Angiogenic and Tissue Remodeling Factors in the Prostate of Elderly Rats Submitted to Hormonal Replacement

Differential tempol effects in prostatic cancer: angiogenesis and short- and long-term treatments

Prostate cancer (PCa) is the second cause of cancer death among men worldwide. Several processes are involved in the development and progression of PCa such as angiogenesis, inflammation and oxidative stress. The present study investigated the effect of short- or long-term Tempol treatment at different stages of prostate adenocarcinoma progression, focusing on angiogenic, proliferative, and stromal remodeling processes in TRAMP mice. The dorsolateral lobe of the prostate of TRAMP mice were evaluated at two different stages of PCa progression; early and late stages. Early stage was again divided into, short- or long-term. 50 mg/kg Tempol dose was administered orally. The results demonstrated that Tempol mitigated the prostate histopathological lesion progressions in the TRAMP mice in all treated groups. However, Tempol increased molecules involved in the angiogenic process such as CD31 and VEGFR2 relative frequencies, particularly in long-term treatment. In addition, Tempol upregulated molecule levels involved in angiogenesis and stromal remodeling process VEGF, TGF-β1, VE-cadherin and vimentin, particularly, in T8-16 group. Thus, it was concluded that Tempol treatment delayed prostatic lesion progression in the dorsolateral lobe of the TRAMP mice. However, Tempol also led to pro-angiogenic effects and glandular stromal microenvironment imbalance, especially, in the long-term treatment.

Supraphysiological testosterone supplementation improves granulation tissue maturation through angiogenesis in the early phase of a cutaneous wound healing model in rats

OBJECTIVE

The aim of this study was to evaluate the effects of both testosterone depletion and supraphysiological testosterone supplementation in the early phase of an animal cutaneous wound healing model in comparison with the physiological hormonal condition.

MATERIAL AND METHODS

Forty rats were distributed into the following four groups: Control, Orchiectomy (OCX), Durateston (Dura) and OCX+Dura. On day 1, the testicles were removed (OCX group) and the rats (Dura group) received a supraphysiological dose (250 mg/kg) of exogenous testosterone weekly. After 15 days a full-thickness excisional skin wound was created in all animals, which was healed by the second intention for 7 days. On day 22, the rats were euthanatized and the wounds were harvested for histopathological evaluation, immunohistochemistry analyses and multiplex immunoassay. One-way ANOVA and post-hoc Tukey tests were performed.

RESULTS

It was found that the supraphysiological testosterone level increased extracellular matrix deposition, promoted higher blood vessel formation and reduced wound contraction (p < 0.05). Additionally, it also stimulated PCNA-positive fibroblasts and KGF-positive cells (p < 0.05), while orchiectomy reduced the expression of IL-6 and TNF-α and increased VEGF and PDGF (p < 0.05) .

CONCLUSION

In conclusion, the results provide evidence that supraphysiological testosterone supplementation plays a positive role in the early phase of cutaneous wound healing, thus improving granulation tissue maturation through the enhancement of angiogenesis.

The role of testosterone in mu-opioid receptor expression in the trigeminal ganglia of opioid-tolerant rats

Although tolerance serves as a major limitation in the long-term clinical use of opioids in patients with chronic severe pain, mechanisms of opioid tolerance are poorly understood. In this study, a morphine tolerance model was established by subcutaneously injecting male rats with morphine (10 mg/kg) twice a day for 10 consecutive days. In addition, a subset of morphine-tolerant rats underwent testosterone replacement therapy. The levels of mu-opioid receptor (MOR) mRNA and protein in the trigeminal ganglia (TGs) of morphine-tolerant versus control rats and of morphine-tolerant rats with vs. without testosterone replacement therapy were measured. We found that testosterone levels were significantly lower in morphine-tolerant rats than in the controls (1.248 ± 0.231 ng/ml vs. 2.223 ± 0.153 ng/ ml, respectively; p = 0.008). Furthermore, chronic morphine exposure led to a downregulation in the levels of MOR mRNA to 79.3%, and of MOR protein to 68.9%. Testosterone replacement therapy restored MOR mRNA and protein levels specifically in rats who had developed a tolerance to morphine, thereby suggesting a potential role of testosterone in the opioid-receptor response to chronic morphine exposure. In summary, our study provides evidence for the involvement of testosterone in the proper regulation of the peripheral MOR system in rats following prolonged morphine exposure. We also suggest that analgesic therapeutic measures should take into account the testosterone levels of patients who have built up a tolerance to morphine.

A jaboticaba extract prevents prostatic damage associated with aging and high-fat diet intake

Jaboticaba extract prevented the prostatic lesion development in aging and/or overweight mice, mainly interfering in cell proliferation, hormonal and angiogenesis pathways.

Characterization a model of prostatic diseases and obstructive voiding induced by sex hormone imbalance in the Wistar and Noble rats

Background

Chronic nonbacterial prostatitis associated with lower urinary tract symptoms (LUTS) is a prevalent condition in men. One potential pathophysiological factor is change in sex hormone, testosterone and estrogen, balance. Inflammation, cancer and obstructive voiding has been induced in the Noble rat strain by altering levels of sex hormones. We evaluated if imbalance of sex hormones could induce comparable diseases also in a less estrogen sensitive Wistar strain rats.

