Clinical Application Value of Pharmacokinetic Parameters of Vancomycin in Children Treated in the Pediatric Intensive Care Unit.

Objective: To explore the efficacy and safety of vancomycin as measured by pharmacokinetic/pharmacodynamic parameters in children with severe infection in the Pediatric Intensive Care Unit (PICU) and to determine the appropriate threshold for avoiding nephrotoxicity. Methods: The medical records of hospitalized children with severe infection treated with vancomycin in the PICU of a tertiary pediatric hospital from September 2018 to January 2021 were retrospectively collected. Univariate analysis was used to assess the correlation between vancomycin pharmacokinetic/pharmacodynamic parameters and therapeutic efficacy or vancomycin-related nephrotoxicity. Binary logistic regression was used to analyze the risk factors for vancomycin-related nephrotoxicity. The vancomycin area under the concentration-time curve over 24 h (AUC0-24) threshold was determined by receiver operating characteristic (ROC) curve analysis. Results: One hundred and 10 patients were included in this study. Seventy-six patients (69.1%) exhibited clinically effective response, while the rest exhibited clinically ineffective response. There were no significant differences in APACHE II score, steady-state trough concentration, peak concentration or AUC0-24 of vancomycin between the effective and ineffective groups. Among the 110 patients, vancomycin-related nephrotoxicity occurred in 15 patients (13.6%). Multivariate analysis showed that vancomycin treatment duration, trough concentration, and AUC0-24 were risk factors for vancomycin-related nephrotoxicity. The ROC curve indicated that AUC0-24 < 537.18 mg.h/L was a suitable cutoff point for predicting vancomycin-related nephrotoxicity. Conclusion: No significant correlations were found between the trough concentration or AUC0-24 of vancomycin and therapeutic efficacy when the daily dose of vancomycin was approximately 40 mg/kg d, while the trough concentration and AUC0-24 were both closely related to vancomycin-related nephrotoxicity. The combination of AUC0-24 and trough concentration for therapeutic drug monitoring may reduce the risk of nephrotoxicity.

Antenatal exposure to betamethasone induces placental 11ß-hydroxysteroid dehydrogenase type 2 expression and the adult metabolic disorders in mice.

Antenatal overexposure to glucocorticoids causes fetal intrauterine growth restriction (IUGR) and adult metabolic disorders. 11ß-hydroxysteroid dehydrogenase (11ß-HSD) 1 and 2 are key enzymes for glucocorticoid metabolism, however, the detailed effects of antenatal overexposure to glucocorticoids on placental 11ß-HSD1 and 2 expression and adult metabolic disorders remain obscure. Here, we report that, in placenta 11ß-HSD1 is diffusely localized, whereas 11ß-HSD2 is specifically expressed in labyrinthine layer. Exposure of pregnant dams to betamethasone significantly increases the expression of placental 11ß-HSD2 but not 11ß-HSD1, and decreases the weights of fetuses but not placentas. Antenatal exposure to betamethasone leads to either significant weight loss in the offspring younger than 10-week-old, or weight gain in those older than 14-week-old. Furthermore, antenatal exposure to betamethasone results in coexistence of various metabolic disorders in adult offspring, including hyperglycemia, glucose intolerance, low insulin secretory capacity and hyperlipidemia. The present study demonstrates that exposure of pregnant dams to betamethasone induces the expression of placental 11ß-HSD2 but not 11ß-HSD1, leads to fetal IUGR and causes adult metabolic disorders, providing evidence for fetal origins of adult diseases and the potential role of placental 11ß-HSD2 in them.

Up-regulation of 11ß-Hydroxysteroid Dehydrogenase Type 2 Expression by Hedgehog Ligand Contributes to the Conversion of Cortisol Into Cortisone.

The cortisol-inactivating enzyme 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2) that catalyzes the intracellular inactivation of glucocorticoids plays a pivotal role in human pregnant maintenance and normal fetal development. Given the fact that the main components of Hedgehog (HH) signaling pathway are predominantly expressed in syncytial layer of human placental villi where 11ß-HSD2 is robustly expressed, in the present study, we have investigated the potential roles and underlying mechanisms of HH signaling in 11ß-HSD2 expression. Activation of HH signaling by a variety of approaches robustly induced 11ß-HSD2 expression as well as the 11ß-HSD2 activity, whereas suppression of HH signaling significantly attenuated 11ß-HSD2 expression as well as the 11ß-HSD2 activity in both human primary cytotrophoblasts and trophoblast-like BeWo cells. Moreover, among glioma-associated oncogene (GLI) family transcriptional factors in HH signaling, knockdown of GLI2 but not GLI1 and GLI3 significantly attenuated HH-induced 11ß-HSD2 expression and activity, and overexpression of GLI2 activator alone was sufficient to induce 11ß-HSD2 expression and activity. Finally, GLI2 not only directly bound to the promoter region of gene hsd11b2 to transactivate hsd11b2 but also formed a heterodimer with RNA polymerase II, an enzyme that catalyzes the transcription of DNA to synthesize mRNAs, resulting in up-regulation of hsd11b2 gene transcription. Taken together, the present study has uncovered a hitherto uncharacterized role of HH/GLI2 signaling in 11ß-HSD2 regulation, implicating that HH signaling through GLI2 could be required for the human pregnant maintenance and fetal development.

