mRNA levels for α-subunit of prolyl 4-hydroxylase and fibrillar collagens in immobilized rat skeletal muscle

1999 ◽  
Vol 87 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Xiao-Yan Han ◽  
Wei Wang ◽  
Raili Myllylä ◽  
Paula Virtanen ◽  
Jarmo Karpakka ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Tibialis Anterior ◽  
Collagen Synthesis ◽  
Plantar Flexion ◽  
Mrna Level ◽  
Type I ◽  
Mrna Levels ◽  
Rat Skeletal Muscle ◽  
Α Subunit ◽  
Fibrillar Collagens

There is evidence that immobilization causes a decrease in total collagen synthesis in skeletal muscle within a few days. In this study, early immobilization effects on the expression of prolyl 4-hydroxylase (PH) and the main fibrillar collagens at mRNA and protein levels were investigated in rat skeletal muscle. The right hindlimb was immobilized in full plantar flexion for 1, 3, and 7 days. Steady-state mRNAs for α- and β-subunits of PH and type I and III procollagen, PH activity, and collagen content were measured in gastrocnemius and plantaris muscles. Type I and III procollagen mRNAs were also measured in soleus and tibialis anterior muscles. The mRNA level for the PH α-subunit decreased by 49 and 55% ( P < 0.01) in gastrocnemius muscle and by 41 and 39% ( P < 0.05) in plantaris muscle after immobilization for 1 and 3 days, respectively. PH activity was decreased ( P < 0.05–0.01) in both muscles at days 3 and 7. The mRNA levels for type I and III procollagen were decreased by 26–56% ( P < 0.05–0.001) in soleus, tibialis anterior, and plantaris muscles at day 3. The present results thus suggest that pretranslational downregulation plays a key role in fibrillar collagen synthesis in the early phase of immobilization-induced muscle atrophy.

scholarly journals Myosin heavy chain expression in rodent skeletal muscle: effects of exposure to zero gravity

1993 ◽  
Vol 75 (6) ◽  
pp. 2471-2477 ◽  
Author(s):  
F. Haddad ◽  
R. E. Herrick ◽  
G. R. Adams ◽  
K. M. Baldwin
Keyword(s):  
Skeletal Muscle ◽  
Muscle Protein ◽  
Vastus Lateralis ◽  
Mrna Level ◽  
Relative Content ◽  
Type I ◽  
Zero Gravity ◽  
Mrna Levels ◽  
Heavy Chains ◽  
Vastus Intermedius

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.

Skeletal muscle collagen type I and III mRNA, [corrected] prolyl 4-hydroxylase, and collagen in hypobaric trained rats

1996 ◽  
Vol 80 (6) ◽  
pp. 2226-2233 ◽  
Author(s):  
M. Perhonen ◽  
X. Han ◽  
W. Wang ◽  
J. Karpakka ◽  
T. E. Takala
Keyword(s):  
Skeletal Muscle ◽  
Soleus Muscle ◽  
Collagen Type ◽  
Mrna Level ◽  
Collagen Type I ◽  
Synthesis Rate ◽  
Type I ◽  
Mrna Levels ◽  
Edl Muscle ◽  
And Training

Skeletal muscle collagen expression was studied in normobaric sedentary (NS) and training (NT) and hypobaric sedentary (HS) and training (HT) rats after experimental periods of 10, 21, and 56 days. The weights of fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus muscles were increased between the experimental period of 21 and 56 days so that EDL weight was 57 (P < 0.01) and 36% (P < 0.05) higher in 56 days HS (56HS) and 56 days HT (56HT), respectively, than in 56 days NS (56NS). Soleus muscle weight was higher in 56HS (61%; P < 0.01) and in 56HT (27%; P < 0.05) than in 56NT. In EDL muscle, collagen type I mRNA level was lower in 56HT than in 56NS (36%; P < 0.05) and 56NT (44%; P < 0.01). In 56HT, collagen type III mRNA level was 39 (P < 0.01) and 42% (P < 0.05) lower than in 56NS and 56HS, respectively. In soleus muscle, prolyl 4-hydroxylase activity was greater (P < 0.05) in 56NT, 56HS, and 56HT than in 56NS. Total hydroxyproline content in EDL muscle was increased in 56HS and 56HT and in soleus muscle of 56HS. In conclusion, although collagen types I and III mRNA levels in EDL muscle decreased in 56HT, the prolyl 4-hydroxylase data suggest unchanged synthesis of total collagen. Exposure to hypobaric conditions as such, its combination to endurance training, as well as training in normobaric conditions increased prolyl 4-hydroxylation capacity in soleus muscle, which may indicate respective change in collagen synthesis rate.