Methods

Subcutaneous testosterone (830 µg/day) and 17β-estradiol (83 µg/day) hormone pellets were used in male Wistar and Noble strain rats to induce prostatic diseases. The rats were followed for 13 and 18 weeks. Urodynamical measurements were performed at the end of the study under anesthesia. Prostates were collected for further histological analysis. A panel of cytokines were measured from collected serum samples.

Results

Noble rats exhibited stromal and glandular inflammation after 13 weeks that progressed into more severe forms after 18 weeks of hormonal treatment. CD68-positive macrophages were observed in the stromal areas and inside the inflamed acini. CD163-positive macrophages were present in the stromal compartment but absent inside inflammatory foci or prostate acini. Thirteen-week hormonal treatment in Noble rats induced obstructive voiding, which progressed to urinary retention after 18-weeks treatment. In the Wistar rats 18-week treatment was comparable to the 13-week-treated Noble rats judged by progression of prostatic inflammation, being also evident for obstructive voiding. Incidence of PIN-like lesions and carcinomas in the periurethal area in Noble rats were high (100%) but lower (57%) and with smaller lesions in Wistar rats. Serum cytokines leptin, CCL5, and VEGF concentrations showed a decrease in the hormone-treated rats compared to placebo-treated rats.

Conclusions

Prostate inflammation and obstructive voiding developed also in the Wistar rats but more slowly than in Noble rats. Male non-castrated Wistar strain rats may thus be suitable to use in studies of pathophysiology and hormone-dependent prostate inflammation and obstructive voiding.

In touch with your feminine side: how oestrogen metabolism impacts prostate cancer

Prostate cancer is the primary cancer in males, with increasing global incidence rates making this malignancy a significant healthcare burden. Androgens not only promote normal prostate maturity but also influence the development and progression of prostate cancer. Intriguingly, evidence now suggests endogenous and exogenous oestrogens, in the form of phytoestrogens, may be equally as relevant as androgens in prostate cancer growth. The prostate gland has the molecular mechanisms, catalysed by steroid sulphatase (STS), to unconjugate and utilise circulating oestrogens. Furthermore, prostate tissue also expresses enzymes essential for local oestrogen metabolism, including aromatase (CYP19A1) and 3β- and 17β-hydroxysteroid dehydrogenases. Increased expression of these enzymes in malignant prostate tissue compared with normal prostate indicates that oestrogen synthesis is favoured in malignancy and thus may influence tumour progression. In contrast to previous reviews, here we comprehensively explore the epidemiological and scientific evidence on how oestrogens impact prostate cancer, particularly focusing on pre-receptor oestrogen metabolism and subsequent molecular action. We analyse how molecular mechanisms and metabolic pathways involved in androgen and oestrogen synthesis intertwine to alter prostate tissue. Furthermore, we speculate on whether oestrogen receptor status in the prostate affects progression of this malignancy.

Prostatic angiogenic responses in late life: antiangiogenic therapy influences and relation with the glandular microenvironment in the transgenic adenocarcinoma of mouse prostate (TRAMP) model

BACKGROUND

Aging is considered one of the main predisposing factors for the development of prostate malignancies. Angiogenesis is fundamental for tumor growth and its inhibition represents a promising therapeutic approach in cancer treatment. Thus, we sought to determine angiogenic responses and the effects of antiangiogenic therapy in the mouse prostate during late life, comparing these findings with the prostatic microenvironment in the Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) model.

METHODS

Male mice (52 week-old FVB) were submitted to treatments with SU5416 (6 mg/kg; i.p.) and/or TNP-470 (15 mg/kg; s.c.). Finasteride was administered (20 mg/kg; s.c.), alone or in association to both inhibitors. The dorsolateral prostate was collected for VEGF, HIF-1α, FGF-2 and endostatin immunohistochemical and Western Blotting analyses and for microvessel density (MVD) count.

RESULTS

Senescence led to increased MVD and VEGF, HIF-1α and FGF-2 protein levels in the prostatic microenvironment, similarly to what was observed in TRAMP mice prostate. The angiogenic process was impaired in all the treated groups, demonstrating significantly decreased MVD. Antiangiogenic and/or finasteride treatments resulted in decreased VEGF and HIF-1α levels, especially following TNP-470 administration, either alone or associated to SU5416. The combination of these agents resulted in increased endostatin levels, regardless of the presence of finasteride.

CONCLUSIONS

Prostatic angiogenesis stimulation during senescence favored the development of neoplastic lesions, considering the pro-angiogenic microenvironment as a common aspect also observed during cancer progression in TRAMP mice. The combined antiangiogenic therapy was more efficient, leading to enhanced imbalance towards angiogenic inhibition in the organ. Finally, finasteride administration might secondarily upregulate the expression of pro-angiogenic factors, pointing to the harmful effects of this therapy.