Endurance exercise activates matrix metalloproteinases in human skeletal muscle

2009 ◽  
Vol 106 (3) ◽  
pp. 804-812 ◽  
Author(s):  
Eric Rullman ◽  
Jessica Norrbom ◽  
Anna Strömberg ◽  
Dick Wågsäter ◽  
Helene Rundqvist ◽  
...  

In the present study, the effect of exercise training on the expression and activity of matrix metalloproteinases (MMPs) in the human skeletal muscle was investigated. Ten subjects exercised one leg for 45 min with restricted blood flow and then exercised the other leg at the same absolute workload with unrestricted blood flow. The exercises were conducted four times per week for 5 wk. Biopsies were taken from the vastus lateralis muscles of both legs at rest before the training period, after 10 days and 5 wk of training, and 2 h after the first exercise bout for analysis of MMP and tissue inhibitor of metalloproteinase-1 (TIMP-1) mRNA, enzyme activity, and protein expression. Levels of MMP-2, MMP-14, and TIMP-1 mRNA in muscle tissue increased after 10 days of training regardless of blood flow condition. MMP-2 mRNA level in laser-dissected myofibers and MMP-2 activity in whole muscle increased with training. The level of MMP-9 mRNA and activity increased after the first bout of exercise. Although MMP-9 mRNA levels appeared to be very low, the activity of MMP-9 after a single bout of exercise was similar to that of MMP-2 after 10 days of exercise. MMP-2 and MMP-9 protein was both present throughout the extracellular matrix of the muscle, both around fibers and capillaries, but MMP-2 was also present within the skeletal muscle fibers. These results show that MMPs are activated in skeletal muscle in nonpathological conditions such as voluntary exercise. The expression and time pattern indicate differences between the MMPs in regards of production sites as well as in the regulating mechanism.

2007 ◽  
Vol 103 (3) ◽  
pp. 1012-1020 ◽  
Author(s):  
T. Gustafsson ◽  
H. Rundqvist ◽  
J. Norrbom ◽  
E. Rullman ◽  
E. Jansson ◽  
...  

Eleven subjects performed one-legged exercise four times per week for 5 wk. The subjects exercised one leg for 45 min with restricted blood flow (R leg), followed by exercise with the other leg at the same absolute workload with unrestricted blood flow (UR leg). mRNA and protein expression were measured in biopsies from the vastus lateralis muscle obtained at rest before the training period, after 10 days, and after 5 wk of training, as well as 120 min after the first and last exercise bouts. Basal Ang-2 and Tie-1 mRNA levels increased in both legs with training. The Ang-2-to-Ang-1 ratio increased to a greater extent in the R leg. The changes in Ang-2 mRNA were followed by similar changes at the protein level. In the R leg, VEGF-A mRNA expression responded transiently after acute exercise both before and after the 5-wk training program. Over the course of the exercise program, there was a concurrent increase in basal VEGF-A protein and VEGFR-2 mRNA in the R leg. Ki-67 mRNA showed a greater increase in the R leg and the protein was localized to the endothelial cells. In summary, the increased translation of VEGF-A is suggested to be caused by the short mRNA burst induced by each exercise bout. The concurrent increase in the Ang-2-to-Ang-1 ratio and the VEGF-expression combined with the higher level of Ki-67 mRNA in the R leg indicate that changes in these systems are of importance also in nonpathological angiogenic condition such as voluntary exercise in humans. It further establish that hypoxia/ischemia-related metabolic perturbation is likely to be involved as stimuli in this process in human skeletal muscle.


1978 ◽  
Vol 45 (6) ◽  
pp. 852-857 ◽  
Author(s):  
P. D. Gollnick ◽  
J. Karlsson ◽  
K. Piehl ◽  
B. Saltin

Experiments were conducted to examine the conversions of phosphorylase b to phosphorylase a in human skeletal muscle during bicycle exercise or isometric contractions. Muscle biopsies were obtained from the vastus lateralis with the needle technique at rest and either during or immediately after activity and frozen in liquid nitrogen within 2--4 s. Total phosphorylase and phosphorylase a activities were differentiated by measurement in the presence and absence of AMP, respectively. At rest 8.5% of the total phosphorylase activity existed in the a form. Little or no change in the percent of phosphorylase in the a form occurred during voluntary dynamic or static muscular activity that produced muscle lactate concentrations in excess of 18 mmol.kg-1 wet muscle. Electrical stimulation of the vastus lateralis muscle also failed to produce an increase in the percentage of phosphorylase a. These data suggest that during exercise the conversion of phosphorylase to the a form is of minor importance. An increased activity of phosphorylase b due to changes in muscle concentrations of ATP, AMP, and inorganic phosphate may regulate glycogenolysis during voluntary exercise in man.


