The aim of the present study was to investigate the effects of exercises with different durations and intensities on mitochondrial autophagy and FUNDC1 in rat skeletal muscles. Sixty male Sprague-Dawley rats were randomly divided into 2- and 4-week control groups (Con), moderate-intensity exercise groups (M-ex groups, treadmill exercise, 16 m/min, 1 h/d, 6 d/week), and high-intensity exercise groups (Hi-ex groups, treadmill exercise, 35 m/min, 20 min/d, 6 d/week). The bilateral soleus muscles were separated after the intervention, and paraffin sections were prepared for transmission electron microscopy. ELISA method was used to detect the content of citrate synthase (CS). The co-localizations of microtubule-associated protein 1 light chain 3 (LC3)/cytochrome c oxidase IV (COX-IV), FUNDC1/COX-IV and LC3/FUNDC1 were observed by immunofluorescent staining in frozen sections. The skeletal muscle mitochondria were extracted, and the expression of autophagy-related proteins, including AMPKα, p-AMPKα, Unc-51 like kinase 1 (ULK1), FUNDC1, LC3 and p62, were detected by Western blot. The results showed that exercise increased mitochondrial function, i.e. peroxisome proliferator-activated receptor γ co-activator-1α (PGC-1α), COX-I protein expression levels and CS content. There was no difference of mitochondrial function parameters between 2-week M-ex and 2-week Hi-ex groups, while mitochondrial function of 4-weeks Hi-ex group was significantly lower than that of 4-week M-ex group. Under the same exercise intensity, mitochondrial autophagy activation in skeletal muscle of 4-week exercise was higher than that in 2-week exercise group; Under the same duration of exercise, mitochondrial autophagy activation of Hi-ex group was higher than that in M-ex group. Both 2- and 4-week exercise intervention increased LC3/COX-IV, COX-IV/FUNDC1, and FUNDC1/LC3 co-localizations. Exercise increased LC3-II/LC3-I ratio, down-regulated p62 protein expression level, up-regulated FUNDC1, ULK1 protein expression levels and AMPKα phosphorylation, and the changes of these proteins in 4-week Hi-ex group were significantly greater than those in 4-week M-ex group. These results suggest exercise induces mitochondrial autophagy in skeletal muscles, and the activity of autophagy is related to the duration and intensity of exercise. The induction mechanism of exercise may involve the mediation of FUNDC1 expression through AMPK-ULK1 pathway.
Animals ; Autophagy ; Exercise Therapy ; Humans ; Male ; Membrane Proteins/physiology* ; Mitochondria ; Mitochondrial Proteins/physiology* ; Muscle, Skeletal/metabolism* ; Rats ; Rats, Sprague-Dawley

PURPOSE: MicroRNAs are small non-coding RNAs that play important roles in vascular smooth muscle cell (VSMC) function. This study investigated the role of miR-379 on proliferation, invasion, and migration of VSMCs and explored underlying mechanisms thereof. MATERIALS AND METHODS: MicroRNA, mRNA, and protein levels were determined by quantitative real-time PCR and western blot. The proliferative, invasive, and migratory abilities of VSMCs were measured by CCK-8, invasion, and wound healing assay, respectively. Luciferase reporter assay was used to confirm the target of miR-379. RESULTS: Platelet-derived growth factor-bb was found to promote cell proliferation and suppress miR-379 expression in VSMCs. Functional assays demonstrated that miR-379 inhibited cell proliferation, cell invasion, and migration. Flow cytometry results further showed that miR-379 induced apoptosis in VSMCs. TargetScan analysis and luciferase report assay confirmed that insulin-like growth factor-1 (IGF-1) 3'UTR is a direct target of miR-379, and mRNA and protein levels of miR-379 and IGF-1 were inversely correlated. Rescue experiments showed that enforced expression of IGF-1 sufficiently overcomes the inhibitory effect of miR-379 on cell proliferation, invasion, and migration in VSMCs. CONCLUSION: Our results suggest that miR-379 plays an important role in regulating VSMCs proliferation, invasion, and migration by targeting IGF-1.
Apoptosis ; Cell Movement/*physiology ; Cell Proliferation/*physiology ; Humans ; Insulin ; Insulin-Like Growth Factor I/*physiology ; MicroRNAs/*physiology ; Muscle, Smooth, Vascular/*cytology ; Proto-Oncogene Proteins c-sis/*physiology ; RNA, Messenger/metabolism ; Real-Time Polymerase Chain Reaction ; Sincalide/physiology ; Wound Healing/physiology

