Natália Torres

This study analyzed the relationship between mindfulness and variables considered relevant for teacher–student interactions: teacher burnout, general stress, anxiety, depression, and quality of life. We hypothesized that mindfulness would relate negatively with mental health variables and positively with quality of life. We also explored which specific aspects of mindfulness would predict burnout, depression, anxiety, stress, and quality of life. Given the results of regression analyses, mediation models were performed to explore the mechanisms through which different facets of mindfulness affect quality of life. As predicted, the correlation analysis showed that mindfulness and its dimensions were positively associated with the quality of life of the teachers and burnout dimension of personal fulfillment and negatively associated with anxiety, depression, and stress (considering FFMQ total score and most of its dimensions). Consistently, regression analysis showed that the overall level of mindfulness, after controlling for the grade level at which the teacher works, showed significant associations with the level of personal fulfillment, depression, anxiety, stress, and quality of life. The results of the mediation analyses showed that the ability not to judge ourselves was associated with fewer symptoms of depression and stress and, through these pathways, positively affected quality of life. On the other hand, the ability not to react favored quality of life by reducing anxiety and stress. Finally, acting with awareness was the only facet of mindfulness that favored quality of life, affecting one of the dimensions of burnout.

Delaying replicative senescence and extending lifespan of human mesenchymal stromal cells (MSCs) may enhance their potential for tissue engineering and cell based therapies. Accumulating evidence suggests that inhibitors of the mTOR signaling pathway, such as rapamycin, constitute promising pharmacological agents to retard senescence and extend stemness properties of various progenitor cell types. Here, we investigated whether the ability of rapamycin to postpone replicative senescence varies among bone marrow MSC samples (BM-MSCs) derived from different healthy donors, and explored the molecular mechanisms that drive rapamycin-mediated lifespan increment. BM-MSCs at early passages were serially passaged either in absence or continuous presence of rapamycin and the number of cell population doublings until growth arrest was measured. The inhibition of mTOR signaling was assessed by the phosphorylation status of the downstream target RPS6. The expression levels of several senescence and pluripotency markers at early and late/senescent passages were analyzed by RT-qPCR, flow cytometry and western blot. We found that the lifespan extension in response to the continuous rapamycin treatment was highly variable among samples, but effective in most BM-MSCs. Despite all rapamycin-treated cells secreted significantly reduced levels of IL6, a major SASP cytokine, and expressed significantly higher levels of the pluripotency marker NANOG, the expression patterns of these markers were not correlated with the rapamycin-mediated increase in lifespan. Interestingly, rapamycin-mediated life-span extension was significantly associated only with repression of p16^INK4A protein accumulation. Taken together, our results suggest that some, but not all, BM-MSC samples would benefit from using rapamycin to postpone replicative arrest and reinforce a critical role of p16^INK4A protein downregulation in this process.

The cellular function in endometriosis lesions depends on a highly estrogenic milieu. Lately, it is becoming evident that, besides the circulating levels of estrogens, the balance of synthesis versus inactivation (metabolism) of estrogens by intralesion steroid-metabolizing enzymes also determines the local net estrogen availability. In order to extend the knowledge of the role of estrogen-metabolizing enzymes in endometriosis, we investigated the gene and protein expression of a key uridine diphospho-glucuronosyltransferase (UGT) for estrogen glucuronidation, UGT1A1, in eutopic endometrial samples obtained from nonaffected and endometriosis-affected women and also from endometriotic lesions. Although UGT1A1 messenger RNA (mRNA) expression was detected at similar frequencies in endometriotic lesions and in eutopic endometrial samples, the levels of mRNA expression were greater in deep-infiltrating endometriotic lesions and in non-deep-infiltrating lesions when compared with either control endometrium or eutopic endometrium from women with endometriosis. Overall, we observed that protein expression of UGT1A1 was significantly more frequent in samples from endometriotic lesions in comparison with endometria. In addition, expression of UGT1A1 protein was greater in deep-infiltrating than in non-deep-infiltrating endometriotic lesions. We suggest that the finding of increased expression of UGT1A1 in lesions versus endometria might be related to impairment of regulatory mechanisms, in response to a highly estrogenic milieu, and that this enzyme may be a new target for therapy.