Glioma-associated Oncogene 2 Is Essential for Trophoblastic Fusion by Forming a Transcriptional Complex with Glial Cell Missing-a.

Cell-cell fusion of human villous trophoblasts, referred to as a process of syncytialization, acts as a prerequisite for the proper development and functional maintenance of the human placenta. Given the fact that the main components of the Hedgehog signaling pathway are expressed predominantly in the syncytial layer of human placental villi, in this study, we investigated the potential roles and underlying mechanisms of Hedgehog signaling in trophoblastic fusion. Activation of Hedgehog signaling by a variety of approaches robustly induced cell fusion and the expression of syncytial markers, whereas suppression of Hedgehog signaling significantly attenuated cell fusion and the expression of syncytial markers in both human primary cytotrophoblasts and trophoblast-like BeWo cells. Moreover, among glioma-associated oncogene (GLI) family transcriptional factors in Hedgehog signaling, knockdown of GLI2 but not GLI1 and GLI3 significantly attenuated Hedgehog-induced cell fusion, whereas overexpression of the GLI2 activator alone was sufficient to induce cell fusion. Finally, GLI2 not only stabilized glial cell missing-a, a pivotal transcriptional factor for trophoblastic syncytialization, but also formed a transcriptional heterodimer with glial cell missing-a to transactivate syncytin-1, a trophoblastic fusogen, and promote trophoblastic syncytialization. Taken together, this study uncovered a so far uncharacterized role of Hedgehog/GLI2 signaling in trophoblastic fusion, implicating that Hedgehog signaling, through GLI2, could be required for human placental development and pregnancy maintenance.

Hedgehog signaling through GLI1 and GLI2 is required for epithelial-mesenchymal transition in human trophoblasts.

BACKGROUND: Epithelial to mesenchymal transition (EMT) is critical for human placental development, trophoblastic differentiation, and pregnancy-associated diseases. Here, we investigated the effects of hedgehog (HH) signaling on EMT in human trophoblasts, and further explored the underlying mechanism. METHODS: Human primary cytotrophoblasts and trophoblast-like JEG-3 cells were used as in vitro models. Quantitative real-time RT-PCR and Western blot analysis were performed to examine mRNA and protein levels, respectively. Lentiviruses expressing short hairpin RNA were used to knock down the target genes. Reporter assays and chromatin immunoprecipitation were performed to determine the transactivity. Cell migration, invasion and colony formation were accessed by wound healing, Matrigel-coated transwell, and colony formation assays, respectively. RESULTS: Activation of HH signaling induced the transdifferentiation of cytotrophoblasts and trophoblast-like JEG-3 cells from epithelial to mesenchymal phenotypes, exhibiting the decreases in E-Cadherin expression as well as the increases in vimentin expression, invasion, migration and colony formation. Knockdown of GLI1 and GLI2 but not GLI3 attenuated HH-induced transdifferentiation, whereas GLI1 was responsible for the expression of HH-induced key EMT regulators including Snail1, Slug, and Twist, and both GLI1 and GLI2 acted directly as transcriptional repressor of CDH1 gene encoding E-Cadherin. CONCLUSION: HH through GLI1 and GLI2 acts as critical signals in supporting the physiological function of mature placenta. GENERAL SIGNIFICANCE: HH signaling through GLI1 and GLI2 could be required for the maintenance of human pregnancy.

Hedgehog signaling stimulates the conversion of cholesterol to steroids.

Cholesterol modification of Hedgehog (Hh) ligands is fundamental for the activity of Hh signaling, and cholesterol biosynthesis is also required for intracellular Hh signaling transduction. Here, we investigated the roles and underlying mechanism of Hh signaling in metabolism of cholesterol. The main components of the Hh pathway are abundantly expressed in both human cytotrophoblasts and trophoblast-like cells. Activation of Hh signaling induces the conversion of cholesterol to progesterone (P4) and estradiol (E2) through up-regulating the expression of steroidogenic enzymes including P450 cholesterol side chain cleavage enzyme (P450scc), 3ß-hydroxysteroid dehydrogenase type 1 (3ß-HSD1), and aromatase. Moreover, inhibition of Hh signaling attenuates not only Hh-induced expression of steroidogenic enzymes but also the conversion of cholesterol to P4 and E2. Whereas Gli3 is required for Hh-induced P450scc expression, Gli2 mediates the induction of 3ß-HSD1 and aromatase. Finally, in ovariectomized nude mice, systemic inhibition of Hh signaling by cyclopamine suppresses circulating P4 and E2 levels derived from a trophoblast-like choricarcinoma xenograft, and attenuates uterine response to P4 and E2. Together these results uncover a hitherto uncharacterized role of Hh signaling in metabolism of cholesterol.