Estrogen directly and specifically downregulates NaPi-IIa through the activation of both estrogen receptor isoforms (ERα and ERß) in rat kidney proximal tubule.

We have previously demonstrated that estrogen (E2) downregulates phosphate transporter NaPi-IIa and causes phosphaturia and hypophosphatemia in ovariectomized rats. In the present study, we examined whether E2 directly targets NaPi-IIa in the proximal tubule (PT) and studied the respective roles of estrogen receptor isoforms (ERα and ERß) in the downregulation of NaPi-IIa using both in vivo and an in vitro expression systems. We found that estrogen specifically downregulates NaPi-IIa but not NaPi-IIc or Pit2 in the kidney cortex. Proximal tubules incubated in a "shake" suspension with E2 for 24 h exhibited a dose-dependent decrease in NaPi-IIa protein abundance. Results from OVX rats treated with specific agonists for either ERα [4,4',4″;-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol, PPT] or ERß [4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol, DPN] or both (PPT + DPN), indicated that only the latter caused a sharp downregulation of NaPi-IIa, along with significant phosphaturia and hypophosphatemia. Lastly, heterologous expression studies demonstrated that estrogen downregulated NaPi-IIa only in U20S cells expressing both ERα and ERß, but not in cells expressing either receptor alone. In conclusion, these studies demonstrate that rat PT cells express both ERα and ERß and that E2 induces phosphaturia by directly and specifically targeting NaPi-IIa in the PT cells. This effect is mediated via a mechanism involving coactivation of both ERα and ERß, which likely form a functional heterodimer complex in the rat kidney proximal tubule.

Zinc deficiency augments leptin production and exacerbates macrophage infiltration into adipose tissue in mice fed a high-fat diet.

Zinc (Zn) deficiency and obesity are global public health problems. Zn deficiency is associated with obesity and comorbid conditions that include insulin resistance and type 2 diabetes. However, the function of Zn in obesity remains unclear. Using a mouse model of combined high-fat and low-Zn intake (0.5-1.5 mg/kg), we investigated whether Zn deficiency exacerbates the extent of adiposity as well as perturbations in metabolic and immune function. C57BL/6 mice were randomly assigned to receive either a high-fat diet (HFD) or a control (C) diet for 6 wk, followed by further subdivision into 2 additional groups fed Zn-deficient diets (C-Zn, HFD-Zn), along with a C diet and an HFD, for 3 wk (n = 8-9 mice/group). The extent of visceral fat, insulin resistance, or systemic inflammation was unaffected by Zn deficiency. Strikingly, Zn deficiency significantly augmented circulating leptin concentrations (HFD-Zn vs. HFD: 3.15 ± 0.16 vs. 2.59 ± 0.12 µg/L, respectively) and leptin signaling in the liver of obese mice. Furthermore, gene expression of macrophage-specific markers ADAM8 (A disintegrin and metalloproteinase domain-containing protein 8) and CD68 (cluster of differentiation 68) was significantly greater in adipose tissue in the HFD-Zn group than in the HFD group, as confirmed by CD68 protein analysis, indicative of increased macrophage infiltration. Inspection of Zn content and mRNA profiles of all Zn transporters in the adipose tissue revealed alterations of Zn metabolism to obesity and Zn deficiency. Our results demonstrate that Zn deficiency increases leptin production and exacerbates macrophage infiltration into adipose tissue in obese mice, indicating the importance of Zn in metabolic and immune dysregulation in obesity.

Pediatric Hypereosinophilia: Characteristics, Clinical Manifestations, and Diagnoses.

BACKGROUND: Eosinophilia is associated with various conditions, including allergic, infectious, and neoplastic disorders. The diagnostic differential is broad, and data on hypereosinophilia in pediatric patients are limited. OBJECTIVE: The objectives of this study were to identify cases of hypereosinophilia in a tertiary pediatric medical center, determine clinical characteristics and disease associations, and estimate the incidence of hypereosinophilia in the hospital and geographic populations. METHODS: A retrospective chart review included patients younger than 18 years presenting to a tertiary pediatric medical center (January 1, 2008, to May 31, 2017) with absolute eosinophil counts (AECs) greater than or equal to 1.50 thousand eosinophils/microliter (K/µL) recorded on at least 2 occasions at least 4 weeks apart (N = 176). Clinical characteristics, laboratory values, treatment course, and associated diagnoses were evaluated. RESULTS: The most common cause of hypereosinophilia in this cohort was secondary hypereosinophilia. Atopic dermatitis, graft-versus-host disease, sickle cell disease, and parasitic infections were the most common conditions associated with hypereosinophilia. Median age at diagnosis was 4.6 (interquartile range, 1.5-10.5) years. Median peak AEC was 3.16 (2.46-4.78) K/µL. Hypereosinophilia occurred most frequently in patients aged between 6 and 11 years (24.4%) and younger than 1 year (18.2%). Patients with neoplasms and immune deficiencies had significantly higher peak AECs than did patients with overlap hypereosinophilic syndrome and atopic diseases (P < .0001). CONCLUSIONS: Pediatric hypereosinophilia has an incidence of 54.4 per 100,000 persons per year, with children younger than 1 year and aged 6 to 11 years accounting for most affected patients. Pediatric hypereosinophilia is not uncommon and remains underrecognized, highlighting a need for clinicians to identify patients who meet criteria for hypereosinophilia and to pursue a thorough evaluation.

Demographic trends of sick leave absenteeism among civil service employees at a federal agency from 2004 to 2012.

OBJECTIVE: To investigate the associations between demographic variables and sick leave use. METHODS: We analyzed sick leave use among civil servants at a federal agency (FA) from 2004 to 2012 by demographic and FA-specific variables. We used a mixed methods approach and type III analysis to build a descriptive model of sick leave proportions and demographic variables. RESULTS: Sick absenteeism usage varied significantly (variation of greater than one sick day per year) by sex, Emergency Operations Center response tier, length of service at the FA, age, and general schedule pay grade level. Our final descriptive model contained age, sex, response tier and an interaction term between age and sex. CONCLUSIONS: Future studies should examine these associations on smaller time scales, perhaps breaking the data down by month or day of the week.

Zinc regulates the acute phase response and serum amyloid A production in response to sepsis through JAK-STAT3 signaling.

Sepsis rapidly activates the host inflammatory response and acute phase response. Severe sepsis, complicated by multiple organ failure, is associated with overwhelming inflammation and high mortality. We previously observed that zinc (Zn) deficiency significantly increases mortality in a mouse model of polymicrobial sepsis due to over-activation of the inflammatory response. In order to identify potential mechanisms that account for Zn-responsive effects, we generated whole exome expression profiles from the lung tissue of septic mice that were maintained on Zn modified diets. Based on systems analysis, we observed that Zn deficiency enhances the acute phase response and particularly the JAK-STAT3 pathway, resulting in increased serum amyloid A production. In vitro studies of primary hepatocytes and HepG2 cells substantiated that Zn-deficiency augments serum amyloid A production through up-regulation of the JAK-STAT3 and NF-κB pathways. In contrast, Zn inhibited STAT3 activation through the up-regulation of SHP1 activity. Collectively, these findings demonstrate that Zn deficiency enhances the acute phase response through up-regulation of the JAK-STAT3 pathway, thereby perpetuating increased inflammation that may lead to increased morbidity and mortality in response to sepsis.