Objective: To investigate whether androgens can regulate the expression of eNOS in rat corpus cavernosum through AKT3, PIK3CA, CALM, and CAV1 and influence erectile function. METHODS: Thirty-six 8-week-old male SD rats were randomly divided into groups A (4-week control), B (6-week control), C (4-week castration), D (6-week castration), E (4-week castration + testosterone replacement), and F (6-week castration + testosterone replacement). Both the testis and epididymis were removed from the rats in groups C, D, E and F, and on the second day after surgery, the animals of groups E and F were subcutaneously injected with testosterone propionate at 3 mg per kg of the body weight qd alt while all the others with isodose oil instead. At 4 weeks (for groups A, C and E) and 6 weeks (for groups B, D and F) after treatment, we detected the maximum intracavernous pressure (ICPmax), the mean carotid arterial pressure (MAP) and their ratio (ICPmax/MAP), measured the level of serum testosterone (T), and determined the expressions of eNOS, P-eNOS, AKT3, PIK3CA, CALM and CAV1 in the corpus cavernosum by Western blot and immunohistochemistry. RESULTS: No statistically significant differences were observed in the body weight and MAP among different groups. The serum T level and ICPmax/MAP were remarkably lower in groups C and D than in the other four groups (P<0.01) as well as in groups E and F than in A and B (P<0.05) but exhibited no significant differences either between E and F or between A and B. Immunohistochemistry showed that eNOS and P-eNOS were mainly expressed in the vascular endothelial cell membrane and cavernous vascular lumen, while AKT3, PIK3CA, CALM and CAV1 chiefly in the vascular endothelial cell cytoplasm and membrane, with a few in the smooth muscle cells. Western blot analysis manifested that the expressions of eNOS, P-eNOS, AKT3, PIK3CA, CALM and CAV1 were markedly lower in groups C and D than in A, B, E and F (P<0.01) as well as in D than in C (P<0.05) but those in groups E and F did not showed any significant difference from those in A and B, nor E from F or A from B. CONCLUSIONS Androgens can improve erectile function by upregulating the expressions of AKT3, PIK3CA, CALM and CAV1 protein molecules and activating eNOS after its phosphorylation, though the exact molecular mechanisms are yet to be further studied.
Animals ; Blood Pressure ; Blotting, Western ; Caveolin 1 ; metabolism ; Class I Phosphatidylinositol 3-Kinases ; metabolism ; Erectile Dysfunction ; Hormone Replacement Therapy ; Male ; Monomeric Clathrin Assembly Proteins ; metabolism ; Myocytes, Smooth Muscle ; Nitric Oxide Synthase Type III ; metabolism ; Orchiectomy ; Penile Erection ; physiology ; Penis ; enzymology ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Testosterone Propionate ; administration & dosage

OBJECTIVETo investigate the effect of KyoT2 on the proliferation and migration of airway smooth muscle cells (ASMCs) in mice with asthma.

METHODSOvalbumin (OVA) was used to establish the asthmatic model of airway remodeling in BALB/c mice. ASMCs were isolated and cultured, and primarily cultured ASMCs were used as the control group. The expression of KyoT2 in ASMCs was measured in the control and asthma groups. After the ASMCs from asthmatic mice were transfected with pCMV-Myc (empty vector group) or pCMV-Myc-KyoT2 plasmid with overexpressed KyoT2 (KyoT2 expression group) for 48 hours, RT-PCR and Western blot were used to measure the mRNA and protein expression of KyoT2, the MTT assay and BrdU assay were used to measure the proliferation of ASMCs, and Transwell assay was used to measure the migration of ASMCs. Western blot was used to determine the effect of KyoT2 overexpression on the protein expression of RBP-Jκ, PTEN, and AKT.

