MiR-133a inhibits fracture healing via targeting RUNX2/BMP2.

OBJECTIVE: To analyze the mechanism of miR-133a in inhibiting fracture healing through regulating runt-related transcription factor 2 (RUNX2) signaling pathway. PATIENTS AND METHODS: A total of 80 patients with fracture admitted to our hospital from January 2016 to January 2017 were divided into 2 groups according to nonunion fracture or healing fracture: nonunion fracture group (n = 40) and control group (n= 40). After admission, patients underwent the surgery, respectively, and the bone tissues were taken for stand-by application. The expression level of bone morphogenetic protein 2 (BMP2) was detected using the immunohistochemical method, the expression level of RUNX2 protein was detected by Western blotting, and the expression level of micro ribonucleic acid (miR)-133a was detected by quantitative polymerase chain reaction (qPCR). Moreover, the bioinformatics method was used to predict the target gene of miR-133a, and the luciferase reporter gene was used to detect the binding of miR-133a to RUNX2. RESULTS: Compared with those in control group, the expression of BMP2 and the relative expressions of RUNX2 protein and miR-133a were significantly decreased; the differences were statistically significant (p < 0.05). Pearson correlation analysis showed that miR-133a was negatively correlated with RUNX2. After overexpression of miR-133a, the expression level of RUNX2 was decreased, but it was increased significantly after interference in miR-133a. Besides, it was found in dual-luciferase reporter assay that miR-133a bound to RUNX2. CONCLUSIONS: MiR-133a inhibits the bone formation through inhibiting the RUNX2/BMP2 signaling pathway, thereby negatively regulating the fracture healing.

Overexpression of PIK3CA in murine head and neck epithelium drives tumor invasion and metastasis through PDK1 and enhanced TGFß signaling.

Head and neck squamous cell carcinoma (HNSCC) patients have a poor prognosis, with invasion and metastasis as major causes of mortality. The phosphatidylinositol 3-kinase (PI3K) pathway regulates a wide range of cellular processes crucial for tumorigenesis, and PIK3CA amplification and mutation are among the most common genetic alterations in human HNSCC. Compared with the well-documented roles of the PI3K pathway in cell growth and survival, the roles of the PI3K pathway in tumor invasion and metastasis have not been well delineated. We generated a PIK3CA genetically engineered mouse model (PIK3CA-GEMM) in which wild-type PIK3CA is overexpressed in head and neck epithelium. Although PIK3CA overexpression alone was not sufficient to initiate HNSCC formation, it significantly increased tumor susceptibility in an oral carcinogenesis mouse model. PIK3CA overexpression in mouse oral epithelium increased tumor invasiveness and metastasis by increasing epithelial-mesenchymal transition and by enriching a cancer stem cell phenotype in tumor epithelial cells. In addition to these epithelial alterations, we also observed marked inflammation in tumor stroma. AKT is a central signaling mediator of the PI3K pathway. However, molecular analysis suggested that progression of PIK3CA-driven HNSCC is facilitated by 3-phosphoinositide-dependent protein kinase (PDK1) and enhanced transforming growth factor ß (TGFß) signaling rather than by AKT. Examination of human HNSCC clinical samples revealed that both PIK3CA and PDK1 protein levels correlated with tumor progression, highlighting the significance of this pathway. In summary, our results offer significant insight into how PIK3CA overexpression drives HNSCC invasion and metastasis, providing a rationale for targeting PI3K/PDK1 and TGFß signaling in advanced HNSCC patients with PIK3CA amplification.

Effects of Five Naturally Occurring Sugars on the Longevity, Oogenesis, and Nutrient Accumulation Pattern in Adult Females of the Synovigenic Parasitoid Neochrysocharis formosa (Hymenoptera: Eulophidae).

Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae), one of the dominant natural enemies of agromyzid leafminers, is a synovigenic parasitoid. We compared the longevity, oogenesis, and nutrient levels of female wasps provided with 10% solutions of five naturally occurring sugars. All five sugars significantly increased the longevity of female wasps, which was 6.5-9.3-fold higher than that of parasitoids provided with water only. We found no significant difference in longevity of female wasps fed on glucose versus fructose or trehalose versus melezitose, but longevity of wasps fed on glucose or fructose was significantly longer than those fed on trehalose or melezitose. Also, we examined the oosorption capability of wasps fed on the five sugars. Some mature eggs were present in the ovaries of newly emerged females, but these were fully reabsorbed within 72 h when wasps were starved. Once wasps were fed with any of the sugars, the number of mature eggs increased at first and then decreased due to oosorption. The longevity and oogenesis dynamics of female wasps fed on five sugars were related with their function of hydrolysis and digestion. As female wasps have no lipogenesis capability, by acquiring exogenous sugars for oogenesis, they can either maintain or exceed the original level of capital nutrients held on adult emergence because none of the wasps' glycogen need be metabolized to burn as sugar.

