Mitochondrial Alterations in PINK1 Deficient Cells Are Influenced by Calcineurin-Dependent Dephosphorylation of Dynamin-Related Protein 1

PTEN-induced novel kinase 1 (PINK1) mutations are associated with autosomal recessive parkinsonism. Previous studies have shown that PINK1 influences both mitochondrial function and morphology although it is not clearly established which of these are primary events and which are secondary. Here, we describe a novel mechanism linking mitochondrial dysfunction and alterations in mitochondrial morphology related to PINK1. Cell lines were generated by stably transducing human dopaminergic M17 cells with lentiviral constructs that increased or knocked down PINK1. As in previous studies, PINK1 deficient cells have lower mitochondrial membrane potential and are more sensitive to the toxic effects of mitochondrial complex I inhibitors. We also show that wild-type PINK1, but not recessive mutant or kinase dead versions, protects against rotenone-induced mitochondrial fragmentation whereas PINK1 deficient cells show lower mitochondrial connectivity. Expression of dynamin-related protein 1 (Drp1) exaggerates PINK1 deficiency phenotypes and Drp1 RNAi rescues them. We also show that Drp1 is dephosphorylated in PINK1 deficient cells due to activation of the calcium-dependent phosphatase calcineurin. Accordingly, the calcineurin inhibitor FK506 blocks both Drp1 dephosphorylation and loss of mitochondrial integrity in PINK1 deficient cells but does not fully rescue mitochondrial membrane potential. We propose that alterations in mitochondrial connectivity in this system are secondary to functional effects on mitochondrial membrane potential

A COMPARISON OF SKINFOLDS TO DUAL ENERGY X-RAY ABSORPTIOMETRY FOR BODY COMPOSITION ANALYSIS IN DIVISON 1 COLLEGIATE BASKETBALL PLAYERS

Chelsey R. Gegg1, Jeremy T. Barnes1, Jason D. Wagganer1, Jeremy P. Loenneke2, William M. Miller3, Dhwani S. Soni1 & Ryan J. Johnson1. 1Southeast Missouri State University, Cape Girardeau, MO; 2University of Mississippi, University, MS; 3 University of Central Missouri, Warrensburg, MO; e-mail: [email protected] Body composition (BC) is a frequently assessed component of fitness in Division 1 collegiate athletes. Many different field methods are used to estimate BC but bioelectrical impedance analysis (BIA) or skinfolds (SKF) are typically utilized due to cost and ease of use. PURPOSE: The purpose of this study was to determine the validity of the SKF method compared to dual-energy X-ray absorptiometry (DXA) for estimating percent body fat (%fat) in Division 1collegiate basketball players. METHODS: Participants’ %fat was estimated using the SKF method at the three sites recommended by Jackson and Pollock for males (thigh, abdomen and chest) and females (thigh, suprailiac, and triceps) compared to DXA, which served as the criterion estimate. Participants were 13 female and 11 male Division 1 collegiate basketball players age 19 (1) yrs., height 1.83 (0.14) m., body mass 81.1 (13.9) kg, and BMI 24.4 (3.9) kg/m2. RESULTS: The validity of the SKF %fat estimate was based on a comparison to the criterion value from the DXA by calculating the mean, SD, coefficient of determination (r2), and standard error of estimate (SEE) from linear regression analysis. To assess the average deviation of individual scores from the line of identity, total error (TE) was calculated for the SKF estimate. A paired sample t-test determined paired-wise differences between measurements using an alpha level of 0.05. The mean %fat results were as follows: SKF [17 (10) %] and DXA [20 (11) %]. Significantly different means were observed for SKF (3%fat, p£0.001) when compared to DXA. The r2 value was .918; the SEE was 3.4 %fat; and total error (TE) value was 4.4 %fat. The results were similar when separated by sex. CONCLUSIONS: In this study, the SKF estimate did not provide a valid estimate of body composition and underestimated %fat compared to the DXA estimate. Thus, the results suggest that SKF may not provide a valid estimate of %fat in Division 1 collegiate basketball players

