Effect of combined hormonal and insulin therapy on the steroid hormone receptors and growth factors signalling in diabetic mice prostate

Abstract

Diabetes causes harmful effects on prostatic morphology and function. However, there still are doubts about the occurrence of various diseases in the prostate, as well as abnormal angiogenesis in relation to diabetes. Thus, the aim of this study was to correlate and quantify the level of the steroid hormone receptors and the angiogenic and antiangiogenic factors in non-obese diabetic mice (Nod) after combined hormonal and insulin therapy. Sixty mice were divided into six groups after 20 days of diabetes: the control group received 0.9% NaCl, as did the diabetic group. The diabetic-insulin group received insulin, the diabetic-testosterone group received testosterone cypionate, the diabetic-oestrogen group received 17β-oestradiol, and the diabetic-insulin-testosterone-oestrogen group received insulin, testosterone and oestrogen simultaneously. After 20 days, the ventral lobe was processed for immunocytochemical and hormonal analyses. The results showed that the lowest serum testosterone and androgen receptor levels were found in the diabetic group and the highest testosterone and androgen receptor levels in the diabetic-insulin-testosterone-oestrogen group. The serum oestrogen level and its receptor showed changes opposite to those of testosterone and its receptor. The endostatin reactivity was mainly decreased in diabetic mice. The greatest IGFR-1 and VEGF reactivities occurred in diabetic mice. Thus, diabetes led to the prostatic hormonal imbalance, affecting molecular dynamics and angiogenesis in this organ. Combined insulin and steroid hormone therapy partially restored the hormonal and angiogenic imbalance caused by diabetes.

Figure 1

Immunohistochemistry of the ventral prostate from the Control (a, b, c, d, e, f), Diabetic (g, h, i, j, k, l) and Diabetic-Insulin (m, n, o, p, q, r) groups. (a) Intense AR immunoreactivity (arrows) in the nuclei of secretory epithelial cells and weak in stromal cells. (b) Weak αER immunoreactivity in the periacinar prostatic stroma (arrows). (c) Intense βER immunoreactivity (arrows) in the nuclei of epithelial cells. (d) Weak IGFR-1 immunoreactivity in the prostatic stroma (arrow). (e) Intense Endostatin immunoreactivity in prostatic stroma (arrows) and blood vessels (asterisks). (f) Weak VEGF immunoreactivity in secretory epithelium (arrows) and blood vessels (asterisks). (g) Weak AR immunoreactivity (arrows) in secretory epithelial cells and moderate in stromal cells. (h) Intense αER immunoreactivity (arrows) in the glandular stroma and secretory epithelium. (i) Weak βER immunoreactivity (arrows) in the nuclei of the epithelial cells. (j) Intense IGFR-1 immunoreactivity (arrow) in the glandular stroma. (k) Weak Endostatin immunoreactivity in prostatic stroma (arrows) and blood vessels (asterisks). (l) Intense VEGF immunoreactivity in secretory epithelium (arrows) and blood vessels (asterisks). (m) Weak AR immunoreactivity (arrows) in secretory epithelial cells and moderate in stromal cells. (n) Intense αER immunoreactivity (arrows) in the glandular stroma and moderate in secretory epithelium. (o) Weak βER immunoreactivity (arrows) in the nuclei of the epithelial cells. (p) Intense IGFR-1 immunoreactivity (arrow) in the glandular stroma. (q) Weak Endostatin immunoreactivity in prostatic stroma (arrows) and blood vessels (asterisk). (r) Intense VEGF immunoreactivity in secretory epithelium (arrows) and blood vessels (asterisks). In a–r, L, lumen; Ep, secretory epithelium; St, stroma.

Figure 2

Immunohistochemistry of the ventral prostate from the Diabetic-Testosterone (a, b, c, d, e, f), Diabetic-Oestrogen (g, h, i, j, k, l) and Diabetic-Insulin–Testosterone–Oestrogen (m, n, o, p, q, r) groups. (a) Moderate AR immunostaining (arrows) in secretory epithelial cells and intense in stromal cells. (b) Moderate αER immunoreactivity (arrows) in prostatic stroma and secretory epithelium. (c) Moderate βER immunoreactivity (arrows) in secretory epithelial cells. (d) Intense IGFR-1 immunoreactivity (arrow) in the prostatic stroma. (e) Moderate Endostatin immunoreactivity in prostatic stroma (arrows) and blood vessels (asterisks). (f) Moderate VEGF immunoreactivity in secretory epithelium (arrows) and blood vessels (asterisks). (g) Moderate AR immunoreactivity (arrows) in secretory epithelial cells and intense in stromal cells. (h) Intense αER immunoreactivity (arrows) in the glandular stroma and moderate in secretory epithelium. (i) Weak βER immunoreactivity (arrows) in the nuclei of the epithelial cells. (j) Intense IGFR-1 immunoreactivity (arrow) in the glandular stroma. (k) Moderate Endostatin immunoreactivity in prostatic stroma (arrows) and blood vessels (asterisk). (l) Intense VEGF immunoreactivity in secretory epithelium (arrows) and blood vessels (asterisks). (m) Intense AR immunostaining (arrows) in secretory epithelial cells and weak in stromal cells. (n) Moderate αER immunoreactivity (arrows) in the prostatic stroma. (o) Intense βER immunoreactivity (arrows) in the nuclei of the epithelial cells. (p) Moderate IGFR-1 immunoreactivity (arrow) in the prostatic stroma. (q) Intense Endostatin immunoreactivity in prostatic stroma (arrows) and blood vessels (asterisks). (r) Weak VEGF immunoreactivity in secretory epithelium (arrows) and blood vessels (asterisks). In a–r, L, lumen; Ep, secretory epithelium; St, stroma.

Figure 3

Representative Western Blotting and semiquantitative determination for AR, αER, βER, IGFR-1, Endostatin and VEGF proteins of the prostate ventral lobe extracts in the six experimental groups. The protein levels were identified in the blots. β-Actin was used as the endogenous control. Data were expressed as the mean ± standard deviation (n = 10).