Antisense oligonucleotides (ASOs) hold promise for gene-specific knockdown in diseases that involve RNA or protein gain-of-function. In the hereditary degenerative disease myotonic dystrophy type 1 (DM1), transcripts from the mutant allele contain an expanded CUG repeat1–3 and are retained in the nucleus4, 5. The mutant RNA exerts a toxic gain-of-function6, making it an appropriate target for therapeutic ASOs. However, despite improvements in ASO chemistry and design, systemic use of ASOs is limited because uptake in many tissues, including skeletal and cardiac muscle, is not sufficient to silence target mRNAs7, 8. Here we show that nuclear-retained transcripts containing expanded CUG (CUGexp) repeats are extraordinarily sensitive to antisense silencing. In a transgenic mouse model of DM1, systemic administration of ASOs caused a rapid knockdown of CUGexp RNA in skeletal muscle, correcting the physiological, histopathologic, and transcriptomic features of the disease. The effect was sustained for up to one year after treatment was discontinued. Systemically administered ASOs were also effective for muscle knockdown of Malat-1, a long noncoding RNA (lncRNA) that is retained in the nucleus9. These results provide a general strategy to correct RNA gain-of-function and modulate the expression of expanded repeats, lncRNAs, and other transcripts with prolonged nuclear residence.

Sepsis is a deadly disease characterized by considerable derangement of the proinflammatory, anti-inflammatory and coagulation responses. Protease-activated receptor 1 (PAR1), an important regulator of endothelial barrier function and blood coagulation, has been proposed to be involved in the lethal sequelae of sepsis, but it is unknown whether activation of PAR1 is beneficial or harmful. Using a cell-penetrating peptide (pepducin) approach, we provide evidence that PAR1 switched from being a vascular-disruptive receptor to a vascular-protective receptor during the progression of sepsis in mice. Unexpectedly, we found that the protective effects of PAR1 required transactivation of PAR2 signaling pathways. Our results suggest therapeutics that selectively activate PAR1-PAR2 complexes may be beneficial in the treatment of sepsis.Sepsis remains the leading cause of mortality of patients in intensive care units, causing at least 210,000 deaths annually in the United States1. Much of the pathology of sepsis has been attributed to a hyper-reaction of the inflammatory system to the invading pathogens, a condition called 'systemic inflammatory response syndrome' 2 . During the early phases of sepsis, systemic concentrations of inflammatory cytokines and chemokines rapidly increase and the endothelium is activated to cause vascular leakage and septic shock. In late-stage sepsis, the clotting cascade is triggered by the damaged endothelium, leading to disseminated intravascular coagulation (DIC) and multiorgan failure 3, 4. The vascular damage is caused by many sepsis-related factors, including bacterial endotoxin, tumor

Abstract-Thrombosis associated with the pathophysiological activation of platelets and vascular cells has brought thrombin and its receptors to the forefront of cardiovascular medicine. Thrombin signaling through the protease-activated receptors (PARs) has been shown to influence a wide range of physiological responses including platelet activation, intimal hyperplasia, inflammation, and maintenance of vascular tone and barrier function. The thrombin receptors PAR1 and PAR4 can be effectively targeted in animals in which acute or prolonged exposure to thrombin leads to thrombosis and/or restenosis. In the present study, we describe the molecular and pharmacological basis of small-molecule inhibitors that target PAR1. In addition, we discuss a new class of cell-penetrating inhibitors, termed pepducins, that provide insight into previously unidentified roles of PAR1 and PAR4 in protease signaling. Key Words: arteries Ⅲ endothelium Ⅲ inhibitors Ⅲ platelets Ⅲ receptors Ⅲ signal transduction Ⅲ thrombosis P rotease-activated receptors (PARs) play critical roles in coagulation, inflammation, and vascular homeostasis. [1][2][3][4][5] Proteases that are produced during vascular injury exert many of their cellular effects by cleaving and activating the PARs. Thrombin-dependent platelet activation and aggregation have been shown to be heightened in the setting of angioplasty and stenting, which may cause clinical complications including acute myocardial infarction and death. 6 -8 The high-affinity thrombin receptor PAR1 has long been recognized as an obvious candidate for therapeutic intervention in patients with acute coronary syndromes. It is not yet known, however, whether targeting only PAR1 will achieve sufficient therapeutic efficacy because of the presence of a more recently identified second thrombin receptor named PAR4. 9 -12 PAR1 and PAR2 (a trypsin but not a thrombin receptor) have also been shown to affect other cardiovascular functions such as vasoreactivity and cardiomyocyte hypertrophy.The purpose of the present review is to help the clinical reader understand why PARs are essential for the maintenance of normal vascular integrity. This review will focus on the potential therapeutic utility of targeting the PARs in thrombosis, atherosclerosis, and restenosis. Historically, the PARs have been recalcitrant to the development of peptidomimetic-based antagonists; however, recent PAR1 drug candidates based on natural products are now entering large-scale clinical trials for treatment of patients with acute coronary syndromes. In an orthogonal approach, PARs have also been blocked on the inside of the cell with the use of cell-penetrating pepducins that prevent signaling to internally located G proteins. [13][14][15][16][17] Proof-of-concept experiments in acute thrombosis models point to novel antiplatelet therapies that could potentially benefit patients at risk for acute thrombosis. The Role of PARs in Normal Platelet FunctionPlatelets are essential for proper blood coagulation. Initiation of a platelet thromb...