Anusch Peyman

PNA: Synthetic Polyamide Nucleic Acids with Unusual Binding Properties

The astonishing discovery that peptide nucleic acids (PNAs, B=nucleobase), in spite of their drastic structural difference to natural DNA, are better nucleic acid mimetics than many other oligonucleotides has resulted in an explosion of research into this class of compounds. The synthesis, physical properties, and biological interactions of PNAs as well as their chimeras with DNA and RNA are summarized here.

Alirocumab inhibits atherosclerosis, improves the plaque morphology, and enhances the effects of a statin

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition is a potential novel strategy for treatment of CVD. Alirocumab is a fully human PCSK9 monoclonal antibody in phase 3 clinical development. We evaluated the antiatherogenic potential of alirocumab in APOE*3Leiden.CETP mice. Mice received a Western-type diet and were treated with alirocumab (3 or 10 mg/kg, weekly subcutaneous dosing) alone and in combination with atorvastatin (3.6 mg/kg/d) for 18 weeks. Alirocumab alone dose-dependently decreased total cholesterol (−37%; −46%, P < 0.001) and TGs (−36%; −39%, P < 0.001) and further decreased cholesterol in combination with atorvastatin (−48%; −58%, P < 0.001). Alirocumab increased hepatic LDL receptor protein levels but did not affect hepatic cholesterol and TG content. Fecal output of bile acids and neutral sterols was not changed. Alirocumab dose-dependently decreased atherosclerotic lesion size (−71%; −88%, P < 0.001) and severity and enhanced these effects when added to atorvastatin (−89%; −98%, P < 0.001). Alirocumab reduced monocyte recruitment and improved the lesion composition by increasing the smooth muscle cell and collagen content and decreasing the macrophage and necrotic core content. Alirocumab dose-dependently decreases plasma lipids and, as a result, atherosclerosis development, and it enhances the beneficial effects of atorvastatin in APOE*3Leiden.CETP mice. In addition, alirocumab improves plaque morphology.

Non-peptide-based inhibitors of human immunodeficiency virus-1 protease

Abstract The use of bis(α-aminoalkyl)phosphinic acids as analogs of the tetrahedral intermediate formed on the path to peptide hydrolysis in combination with a mimic for a structural water, which is found in HIV protease inhibitor complexes, leads to potent inhibitors of HIV-1 protease.

Novel synthetic routes to PNA monomers and PNA-DNA linker molecules

Abstract Novel methods for the preparation of monomethoxytrityl (Mmt) protected aminoethylglycine building blocks and dimethoxytrityl (Dmt) protected hydroxyethylglycine derivatives useful for the synthesis of polyamide nucleic acids (PNAs) and PNA/DNA chimeras are described. The protecting group strategy employed for PNA monomer synthesis produces easily isolable intermediates, minimizes chromatographic purification, and is suitable for large-scale monomer synthesis.

Use of minimally modified antisense oligonucleotides for specific inhibition of gene expression

Abstract The design and use of minimally modified oligonucleotides for specific inhibition of gene expression is discussed. The “minimal” protection strategy is a combination of the end-capping technique and the protection of internal pyrimidine positions which are the major sites of endonuclease degradation. By reducing the number of phosphorothioate modifications needed to make the oligonucleotide resistant to nuclease degradation, non-sequence-specific effects, which are frequently observed with uniformly phosphorothioate-modified oligonucleotides, can be reduced.

PNAs: synthetische Polyamidnucleinsäuren mit außergewöhnlichen Bindungseigenschaften

Auserst uberraschend war die Erkenntnis, das Peptidnucleinsauren (PNAs, B=Nucleobase) trotz ihrer drastisch vom naturlichen DNA-Ruckgrat abweichenden Struktur besser als die meisten Oligonucleotidderivate als Nucleinsauremimetica genutzt werden konnen. Die Synthese, physikalischen Eigenschaften und biologischen Wechselwirkungen sowohl der PNAs als auch ihrer Chimaren mit DNA und RNA werden hier zusammenfassend beschrieben.

