E-cigarette exposure causes early pro-atherogenic changes in an inducible murine model of atherosclerosis

Introduction: Evidence suggests that e-cigarette use (vaping) increases cardiovascular disease risk, but decades are needed before people who vape would develop pathology. Thus, murine models of atherosclerosis can be utilized as tools to understand disease susceptibility, risk and pathogenesis. Moreover, there is a poor understanding of how risk factors for atherosclerosis (i.e., hyperlipidemia, high-fat diet) intersect with vaping to promote disease risk. Herein, we evaluated whether there was early evidence of atherosclerosis in an inducible hyperlipidemic mouse exposed to aerosol from commercial pod-style devices and e-liquid.Methods: Mice were injected with adeno-associated virus containing the human protein convertase subtilisin/kexin type 9 (PCSK9) variant to promote hyperlipidemia. These mice were fed a high-fat diet and exposed to room air or aerosol derived from JUUL pods containing polyethylene glycol/vegetable glycerin (PG/VG) or 5% nicotine with mango flavoring for 4 weeks; this timepoint was utilized to assess markers of atherosclerosis that may occur prior to the development of atherosclerotic plaques.Results: These data show that various parameters including weight, circulating lipoprotein/glucose levels, and splenic immune cells were significantly affected by exposure to PG/VG and/or nicotine-containing aerosols.Discussion: Not only can this mouse model be utilized for chronic vaping studies to assess the vascular pathology but these data support that vaping is not risk-free and may increase CVD outcomes later in life

C (Control) raw RNA-Seq BAM file

C/C’ pre-B cells sorted from control mice. This is the BAM file containing the unprocessed, raw reads for the control sample. The data is provided in BAM format for convenience. MD5: 1db0c4591f24b1e9d4b21b75d33df61

Data from: Tungsten blocks murine B lymphocyte differentiation and proliferation through downregulation of IL-7 receptor/Pax5 signaling

Tungsten is an emerging environmental toxicant associated with several pediatric leukemia clusters, although a causal association has not been established. Our previous work demonstrated that tungsten exposure resulted in an accumulation of pre-B cells in the bone marrow, the same cell type that accumulates in pediatric acute lymphoblastic leukemia (ALL). To better understand the relevant molecular mechanisms, we performed RNA sequencing on flow sorted pre-B cells from control and tungsten-exposed mice. Tungsten decreased the expression of multiple genes critical for B cell development, including members of the IL-7R and pre-BCR signaling pathways, such as Jak1, Stat5a, Erb1, Pax5, Syk, and Ikzf3. These results were confirmed in an in vitro model of B cell differentiation, where tungsten arrested differentiation at the pro-B cell stage and inhibited proliferation. These changes were associated with decreased expression of multiple genes in the IL-7R signaling pathway and decreased percentage of IL-7R, phosphorylated STAT5 (pSTAT5) double-positive cells. Supplementation with IL-7 or overexpression of Pax5, the transcription factor downstream of IL-7R, rescued the tungsten-induced differentiation block. Together, these data support the hypothesis that IL-7R/Pax5 signaling axis is critical to tungsten-mediated effects on pre-B cell development. Importantly, many of these molecules are modulated in ALL

Arsenic Trioxide Overcomes Rapamycin-Induced Feedback Activation of AKT and ERK Signaling to Enhance the Anti-Tumor Effects in Breast Cancer

