Mitochondrial dysfunction in human skeletal muscle biopsies of lipid storage disorder

ABSTRACT Oritavancin, a semisynthetic derivative of vancomycin endowed with a cationic amphiphilic character, accumulates to large extent in the lysosomes of eukaryotic cells (F. Van Bambeke, S. Carryn, C. Seral, H. Chanteux, D. Tyteca, M. P. Mingeot-Leclercq, and P. M. Tulkens, Antimicrob. Agents Chemother. 48:2853-2860, 2004). In the present study, we examined whether this accumulation could cause cell alterations in phagocytic (J774 mouse macrophages) and nonphagocytic (rat embryo fibroblasts) cells exposed to clinically meaningful (0- to 40-mg/liter) concentrations of oritavancin. Optical and electronic microscopy evidenced conspicuous alterations of the vacuolar apparatus in both cell types, characterized by the deposition of concentric lamellar structures, finely granular material, or other less-defined osmiophilic material, often deposed in giant vesicles. Biochemical studies showed an accumulation of phospholipids (1.5× control values) and free and esterified cholesterol (3 to 4× control values for total cholesterol). Accumulation of these lipids was in close relation to that of oritavancin (excess phospholipid/oritavancin and excess cholesterol/oritavancin molar ratios of 2 to 3 and 3 to 5, respectively). Cholesterol accumulation was rapid and reversible, and that of phospholipids was slower and poorly reversible. Vancomycin and teicoplanin, used as controls (50 and 100 mg/liter, respectively), did not cause any significant change in the lipid content of fibroblasts. The data therefore suggest that oritavancin has the potential to cause a mixed-lipid storage disorder in eukaryotic cells.

Download Full-text

Pro- and macroglycogenolysis: relationship with exercise intensity and duration

Journal of Applied Physiology ◽

10.1152/jappl.2001.90.3.873 ◽

2001 ◽

Vol 90 (3) ◽

pp. 873-879 ◽

Cited By ~ 33

Author(s):

T. E. Graham ◽

K. B. Adamo ◽

J. Shearer ◽

I. Marchand ◽

B. Saltin

Keyword(s):

Skeletal Muscle ◽

Metabolic Regulation ◽

Human Skeletal Muscle ◽

Exercise Period ◽

Group 3 ◽

Group 2 ◽

Male Subjects ◽

Muscle Biopsies ◽

Over Time ◽

Group 1

We examined the net catabolism of two pools of glycogen, proglycogen (PG) and macroglycogen (MG), in human skeletal muscle during exercise. Male subjects ( n = 21) were assigned to one of three groups. Group 1 exercised 45 min at 70% maximal O2 uptake (V˙o 2 max) and had muscle biopsies at rest, 15 min, and 45 min. Group 2 exercised at 85%V˙o 2 max to exhaustion (45.4 ± 3.4 min) and had biopsies at rest, 10 min, and exhaustion. Group 3 performed three 3-min bouts of exercise at 100%V˙o 2 max separated by 6 min of rest. Biopsies were taken at rest and after each bout. Group 1 had small MG and PG net glycogenolysis rates (ranging from 3.8 ± 1.0 to 2.4 ± 0.6 mmol glucosyl units · kg−1 · min−1) that did not change over time. In group 2, the MG glycogenolysis rate remained low and unchanged over time, whereas the PG rate was initially elevated (11.3 ± 2.3 mmol glucosyl units · kg−1 · min−1) and declined ( P ≤ 0.05) with time. During the first 10 min, PG concentration ([PG]) declined ( P ≤ 0.05), whereas MG concentration ([MG]) did not. Similarly, in group 3, in both the first and the second bouts of exercise [PG] declined ( P ≤ 0.05) and [MG] did not, although by the end of the second exercise period the [MG] was lower ( P ≤ 0.05) than the rest level. The net catabolic rates for PG in the first two exercises were 22.6 ± 6.8 and 21.8 ± 8.2 mmol glucosyl units · kg−1 · min−1, whereas the corresponding values for MG were 17.6 ± 6.0 and 10.8 ± 5.6. The MG pool appeared to be more resistant to mobilization, and, when activated, its catabolism was inhibited more rapidly than that of PG. This suggests that the metabolic regulation of the two pools must be different.

