[Expression of HIF-1α in the prostatic tissue of mice with high-fat diet-induced obesity]

To investigate the expression of hypoxia-inducible factor-1α (HIF-1α) in the prostatic tissue of mice with high-fat diet-induced obesity and to explore the effect of hypoxia on BPH in obese male mice.

We randomly divided 20 C57BL/6J male mice into two groups of equal number and fed them on a high-fat diet (HFD group) or a normal diet (control group) for 17 weeks. Then, we measured the body weight, prostate weight, prostate volume and levels of serum triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and free fatty acids (FFA) by ELISA, observed the morphology of the prostate by HE staining, calculated the area of the prostatic glandular cavity, and determined the expression of HIF-1α in the prostatic tissue by immunohistochemistry.

Compared with the controls, the mice fed on the HFD showed significant increases in the body weight (［28.94 ± 2.17］ vs ［42.55 ± 3.01］ g, P < 0.01), prostate weight (［0.05 ± 0.03］ vs ［0.13 ± 0.03］ g, P < 0.01), prostate volume (［0.05 ± 0.02］ vs ［0.14 ± 0.03］ ml, P < 0.01), and the levels of TG (［115.77 ± 25.25］ vs ［179.29 ± 65.19］ mmol/L, P = 0.022), HDL (［67.14 ± 3.10］ vs ［72.84 ± 1.91］ g/L, P < 0.01) and LDL (［44.16 ± 7.24］ vs ［66.88 ± 1.93］ g/L, P < 0.01) at 17 weeks. Histopathological examination exhibited single-layer cuboidal or columnar prostatic epithelium in the controls but an irregular epithelial structure and a larger area of the prostatic glandular cavity in the HFD group (［12 390 ± 8 587］ vs ［18 453 ± 7 311］ μm2, P < 0.01). The integrated optical density (IOD) of HIF-1α was markedly higher in the HFD group (［9.1 ± 6.9］ × 106) than in the control (［2.0 ± 3.6］ ×106) (P < 0.01). The prostate volume was positively correlated with the body fat weight (r = 0.887, P = 0.01), TG (r = 0.520, P = 0.047) and LDL (r = 0.772, P = 0.010).

Abnormal lipid metabolism may induce local hypoxia in the prostate tissue and lead to BPH in obese mice.