1993 ◽  
Vol 75 (6) ◽  
pp. 2471-2477 ◽  
Author(s):  
F. Haddad ◽  
R. E. Herrick ◽  
G. R. Adams ◽  
K. M. Baldwin

This study ascertained the effects of 9 days of zero gravity on the relative (percentage of total) and calculated absolute (mg/muscle) content of isomyosin expressed in both antigravity and locomotor skeletal muscle of ground control (CON) and flight-exposed (FL) rats. Results showed that although there were no differences in body weight between FL and CON animals, a significant reduction in muscle mass occurred in the vastus intermedius (VI) (P < 0.05) but not in the vastus lateralis (VL) or the tibialis anterior. Both total muscle protein and myofibril protein content were not different between the muscle regions examined in the FL and CON groups. In the VI, there were trends for reductions in the relative content of type I and IIa myosin heavy chains (MHCs) that were offset by increases in the relative content of both type IIb and possibly type IIx MHC protein (P > 0.05). mRNA levels were consistent with this pattern (P < 0.05). The same pattern held true for the red region of the VL as examined at both the protein and mRNA level (P < 0.05). When the atrophy process was examined, there were net reductions in the absolute content of both type I and IIa MHCs that were offset by calculated increases in type IIb MHC in both VI and red VL. Collectively, these findings suggest that there are both absolute and relative changes occurring in MHC expression in the "red" regions of antigravity skeletal muscle during exposure to zero gravity that could affect muscle function.


2016 ◽  
Vol 310 (3) ◽  
pp. R297-R304 ◽  
Author(s):  
Anna Strömberg ◽  
Karl Olsson ◽  
Jacomijn P. Dijksterhuis ◽  
Eric Rullman ◽  
Gunnar Schulte ◽  
...  

Monocytes/macrophages (MOs/MΦs) are suggested to be crucial for skeletal muscle repair and remodeling. This has been attributed to their proangiogenic potential, secretion of growth factors, and clearance of tissue debris. Skeletal muscle injury increases the number of MΦs in the tissue, and their importance for muscle regeneration has been supported by studies demonstrating that depletion of MOs/MΦs greatly impairs repair after muscle injury. Whether noninjurious exercise leads to induced expression of chemoattractants for MOs/MΦs is poorly investigated. To this end, we analyzed the expression of CX3CL1 (fractalkine), CCL2 (MCP-1), and CCL22 (MDC) in human skeletal muscle after a bout of exercise, all of which are established MO/MΦ chemotactic factors that are expressed by human myoblasts. Muscle biopsies from the musculus vastus lateralis were obtained up to 24 h after 1 h of cycle exercise in healthy individuals and in age-matched nonexercised controls. CX3CL1 increased at both the mRNA and protein level in human skeletal muscle after one bout of exercise. It was not possible to distinguish changes in CCL2 or CCL22 mRNA levels between biopsy vs. exercise effects, and the expression of CCL22 was very low. CX3CL1 mainly localized to the skeletal muscle endothelium, and it increased in human umbilical vein endothelial cells stimulated with tissue fluid from exercised muscle. CX3CL1 increased the expression of proinflammatory and proangiogenic factors in THP-1 monocytes (a human acute monocytic leukemia cell line) and in human primary myoblasts and myotubes. Altogether, this suggests that CX3CL1 participates in cross-talk mechanisms between endothelium and other muscle tissue cells and may promote a shift in the microenvironment toward a more regenerative milieu.


2000 ◽  
Vol 279 (2) ◽  
pp. H772-H778 ◽  
Author(s):  
R. S. Richardson ◽  
H. Wagner ◽  
S. R. D. Mudaliar ◽  
E. Saucedo ◽  
R. Henry ◽  
...  

Angiogenesis is a component of the multifactoral adaptation to exercise training, and vascular endothelial growth factor (VEGF) is involved in extracellular matrix changes and endothelial cell proliferation. However, there is limited evidence supporting the role of VEGF in the exercise training response. Thus we studied mRNA levels of VEGF, using quantitative Northern analysis, in untrained and trained human skeletal muscle at rest and after a single bout of exercise. Single leg knee-extension provided the acute exercise stimulus and the training modality. Four biopsies were collected from the vastus lateralis muscle at rest in the untrained and trained conditions before and after exercise. Training resulted in a 35% increase in muscle oxygen consumption and an 18% increase in number of capillaries per muscle fiber. At rest, VEGF/18S mRNA levels were similar before (0.38 ± 0.04) and after (1.2 ± 0.4) training. When muscle was untrained, acute exercise greatly elevated VEGF/18S mRNA levels (16.9 ± 6.7). The VEGF/18S mRNA response to acute exercise in the trained state was markedly attenuated (5.4 ± 1.3). These data support the concept that VEGF is involved in exercise-induced skeletal muscle angiogenesis and appears to be subject to a negative feedback mechanism as exercise adaptations occur.


