Anti-apoptotic and pro-survival effects of exercise training on hypertensive hearts

Evaluation of skeletal muscle function in male rats with doxorubicin-induced myopathy following various exercise techniques: the significant role of glucose transporter 4

A common anthracycline antibiotic used to treat cancer patients is doxorubicin (DOX). One of the effects of DOX therapy is skeletal muscle fatigue. Our goal in this research was to study the beneficial effect of exercise on DOX-induced damaged muscle fibers and compare the effect of different exercise strategies (prophylactic, post- toxicity and combined) on DOX toxicity. Five groups were created from 40 male rats: group I, control group; group II, DOX was administered intraperitoneally for 2 weeks over 6 equal injections (each 2.5 mg/kg); group III, rats trained for 3 weeks before DOX; group IV, rats trained for 8 weeks after DOX; and group V, rats were trained for 3 weeks before DOX followed by 8 weeks after. Measures of oxidative damage (H2O2, catalase), inflammation (TNF-α), and glucose transporter 4 (GLUT4) expression on skeletal muscle were assessed. Also, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was estimated. Skeletal performance was evaluated by contraction time (CT), half relaxation time (1/2 RT), and force-frequency relationship by the end of this research. The current study demonstrated a detrimental effect of DOX on skeletal performance as evidenced by a significant increase in CT and 1/2 RT compared to control; in addition, H2O2, TNF-α, and HOMA-IR were significantly increased with a significant decrease in GLUT4 expression and catalase activity. Combined exercise therapy showed a remarkable improvement in skeletal muscle performance, compared to DOX, CT, and 1/2 RT which were significantly decreased; H2O2 and TNF-α were significantly decreased unlike catalase antioxidant activity that significantly increased; in addition, skeletal muscle glucose metabolism was significantly improved as GLUT4 expression significantly increased and HOMA-IR was significantly decreased. Exercise therapy showed significant improvement in all measured parameters relative to DOX. However, combined exercise therapy showed the best improvement relative to both pre-exercise and post-exercise groups.

The Effect of Different Exercise Modalities on Sertoli-germ Cells Metabolic Interactions in High-fat Diet-induced Obesity Rat Models: Implication on Glucose and Lactate Transport, Igf1, and Igf1R-dependent Pathways

The study aimed to uncover a unique aspect of obesity-related metabolic disorders in the testicles induced by a high-fat diet (HFD) and explored the potential mitigating effects of exercise modalities on male fertility. Thirty mature male Wistar rats were randomly assigned to control, HFD-sole, moderate-intensity exercise with HFD (HFD+MICT), high-intensity continuous exercise with HFD (HFD+HICT), and high-intensity interval exercise with HFD (HFD+HIIT) groups (n=6/group). Intracytoplasmic carbohydrate (ICC) storage, expression levels of GLUT-1, GLUT-3, MCT-4, Igf1, and Igf1R, and testicular lactate and lactate dehydrogenase (LDH) levels were assessed. ICC storage significantly decreased in HFD-sole rats, along with decreased mRNA and protein levels of GLUT-1, GLUT-3, MCT-4, Igf1, and Igf1R. The HFD-sole group exhibited a notable reduction in testicular lactate and LDH levels (p<0.05). Conversely, exercise, particularly HIIT, upregulated ICC storage, expression levels of GLUT-1, GLUT-3, MCT-4, Igf1, and Igf1R, and enhanced testicular lactate and LDH levels. These results confirm that exercise, especially HIIT, has the potential to mitigate the adverse effects of HFD-induced obesity on testicular metabolism and male fertility. The upregulation of metabolite transporters, LDH, lactate levels, Igf1, and Igf1R expression may contribute to maintaining metabolic interactions and improving the glucose/lactate conversion process. These findings underscore the potential benefits of exercise in preventing and managing obesity-related male fertility issues.

Rewiring of IGF1 secretion and enhanced IGF1R signaling induced by co-chaperone carboxyl-terminus of Hsp70 interacting protein in adipose-derived stem cells provide augmented cardioprotection in aging-hypertensive rats

Aging-associated cardiovascular diseases depend on the longitudinal deterioration of stem cell dynamics. The entire mechanism behind it is not completely understood. However, many studies suggest that endocrine pathways, particularly the insulin-like growth factor-1(IGF1) signaling pathway are involved in cardioprotection, especially in stem-cell treatments. Here, we investigated the role of a co-chaperone, carboxyl-terminus of Hsp70 interacting protein (CHIP) in the aspects of growth factor secretion and receptor stabilization in mesenchymal stem cells (MSCs). Briefly, we overexpressed CHIP in rat adipose-derived stem cells (rADSCs) and explored the consequences in vitro, and in vivo, in spontaneously hypertensive rats (SHR). Our data revealed that CHIP overexpression in rADSCs promoted the secretion of insulin-like growth factor-1 (IGF1) and IGF binding protein-3 (IGFBP3) as per immunoblot/cytokine array analysis. We also found that these results were dependent on the nuclear translocation of signal transducer and activator of transcription 3 (STAT3) in rADSCs. Further, the CHIP co-chaperone was also involved in the stabilization of the receptor of IGF1 (IGF1R); interactions between the beta transmembrane region of IGF1R, and the tetracopeptide repeat (TPR) domain of CHIP were evident. Importantly, after the transplantation of lentiviral CHIP overexpression of rADSCs (rADSCsCHIP-WT) into nine months aging-SHR led to an increase in their cardiac function - increased ejection fraction and fractional shortening (≈15% vs. control SHR) - as well as a decrease in their heart size and heart rate, respectively. Altogether, our results support the use of CHIP overexpressing stem cells for the mitigation of cardiac hypertrophy and remodeling associated with late-stage hypertension.

