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The role of thyroid hormones (THs) in development has been extensively studied, however, the specific molecular mechanisms involved are far from being clear. THs act by binding to TH nuclear receptors (TR) that act as ligand-dependent transcription factors to regulate TH-dependent gene expression. Like vertebrates, zebrafish express different isoforms of functional Tr alpha and beta, some of which can bind alternative ligands like 3,5-T2. In this study, we first analyzed the effects of exogenous T3 and 3,5-T2 exposure during embryogenesis. The percentage of affected embryos was similar to those vehicle-injected, suggesting that the early exposure to low TH levels is not sufficient to elicit effects upon the phenotype of the embryo. We then generated crispants for four isoforms of thr to learn more about the role of these receptors in early development. We found that crispant larvae from thraa and a newly identified l-thrb+, but not thrab and canonical thrb1 showed profound deleterious effects upon symmetry and laterality, suggesting early novel roles for these Tr isoforms in the body plan developmental program. Since critical events that determine cell fate start in the late gastrula, we tested if some genes that are expressed during early developmental stages could indeed be TH targets. We identify early development genes, like sox10 and eve, that were specifically over-expressed in thraa and l-thrb+ crispants, suggesting that these specific thr isoforms function as transcription repressors for these genes, while transcription of zic and ets appear to be thraa and l-thrb+-mediated, respectively. Overall, present results show that TH signaling participates in early zebrafish development and identify Tr isoform-specific mediated regulation of early gene expression.

It has been proposed that oral commensal bacteria are potential reservoirs of a wide variety of antimicrobial resistance genes (ARGs) and could be the source of pathogenic bacteria; however, there is scarce information regarding this. In this study, three common streptococci of the mitis group (S. oralis, S. sanguinis, and S. gordonii) isolated from dental plaque (DP) were screened to identify if they were frequent reservoirs of specific ARGs (blaTEM, cfxA, tetM, tetW, tetQ, ermA, ermB, and ermC). DP samples were collected from 80 adults; one part of the sample was cultured, and from the other part DNA was obtained for first screening of the three streptococci species and the ARGs of interest. Selected samples were plated and colonies were selected for molecular identification. Thirty identified species were screened for the presence of the ARGs. From those selected, all of the S. sanguinis and S. oralis carried at least three, while only 30% of S. gordonii strains carried three or more. The most prevalent were tetM in 73%, and blaTEM and tetW both in 66.6%. On the other hand, ermA and cfxA were not present. Oral streptococci from the mitis group could be considered frequent reservoirs of specifically tetM, blaTEM, and tetW. In contrast, these three species appear not to be reservoirs of ermA and cfxA.

Abstract Antimicrobial resistance is a global public health problem. Root canal microbiota associated with apical periodontitis represents a well-known reservoir of antimicrobial resistance genes (ARGs). However, the effect of type 2 diabetes mellitus (T2DM) in this reservoir is unknown. This study aimed to establish if root canal microbiota associated with apical periodontitis in T2DM patients is an augmented reservoir by identifying the prevalence of nine common ARGs and comparing it with the prevalence in nondiabetic patients. Methodology This cross-sectional study included two groups: A T2DM group conformed of 20 patients with at least ten years of living with T2DM and a control group of 30 nondiabetic participants. Premolar or molar teeth with pulp necrosis and apical periodontitis were included. A sample was collected from each root canal before endodontic treatment. DNA was extracted, and ARGs were identified by polymerase chain reaction. Results tetW and tetM genes were the most frequent (93.3 and 91.6%, respectively), while ermA was the least frequent (8.3%) in the total population. The distribution of the ARGs was similar in both groups, but a significant difference (p

Objective: This investigation aimed to detect coincidences in the antimicrobial resistance genes (ARG) profiles between members of a group living in a household and to compare them between other groups in order to establish if an exchange of ARG occurs and if dental plaque microbiota can be considered as a source and reservoir of ARG that can be shared between humans and pets. Methods: One hundred sixty dental plaque samples were obtained from four groups: Shelter dogs group (n = 20), adult pet owners and dogs group (AD group, n = 40), adult pet owners, children and dogs group (ACD group, n = 60), and adult non-pet owners and children group (AC group, n = 40). DNA was obtained, and specific primers with polymerase chain reaction for ARG detection were used. Results: The AD group exhibited the most coincidences in their ARG profiles, 14 (70%) of the 20 profiles coincided in 100% followed by the ACD group with 9 (45%) coincidences. While the AC group was the less coincident group, only 7 (35%) of the 20 profiles coincided. tetM was the most prevalent with 53.1%, followed by tetQ with 52.5% and cfxA with 51.2%, while the less prevalent were tetW with 31.8%, blaTEM-1 with 27.5%, and ermC with 18.7%. Conclusion: Dental plaque microbiota can be considered as a source and reservoir of ARG that can be shared between humans and dogs living in a household. The dogs seem to play an important role in the transference of ARG, and the children appear to be the most affected by carrying the most significant number of ARG.

The estrogenic receptor beta (ERβ) protects against carcinogenesis by stimulating apoptosis. Bisphenol A (BPA) is related to promoting cancer, and naringenin has chemoprotective activities both can bind to ERβ. Naringenin in the colon is metabolized by the microbiota. Cancer involves genetic and epigenetic mechanisms, including miRNAs. The objective of the present study was to evaluate the co-exposure effect of colonic in vitro fermented extract of naringenin (FEN) and BPA, to elucidate molecular effects in HT-29 colon cancer cell line. For this, we quantified genes related to the p53 signaling pathway as well as ERβ, miR-200c, and miR-141. As an important result, naringenin (IC50 250 µM) and FEN (IC50 37%) promoted intrinsic pathways of apoptosis through phosphatase and tensin homolog (PTEN) (+2.70, +1.72-fold, respectively) and CASP9 (+3.99, +2.03-fold, respectively) expression. BPA decreased the expression of PTEN (−3.46-fold) gene regulated by miR-200. We suggest that once co-exposed, cells undergo a greater stress forcing them to mediate other extrinsic apoptosis mechanisms associated with death domain FASL. In turn, these findings are related to the increase of ERβ (5.3-fold with naringenin and 13.67-fold with FEN) gene expression, important in the inhibition of carcinogenic development.