REJUVENATION RESEARCH Volume 14, Number 3, 2011 ª Mary Ann Liebert, Inc. DOI: 10.1089/rej.2010.1132 An Exploratory Analysis of the Effects of a Weight Loss Plus Exercise Program on Cellular Quality Control Mechanisms in Older Overweight Women Stephanie E. Wohlgemuth,1 Hazel A. Lees,1 Emanuele Marzetti,1,2 Todd M. Manini,1 Juan M. Aranda,3 Michael J. Daniels,4 Marco Pahor,1 Michael G. Perri,5 Christian Leeuwenburgh,1 and Stephen D. Anton1,5 Abstract Obese older adults are particularly susceptible to sarcopenia and have a higher prevalence of disability than their peers of normal weight. Interventions to improve body composition in late life are crucial to maintaining independence. The main mechanisms underlying sarcopenia have not been determined conclusively, but chronic inflammation, apoptosis, and impaired mitochondrial function are believed to play important roles. It has yet to be determined whether impaired cellular quality control mechanisms contribute to this process. The objective of this study was to assess the effects of a 6-month weight loss program combined with moderate-intensity exercise on the cellular quality control mechanisms autophagy and ubiquitin-proteasome, as well as on inflammation, apoptosis, and mitochondrial function, in the skeletal muscle of older obese women. The intervention resulted in significant weight loss (8.0 Æ 3.9 % vs. 0.4 Æ 3.1% of baseline weight, p ¼ 0.002) and improvements in walking speed (reduced time to walk 400 meters, À 20.4 Æ 16% vs. À 2.5 Æ 12%, p ¼ 0.03). In the intervention group, we observed a three-fold increase in messenger RNA (mRNA) levels of the autophagy regulators LC3B, Atg7, and lysosome-associated membrane protein-2 (LAMP-2) compared to controls. Changes in mRNA levels of FoxO3A and its targets MuRF1, MAFBx, and BNIP3 were on average seven-fold higher in the intervention group compared to controls, but these differences were not statistically significant. Tumor necrosis factor-a (TNF-a) mRNA levels were elevated after the intervention, but we did not detect significant changes in the downstream apoptosis markers caspase 8 and 3. Mitochondrial biogenesis markers (PGC1a and TFAm) were increased by the intervention, but this was not accompanied by significant changes in mitochondrial complex content and ac- tivity. In conclusion, although exploratory in nature, this study is among the first to report the stimulation of cellular quality control mechanisms elicited by a weight loss and exercise program in older obese women. Introduction involuntary loss of muscle mass and function), and the combination of muscle loss and fat gain may act synergisti- ver the past decade, the prevalence of obesity in older cally to increase the risk of adverse health outcomes, in- Oadults in the United States has doubled.1 Recent esti- cluding disability7 and mortality.8 The pathogenesis of mates indicate that more than 35% of Americans over the age sarcopenic obesity is probably linked to the progressive de- of 60 are obese,1 and therefore are at increased risk for a cline in total energy expenditure resulting from the ‘‘physi- number of health conditions, including cardiovascular dis- ologic’’ age-related muscle mass decline, decreased physical ease (CVD), diabetes, hypertension, dyslipidemia, asthma, activity, and reduced basal metabolic rate, in the face of in- osteoarthritis, and several cancers.2–6 In addition, obese creased or stable caloric intake.9 The accumulation of adi- elderly are particularly susceptible to sarcopenia (the pose tissue, in turn, aggravates muscle wasting via increased 1Department of Aging and Geriatrics, Institute on Aging, College of Medicine, University of Florida, Gainesville, Florida. 2Department of Orthopaedics and Traumatology, Catholic University of the Sacred Heart, Rome, Italy. 3Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida. 4Department of Statistics, College of Liberal Arts and Sciences, University of Florida, Gainesville, Florida. 5Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, Gainesville, Florida. 