Prevalence and risk factors of running-related injuries in Korean non-elite runners: a cross-sectional survey study.

BACKGROUND: Due to the lack of consensus definition of running-related injuries, the prevalence and incidence of running-related injuries had been reported to vary between 19% and 92%. Moreover, the epidemiology of running-related injuries in Asian populations has been rarely investigated. The purpose of this study was to use the consensus definition of running-related injuries and investigate the epidemiology of running-related injuries in a Korean population. METHODS: Using the cross-sectional design, an online survey was circulated among various running communities in Korea. The questionnaire contained information on the presence and location of pain attributed to running, demographic characteristics, weekly running mileage, participation in high-intensity training, running pace, the longest running event participated, the type of shoes, foot strike, the reason for running, and exercise experience prior to running. RESULTS: Among 1046 runners (male=624, female=422) who responded, 94.7% experienced pain while running, but only 37% were categorized as having running-related injuries. The most common site of injury was the knee followed by the ankle. Exercise experience prior to running (OR=1.57 95% CI: 1.13-2.21), setting specific running goals (OR=1.57 95% CI: 1.08-2.27), increases in weekly running mileage (OR=1.66 95% CI: 1.05-2.62), and the longest running event participated (OR=2.15 95% CI: 1.22-4.05) were associated with significant increases in running-related injuries. CONCLUSIONS: To avoid running-related injuries, runners should be careful when increasing weekly mileage. Moreover, runners with previous exercise experience may need to approach running more cautiously. Setting goals and pursuing longer-distance running events may be motivating, but at the same time, can increase the risk of running-related injuries.

Heat shock protein 90 inhibitor attenuates renal fibrosis through degradation of transforming growth factor-ß type II receptor.

The accumulation of extracellular matrix proteins in the interstitial area is the final common feature of chronic kidney diseases. Accumulating evidence suggests that transforming growth factor (TGF)-ß1 promotes the development of renal fibrosis. Heat shock protein (Hsp) 90 inhibitors have been shown to repress TGF-ß1 signaling, but whether they inhibit renal fibrosis is unknown. The purpose of this study is to determine the therapeutic efficacy of Hsp90 inhibitor on renal fibrosis. In TGF-ß1-treated HK2 cells and unilateral ureteral obstruction (UUO) kidneys, we found that 17-allylamino-17-demethoxygeldanamycin (17AAG), an Hsp90 inhibitor, decreased the expression of α-smooth muscle actin, fibronectin, and collagen I and largely restored the expression of E-cadherin. 17AAG inhibited TGF-ß1-mediated phosphorylation of Smad2, Akt, glycogen synthase kinase-3ß, and extracellular signal-regulated kinase in HK2 cells. Inhibition of Hsp90 also blocked TGF-ß1-mediated induction of snail1. This 17AAG-induced reduction was completely restored by simultaneous treatment with proteasome inhibitor MG132. Furthermore, 17AAG blocked the interaction between Hsp90 and TGF-ß type II receptor (TßRII) and promoted ubiquitination of TßRII, leading to the decreased availability of TßRII. Smurf2-specific siRNA reversed the ability of 17AAG to inhibit TGF-ß1 signaling. The effect of 17AAG on TßRII expression and renal fibrosis was confirmed in UUO kidneys. These findings suggest that Hsp90 inhibitor prevents the development of renal fibrosis via a mechanism dependent on Smurf2-mediated degradation of TßRII.