Download Full-text

The Mitochondrial Proteomic Signatures of Human Skeletal Muscle Linked to Insulin Resistance

International Journal of Molecular Sciences ◽

10.3390/ijms21155374 ◽

2020 ◽

Vol 21 (15) ◽

pp. 5374 ◽

Cited By ~ 1

Author(s):

Rikke Kruse ◽

Navid Sahebekhtiari ◽

Kurt Højlund

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Mitochondrial Dysfunction ◽

Human Skeletal Muscle ◽

Metabolic Disorders ◽

Muscle Protein ◽

Protein Profiling ◽

Muscle Mitochondria ◽

Mitochondrial Proteome ◽

Complex Disorders

Introduction: Mitochondria are essential in energy metabolism and cellular survival, and there is growing evidence that insulin resistance in chronic metabolic disorders, such as obesity, type 2 diabetes (T2D), and aging, is linked to mitochondrial dysfunction in skeletal muscle. Protein profiling by proteomics is a powerful tool to investigate mechanisms underlying complex disorders. However, despite significant advances in proteomics within the past two decades, the technologies have not yet been fully exploited in the field of skeletal muscle proteome. Area covered: Here, we review the currently available studies characterizing the mitochondrial proteome in human skeletal muscle in insulin-resistant conditions, such as obesity, T2D, and aging, as well as exercise-mediated changes in the mitochondrial proteome. Furthermore, we outline technical challenges and limitations and methodological aspects that should be considered when planning future large-scale proteomics studies of mitochondria from human skeletal muscle. Authors’ view: At present, most proteomic studies of skeletal muscle or isolated muscle mitochondria have demonstrated a reduced abundance of proteins in several mitochondrial biological processes in obesity, T2D, and aging, whereas the beneficial effects of exercise involve an increased content of muscle proteins involved in mitochondrial metabolism. Powerful mass-spectrometry-based proteomics now provides unprecedented opportunities to perform in-depth proteomics of muscle mitochondria, which in the near future is expected to increase our understanding of the complex molecular mechanisms underlying the link between mitochondrial dysfunction and insulin resistance in chronic metabolic disorders.

Download Full-text

1α,25-dihydroxyvitamin D3 mitigates cancer cell mediated mitochondrial dysfunction in human skeletal muscle cells

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2018.01.092 ◽

2018 ◽

Vol 496 (2) ◽

pp. 746-752 ◽

Cited By ~ 7

Author(s):

Zachary C. Ryan ◽

Theodore A. Craig ◽

Xuewei Wang ◽

Philippe Delmotte ◽

Jeffrey L. Salisbury ◽

...

Keyword(s):

Skeletal Muscle ◽

Mitochondrial Dysfunction ◽

Cancer Cell ◽

Human Skeletal Muscle ◽

Muscle Cells ◽

Skeletal Muscle Cells ◽

Dihydroxyvitamin D3 ◽

Human Skeletal Muscle Cells

Download Full-text

Effects of 7 wk of endurance training on human skeletal muscle metabolism during submaximal exercise

Journal of Applied Physiology ◽

10.1152/japplphysiol.00517.2004 ◽

2004 ◽

Vol 97 (6) ◽

pp. 2148-2153 ◽

Cited By ~ 30

Author(s):

Paul J. LeBlanc ◽

Krista R. Howarth ◽

Martin J. Gibala ◽

George J. F. Heigenhauser

Keyword(s):

