NDRG2 regulates the formation of reactive astrocyte-derived progenitor cells via Notch signaling pathway after brain traumatic injury in rats.

In response to traumatic brain injury, a subpopulation of cortical astrocytes is activated, resulting in acquisition of stem cell properties, known as reactive astrocytes-derived progenitor cells (Rad-PCs). However, the underlying mechanisms remain largely unknown during this process. In this study, we examined the role of N-myc downstream-regulated gene 2 (NDRG2), a differentiation- and stress-associated molecule, in Rad-PCs after cortical stab injury in adult rats. Immunohistochemical analysis showed that in the cerebral cortex of normal adult rats, NDRG2 was exclusively expressed in astrocytes. After liu cortical injury, the expression of NDRG2 was significantly elevated around the wound and most cells expressing NDRG2 also expressed GFAP, a reactive astrocyte marker. Importantly, NDRG2-expressing cells were co-labeled with Nestin, a marker for neural stem cells, some of which also expressed cell proliferation marker Ki67. Overexpression of NDRG2 further increased the number of NDRG2/Nestin double-labeling cells around the lesion. In contrast, shRNA knockdown of NDRG2 decreased the number of NDRG2+/Nestin+ cells. Intracerebroventricular administration of stab-injured rats with a Notch antagonist, DAPT, led to a significant decrease in Nestin+/NDRG2+ cells around the injured boundary, but did not affect NDRG2+ cells. Moreover, overexpression or knockdown of NDRG2 led to up- and down-regulation of the expression of Notch intracellular domain NICD and Notch target gene Hes1, respectively. Taken together, these results suggest that NDRG2 may play a role in controlling the formation of Rad-PCs in the cerebral cortex of adult rats following traumatic injury, and that Notch signaling pathway plays a key role in this process.

Flavonoids of Rosa roxburghii Tratt offers protection against radiation induced apoptosis and inflammation in mouse thymus.

The present study evaluated the protective effect of the natural compound flavonoids of Rosa roxburghii Tratt (FRT) against γ-radiation-induced apoptosis and inflammation in mouse thymus cells in vivo and in vitro. Thymus cells and mice were exposed to 60Co γ-ray at a dose of 6 Gy. The radiation treatment induced significant cell apoptosis and inflammation. Radiation increased the expressions of cleaved caspase 3/8-10, AIF, and PARP-1, and FRT could mitigate their activation and inhibit subsequent apoptosis in the thymus both in vitro or in vivo. Irradiation increased the mRNA expression of ICAM-1/VCAM-1, IL-1α/IL-6 and TNF-α/NF-κB. Our results also indicated that FRT alleviated gene expression of some inflammatory factors such as ICAM-1/VCAM-1, TNF-α/NF-κB, but not IL-1α/IL-6. Irradiation increased the protein expression levels of ICAM-1/VCAM-1, IL-1α/IL-6 and TNF-α/NF-Κb, and our results also indicated that FRT alleviated protein level expression of certain inflammatory factors such as ICAM-1, IL-1α/IL-6, TNF-α/NF-κB, but not VCAM-1. Our results suggested that FRT enhanced radioprotection at least partially by regulating caspase 3/8-10, AIF, and PARP-1 to reduce apoptosis and by regulating ICAM-1, IL-1α/IL-6, TNF-α/NF-κB to reduce inflammation.

Annexin V conjugated nanobubbles: A novel ultrasound contrast agent for in vivo assessment of the apoptotic response in cancer therapy.

