Hypertrophic cardiomyopathy (HCM) is an inherited disease of heart muscle that can be caused by mutations in sarcomere proteins. Clinical diagnosis depends on an abnormal thickening of the heart, but the earliest signs of disease are hyperdynamic contraction and impaired relaxation. Whereas some in vitro studies of power generation by mutant and wild-type sarcomere proteins are consistent with mutant sarcomeres exhibiting enhanced contractile power, others are not. We identified a small molecule, MYK-461, that reduces contractility by decreasing the adenosine triphosphatase activity of the cardiac myosin heavy chain. Here we demonstrate that early, chronic administration of MYK-461 suppresses the development of ventricular hypertrophy, cardiomyocyte disarray, and myocardial fibrosis and attenuates hypertrophic and profibrotic gene expression in mice harboring heterozygous human mutations in the myosin heavy chain. These data indicate that hyperdynamic contraction is essential for HCM pathobiology and that inhibitors of sarcomere contraction may be a valuable therapeutic approach for HCM.

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Alteration in the mechanical properties of arteries occurs with aging and disease, and arterial stiffening is a key risk factor for subsequent cardiovascular events. Arterial stiffening is associated with the loss of functional elastic fibers and increased collagen content in the wall of large arteries. Arterial mechanical properties are controlled largely by the turnover and reorganization of key structural proteins and cells, a process termed growth and remodeling. Fibulin-5 (fbln5) is a microfibrillar protein that binds tropoelastin, interacts with integrins, and localizes to elastin fibers; tropoelastin and microfibrillar proteins constitute functional elastic fibers. We performed biaxial mechanical testing and confocal imaging of common carotid arteries (CCAs) from fibulin-5 null mice (fbln5 −/− ) and littermate controls (fbln5 +/+ ) to characterize the mechanical behavior and microstructural content of these arteries; mechanical testing data were fit to a fourfiber family constitutive model. We found that CCAs from fbln5 −/− mice exhibited lower in vivo axial stretch and lower in vivo stresses while maintaining a similar compliance over physiological pressures compared to littermate controls. Specifically, for fbln5 −/− the axial stretch λ = 1.41 ± 0.07, the circumferential stress σ θ = 101 ± 32 kPa, and the axial stress σ z = 74 ± 28 kPa; for fbln5 +/+ λ = 1.64 ± 0.03, σ θ = 194 ± 38 kPa, and σ z = 159 ± 29 kPa. Structurally, CCAs from fbln5 −/− mice lack distinct functional elastic fibers defined by the lamellar structure of alternating layers of smooth muscle cells and elastin sheets. These data suggest that structural differences in fbln5 −/− arteries correlate with significant differences in mechanical properties. Despite these significant differences fbln5 −/− CCAs exhibited nearly normal levels of cyclic strain over the cardiac cycle.

