Effects of exercise training on atrophy gene expression in skeletal muscle of mice with chronic allergic lung inflammation

We evaluated the effects of chronic allergic airway inflammation and of treadmill training (12 weeks) of low and moderate intensity on muscle fiber cross-sectional area and mRNA levels of atrogin-1 and MuRF1 in the mouse tibialis anterior muscle. Six 4-month-old male BALB/c mice (28.5 ± 0.8 g) per group were examined: 1) control, non-sensitized and non-trained (C); 2) ovalbumin sensitized (OA, 20 µg per mouse); 3) non-sensitized and trained at 50% maximum speed _ low intensity (PT50%); 4) non-sensitized and trained at 75% maximum speed _ moderate intensity (PT75%); 5) OA-sensitized and trained at 50% (OA+PT50%), 6) OA-sensitized and trained at 75% (OA+PT75%). There was no difference in muscle fiber cross-sectional area among groups and no difference in atrogin-1 and MuRF1 expression between C and OA groups. All exercised groups showed significantly decreased expression of atrogin-1 compared to C (1.01 ± 0.2-fold): PT50% = 0.71 ± 0.12-fold; OA+PT50% = 0.74 ± 0.03-fold; PT75% = 0.71 ± 0.09-fold; OA+PT75% = 0.74 ± 0.09-fold. Similarly significant results were obtained regarding MuRF1 gene expression compared to C (1.01 ± 0.23-fold): PT50% = 0.53 ± 0.20-fold; OA+PT50% = 0.55 ± 0.11-fold; PT75% = 0.35 ± 0.15-fold; OA+PT75% = 0.37 ± 0.08-fold. A short period of OA did not induce skeletal muscle atrophy in the mouse tibialis anterior muscle and aerobic training at low and moderate intensity negatively regulates the atrophy pathway in skeletal muscle of healthy mice or mice with allergic lung inflammation.FAPESPCNP

The effect of a low dose of clenbuterol on rat soleus muscle submitted to joint immobilization

The aim of the present study was to evaluate the effect of joint immobilization on morphometric parameters and glycogen content of soleus muscle treated with clenbuterol. Male Wistar (3-4 months old) rats were divided into 4 groups (N = 6 for each group): control, clenbuterol, immobilized, and immobilized treated with clenbuterol. Immobilization was performed with acrylic resin orthoses and 10 µg/kg body weight clenbuterol was administered subcutaneously for 7 days. The following parameters were measured the next day on soleus muscle: weight, glycogen content, cross-sectional area, and connective tissue content. The clenbuterol group showed an increase in glycogen (81.6%, 0.38 ± 0.09 vs 0.69 ± 0.06 mg/100 g; P < 0.05) without alteration in weight, cross-sectional area or connective tissue compared with the control group. The immobilized group showed a reduction in muscle weight (34.2%, 123.5 ± 5.3 vs 81.3 ± 4.6 mg; P < 0.05), glycogen content (31.6%, 0.38 ± 0.09 vs 0.26 ± 0.05 mg/100 mg; P < 0.05) and cross-sectional area (44.1%, 2574.9 ± 560.2 vs 1438.1 ± 352.2 µm²; P < 0.05) and an increase in connective tissue (216.5%, 8.82 ± 3.55 vs 27.92 ± 5.36%; P < 0.05). However, the immobilized + clenbuterol group showed an increase in weight (15.9%; 81.3 ± 4.6 vs 94.2 ± 4.3 mg; P < 0.05), glycogen content (92.3%, 0.26 ± 0.05 vs 0.50 ± 0.17 mg/100 mg; P < 0.05), and cross-sectional area (19.9%, 1438.1 ± 352.2 vs 1724.8 ± 365.5 µm²; P < 0.05) and a reduction in connective tissue (52.2%, 27.92 ± 5.36 vs 13.34 ± 6.86%; P < 0.05). Statistical analysis was performed using Kolmogorov-Smirnov and homoscedasticity tests. For the muscle weight and muscle glycogen content, two-way ANOVA and the Tukey test were used. For the cross-sectional area and connective tissue content, Kruskal-Wallis and Tukey tests were used. This study emphasizes the importance of anabolic pharmacological protection during immobilization to minimize skeletal muscle alterations resulting from disuse

