Moderate, but Not Excessive, Training Attenuates Autophagy Machinery in Metabolic Tissues.

The protective effects of chronic moderate exercise-mediated autophagy include the prevention and treatment of several diseases and the extension of lifespan. In addition, physical exercise may impair cellular structures, requiring the action of the autophagy mechanism for clearance and renovation of damaged cellular components. For the first time, we investigated the adaptations on basal autophagy flux in vivo in mice's liver, heart, and skeletal muscle tissues submitted to four different chronic exercise models: endurance, resistance, concurrent, and overtraining. Measuring the autophagy flux in vivo is crucial to access the functionality of the autophagy pathway since changes in this pathway can occur in more than five steps. Moreover, the responses of metabolic, performance, and functional parameters, as well as genes and proteins related to the autophagy pathway, were addressed. In summary, the regular exercise models exhibited normal/enhanced adaptations with reduced autophagy-related proteins in all tissues. On the other hand, the overtrained group presented higher expression of Sqstm1 and Bnip3 with negative morphological and physical performance adaptations for the liver and heart, respectively. The groups showed different adaptions in autophagy flux in skeletal muscle, suggesting the activation or inhibition of basal autophagy may not always be related to improvement or impairment of performance.

Excessive treadmill training enhances the insulin signaling pathway and glycogen deposition in mice hearts.

Exhaustive and chronic physical exercise leads to peripheral inflammation, which is one of the molecular mechanisms responsible for the impairment of the insulin signaling pathway in the heart. Recently, 3 different running overtraining models performed downhill (OTR/down), uphill (OTR/up), and without inclination (OTR) increased the serum levels of proinflammatory cytokines. This proinflammatory status induced insulin signaling impairment in the skeletal muscle; however, the response of this signaling pathway in the cardiac muscle of overtrained mice was still unknown. Thus, we investigated the effects of OTR/down, OTR/up, and OTR protocols on the protein levels of phosphorylation of insulin receptor ß (pIRß) (Tyr), phosphorylation of protein kinase B (pAkt) (Ser473), plasma membrane glucose transporter-1 (GLUT1) and GLUT4, phosphorylation of insulin receptor substrate-1 (pIRS-1) (Ser307), phosphorylation of IκB kinase α/ß) (pIKKα/ß (Ser180/181), phosphorylation of p38 mitogen-activated protein kinase (p-p38MAPK) (Thr180/Tyr182), phosphorylation of stress-activated protein kinases-Jun amino-terminal kinases (pSAPK-JNK) (Thr183/Tyr185), and glycogen content in mice hearts. The rodents were divided into naïve (N, sedentary mice), control (CT, sedentary mice submitted to performance evaluations), trained (TR, performed the training protocol), OTR/down, OTR/up, and OTR groups. After the grip force test, the cardiac muscles (ie, left ventricle) were removed and used for immunoblotting and histology. Although the OTR/up and OTR groups exhibited higher cardiac levels of pIRß (Tyr), only the OTR group exhibited higher cardiac levels of pAkt (Ser473) and plasma membrane GLUT4. On the contrary, the OTR/down group exhibited higher cardiac levels of pIRS-1 (Ser307). The OTR model enhanced the cardiac insulin signaling pathway. All overtraining models increased the left ventricle glycogen content, with this probably acting as a compensatory organ in response to skeletal muscle insulin signaling impairment.

Excessive training induces molecular signs of pathologic cardiac hypertrophy.

Chronic exercise induces cardiac remodeling that promotes left ventricular hypertrophy and cardiac functional improvement, which are mediated by the mammalian or the mechanistic target of rapamycin (mTOR) as well as by the androgen and glucocorticoid receptors (GRs). However, pathological conditions (i.e., chronic heart failure, hypertension, and aortic stenosis, etc.) also induce cardiac hypertrophy, but with detrimental function, high levels of proinflammatory cytokines and myostatin, elevated fibrosis, reduced adenosine monophosphate-activated protein kinase (AMPK) activation, and fetal gene reactivation. Furthermore, recent studies have evidenced that excessive training induced an inflammatory status in the serum, muscle, hypothalamus, and liver, suggesting a pathological condition that could also be detrimental to cardiac tissue. Here, we verified the effects of three running overtraining (OT) models on the molecular parameters related to physiological and pathological cardiac hypertrophy. C57BL/6 mice performed three different OT protocols and were evaluated for molecular parameters related to physiological and pathological cardiac hypertrophy, including immunoblotting, reverse transcription polymerase chain reaction, histology, and immunohistochemistry analyses. In summary, the three OT protocols induced left ventricle (LV) hypertrophy with signs of cardiac fibrosis and negative morphological adaptations. These maladaptations were accompanied by reductions in AMPKalpha (Thr172) phosphorylation, androgen receptor, and GR expressions, as well as by an increase in interleukin-6 expression. Specifically, the downhill running-based OT model reduced the content of some proteins related to the mTOR signaling pathway and upregulated the ß-isoform of myosin heavy-chain gene expression, presenting signs of LV pathological hypertrophy development.

