Ablation of Doublecortin-Like Kinase 1 in the Colonic Epithelium Exacerbates Dextran Sulfate Sodium-Induced Colitis

We would like to acknowledge Jim Henthorn of the University of Oklahoma Health Sciences Center Flow Cytometry and Imaging Core for his assistance in Bio-Plex data collection and analysis.Doublecortin-like kinase 1 (Dclk1), a microtubule-associated kinase, marks the fifth lineage of intestinal epithelial cells called tuft cells that function as tumor stem cells in Apc mutant models of colon cancer. In order to determine the role of Dclk1 in dextran sulfate sodium (DSS) induced colonic inflammation both intestinal epithelial specific Dclk1 deficient (VillinCre;Dclk1f/f) and control (Dclk1f/f) mice were fed 3% DSS in drinking water for 9 days, allowed to recover for 2 days, and killed. The clinical and histological features of DSS-induced colitis were scored and immunohistochemical, gene expression, pro-inflammatory cytokines/chemokines, and immunoblotting analyses were used to examine epithelial barrier integrity, inflammation, and stem and tuft cell features. In DSS-induced colitis, VillinCre;Dclk1f/f mice demonstrated exacerbated injury including higher clinical colitis scores, increased epithelial barrier permeability, higher levels of pro-inflammatory cytokines and chemokines, decreased levels of Lgr5, and dysregulated Wnt/b-Catenin pathway genes. These results suggest that Dclk1 plays an important role in regulating colonic inflammatory response and colonic epithelial integrity.Yeshttp://www.plosone.org/static/editorial#pee

Dietary Pectin Increases Intestinal Crypt Stem Cell Survival following Radiation Injury

This research was performed as a project of the Intestinal Stem Cell Consortium, a collaborative research project funded by the National Institute of Diabetes and Digestive and Kidney Diseases (NIH U01 DK-085508 to CWH), and a grant from Oklahoma Center for the Advancement of Science and Technology to CWH.Gastrointestinal (GI) mucosal damage is a devastating adverse effect of radiation therapy. We have recently reported that expression of Dclk1, a Tuft cell and tumor stem cell (TSC) marker, 24h after high dose total-body gamma-IR (TBI) can be used as a surrogate marker for crypt survival. Dietary pectin has been demonstrated to possess chemopreventive properties, whereas its radioprotective property has not been studied. The aim of this study was to determine the effects of dietary pectin on ionizing radiation (IR)-induced intestinal stem cell (ISC) deletion, crypt and overall survival following lethal TBI. C57BL/6 mice received a 6% pectin diet and 0.5% pectin drinking water (pre-IR mice received pectin one week before TBI until death; post-IR mice received pectin after TBI until death). Animals were exposed to TBI (14 Gy) and euthanized at 24 and 84h post-IR to assess ISC deletion and crypt survival respectively. Animals were also subjected to overall survival studies following TBI. In pre-IR treatment group, we observed a three-fold increase in ISC/crypt survival, a two-fold increase in Dclk1+ stem cells, increased overall survival (median 10d vs. 7d), and increased expression of Dclk1, Msi1, Lgr5, Bmi1, and Notch1 (in small intestine) post-TBI in pectin treated mice compared to controls. We also observed increased survival of mice treated with pectin (post-IR) compared to controls. Dietary pectin is a radioprotective agent; prevents IR-induced deletion of potential reserve ISCs; facilitates crypt regeneration; and ultimately promotes overall survival. Given the anti-cancer activity of pectin, our data support a potential role for dietary pectin as an agent that can be administered to patients receiving radiation therapy to protect against radiation-induces mucositis.Yeshttp://www.plosone.org/static/editorial#pee

The effect of transitioning from a rearfoot strike to a non-rearfoot strike on running impulses per step

Over 19 million people consistently run as a form of exercise in the United States alone. Annually, approximately 50% of these runners will experience an injury detrimental to performance. A recent approach to mitigating running injuries is modification of a runner’s foot strike pattern (FSP). Transitioning runners from a rearfoot strike (RFS) to a non-rearfoot strike (NRFS) pattern has been shown to influence several factors related to running injuries, to include a reduction in average vertical loading rate (AVLR). This idea is well established, but there are likely other factors influencing running related injuries, such as running cadence and different impulses during each stance phase. The purpose of this study was to analyze the effect of a transitional NRFS running program on the magnitude of impulse per step. We hypothesized that impulse per step will decrease in the vertical, anterior, and posterior directions following the running program due to increased cadence. We hypothesized that medial and lateral impulses will remain unchanged after the treatment protocol

Comparison of On-Shoe Wireless Sensor to Instrumented Treadmill and Outdoor Environment – A Pilot Study

This study compared the MilestonePod (MSP) wireless running sensor to a fully instrumented treadmill (FIT) in measuring average vertical loading rate (AVLR), ground contact time (GCT), cadence, and stride length. MSP data from treadmill was also compared to MSP data during outdoor overground running. The MSP accurately measured GCT, cadence, and stride length during treadmill running compared to the FIT but failed to provide accurate AVLR data

The Effect of Running Foot Strike Transition on Impulse per Kilometer

Transitioning runners from a rearfoot strike (RFS) to a non-rearfoot strike (NRFS) pattern has been shown to influence several factors related to running injuries, to include a reducing average vertical loading rate [1]. However there are likely other factors influencing running related injuries, one potential element being total impulse. The purpose of this study was to analyze the effect of a transitional NRFS running program on impulses per unit distance. We hypothesized that impulse per unit distance will remain constant following a running transition program

Deletion of Dclk1 increases epithelial apoptosis and decreases epithelial proliferation following DSS treatment.

<p><b>A.</b> Apoptotic cells (Green) identified by TUNEL assay; <b>B.</b> Proliferative cells identified by immunostaining with anti-Ki67 antibody.</p

Immunohistochemical staining of β-Catenin in colon tissues following DSS treatment.

<p>The expression of β-Catenin (Brown) was identified by immunostaining with anti- β-Catenin antibody. Increased expression and increased nuclear localization of β-Catenin were found in Villin^Cre;Dclk1^f/f relative to Dclk1^f/f mice. Alcian blue was used for counterstaining.</p

Primer sequences for genes analyzed by real-time RT-PCR.

<p>Primer sequences for genes analyzed by real-time RT-PCR.</p

Epithelial deletion of Dclk1 upregulates pro-inflammatory cytokines and chemokines after DSS treatment.

<p><b>A.</b> Heatmap of Bio-Plex Pro Mouse Cytokine 23-Plex Assay results. <b>B</b>. The individual expression levels of structural cytokines, IL-1α, IL-1β, IL-10, and IL17. <b>C</b>. The individual expression levels of chemokines, Cxcl1, Ccl2, Ccl3, and Ccl5.</p