17β-estradiol replacement therapy induces eNOS, nNOS and estrogen receptor β in hypophysectomized rats with inflamed footpads

Nitric oxide (NO) plays a key role in inflammation. It is partly produced by three forms of NOS: eNOS of inflammatory cells, nNOS of neural cells and iNOS (inducible isoform). Estrogens can cause an anti-inflammatory effect, although it is not yet clear through which NOS isoforms. The aim of this study was to evaluate the role of the different NOS isoforms, as well as estrogen receptors (ERs) α and β, on the anti-inflammatory effects of estrogens. To avoid the influence of endogenous glucocorticoids or sexual hormones, male rats were hypophysectomized. Animals were segregated into two control groups (no-treatment control group and SHAM-operated animals) and three hypophysectomized groups (no-hormonal treatment, with estradiol-17β, or with testosterone replacement treatment). Freund's complete adjuvant (1 mg) was administered to the footpad of all animals. Measurements were made based on footpad inflammation (with a plethysmometer) such as eNOS, nNOS, iNOS and ER α and β protein expression (by immunohistochemistry principle/method) on days 1, 7 and 14. Only estradiol decreased inflammation, accompanied by increased levels of eNOS and nNOS and differential expression of ERs α and β in the inflammatory infiltrate. The higher levels of estradiol-induced eNOS and nNOS ocurred perhaps through the activation of ER β.

Effect of botulinum neurotoxin type A (BoNTA) on the morphology and viability of 3T3 murine fibroblasts

AIM

BoNTA is used in the treatment of ophthalmological disorders, muscular hyperactivity and pain. In recent years it has been described that BoNTA reduces cellular viability and induces apoptosis in prostate cells lines. Studies about the effect of BoNTA are no well known. There have been studies about the effect of BoNTA on the expression levels of collagenase in fibroblasts, but not on its morphological impact on these cells. The aim of this study was to determine the effect of BoNTA on the morphology and viability of the 3T3 fibroblast cell line.

MATERIAL AND METHODS

The 3T3 fibroblast cell line was cultured and the experimental group received 10 U BoNTA added to a 0.9% sterile saline solution in a reconstituted vial. The control group received saline solution only. Cultured cells were observed and photographed at 5, 10, 15 and 20 h. Cell viability was evaluated by means of the trypan blue test, and cell proliferation with the Proliferation Assay kit (PROMEGA).

RESULTS

The application of BoNTA to 3T3 fibroblast cells induced morphological changes, such as a loss of normal fibroblast morphology. Additionally, we observed the cytoplasmic retraction and spread phenomena. The nuclei showed other important changes with Giemsa staining.

CONCLUSION

The results indicate that BoNTA induced a loss of spindle form, increase in cytoplasmic vesicles, and the presence of nuclear vesicles (compacted chromatin surrounded by a nuclear envelope). This suggests an apoptotic process and decreased cell viability. Further studies are needed to explore the mechanisms of these alterations.

Botulinum neurotoxin type A inhibits synaptic vesicle 2 expression in breast cancer cell lines

AIM

It is known that botulinum neurotoxin type A (BoNTA) improves some kinds of cancer (e.g. prostate) and that synaptic vesicle glycoprotein 2 (SV2) is the molecular target of this neurotoxin. Besides having potential therapeutic value, this glycoprotein has recently been proposed as a molecular marker for several types of cancer. Although the mechanisms of cancer development and the improvement found with botulinum treatment are not well understood, the formation of the botulinum-SV2 complex may influence the presence and distribution of SV2 and the function of vesicles. To date, there are no reports on the possible effect of botulinum on breast cancer of unknown causes, which have a great impact on women's health. Thus we determined the presence of SV2 in three breast cancer cell lines and the alterations found with botulinum application.

MATERIALS AND METHODS

With and without adding 10 units of botulinum, SV2 protein expression was determined by optical densitometry in T47D, MDA-MB-231 and MDA-MB-453 cell lines and the distribution of SV2 was observed with immunochemistry (hematoxylin staining).

RESULTS

The SV2 protein was abundant in the cancer cells herein tested, and maximally so in T47D. In all three cancer cell lines botulinum diminished SV2 expression, which was found mostly in the cell periphery.

CONCLUSION

SV2 could be a molecular marker in breast cancer. Its expression and distribution is regulated by botulinum, suggesting an interesting control mechanism for SV2 expression and a possible alternative therapy. Further studies are needed in this sense.