Rat hindlimb joint immobilization with acrylic resin orthoses

The objective of the present study was to propose an orthosis of light material that would be functional for the animal and that would maintain only the ankle joint immobilized. Male Wistar rats (3 to 4 months old, 250-300 g) were divided into 2 groups (N = 6): control and immobilized for 7 days. Rats were anesthetized with sodium pentobarbital (40 mg/kg weight) and the left hindlimb was immobilized with the orthoses composed of acrylic resin model, abdominal belt and lateral supports. The following analyses were performed: glycogen content of the soleus, extensor digitorum longus, white gastrocnemius, red gastrocnemius, and tibialis anterior muscles by the phenol sulfuric method, and the weight, fiber area and intramuscular connective tissue of the soleus by the planimetric system. Data were analyzed statistically by the Kolmogorov-Smirnov, Student t and Wilcoxon tests. Immobilization decreased glycogen in all muscles (P < 0.05; soleus: 31.6%, white gastrocnemius: 56.6%, red gastrocnemius: 39%, extensor digitorum longus: 41.7%, tibialis anterior: 45.2%) in addition to reducing soleus weight by 34% (P < 0.05). Furthermore, immobilization promoted reduction of the fiber area (43%, P < 0.05) and increased the connective tissue (200%, P < 0.05). The orthosis model was efficient comparing with another alternative immobilization model, like plaster casts, in promoting skeletal muscle alterations, indicating that it could be used as a new model in other studies related to muscle disuse

Rat Skin Wound Healing Induced By Alternagin-c, A Disintegrin-like, Cys-rich Protein From Bothrops Alternatus Venom