2009 ◽  
Vol 296 (4) ◽  
pp. R1140-R1148 ◽  
Author(s):  
Stefan P. Mortensen ◽  
José González-Alonso ◽  
Laurids T. Bune ◽  
Bengt Saltin ◽  
Henriette Pilegaard ◽  
...  

Plasma ATP is thought to contribute to the local regulation of skeletal muscle blood flow. Intravascular ATP infusion can induce profound limb muscle vasodilatation, but the purinergic receptors and downstream signals involved in this response remain unclear. This study investigated: 1) the role of nitric oxide (NO), prostaglandins, and adenosine as mediators of ATP-induced limb vasodilation and 2) the expression and distribution of purinergic P2 receptors in human skeletal muscle. Systemic and leg hemodynamics were measured before and during 5–7 min of femoral intra-arterial infusion of ATP [0.45–2.45 μmol/min] in 19 healthy male subjects with and without coinfusion of NG-monomethyl-l-arginine (l-NMMA; NO formation inhibitor; 12.3 ± 0.3 (SE) mg/min), indomethacin (INDO; prostaglandin formation blocker; 613 ± 12 μg/min), and/or theophylline (adenosine receptor blocker; 400 ± 26 mg). During control conditions, ATP infusion increased leg blood flow (LBF) from baseline conditions by 1.82 ± 0.14 l/min. When ATP was coinfused with either l-NMMA, INDO, or l-NMMA + INDO combined, the increase in LBF was reduced by 14 ± 6, 15 ± 9, and 39 ± 8%, respectively (all P < 0.05), and was associated with a parallel lowering in leg vascular conductance and cardiac output and a compensatory increase in leg O2 extraction. Infusion of theophylline did not alter the ATP-induced leg hyperemia or systemic variables. Real-time PCR analysis of the mRNA content from the vastus lateralis muscle of eight subjects showed the highest expression of P2Y2 receptors of the 10 investigated P2 receptor subtypes. Immunohistochemistry showed that P2Y2 receptors were located in the endothelium of microvessels and smooth muscle cells, whereas P2X1 receptors were located in the endothelium and the sacrolemma. Collectively, these results indicate that NO and prostaglandins, but not adenosine, play a role in ATP-induced vasodilation in human skeletal muscle. The expression and localization of the nucleotide selective P2Y2 and P2X1 receptors suggest that these receptors may mediate ATP-induced vasodilation in skeletal muscle.


2009 ◽  
Vol 106 (4) ◽  
pp. 1419-1424 ◽  
Author(s):  
Maarit Lehti ◽  
Riikka Kivelä ◽  
Paavo Komi ◽  
Jyrki Komulainen ◽  
Heikki Kainulainen ◽  
...  

Eccentric exercise induced by electrostimulation increases mRNA expression of titin-complex proteins in rodent skeletal muscle. In this study, mRNA expression of titin, muscle LIM protein (MLP), cardiac ankyrin repeat protein (CARP), ankyrin repeat domain protein 2 (Ankrd2), diabetes-related ankyrin repeat protein (DARP), and calcium-activated proteinases, calpains, were investigated in human skeletal muscle after fatiguing jumping exercise. Fatiguing jumping exercise did not change mRNA expression of titin, DARP, calpain 1, or calpain 3. MLP, Ankrd2 and calpain 2 mRNA levels were increased 2 days postexercise. CARP mRNA level was already elevated 30 min and remained elevated 2 days postexercise. Increased mRNA expression of MLP, CARP, and Ankrd2, observed for the first time in human skeletal muscle, may be part of the signaling activated by physical exercise. The rapid increase in the level of CARP mRNA nominates CARP as one of the first genes to respond to exercise. The increase in the mRNA level of calpain 2 suggests its involvement in myofiber remodeling after strenuous jumping exercise.


