idazoxan, 10?mg/kg intraperitoneally, a highly selective ?2 antagonist. This completely prevented the reduction of MAC caused by dexmedetomidine. To determine whether the reduction of MAC caused by dexmedetomidine was mediated in part through either opiate or adenosine receptors, groups of rats were pretreated with either naltrexone, 5?mg/kg intraperitoneally, an opiate antagonist, or 8-phenyltheophylline, 2.5?mg/kg intraperitoneally, an A1 adenosine antagonist. These two pretreatments did not alter the reduction of MAC by dexmedetomidine. To determine whether postsynaptic mechanisms mediate the anesthetic effect of dexmedetomidine, rats were depleted of central catecholamine stores with either n-(2-chloroethyl)-n-ethyl-2-bromobenzylamine or reserpine and ?-methyl-para-tyrosine, and MAC was determined before and after each dose of dexmedetomidine. While the catecholamine-depleted rats had a lower basal MAC than the vehicle controls, there was still a profound reduction in halothane MAC after administration of dexmedetomidine. The reduction of MAC by dexmedetomidine was blocked with idazoxan in the catecholamine-depleted rats. These data indicate that the reduction of MAC caused by dexmedetomidine is mediated through ?2 adrenoreceptors with no apparent involvement of either opiate or A1 adenosine receptors. Data from catecholamine-depleted rats suggest that the mediating mechanism must involve site(s) other than or in addition to the presynaptic ?2 adrenergic receptors on noradrenergic neurons. The authors conclude that central postsynaptic ?2 adrenergic receptors mediate a significant part of the reduction of anesthetic requirements caused by dexmedetomidine.
Project description:BACKGROUND:Alpha-1-antitrypsin (AAT) deficiency (AATD) of Z, Mmalton, Siiyama type is associated with liver storage of the mutant proteins and liver disease. The Z variant can be diagnosed on isoelectric focusing (IEF) while Mmalton and Siiyama may be missed or misdiagnosed with this technique. Therefore, molecular analysis is mandatory for their characterization. In particular, that holds true for the Mmalton variant as on IEF profile it resembles the wild M2 subtype. METHODS:This is a retrospective analysis involving review of medical records and of liver biopsy specimens from a series of Mmalton, Z and Siiyama Alpha-1-antitrypsin deficiency patients. The review has been implemented by additional histological stains, electron microscopic observations and 3-D modeling studies of the sites of the mutations. RESULTS:Z, Mmalton and Siiyama liver specimen contained characteristic intrahepatocytic PAS-D globules. The globules differed in the three variants as only Mmalton cases showed dark basophilic precipitates within the AAT inclusions. The precipitates were visualized in haematoxylin-eosin (H.E.) stained preparations and corresponded to calcium precipitates as demonstrated by von Kossa staining. On immunohistochemistry, ZAAT inclusions were stained by polyclonal as well as monoclonal noncommercial anti-AAT antibody (AZT11), whilst Mmalton and Siiyama inclusion bodies remained negative with the monoclonal anti-Z antibody. 3-D protein analysis allowed to predict more severe misfolding of the Mmalton molecule as compared to Z and Siiyama that could trigger anomalous interaction with endoplasmic reticulum chaperon proteins, namely calcium binding proteins. CONCLUSIONS:Mmalton AAT inclusion bodies contain calcium precipitates inside them that allow the differential diagnosis with Siiyama and ZAAT inclusions in routine histological sections. The study has confirmed the specificity of the monoclonal AZT11 for the Z mutant. Thus, the combination of these two features is crucial for the distinction between the three variants and for predicting the genotype, whose confirmation would definitely require molecular analysis. Our study provides new data on the pathomorphogenesis of Mmalton inclusion bodies whose mineralization could play a central role in disease pathogenesis of Mmalton that is distinct from the Z and Siiyama variants. Calcium is known to be a major effector of cell death either via the increased intracellular concentration or the alteration of homeostasis.