p27kip1 overexpression regulates IL-1ß in the microenvironment of stem cells and eutopic endometriosis co-cultures.

Endometriosis is a gynecological benign chronic disease defined as the growth of endometrial glands and stroma in extra-uterine sites, most commonly implanted over visceral and peritoneal surfaces within the female pelvis causing inflammatory lesions. It affects around 10% of the female population and is often accompanied by chronic pelvic pain, adhesion formation and infertility. Therefore, endometriosis could be considered a "social disease", since it affects the quality of life, reproductivity and also has a socio-economic impact. The expression of cell cycle and inflammatory proteins is modified in the endometriotic tissues. Immunostaining of glandular and stromal cells in endometrial biopsies obtained from patients with endometriosis compared with those of healthy control demonstrated that endometriotic tissues have lower levels of p27kip1 protein. Endometriosis endometrial cells cultures have also lower levels of p27kip1 compared to health endometrial cells cultures and restore the cell cycle balance when transduced with an adenoviral vector carring the p27kip1 coding gene (Adp27EGFP). The low levels of p27kip1 are related to the S phase in the cell cycle, whereas higher levels lead to a G1 cell cycle arrest. The inflammatory cytokine IL-1ß was recently identified as another key protein in the endometriosis proliferation. This cytokine has elevated levels during the proliferative and secretory phases of the menstrual cycle. In endometriosis endometrial cells cultures the IL-1ß stimulates the production of IL-6 and IL-8, increasing the cell proliferation and reducing the apoptosis and Bax expression in these cells. According to these remarks, this work aims to evaluate the inflammatory effects in vitro, but more next to what happens in a woman's body, associating endometrial cells with stem cells, thus mimicking the endometrial microenvironment, with gene therapy using Adp27, notoriously known as controller cell cycle, apoptosis and potent modulator of VEGF expression.

p27kip1 overexpression regulates VEGF expression, cell proliferation and apoptosis in cell culture from eutopic endometrium of women with endometriosis.

We hypothesized that p27(kip1) overexpression can regulate endometriosis cell proliferation, apoptosis and vascular endothelial growth factor (VEGF) expression in the endometrium. The overexpression of p27(kip1) was obtained by transduction of p27(kip1) in primary cultures of endometrium obtained from women with endometriosis tissue with gene therapy technology. First generation bicistronic adenovirus: AdCMVhp27IRESEGFP (Adp27) and AdCMVNull (AdNull) were engineered in order to induce p27(kip1) expression in endometrial cells primary culture. The effect of p27(kip1) overexpression was elucidated through the cell proliferation evaluation and the expression of the cell cycle-related proteins p16, p21, p27, and p53. Cell cycle and apoptosis in endometrial cells from women with and without endometriosis were also evaluated. The VEGF levels were evaluated 1 and 7 days after transduction. The experiments were performed using Immunofluorescence stainings and flow cytometry technique. The cell proliferation statistically diminished markedly following p27(kip1) overexpression in the endometriosis group. This process was accompanied, however, by a statistically significant modulation of the cell cycle-related proteins p16, p21, p27 and p53 markedly increase following p27(kip1) overexpression in the endometriosis group (p < 0.001) and an increase in apoptotic cells was observed. In the endometriosis group, significant downregulation of VEGF expression was observed 7 days after p27(kip1) overexpression, attaining levels strikingly similar to those observed in the control endometrial cells. The findings of this study showed a link between the cell cycle control protein (p27(kip1)) and angiogenesis (VEGF). Our results, also reinforces the background of endometrial dysfunction as part of the origin of endometriosis. We believe that better knowledge of endometrium milieu and the establishment of the link between different, previously describe, altered pathways in this tissue can facilitate future genetic cell therapy.

Different responses of the GlnB and GlnZ proteins upon in vitro uridylylation by the Azospirillum brasilense GlnD protein.

Azospirillum brasilense is a diazotroph found in association with important agricultural crops. In this organism, the regulation of nitrogen fixation by ammonium ions involves several proteins including the uridylyltransferase/uridylyl-removing enzyme, GlnD, which reversibly uridylylates the two PII proteins, GlnB and GlnZ, in response to the concentration of ammonium ions. In the present study, the uridylylation/deuridylylation cycle of A. brasilense GlnB and GlnZ proteins by GlnD was reconstituted in vitro using the purified proteins. The uridylylation assay was analyzed using non-denaturing polyacrylamide gel electrophoresis and fluorescent protein detection. Our results show that the purified A. brasilense GlnB and GlnZ proteins were uridylylated by the purified A. brasilense GlnD protein in a process dependent on ATP and 2-oxoglutarate. The dependence on ATP for uridylylation was similar for both proteins. On the other hand, at micromolar concentration of 2-oxoglutarate (up to 100 microM), GlnB uridylylation was almost twice that of GlnZ, an effect that was not observed at higher concentrations of 2-oxoglutarate (up to 10 mM). Glutamine inhibited uridylylation and stimulated deuridylylation of both GlnB and GlnZ. However, glutamine seemed to inhibit GlnZ uridylylation more efficiently. Our results suggest that the differences in the uridylylation pattern of GlnB and GlnZ might be important for fine-tuning of the signaling pathway of cellular nitrogen status in A. brasilense.

Different responses of the GlnB and GlnZ proteins upon in vitro uridylylation by the Azospirillum brasilense GlnD protein

Azospirillum brasilense is a diazotroph found in association with important agricultural crops. In this organism, the regulation of nitrogen fixation by ammonium ions involves several proteins including the uridylyltransferase/uridylyl-removing enzyme, GlnD, which reversibly uridylylates the two PII proteins, GlnB and GlnZ, in response to the concentration of ammonium ions. In the present study, the uridylylation/deuridylylation cycle of A. brasilense GlnB and GlnZ proteins by GlnD was reconstituted in vitro using the purified proteins. The uridylylation assay was analyzed using non-denaturing polyacrylamide gel electrophoresis and fluorescent protein detection. Our results show that the purified A. brasilense GlnB and GlnZ proteins were uridylylated by the purified A. brasilense GlnD protein in a process dependent on ATP and 2-oxoglutarate. The dependence on ATP for uridylylation was similar for both proteins. On the other hand, at micromolar concentration of 2-oxoglutarate (up to 100 µM), GlnB uridylylation was almost twice that of GlnZ, an effect that was not observed at higher concentrations of 2-oxoglutarate (up to 10 mM). Glutamine inhibited uridylylation and stimulated deuridylylation of both GlnB and GlnZ. However, glutamine seemed to inhibit GlnZ uridylylation more efficiently. Our results suggest that the differences in the uridylylation pattern of GlnB and GlnZ might be important for fine-tuning of the signaling pathway of cellular nitrogen status in A. brasilense.