The Enhanced Effects of Swimming and Running Preconditioning in an Experimental Model of Myocardial Ischemia/Reperfusion Injury

Background and Objectives: This study was conducted to examine the influence of different swimming and running protocols as forms of physiological preconditioning on an isolated rat heart's ischemia/reperfusion injury. Materials and Methods: This study was conducted on 60 male Wistar albino rats (6 weeks old, bw: 200 ± 20 g), divided into: CTRL group-a sedentary control group; sAeT-a group that underwent aerobic swimming conditioning using a swimming protocol for 8 weeks; sAnT-a group that underwent anaerobic swimming conditioning; rAeT-a group that underwent aerobic running conditioning; and rAnT-a group that underwent anaerobic running conditioning. After the preconditioning protocols, ex vivo estimating of myocardial function according to the Langendorff technique was performed. Results: The anaerobic running training decreased heart rate and the anaerobic swimming training reduced coronary flow, demonstrating the difference in the physiological heart response of aerobic/anaerobic physical training (p < 0.05). Heart rate was significantly reduced in both training swimming groups after a period of ischemia (p < 0.05). On the other hand, the anaerobic running protocol induced a significantly decreased heart rate in comparison with the aerobic running group and the sedentary group (p < 0.05). Conclusions: The data from this experimental study support many protective training effects, i.e., improved contractility, improved resting heart rate, and increased physical work capacity and exercise tolerance. Physical training in the form of anaerobic running induces greater heart preconditioning for reperfusion injury in comparison with anaerobic swimming training.

The Multi-Faceted Nature of Renalase for Mitochondrial Dysfunction Improvement in Cardiac Disease

The cellular mechanisms and signaling network that guide the cardiac disease pathophysiology are inextricably intertwined, which explains the current scarcity of effective therapy and to date remains the greatest challenge in state-of-the-art cardiovascular medicine. Accordingly, a novel concept has emerged in which cardiomyocytes are the centerpiece of therapeutic targeting, with dysregulated mitochondria as a critical point of intervention. Mitochondrial dysfunction pluralism seeks a multi-faceted molecule, such as renalase, to simultaneously combat the pathophysiologic heterogeneity of mitochondria-induced cardiomyocyte injury. This review provides some original perspectives and, for the first time, discusses the functionality spectrum of renalase for mitochondrial dysfunction improvement within cardiac disease, including its ability to preserve mitochondrial integrity and dynamics by suppressing mitochondrial ΔΨm collapse; overall ATP content amelioration; a rise of mtDNA copy numbers; upregulation of mitochondrial genes involved in oxidative phosphorylation and cellular vitality promotion; mitochondrial fission inhibition; NAD⁺ supplementation; sirtuin upregulation; and anti-oxidant, anti-apoptotic, and anti-inflammatory traits. If verified that renalase, due to its multi-faceted nature, behaves like the "guardian of mitochondria" by thwarting pernicious mitochondrial dysfunction effects and exerting therapeutic potential to target mitochondrial abnormalities in failing hearts, it may provide large-scale benefits for cardiac disease patients, regardless of the underlying causes.

Association of physical activity with increased PI3K and Akt mRNA levels in adipose tissues of obese and non-obese adults

Phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway regulates glucose and lipid metabolism. We examined the association of PI3K and Akt expression in visceral (VAT) and subcutaneous adipose tissue (SAT) with daily physical activity (PA) in non-diabetic obese and non-obese adults. In this cross-sectional study, we included 105 obese (BMI ≥ 30 kg/m²) and 71 non-obese (BMI < 30 kg/m²) subjects (aged/ ≥ 18 years). PA was measured using a valid and reliable International Physical Activity Questionnaire(IPAQ)-long-form, and the metabolic equivalent of task(MET) was calculated. Real-time PCR was performed to analyze the mRNA relative expression. VAT PI3K expression had a lower level in obese compared to non-obese (P = 0.015), while its expression was higher in active individuals than inactive ones (P = 0.029). SAT PI3K expression was increased in active individuals compared to inactive ones (P = 0.031). There was a rise in VAT Akt expression in the actives compared to the inactive participants (P = 0.037) and in non-obese/active compared to non-obese/inactive individuals (P = 0.026). Obese individuals had a decreased expression level of SAT Akt compared to non-obsesses (P = 0.005). VAT PI3K was directly and significantly associated with PA in obsesses (β = 1.457, P = 0.015). Positive association between PI3K and PA suggests beneficial effects of PA for obese individuals that can be partly described by PI3K/Akt pathway acceleration in adipose tissue.

