👤 Dedra S Buchwald

American Indians have a high population risk for cerebrovascular disease, vascular brain injury (VBI), and dementia. The apolipoprotein ( We analyzed data from a population-based, longitudinal cohort of American Indians aged 64-95 years from the Strong Heart Study recruited from Northern Plains, Southern Plains, and Southwest regions. Magnetic resonance imaging markers included infarcts, lacunes, hemorrhages, and WMH. The sample size was 395 participants with a mean age of 71.3 (4.7) years and was comprised of 313 non-ε4-carriers and 82 ε4-carriers, predominantly female (70.1%). Cross-sectional analyses indicated no significant associations between Our findings echo previous work that Show less

Chemically modified small interfering RNAs (siRNAs) are a promising drug class that silences disease-causing genes via mRNA degradation. Both siRNA-specific features (e.g. sequence, modification pattern, and structure) and target mRNA-specific factors contribute to observed efficacy. Systematically defining the relative contributions of siRNA sequence, structure, and modification pattern versus the native context of the target mRNA is necessary to inform design considerations and facilitate the widespread application of this therapeutic platform. To address this, we synthesized a panel of ∼1260 differentially modified siRNAs and evaluated their silencing efficiency against therapeutically relevant mRNAs (APP, BACE1, MAPT, and SNCA) using both reporter-based and native expression assays. Our results demonstrate that the siRNA modification pattern (e.g. level of 2'-O-methyl content) significantly impacts efficacy, while structural features (e.g. symmetric versus asymmetric configurations) do not. Furthermore, we observed substantial differences in the number of effective siRNAs identified per target. These target-specific differences in hit rates are largely mitigated when efficacy is tested in the context of a reporter assay, confirming that native mRNA-specific features influence siRNA performance. Key target-specific factors, including exon usage, polyadenylation site selection, and ribosomal occupancy, partially explained efficacy variability. These insights led to a proposed framework of parameters for optimizing therapeutic siRNA design. Show less

Biomarkers of early pathogenesis of type 1 diabetes (T1D) are crucial to enable effective prevention measures in at-risk populations before significant damage occurs to their insulin producing beta-cell mass. We recently introduced the concept of integrated parallel multi-omics and employed a novel data augmentation approach which identified promising candidate biomarkers from a small cohort of high-risk T1D subjects. We now validate selected biomarkers to generate a potential composite signature of T1D risk. Twelve candidate biomarkers, which were identified in the augmented data and selected based on their fold-change relative to healthy controls and cross-reference to proteomics data previously obtained in the expansive TEDDY and DAISY cohorts, were measured in the original samples by ELISA. All 12 biomarkers had established connections with lipid/lipoprotein metabolism, immune function, inflammation, and diabetes, but only 7 were found to be markedly changed in the high-risk subjects compared to the healthy controls: ApoC1 and PON1 were reduced while CETP, CD36, FGFR1, IGHM, PCSK9, SOD1, and VCAM1 were elevated. Results further highlight the promise of our data augmentation approach in unmasking important patterns and pathologically significant features in parallel multi-omics datasets obtained from small sample cohorts to facilitate the identification of promising candidate T1D biomarkers for downstream validation. They also support the potential utility of a composite biomarker signature of T1D risk characterized by the changes in the above markers. Show less

The -1131T>C polymorphism in the newly identified apolipoprotein A5 (APOA5) gene has been associated with elevated plasma triglycerides. We determined its incidence in 915 patients attending a lipid outpatient clinic. The frequency of the C allele was significantly higher in patients with triglycerides above the 90th percentile and patients with type III hyperlipidemia compared to those with hypercholesterolemia. The C allele was associated with increased plasma triglycerides and decreased plasma HDL cholesterol, conditions associated with an increased risk of coronary heart disease. The effects on plasma lipids were only observed in overweight (BMI>25) patients and were greater in patients who were also carriers of a least one epsilon4 allele in the APOE gene. Thus additional genetic and/or metabolic factors are required in order for the triglyceride raising and HDL lowering effect of the -1131T>C polymorphism in APOA5 to be expressed. Show less