Mauricio Castro-Sepulveda

Verified

Mauricio verified their affiliation via an institutional email.

Learn more

Verified

Mauricio verified their affiliation via an institutional email.

Learn more

• PhD in Medical Science
• PostDoc Position at University of Lausanne

In humans, insulin resistance has been linked to an impaired metabolic transition from fasting to feeding (metabolic flexibility; MetFlex). Previous studies suggest that mitochondrial dynamics response is a putative determinant of MetFlex; however, this has not been studied in humans. Thus, the aim of this study was to investigate the mitochondrial...

Mitochondria-endoplasmic/sarcoplasmic reticulum (ER/SR) interaction and mitochondrial fusion/fission are critical processes that influence substrate oxidation. This narrative review summarizes the evidence on the effects of substrate availability on mitochondrial-SR interaction and mitochondria fusion/fission dynamics to modulate substrate oxidatio...

Murine models lacking CLOCK/BMAL1 proteins in skeletal muscle (SkM) present muscle deterioration and mitochondria abnormalities. It is unclear whether humans with lower levels of these proteins in the SkM have similar alterations. Here we evaluated the association between BMAL1 and CLOCK protein mass with mitochondrial dynamics parameters and molec...

Aim: The present study aimed to investigate the effects of a single bout of resistance exercise on mitophagy in human skeletal muscle (SkM). Methods: Eight healthy men were recruited to complete an acute bout of one-leg resistance exercise. SkM biopsies were obtained one hour after exercise in the resting leg (Rest-leg) and the contracting leg (Ex...

The physical connection between mitochondria and endoplasmic reticulum (ER) is an essential signalinghub to ensure organelle and cellular functions. In skeletal muscle, ER-mitochondria calcium (Ca2+) signalingis crucial to maintain cellular homeostasis during physical activity. High expression of BCL2L13, a memberof the BCL-2 family, was suggested...

Disruptions in both circadian clock and mitochondrial dynamics in the skeletal muscle (SkM) have been associated with insulin resistance and sarcopenia. Emerging evidence, in resting conditions and in response to metabolic challenges like exercise, suggests the intricate interplay between the circadian clock, mitochondrial dynamics and SkM function...

Protocol to measure spontaneous locomotion, graded exercise oxygen consumption, and cross-sectional area of skeletal muscle cells in zebrafish Skeletal muscle function and quality are strong indicators of metabolic health. Here, we present a protocol for skeletal muscle phenotyping in zebrafish. We describe steps to evaluate spontaneous locomotion,...

Skeletal muscle maximal oxidative capacity (ATPmax) is a key component of age‐related sarcopenia and muscle health. The contribution of mitochondrial morphology and electron transport chain supercomplex (SC) assemblies to ATPmax has yet to be determined in human muscle. ATPmax measured in vivo by ³¹phosphorus magnetic resonance spectroscopy in the...

Sarcopenia corresponds to a decrease in muscle mass and strength. CCL5 is a new myokine whose expression, along with the CCR5 receptor, is increased in sarcopenic muscle. Therefore, we evaluated whether CCL5 and CCR5 induce a sarcopenic-like effect on skeletal muscle tissue and cultured muscle cells. Electroporation in the tibialis anterior (TA) mu...

Introduction: Obesity, characterised by excess adipose tissue, is a major public health problem worldwide. Brown (BAT) and beige adipose tissue participate in thermogenesis through uncoupling protein 1 (UCP1). Polyphenols including those from Calafate (a native polyphenol-rich Patagonian berry), are considered as potential anti-obesity compounds du...

Desminopathy R350P is a human myopathy that is characterized by the progres-sive loss of muscle fiber organization. This results in the loss of muscle size, mo-bility, and strength. In desminopathy, inflammation affects muscle homeostasisand repair, and contributes to progressive muscle deterioration. Mitochondriamorphology was also suggested to af...

Background: Reactive oxygen species (ROS) regulate glucose metabolism (GM) in skeletal muscle by improving the translocation of GLUT4. Antioxidant supplementation could block this physiological effect, altering glucose signaling during exercise. However, there is limited evidence in humans on whether antioxidant intake affects GM. Therefore, we aim...

In skeletal muscle (SkM), a reduced mitochondrial elongate phenotype is associated with several metabolic disorders like type 2 diabetes mellitus (T2DM). However, the mechanisms contributing to this reduction in mitochondrial elongate phenotype in SkM have not been fully elucidated. It has recently been shown in a SkM cell line that toll-like recep...

Background Skeletal muscle is sensitive to bile acids (BA) because it expresses the TGR5 receptor for BA. Cholic (CA) and deoxycholic (DCA) acids induce a sarcopenia-like phenotype through TGR5-dependent mechanisms. Besides, a mouse model of cholestasis-induced sarcopenia was characterised by increased levels of serum BA and muscle weakness, altera...