Anti-apoptotic and anti-fibrotic efficacy of exercise training in hypertensive hearts: A systematic review

Background

This review aims to summarize the antiapoptotic, pro-survival, and antifibrotic effects of exercise training in hypertensive hearts.

Methods

Keyword searches were conducted in PubMed, Web of Science, and Scopus in May 2021. Research published in English on the effects of exercise training on the apoptosis, survival, and fibrosis pathways in hypertension was included. The CAMARADES checklist was used to determine the quality of the studies. Two reviewers independently implemented predesigned protocols for the search and selection of studies, the assessment of study quality, and the evaluation of the strength of evidence.

Results

Eleven studies were included after selection. The duration of the exercise training ranged from 5 to 27 weeks. Nine studies showed that exercise training improved cardiac survival rates by increasing IGF-1, IGF-1 receptor, p-PI3K, Bcl-2, HSP 72, and p-Akt. Furthermore, 10 studies showed that exercise training reduced apoptotic pathways by downregulating Bid, t-Bid, Bad, Bak, Bax, TNF, and FADD. Finally, two studies reported the modification and subsequent improvement of physiological characteristics of fibrosis and decreased MAPK p38 and PTEN levels by exercise training in the left ventricle of the heart.

Conclusions

The findings of the review showed that exercise training could improve cardiac survival rates and attenuate cardiac apoptotic and fibrotic pathways in hypertension, suggesting that exercise training could act as a therapeutic approach to prevent hypertension-induced cardiac apoptosis and fibrosis.

Systematic Review Registration

https://www.crd.york.ac.uk, identifier: CRD42021254118.

Left Ventricular Diastolic Response to Isometric Handgrip Exercise in Physically Active and Sedentary Individuals

Aims: This study aims to investigate the diastolic left ventricular (LV) response to isometric handgrip exercise among healthy middle-aged men with high physical activity levels, versus matched sedentary individuals. Methods: Two groups of 10 men aged 41−51 years were studied. Men in the first group had high weekly self-reported physical activity levels (>3000 METs × min/week). In comparison, men in the second group reported low physical activity levels (<300 METs × min/week). An isometric handgrip exercise (IHE) stress echocardiography test was performed in all of them. Results: Both groups showed a similar and statistically significant increase in heart rate, systolic, diastolic, and mean arterial pressure following IHE. The group of active men under study did not show a statistically significant change in the ratio of early diastolic mitral valve inflow velocity to early diastolic lateral wall tissue velocity (E/e’ ratio) in response to IHE. Conversely, the inactive participants’ E/e’ ratio was higher at peak activity in the isometric handgrip exercise. Conclusions: Apparently, healthy middle-aged men with high levels of physical activity seem to have an improved lusitropic cardiac function compared to men with low levels of physical activity, as observed by the different diastolic LV responses induced by isometric handgrip exercise.

Angiotensin II Receptor Blocker Irbesartan Enhanced SIRT1 longevity Signaling Replaces the Mitochondrial Biogenetic Survival Pathway to Attenuate Hypertension-Induced Heart Apoptosis

Background: The present study investigated whether angiotensin II type 1 receptor blocker irbesartan (ARB) and partial agonist of PPAR-γ prevents heart apoptosis by suppressing cardiac Fas/FasL-mediated to mitochondria-mediated apoptosis in the hearts of hypertensive rat model. Methods: Cardiac function using echocardiography, H&E staining, TUNEL assay, and Western blotting were measured in the excised hearts from three groups, i.e., an untreated hypertensive group (SHR), an ARB-treated hypertensive group (50 mg/kg/day, S.C., SHR-ARB), and untreated normotensive Wistar-Kyoto rats (WKY). Results: Fas Ligand, Fas death receptors, FADD, active caspase-8, active caspase-3 (Fas/FasL-mediated apoptotic pathway), as well as Bax, cytochrome c, active caspase-9 and -3 (mitochondria-mediated apoptotic pathway), IGF-II, and p-JNK were decreased in SHR-ARB group when compared with the SHR group. SIRT1, PGC-1α, Bcl2, and Bcl-xL (SIRT1/PGC-1α pro-survival pathway) were increased in the SHR-ARB group when compared with the SHR group. Conclusions: Our findings suggested that the ARB might prevent cardiac Fas/FasL-mediated to mitochondria-mediated apoptosis pathway in the hypertensive model associated with IGF-II, p-JNK deactivation, and SIRT1/PGC-1α pro-survival pathway upregulation. ARB prevents hypertension-enhanced cardiac apoptosis via enhancing SIRT1 longevity signaling and enhances the mitochondrial biogenetic survival pathway.