Oligodeoxynucleotide Targeted to the αv Gene Inhibits αv Integrin Synthesis, Impairs Osteoclast Function, and Activates Intracellular Signals to Apoptosis

The αv integrin subunit is highly expressed in osteoclasts where it dimerizes with β1 and β3 subunits to form receptors for vitronectin and bone sialoproteins. Inhibition of osteoclast adhesion and function has previously been achieved by αvβ3 antibodies or Arg‐Gly‐Asp–containing peptides which have the disadvantages of blocking a single receptor type, or of being rather nonspecific, respectively. Here we show that αv integrin expression in rabbit osteoclasts can be inhibited by partially phosphorothioated antisense oligodeoxynucleotide (ODN) spanning the adenine‐uracil‐guanine (AUG) translational start site of the human/rabbit αv gene, a procedure which offers the advantage of affecting all the αv receptors with high efficiency. The αv antisense ODN caused a dose‐dependent, substrate‐specific reduction of osteoclast adhesion and bone resorption. Control ODNs, such as sense, inverted, and mismatch, were without effect, providing evidence of specificity of the antisense reagent. It is likely as a consequence of loss of substrate interaction, the antisense ODN induced osteoclast retraction and apoptosis, increase of the cyclin/cyclin‐dependent kinase complex inhibitor p21WAF1/CIP1, and inhibition of the cell survival gene, bcl‐2. Although the expression of the cell death–promoting gene, bax, remained unchanged, a reduction of the bcl‐2/bax ratio, known to underlie the intracellular signal to apoptosis, was observed. This finding led us to hypothesize that these changes could provide a link between reduction of αv synthesis and osteoclast programmed death. In conclusion, this study provides novel insights into the use of αv antisense ODN as an efficacious mechanism for blocking osteoclast function and underscores for the first time the involvement of integrins in bone cell apoptosis. In vivo studies may verify potential application of this ODN as alternative therapy for bone diseases.

RGD Mimetics containing a central hydantoin scaffold: αVβ3 vs αIIbβ3 selectivity requirements

Abstract The synthesis of a series of RGD mimetic α V β 3 antagonists containing a hydantoin scaffold is shown. The results demonstrate some of the structural requirements for the design of selective α V β 3 antagonists (vs α IIb β 3 ) in terms of the Arg-mimetic, the distance between N- and C-terminus and the lipophilic side chain.

Effect of Selective or Combined Inhibition of Integrins αIIbβ3 and αvβ3 on Thrombosis and Neointima After Oversized Porcine Coronary Angioplasty

Background—Thrombosis and neointima formation limit the efficacy of coronary angioplasty (PTCA). Clinical trials have implicated the adhesion molecules integrin αIIbβ3 and integrin αvβ3 in these processes. The roles of these molecules in vascular smooth muscle cell adhesion, platelet aggregation, and the thrombotic and neointimal response to oversize porcine PTCA was investigated by use of a selective αIIbβ3 antagonist (lamifiban), a selective αvβ3 antagonist (VO514), and a combined αIIbβ3/αvβ3 antagonist (G3580). Methods and Results—In vitro, both αvβ3 inhibitors caused dose-dependent inhibition of porcine vascular smooth muscle cell adhesion to vitronectin but not to collagen type IV, fibronectin, or laminin, whereas selective αIIbβ3 inhibition had no effect. Intravenous infusions of either αIIbβ3 inhibitor in swine profoundly inhibited ex vivo platelet aggregation to ADP, whereas selective αvβ3 inhibition had no effect. In a porcine PTCA model, intravenous infusions of the integrin antagonists were adm...

Nuclease stability as dominant factor in the antiviral activity of oligonucleotides directed against HSV-1 IE110

The anti-herpes simplex virus type 1 (anti-HSV-1) efficacy of a series of oligonucleotides was determined as a function of their chemical structure. All oligonucleotides consisted of the same sequence directed against the translation initiation codon of the HSV-1 immediate early gene. The oligonucleotides were modified with phosphorothioate linkage patterns according to various protection strategies against nucleolytic degradation. We show that nuclease resistance is the dominant factor that determines the antiviral efficacy in this series. A minimal protection strategy, consisting of end-capping and pyrimidine protection, has proven to be particularly useful, because it not only yields nuclease-resistant oligonucleotides but also minimizes non-sequence-specific effects.