This study investigated the influence of red light‐emitting diodes (LED, 630 nm) on different irradiation parameters and the number of applications on mesenchymal stem cells derived from adipose ...tissue (AdMSCs) metabolism and paracrine factors. The AdMSCs were irradiated with a LEDbox device (output power: 2452.5 mW; laser beam: 163.5 cm2; irradiance: 15 mW cm−2) using radiant exposures of 0.5, 2, and 4 J cm−2, respectively. AdMSCs were irradiated once or every 48 h up to three irradiations. All molecular analyses were performed 24 h after the last irradiation. LED did not induce changes in cell count, DNA damage, and oxidative stress. A significant repercussion of the LED has been noticed after three irradiations with 4 J cm−2. AdMSCs had higher levels of IL‐6, IGF‐1, and NOx index. A higher ATP content and MMT/Resazurin assay were identified in AdMSCs irradiated three times with 4 J cm−2. Mitochondrial basal respiration, maximal respiration and proton leak under metabolic stress were reduced by 0.5 and 2 J cm−2 irradiations. These data showed that three LED irradiations with 4 J cm−2 may be a suitable parameter for future AdMSCs therapy because of its improved metabolic activity, ATP content, and IL‐6, IGF‐1, and nitric oxide secretion.
Light‐emitting diodes box system used to irradiate AdMSCs culture flasks and promote biological effects with radiant exposure of 4 J cm−2. Interleukin‐6 (IL‐6); insulin‐like growth factor I (IGF‐1); index of nitric oxide (NOX).
Aim
To evaluate whether Porphyromonas gingivalis (P. gingivalis) inoculation could induce cardiac remodelling in rats.
Materials and Methods
The study was conducted on 33 Wistar rats, which were ...distributed in the following experimental groups: not inoculated; inoculated with 1 × 108 CFU/ml of bacteria; inoculated with 3 × 108 CFU/ml of bacteria. The animals were inoculated at baseline and on the 15th day of follow‐up. Blood collection was performed at baseline and 60 min after each inoculation. At 29 days, the animals were subjected to echocardiography and at 30 days to haemodynamic studies before sacrificing them.
Results
Impact of the bacteria was more evident in rats that received higher P. gingivalis concentration. Thus, 3 × 108 CFU/ml of bacteria increased the rectal temperature and water content in the lung as well as myocardial necrosis and fibrosis. P. gingivalis induced the intensification of DNA fragmentation and increased the levels of malondialdehyde, oxidized proteins, and macrophage expression in the myocardium. These findings were associated with lower LV isovolumetric relaxation time, +dP/dt, –dP/dt, and higher end‐diastolic pressure.
Conclusions
P. gingivalis bacteraemia is significantly associated with adverse cardiac remodelling and may play a biological role in the genesis of heart failure.
We investigated whether low-level laser therapy (LLLT) prior to or post resistance exercise could attenuate muscle damage and inflammation. Female Wistar rats were assigned to non-LLLT or LLLT ...groups. An 830-nm DMC Laser Photon III was used to irradiate their hind legs with 2J, 4J, and 8J doses. Irradiations were performed prior to or post (4J) resistance exercise bouts. Resistance exercise consisted of four maximum load climbs. The load work during a resistance exercise bout was similar between Control (non-LLLT, 225 ± 10 g), 2J (215 ± 8 g), 4J (210 ± 9 g), and 8J (226 ± 9 g) groups. Prior LLLT did not induce climbing performance improvement, but exposure to 4J irradiation resulted in lower blood lactate levels post-exercise. The 4J dose decreased creatine kinase and lactic dehydrogenase levels post-exercise regardless of the time of application. Moreover, 4-J irradiation exposure significantly attenuated tumor necrosis factor alpha, interleukin-6, interleukin-1beta, cytokine-induced neutrophil chemoattractant-1, and monocyte chemoattractant protein-1. There was minor macrophage muscle infiltration in 4J-exposed rats. These data indicate that LLLT prior to or post resistance exercise can reduce muscle damage and inflammation, resulting in muscle recovery improvement. We attempted to determine an ideal LLLT dose for suitable results, wherein 4J irradiation exposure showed a significant protective role.
Abstract This research investigated the duration of the influence of red light‐emitting diodes (LED, 630 nm; output power: 2452.5 mW; laser beam: 163.5 cm 2 ; irradiance: 15 mW/cm 2 ; radiant ...exposure: 4 J/cm 2 ) on different periods after irradiation (6, 12, 24, 48, and 72 h) on adipose‐derived mesenchymal stem cells' (AdMSCs) metabolism and paracrine factors. AdMSCs were irradiated three times every 48 h. Twenty‐four hours after the last irradiation, there was a higher MTT absorbance, followed by a decrease after 48 h. The cells' secretome showed increased levels of IL‐6 and VEGF after 12 and 24 h, but this was reversed after 48 h. Additionally, LED irradiation resulted in higher levels of nitrite and did not affect oxidative stress markers. LED irradiation had significant effects on AdMSCs after 24 h compared to other groups and its control group.
Preconditioning of cell recipients may exert a significant role in attenuating the hostility of the infarction milieu, thereby enhancing the efficacy of cell therapy. This study was conducted to ...examine whether exercise training potentiates the cardioprotective effects of adipose-derived stem cell (ADSC) transplantation following myocardial infarction (MI) in rats.