Exercise-induced signaling pathways to counteracting cardiac apoptotic processes

Cardiovascular diseases are the most common cause of death in the world. One of the major causes of cardiac death is excessive apoptosis. However, multiple pathways through moderate exercise can reduce myocardial apoptosis. After moderate exercise, the expression of anti-apoptotic proteins such as IGF-1, IGF-1R, p-PI3K, p-Akt, ERK-1/2, SIRT3, PGC-1α, and Bcl-2 increases in the heart. While apoptotic proteins such as PTEN, PHLPP-1, GSK-3, JNK, P38MAPK, and FOXO are reduced in the heart. Exercise-induced mechanical stress activates the β and α5 integrins and subsequently, focal adhesion kinase phosphorylation activates the Akt/mTORC1 and ERK-1/2 pathways, leading to an anti-apoptotic response. One of the reasons for the decrease in exercise-induced apoptosis is the decrease in Fas-ligand protein, Fas-death receptor, TNF-α receptor, Fas-associated death domain (FADD), caspase-8, and caspase-3. In addition, after exercise mitochondrial-dependent apoptotic factors such as Bid, t-Bid, Bad, p-Bad, Bak, cytochrome c, and caspase-9 are reduced. These changes lead to a reduction in oxidative damage, a reduction in infarct size, a reduction in cardiac apoptosis, and an increase in myocardial function. After exercising in the heart, the levels of RhoA, ROCK1, Rac1, and ROCK2 decrease, while the levels of PKCε, PKCδ, and PKCɑ are activated to regulate calcium and prevent mPTP perforation. Exercise has an anti-apoptotic effect on heart failure by increasing the PKA-Akt-eNOS and FSTL1-USP10-Notch1 pathways, reducing the negative effects of CaMKIIδ, and increasing the calcineurin/NFAT pathway. Exercise plays a protective role in the heart by increasing HSP20, HSP27, HSP40, HSP70, HSP72, and HSP90 along with increasing JAK2 and STAT3 phosphorylation. However, research on exercise and factors such as Pim-1, Notch, and FAK in cardiac apoptosis is scarce, so further research is needed. Future research is recommended to discover more anti-apoptotic pathways. It is also recommended to study the synergistic effect of exercise with gene therapy, dietary supplements, and cell therapy for future research.

Aerobic Exercise Training Improves Renal Injury in Spontaneously Hypertensive Rats by Increasing Renalase Expression in Medulla

We aimed to examine the effects of aerobic exercise training on renal function in spontaneously hypertensive rats (SHR) and elucidate their possible mechanisms. Adult male SHR and age-matched Wistar-Kyoto rats (WKY) were divided into four groups: WKY sedentary group, SHR sedentary group, low-intensity training group, and medium-intensity training group. Using molecular and biochemical approaches, we investigated the effects of 14-week training on renalase (RNLS) protein levels, renal function, and apoptosis and oxidative stress modulators in kidney tissues. In vitro, angiotensin II (Ang II)-induced human kidney proximal epithelial cells (HK-2) were treated with RNLS, and changes in apoptosis and oxidative stress levels were observed. Our results show that moderate training improved renal function decline in SHR. In addition, aerobic exercise therapy significantly increased levels of RNLS in the renal medulla of SHR. We observed in vitro that RNLS significantly inhibited the increase of Ang II-inducedapoptosis and oxidative stress levels in HK-2. In conclusion, aerobic exercise training effectively improved renal function in SHR by promoting RNLS expression in the renal medulla. These results explain the possible mechanism in which exercise improves renal injury in hypertensive patients and suggest RNLS as a novel therapy for kidney injury patients.

Resveratrol and regular exercise may attenuate hypertension-induced cardiac dysfunction through modulation of cellular stress responses

AIMS

Hypertension is one of the major causes of cardiac damage. In this study, the effects of resveratrol supplementation and regular exercise on hypertension-induced cellular stress responses of myocardium were compared.

MAIN METHODS

Hypertension was induced in male Wistar rats by deoxycorticosterone-acetate + salt administration for 12 weeks. Resveratrol and regular exercise were applied for the last six weeks. In addition to biochemical and molecular examinations, isoprenaline, phenylephrine and, acetylcholine-mediated contractions and sinus rate were recorded in the isolated cardiac tissues.

KEY FINDINGS

Resveratrol and regular exercise reduced systolic blood pressure in hypertensive rats. The altered adrenergic and cholinergic responses of the right atrium and left papillary muscles in hypertension were separately improved by resveratrol and regular exercise. Resveratrol and regular exercise decreased plasma and cardiac total antioxidant capacity and, augmented the expression of antioxidant genes in hypertensive rats. While regular exercise restored the increase in p-PERK expression associated with endoplasmic reticulum stress and decrease in mitophagic marker PINK1 expression, resveratrol only ameliorated PINK1 expression in hypertensive rats. Resveratrol and exercise training suppressed hypertension-induced NLRP3 inflammasome activation by reversing the increase in NLRP3, p-NF-κB expression and the mature-IL-1β/pro-IL-1β and cleaved-caspase-1/pro-caspase-1 ratio. Resveratrol and exercise enhanced mRNA expression of caspase-3, bax, and bcl-2 involved in the apoptotic pathway, but attenuated phosphorylation of stress-related mitogenic proteins p38 and JNK induced by hypertension.

SIGNIFICANCE

Our study demonstrated the protective effect of resveratrol and exercise on hypertension-induced cardiac dysfunction by modulating cellular stress responses including oxidative stress, ER stress, mitophagy, NLRP3 inflammasome-mediated inflammation, and mitogenic activation.