RESULTSCompared with the control group, the asthma group had significantly downregulated expression of KyoT2 in ASMCs, and the KyoT2 expression group had significantly upregulated expression of KyoT2 in ASMCs (P<0.05). Compared with the empty vector group, overexpressed KyoT2 significantly inhibited cell proliferation and migration, downregulated the expression of RBP-Jκ and AKT, and upregulated the expression of PTEN.

CONCLUSIONSOverexpressed KyoT2 can inhibit the proliferation and migration of ASMCs through the negative regulation of RBP-Jκ/PTEN/AKT signaling pathway.

Animals ; Asthma ; pathology ; Cell Movement ; Cell Proliferation ; Female ; Intracellular Signaling Peptides and Proteins ; physiology ; LIM Domain Proteins ; physiology ; Mice ; Mice, Inbred BALB C ; Muscle Proteins ; physiology ; Myocytes, Smooth Muscle ; physiology ; PTEN Phosphohydrolase ; physiology ; Trachea ; pathology

To investigate the effects and the underlying molecular mechanisms of curcumin on pulmonary artery smooth muscle cells in rat model with chronic obstructive pulmonary disease (COPD).A total of 75 male Wistar rats were randomly divided into control group (group CN), model group (group M), low-dose curcumin group (group CL), medium-dose curcumin group (group CM) and high-dose curcumin group (group CH). HE staining was used to observe the morphology of pulmonary artery. Proliferating cell nuclear antigen (PCNA), apoptosis-related protein Bcl-2 and Bax were detected by immunohistochemical staining. TUNEL kit was used to analyze the effects of curcumin on apoptosis of smooth muscle cells, and the protein expressions of SOCS-3/JAK2/STAT pathway in lung tissues were determined by western blot.Right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index (RVMI) in group M were significantly higher than those in group CN, group CH and group CM (all<0.05). HE staining and TUNEL kit test showed that the number of pulmonary artery smooth muscle cells had a significant increase in group M, while the pulmonary artery tube became thin, and the smooth muscle cells shrinked in group CM and group CH. Immunohistochemistry showed that PCNA and Bcl-2 in group M were significantly higher than those in group CN (all<0.05), while Bax expression was significantly lower than that in group CN (<0.05). PCNA in group CM and group CH were significantly lower than that in group M (all<0.05), while Bax expression was significantly higher than that in group M (<0.05). Western blot showed that SOCS-3 protein was significantly decreased in group M, while the p-JAK2, p-STAT1, p-STAT3 were significantly increased (all<0.05). Compared with group M, SOCS-3 protein in group CM and group CH were significantly increased (all<0.05), while the p-JAK2, p-STAT3 were significantly reduced (all<0.05).Curcumin could promote the apoptosis of smooth muscle cells in rats with COPD, and improve the mean pulmonary artery pressure and RVMI through stimulating SOCS-3/JAK2/STAT signaling pathway.
Animals ; Apoptosis ; drug effects ; physiology ; Arterial Pressure ; drug effects ; physiology ; Curcumin ; pharmacology ; Hypertrophy, Right Ventricular ; pathology ; physiopathology ; Janus Kinase 2 ; drug effects ; physiology ; Lung ; chemistry ; drug effects ; Male ; Myocytes, Smooth Muscle ; drug effects ; pathology ; Proliferating Cell Nuclear Antigen ; drug effects ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; drug effects ; metabolism ; Pulmonary Artery ; drug effects ; pathology ; Pulmonary Disease, Chronic Obstructive ; pathology ; physiopathology ; Rats ; Rats, Wistar ; STAT Transcription Factors ; Suppressor of Cytokine Signaling 3 Protein ; drug effects ; physiology ; Ventricular Pressure ; drug effects ; bcl-2-Associated X Protein ; drug effects ; metabolism

OBJECTIVETo determine the role of phosphatidylinositol 3-kinase--protein kinase B (PI3K-Akt) signaling pathway in the pro- tective effect of aerobic endurance training on the skeletal muscular mitochondria.

METHODSThirty-six rats were randomly divided into three groups( n = 12): control group, aerobic endurance training group and one-time exhaustive group. After the intervention, the quadriceps femoris muscle sample was obtained to detect the mitochondrial membrane potential( MMP), the activities of succinate dehydrogenase (SDH) and cy- tochrome coxidase (COX), and the protein levels of p-PI3K and p-Akt.