BIOELECTRICAL IMPEDANCE ANALYSIS VERSUS SKINFOLD CALIPERS BODY FAT PERCENTAGE MEASUREMENTS IN AMERICAN FOOTBALL PLAYERS

Michelle L. OtteƗ1, Lucas K. ShrumƗ1, Kelly D. BarnsƗ1, Kurt W. McDowellǂ1, Chelsey R. Geggǂ1, Ryan D. Napoliǂ1, Ryan J. Johnsonǂ1, Jeremy T. Barnesǂ1, Thomas J. Pujolǂ1, FACSM, & Jason D. Wagganerǂ1, 1Southeast Missouri State University, Cape Girardeau, MO Bioelectrical impedance (BIA) and skinfold (SKF) measurements are commonly used to assess body fat percentage (BF%) (i.e., fat vs. lean mass). There are many different quick and cost efficient methods of estimating body fat via BIA (i.e., hand held equipment such as the OMRON Fat Loss Monitor HBF-306C) or SKF (i.e., Lange SKF calipers). BIA and SKF calipers report similar accuracy ranges (i.e., +3.5%) if used by a trained technician and the subject has a normal hydration status. Other factors that can affect the accuracy of SKF assessments include lack of training and poor technique, incorrect site location, and/or an overly obese or extremely lean participant. Both methods of measurement are used in various field settings such as collegiate athletics due to reliability, ease of use, and affordability. PURPOSE: The purpose of this study was to compare college-aged American Football players BF% as measured by the OMRON Fat Loss Monitor HBF-306C compared to that estimated using Lange SKF calipers and the Jackson and Pollock formula. METHODS: Each participant (male=88; age=19.78+1.30 yrs; wt=105.82+22.82 kg; ht=183.67+6.20 cm) had BF% assessed, in the early morning, via the OMRON Fat Loss Monitor HBF-306C (in the Athletic mode) in the standing position. Body density was calculated based on measurements taken at three sites (i.e., chest, abdominal and thigh) using Lange SKF calipers. Then an ethnically appropriate equation was used to convert body density to body fat percent. RESULTS: A paired samples t-test indicated the OMRON Fat Loss Monitor HBF-306C BF% (18.50+6.50) was significantly higher than the Lange SKF calipers BF% (16.81+6.74) (p=.001). CONCLUSIONS: While the two modes of BF% were significantly different, they were within the manufacturer stated accuracy range. While the exact reason for this difference is unknown, some factors could be related to the bilateral (i.e., both hands) measurement via BIA compared to the unilateral (i.e., right side only) measurements taken by the calipers, hydration status, extremely high or low body fat, and/or human error. More research needs to be done comparing different modes of BF% amongst an athletic population

Availability of a sports dietitian may lead to improved performance and recovery of NCAA division I baseball athletes

Abstract Background The purpose was to survey dietary habits (DH) and nutrient timing (NT) practices of baseball student-athletes (mean ± SD; 20.7 ± 1.4 yr.) from three NCAA Division I institutions, and examine the effect of a sports dietitian (SD) in regard to nutrition practices. Methods Descriptive statistics and Pearson X 2 analyses were run. Responses on 10 DH and 5 NT items differed (p ≤ 0.10) between athletes who sought dietary planning from a SD (n = 36) versus those who consulted a strength and conditioning coach (SCC, n = 42). Results In regard to DH items, the SD group found it easier to eat before activity (92% vs. 71%, p = 0.03), did not consume fast food (31% vs. 14%, p = 0.02), caffeinated beverages (57% vs. 46%, p = 0.02), or soda (56% vs. 37%, p = 0.10), prepared their own meals more often (86% vs. 73%, p = 0.07), and took daily multi-vitamins (56% vs. 32%, p = 0.02). The SCC group ate more at burger locations (21% vs. 6%, p = 0.02). In regard to NT items, the SD group ate breakfast before training/lifting sessions (67% vs. 37%, p = 0.02), and had post-workout nutrition options provided (61% vs. 27%, p = 0.01). The SCC group reported pre-competition meals of fast food (58% vs. 45%, p = 0.01), and sport coaches who were less aware of healthy food options (39% vs. 65%, p = 0.05). Conclusions The SD is as a valuable asset to an intercollegiate athletics program. In the current study, athletes from the SD group consumed less high calorie/low nutrient dense items, ate before exercise, and consumed healthier options post-exercise. The presence of a SD was linked to provision of healthier food options during team trips. The evidence-based eating strategies and dietary plan provided by a SD may lead to improved performance and recovery