Swimming training modulates lung injury induced by ovariectomy in diabetic rats: involvement of inflammatory and fibrotic biomarkers

CONTEXT

Previous studies have noted that the incidence of inflammatory and fibrotic diseases is higher in diabetic menopausal women.

OBJECTIVE

In the present study, we evaluated effects of swimming training on inflammatory and fibrotic biomarkers in the lung of ovariectomized diabetic rats.

MATERIALS AND METHODS

Forty female rats were assigned into four groups: sham; rats underwent surgery without ovariectomies, OVX: rats that underwent ovariectomies, OVX.Dia: ovariectomized rats with high-fat diet, OVX.Dia. Exe: ovariectomized diabetic rats with 8 weeks of swimming training. At the end of experiment, protein expressions were assessed with western blot. Lung sections were subjected to immunohistochemical and haematoxylin eosin staining.

RESULTS

There was a significant difference in the protein expressions between exercise and ovariectomized diabetic groups (p < .05).

CONCLUSION

The present study showed strong potential of swimming training on oestrogen deficient diabetic lung. These data encourage further investigation into the inclusive effects of exercise in menopausal diabetic women.

Anti-apoptotic effects of diosgenin on ovariectomized hearts

BACKGROUND

The anti-apoptotic effects of diosgenin, a steroid saponin, on hearts in female with estrogen deficiency have been less studied. This study aimed to evaluate the anti-apoptotic effects of diosgenin on cardiac widely dispersed apoptosis in a bilateral ovariectomized animal model.

METHODS

A total of 60 female Wistar rats, aged 6-7 months, were divided into the sham-operated group (Sham), bilateral ovariectomized rats for 2 months, and ovariectomized rats administered with 0, 10, 50, or 100 mg/kg diosgenin daily (OVX, OVX 10, OVX 50, and OVX 100, respectively) in the second month. The excised hearts were analyzed by H&E staining, TUNEL(+) assays and Western Blot.

RESULT

Cardiac TUNEL(+) apoptotic cells, the levels of Fas ligand, Fas death receptors, Fas-associated death domain, active caspase-8, and active caspase-3 (FasL/Fas-mediated pathways) as well as the levels of Bax, Bad, Bax/Bcl2, Bad/p-Bad, cytosolic Cytochrome c, active caspase-9, and active caspase-3 (mitochondria-initiated pathway) were increased in OVX compared with Sham group but those were decreased in OVX 50 compared with OVX.

CONCLUSION

Diosgenin appeared to prevent or suppress ovariectomy-induced cardiac FasL/Fas-mediated and mitochondria-initiated apoptosis. These findings might provide one of the possible therapeutic approaches of diosgenin for potentially preventing cardiac apoptosis in women after bilateral ovariectomy or women with estrogen deficiency.

Potential Role of Exercise in Regulating YAP and TAZ During Cardiomyocytes Aging

Adaptation of cardiac muscle to regular exercise results in morphological and structural changes known as physiological cardiac hypertrophy, to which the Hippo signaling pathway might have contributed. Two major terminal effectors in the Hippo signaling pathway are Yes-associated protein (YAP) and its homolog transcriptional coactivator with PDZ-binding motif (TAZ). The latest studies have reported the role of YAP and TAZ in different life stages, such as in fetal, neonatal, and adult hearts. Their regulation might involve several mechanisms and effectors. One of the possible coregulators is exercise. Exercise plays a role in cardiomyocyte hypertrophic changes during different stages of life, including in aged hearts. YAP/TAZ signaling pathway has a role in physiological cardiac hypertrophy induced by exercise and is associated with cardiac remodelling. Thus, it can be believed that exercise has roles in activating the signaling pathway of YAP and TAZ in aged cardiomyocytes. However, the studies regarding the roles of YAP and TAZ during cardiomyocyte aging are limited. The primary purpose of this review is to explore the response of cardiovascular aging to exercise via signaling pathway of YAP and TAZ.

Aerobic Exercise During Advance Stage of Uncontrolled Arterial Hypertension

Aim

To evaluate the influence of physical training on myocardial function, oxidative stress, energy metabolism, and MAPKs and NF-κB signaling pathways in spontaneously hypertensive rats (SHR), at advanced stage of arterial hypertension, which precedes heart failure development.

Methods

We studied four experimental groups: normotensive Wistar rats (W, n = 27), trained W (W-EX, n = 31), SHR (n = 27), and exercised SHR (SHR-EX, n = 32). At 13 months old, the exercise groups underwent treadmill exercise 5 days a week for 4 months. In vitro myocardial function was analyzed in left ventricular (LV) papillary muscle preparations. Antioxidant enzyme activity and energy metabolism were assessed by spectrophotometry. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity was analyzed by lucigenin reduction and protein expression by Western blot. Statistical analyzes: ANOVA and Tukey or Kruskal–Wallis and Dunn tests.