Positive effects of total recovery period on anti- and pro-inflammatory cytokines are not linked to performance re-establishment in overtrained mice.

The association between excessive training sessions (i.e., overtraining/OT) and periods of inadequate recovery is linked to the nonfunctional overreaching (NFOR) state, which is defined as an unexplained decrement or stagnation of performance. The cytokine hypothesis of OT considers that pro-inflammatory cytokines are responsible by the NFOR state-induced performance decrement. Investigations using rodent models of OT verified increased levels of pro-inflammatory cytokines in hypothalamus, liver, serum and skeletal muscle samples. Recently, our research group observed that a 2-week total recovery period was not able to re-establish the NFOR state-induced performance decrement. As the responses of anti- and pro-inflammatory cytokines were not measured, we aimed to investigate the effects of 2-week total recovery period on the protein contents of IL-1beta, IL-6, IL-10, IL-15, TNF-alpha and SOCS-3 in serum and skeletal muscle samples of overtrained mice. Also, a bioinformatics analysis was performed to investigate the correlations of IL-1beta, IL-6, IL-10, IL-15, TNF-alpha and SOCS-3 in skeletal muscle with locomotor activity. In summary, the 2-week total recovery period upregulated the anti-inflammatory cytokines and normalized the pro-inflammatory cytokines without a concomitant re-establishment of performance.

Exhaustive Training Leads to Hepatic Fat Accumulation.

Recently, we demonstrated that an overtraining (OT) protocol for mice based on downhill running sessions increased the hepatic phosphorylation of 70-kDa ribosomal protein S6 kinase 1 (S6K1; Thr389), a downstream target of the mammalian target of rapamycin complex 1 (mTORC1). In liver, the overactivation of the Akt/mTORC1 pathway induces lipogenesis via regulation of the action of sterol regulatory element binding protein-1 (SREBP-1) at multiple steps. Herein, we verified the effects of three running OT models with same external load (i.e., the product between intensity and volume of training), but performed in downhill, uphill and without inclination, on the proteins related to the mTORC1 signaling pathway, the protein content of the SREBP-1, ACC, and FAS, and the morphological characteristics of C57BL/6 mouse livers. In summary, the downhill running-induced OT model up-regulated the levels of major proteins of the mTORC1 signaling pathway, the protein levels of SREBP-1 (p125 precursor) and induced signs of cell swelling accompanied by acute inflammation. The other two OT protocols performed uphill and without inclination did not modulate the most analyzed molecular proteins, but induced hepatic morphological alterations, suggesting an acute pathological adaptation. The three OT models induced hepatic fat accumulation. J. Cell. Physiol. 232: 2094-2103, 2017. © 2016 Wiley Periodicals, Inc.

Exercise alters the circadian rhythm of REV-ERB-α and downregulates autophagy-related genes in peripheral and central tissues.

The transcriptional repressor REV-ERB-α, encoded by Nuclear Receptor Subfamily 1 Group D Member 1 (Nr1d1), has been considered to play an essential role in the skeletal muscle oxidative capacity adaptation and muscle mass control. Also, this molecule regulates autophagy via the repression of autophagy-related genes both in skeletal muscle and brain regions. Classically, training programs based on endurance or strength characteristics enhance skeletal muscle mass content and/or oxidative capacity, leading to autophagy activation in several tissues. Thus, it seems that REV-ERB-α regulates similar responses induced by exercise. However, how this molecule responds to different exercise models/intensities in different tissues is still unclear. Therefore, the main aim was to characterize the responses of REV-ERB-α and autophagy-related genes to different exercise protocols (endurance/interval run/strength) in distinct tissues (gastrocnemius, soleus and hippocampus). Since REV-ERB-α presents a circadian rhythm, the analyses were performed in a time-course manner. The endurance and strength groups attenuated REV-ERB-α transcriptional response during the time course in gastrocnemius and soleus. Conversely, the interval group enhanced the Nr1d1 expression in the hippocampus. All protocols downregulated the REV-ERB-α protein levels in gastrocnemius following the exercise session with concomitant nuclear exclusion. The major autophagy-related genes presented downregulation after the exercise session in all analyzed tissues. Altogether, these results highlight that REV-ERB-α is extremely sensitive to physical exercise stimuli, including different models and intensities in skeletal muscle and the hippocampus.

Computed tomography-guided pericardiocentesis: a systematic review concerning contemporary evidence and future perspectives.

