The Synergistic Effect of Valsartan and LAF237 [(S)-1-[(3-Hydroxy-1-Adamantyl)Ammo]acetyl-2-Cyanopyrrolidine] on Vascular Oxidative Stress and Inflammation in Type 2 Diabetic Mice

Aim. To investigate the combination effects and mechanisms of valsartan (angiotensin II type 1 receptor blocker) and LAF237 (DPP-IV inhibitor) on prevention against oxidative stress and inflammation injury in db/db mice aorta. Methods. Db/db mice (n = 40) were randomized to receive valsartan, LAF237, valsartan plus LAF237, or saline. Oxidative stress and inflammatory reaction in diabetic mice aorta were examined. Results. Valsartan or LAF237 pretreatment significantly increased plasma GLP-1 expression, reduced apoptosis of endothelial cells isolated from diabetic mice aorta. The expression of NAD(P)H oxidase subunits also significantly decreased resulting in decreased superoxide production and ICAM-1 (fold change: valsartan : 7.5 ± 0.7, P < 0.05; LAF237: 10.2 ± 1.7, P < 0.05), VCAM-1 (fold change: valsartan : 5.2 ± 1.2, P < 0.05; LAF237: 4.8 ± 0.6, P < 0.05), and MCP-1 (fold change: valsartan: 3.2 ± 0.6, LAF237: 4.7 ± 0.8; P < 0.05) expression. Moreover, the combination treatment with valsartan and LAF237 resulted in a more significant increase of GLP-1 expression. The decrease of the vascular oxidative stress and inflammation reaction was also higher than monotherapy with valsartan or LAF237. Conclusion. These data indicated that combination treatment with LAF237 and valsartan acts in a synergistic manner on vascular oxidative stress and inflammation in type 2 diabetic mice

Effect of the structure of alkyl salicylaldoxime on extraction of copper(II)

Four kinds of alkyl salicylaldoxime (AS) were investigated to probe the effect of molecular structure on the extraction of Cu(II). With the augment of R groups, tert-octylsalicylaldoxime and nonylsalicylaldoxime have much stronger extraction ability for Cu(II) than salicylaldoxime and tert-butylsalicylaldoxime, which is consistent with the rise of hydrophobicity (Log P) of the extractants. The umbrella structure of the R group can endow tert-octylsalicylaldoxime with stronger steric-hindrance effect than nonylsalicylaldoxime, which results in the better separation efficiency of Cu(II) from Fe(III) for tert-octylsalicylaldoxime. The extraction ability of the extractants for Cu(II) is related to the hydrophobicity and molecular size, as predicted from quantum chemistry calculation

Noninvasive visualization of microRNA-16 in the chemoresistance of gastric cancer using a dual reporter gene imaging system.

MicroRNAs (miRNAs) have been implicated to play a central role in the development of drug resistance in a variety of malignancies. However, many studies were conducted at the in vitro level and could not provide the in vivo information on the functions of miRNAs in the anticancer drug resistance. Here, we introduced a dual reporter gene imaging system for noninvasively monitoring the kinetic expression of miRNA-16 during chemoresistance in gastric cancer both in vitro and in vivo. Human sodium iodide symporter (hNIS) and firefly luciferase (Fluc) genes were linked to form hNIS/Fluc double fusion reporter gene and then generate human gastric cancer cell line NF-3xmir16 and its multidrug resistance cell line NF-3xmir16/VCR. Radioiodide uptake and Fluc luminescence signals in vitro correlated well with viable cell numbers. The luciferase activities and radioiodide uptake in NF-3xmir16 cells were remarkably repressed by exogenous or endogenous miRNA-16. The NF-3xmir16/VCR cells showed a significant increase of (131)I uptake and luminescence intensity compared to NF-3xmir16 cells. The radioactivity from in vivo (99m)Tc-pertechnetate imaging and the intensity from bioluminescence imaging were also increased in NF-3xmir16/VCR compared with that in NF-3xmir16 tumor xenografts. Furthermore, using this reporter gene system, we found that etoposide (VP-16) and 5-fluorouracil (5-FU) activated miRNA-16 expression in vitro and in vivo, and the upregulation of miRNA-16 is p38MAPK dependent but NF-κB independent. This dual imaging reporter gene may be served as a novel tool for in vivo imaging of microRNAs in the chemoresistance of cancers, as well as for early detection and diagnosis in clinic

Regulation of the NRG1/ErbB4 Pathway in the Intrinsic Cardiac Nervous System Is a Potential Treatment for Atrial Fibrillation

Background: The NRG1/ErbB4 signaling mechanism has been widely studied in the central nervous system for many years. However, the role of this pathway in modulating the intrinsic cardiac nervous system is largely unknown.Objective: The present study investigated whether the NRG1/ErbB4 signaling system affects the activity of major atrial ganglionated plexi (GP) in a paroxysmal atrial fibrillation (AF) model by 6-h rapid atrial pacing (RAP).Methods: Twenty-four dogs were randomly divided into (1) a control group (saline microinjections into GP), (2) RAP group (saline microinjections into GP plus 6 h-RAP), (3) NRG1 group (microinjections of neuregulin-1 into GP plus 6 h-RAP) and (4) NRG1 + ERA group (microinjections of neuregulin-1 and ErbB4 receptor antagonist-ERA into GP plus 6 h-RAP). The effective refractory period (ERP), window of vulnerability (WOV), anterior right GP (ARGP) function and neural activity were measured. ARGP tissues were excised for histological study and western blotting.Results: When compared to the control group, 6 h-RAP produced a significant (1) decrease in ERP, an increase in ΣWOV, (2) an increase in ARGP neural activity and neural function, and (3) an increase in c-fos and nerve growth factor protein expression in the ARGP. However, microinjection of NRG1 into the ARGP prior to RAP prevented ERP shortening and AGRP activity enhancement and inhibited the expression of c-Fos and NGF proteins. Furthermore, these changes were significantly attenuated by pretreatment with an ErbB4 receptor antagonist.Conclusion: The NRG1/ErbB4 signaling pathway may exist in the GP, and activation of this pathway suppressed RAP-induced GP activation, atrial electrical remodeling and AF

Visualization of differential expression of miRNA-16 in MDR gastric cancer cells.

