Biology subjects

Olson, J. D.

Publications and source records attributed to Olson, J. D..

4 recordsLinked to original sources

bioRxiv2026

Pseudo-observations of longevity improve detection of resilience-associated genes in the Radiation Late Effects Cohort of rhesus macaques.

Non-human primates are an ideal model for interrogating the genetic basis of human lifespan and resilience due to their long lifespan compared to other model organisms, development of similar age-related chronic conditions, and genetic similarity. However, like humans, statistical methods for modeling survival suffer from the challenges of dealing with non-proportionality of hazards, large numbers of living individuals that must be censored, and loss-to-follow-up over studies that may last a decade or more. Here we overcome these challenges through the use of pseudo-observations of Restricted Mean Survival Time as a measure of resilience to the acute challenge of radiation exposure and chronic challenges of aging and a Western-style diet in rhesus macaques (Macaca mulatta) from the Wake Forest Non-Human Primate Radiation Late Effects Cohort. Our whole-exome analysis used Genome-wide Efficient Mixed Model Association (GEMMA) to identify variants associated with longevity, and a subsequent Gene Set Enrichment Analysis (GSEA) highlighted the cadherin and integrin signaling pathways as central to this resilience. As dysregulation of cell adhesion and extracellular matrix signaling is central to the development of fibrosis, we tested the functional relevance of these signals using a targeted Combined Annotation Dependent Depletion (CADD) score-weighted Sequence Kernel Association Test-Optimal (SKAT-O) analysis of GSEA leading-edge genes from both the cadherin and integrin pathways. This linked variant burden in PCDHGA5, PCDHGA3, PCDHGB2, PCDHA11, and PSENEN to the severity of myocardial fibrosis, and in IBSP, PDGFD, and LAMC2 to the severity of pulmonary fibrosis observed at necropsy. Critically, we note that the genetic variants are not caused by the radiation but rather create an underlying risk for disease that is then exacerbated by the acute and persistent stressors challenging these animals' intrinsic resilience. The success of this method in identifying biologically relevant genetic variants underlying survival in animals undergoing a strong challenge to their resilience highlights not only the role of genes predisposing animals to fibrosis in lifespan, but the overall utility of pseudo-observations in overcoming the limitations of survival analyses in humans and other long-lived species.

genomics↗

bioRxiv2026

Serum pro-N-cadherin: a biomarker of cardiac fibrosis and diastolic dysfunction in irradiated non-human primates

BackgroundThe delayed effects of radiation exposure on the heart often manifest as cardiac fibrosis and diastolic dysfunction, which can develop years after exposure. However, no FDA-approved serological biomarker is available to assess the risk of individuals for developing radiation-related heart disease (RRHD). ObjectivesSerum pro-N-cadherin (PNC) has shown promise as a marker for predicting the onset of heart failure in the general population. We hypothesize that serum PNC levels will correlate with the risk of RRHD following radiation exposure. MethodsWe examined male non-human primates (NHPs) exposed to total-body irradiation (TBI) and unirradiated controls from the Wake Forest University radiation late effects cohort. NHPs exhibited cardiac fibrosis scores ranging from less severe (F0-1) to more severe (F2-3). Cardiac tissue samples collected at necropsy, median 6.8 years post-irradiation, were stained for PNC by immunohistochemistry. PNC was quantified in longitudinal serum samples collected 2, 1 and 0 years before necropsy. The associations of serum PNC levels with cardiac fibrosis scores and echocardiographic parameters were examined. ResultsHistological examinations showed aberrant localization of PNC in NHPs with cardiac fibrosis. Elevated serum PNC levels significantly correlated with severe cardiac fibrosis (AUC = 0.81, p = 0.006) and echocardiogram parameters of diastolic dysfunction. Cardiac fibrosis was the only measured comorbidity with a significant difference in serum PNC. ConclusionsOur results demonstrate that serum PNC significantly correlates with cardiac fibrosis and diastolic dysfunction in irradiated NHPs. These findings pave the way for future clinical studies to develop serum PNC as a biomarker of RRHD in humans. HIGHLIGHTSO_LIRadiation-related heart disease is an often under-recognized complication of radiation exposure and radiation therapy, which has no FDA-approved biomarkers for assessing risk. C_LIO_LIOur results reveal that serum pro-N-cadherin is a biomarker of cardiac fibrosis and diastolic dysfunction in non-human primates that survived radiation exposure. C_LIO_LIThis study lays the foundation for further research into the development of serum pro-N-cadherin as a biomarker for assessing the risk of radiation-related heart disease in humans. C_LI

physiology↗

bioRxiv2026

Developing And Internally Validating AI-Based Aging Resilience Biomarkers in Non-Human Primates