Skeletal Muscle ◽

Endurance Training ◽

Glycogen Phosphorylase ◽

Human Skeletal Muscle ◽

Vastus Lateralis ◽

Muscle Metabolism ◽

Allosteric Modulators ◽

Before And After ◽

First Time ◽

Muscle Biopsies

This is the first study to examine the effects of endurance training on the activation state of glycogen phosphorylase (Phos) and pyruvate dehydrogenase (PDH) in human skeletal muscle during exercise. We hypothesized that 7 wk of endurance training (Tr) would result in a posttransformationally regulated decrease in flux through Phos and an attenuated activation of PDH during exercise due to alterations in key allosteric modulators of these important enzymes. Eight healthy men (22 ± 1 yr) cycled to exhaustion at the same absolute workload (206 ± 5 W; ∼80% of initial maximal oxygen uptake) before and after Tr. Muscle biopsies (vastus lateralis) were obtained at rest and after 5 and 15 min of exercise. Fifteen minutes of exercise post-Tr resulted in an attenuated activation of PDH (pre-Tr: 3.75 ± 0.48 vs. post-Tr: 2.65 ± 0.38 mmol·min−1·kg wet wt−1), possibly due in part to lower pyruvate content (pre-Tr: 0.94 ± 0.14 vs. post-Tr: 0.46 ± 0.03 mmol/kg dry wt). The decreased pyruvate availability during exercise post-Tr may be due to a decreased muscle glycogenolytic rate (pre-Tr: 13.22 ± 1.01 vs. post-Tr: 7.36 ± 1.26 mmol·min−1·kg dry wt−1). Decreased glycogenolysis was likely mediated, in part, by posttransformational regulation of Phos, as evidenced by smaller net increases in calculated muscle free ADP (pre-Tr: 111 ± 16 vs. post-Tr: 84 ± 10 μmol/kg dry wt) and Pi (pre-Tr: 57.1 ± 7.9 vs. post-Tr: 28.6 ± 5.6 mmol/kg dry wt). We have demonstrated for the first time that several signals act to coordinately regulate Phos and PDH, and thus carbohydrate metabolism, in human skeletal muscle after 7 wk of endurance training.

Download Full-text

Effect of N-acetylcysteine infusion on exercise-induced modulation of insulin sensitivity and signaling pathways in human skeletal muscle

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00605.2014 ◽

2015 ◽

Vol 309 (4) ◽

pp. E388-E397 ◽

Cited By ~ 25

Author(s):

Adam J. Trewin ◽

Leonidas S. Lundell ◽

Ben D. Perry ◽

Kim Vikhe Patil ◽

Alexander V. Chibalin ◽

...

Keyword(s):

Skeletal Muscle ◽

Insulin Sensitivity ◽

Repeated Measures ◽

Insulin Action ◽

Human Skeletal Muscle ◽

Protein Signaling ◽

Insulin Stimulation ◽

Double Blind ◽

Exercise Induced ◽

Muscle Biopsies

—Reactive oxygen species (ROS) produced in skeletal muscle may play a role in potentiating the beneficial responses to exercise; however, the effects of exercise-induced ROS on insulin action and protein signaling in humans has not been fully elucidated. Seven healthy, recreationally active participants volunteered for this double-blind, randomized, repeated-measures crossover study. Exercise was undertaken with infusion of saline (CON) or the antioxidant N-acetylcysteine (NAC) to attenuate ROS. Participants performed two 1-h cycling exercise sessions 7–14 days apart, 55 min at 65% V̇o2peak plus 5 min at 85%V̇o2peak, followed 3 h later by a 2-h hyperinsulinemic euglycemic clamp (40 mIU·min−1·m2) to determine insulin sensitivity. Four muscle biopsies were taken on each trial day, at baseline before NAC infusion (BASE), after exercise (EX), after 3-h recovery (REC), and post-insulin clamp (PI). Exercise, ROS, and insulin action on protein phosphorylation were evaluated with immunoblotting. NAC tended to decrease postexercise markers of the ROS/protein carbonylation ratio by −13.5% ( P = 0.08) and increase the GSH/GSSG ratio twofold vs. CON ( P < 0.05). Insulin sensitivity was reduced (−5.9%, P < 0.05) by NAC compared with CON without decreased phosphorylation of Akt or AS160. Whereas p-mTOR was not significantly decreased by NAC after EX or REC, phosphorylation of the downstream protein synthesis target kinase p70S6K was blunted by 48% at PI with NAC compared with CON ( P < 0.05). We conclude that NAC infusion attenuated muscle ROS and postexercise insulin sensitivity independent of Akt signaling. ROS also played a role in normal p70S6K phosphorylation in response to insulin stimulation in human skeletal muscle.