Alternagin-C (ALT-C) is a disintegrin-like, Cys-rich protein isolated from Bothrops alternatus snake venom, which has been shown to induce in vivo angiogenesis. Therefore, this protein could be interesting as a new approach for tissue regeneration studies. Here the effects of ALT-C on fibroblasts and inflammatory cells, collagen type III and type I and TGF-α expression in a rat wounded skin model were studied. Thirty-five male Wistar rats (weight 270 ± 20 g) were divided into seven groups with five animals in each of the following groups: a control group which wounded animals received treatment with natrozol® gel only; ALT-C10, ALT-C60 and ALT-C100 groups of wounded animals that were treated with the same amount of gel containing 10, 60 and 100 ng of ALT-C, respectively. Animals were treated once a day with 20 μl of gel associated or not with ALT-C for 1, 3, 5 or 7 days. ALT-C treatment increased the fibroblast density, collagen deposition and accelerated the inflammatory process, mostly in the ALT-C60 group. These results indicate that ALT-C improves wound repair process in rat skin. Thus, ALT-C could be a candidate to the development of a novel therapeutic strategy for wounded skin repair. © 2011 The Authors. © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.83245252Singer, A.J., Clark, R.A., Cutaneous wound healing. (1999) N Engl J Med, 341, pp. 738-746Werner, S., Grose, R., Regulation of wound healing by growth factors and cytokines. (2003) Physiol Rev, 83, pp. 835-870Martin, P., Wound healing-aiming for perfect skin regeneration. (1997) Science, 276, pp. 75-81Clark, R.A., Basics of cutaneous wound repair. (1993) J Dermatol Surg Oncol, 19, pp. 693-706Schultz, G.S., Wysocki, A., Interactions between extracellular matrix and growth factors in wound healing. (2009) Wound Repair Regen, 17, pp. 153-162Tsahar, E., Moyer, J.D., Waterman, H., Barbacci, E.G., Bao, J., Levkowitz, G., Shelly, M., Yarden, Y., Pathogenic poxviruses reveal viral strategies to exploit the ErbB signaling network. (1998) EMBO J, 15, pp. 5948-5963Yang, X., Letterio, J.J., Lechleider, R.J., Chen, L., Hayman, R., Gu, H., Roberts, A.B., Deng, C., Targeted disruption of SMAD3 results in impaired mucosal immunity and diminished T cell responsiveness to TGF-beta. (1999) EMBO J, 18, pp. 1280-1291Strachan, L., Murison, J.G., Prestidge, R.L., Sleeman, M.A., Watson, J.D., Kumble, K.D., Cloning and biological activity of epigen, a novel member of the epidermal growth factor superfamily. (2001) J Biol Chem, 276, pp. 18265-18271Hashimoto, K., Regulation of keratinocyte function by growth factors. (2000) J Dermatol Sci, 24, pp. S46-S50Bennett, S.P., Griffiths, G.D., Schor, A.M., Leese, G.P., Schor, S.L., Growth factors in the treatment of diabetic foot ulcers. (2003) Br J Surg, 90, pp. 133-146Li, Y., Fan, J., Chen, M., Li, W., Woodley, D.T., Transforming growth factor-alpha: a major human serum factor that promotes human keratinocyte migration. (2006) J Invest Dermatol, 126, pp. 2096-2105Barrandon, Y., Green, H., Cell migration is essential for sustained growth of keratinocyte colonies: the roles of transforming growth factor-alpha and epidermal growth factor. (1987) Cell, 50, pp. 1131-1137Ellis, I.R., Schor, A.M., Schor, S.L., EGF AND TGF-α motogenic activities are mediated by the EGF receptor via distinct matrix-dependent mechanisms. (2007) Exp Cell Res, 313, pp. 732-741Kim, I., Mogford, J.E., Chao, J.D., Mustoe, T.A., Wound epithelialization deficits in the transforming growth factor-α knockout mouse. (2001) Wound Repair Regen, 9, pp. 386-390Mariano-Oliveira, A., Coelho, A.L., Terruggi, C.H., Selistre-de-Araújo, H.S., Barja-Fidalgo, C., De Freitas, M.S., Alternagin-C, a non-RGD-disintegrin, induces neutrophil migration via integrin signaling. (2003) Eur J Biochem, 270, pp. 4799-4808Selistre-de-Araujo, H.S., Cominetti, M.R., Terruggi, C.H., Mariano-Oliveira, A., De Freitas, M.S., Crepin, M., Figueiredo, C.C., Morandi, V., Alternagin-C, a disintegrin-like protein from the venom of Bothrops alternatus, modulates α2β1 integrin-mediated cell adhesion, migration and proliferation. (2005) Braz J Med Biol Res, 38, pp. 1505-1511Souza, D.H., Iemma, M.R., Ferreira, L.L., Faria, J.P., Oliva, M.L., Zingali, R.B., Niewiarowski, S., Selistre-de-Araujo, H.S., The disintegrin-like domain of the snake venom metalloprotease alternagin inhibits α2β1 integrin-mediated cell adhesion. (2000) Arch Biochem Biophys, 384, pp. 341-350Cominetti, M.R., Ribeiro, J.U., Fox, J.W., Selistre-de-Araujo, H.S., BaG, a new dimeric metalloproteinase/disintegrin from the Bothrops alternatus snake venom that interacts with α5β1 integrin. (2003) Arch Biochem Biophys, 416, pp. 171-179Ramos, O.H., Terruggi, C.H., Ribeiro, J.U., Cominetti, M.R., Figueiredo, C.C., Bérard, M., Crepin, M., Selistre-de-Araujo, H.S., Modulation of in vitro and in vivo angiogenesis by alternagin-C, a disintegrin-like protein from Bothrops alternatus snake venom and by a peptide derived from its sequence. (2007) Arch Biochem Biophys, 461, pp. 1-6Mesquita-Ferrari, R.A., Moraes, C.K., Micocci, K.C., Selistre-de-Araujo, H.S., ALT-C, a disintegrin-like Cys-rich protein from Bothrops alternatus, increases skeletal myoblast viability. (2009) J Venom Anim Toxins Incl Trop Disv, 15, pp. 325-339Durigan, J.L., Peviani, S.M., Russo, T.L., Delfino, G.B., Ribeiro, J.U., Cominetti, M.R., Selistre-de-Araujo, H.S., Salvini, T.F., Effects of alternagin-C from Bothrops alternatus on gene expression and activity of metalloproteinases in regenerating skeletal muscle. (2008) Toxicon, 52, pp. 687-694Sant'ana, E.M.C., Gouvêa, C.M.C.P., Nakaie, C.R., Selistre-de-Araújo, H.S., Angiogenesis and growth factor modulation induced by alternagin C, a snake venom disintegrin-like, cysteine-rich protein on a rat skin wound model. (2008) Arch Biochem Biophys, 479, pp. 20-27Junqueira, L.C.U., Cossermely, W., Brentani, R., Diferential staining of collagens type-I, Type-II and Type-III by picrosirius red and polarization microscopy. (1978) Arch Hist Jpn, 41, pp. 267-274Lapiere, C.M., Nusgens, B., Pierard, G.E., Interaction between collagen type I and type III in conditioning bundles organization. (1977) Connect Tissue Res, 5, pp. 21-29Robins, S.P., Milne, G., Duncan, A., Davies, C., Butt, R., Greiling, D., James, I.T., Increased skin collagen extractability and proportions of collagen type III are not normalized after 6 months healing of human excisional wounds. (2003) J Invest Dermatol, 121, pp. 267-272Witte, M., Barbul, A., General principles of wound healing. (1997) Surg Clin North Am, 77, pp. 509-528Terruggi, C.H.B., Cominetti, M.R., Bérard, M., Selistre-de-Araújo, H.S., The disintegrin alternagin-C modulates migration and viability of breast tumor cells. (2006) Rencontres en Toxinologie., pp. 201-8. , Toxines et cancer: LavoisierZigrino, P., Kamiguti, A.S., Eble, J., Drescher, C., Nischt, R., Fox, J.W., Mauch, C., The reprolysin jararhagin, a snake venom metalloproteinase, functions as a fibrillar collagen agonist involved in fibroblast cell adhesion and signaling. (2002) J Biol Chem, 277, pp. 40528-4053