RESULTSCompared with the control group, the levels of mitochondrial membrane potential, the activities of succinate dehydrogenase and cytochrome coxidase, and the protein levels of p-PI3K and p-Akt were all significantly decreased in the one-time exhaustive group (P < 0.05). However, all the above was partially reversed in the endurance training group (P < 0.05), and there was no obvious difference with the control group (P > 0.05).

CONCLUSIONAerobic endurance training plays an important role in the protective effect on the skeletal muscular mitochondria, the mechanism may be related to activation PI3K-Akt signaling pathway.

Animals ; Electron Transport Complex IV ; metabolism ; Membrane Potential, Mitochondrial ; Mitochondria ; physiology ; Muscle, Skeletal ; physiology ; Phosphatidylinositol 3-Kinases ; metabolism ; Physical Conditioning, Animal ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Signal Transduction ; Succinate Dehydrogenase ; metabolism

Insulin resistance is the pathophysiological basis of many diseases. Overcoming early insulin resistance highly significant in prevention diabetes, non-alcoholic fatty liver, and atherosclerosis. The present study aimed at evaluating the therapeutic effects of baicalin on insulin resistance and skeletal muscle ectopic fat storage in high fat diet-induced mice, and exploring the potential molecular mechanisms. Insulin resistance in mice was induced with a high fat diet for 16 weeks. Animals were then treated with three different doses of baicalin (100, 200, and 400 mg·kg(-1)·d(-1)) for 14 weeks. Fasting blood glucose, fasting serum insulin, glucose tolerance test (GTT), insulin tolerance test (ITT), and skeletal muscle lipid deposition were measured. Additionally, the AMP-activated protein kinase/acetyl-CoA carboxylase and protein kinase B/Glycogen synthase kinase 3 beta pathways in skeletal muscle were further evaluated. Baicalin significantly reduced the levels of fasting blood glucose and fasting serum insulin and attenuated high fat diet induced glucose tolerance and insulin tolerance. Moreover, insulin resistance was significantly reversed. Pathological analysis revealed baicalin dose-dependently decreased the degree of the ectopic fat storage in skeletal muscle. The properties of baicalin were mediated, at least in part, by inhibition of the AMPK/ACC pathway, a key regulator of de novo lipogenesis and activation of the Akt/GSK-3β pathway, a key regulator of Glycogen synthesis. These data suggest that baicalin, at dose up to 400 mg·kg(-1)·d(-1), is safe and able to attenuate insulin resistance and skeletal muscle ectopic fat storage, through modulating the skeletal muscle AMPK/ACC pathway and Akt/GSK-3β pathway.
AMP-Activated Protein Kinases ; metabolism ; Acetyl-CoA Carboxylase ; metabolism ; Adipose Tissue ; metabolism ; Animals ; Diet, High-Fat ; Flavonoids ; pharmacology ; Glycogen Synthase Kinase 3 beta ; physiology ; Insulin Resistance ; Male ; Mice ; Mice, Inbred C57BL ; Muscle, Skeletal ; metabolism ; Proto-Oncogene Proteins c-akt ; physiology ; Signal Transduction ; physiology

BACKGROUNDAutophagy has been found to be involved in animal and cell models of atherosclerosis, but to date, it lacks general observation in human atherosclerotic plaques. Here, we investigated autophagy in smooth muscle cells (SMCs), endothelial cells (ECs), and macrophages in human atherosclerotic plaques via transmission electron microscopy (TEM), western blotting, and immunohistochemistry analysis.

METHODSThe histopathologic morphology of these plaques was observed via hematoxylin and eosin staining. The ultrastructural morphology of the SMCs, ECs, and macrophages in these plaques was observed via TEM. The localization of microtubule-associated protein 1 light chain 3 (MAP1-LC3), a relatively special maker of autophagy, in plaques was observed by double fluorescent immunochemistry and western blotting.

