👤 Ilya M Nasrallah

This study aimed to compare positron emission tomography (PET) and plasma-based temporal modeling of amyloid and tau biomarkers in Alzheimer's disease. Longitudinal amyloid PET (n = 1,097, mean age ± SD = 72.5 ± 7.38 year, 51.4% male), Plasma and PET models generated similar results for estimated amyloid and tau onset, with stronger model agreement for tau (r = 0.88[0.86, 0.89], t = 57.4, p < 0.001) than amyloid (r = 0.75[0.72, 0.77], t = 37.4, p < 0.001) onset. Accuracy of estimated onset compared to actual onset was high within modality (mean absolute error [MAE] ≤ 2.03) with slightly greater error (MAE 3.09-3.42) when comparing across modalities (ie, plasma to PET). For both plasma and PET, earlier tau onset was associated with younger amyloid onset, female sex, and ≥1 apolipoprotein (ApoE) ε4 allele. Earlier dementia onset after tau was associated with later tau onset for both plasma and PET, while male sex was associated with shorter tau to dementia gap in plasma models. Temporal modeling of plasma biomarkers provides comparable information to PET-based models, particularly for tau onset age, and can serve as a widely accessible tool for clinical assessment of biological disease severity. ANN NEUROL 2026. Show less

People with HIV (PWH) and undetectable virus experience elevated cardiovascular risk independent of traditional risk factors. Vascular inflammation may contribute to this residual risk. The perivascular fat attenuation index (FAI), derived from coronary computed tomography angiography (CCTA), is a biomarker of coronary inflammation. Lipoprotein(a) [Lp(a)] carries oxidized phospholipids that may promote inflammation. Statins have demonstrated cardiovascular benefit in PWH, including pleiotropic anti-inflammatory effects. This study assessed the associations of Lp(a) and of statin use with coronary inflammation (FAI) in men with HIV (MWH). We analysed FAI of the left anterior descending (LAD) and the right coronary arteries (RCA) in 583 men from the Multicenter AIDS Cohort Study, a prospective, multicentre cohort study, including 280 with undetectable HIV RNA, <50 copies/ml. Associations between log Lp(a) was associated with increased coronary inflammation, independent of traditional cardiovascular risk factors, in MWH with undetectable virus. Statin therapy did not modify the relationship between coronary inflammation and Lp(a). Show less

Lipoprotein(a) [Lp(a)] is a primarily genetically determined, causal and independent risk factor for atherosclerotic cardiovascular disease (ASCVD). Lp(a) levels are stable, unaffected by lifestyle, and best measured using isoform-insensitive, molar-based assays. Current guidelines from the European Atherosclerosis Society and U.S. National Lipid Association recommend a one-time Lp(a) measurement in all adults. Cascade testing is advised in affected families. Elevated Lp(a) levels are associated with increased risk of coronary artery disease, myocardial infarction incidence and recurrence, and aortic stenosis onset and progression. In cerebrovascular disease, high Lp(a) is linked to large artery ischemic stroke incidence and recurrence, as well as poor functional outcomes. Associations with venous thromboembolism are limited to prothrombotic states and extreme Lp(a) concentrations. Elevated levels (≥50 mg/dL or ≥125 nmol/L) should prompt intensified risk factor modification. There are no currently approved lipid-lowering therapies that substantially reduce Lp(a) levels. Novel agents to lower Lp(a) include antisense oligonucleotides, small interfering ribonucleic acid and small molecules, all of which have shown promising results in phase 2 trials. Ongoing phase 3 trials will evaluate the causal relationship between Lp(a) and ASCVD, and whether lowering Lp(a) reduces cardiovascular outcomes. Show less

