Browsing by Author "Penailillo, Luis"

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    Is the Rotatory Knee Stability Immediately Decreased Following a Competitive Soccer Match?
    (2022) Neira, Alejandro; Silvestre, Rony; Debandi, Anibal; Darras, Daniel; Cristi-Sanchez, Iver; Barra, Ignacio; Penailillo, Luis; De La Fuente, Carlos
    Fatigue induced by soccer playing increases physical efforts, which might alter the transverse knee stability, a known factor that promotes knee injuries, particularly anterior cruciate ligament injury. Thereby, primarily, we aimed to determine whether rotatory knee stability decreases immediately following a competitive soccer match in amateur players. Furthermore, we assessed the role of the preferred and non-preferred limbs to kick a ball in rotatory knee stability and the correlation between performance parameters and rotatory knee stability. We hypothesized that the knee stability decreases immediately after a competitive soccer match in amateur players. Eight healthy amateur soccer players (aged 27.2 +/- 4.7 years and with body mass index of 23.8 +/- 1.2 kg m(-2)) were included immediately before and after a competitive soccer match. The rotatory knee stability was assessed in the preferred and non-preferred limbs through the acceleration and jerk of the pivot shift maneuver and by the internal knee rotation of a pivoting landing task. Two-way repeated-measures ANOVA for factors time (before and after the soccer match) and limb (preferred and non-preferred) and multiple comparisons were performed using alpha = 5%. There was a statistical significance for the main factor time in the acceleration (5.04 vs. 6.90 ms(-2), Delta = 1.86 ms(-2), p = 0.020, eta(2) = 0.331) and jerk (18.46 vs. 32.10 ms(-2), Delta = 13.64 ms(-2), p = 0.004, eta(2) = 0.456) of the pivot shift maneuver. Rotatory stability decreases following a competitive soccer match in amateur soccer players under fatigue. Both the acceleration and jerk during the pivot shift maneuver is increased without significant internal knee rotation changes during the pivoting landing task.
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    Role of the ubiquitin-proteasome system in the sarcopenic-like phenotype induced by CCL5/RANTES
    (2024) Conejeros-Lillo, Sabrina; Aguirre, Francisco; Cabrera, Daniel; Simon, Felipe; Penailillo, Luis; Cabello-Verrugio, Claudio
    Sarcopenia is characterized by reduced muscle strength and mass, and a decline in muscle fiber diameter and amount of sarcomeric proteins. Sarcopenia involves the activation of the ubiquitinproteasome system (UPS). MuRF-1 and atrogin-1 are E3 ubiquitin ligases belonging to UPS, leading to proteolysis mediated by the PSMB 5, 6, and 7 subunits of 20S proteasome. CCL5/RANTES induces a sarcopenic-like effect in muscle cells. The present work explored the impact of CCL5 on UPS components and the influence of UPS on its sarcopenic-like effect. We demonstrated that CCL5 increased MuRF-1 and atrogin-1 protein levels and mRNA levels of subunits PSMB 5, 6, and 7. We used the MG132 inhibitor to elucidate the role of the 20S proteasome in the CCL5-induced sarcopenic-like effect. This inhibitor prevented the decrease in troponin and MHC protein levels and partially stopped the reduction in the diameter of singleisolated flexor digitorum brevis (FDB) muscle fibers induced by CCL5. These findings indicate that CCL5 actively modulates the UPS. Moreover, our results show the direct participation of UPS in the sarcopenic-like phenotype induced by CCL5.