👤 Philip James Clare

We employed a causal inference framework to estimate the counterfactual dose-response effects of light-intensity physical activity (LPA) on mortality across low, medium and high moderate- to vigorous-intensity physical activity (MVPA) levels, and the lower and higher thresholds of current MVPA recommendations. Eligible participants from the UK Biobank (n=71 715) were included in the current study. LPA and MVPA were measured via accelerometers, and mortality data were derived from death registry. Flexible parametric survival models were used under the counterfactual framework to estimate the marginal predicted probability of death after 10 years of follow-up. During a median follow-up period of 8.0 years, 2195 deaths occurred. A non-linear dose-response effect of LPA on all-cause mortality was evident, and the effect diminished as MVPA level increased. If all participants achieved the lower threshold of the WHO recommended 22 min/day of MVPA, the 10-year probability of death would be expected to decrease from 9.5% at 60 min/day LPA to 4.2% at 360 min/day. If all participants achieved the higher threshold of 44 min/day of MVPA, the 10-year probability of death would be expected to decrease from 6.6% at 60 min/day of LPA to 3.7% at 345 min/day. Across the MVPA values examined, the optimal dose for LPA ranged from 195 to 225 min/day. LPA may complement MVPA to reduce risk of all-cause mortality, particularly among those with low MVPA or those unable to engage in higher-intensity activities. Our study highlights the potential for integrating LPA into public health strategies and future physical activity guidelines. Show less

Alzheimer disease neuropathologic change (ADNC) is the most common pathology underlying cognitive impairment and dementia in the aging population, but there is significant variation in outcome between affected individuals. Moreover, other common neurodegenerative processes are often concurrent and may significantly worsen cognition, but the degree to which these processes interact and affect the We performed a cross-sectional cohort study of 586 participants from the National Alzheimer’s Coordinating Center (NACC) database, who were ≥ 65 years of age and displayed high-level ADNC at autopsy, and who had available longitudinal cognitive data and Clinical Dementia Rating (CDR) performed within the final 24 months of life. This cohort was subdivided into “resilient” individuals/those with minimal progression of cognitive decline (MinP; Individuals with rapid progression were more likely to have at least one These data suggest that resilience and progression in ADNC are impacted by AD-relevant genetics and the severity of late-stage ADNC (even within the narrow range of values compatible with high-level ADNC), additional pathologic features, and potentially the clinical management of underlying systemic disorders. The online version contains supplementary material available at 10.1186/s13195-025-01904-6. Show less

The ovarian hormones estrogen and progesterone (EP) are implicated in breast cancer causation. A specific consequence of progesterone exposure is the expansion of the mammary stem cell (MSC) and luminal progenitor (LP) compartments. We hypothesized that this effect, and its molecular facilitators, could be abrogated by progesterone receptor (PR) antagonists administered in a mouse model. Ovariectomized FVB mice were randomized to 14 days of treatment: sham, EP, EP + telapristone (EP + TPA), EP + mifepristone (EP + MFP). Mice were then sacrificed, mammary glands harvested, and mammary epithelial cell lineages separated by flow cytometry using cell surface markers. RNA from each lineage was sequenced and differential gene expression was analyzed using DESeq. Quantitative PCR was performed to confirm the candidate genes discovered in RNA seq. ANOVA with Tukey post hoc analysis was performed to compare relative expression. Alternative splicing events were examined using the rMATs multivariate analysis tool. Significant increases in the MSC and luminal mature (LM) cell fractions were observed following EP treatment compared to control (p < 0.01 and p < 0.05, respectively), whereas the LP fraction was significantly reduced (p < 0.05). These hormone-induced effects were reversed upon exposure to TPA and MFP (p < 0.01 for both). Gene Ontology analysis of RNA-sequencing data showed EP-induced enrichment of several pathways, with the largest effect on Wnt signaling in MSC, significantly repressed by PR inhibitors. In LP cells, significant induction of Wnt4 and Rankl, and Wnt pathway intermediates Lrp2 and Axin2 (confirmed by qRTPCR) were reversed by TPA and MFP (p < 0.0001). Downstream signaling intermediates of these pathways (Lrp5, Mmp7) showed similar effects. Expression of markers of epithelial-mesenchymal transition (Cdh1, Cdh3) and the induction of EMT regulators (Zeb1, Zeb2, Gli3, Snai1, and Ptch2) were significantly responsive to progesterone. EP treatment was associated with large-scale alternative splicing events, with an enrichment of motifs associated with Srsf, Esrp, and Rbfox families. Exon skipping was observed in Cdh1, Enah, and Brd4. PR inhibition reverses known tumorigenic pathways in the mammary gland and suppresses a previously unknown effect of progesterone on RNA splicing events. In total, our results strengthen the case for reconsideration of PR inhibitors for breast cancer prevention. Show less