Lipoprotein(a) [Lp(a)] is a primarily genetically determined, low-density lipoprotein-like particle that plays an important role in atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve disease (CAVD). Despite optimal control of traditional lipid levels, elevated lipoprotein(a) [Lp(a)] remains a significant contributor to residual cardiovascular risk, affecting up to 20% of the global population. We performed a literature search of PubMed/Medline and Google Scholar until July 2025 to provide a comprehensive overview of the genetics, structure, metabolism, and molecular mechanisms underlying Lp(a)'s pathogenicity. Structurally, Lp(a) consists of an LDL-like core covalently bound to apolipoprotein(a) [apo(a)], a polymorphic glycoprotein characterized by kringle IV type 2 (KIV-2) repeat variability. This copy number variation is the primary determinant of apo(a) isoform size and plasma Lp(a) levels. Small isoforms are produced more efficiently, resulting in higher concentrations. Lp(a) is synthesized in hepatocytes, and its plasma levels are predominantly governed by production rather than clearance. It carries a high burden of oxidized phospholipids (OxPLs), which confer pro-inflammatory and pro-atherogenic properties. Lp(a) promotes arterial inflammation, endothelial dysfunction, monocyte activation and impaired fibrinolysis via competition with plasminogen. It also plays a direct pathogenic role in valvular calcification by delivering OxPLs and autotaxin to valve interstitial cells, triggering osteogenic signaling cascades. While environmental factors such as inflammation and hormonal status can transiently modulate levels, genetic variation overwhelmingly dictates lifelong Lp(a) burden. As novel agents targeting Lp(a) enter late-stage clinical trials, mechanistic insights into Lp(a) biology will be essential to risk stratification and future clinical management. Show less

The peri- and early post-infarction period carries an increased risk of recurrent ischemic events. Oxidized phospholipids (OxPLs) are pro-inflammatory and contribute to plaque instability and thrombosis. This study aimed to: (1) assess changes, during the early post-MI period in OxPL-apo(a) and OxPL-apoB, (2) evaluate the effect of PCSK9 inhibition on these changes, and (3) explore their relationships with the changes in Lp(a) and LDL-C. Ninety-six participants with NSTEMI or STEMI were randomized to receive placebo (n = 48) or 420 mg subcutaneous evolocumab (n = 48) within 24 h of admission. OxPL-apo(a), OxPL-apoB, Lp(a), and LDL-C levels were measured at baseline and 30 days post-MI. In the placebo group, OxPL-apo(a) increased from 52.6 [19.3, 106.5] nmol/L at baseline to 61.7 [31.5, 116.9] nmol/L at 30 days (p = 0.014), and OxPL-apoB rose from 6.7 [3.1, 21] nmol/L to 8.8 [3.7, 23] nmol/L (p = 0.0045). In contrast, no significant changes were observed for OxPL-apo(a) (p = 0.17) or OxPL-apoB (p = 0.058) in the evolocumab group. OxPL-apo(a) correlated strongly with Lp(a) at baseline (r = 0.93, p < 0.001) and 30 days (r = 0.94, p < 0.001), and OxPL-apoB correlated similarly (baseline: r = 0.92, p < 0.001; 30 days: r = 0.93, p < 0.001). No correlation was observed between OxPLs and LDL-C. OxPL-apo(a) and OxPL-apoB levels were strongly correlated with Lp(a) and increased during the early post-infarction period. This increase was prevented by in-hospital administration of a PCSK9 inhibitor. These findings provide new insights into early changes in OxPLs following acute MI and suggest a protective role for PCSK9 inhibition during this critical period. Show less