Background: Skeletal muscle generates force and movements and maintains posture. Under pathological conditions, muscle fibers suffer an imbalance in protein synthesis/degradation. This event causes muscle mass loss and decreased strength and muscle function, a syndrome known as sarcopenia. Recently, our laboratory described secondary sarcopenia in...

The aim of this study was to compare the potential additional effect of chia flour, whey protein, and a placebo juice to resistance training on fat-free mass (FFM) and strength gains in untrained young men. Eighteen healthy, untrained young men underwent an 8-week whole-body resistance training program, comprising three sessions per week. Subjects...

Skeletal muscle is a key metabolic tissue that has been purported to be affected by omega-3 (n-3) polyunsaturated fatty acids (PUFAs). Although the mechanisms remain unclear, recent evidence has shown that these benefits may in part be mediated by the capacity of n-3 PUFAs to be incorporated into skeletal muscle membranes including mitochondrial me...

Scope Nonalcoholic fatty liver disease (NAFLD) has a high and growing prevalence globally. Mitochondria are fundamental in regulating cell energy homeostasis. Nevertheless, mitochondria control mechanisms can be exceeded in this context of energy overload. Damaged mitochondria worsen NAFLD progression. Diet and lifestyle changes are the main recomm...

The non-responders (NRs) after exercise training have been poorly studied in populations with morbid obesity. The purpose of this study was to determine the NR prevalence after 20 weeks of concurrent training of morbidly obese women with a high or low number of metabolic syndrome (MetS) risk factors. Twenty-eight women with morbid obesity participa...

An interaction between mitochondrial dynamics, physical activity levels, and COVID-19 severity has been previously hypothesized. However, this has not been tested. We aimed to compare mitochondrial morphology and cristae den- sity of PBMCs between subjects with non-severe COVID-19, subjects with se- vere COVID-19, and healthy controls. Additionally...

Loss of skeletal muscle (SkM) quality is associated with different clinical conditions such as aging, diabetes, obesity, cancer and heart failure. Nutritional research has focused on identifying naturally occurring molecules that mitigate the loss of SkM quality induced by a pathology or syndrome. In this context, although few human studies have be...

The role of mitofusin 2 (Mfn2) in the regulation of skeletal muscle (SM) mitochondria‐sarcoplasmic (SR) juxtaposition, mitochondrial morphology, mitochondrial cristae density (MCD), and SM quality has not been studied in humans. In in vitro studies, whether Mfn2 increases or decreases mitochondria‐SR juxtaposition remains controversial. Transmissio...

Pomegranate peel is an agro-industrial residue obtained after fruit processing, with no commercial fate. It has a high total polyphenol (TP) content, which makes it an attractive by-product for its reuse. Pomegranate peel extract (PPE) and its bioactive compounds have shown positive effects on obesity models. Effects on favoring mitochondrial bioge...

Electrical pulse stimulation (EPS) has been suggested to be a useful method to investigate the mechanisms underlying the adaptations of human skeletal muscle to both endurance and resistance exercise. Although different myotube stimulation protocols mimicking acute and chronic endurance exercise have been developed, no convincing protocol mimicking...

The micropeptide adropin encoded by the clock-controlled Energy homeostasis-associated gene is implicated in the regulation of glucose metabolism. However, its links to rhythms of nutrient intake, energy balance and metabolic control remains poorly defined. Using surveys of Gene Expression Omnibus datasets, we confirm that fasting suppresses liver...

Elevated free fatty acids (FFAs) impair beta cell function and reduce beta cell mass as a consequence of the lipotoxicity that occurs in type 2 diabetes (T2D). We previously reported that the membrane protein caveolin-1 (CAV1) sensitizes to palmitate-induced apoptosis in the beta pancreatic cell line MIN6. Thus, our hypothesis was that CAV1 knock-o...

Introduction: The purpose of this systematic review was to analyze the effect of plyometric jump training (PJT) applied in conjunction with tapering strategies on the jump performance of team-sport athletes. Evidence Acquisition: The meta-analysis included: randomized-controlled studies that incorporated a PJT program; cohorts of team-sport athlete...

β-hydroxybutyrate is the main ketone body generated by the liver under starvation. Under these conditions, it can sustain ATP levels by its oxidation in mitochondria. As mitochondria can modify its shape and function under different nutritional challenges, we study the chronic effects of β-hydroxybutyrate supplementation on mitochondrial morphology...

We aimed to determine whether basal concentrations of testosterone, cortisol or the ratio testosterone/cortisol were related to sweat Na + loss, sweat Na + concentration ([Na + ]) and sweat rate during exercise. Twenty-two female elite soccer players participated in the study. Testosterone and cortisol were measured in blood samples before exercise...