Download Full-text

Increments in skeletal muscle GLUT-1 and GLUT-4 after endurance training in humans

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1996.270.3.e456 ◽

1996 ◽

Vol 270 (3) ◽

pp. E456-E462 ◽

Cited By ~ 17

Author(s):

S. M. Phillips ◽

X. X. Han ◽

H. J. Green ◽

A. Bonen

Keyword(s):

Skeletal Muscle ◽

Time Course ◽

Human Skeletal Muscle ◽

Prolonged Exercise ◽

Mitochondrial Potential ◽

Glut 1 ◽

Glut 4 ◽

Induced Changes ◽

Muscle Biopsies ◽

Early Training

We investigated the time course of training-induced changes in the expression of GLUT-1 and GLUT-4 in human skeletal muscle. Seven healthy males trained for 2 h/day (approximately 60% pretraining VO2peak) for 31 days (31D). Muscle biopsies were obtained before training (PRE) and after 5 (5D) and 31 days (31D) of training. Training resulted in progressive increases in muscle GLUT-4 with increasing training duration (PRE<5D<31D; P<0.01). Muscle GLUT-1 content was also increased (P<0.05) after training; however, the increase was not observed until 31D (131%). Increases in muscle hexokinase (HK) activity were complete by 5D (P<0.01). Muscle malate dehydrogenase activity was not elevated after 5D of training but was increased (+35%; P<0.01) at 31D. Results from this study show that increases in both GLUT-4 and HK represent early training-induced adaptations to prolonged exercise training. As training progresses, further increases in GLUT-4, but not HK, occur in conjunction with an increase in muscle mitochondrial potential and GLUT-1.

Download Full-text

Contraction-mediated inactivation of glycogen synthase is accompanied by inactivation of glycogen synthase phosphatase in human skeletal muscle

Biochemical Journal ◽

10.1042/bj2590901 ◽

1989 ◽

Vol 259 (3) ◽

pp. 901-904 ◽

Cited By ~ 10

Author(s):

Y Kida ◽

A Katz ◽

A D Lee ◽

D M Mott

Keyword(s):

Skeletal Muscle ◽

Isometric Contraction ◽

Human Skeletal Muscle ◽

Glycogen Synthase ◽

Active Form ◽

Human Muscle ◽

Maximal Voluntary Force ◽

Before And After ◽

Muscle Biopsies

Activities of glycogen synthase (GS) and GS phosphatase were determined on human muscle biopsies before and after isometric contraction at 2/3 maximal voluntary force. Total GS activity did not change during contraction (4.92 +/- 0.70 at rest versus 5.00 +/- 0.42 mmol/min per kg dry wt.; mean +/- S.E.M.), whereas both the active form of GS and the ratio of active form to total GS decreased by approximately 35% (P less than 0.01). GS phosphatase was inactivated in all subjects by an average of 39%, from 5.95 +/- 1.30 to 3.63 +/- 0.97 mmol/min per kg dry wt. (P less than 0.01). It is suggested that at least part of the contraction-induced inactivation of GS is due to an inactivation of GS phosphatase.

Download Full-text

Insulin induces translocation of GLUT-4 glucose transporters in human skeletal muscle

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1995.268.4.e613 ◽

1995 ◽

Vol 268 (4) ◽

pp. E613-E622 ◽

Cited By ~ 22

Author(s):

A. Guma ◽

J. R. Zierath ◽

H. Wallberg-Henriksson ◽

A. Klip

Keyword(s):

Skeletal Muscle ◽

Plasma Membrane ◽

Human Skeletal Muscle ◽

Molecular Mechanisms ◽

Glucose Transporter ◽

Vastus Lateralis ◽

Glucose Transporters ◽

Membrane Markers ◽

Glut 4 ◽

Muscle Biopsies

Understanding the molecular mechanisms involved in the regulation of glucose transport into human muscle is necessary to unravel possible defects in glucose uptake associated with insulin resistance in humans. Here we report a strategy to subfractionate human skeletal muscle biopsies (0.5 g) removed from vastus lateralis during a euglycemic insulinemic clamp procedure. A sucrose gradient separated total membranes into five fractions. Fraction 25 (25% sucrose) contained the plasma membrane markers alpha 1- and alpha 2-subunits of the Na(+)-K(+)-adenosinetriphosphatase and the GLUT-5 hexose transporter, recently immunolocalized to the cell surface of human skeletal muscle. The dihydropyridine receptor, a transverse tubule marker, was present exclusively in this fraction. The GLUT-4 glucose transporter was more concentrated in fraction 27.5 (27.5% sucrose) and largely diminished in plasma membrane markers. Open skeletal muscle biopsies were removed before and 30 min after clamping insulin to 550 pM. This increased GLUT-4 protein by 1.61-fold in fraction 25 and lowered it by 50% in fraction 27.5. Thus physiological concentrations of insulin induce translocation of glucose transporters from an internal membrane pool to surface membranes in human skeletal muscle.

Download Full-text