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Pirhaji, L.

Publications and source records attributed to Pirhaji, L..

2 recordsLinked to original sources

mzLearn, a data-driven LC/MS signal detection algorithm, enables pre-trained generative models for untargeted metabolomics

Metabolite alterations are linked to diseases, yet large-scale untargeted metabolomics remains constrained by challenges in signal detection and integration of diverse datasets for developing pre-trained generative models. Here, we introduce mzLearn, a data-driven MS1 signal-detection and alignment method that runs from mzML files without user-set parameters. Across 15 public datasets, mzLearn detects 11,442 signals on average vs 7,100 (XCMS) and 4,655 (ASARI), with higher TP (89.0% vs 77.4% vs 49.6%) and lower FP (12.5% vs 17.3% vs 18.8%), while correcting instrument drifts across large cohorts without experimental QC samples. mzLearn detected 2,736 robust metabolite signals from 22 public studies (20,548 blood samples), enabling the development of pre-trained variational autoencoder for untargeted metabolomics. Learned metabolite representations reflected demographic data and when fine-tuned on unseen renal cell carcinoma data, improved risk stratification and overall survival predictions, while feature-importance analysis (SHAP) highlighted biologically plausible lipid and carnitine signals. By producing a consistent, high-quality MS1 feature matrix at scale, mzLearn paves the way for developing pre-trained foundation models for untargeted metabolomics.

bioinformatics↗

APOE4 is Associated with Differential Regional Vulnerability to Bioenergetic Deficits in Aged APOE Mice

The {varepsilon}4 allele of apolipoprotein E (APOE) is the dominant genetic risk factor for late-onset Alzheimers disease (AD). However, the reason for the association between APOE4 and AD remains unclear. While much of the research has focused on the ability of the apoE4 protein to increase the aggregation and decrease the clearance of A{beta}, there is also an abundance of data showing that APOE4 negatively impacts many additional processes in the brain, including bioenergetics. In order to gain a more comprehensive understanding of the APOE4s role in AD pathogenesis, we performed a multi-omic analysis of APOE4 vs. APOE3 expression in the entorhinal cortex (EC) and primary visual cortex (PVC) of aged APOE mice. These studies revealed region-specific alterations in several bioenergetic pathways, including oxidative phosphorylation (OxPhos), the TCA-cycle and fatty acid metabolism. Follow-up analysis utilizing the Seahorse platform revealed decreased mitochondrial respiration in the hippocampus and cortex of aged APOE4 vs. APOE3 mice, but not in the EC of these mice. Additional studies, as well as the original multi-omic data suggest that bioernergetic pathways in the EC of aged APOE mice may be differentially regulated by APOE4 expression. Given the importance of the EC as one of the first regions to be affected by AD pathology in humans, this differential bionenergetic regulation observed in the EC vs. other brain regions of aged APOE4 mice may play an important role in the pathogenesis of AD, particularly among APOE4 carriers.

neuroscience↗