Four groups of female Fisher-344 rats were studied: Sham; non-trained rats with MI (sMI); non-trained rats with MI submitted to ADSCs transplantation (sADSC); trained rats with MI submitted to ADSCs (tADSC). Rats were trained 9 weeks prior to MI and ADSCs transplantation. Echocardiography was applied to assess cardiac function. Myocardial performance was evaluated in vitro. Protein expression analyses were carried out by immunoblotting. Periodic acid-Schiff staining was used to analyse capillary density and apoptosis was evaluated with terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay.
Echocardiography performed 4 weeks after the infarction revealed attenuated scar size in the both sADSC and tADSC groups compared to the sMI group. However, fractional shortening was improved only in the tADSC group. In vitro myocardial performance was similar between the tADSC and Sham groups. The expression of phosphoSer473Akt1 and VEGF were found to be higher in the hearts of the tADSC group compared to both the sADSC and sMI groups. Histologic analysis demonstrated that tADSC rats had higher capillary density in the remote and border zones of the infarcted sites compared to the sMI rats.
Preconditioning with exercise induces a pro-angiogenic milieu that may potentiate the therapeutic effects of ADSCs on cardiac remodelling following MI.
There was no data for cardiac repercussion of exercise training associated with tobacco smoking. This issue is interesting because some smoking people can be enrolled in an exercise-training program. ...Thus, we evaluated swimming training effects on the function and structural myocardial in rats exposed to tobacco smoking.
Male Wistar rats were assigned to one of four groups: C, untrained rats without exposure to tobacco smoking; E, exercised rats without exposure to tobacco smoking; CS, untrained rats exposed to tobacco smoking; ECS, exercised rats exposed to tobacco smoking. Rats swam five times a week twice daily (60min per session) for 8 weeks. Before each bout exercise, rats breathed smoke from 20 cigarettes for 60min. Twenty-four hours after the last day of the protocol, papillary muscles were isolated for in vitro analysis of myocardial mechanics. The myocardial mass and nuclear cardiomyocyte volume were used as hypertrophy markers, and collagen content was determined by picrosirius red staining.
There was a well-pronounced myocardial hypertrophic effect for two interventions. The exercise blunted myocardial collagen increases induced by tobacco smoking. However, exercise and tobacco-smoking association was deleterious to myocardial performance. Thereby, in vitro experiments with papillary muscles contracting in isometric showed impairment myocardial inotropism in exercised rats exposed to tobacco smoking.
This work presents novel findings on the role of exercise training on cardiac remodeling induced by tobacco smoking. Although exercise has mitigated tissue fibrosis, their association with tobacco smoking exacerbated hypertrophy and in vitro myocardial dysfunction.
This is first study to show that the association of an aerobic exercise training with tobacco smoking intensifies the phenotype of pathological cardiac hypertrophy. Therefore, the combination of interventions resulted in exacerbated myocardial hypertrophy and contractility dysfunction. These findings have significant clinical implication because some smoking people can be enrolled in an exercise-training program.
The post-myocardial infarction heart failure (HF) still carries a huge burden since current therapy is unsuccessful to abrogate poor prognosis. Thus, new approaches are needed, and photobiomodulation ...therapy (PBMt) may be a way. However, it is not known whether PBMt added to a standard HF therapy provides additional improvement in cardiac remodeling in infarcted rats. This study sought to determine the combined carvedilol-drug and PBMt with low-level laser therapy value in HF. Rats with large infarcts were treated for 30 days. The functional fitness was evaluated using a motorized treadmill. Echocardiography and hemodynamic measurements were used for functional evaluations of left ventricular (LV). ELISA, Western blot and biochemical assays were used to evaluate inflammation and oxidative stress in the myocardium. Carvedilol and PBMt had a similar action in normalizing pulmonary congestion and LV end-diastolic pressure, attenuating LV dilation, and improving LV systolic function. Moreover, the application of PBMt to carvedilol-treated rats inhibited myocardial hypertrophy and improved +dP/dt of LV. PBMt alone prevented inflammation with a superior effect than carvedilol. Carvedilol and PBMt normalized 4-hydroxynonenal (a lipoperoxidation marker) levels in the myocardium. However, importantly, the addition of PBMt to carvedilol attenuated oxidized protein content and triggered a high activity of the anti-oxidant catalase enzyme. In conclusion, these data show that the use of PBMt plus carvedilol therapy results in a significant additional improvement in HF in a rat model of myocardial infarction. These beneficial effects were observed to be due, at least in part, to decreased myocardial inflammation and oxidative stress.
High-intensity resistance exercise (RE) increases oxidative stress leading to deleterious effects on muscle performance and recovery. The aim of this study was to assess the effect of applying ...low-level laser therapy (LLLT) prior to a RE session on muscle oxidative stress and to determine the possible influence of the dosimetric parameters. Female Wistar rats were assigned to non-LLLT (Ctr: non-exercised control; RNI: RE) or LLLT groups subjected to RE (radiant energy: 4 J, 8 J, and 12 J, respectively). RE consisted of four maximum load climbs. An 830-nm DMC Lase Photon III was used to irradiate three points in gastrocnemius muscles (two limbs) before exercise. Animals were euthanized after 60 min after the end of the exercise, and muscle tissue was removed for analysis of oxidative stress markers. All doses resulted in the prevention of increased lipoperoxidation; however, LLLT prevented protein oxidation only in rats that were pretreated with 8 J and 12 J of energy by LLLT. RE and LLLT did not change catalase activity. However, RE resulted in lower superoxide dismutase activity, and the opposite was observed in the LLLT group. These data indicate that LLLT prior to RE can prevent muscle oxidative stress. This study is the first to evaluate the impact of dosimetric LLLT parameters on the oxidative stress induced by RE, wherein both 8 J and 12 J of energy afforded significant protection.
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