315 316 WOHLGEMUTH ET AL. secretion of catabolic cytokines (e.g., tumor necrosis factor-a cise and diet intervention has yet to be determined. If similar [TNF-a] and interleukin-6 [IL-6]), reduced insulin sensitivity biological changes occur in older adults, then improvements and decreased incretion of anabolic hormones (e.g., growth in mitochondrial function may be another mechanism hormone [GH], insulin-like growth factor-1 [IGF-1], and through which weight loss plus exercise interventions may testosterone). In addition, intermuscular fat infiltration may ameliorate physical function and reduce functional decline in distort muscle architecture, further contributing to the loss of the overweight elderly. muscle strength.10 Therefore, the purpose of the present study was to assess Lifestyle-based interventions may attenuate muscle loss in the skeletal muscle of older, overweight women the im- and improve body composition in obese, older adults, but an pact of a weight loss plus exercise intervention on markers of optimal method has yet to be established. Caloric restriction autophagy, components of the UPS, as well as markers of (i.e., a caloric deficit of 500–1,000 kcal/day below the steady inflammation, apoptosis, and mitochondrial biogenesis and state) is generally required to achieve significant weight loss. function. We hypothesized that the combination of dietary Diet-induced weight loss, however, typically leads to a de- restriction and exercise would stimulate cellular quality crease of fat-free mass, a significant concern for older adults. control processes (specifically autophagy and components of In contrast, exercise interventions may increase muscle mass, the ubiquitin proteasome pathway), attenuate inflammation improve muscle quality,11,12 and increase muscle protein and apoptosis, and improve mitochondrial function. We also synthesis,13 but rarely produce significant weight loss unless hypothesized that the physical performance of individuals individuals engage in very high amounts of moderate or participating in the weight loss plus exercise intervention vigorous activity.14 Therefore, the challenge for clinicians would be improved. and researchers working with overweight elderly is to design lifestyle-based interventions that can produce significant Materials and Methods weight loss while avoiding (or limiting) the loss of fat-free Participants mass.15 It is generally believed that weight loss improves physical This study was approved by the University of Florida’s function by indirectly benefiting the musculoskeletal sys- Institutional Review Board. Participants selected for this tem.2,16 Additional biological processes, however, may in- exploratory study were a subset of a larger-scale, random- fluence the relationship between weight loss and ized, controlled trial. Participants of this larger randomized improvements in physical function in late life. The impor- controlled trial were community-dwelling, sedentary, over- tance of cellular quality control, accomplished by the inter- weight, African-American and Caucasian women with mild play between autophagy and the ubiquitin–proteasome to moderate functional limitations. Eligibility requirements system (UPS), has recently been reviewed.17,18 The decline in included: age between 55 and 79 years, body mass index autophagic and proteasomal activity observed during aging (BMI) >29 kg/m2, sedentary lifestyle (defined as <20 min/ has been proposed to contribute to different aspects of age- week of aerobic exercise), and mild to moderate functional related phenotypes, such as neurodegeneration, osteoarthri- impairment, as defined by a Short Physical Performance tis, declining liver and T cell function, as well as age-related Battery (SPPB) summary score of 4–10.28 Eligible individuals muscle loss.19–23 It is noteworthy that caloric restriction and were excluded if their medical history, clinical examination, exercise increase the activity and effectiveness of autophagy or laboratory results revealed any of the following condi- and the UPS.24,25 Recently, we conducted a preclinical study tions: Weight >300 pounds (136 kg), weight loss >10 in which autophagy was assessed in the skeletal muscle of pounds (4.5 kg) in the past 6 months, history of surgery for young and old rats that were either fed ad libitum and sed- weight loss, hospitalization within the past 6 months, sig- entary or mildly calorie restricted and exercised. Markers of nificant diseases likely to limit life span and/or increase risk autophagy were decreased in the old, sedentary, ad libitum- of intervention (i.e., coronary heart disease; chronic or re- fed rats, but were upregulated in the old, calorie-restricted, current respiratory or gastrointestinal conditions; cancer and exercising rats. This increase was accompanied by an [except nonmelanoma skin cancer] within 5 years or active attenuation of skeletal muscle apoptosis.22 However, the ef- cancer treatment, fasting blood glucose >110 mg/dL, rest- fects of a moderate weight loss plus exercise intervention in ing blood pressure >160/90 mmHg), or musculoskeletal or overweight older adults on cellular quality control mecha- neurological conditions that would preclude walking on a nisms in skeletal muscle have yet to be elucidated. regular basis. Potential participants were also excluded if Energy production by healthy mitochondria is equally as they reported taking any of the following