Results

SHR-EX had a lower frequency of heart failure features than SHR. Myocardial function and antioxidant enzyme activity were better in SHR-EX than SHR. Lipid hydroperoxide concentration, and phosphorylated JNK and total IkB protein expression were higher in hypertensive than control groups. Malondialdehyde, NADPH oxidase activity, total JNK, phosphorylated p38, phosphorylated and total p65 NF-κB, and phosphorylated IkB did not differ between groups. Protein expression from total p38, and total and phosphorylated ERK were higher in SHR than W. Lactate dehydrogenase and phosphorylated ERK were lower and citrate synthase and β-hydroxyacyldehydrogenase were higher in SHR-EX than SHR.

Conclusion

Exercise improves physical capacity, myocardial function, and antioxidant enzyme activity; reduces the frequency of heart failure features and ERK phosphorylation; and normalizes energy metabolism in SHR.

Anti-Apoptotic Effects of Resistance Training and Tribulus Terrestris Consumption in the Heart Tissue of Rats Exposed to Stanozolol

Objective

Nowadays, the use of energetic substances has become a complex problem in sports, such that the role of anabolic-androgenic steroids is undeniable. This study aimed to investigate the antiapoptotic effect of resistance training and Tribulus terrestris in the heart tissue of rats exposed to stanozolol.

Materials and Methods

35 rats divided into 7 groups including (1) sham, (2) stanozolol-treated, (3) stanozolol+50 mg/kg Tribulus terrestris-treated, (4) stanozolol+100 mg/kg Tribulus terrestris-treated, (5) stanozolol+resistance training-treated, (6) stanozolol+resistance training+50 mg/kg Tribulus terrestris-treated, and (7) stanozolol+resistance training+100 mg/kg Tribulus terrestris-treated. During 8 weeks, groups 2-7 received 5 mg/kg stanozolol per day peritoneally; groups 5-7 performed resistance training for 3 sessions per week; and groups 3, 4, 6 and 7 received daily doses of Tribulus terrestris peritoneally.

Results

Stanozolol administration significantly increased the BAX, BCL-2, P53, and caspase 3 and BAX/BCL-2 ratio (P < .001). Resistance training, 100 mg/kg Tribulus terrestris administration, 50 mg/kg Tribulus terrestris administration, resistance training+100 mg/kg Tribulus terrestris administration, and resistance training+50 mg/kg Tribulus terrestris administration significantly decreased BAX, BCL-2, P53, and caspase 3 levels and BAX/BCL-2 ratio (P < .001); however, stanozolol+resistance training+100 mg/kg Tribulus terrestris administration caused more decrease than stanozolol+resistance training+50 mg/kg Tribulus terrestris administration in BAX (P < .001).

Conclusion

Resistance training and Tribulus terrestris administration alone appear to have antiapoptotic effects; however, resistance training combined with Tribulus terrestris administration, especially at higher doses, have more desirable effects than resistance training or Tribulus terrestris administration alone on the apoptosis markers.

Voluntary exercise training attenuated the middle-aged maturity-induced cardiac apoptosis

AIMS

Voluntary exercise training has cardioprotective effects in humans, but the underlying mechanism is unknown. This research was done to estimate the effect of voluntary exercise training to attenuate middle-aged maturity-induced cardiac apoptosis.

MATERIALS AND METHODS

The study was designed to divide 64 male mice randomly into four groups, consisting of a 9-month sedentary pre-middle-aged group (9M), 15-month sedentary middle-aged group (15M), and two exercise groups using a voluntary wheel running respectively (9M+EX, 15M+EX). After 3 months, the condition of cardiac apoptosis in different groups was measured by HE dying, TUNEL and DAPI staining, and Western Blot analysis.

KEY FINDINGS

TUNEL-positive cells were increased in 15M group compared with 9M group, while decreased in 9M+EX and 15M+EX groups compared with their control groups respectively. Protein levels of AIF, Endo G, TNF-α, TNFR1, TRAF2, TRADD, Fas, FasL, FADD, activated caspase 8, 3, 9, Bax/Bcl2, Bak/BclxL, and tBid were decreased in 9M+EX and 15M+EX groups compared with their control groups respectively. The protein levels of pBad/Bad, 14-3-3, IGF1, IGFR1, pPI3K/PI3K, and pAKT/AKT were more activated in the 9M+EX and 15M+EX groups than those in their control groups respectively. Significant differences were found between 9M group and 15M group for the protein levels of TRAF2, FADD, Bax/Bcl2, tBid and pAKT/AKT.

SIGNIFICANCE

Voluntary exercise training as an important lifestyle modification may prevent cardiac widely dispersed apoptosis and enhance cardiac survival at middle-aged maturity.

Exercise training restores IGFIR survival signaling in d-galactose induced-aging rats to suppress cardiac apoptosis

Introduction

Insulin-like growth factor-I receptor (IGF1R) mediated survival signaling is a crucial mechanism for cellular endurance and a potential indicator of recuperation in deteriorating hearts.

Objective

This study evaluates the impact of long-term exercise training in enhancing cardiac survival mechanism in D-galactose-induced toxicity associated aging rats.