Objective This study aimed to determine the relationship between metabolic flexibility (MetFlex) measured during a euglycemic‐hyperinsulinemic clamp and a prolonged fast. This study also analyzed the association between MetFlex and metabolic health. Methods Eighteen healthy men (mean [SD]: 22 [2] years old; BMI: 22 [1] kg/m²) performed two session...

Background: Disturbances in skeletal muscle lipid oxidation might induce ectopic fat deposition and lipotoxicity. Nevertheless, the cellular mechanisms that regulate skeletal muscle lipid oxidation have not been fully determined. We aimed to determine whether there was an association between relative whole-body lipid oxidation with mitochondrial s...

Although the effects of high intensity interval training (HIIT) on health and sports performance are well documented, the effects of this training type on mucosal immune function remain unclear. The aim of this study was to assess the impact of an acute HIIT session on salivary immune and endocrine marker levels (immu-noglobulin A (sIgA), alpha amy...

Background: Hydration status affects endurance performance. Pre-exercise hydration recommendations target the consumption of high carbohydrate and sodium beverages. Milk, due to its carbohydrate and sodium content, may be considered an effective pre-exercise hydration beverage. Purpose: In a randomized cross-over trial, we compared the effects o...

During exercise, human body maintains optimal body temperature through thermoregulatory sweating, which implies the loss of water, sodium (Na+) and other electrolytes. Sweat rate and sweat Na+ concentration show high interindividual variability, even in individuals exercising under similar conditions. Testosterone and cortisol may regulate sweat Na...

In rodents’ dehydration induces anorexia, however in human the role of dehydration in energy intake is controversial. This study investigated the effect of extreme fluid restriction on acute energy intake during and after exercise-induced dehydration. Eight physically active participants performed two sessions of exercise to induce dehydration. Aft...

Background: Maximal voluntary isometric handgrip strength (MVIHS) is influenced by age, sex, and handedness. Aim: To assess the association of MVIHS with age, sex, and handedness in older adults. Material and Methods: MVIHS was measured using a digital dynamometer in 60 men and 60 women aged 73 ± 6 years. Weight, height and handedness were also rec...

A soccer match induce changes in physiological stress biomarkers as testosterone (T), cortisol (C), and testosterone:cortisol (T:C) ration. Hydration state may also modulate these hormones, and therefore may alter the anabolic/catabolic balance in response to exercise. The role of hydration status before the match in these biomarkers has not yet be...

Background: There are several predictive equations for estimating resting metabolic rate (RMR) in healthy humans. Concordance of these equations against measured RMR is variable, and often dependent on the extent of RMR. Part of the discrepancy may lie on an insufficient accuracy of metabolic carts, but this accuracy can be improved through a corr...

Background: Handgrip strength (HS) and peak oxygen consumption (Vo2peak) are powerful predictors of cardiovascular risk, although it is unknown which of the two variables is the better predictor. Aim: The objective of the following study was to relate HS and Vo2peak to cardiovascular risk markers in older Chilean women. Methods: Physically act...

Sarcopenia is the degenerative loss of muscle mass and strength with aging. Although a role of mitochondrial metabolism in muscle function and in the development of many diseases has been described, the role of mitochondrial topology and dynamics in the process of muscle aging is not fully understood. This work shows a time line of changes in both...

Purpose. The objective of this study was to compare the effects of a four-week intensified period of in-season soccer training with addition of explosive training and beta-hydroxy-beta-methylbutyrate (HMB) supplementation on maximal-intensity and endurance performance in young male soccer players, com-pared with a placebo (i.e., magnesium stearate)...

Background Muscle damage and dehydration are common during basketball matches, but their relationship with performance in this sport is unclear. The aim of this study was to correlate changes in muscle damage (creatine kinase), hydration status (Na+; K+; body mass), and lower body power (countermovement jump) occurring in young athletes during a ba...

Purpose: The aim of this study was to compare the changes in salivary cortisol and testosterone concentrations between men and women during an official volleyball tournament and to test potential correlations between changes in these hormones and perceived exertion after match. Methods: Three matches of each team were assessed in the group stage...

Handgrip strength (HS) and peak oxygen consumption (Vo2peak) are powerful predictors of cardiovascular risk, although it is unknown which of the two variables is the better predictor. AIM: The objective of the following study was to relate HS and Vo2peak to cardiovascular risk markers in older Chilean women. METHODS: Physically active adult women (...

Objective: To determine the influence of a gas exchange correction protocol on resting metabolic rate (RMR) and respiratory quotient (RQ) assessed by a Vmax Encore 29n metabolic cart in overnight fasted and fed humans; and to assess the predictive power of body size for corrected and uncorrected RMR . Methods: Healthy participants (23 M/29 F; 34±9...

BACKGROUND: Little evidence exists on which variables of body composition or muscular strength mediates more glucose control improvements taking into account inter-individual metabolic variability to different modes of exercise training. OBJECTIVE: We examined ‘mediators’ to the effects of 6-weeks of resistance (RT) or high-intensity interval trai...