The estrogen-metabolizing activities of cytochrome P450 (CYP) enzymes have been implicated in endometriosis. However, their regulation in various sources of endometrial tissue under different hormonal conditions has not been clarified. Our objective was to study the hormone regulation of a specific CYP enzyme, namely CYP3A4, in control (n = 15) and endometriosis patients (n = 42). To this end, we evaluated mRNA expression (using real-time PCR) of CYP3A4 in tissue samples classified according to the phase of menstrual cycle at which they were obtained as confirmed by the related circulating hormone levels. Protein expression was also evaluated by Western Blot. In order to further investigate the hormonal regulation of CYP3A4, stromal cells from ovarian endometriotic lesions were cultured with the prevailing hormones of the distinct phases of the menstrual cycle. We observed that all control and endometriosis tissues express CYP3A4. Nevertheless, changes in CYP3A4 gene expression related to cycle phase were only seen in the control eutopic endometrium and not in samples from endometriosis patients, with an increase in the luteal phase. Stromal cells isolated from ovarian endometriotic lesions expressed CYP3A4 and their exposure to luteal phase-mimicking hormones (estradiol + progesterone) reduced CYP3A4 mRNA in parallel with a diminished expression of the corresponding receptors, estrogen receptor alpha and progesterone receptor. Our findings suggest that steroid hormones are able to regulate CYP3A4 mRNA expression, although the circulating levels of these hormones can only regulate control endometrium and not endometriosis tissues, probably because of dysregulated local steroid concentration in these latter samples.

Endometriosis is an estrogen-dependent disease affecting up to 10% of all premenopausal women. There is evidence that different endometriosis sites show distinct local estrogen concentration, which, in turn, might be due to a unique local estrogen metabolism. We aimed to investigate whether there was a site-specific regulation of selected enzymes responsible for the oxidative metabolism of estrogens in biopsy samples and endometrial and endometriotic stromal cells. Cytochrome P450 (CYP) 1A1 and CYP1B1 mRNA and protein expressions in deep-infiltrating (rectal, retossigmoidal, and uterossacral) lesions, superficial (ovarian and peritoneal) lesions, and eutopic and healthy (control) endometrium were evaluated by real-time PCR and western blot. Using a cross-sectional study design with 58 premenopausal women who were not under hormonal treatment, we were able to identify an overall increased CYP1A1 and CYP1B1 mRNA expression in superficial lesions compared with the healthy endometrium. CYP1A1 mRNA expression in superficial lesions was also greater than in the eutopic endometrium. Interestingly, we found a similar pattern of CYP1A1 and CYP1B1 expression in in vitro stromal cells isolated from ovarian lesions (n=3) when compared with stromal cells isolated from either rectum lesions or eutopic endometrium. In contradiction, there was an increased half-life of estradiol (measured by HPLC-MS-MS) in ovarian endometriotic stromal cells compared with paired eutopic stromal endometrial cells. Our results indicate that there is a site-dependent regulation of CYP1A1 and CYP1B1 in ovarian/peritoneal lesions and ovarian endometriotic stromal cells, whereas a slower metabolism is taking place in these cells.

Small non-coding regulatory RNAs control cellular functions at the transcriptional and post-transcriptional levels. Oral squamous cell carcinoma is among the leading cancers in the world and the presence of cervical lymph node metastases is currently its strongest prognostic factor. In this work we aimed at finding small RNAs expressed in oral squamous cell carcinoma that could be associated with the presence of lymph node metastasis. Small RNA libraries from metastatic and non-metastatic oral squamous cell carcinomas were sequenced for the identification and quantification of known small RNAs. Selected markers were validated in plasma samples. Additionally, we used in silico analysis to investigate possible new molecules, not previously described, involved in the metastatic process. Global expression patterns were not associated with cervical metastases. MiR-21, miR-203 and miR-205 were highly expressed throughout samples, in agreement with their role in epithelial cell biology, but disagreeing with studies correlating these molecules with cancer invasion. Eighteen microRNAs, but no other small RNA class, varied consistently between metastatic and non-metastatic samples. Nine of these microRNAs had been previously detected in human plasma, eight of which presented consistent results between tissue and plasma samples. MiR-31 and miR-130b, known to inhibit several steps in the metastatic process, were over-expressed in non-metastatic samples and the expression of miR-130b was confirmed in plasma of patients showing no metastasis. MiR-181 and miR-296 were detected in metastatic tumors and the expression of miR-296 was confirmed in plasma of patients presenting metastasis. A novel microRNA-like molecule was also associated with non-metastatic samples, potentially targeting cell-signaling mechanisms. We corroborate literature data on the role of small RNAs in cancer metastasis and suggest the detection of microRNAs as a tool that may assist in the evaluation of oral squamous cell carcinoma metastatic potential.

The implication of post-transcriptional regulation by microRNAs in molecular mechanisms underlying cancer disease is well documented. However, their interference at the cellular level is not fully explored. Functional in vitro studies are fundamental for the comprehension of their role; nevertheless results are highly dependable on the adopted cellular model. Next generation small RNA transcriptomic sequencing data of a tumor cell line and keratinocytes derived from primary culture was generated in order to characterize the microRNA content of these systems, thus helping in their understanding. Both constitute cell models for functional studies of microRNAs in head and neck squamous cell carcinoma (HNSCC), a smoking-related cancer. Known microRNAs were quantified and analyzed in the context of gene regulation. New microRNAs were investigated using similarity and structural search, ab initio classification, and prediction of the location of mature microRNAs within would-be precursor sequences. Results were compared with small RNA transcriptomic sequences from HNSCC samples in order to access the applicability of these cell models for cancer phenotype comprehension and for novel molecule discovery.