Inhomogeneous Diastereomeric Composition of Mongersen Antisense Phosphorothioate Oligonucleotide Preparations and Related Pharmacological Activity Impairment.

Mongersen is a 21-mer antisense oligonucleotide designed to downregulate Mothers against decapentaplegic homolog 7 (SMAD7) expression to treat Crohn's disease. Mongersen was manufactured in numerous batches at different scales during several years of clinical development, which all appeared identical, using common physicochemical analytical techniques, while only phosphorous-31 nuclear magnetic resonance (31P-NMR) in solution showed marked differences. Close-up analysis of 27 mongersen batches revealed marked differences in SMAD7 downregulation in a cell-based assay. Principal component analysis of 31P-NMR profiles showed strong correlation with SMAD7 downregulation and, therefore, with pharmacological efficacy in vitro. Mongersen contains 20 phosphorothioate (PS) linkages, whose chirality (Rp/Sp) was not controlled during manufacturing. A different diastereomeric composition throughout batches would lead to superimposable analytical data, but to distinct 31P-NMR profiles, as indeed we found. We tentatively suggest that this may be the origin of different biological activity. As similar manifolds are expected for other PS-based oligonucleotides, the protocol described here provides a general method to identify PS chirality issues and a chemometric tool to score each preparation for this elusive feature.

Advanced glycation end-products and arterial stiffness in hypertension.

BACKGROUND: The formation of advanced glycation end-products is associated with arterial stiffness in experimental models and alagebrium (formerly known as ALT-711), an advanced glycation end-product cross-link breaker, has been shown to reduce arterial stiffness in elderly subjects. METHODS: We related plasma concentrations of advanced glycation end-products (AGEs), measured using a noncompetitive immunoassay, and markers of aortic stiffness-pulse wave velocity (PWV) and augmentation index (AIx), a measure of aortic wave reflection-in 46 subjects, aged 47 +/- 2 years, comprising 30 untreated hypertensive and 16 normotensive subjects. Results were analyzed using univariate and multiple logistic regression analysis. RESULTS: Plasma AGEs were significantly higher in hypertensive than in normotensive subjects (7.8 +/- 1 v 3 +/- 1 mug/ml; P < .0001). There was a significant relationship between plasma AGEs and aortic PWV (r = 0.49, P < .01), but not with AIx. In a stepwise regression model age, plasma AGE levels, smoking status, and total cholesterol explained 67% of the variability in PWV. For AIx, the only variables that entered the model were age, gender, and heart rate (R(2) = 0.53, P < .0001) with no contribution from plasma AGEs. CONCLUSIONS: Concentration of plasma AGEs is significantly higher in hypertensive than in normotensive subjects and related to aortic stiffness independent of age and blood pressure, with no relationship with aortic wave reflection. Plasma AGEs may play a blood pressure-independent role in large but not small vessel remodeling in essential hypertension.

Aging is associated with increased matrix metalloproteinase-2 activity in the human aorta.

BACKGROUND: Aging is a major risk factor for the development of arterial stiffness and vascular disease, and it is related to the upregulation of matrix metalloproteinase-2 (MMP-2) in the aorta of rats and nonhuman primates. This study aimed to determine whether MMP activity in the human vasculature changes with aging. We also assessed regional differences in MMP activity at two locations in the arterial tree, the aorta and the internal mammary artery (IMA). METHODS: Both MMP-2 and MMP-9 activity in the human aorta and IMA were determined by gelatin zymography and were localized within the tissue using in situ zymography. Tissue inhibitor of metalloproteinase-2 (TIMP-2) levels was determined by Western blot. RESULTS: Active MMP-2 (but not pro-MMP-2, pro-MMP-9, or active MMP-9) was positively correlated with age in the human aorta (r = 0.65; P < .001) but not in the IMA. Active MMP-2 and TIMP-2 (but not pro-MMP-2 or pro- or active MMP-9) levels are higher in the aorta than in the IMA (P < .001; P < .05). In the aorta, MMP activity is highest in the intima and is also detectable in the media and adventitia. To a lesser extent, MMP activity is present in all layers of the IMA. CONCLUSIONS: This study demonstrates that age-related MMP-2 upregulation occurs in the human aorta but not in the IMA.