<p>(A, B) <i>In vitro</i> bioluminescence imaging of NF-3xmir16 and NF-3xmir16/VCR cells with equal numbers (1×10⁶). (C) The relative of radioiodide uptake between NF-3xmir16 and NF-3xmir16/VCR cells. Data are shown as fold changes in NF-3xmir16/VCR relative to NF-3xmir16 cells, which are set as 1. (D) Quantitative RT-PCR detected miRNA-16 expression in NF-3xmir16 and NF-3xmir16/VCR cells. Triplicate assays were performed for each RNA sample and the relative expression of miRNA-16 was normalized to U6 snRNA. Data are shown as fold change of miRNA levels in NF-3xmir16/VCR relative to NF-3xmir16 cells, which are set as 1. (E) Equal numbers (1×10⁷) of NF-3xmir16 and NF-3xmir16/VCR cells were respectively xenografted into left and right hind limb of each mouse (n = 6). Injection of D-luciferin (150 mg/kg) and then the <i>in vivo</i> bioluminescence imaging was performed. (F) Injection of ^99mTc-pertechnetate (18.5 MBq) and acquisition of ^99mTc-pertechnetate gamma camera imaging. Data are shown as fold changes in NF-3xmir16/VCR xenografts relative to NF-3xmir16 xenografts, which are set as 1. ^*P<0.05, ^**P<0.005. T = thyroid; S = stomach; B = bladder.</p

MiRNA-16 was upregulated by VP-16 and 5-FU anticancer drugs.

<p>(A, B) NF-3xmir16/cells were treated with VP-16 (5 µg/ml), MMC (0.5 µg/ml), ADR (0.2 µg/ml), 5-FU (10 µmol/L) and CDDP (5 µmol/L), respectively for 48 h and <i>in vitro</i> bioluminescence imaging was performed. Results are expressed as mean ± SD of 3 independent experiments. (C, D) NF-empty cells were treated with the above drugs and <i>in vitro</i> bioluminescence imaging was performed as described in (A). Results are expressed as mean ± SD of 3 independent experiments. (E) NF-3xmir16 cells were treated with the above drugs for 48 h and radioiodide uptake assay were performed. (F) Quantitative RT-PCR detected miRNA-16 expression in drug treated and untreated NF-3xmir16 cells. Triplicate assays were performed for each RNA sample and the relative expression of miRNA-16 was normalized to U6 snRNA. Results are expressed as mean ± SD of 3 independent experiments. ^*P<0.05, ^**P<0.005, ^***P<0.001 compared with untreated cells.</p

Monitoring of exogenous and endogenous miRNA-16 expression <i>in vitro</i> and <i>in vivo</i>.

<p>(A, B) <i>In vitro</i> bioluminescence imaging and (C) radioiodide uptake assay after transfecting miRNA-16 or negative control (NC) RNA oligos (50 nM) into NF-3xmir16 cells. Imaging analysis program (Living Image software version 2.50) was used to quantify the bioluminescence intensity. Triplicate independent experiments were performed for each assay. Data are shown as fold changes in miRNA-16 transfected cells relative to NC transfected cells, which is set as 1. (D, E) <i>In vitro</i> bioluminescence imaging of NF-empty and NF-3xmir16 cells with equal numbers (1×10⁶). (F) The relative of radioiodide uptake between NF-empty and NF-3xmir16 cells. Data are shown as fold changes in NF-3xmir16 relative to NF-empty cells, which are set as 1. (G) Equal numbers (1×10⁷) of NF-empty and NF-3xmir16 cells were respectively xenografted into left and right hind limb of each mouse (n = 6). Injection of D-luciferin (150 mg/kg) and then <i>in vivo</i> bioluminescence imaging was performed. (H) Injection of ^99mTc-pertechnetate (18.5 MBq) and gamma camera imaging was performed. Data are shown as fold changes in NF-3xmir16 xenografts relative to NF-empty xenografts, which are set as 1. ^*P<0.05, ^**P<0.005. T = thyroid; S = stomach; B = bladder.</p

Bioluminescence imaging of enhanced miRNA-16 expression by VP-16 and 5-FU in nude mice.

<p>Different numbers of NF-empty (1×10⁵ cells) and NF-3xmir16 (1×10⁷ cells) were respectively xenografted onto the left and right hindlimb of each mouse (n = 6). Then VP-16 (A and B, 0.38 mg/kg) or 5-FU (C and D, 30 mg/kg) were intraperitoneally administrated into mice every 24 h. Before and after VP-16 or 5-FU treatment for 48 h, D-luciferin (150 mg/kg) was injected and bioluminescence imaging was acquired. Data are shown as fold changes in various groups relative to NF-empty untreated xenograft, which is set as 1. ^*P<0.05 compared with untreated xenografts.</p