Cluster of differentiation 44 (CD44), a cell surface receptor for hyaluronic acid (HA), is involved in aggressive cancer phenotypes. Herein, we investigated the role of the CD44 standard isoform (CD44s) in hypoxia-inducible factor-1α (HIF-1α) regulation using MCF7 overexpressing CD44s (pCD44s-MCF7). When pCD44s-MCF7 was incubated under hypoxia, levels of HIF-1α, vascular endothelial growth factor, and the HIF-1α response element-derived luciferase activity were significantly increased compared to those in the control MCF7. Incubation of pCD44s-MCF7 cells with HA further increased HIF-1α accumulation, and the silencing of CD44s attenuated HIF-1α elevation, which verifies the role of CD44s in HIF-1α regulation. In addition, the levels of phosphorylated extracellular signal-regulated kinase (ERK) was higher in hypoxic pCD44s-MCF7 cells, and HIF-1α accumulation was diminished by the pharmacological inhibitors of ERK. CD44s-mediated HIF-1α augmentation resulted in two functional outcomes. First, pCD44s-MCF7 cells showed facilitated cell motility under hypoxia via the upregulation of proteins associated with epithelial-mesenchymal transition, such as SNAIL1 and ZEB1. Second, pCD44s-MCF7 cells exhibited higher levels of glycolytic proteins, such as glucose transporter-1, and produced higher levels of lactate under hypoxa. As a consequence of the enhanced glycolytic adaptation to hypoxia, pCD44s-MCF7 cells exhibited a higher rate of cell survival under hypoxia than that of the control MCF7, and glucose deprivation abolished these differential responses of the two cell lines. Taken together, these results suggest that CD44s activates hypoxia-inducible HIF-1α signaling via ERK pathway, and the CD44s-ERK-HIF-1α pathway is involved in facilitated cancer cell viability and motility under hypoxic conditions.
Anoxia ; Breast Neoplasms* ; Breast* ; Cell Line ; Cell Movement ; Cell Survival ; Epithelial-Mesenchymal Transition ; Glucose ; Glycolysis ; Hyaluronic Acid ; Lactic Acid ; Luciferases ; MAP Kinase Signaling System ; Phenotype ; Phosphotransferases ; Up-Regulation ; Vascular Endothelial Growth Factor A

Exercise is one of the most common stressors in horses. Although various physiological parameters such as cortisol respond to exercise, there is no reliable parameter for the measurement of exercise-induced stress in sport horses. This study was performed to discover a new biomarker with high sensitivity for exercise-induced stress. The expression of fos mRNA was increased more than 10-fold in horse blood samples collected after an hour of exercise, as compared with before the exercise. The plasma cortisol levels were also increased after the exercise, but only by about two-fold. The fos mRNA levels were well-correlated with plasma cortisol concentrations. These findings suggest that fos mRNA expression in blood may be useful for the measurement of exercise-induced stress in horses.
Horses* ; Hydrocortisone ; Plasma ; RNA, Messenger ; Sports

Purpose: Appendectomy is one of the most common surgeries in children. Although various radiological examinations are performed, they do not always reveal a definitive diagnosis of appendicitis. This study aimed to investigate the clinical course of equivocal appendicitis, identify the factors associated with appendectomy, and suggest appropriate management for these patients. Methods: Patients younger than 19 years who visited Seoul National University Bundang Hospital with a differential diagnosis of appendicitis from January 2013 to December 2017 were included. All participants conducted ‘appendiceal CT’ with a scoring scale of 1–5. The higher the score, the higher the likelihood of a radiologic diagnosis of appendicitis. We defined the appendicitis CT score of 2–4 as equivocal appendicitis (n = 143). Medical records were reviewed retrospectively for demographics, further examination as abdominal ultrasonography, and appendectomy status (yes or no). The mean follow-up period was 15.6 ± 71 days. Results: Equivocal appendicitis accounted for 16.7%. Additional ultrasonography test was performed in 24.5% (35 of 143). In total, 34 patients (23.8%) underwent appendectomy. Among the patients with appendiceal CT scores 2, 3, and 4, 4.9%, 50.0%, and 87.5% underwent appendectomy, respectively. Higher WBC count, higher appendicitis CT score, and readmission were significantly associated with appendectomy in patients with equivocal appendicitis. Conclusion Higher appendicitis CT score and WBC level were positively associated with appendectomy. Careful observation can be a treatment option in appendicitis CT score 2 or 3 groups. Appendectomy is the first-line treatment for patients with appendicitis score 4. Additional ultrasonography test is advisable to determine treatment modality for equivocal appendicitis.

Hodgson's bats are critically endangered in South Korea. This study analyzed the concentrations of elements in liver, kidney, and intestine tissues from a Hodgson's bat found dead in the wild. The concentrations of essential elements followed the order Fe > Zn > Cu >Mn > Se in the three tissues. Hg was detected at the highest concentrations among the non-essential elements analyzed in the liver and kidney tissues, while As was the most highly concentrated non-essential element in the intestine. To the best of our knowledge, this is the first study of tissue element concentrations in Hodgson's bats.
Chiroptera ; Intestines* ; Kidney* ; Korea ; Liver*