Effects of denervation and immobilization on collagen synthesis in rat skeletal muscle and tendon

1988 ◽  
Vol 254 (6) ◽  
pp. R897-R902 ◽  
Author(s):  
J. Savolainen ◽  
V. Myllyla ◽  
R. Myllyla ◽  
V. Vihko ◽  
K. Vaananen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Tibialis Anterior ◽  
Collagen Synthesis ◽  
Gastrocnemius Muscle ◽  
Collagen Biosynthesis ◽  
Denervation Atrophy ◽  
Rat Skeletal Muscle ◽  
Cast Immobilization ◽  
Collagen Concentration ◽  
Denervated Muscles

The activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT), both enzymes of collagen biosynthesis, and the concentration of hydroxyproline (HYP) were measured in the gastrocnemius, soleus, and tibialis anterior muscles of rats after sciatic nerve neurectomy combined with cast immobilization of the denervated limb for 1 and 3 wk. PH and GGT were also observed in Achilles and tibialis anterior tendons after cast immobilization without neurectomy. After neurectomy the specific PH activity in the denervated gastrocnemius muscle increased by 215% (P less than 0.001). The specific GGT activity increased by 92-110% (P less than 0.01) in the denervated gastrocnemius, soleus, and tibialis anterior muscles. Elevation of the muscular HYP concentration by 118-170% (P less than 0.001) in the denervated muscles was observed. The PH, GGT, and HYP responses of the denervated muscles immobilized at a lengthened or shortened position during denervation atrophy did not generally differ significantly from those of the unfixed denervated ones. The specific PH and GGT activities of the disused tendons decreased by 62 (P less than 0.01) and 25% (P less than 0.001), respectively, in tendons immobilized in a chronically shortened position. The results suggest that denervation atrophy of skeletal muscle is associated with both an increased level of muscular collagen biosynthesis and with an increased muscular collagen concentration. The PH and GGT responses of the cast-immobilized tendons suggest adaptive changes in collagen biosynthesis of the disused tendon.

Effect of reinnervation on collagen synthesis in rat skeletal muscle

1992 ◽  
Vol 72 (6) ◽  
pp. 2069-2074 ◽  
Author(s):  
P. Virtanen ◽  
U. Tolonen ◽  
J. Savolainen ◽  
T. E. Takala
Keyword(s):  
Skeletal Muscle ◽  
Sciatic Nerve ◽  
Tibialis Anterior ◽  
Collagen Synthesis ◽  
Tibialis Anterior Muscle ◽  
Control Level ◽  
Synthesis Rate ◽  
Collagen Biosynthesis ◽  
Denervation Atrophy ◽  
Rat Skeletal Muscle

The effect of reinnervation on the activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT), both enzymes of collagen biosynthesis, and on the concentration of hydroxyproline (Hyp) was studied in gastrocnemius, soleus, and tibialis anterior muscles of rat 19, 26, 40, and 61 days after crush denervation of the sciatic nerve. The GGT activity was elevated in denervated gastrocnemius and soleus muscles and the PH activity in gastrocnemius. Muscular Hyp concentration was increased in denervated tibialis anterior muscle. Both the PH and GGT activities and the Hyp concentration returned to the control level during the reinnervation period (19–61 days from the start of denervation). It seems that denervation atrophy of skeletal muscle is associated with an increased rate of muscular collagen biosynthesis and that during reinnervation collagen synthesis rate decreases despite accelerated muscular growth. The results thus suggest that innervation is a powerful suppressive regulator of muscular collagen biosynthesis.