Xeroderma Pigmentosum C is a dermal hereditary disease caused by a mutation in the DNA damage recognition protein XPC that belongs to the Nucleotide excision repair pathway. XPC patients display heightened sensitivity to light and an inability to mend DNA damage caused by UV radiation, resulting in the accumulation of lesions that can transform into mutations and eventually lead to cancer. To address this issue, we conducted a screening of siRNAs targeting human kinases, given their involvement in various DNA repair pathways, aiming to restore normal cellular behavior. We introduced this siRNA library into both normal and XPC patient-derived fibroblasts, followed by UVB exposure to induce DNA damage. We assessed the reversal of the XPC phenotype by measuring reduced photosensitivity and enhanced DNA repair. Among the 1292 kinase-targeting siRNAs screened, twenty-eight showed significant improvement in cellular survival compared to cells transfected with non-targeting siRNA after UV exposure in XPC cells. From these candidates, PIK3C3 and LATS1 were identified as particularly effective, promoting over 20% repair of 6-4 photoproduct (6-4PP) DNA lesions. Specifically targeting the autophagy-related protein PIK3C3 alone demonstrated remarkable photoprotective effects in XPC-affected cells, which were validated in primary XPC patient fibroblasts and CRISPR-Cas9 engineered XPC knockout keratinocytes. PIK3C3 knock down in XP-C cells ameliorated in UVB dose response analysis, decreased apoptosis with no effect on proliferation. More importantly, PIK3C3 knock down was found to induce an increase in UVRAG expression, a previously reported cDNA conveying lower photosensitivity in XP-C cells. Thus, attempts to improve the XPC photosensitive and deficient repair phenotype using PIK3C3 inhibitors could pave a way for new therapeutic approaches delaying or preventing tumor initiation. Show less

Variants in cardiac myosin-binding protein C (cMyBP-C) are the leading cause of inherited hypertrophic cardiomyopathy (HCM), demonstrating the key role that cMyBP-C plays in the heart's contractile machinery. To investigate the Show less

Myosin-binding protein C 3 (MYBPC3) variants are the most common cause of hypertrophic cardiomyopathy (HCM). HCM is a complex cardiac disorder due to its significant genetic and clinical heterogeneity. MYBPC3 variants genotype-phenotype associations remain poorly understood. We investigated the impact of two novel human MYBPC3 splice-site variants: V1: c.654+2₆₅₄₊₄dupTGG targeting exon 5 using morpholino MOe5i5; and V2: c.772+1G>A targeting exon 6 using MOe6i6; located within C1 domain of cMyBP-C protein, known to be critical in regulating sarcomere structure and contractility. Zebrafish MOe5i5 and MOe6i6 morphants recapitulated typical characteristics of human HCM with cardiac phenotypes of varying severity, including reduced cardiomyocyte count, thickened ventricular myocardial wall, a drastic reduction in heart rate, stroke volume, and cardiac output. Analysis of all cardiac morphological and functional parameters demonstrated that V2 cardiac phenotype was more severe than V1. Coinjection with synthetic human MYBPC3 messenger RNA (mRNA) partially rescued disparate cardiac phenotypes in each zebrafish morphant. While human MYBPC3 mRNA partially restored the decreased heart rate in V1 morphants and displayed increased percentages of ejection fraction, fractional shortening, and area change, it failed to revert the V1 ventricular myocardial thickness. These results suggest a possible V1 impact on cardiac contractility. In contrast, attempts to rescue V2 morphants only restored the ventricular myocardial wall hypertrophy phenotype but had no significant effect on impaired heart rate, suggesting a potential V2 impact on the cardiac structure. Our study provides evidence of an association between MYBPC3 exon-specific cardiac phenotypes in the zebrafish model providing important insights into how these genetic variants contribute to HCM disease. Show less

Hypertrophic cardiomyopathy (HCM) is a common autosomal dominant genetic cardiovascular disorder marked by genetic and phenotypic heterogeneity. Mutations in the gene encodes the cardiac myosin-binding protein C, cMYBPC3 is amongst the various sarcomeric genes that are associated with HCM. These mutations produce mutated mRNAs and truncated cMyBP-C proteins. In this review, we will discuss the implications and molecular mechanisms involved in MYBPC3 different mutations. Further, we will highlight the novel targets that can be developed into potential therapeutics for the treatment of HMC. J. Cell. Physiol. 232: 1650-1659, 2017. © 2016 Wiley Periodicals, Inc. Show less