Quantifying biological aging is crucial for understanding functional decline before the onset of morbidity. While many accelerated aging and frailty measures based on clinical data exist for humans and several for rodent models of aging, there are few options for non-human primates (NHPs). NHP clinical data has several unique features including a lack of clinically delineated normative values for features and variability in data collection over long lifespans. There are also wide discrepancies in the number of available clinical measures and number of animals across data sets. To address these challenges, we developed and validated "Aging Resilience" (AR) metrics using longitudinal, routine clinical data from two distinct non-human primate cohorts: 4,328 baboons and 281 rhesus macaques. We trained five computational models--including Linear Mixed-Effects Models, Random Forest, and Recurrent Neural Networks (RNN)--to predict chronological age, subsequently deriving AR metrics that represent the velocity (Rate of Aging) and cumulative burden (Normalized Cumulative Aging) of physiological deviation. While linear models achieved high precision in predicting chronological age (test R2 up to 0.99), they correlated poorly with actual lifespan. In contrast, AR metrics derived from non-linear models (RNN and Random Forest) displayed strong predictive validity for mortality (Pearsons r > 0.8). These findings highlight a critical paradox: models that best predict chronological age do not necessarily capture the biological resilience determining healthspan. This study establishes a scalable framework for monitoring biological aging in translational models using standard veterinary records.

bioinformatics↗

bioRxiv2021

Probing Loop-Mediated Isothermal Amplification (LAMP) targeting two gene-fragments of rose rosette virus

This study explores the development of Loop-mediated isothermal amplification of DNA (LAMP) for detection of rose rosette emaravirus (RRV), a technique with the potential to be translated to rose nurseries. RRV is a negative-sense single-stranded RNA Emaravirus and causal agent of the rose rosette disease (RRD). Transmission of RRV is by Phyllocoptes fructiphilus, an eriophyid mite. Although RRV symptoms are characteristics, early visual diagnosis of RRD can be misleading and confusing since it may appear similar to herbicide damage. Two sets of RRV gene sequences composed of twenty-two accessions of RRV-P3 (RNA 3) and another twenty-four from RRV-P4 (RNA 4) were analyzed and two sets of four LAMP primers were designed for broad-range detection of RRV isolates. The direct antigen-capture method for direct trapping of RRV in plastic was used for RNA extraction followed by cDNA synthesis. LAMP reactions were optimized for Bst 2.0 DNA polymerase using the outer RRV-F3/RRV-B3 primers, and internal RRV-FIP/RRV-BIP primers. LAMP reactions were for 1 hour at 64{degrees}C (RRV-P3) and 66.5{degrees}C (RRV-P4) using either a thermocycler or a portable dry bath. LAMP was also optimized using DNA polymerase GspSSD LD using the same RRV sets of primers. RRV was detected in symptomatic and non-symptomatic RRD tissue from Oklahoma. The limit of detection (LoD) using Bst 2.0 LAMP was 1pg/L and 1 fg/L with GspSSD LD quantitative LAMP. The LoD of pre-reaction hydroxy naphthol blue (HNB, 120 M) for colorimetric (visual) reactions was 10 pg/L and 0.1 pg/L using SYBR green I (1:10 dilution) in colorimetric post-reactions. No cross-reactivity was detected in LAMP reaction testing cDNAs of eight commonly co-infecting rose viruses (INSV, ArMV, MSpV, TSWV, ApMV, PNRSV, ToRSV, and TMV), and one virus taxonomically related to RRV (HPWMoV). RNA from healthy rose tissues and non-template controls (water) were included in all LAMP assays.

molecular biology↗