Four newly synthesized ether lipid esters of cidofovir (CDV), hexadecyloxypropyl-CDV (HDP-CDV), octadecyloxyethyl-CDV (ODE-CDV), oleyloxypropyl-CDV (OLP-CDV), and oleyloxyethyl-CDV (OLE-CDV), were found to have enhanced activities against vaccinia virus (VV) and cowpox virus (CV) in vitro compared to those of CDV. The compounds were administered orally and were evaluated for their efficacies against lethal CV or VV infections in mice. HDP-CDV, ODE-CDV, and OLE-CDV were effective at preventing mortality from CV infection when treatments were initiated 24 h after viral inoculation, but only HDP-CDV and ODE-CDV maintained efficacy when treatments were initiated as late as 72 h postinfection. Oral pretreatment with HDP-CDV and ODE-CDV were also effective when they were given 5, 3, or 1 day prior to inoculation with CV, even when each compound was administered as a single dose. Both HDP-CDV and ODE-CDV were also effective against VV infections when they were administered orally 24 or 48 h after infection. In animals treated with HDP-CDV or ODE-CDV, the titers of both CV and VV in the liver, spleen, and kidney were reduced 3 to 7 log 10 . In contrast, virus replication in the lungs was not significantly reduced. These data indicate that HDP-CDV or ODE-CDV given orally is as effective as CDV given parenterally for the treatment of experimental CV and VV infections and suggest that these compounds may be useful for the treatment of orthopoxvirus infections in humans.Orthopoxvirus diseases continue to pose challenges to researchers preparing for a bioterrorist release of biological weapons of mass destruction. Rapid diagnostics for smallpox and the development of effective antiviral chemotherapies are two essential components for national preparedness (16,17). The in vitro and in vivo activities of cidofovir (CDV) against orthopoxviruses are well documented (3,4,8,9,15,18,(20)(21)(22)(23)(24); however, its usefulness is limited by the requirement for intravenous administration and dose-limiting nephrotoxicity (14). Orally active compounds with prolonged therapeutic levels in blood and reduced toxicity would be desirable for mass distribution in response to an actual release of the smallpox virus.Results from earlier studies with acyclovir and ganciclovir showed that alkoxyalkyl esters of the monophosphates of ganciclovir or acyclovir have improved oral bioavailabilities compared to those of the unmodified parent compounds and are effective against cytomegalovirus and herpes simplex virus infections (13). To improve the oral bioavailability of CDV, a novel series of analogs were synthesized by esterification with long-chain alkoxyalkanols. Hexadecyloxypropyl-CDV (HDP-CDV) and octadecyloxyethyl-CDV (ODE-CDV) were synthesized and evaluated in vitro for their efficacies against cowpox virus (CV) and vaccinia virus (VV) infections. As reported previously (15), HDP-CDV had 50% effective concentrations (EC 50 s) of 0.52 and 0.62 M against CV and VV, respectively, whereas the EC 50 s of CDV were 42 and 31 M, respectively. ODE-CD...

Cidofovir (CDV) is an effective therapy for certain human cytomegalovirus (HCMV) infections in immuno-compromised patients that are resistant to other antiviral drugs, but the compound is not active orally. To improve oral bioavailability, a series of lipid analogs of CDV and cyclic CDV (cCDV), including hexadecyloxypropyl-CDV and -cCDV and octadecyloxyethyl-CDV and -cCDV, were synthesized and found to have multiple-log-unit enhanced activity against HCMV in vitro. On the basis of the activity observed with these analogs, additional lipid esters were synthesized and evaluated for their activity against herpes simplex virus (HSV) types 1 and 2, human cytomegalovirus, murine cytomegalovirus, varicella-zoster virus (VZV), EpsteinBarr virus (EBV), human herpesvirus 6 (HHV-6), and HHV-8. Using several different in vitro assays, concentrations of drug as low as 0.001 M reduced herpesvirus replication by 50% (EC 50 ) with the CDV analogs, whereas the cCDV compounds were generally less active. In most of the assays performed, the EC 50 values of the lipid esters were at least 100-fold lower than the EC 50 values for unmodified CDV or cCDV. The lipid analogs were also active against isolates that were resistant to CDV, ganciclovir, or foscarnet. These results indicate that the lipid ester analogs are considerably more active than CDV itself against HSV, VZV, CMV, EBV, HHV-6, and HHV-8 in vitro, suggesting that they may have potential for the treatment of infections caused by a variety of herpesviruses.

The acyclic nucleoside phosphonate cidofovir (CDV) and its closely related analogue (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)-adenine ([S]-HPMPA) have been reported to have activity against many adenovirus (AdV) serotypes. A new series of orally active ether lipid-ester prodrugs of CDV and of (S)-HPMPA that have slight differences in the structure of their lipid esters were evaluated, in tissue-culture cells, for activity against 5 AdV serotypes. The results indicated that, against several AdV serotypes, the most active compounds were 15-2500-fold more active than the unmodified parent compounds and should be evaluated further for their potential to treat AdV infections in humans.

