Biology subjects

Sharkey, C.

Publications and source records attributed to Sharkey, C..

3 recordsLinked to original sources

bioRxiv2025

Stem-like Prostate Remodeling in Obesity Mediates Resistance to 5α-Reductase Inhibition Therapy in BPH

Benign prostatic hyperplasia (BPH) is closely associated with obesity and metabolic syndrome. Although 5-reductase inhibitors (5ARIs) are widely used to treat BPH, their effectiveness varies significantly, particularly in obese patients. However, the mechanisms by which obesity affects prostate growth and modulates therapeutic responses remain poorly understood. In mice, highfat diet (HFD) increased prostate weight and induced SRD5A2-independent epithelial remodeling with expansion of proximal urethral luminal epithelial cells. ScRNA-seq of prostate tissues from Srd5a2null and control mice on HFD showed enrichment of proximal stem-like populations, reduced androgen signaling, and activation of WNT and NOTCH pathways via heightened stromal-epithelial crosstalk. Clinically, BMI gain, regardless of 5ARI use, correlated with transition zone growth, stronger activity of stem-cell signatures, reduced SRD5A2, and androgen signaling downregulation. Xenium spatial profiling indicated that BMI gain expands stem-like epithelial populations and a NOTCHenriched periepithelial stromal niche surrounding epithelial compartments, supporting stemness. Patients with substantial BMI gain were less responsive to 5ARI, whereas weight control plus 5ARI therapy synergistically improved outcomes. In conclusion, BMI gain promotes proximal prostate enlargement through an SRD5A2-independent stem-like cell mediated pathway that blunts 5ARI efficacy. Combining pharmacotherapy with weight control yields superior efficacy and supports individualized management of BPH.

pathology↗

bioRxiv2025

Stromal SRD5A2 promotes prostate growth through WNT5A-LEF1-IGF1 signaling in benign prostatic hyperplasia

Steroid 5-reductase type 2 (SRD5A2) is a key enzyme in androgen metabolism and a pharmacologic target in benign prostatic hyperplasia (BPH). While SRD5A2 is known to mediate stromal-epithelial interactions that influence prostate growth, the relationship between baseline SRD5A2 expression and prostate volume remains unclear. In this study, we analyzed SRD5A2 expression in human prostate tissues from the Medical Therapy of Prostatic Symptoms (MTOPS) trial and institutional biorepository cohorts. Quantitative assessments were performed and correlations were evaluated between expression level of SRD5A2, WNT5A, prostate volume, and tissue signaling profiles. SRD5A2 expression was significantly associated with total prostate and transition zone volume in both human cohorts. Stromal-specific WNT5A expression showed a strong positive correlation with SRD5A2, while neither serum nor tissue dihydrotestosterone levels correlated with SRD5A2 expression. In Srd5a2-null mice, Wnt5a expression in the prostate stroma was dependent on Srd5a2 and showed region-specific regulation. Mechanistically, SRD5A2 overexpression in human prostate stromal cells upregulated WNT5A and Lymphoid Enhancer-Binding Factor 1 (LEF1), activated insulin-like growth factor 1 (IGF1) signaling, increased proliferation, and reduced apoptosis. Conditioned media from these cells enhanced epithelial proliferation through paracrine IGF1 activity, independent of epithelial WNT signaling. This study provides the first evidence that SRD5A2 promotes prostate growth through a stromal WNT5A-LEF1-IGF1 paracrine signaling axis, functioning independently of androgen levels. These findings suggest a novel therapeutic mechanism relevant for BPH patients with resistance to conventional 5-reductase inhibitor therapy.

pathology↗

bioRxiv2024

Ectonucleotidases and Purinergic Receptors in Mouse Prostate Gland

Extracellular ATP/ADP and its metabolite adenosine are important signaling molecules that regulate cellular function by binding to P2 and P1/adenosine receptors. The kinetics of these signaling molecules are critically modulated by ectonucleotidases, enzymes that convert ATP/ADP to adenosine. Although the expression and function of these enzymes and relevant purinergic receptors in the prostate gland are not well understood, recent reports indicate impaired ATP hydrolysis activity in the aging prostate. Purinergic signaling is known for its role in inflammation, muscle contraction, pain sensation, and cell proliferation in many systems, suggesting its potential importance in normal prostate function and pathological conditions such as benign prostatic hyperplasia and prostatitis. To better understand purine-converting enzymes and purinergic receptors in the prostate, we isolated mouse prostate glands for immunofluorescent staining and microscopy imaging using specific antibodies. Our study identified a differential expression profile of purinergic enzymes and receptors in the prostate: ENTPD1 and P2x1 receptors predominantly in prostate smooth muscle cells, ENTPD2 and NT5E in prostate interstitial cells, and ALPL in prostate epithelial cells. Functionally, in addition to the P2x1-mediated prostate smooth muscle contraction induced by agonist ,{beta}-meATP, we observed an ATP{gamma}S-induced contraction force after P2x1 desensitization. This led to the identification of multiple P2Y receptors in mouse prostate smooth muscle, including P2Y1, P2Y2, and P2Y11 receptors, which potentially mediate the ATP{gamma}S-induced contraction force. These discoveries lay the foundation for further mechanistic understanding of how purinergic signaling regulates prostate function and dysfunction in both rodents and potentially humans.

physiology↗