Transmembrane prolyl 4-hydroxylase is a fourth prolyl 4-hydroxylase regulating EPO production and erythropoiesis

Blood ◽  
2012 ◽  
Vol 120 (16) ◽  
pp. 3336-3344 ◽  
Author(s):  
Anu Laitala ◽  
Ellinoora Aro ◽  
Gail Walkinshaw ◽  
Joni M. Mäki ◽  
Maarit Rossi ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Mrna Level ◽  
Hypoxia Inducible Factor ◽  
Mrna Levels ◽  
Wild Type ◽  
Α Subunit ◽  
Hepcidin Expression ◽  
In The Wild ◽  
Hepcidin Mrna

AbstractAn endoplasmic reticulum transmembrane prolyl 4-hydroxylase (P4H-TM) is able to hydroxylate the α subunit of the hypoxia-inducible factor (HIF) in vitro and in cultured cells, but nothing is known about its roles in mammalian erythropoiesis. We studied such roles here by administering a HIF-P4H inhibitor, FG-4497, to P4h-tm−/− mice. This caused larger increases in serum Epo concentration and kidney but not liver Hif-1α and Hif-2α protein and Epo mRNA levels than in wild-type mice, while the liver Hepcidin mRNA level was lower in the P4h-tm−/− mice than in the wild-type. Similar, but not identical, differences were also seen between FG-4497–treated Hif-p4h-2 hypomorphic (Hif-p4h-2gt/gt) and Hif-p4h-3−/− mice versus wild-type mice. FG-4497 administration increased hemoglobin and hematocrit values similarly in the P4h-tm−/− and wild-type mice, but caused higher increases in both values in the Hif-p4h-2gt/gt mice and in hematocrit value in the Hif-p4h-3−/− mice than in the wild-type. Hif-p4h-2gt/gt/P4h-tm−/− double gene-modified mice nevertheless had increased hemoglobin and hematocrit values without any FG-4497 administration, although no such abnormalities were seen in the Hif-p4h-2gt/gt or P4h-tm−/− mice. Our data thus indicate that P4H-TM plays a role in the regulation of EPO production, hepcidin expression, and erythropoiesis.

Properties of 5′-deiodinase of 3,3′,5′-triiodothyronine in rat skeletal muscle

1989 ◽  
Vol 120 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Fujiko Tsukahara ◽  
Teruko Nomoto ◽  
Michiko Maeda
Keyword(s):  
Skeletal Muscle ◽  
Drinking Water ◽  
Incubation Medium ◽  
Marked Reduction ◽  
Daily Administration ◽  
Type I ◽  
Rat Skeletal Muscle ◽  
Thyroid Status ◽  
Altered Thyroid

Abstract. To characterize rT3 5′-deiodinase (5′D) in rat skeletal muscle, the effects of altered thyroid status and PTU on rT3 5′D were studied. rT3 5′D activity was measured by incubating homogenates of rat skeletal muscle with [125]rT3, iodine labelled in the outer ring, in the presence of 20 mmol/l DL-dithiothreitol. This activity was observed to increase significantly 24 h after a single sc injection of T3 (75 μg/kg). The increase following the daily administration of this drug (15 or 75 μg/kg) for 3 and 14 days was dependent on the dose and number of previous days of injection. A significant decrease in activity was observed 2 weeks after thyroidectomy. The addition of 0.1 mmol/l 6-n-propyl-2-thiouracil (PTU) to the incubation medium in vitro caused a marked reduction in the activity in homogenates of skeletal muscle from hypothyroid, euthyroid and hyperthyroid rats. PTU, present at 0.05% in the drinking water for 2 weeks virtually abolished it. The properties of rT3 5′D in rat skeletal muscle thus appear to be essentially the same as those of type I enzyme with respect to response toward altered thyroid status and PTU.

scholarly journals Regulation of angiopoietin-like protein 4/fasting-induced adipose factor (Angptl4/FIAF) expression in mouse white adipose tissue and 3T3-L1 adipocytes

2008 ◽  
Vol 100 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Sarah Dutton ◽  
Paul Trayhurn
Keyword(s):  
Skeletal Muscle ◽  
Cell Culture ◽  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Culture Medium ◽  
Mrna Level ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Before And After ◽  
Stimulation Of