9-(S)-(3-Hydroxy-2-phosphonomethoxypropyl)adenine [(S)-HPMPA] was one of the first acyclic nucleoside phosphonates described and has been reported to have good antiviral activity against most double-stranded DNA viruses, including the herpes group viruses and the orthopoxviruses. However, (S)-HPMPA is not orally bioavailable and has not been developed for clinical use. We have prepared orally bioavailable lipid esters of (S)-HPMPA and report their synthesis and antiviral evaluation against cytomegalovirus and orthopoxviruses. These esters were evaluated in vitro in cells infected with human cytomegalovirus (HCMV), murine cytomegalovirus (MCMV), vaccinia (VV), and cowpox viruses (CV). The most active compound, oleyloxyethyl-(S)-HPMPA, was found to have EC50 value of 0.003 microM against HCMV vs 1.4 microM for unmodified HPMPA. In cells infected with VV and CV, octadecyloxyethyl-(S)-HPMPA had EC50 values of 0.01-0.02 microM versus 2.7-4.0 microM for unmodified HPMPA. When compared with the alkoxyalkyl esters of cidofovir, the corresponding alkoxyalkyl esters of (S)-HPMPA were equally active against HCMV and MCMV but were 15-20-fold more active against VV and CV in vitro. The alkoxyalkyl esters of (S)-HPMPA are promising new compounds worthy of further investigation for treatment of infections caused by herpes viruses and orthopoxviruses.

Alkoxyalkyl esters of cidofovir (CDV) have substantially greater antiviral activity and selectivity than unmodified CDV against herpesviruses and orthopoxviruses in vitro. Enhancement of antiviral activity was also noted when cyclic CDV was esterified with alkoxyalkanols. In vitro antiviral activity of the most active analogs against human cytomegalovirus (HCMV) and orthopoxviruses was increased relative to CDV up to 1,000-or 200-fold, respectively. Alkyl chain length and linker structure are important potential modifiers of antiviral activity and selectivity. In this study, we synthesized a series of alkoxyalkyl esters of CDV or cyclic CDV with alkyl chains from 8 to 24 atoms and having linker moieties of glycerol, propanediol, and ethanediol. We also synthesized alkyl esters of CDV which lack the linker to determine if the alkoxyalkyl linker moiety is required for activity. The new compounds were evaluated in vitro against HCMV and murine CMV (MCMV). CDV or cyclic CDV analogs both with and without linker moieties were highly active against HCMV and MCMV, and their activities were strongly dependent on chain length. The most active compounds had 20 atoms esterified to the phosphonate of CDV. Both alkoxypropyl and alkyl esters of CDV provided enhanced antiviral activities against CMV in vitro. Thus, the oxypropyl linker moiety is not required for enhanced activity. CDV analogs having alkyl ethers linked to glycerol or ethanediol linker groups also demonstrated increased activity against CMV.Cidofovir (CDV), an acyclic phosphonate analog of dCMP, is an antiviral agent that is active against all double-stranded DNA viruses including herpes simplex, cytomegalovirus (CMV), orthopoxviruses, adenovirus, Epstein-Barr virus, polyomavirus, and papillomavirus (9). CDV is not orally active but is effective when administered intravenously for CMV retinitis in patients with AIDS (8,19). Esterification of CDV with certain alkoxyalkanols dramatically increases the antiviral activity and selectivity of CDV in vitro (2, 11, 13, 15) and confers oral bioavailability (4,5,6,14,20). Hexadecyloxypropyl-CDV (HDP-CDV) and various other alkoxyalkyl CDV esters are orally active in three lethal challenge models of poxvirus disease (5, 20) and in animal models of CMV disease (4, 14).The alkyl chain length of these CDV analogs is related to solubility and the ability of the compounds to associate with biomembranes. To examine the effect of structure on antiviral activity and selectivity of alkoxyalkanol-CDV analogs against CMV, we synthesized a family of alkoxypropylCDVs and -cyclic CDVs (cCDVs) varying in overall chain length from 8 to 24 atoms. The nature of the linker group is also important because it may strongly affect the rate of cellular metabolic conversion to CDV. We synthesized several representative analogs having propanediol, ethandiol, or glycerol linkers to assess the effect of the linker structure. Finally, we also synthesized and evaluated a series of alkylCDVs lacking the linker.The various CDV and cCDV analogs were tested...