Redox-dependent Brca1 transcriptional regulation by an NADH-sensor CtBP1.

C-terminal binding protein 1 (CtBP1) is a transcriptional co-repressor and metabolic sensory protein, which often represses tumor suppressor genes. Hence, we sought to determine if CtBP1 affects expression of the tumor suppressor Brca1 in head and neck tissue, as downregulation of Brca1 begins at the early stages of head and neck squamous cell carcinomas (HNSCCs). We found that CtBP1 represses Brca1 transcription by binding to the E2F4 site of the Brca1 promoter. Additionally, the recruitment of CtBP1 to the Brca1 promoter is redox-dependent, that is, increased at high NADH levels in hypoxic conditions. Further, immunostaining using a human HNSCC tissue array revealed that nuclear CtBP1 staining began to accumulate in hyperplasic lesions and HNSCCs, this staining correlated with Brca1 downregulation in these lesions. Pharmacological disruption of CtBP1 binding to Brca1 promoter by the antioxidant Tempol, which reduces NADH levels, relieved CtBP1-mediated repression of Brca1, leading to increased DNA repair in HNSCC cells. As tumor cells are generally hypoxic with increased NADH levels, the dynamic control of Brca1 by a 'metabolic switch' found in this study not only provides an important link between tumor metabolism and tumor suppressor expression but also suggests a potential chemo preventative or therapeutic strategy for HNSCC by blocking NADH-dependent CtBP1 activity at early stages of HNSCC carcinogenesis.

Inhibition of group A streptococcal infection by Melaleuca alternifolia (tea tree) oil concentrate in the murine model.

AIMS: To investigate the effect of a water-soluble Melaleuca alternifolia concentrate (MAC) on group A streptococcus (GAS; Streptococcus pyogenes)-induced necrotizing fasciitis. METHODS AND RESULTS: MAC pretreatment (1% and 2% v/v) was able to protect mice from GAS infection in an air pouch model. GAS-induced mouse death and skin injury were inhibited dose dependently by MAC. Administration of MAC at 6 h post-GAS infection partially delayed mouse death. Surveys of the exudates of the air pouch of MAC-treated mice revealed that the survival of infiltrating cells was prolonged, the bacteria were eliminated, and the production of inflammatory cytokines was inhibited. MAC could directly inhibit the growth of GAS in vitro, and the minimal inhibitory concentration (MIC) of MAC for GAS was determined as 0.05% v/v using the time-kill assay. Furthermore, a sub-MIC dose of MAC not only enhanced the bactericidal activity of RAW264.7 macrophage cells against GAS but also increased susceptibility of GAS for blood clearance. CONCLUSIONS: These results suggest that MAC may inhibit GAS-induced skin damage and mouse death by directly inhibiting GAS growth and enhancing the bactericidal activity of macrophages. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results provide scientific data on the use of MAC for the treatment of GAS-induced necrotizing fasciitis in the murine model.

Observation of Multi-TeV Gamma Rays from the Crab Nebula using the Tibet Air Shower Array.

The Tibet experiment, operating at Yangbajing (4300 m above sea level), is the lowest energy air shower array, and the new high-density array constructed in 1996 is sensitive to gamma-ray air showers at energies as low as 3 TeV. With this new array, the Crab Nebula was observed in multi-TeV gamma-rays and a signal was detected at the 5.5 sigma level. We also obtained the energy spectrum of gamma-rays in the energy region above 3 TeV which partially overlaps those observed with imaging atmospheric Cerenkov telescopes. The Crab spectrum observed in this energy region can be represented by the power-law fit dJ&parl0;E&parr0;&solm0;dE=&parl0;4.61+/-0.90&parr0;x10-12&parl0;E&solm0;3 TeV&parr0;-2.62+/-0.17 cm-2 s-1 TeV-1. This is the first observation of gamma-ray signals from point sources with a conventional air shower array using scintillation detectors.