Methods

Forty-eight male SD-rats were segregated into 4 groups (n=9) and were named as control, exercise training groups, aging group and aging group with exercise training. Aging was induced by intraperitoneal (IP) D-galactose (150 mL/kg) injection for 8 weeks and for exercise training, the rats were left to swim in warm water for 60 min every day and 5 times/week. Western blotting of proteins from the left ventricles was performed to identify the modulations in the survival signaling. Tissue sections were analyzed to determine the extent of fibrosis and apoptosis.

Results

Western-blot analysis performed on the excised left ventricles (LV) showed that proteins of the cardiac survival pathway including IGF1R and Akt and the pro-survival Bcl-2 showed significant decrease in the aging group, whereas the levels were restored in the aging rats subjected to exercise training. In addition, aging groups showed increased interstitial space and collagen accumulation. Further, TUNEL assay showed higher number of apoptotic cells in the LV of aging group, which was correlated with increase in the proteins involved in FAS-FADD-dependent apoptosis. However, these aging associated effects were ameliorated upon exercise training in the D-galactose-induced aging rats that showed elevated IGF1R/Akt signaling.

Conclusion

The results suggest that IGFIR survival signaling cascadeis elevated in following long-term exercise training and thereby provide cardio-protective benefits in D-galactose induced aging rats.

Exercise Preconditioning Plays a Protective Role in Exhaustive Rats by Activating the PI3K-Akt Signaling Pathway

Objective

To investigate whether exercise preconditioning (EP) protects the rat heart from exhaustive exercise- (EE-) induced injury by inducing the PI3K-Akt signaling pathway.

Methods

84 male Sprague-Dawley rats were randomly divided into 6 groups (n = 14 rats per group): control group (Con), exhaustive exercise group (EE), exercise preconditioning group (EP), exercise preconditioning + exhaustive exercise group (EP + EE), LY294002 (PI3K inhibitor) + exercise preconditioning + exhaustive exercise group (LY + EP + EE), and LY294002 group (LY). The Con and LY did not exercise. The remaining groups were subjected to treadmill running. The structure of myocardial tissue and serum biomarkers of myocardial injury were observed. Hemodynamic parameters were recorded with a pressure-volume catheter. TUNEL assay was used to detect the apoptosis of cardiac myocytes, and the level of mitochondrial membrane permeability transforming pore (mPTP) in myocardium was evaluated using ELISA. Pathway and apoptosis-related proteins in myocardium were assessed using western blotting.

Results

Compared to the Con group, the EE group showed remarkable myocardial injury, such as cardiac dysfunction and myocardial apoptosis. Compared to the EE group, the injuries in the EP + EE group were improved. EP increased the PI3K-Akt signaling pathway and regulated Bcl-2 family to decrease the mPTP openness level. However, the cardioprotective effects of EP were attenuated when pretreated with the LY294002.

Conclusions

EP protected the heart from EE-induced injury, and it may improve the cardiac function and reduce the cardiomyocyte apoptosis by activating the PI3K-Akt signaling pathway.

Exercise training augments Sirt1-signaling and attenuates cardiac inflammation in D-galactose induced-aging rats

Exercise is known to be beneficial in controlling aging associated disorders however, the consequence of long-term exercise on cardiac health among aging population is not much clear. In this study the protective effect of exercise on aging associated cardiac disorders was determined using a D-galactose-induced aging model. Eight weeks old Sprague Dawley rats were given intraperitoneal injection of 150 mL/kg D-galactose. Swimming exercise was provided in warm water for 60 min/day for five days per week. Hematoxylin and eosin staining of cardiac tissue sections revealed cardiomyocyte disarrangements in the aging rat hearts but long-term exercise training showed improvements in the cardiac histology. Exercise training also enhanced the expression levels of proteins such as SIRT1, PGC-1α and AMPKα1 that are associated with energy homeostasis and further suppressed aging associated inflammatory cytokines. Our results show that long-term exercise training potentially enhances SIRT1 associated anti-aging signaling and provide cardio-protection against aging.

Melatonin differentially regulates pathological and physiological cardiac hypertrophy: Crucial role of circadian nuclear receptor RORα signaling

Exercise-induced physiological hypertrophy provides protection against cardiovascular disease, whereas disease-induced pathological hypertrophy leads to heart failure. Emerging evidence suggests pleiotropic roles of melatonin in cardiac disease; however, the effects of melatonin on physiological vs pathological cardiac hypertrophy remain unknown. Using swimming-induced physiological hypertrophy and pressure overload-induced pathological hypertrophy models, we found that melatonin treatment significantly improved pathological hypertrophic responses accompanied by alleviated oxidative stress in myocardium but did not affect physiological cardiac hypertrophy and oxidative stress levels. As an important mediator of melatonin, the retinoid-related orphan nuclear receptor-α (RORα) was significantly decreased in human and murine pathological hypertrophic cardiomyocytes, but not in swimming-induced physiological hypertrophic murine hearts. In vivo and in vitro loss-of-function experiments indicated that RORα deficiency significantly aggravated pathological cardiac hypertrophy, and notably weakened the anti-hypertrophic effects of melatonin. Mechanistically, RORα mediated the cardioprotection of melatonin in pathological hypertrophy mainly by transactivation of manganese-dependent superoxide dismutase (MnSOD) via binding to the RORα response element located in the promoter region of the MnSOD gene. Furthermore, MnSOD overexpression reversed the pro-hypertrophic effects of RORα deficiency, while MnSOD silencing abolished the anti-hypertrophic effects of RORα overexpression in pathological cardiac hypertrophy. Collectively, our findings provide the first evidence that melatonin exerts an anti-hypertrophic effect on pathological but not physiological cardiac hypertrophy via alleviating oxidative stress through transactivation of the antioxidant enzyme MnSOD in a RORα-dependent manner.