Angiopoietin-like protein 4 (Angptl4)/FIAF (fasting-induced adipose factor) was first identified as a target for PPAR and to be strongly induced in white adipose tissue (WAT) by fasting. Here we have examined the regulation of the expression and release of this adipokine in mouse WAT and in 3T3-L1 adipocytes. Angptl4/FIAF expression was measured by RT-PCR and real-time PCR; plasma Angptl4/FIAF and release of the protein in cell culture was determined by western blotting. The Angptl4/FIAF gene was expressed in each of the major WAT depots of mice, the mRNA level in WAT being similar to the liver and much higher (>50-fold) than skeletal muscle. Fasting mice (18 h) resulted in a substantial increase in Angptl4/FIAF mRNA in liver and muscle (9·5- and 21-fold, respectively); however, there was no effect of fasting on Angptl4/FIAF mRNA in WAT and the plasma level of Angptl4/FIAF was unchanged. The Angptl4/FIAF gene was expressed in 3T3-L1 adipocytes before and after differentiation, the level increasing post-differentiation; Angptl4/FIAF was released into the culture medium. Insulin, leptin, dexamethasone, noradrenaline, TNFα and several IL (IL-1β, IL-6, IL-10, IL-18) had little effect on Angptl4/FIAF mRNA levels in 3T3-L1 adipocytes. However, a major stimulation of Angptl4/FIAF expression was observed with rosiglitazone and the inflammatory prostaglandins PGD2 and PGJ2. Angptl4/FIAF does not act as an adipose tissue signal of nutritional status, but is markedly induced by fasting in liver and skeletal muscle.

Exercise increases the plasma membrane content of the Na+ -K+ pump and its mRNA in rat skeletal muscles

1996 ◽  
Vol 80 (2) ◽  
pp. 699-705 ◽  
Author(s):  
T. Tsakiridis ◽  
P. P. Wong ◽  
Z. Liu ◽  
C. D. Rodgers ◽  
M. Vranic ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Skeletal Muscles ◽  
Plasma Membranes ◽  
Acute Exercise ◽  
Treadmill Running ◽  
Type I ◽  
Mrna Levels ◽  
Subunit Mrna ◽  
White Type

Muscle fibers adapt to ionic challenges of exercise by increasing the plasma membrane Na+-K+ pump activity. Chronic exercise training has been shown to increase the total amount of Na+-K+ pumps present in skeletal muscle. However, the mechanism of adaptation of the Na+-K+ pump to an acute bout of exercise has not been determined, and it is not known whether it involves alterations in the content of plasma membrane pump subunits. Here we examine the effect of 1 h of treadmill running (20 m/min, 10% grade) on the subcellular distribution and expression of Na+-K+ pump subunits in rat skeletal muscles. Red type I and IIa (red-I/IIa) and white type IIa and IIb (white-IIa/IIb) hindlimb muscles from resting and exercised female Sprague-Dawley rats were removed for subcellular fractionation. By homogenization and gradient centrifugation, crude membranes and purified plasma membranes were isolated and subjected to gel electrophoresis and immunoblotting by using pump subunit-specific antibodies. Furthermore, mRNA was isolated from specific red type I (red-I) and white type IIb (white-IIb) muscles and subjected to Northern blotting by using subunit-specific probes. In both red-I/IIa and white-IIa/IIb muscles, exercise significantly raised the plasma membrane content of the alpha1-subunit of the pump by 64 +/- 24 and 55 +/- 22%, respectively (P < 0.05), and elevated the alpha2-polypeptide by 43 +/- 22 and 94 +/- 39%, respectively (P < 0.05). No significant effect of exercise could be detected on the amount of these subunits in an internal membrane fraction or in total membranes. In addition, exercise significantly increased the alpha1-subunit mRNA in red-I muscle (by 50 +/- 7%; P < 0.05) and the beta2-subunit mRNA in white-IIb muscles (by 64 +/- 19%; P < 0.01), but the alpha2- and beta1-mRNA levels were unaffected in this time period. We conclude that increased presence of alpha1- and alpha2-polypeptides at the plasma membrane and subsequent elevation of the alpha1- and beta2-subunit mRNAs may be mechanisms by which acute exercise regulates the Na+-K+ pump of skeletal muscle.

Sign in / Sign up

Export Citation Format

Share Document