Mitochondrial function relays on the balance between fusion and fission events that determine mitochondrial communication. Mutations of outer mitochondrial membrane (OMM) fusion protein Mfn2, cause motor neuron degeneration disease Charcot-Marie-Tooth Type 2 (CMT2). Also, Mfn2 plays a controversial role in the ER-mitochondrial communication. Thus,...

Background: The aim of this study was to assess the effects of three exercise training program in the adaptation of the heart rate recovery of patients with insulin resistance. Methods: We studied 43 women with insulin resistance, which were assigned to three training groups: i) high intensity interval training (HIT, age 39.0 ± 10 y), ii) streng...

Fluid and electrolyte status have a significant impact on physical performance and health. Pre-exercise recommendations cite the possibility of consuming beverages with high amounts of sodium. In this sense, non-alcoholic beer can be considered an effective pre-exercise hydration beverage. This double-blind, randomized study aimed to compare the ef...

This study aimed to evaluate and compare the hydration states prior to different sporting events (training sessions, friendly and official matches) in elite female soccer players and relate that to the importance that the player attached to the hydration state as a determinant of sports performance. The hydration state of 17 female elite soccer pla...

Introduction: childhood obesity is a worldwide health concern. For this issue different intervention have being planned to increase physical activity patterns and reduce the excess of weight in children with limited or no success. Objective: the aim of this study is to evaluate the results of a pilot intervention consisting in three 15-minute br...

Introduction: there is a lack of studies concerning hydration status before training in professional soccer player. Purpose: to describe hydration status before regular training practices in professional soccer players. Methods: a total of 156 male soccer players (age 25.4 ± 5.2 y) from six professional Chilean clubs were included. No hydratio...

Introducción: Existen pocos estudios relacionados con el estado de hidratación pre-entrenamiento en futbolistas profesionales. Objetivo: Determinar la prevalencia de deshidratación pre-entrenamiento en jugadores profesionales de fútbol. Métodos: Se incluyeron un total de 156 jugadores de fútbol (edad 25.4 ± 5.2 y) de seis clubes profesionales chil...

The aim of the study was to compare the effects of bilateral, unilateral, or combined bilateral and unilateral plyometric training (PT) on muscle power output, endurance and balance performance adaptations in young soccer players. Four groups of young soccer players (age 11.4 ± 2.2 y) were divided into: control (CG; n = 14), bilateral group (BG; n...

The purpose of this study was to determine the effects of short-term plyometric training interposed with 24 hours or 48 hours of rest between training sessions on explosive and endurance adaptations in young soccer players. A total of 166 players, between 10 and 17 years of age were randomly divided into 3 groups: control (CG; n=55), plyometric tra...

Dehydration has long been shown to reduce physical performance, cognitive function, and alertness in a range of athletic and non-athletic populations. The motor sport needs several perceptive and neuromuscular skills to adequately perform the race. Objectives.—Describe the hydration practices and dehydration prevalence in elite motor sport athletes...

The purpose of the study was to compare the effects of progressive volume-based overload to constant volume-based overload on muscle explosive and endurance performance adaptations during a bi-weekly short-term (i.e. six weeks) plyometric training intervention in young soccer players. Three groups of young soccer players (age 13.0 +/- 2.3 y) were d...

Introduction: Heart rate variability and resting metabolic rate are commonly to assess athlete ́s physiological status and energy requirements. Exercise-induced dehydration can reach up to 5% of body mass per hour. Consequently, dehydration may have a profound physiological effect on human’s homeostasis. Objectives: To compare the effects of dehydr...

Introduction Physical activity is an effective treatment for hypertension, but the training must be constant to maintain the adaptations. Objective To measure the effects of aerobic training and detraining on blood pressure of hypertensive women. Materials and methods Twelve hypertensive women underwent 2 weeks of aerobic training and 2 weeks of...

Background: Short term physical training programs may improve insulin resistance and hyperglycemia. Aim: To assess the effects of eight weeks of combined exercise program on serum lipids and glycemic level in women with hyperglycemia and hypercholesterolemia. Patients and Methods: Ten healthy women, nine women with hyperglycemia, ten with hyperchol...

Background: Short term physical training programs may improve insulin resistance and hyperglycemia. Aim: To assess the effects of eight weeks of combined exercise program on serum lipids and glycemic level in women with hyperglycemia and hypercholesterolemia. Patients and Methods: Ten healthy women, nine women with hyperglycemia, ten with hyperchol...

The purpose of this study was to determine the effects of short-term plyometric training interposed with 24 hours or 48 hours of rest between training sessions on explosive and endurance adaptations in young soccer players. A total of 166 players, between 10 and 17 years of age were randomly divided into 3 groups: control (CG; n=55), plyometric tra...