2005 ◽  
Vol 289 (1) ◽  
pp. R84-R91 ◽  
Author(s):  
Nikolai Nordsborg ◽  
Martin Thomassen ◽  
Carsten Lundby ◽  
Henriette Pilegaard ◽  
Jens Bangsbo

The present study tested the hypothesis that exercise with a large compared with a small active muscle mass results in a higher contraction-induced increase in Na+-K+-ATPase mRNA expression due to greater hormonal responses. Furthermore, the relative abundance of Na+-K+-ATPase subunit α1, α2, α3, α4, β1, β2, and β3 mRNA in human skeletal muscle was investigated. On two occasions, eight subjects performed one-legged knee extension exercise (L) or combined one-legged knee extension and bilateral arm cranking (AL) for 5.00, 4.25, 3.50, 2.75, and 2.00 min separated by 3 min of rest. Leg exercise power output was the same in AL and L, but heart rate at the end of each exercise interval was higher in AL compared with L. One minute after exercise, arm venous blood lactate was higher in AL than in L. A higher level of blood epinephrine and norepinephrine was evident 3 min after exercise in AL compared with L. Nevertheless, none of the exercise-induced increases in α1, α2, β1, and β3 mRNA expression levels were higher in AL compared with L. The most abundant Na+-K+-ATPase subunit at the mRNA level was β1, which was expressed 3.4 times than α2. Expression of α1, β2, and β3 was less than 5% of the α2 expression, and no reliable detection of α3 and α4 was possible. In conclusion, activation of additional muscle mass does not result in a higher exercise-induced increase in Na+-K+-ATPase subunit-specific mRNA.


2003 ◽  
Vol 95 (3) ◽  
pp. 1038-1044 ◽  
Author(s):  
Niklas Psilander ◽  
Rasmus Damsgaard ◽  
Henriette Pilegaard

Increasing evidence suggests that the myogenic regulatory factors (MRFs) and IGF-I have important roles in the hypertrophy response observed after mechanical loading. We, therefore, hypothesized that a bout of heavy-resistance training would affect the MRF and IGF-I mRNA levels in human skeletal muscle. Six male subjects completed four sets of 6-12 repetitions on a leg press and knee extensor machine separated by 3 min. Myogenin, MRF4, MyoD, IGF-IEabc (isoforms a, b, and c) and IGF-IEbc (isoform b and c) mRNA levels were determined in the vastus lateralis muscle by RT-PCR before exercise, immediately after, and 1, 2, 6, 24, and 48 h postexercise. Myogenin, MyoD, and MRF4 mRNA levels were elevated ( P < 0.005) by 100-400% 0-24 h postexercise. IGF-IEabc mRNA content decreased ( P < 0.005) by ∼44% after 1 and 6 h of recovery. The IGF-IEbc mRNA level was unaffected. The present study shows that myogenin, MyoD, and MRF4 mRNA levels are transiently elevated in human skeletal muscle after a single bout of heavy-resistance training, supporting the idea that the MRFs may be involved in regulating hypertrophy and/or fiber-type transitions. The results also suggest that IGF-IEa expression may be downregulated at the mRNA level during the initial part of recovery from resistance exercise.


2015 ◽  
Vol 309 (8) ◽  
pp. L857-L871 ◽  
Author(s):  
Shelly R. H. Pecorella ◽  
Jennifer V. F. Potter ◽  
Anne D. Cherry ◽  
Dionne F. Peacher ◽  
Karen E. Welty-Wolf ◽  
...  

The heme oxygenase-1 (HO-1)/carbon monoxide (CO) system induces mitochondrial biogenesis, but its biological impact in human skeletal muscle is uncertain. The enzyme system generates CO, which stimulates mitochondrial proliferation in normal muscle. Here we examined whether CO breathing can be used to produce a coordinated metabolic and vascular response in human skeletal muscle. In 19 healthy subjects, we performed vastus lateralis muscle biopsies and tested one-legged maximal O2 uptake (V̇o2max) before and after breathing air or CO (200 ppm) for 1 h daily for 5 days. In response to CO, there was robust HO-1 induction along with increased mRNA levels for nuclear-encoded mitochondrial transcription factor A (Tfam), cytochrome c, cytochrome oxidase subunit IV (COX IV), and mitochondrial-encoded COX I and NADH dehydrogenase subunit 1 (NDI). CO breathing did not increase V̇o2max (1.96 ± 0.51 pre-CO, 1.87 ± 0.50 post-CO l/min; P = not significant) but did increase muscle citrate synthase, mitochondrial density (139.0 ± 34.9 pre-CO, 219.0 ± 36.2 post-CO; no. of mitochondrial profiles/field), myoglobin content and glucose transporter (GLUT4) protein level and led to GLUT4 localization to the myocyte membrane, all consistent with expansion of the tissue O2 transport system. These responses were attended by increased cluster of differentiation 31 (CD31)-positive muscle capillaries (1.78 ± 0.16 pre-CO, 2.37 ± 0.59 post-CO; capillaries/muscle fiber), implying the enrichment of microvascular O2 reserve. The findings support that induction of the HO-1/CO system by CO not only improves muscle mitochondrial density, but regulates myoglobin content, GLUT4 localization, and capillarity in accordance with current concepts of skeletal muscle plasticity.


Sign in / Sign up

Export Citation Format

Share Document