In vivo assessment of apoptotic response to cancer therapy is believed to be very important for optimizing management of treatment. However, few noninvasive strategies are currently available to monitor the therapeutic response in vivo. Ultrasonography has been used to detect apoptotic cell death in vivo, but a high-frequency transducer is needed. Fortunately, the capability of ultrasound contrast agents (UCAs) to exit the leaky vasculature of tumors enables ultrasound-targeted imaging of molecular events in response to cancer therapy. In this study, we prepared a novel nano-sized UCA, namely, Annexin V-conjugated nanobubbles (AV-NBs, 635.5 ±â€¯25.4 nm). In vitro studies revealed that AV-NBs were relatively stable and highly echogenic. Moreover, these AV-NBs could easily extravasate into the tumor vasculature and recognize the apoptotic cells with high specificity and affinity in tumors sensitive to chemotherapy. Ultrasound imaging results demonstrated that AV-NBs had higher echogenicity and significantly greater enhancement compared with the untargeted control NBs (P < 0.01) inside the tumors after chemotherapy. Taken together, this study provides a promising method to accurately evaluate therapeutic effects at the molecular level to support cancer management.

A new and important relationship between miRNA-147a and PDPK1 in radiotherapy.

It was found that the expression level of miR-147a was significantly increased and the pathway of PI3K/AKT was dramatically inhibited after radiation. In view of the relationship between miRNA and target genes, we put forward the question, what is the relationship between PI3K/AKT and miR-147a? In order to find the answer to the question, we used bioinformatics techniques to analyze the relationship between miR-147 (a or b) and PI3K/AKT signaling pathway. miR-147a overexpression plasmid and PDPK1 3'UTR luciferase reporter gene plasmid were constructed. Dual luciferase reporter gene system validation experiments were carried out on miR-147a and PDPK1 relationship. The verification experiments were also carried out. Bioinformatics analysis showed that there is a miR-147a binding site in the non-coding region (3'UTR) of PDPK1. In the experimental groups transfected with wild type PDPK1 gene of 3'UTR plasmid, the luciferase activity decreased (or increased) significantly in miR-147a (or inhibitor) group compared with miR-NC (or anti-miR-NC); There was no significant difference between the miR-147a group (or inhibitor) and the miR-NC group (or anti-miR-NC) in the transfection of PDPK1-3'UTR-Mut gene vector. PDPK1 was a target gene for direct regulation of miR-147a downstream. Verifying test results showed that the expression of PDPK1 mRNA and protein was reduced after overexpression of miR-147a, which was up-regulated after silencing miR-147a in TC, and V79 cells. These results suggest that miR-147a could be involved in the regulation of PDPK1 transcription by binding to the target site in PDPK1 mRNA 3'UTR, and then regulated AKT.

Qualitative and quantitative analysis of catechin and quercetin in flavonoids extracted from Rosa roxburghii Tratt.

PURPOSE: To perform a qualitative and quantitative analysis of catechin and quercetin in flavonoids extracted from Rosa roxburghii Tratt. METHODS: Total flavonoids were determined using ultraviolet spectrophotometry (UV) at 500 nm. The optimal gradient program started with 15 % methanol and was kept within a period of 0 - 20 min, while 25 % methanol was kept within 20 - 33 min. Subsequently, the concentration of methanol was reduced to 15 % and was held for 10 min until the next injection. Mass spectrometry spray voltage was 4,000 V, ionization temperature 350 °C, atomizer pressure 35 psi, nitrogen flow rate 8 L/min, and mass scan range 200 - 800 m/z. The detection wavelength used for catechin and quercetin was 270 and 368 nm, respectively. RESULTS: Based on the UV results, Rosa roxburghii Tratt content was 73.85 %, which is in agreement with the national standard. Liquid chromatography-mass spectrometry (LC-MS) results indicate that Rosa roxburghii Tratt flavonoids contained quercetin, 34.26 %, with relative standard deviation (RSD) of 2.88 % and catechin content of 2.97 % with RSD of 1.49 %. CONCLUSION: The proposed measurement method for determining the content of flavonoids in Rosa roxburghii Tratt has the advantage of simplicity, feasibility, good repeatability, and rapid and accurate analysis.

Flavonoids of Rosa roxburghii Tratt Exhibit Anti-Apoptosis Properties by Regulating PARP-1/AIF.

