Robert A Vierkant | Search PubMed

PubMed2026

Menopausal timing and senescent-immune coupling in age-related lobular involution of the human breast: a longitudinal cohort study.

BACKGROUND: Incomplete postmenopausal breast involution leaves persistent epithelial-rich lobules and elevated breast density in about 40% of women and is associated with higher breast cancer risk, but why remodelling stalls remains unclear. METHODS: We studied a longitudinal cohort of 81 women with paired benign breast biopsies (baseline age 45-55 years; follow-up 2-10 years), all with baseline NanoString transcriptomics and two-timepoint digital morphometry, and with multiplex immunofluorescence in spatial-imaging subsets (baseline n = 14-16 depending on panel; follow-up n = 14). A separate postmenopausal endpoint cohort (12 women: eight noninvoluted, four completely involuted), profiled by genome-wide expression array and multiplex immunofluorescence, defined the persistent-lobule phenotype. FINDINGS: Noninvoluted postmenopausal tissue retained a proliferation-competent, tumour-associated epithelial state and showed immune accumulation at lobular boundaries with reduced access to p16+ (senescence-associated) epithelial foci. The same SASP and innate immune programmes that predicted slower involution across the menopausal transition predicted faster involution after menopause. Follow-up boundary CD45→p16 engagement was directionally consistent with this reversal in Pre→Post and Post→Post women. Spatial imaging resolved this reversal into a perimenopausal stall architecture and a postmenopausal clearance-associated architecture marked by direct CD16+ innate-effector engagement of p16+ epithelium; macrophage targeting provided convergent support (two-sided exact permutation interaction p = 0.0077). INTERPRETATION: Menopausal timing conditions whether senescent-immune programmes couple to productive clearance or to spatially uncoupled surveillance and persistent risk-associated tissue. Biomarker interpretation should therefore be anchored to menopausal timing. FUNDING: Casey DeSantis Cancer Fund and US National Cancer Institute.

Humans↗

PubMed2025

Discovery of a MET -driven monogenic cause of steatotic liver disease.

BACKGROUND AND AIMS: Metabolic dysfunction-associated steatotic liver disease affects about a third of adults worldwide and is projected soon to be the leading cause of liver cirrhosis. It occurs when fat accumulates in hepatocytes and can progress to metabolic dysfunction-associated steatohepatitis, liver cirrhosis, and HCC. Metabolic dysfunction-associated steatotic liver disease pathogenesis is believed to involve a combination of genetic and environmental risk factors. Single nucleotide polymorphisms have been implicated, but non-syndromic monogenic causes are lacking. APPROACH AND RESULTS: We identified a novel genetic variant in a familial case of metabolic dysfunction-associated steatohepatitis and performed deep variant functional analysis, including protein modeling, dynamics, and cell-based assays to assess molecular mechanisms of dysfunction and altered cellular signaling. We analyzed exome sequencing data of 3904 individuals with steatotic liver disease (SLD) to identify additional cases and establish the link between specific gene variants and SLD diagnosis. We discovered and functionally validated the NM_000245.4:c.3505A>T; p.(Ile1169Phe) variant in the MET (mesenchymal-epithelial transition) kinase domain as a monogenic cause of SLD. Subsequently, we detected additional ultra-rare, previously uninterpreted, and likely deleterious variants in MET from screening sequencing data. Among individuals with confirmed SLD based on electronic record review, 1.1% (45/3904) had rare predicted deleterious MET variants. Eight of 45 (17.7%) individuals had predicted deleterious variants in the MET kinase domain confirmed to be functionally like the familial case variant. CONCLUSIONS: We report the first germline nonmalignant rare MET -driven disease, a monogenic form of SLD.

Adult↗