RESULTSAll of these human atherosclerotic plaques were considered advanced and unstable in histologically observation. By double fluorescent immunochemistry, the expression of LC3-II increased in the SMCs of the fibrous cap, the macrophages, and the microvascular ECs of the plaque shoulders. The protein level of LC3-II by western blotting significantly increased in plaques compared with normal controls. In addition, TEM observation of plaques revealed certain features of autophagy in SMCs, ECs, and macrophages including the formation of myelin figures, vacuolization, and the accumulation of inclusions in the cytosol. These results indicate that autophagy is activated in SMCs, ECs, and macrophages in human advanced atherosclerotic plaques.

CONCLUSIONSOur study is to demonstrate the existence of autophagy in human atherosclerotic plaques by different methods, which may contribute to the development of pharmacological approaches to stabilize vulnerable and rupture-prone lesions.

Atherosclerosis ; metabolism ; physiopathology ; Autophagy ; physiology ; Endothelial Cells ; pathology ; Humans ; In Vitro Techniques ; Microscopy, Electron, Transmission ; Microtubule-Associated Proteins ; metabolism ; Myocytes, Smooth Muscle ; pathology ; Plaque, Atherosclerotic ; metabolism ; physiopathology ; ultrastructure

The aim of this study was to investigate the inhibitory effect of heparin/fibronectin (Hep/Fn) complexes on neointimal hyperplasia following endovascular intervention. Hep/Fn complexes were immobilized onto titanium (Ti) surfaces, with subsequent X-ray photoelectron spectroscopy (XPS), Toluidine Blue O (TBO) and immunohistochemistry methods were used to characterize surface properties. Smooth muscle cell (SMC) cultures were used to evaluate the effect of Hep/Fn complexes on SMC proliferation. Results showed that Hep/Fn complexes successfully immobilized onto Ti surfaces and resulted in an inhibition of SMC proliferation. This study suggests that Hep/Fn surface-immobilized biomaterials develop as a new generation of biomaterials to prevent neointimal hyperplasia, particularly for use in cardiovascular implants.
Biocompatible Materials ; Cell Proliferation ; drug effects ; physiology ; Cells, Cultured ; Fibronectins ; chemistry ; pharmacology ; Heparin ; chemistry ; pharmacology ; Humans ; Immobilized Proteins ; chemistry ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; drug effects ; physiology ; Surface Properties ; Titanium ; chemistry ; Umbilical Arteries

To discuss the effect of puerarin (Pue) on the proliferation of hypoxia-induced pulmonary artery smooth muscle cells (PASMCs) and discuss whether the extracellular signal PI3K/AKT pathway was involved in the Pue-induced PASMC apoptosis. With the serum starvation group (SD group) as the control group, the MTT colorimetry method, Annexin V-FITC apoptosis detection kit and Western blot were used to detect Pue's effect on apoptosis of rat PASMCs. The protein immunoblot assay was used to detect whether PI3K/AKT pathway was involved in the inhibition of hypoxia-induced PASMC apoptosis process. The results show that under normoxic conditions, Pue had no effect on PASMC apoptosis; Under hypoxia conditions, Pue can inhibit PASMC apoptosis; Under normoxic and hypoxic conditions, Pue had no effect on TNF-α expression. Pue can reverse hypoxia-induced Bcl-2 (P <0.01), up-regulate it and down-regulated Bax (P <0.01). Under normoxic conditions, Pue had no effect on P-AKT expression. Both LY294002 and Pue can inhibit hypoxia-induced Bcl-2, up-regulation of P-AKT expression and down-regulation of Bax expression. Compared with the hypoxia + Pue group or the hypoxia + LY294002 group, the hypoxia + Pue + LY294002 group showed more significantly changes in Bcl-2, Bax, P-AKT expressions. The results show that, Pue can inhibit the hypoxic-induced PASMC apoptosis, which may be regulated through PI3K/AKT pathway.
Animals ; Apoptosis ; drug effects ; Cells, Cultured ; Chromones ; pharmacology ; Isoflavones ; pharmacology ; Morpholines ; pharmacology ; Myocytes, Smooth Muscle ; drug effects ; Phosphatidylinositol 3-Kinases ; physiology ; Proto-Oncogene Proteins c-akt ; physiology ; Pulmonary Artery ; cytology ; drug effects ; Rats ; Rats, Wistar ; Signal Transduction ; drug effects