Damir Quien

Dr. Damir Quien

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 August 2023 in European Journal of Surgical Oncology
Verified
Journal Article
Closed access
ATAnte Tavra
Ante Tavra
DQDamir Quien
Damir Quien
OBOgnjen Barcot
Ognjen Barcot

Verified
Journal Article
Open access
PDF file
DQDamir Quien
Damir Quien
JPJelena Korać Prlić
Jelena Korać Prlić
KVKatarina Vilović
Katarina Vilović
Zenon PogorelićZenon Pogorelić
Zenon Pogorelić
MBMatija Boric
Matija Boric
MDMarina Degoricija
Marina Degoricija
Aging of the gut involves progressive changes in structure, function, and microbial composition, which impact overall health. The vermiform appendix extends from the apex of the cecum; it contains gut-associated lymphoid tissue and serves as a reservoir of gut microbiota. This study investigates histologic and gene expression changes in 20 morphologically normal appendiceal samples obtained from pediatric (n = 5), adult (n = 8), and geriatric (n = 7) patients. Histologic analysis revealed a higher prevalence of lymphoid follicles reduction and the presence of fibrous obliteration of the appendiceal tip in aged samples. RNA sequencing identified 1004 differentially expressed genes (385 upregulated and 619 downregulated; p < 0.05) between the adult and geriatric population. Upregulated pathways were enriched for oxidative stress response, cholesterol metabolism, and mucosal barrier maintenance, including NRF2 targets (NQO1, MGST1), suggesting enhanced antioxidant activity. Downregulated genes were associated with synaptic signaling, ion channel regulation, and neuronal adhesion (e.g., GRIA2, RET, NOS1, NCAM2, CNTN1), reflecting age-related decline in enteric neuronal integrity. Across all age groups, 25 protein-coding genes showed progressive expression shifts with aging, including upregulation of CLDN2, MUC2, and GDF15, and downregulation of NOG and NELL2, indicating barrier loosening, chronic inflammation, and reduced regenerative potential. These findings suggest that aging of the vermiform appendix recapitulates key processes of intestinal aging, including oxidative stress, inflammaging, and neuronal loss, supporting its potential use as a model tissue for studying gut aging mechanisms.