BACKGROUND: Pericardial effusion (PE) can develop in several pathological scenarios, and is often initially evaluated by means of echocardiography. Computed tomography (CT) has been used as an aid in the management of patients presenting with PE, in selected cases. The role of CT-guided pericardiocentesis in contemporary practice, however, remains not fully ascertained. We aimed at presenting a systematic review concerning the state-of-the-art of this technique. METHODS: A systematic review of published data on the use of CT for guiding pericardiocentesis was carried out (search performed on PubMed, ISI Web of Knowledge and Scopus databases). RESULTS: From title and abstract analysis, 14 articles were included that met the prespecified criteria. After full-text analysis, six articles were excluded. The eight articles under analysis included a total of 635 procedures performed in 571 patients. CT guidance was mostly used in a postoperative setting (364 procedures). Most procedures were done mainly for therapeutic purposes (528 procedures). Success rates ranged from 94% to 100%. Complications ranged from 0% to 7.8%. CONCLUSION: CT-guided pericardiocentesis is a useful technique in the approach to PE, in several clinical scenarios. Its use can be especially relevant in the postoperative period, as well as in individuals with suboptimal image quality (as assessed by echocardiography, for the moment the first choice in the approach to most cases of PE).

Levels of Hepatic Activating Transcription Factor 6 and Caspase-3 Are Downregulated in Mice after Excessive Training.

Recently, we demonstrated that different running overtraining (OT) protocols with the same external load, but performed downhill (OTR/down), uphill (OTR/up), and without inclination (OTR), led to hepatic fat accumulation. As the disruption of endoplasmic reticulum (ER) homeostasis is linked to animal models of fatty liver disease, we investigated the effects of these OT models on the proteins related to ER stress (i.e., BiP, inositol-requiring enzyme 1, protein kinase RNA-like endoplasmic reticulum kinase, eIF2alpha, ATF6beta, and glucose-regulated protein 94) and apoptosis (C/EBP-homologous protein, Caspase-3, 4, and 12, Bax, and tumor necrosis factor receptor-associated factor 2) in livers of C57BL/6 mice. Also, aerobic training can attenuate cardiac ER stress and improve exercise capacity. Therefore, we investigated whether the decrease in performance induced by our OT protocols is linked to ER stress and apoptosis in mouse hearts. The rodents were divided into six groups: naïve (N, sedentary mice), control (CT, sedentary mice submitted to the performance evaluations), trained (TR), OTR/down, OTR/up, and OTR groups. Rotarod, incremental load, exhaustive, and grip force tests were used to evaluate performance. After the grip force test, the livers and cardiac muscles (i.e., left ventricle) were removed and used for immunoblotting. All of the OT protocols led to similar responses in the performance parameters and displayed significantly lower hepatic ATF6beta values compared to the N group. The OTR/down group exhibited lower liver cleaved caspase-3 values compared to the CT group. However, the other proteins related to ER stress and apoptosis were not modulated. Also, the cardiac proteins related to ER stress and apoptosis were not modulated in the experimental groups. In conclusion, the OT protocols decreased the levels of hepatic ATF6beta, and the OTR/down group decreased the levels of hepatic cleaved caspase-3. Also, the decrease in performance induced by our OT models is not associated with ER stress and apoptosis in mice hearts.

Nonfunctional overreaching and hepatic adaptations of APPL1 and APPL2

Abstract AIMS Previously, we verified that overtrained mice upregulated the TRB3 levels, its association with Akt, and the hepatic concentrations of glycogen. It is known that APPL1 can limit the interaction between TRB3 and Akt, playing an important role in the glucose homeostasis. Thus, we verified the effects of three overtraining protocols on the hepatic levels of APPL1 and APPL2. METHODS Rodents were divided into control (CT), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up) and overtrained by running without inclination (OTR). The hepatic contents of APPL1 and APPl2 were measured by the immunoblotting technique. RESULTS Significant elevation of APPL1 observed in the OTR/down and OTR/up groups, as well as the tendency of increase (p=0.071) observed in the OTR group. CONCLUSION These results indicate that this particular protein is likely to participate in the glucose homeostasis previously observed in response to these OT protocols.(AU)

Hypothalamic endoplasmic reticulum stress of overtrained mice after recovery

Abstract AIMS knowing the relationship between endoplasmic reticulum (ER) stress and inflammation and based on the fact that downhill running-based overtraining (OT) model increases hypothalamus levels of some pro-inflammatory cytokines, we verified the effects of three OT protocols on the levels of BiP, pIRE-1 (Ser734), pPERK (Thr981), pelF2alpha (Ser52), ATF-6 and GRP-94 proteins in the mouse hypothalamus after two weeks of recovery. METHODS the mice were randomized into control (CT), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up) and overtrained by running without inclination (OTR) groups. After 2-week total recovery period (i.e., week 10), hypothalamus was removed and used for immunoblotting. RESULTS the OTR/down group exhibited high levels of BiP and ATF6. The other OT protocols showed higher levels of pPERK (Th981) and pelf-2alpha (Ser52) when compared with the CT group. CONCLUSION the current results suggest that after a 2-week total recovery period, the overtrained groups increased partially their ER stress protein levels, but without hypothalamic inflammation, which characterizes a physiological condition related to an adaptation mechanism.(AU)