<div><p>Inhibitors of the mammalian target of rapamycin (mTORi) have clinical activity; however, the benefits of mTOR inhibition by rapamycin and rapamycin-derivatives (rapalogs) may be limited by a feedback mechanism that results in AKT activation. Increased AKT activity resulting from mTOR inhibition can be a result of increased signaling via the mTOR complex, TORC2. Previously, we published that arsenic trioxide (ATO) inhibits AKT activity and in some cases, decreases AKT protein expression. Therefore, we propose that combining ATO and rapamycin may circumvent the AKT feedback loop and increase the anti-tumor effects. Using a panel of breast cancer cell lines, we find that ATO, at clinically-achievable doses, can enhance the inhibitory activity of the mTORi temsirolimus. In all cell lines, temsirolimus treatment resulted in AKT activation, which was decreased by concomitant ATO treatment only in those cell lines where ATO enhanced growth inhibition. Treatment with rapalog also results in activated ERK signaling, which is decreased with ATO co-treatment in all cell lines tested. We next tested the toxicity and efficacy of rapamycin plus ATO combination therapy in a MDA-MB-468 breast cancer xenograft model. The drug combination was well-tolerated, and rapamycin did not increase ATO-induced liver enzyme levels. In addition, combination of these drugs was significantly more effective at inhibiting tumor growth compared to individual drug treatments, which corresponded with diminished phospho-Akt and phospho-ERK levels when compared with rapamycin-treated tumors. Therefore, we propose that combining ATO and mTORi may overcome the feedback loop by decreasing activation of the MAPK and AKT signaling pathways. </p> </div

Arsenic and temsirolimus combination treatment results in decreased phospho-S6 and ERK activation.

<p>MDA-MB-468, MCF-7, SkBr3, and T47D cell lines were exposed to vehicle control (Vh; 5.3 x 10^-6 N NaOH and 2.5 x 10^-5 % EtOH in PBS), 1-2 µM ATO, 0.5-5 ng/ml temsirolimus and the combinations for 24 hours. Whole cell extracts were used in immunoblotting experiments for phospho-S6, S6, phospho-ERK, ERK, and β-actin. Immunoblots shown are representative of experiments performed at least 3 times.</p

Addition of ATO decreases rapamycin-induced AKT activation <i>in</i><i>vivo</i>.

<p>Tumor samples were stained with antibody against phospho-S473-AKT. Representative pictures of each treatment are shown (A). Quantification of staining intensity was performed using algorithms provided with the ImageScope software (B). Individual animals are represented with mean and standard error bars (n=4-5 mice). (C-D) Tumors at the end of the experiment were analyzed in immunoblotting experiments with antibodies against phospho-S473-AKT (C), phospho-T308-AKT (D), AKT, and β-actin. Band densitometry was performed and the relative intensity of phospho-AKT/AKT/β-actin was calculated. Individual animals are represented with mean and standard error bars (n= 8-9 mice).</p

Arsenic growth inhibition correlates with decreased temsirolimus-induced phospho-AKT.

<p>MDA-MB-468, MCF-7, SkBr3, and T47D cell lines were exposed to vehicle control (Vh; 5.3 x 10^-6 N NaOH and 2.5 x 10^-5 % EtOH in PBS), 1-2 µM ATO, 0.5-5 ng/ml temsirolimus and the combinations for 24 hours. Whole cell extracts were used in immunoblotting experiments for phospho-S473-AKT, phospho-T308-AKT, AKT, and β-actin. Immunoblots shown are representative of experiments performed at least 3 times.</p

Arsenic enhances temsirolimus-induced growth inhibition of selective breast cancer cell lines.

<p>(A) MDA-MB-468, MCF-7, SkBr3, and T47D cell lines were exposed to vehicle control (Vh; 5.3 x 10^-6 N NaOH and 2.5 x 10^-5 % EtOH in PBS), 2 µM arsenic trioxide (ATO), 5 ng/ml temsirolimus, or the combination for 48 hours and relative cell number assessed by SRB assay. (B&C) Cell lines were exposed to vehicle control (Vh), 1 µM ATO, 5 ng/ml temsirolimus, or the combination for 48 hours and stained with propidium iodide and assessed by flow cytometry for cell cycle analyses (B) or percentage of cells with fragmented DNA (C). Annexin V staining was performed in SkBr3 cells and the apoptotic cells were determined as those staining positive for annexin V, but negative fot 7AAD. Statistical significance is denoted as follows: * = p<0.05, ** = p<0.01, and *** = p<0.001. Experiments were performed at least three times with technical triplicates.</p