Radioprotection is an important approach to reduce the side-effects of radiotherapy. The radioprotective effect of the flavonoids of Rosa roxburghii Tratt (FRT) has been confirmed, and the mechanism has been identified as theBcl-2/caspase-3/PARP-1 signaling pathway. In this study, we investigated the effects of FRT on the intercellular adhesion molecule (ICAM), and vascular cell adhesion protein (VCAM) in addition to apoptosis-related proteins such as Bax/Bcl-2, p-ERK/ERK, p-p53/p53, and p-p38/p38. In the present study, we focused on the effect of FRT on PARP-1/AIF. Ionizing radiation triggered the activation of PARP-1 and AIF translocation from the mitochondrion to the nucleus. The inhibition of PARP-1/AIF signaling pathway by FRT was investigated. Our results showed that the expressions of Bax/Bcl-2, p-ERK/ ERK, p-p53/p53, and p-p38/p38 were decreased after FRT treatment compared with the radiation-treated group. FRT inhibited PARP-1 activation to inhibit AIF translocation from mitochondrion to nucleus. Pretreatment with FRT diminished the comet's tail and reduced fragments in six Gy-irradiated thymocytes compared with the irradiated cells without FRT treatment. We conclude that FRT enhanced radioprotection at least partially by regulating PARP-1/AIF to reduce apoptosis. J. Cell. Biochem. 118: 3943-3952, 2017. © 2017 Wiley Periodicals, Inc.

Activating AKT to inhibit JNK by troxerutin antagonizes radiation-induced PTEN activation.

Radiotherapy is one of the most effective non-surgical treatments for many tumors. However, radiation damage remains a major negative consequence of radiotherapy. At present, radio-protective effect of troxerutin has been confirmed, but the mechanism of this radioprotection has not been elucidated. Here, this study showed that troxerutin protected thymus tissue of irradiated mice, and its radio-protective effect on thymocytes was significant in the range of 0.625-10µg/ml. Troxerutin significantly inhibited apoptosis of irradiated thymocytes at the concentration of 10µg/ml. Computer-aided drug design was used to investigate potential candidate targets for troxerutin, and an excellent correlation was identified between troxerutin and AKT (Pharm mapper and KEGG signal pathway). Troxerutin inhibited the activation of PTEN to stimulate AKT, which in turn prevented the activation of JNK to protect cells. Our results showed that troxerutin enhanced radioprotection at least partially by activating AKT to inhibit the activation of JNK.

Implementation of an objective testing system in noninvasive cardiac imaging for evaluation of pediatric cardiology fellows.

INTRODUCTION: Current evaluation of pediatric cardiology fellow performance is subjective and qualitative. More objective tools are recommended by credentialing boards and may provide more effective evaluation and education. OBJECTIVE: A series of training level-specific multiple-choice tests were developed and evaluated for their effectiveness as evaluation and educational tools for pediatric cardiology fellows. METHODS: Imaging tests were created by 3 attending physicians and one sonographer with combined expertise in echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography. Test content was derived from educational materials, textbooks, journal articles, and lectures previously given to the fellows. The tests were computerized and installed on the hospital intranet. After completion of each test, a posttest session was conducted between the fellow and the director of echocardiography to review concepts surrounding incorrect answers. A survey of the test use was then completed by each fellow. RESULTS: Four progressively more difficult tests corresponding to each 1-month image rotation and an advanced fifth test for fellows intending to subspecialize in noninvasive cardiac imaging were created. Fifteen fellows took 39 tests (test 1, 15 fellows; test 2, 9 fellows; test 3, 9 fellows; test 4, 4 fellows; and test 5, 2 fellows). The difficulty level of the tests was similar relative to fellow academic level. The majority of fellows welcomed more objective data provided by the tests and 93% of the fellows stated the posttest session was educational. CONCLUSION: Implementation of a fellow testing system using training level-specific computerized questions and images provides objective data for fellow performance evaluations and is a unique and beneficial educational tool.