Antiapoptotic and mitochondrial biogenetic effects of exercise training on ovariectomized hypertensive rat hearts

This study was to investigate the effects of exercise training on antiapoptotic pathways and mitochondrial biogenesis in ovariectomized hypertensive rats. Histopathological analysis, TUNEL assay, and Western blotting were performed on the excised hearts from female spontaneously hypertensive rats (SHR), which were divided into a sham-operated sedentary hypertensive (SHR-S), a sedentary hypertensive ovariectomized (SHR-O), and hypertensive ovariectomized rats that underwent treadmill exercise training (SHR-OT; 60 min/day, 5 days/wk) for 8 wk, along with normotensive Wistar Kyoto rats (WKY). When compared with the WKY group, the SHR-S group exhibited decreased protein levels of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and mitochondrial OPA-1 (mitochondrial biogenesis) and decreased further in the SHR-O group. The protein levels of p-PI3K, p-Akt, Bcl-2, Bcl-xL (prosurvival pathways), and the protein levels of PGC-1α and mitochondrial OPA1 (mitochondrial biogenesis) were increased in the SHR-OT group, but estrogen receptor (ER)α and ERβ were not changed when compared with the SHR-O group. The protein levels of t-Bid, Bad, Bax, cytosolic cytochrome c, activated caspase 9, and activated caspase 3 (mitochondria-dependent apoptotic pathways), as well as Fas ligand, TNF-α, Fas receptors, Fas-associated death domain, activated caspase 8 (Fas receptor-dependent apoptotic pathways) were decreased in the SHR-OT group, when compared with the SHR-O group. Exercise training protection on the coexistence of hypertension and ovariectomy-induced cardiac mitochondria-dependent and Fas receptor-dependent apoptotic pathways by enhancing the Bcl2-related and mitochondrial biogenetic prosurvival pathways might provide a new therapeutic effect on cardiac protection in oophorectomized early postmenopausal hypertensive women. NEW & NOTEWORTHY Widely dispersed cardiac apoptosis was found in the coexistence of hypertension and ovariectomy. Exercise training on a treadmill could prevent ovariectomized hypertension-induced widely dispersed cardiac apoptosis via mitochondria-dependent apoptotic pathway (t-Bid, Bad, Bax, cytosolic cytochrome c, activated caspase 9, and activated caspase 3) and Fas receptor-dependent apoptotic pathway (Fas ligand, tumor necrosis factor-α, Fas receptors, Fas-associated death domain, activated caspase 8, and activated caspase 3) through enhancing the Bcl2-related (p-PI3K, p-Akt, Bcl-2, Bcl-xL) and mitochondrial biogenetic (PGC-1α and mitochondrial optic atrophy 1) prosurvival pathways.

GRK5 - A Functional Bridge Between Cardiovascular and Neurodegenerative Disorders

Complex aging-triggered disorders are multifactorial programs that comprise a myriad of alterations in interconnected protein networks over a broad range of tissues. It is evident that rather than being randomly organized events, pathophysiologies that possess a strong aging component such as cardiovascular diseases (hypertensions, atherosclerosis, and vascular stiffening) and neurodegenerative conditions (dementia, Alzheimer's disease, mild cognitive impairment, Parkinson's disease), in essence represent a subtly modified version of the intricate molecular programs already in place for normal aging. To control such multidimensional activities there are layers of trophic protein control across these networks mediated by so-called "keystone" proteins. We propose that these "keystones" coordinate and interconnect multiple signaling pathways to control whole somatic activities such as aging-related disease etiology. Given its ability to control multiple receptor sensitivities and its broad protein-protein interactomic nature, we propose that G protein coupled receptor kinase 5 (GRK5) represents one of these key network controllers. Considerable data has emerged, suggesting that GRK5 acts as a bridging factor, allowing signaling regulation in pathophysiological settings to control the connectivity between both the cardiovascular and neurophysiological complications of aging.

Fibrotic and apoptotic markers alteration in ovariectomised rats: addition of swimming training preserves lung architecture

CONTEXT

The important role of exercise in pulmonary function during menopause is not well known. Oestrogen deficiency in ageing female mice is accompanied by increase in apoptotic markers such as caspase3 in the lung.

OBJECTIVE

The present study was designed to investigate whether swimming training will ameliorate fibrosis and apoptosis resolution in the ovariectomy-induced lung injury rats.

MATERIAL AND METHOD

Thirty female rats were assigned to three groups (n = 10 in each group): sham; rats underwent bilateral laparotomy without ovariectomy, OVX; rats underwent bilateral ovariectomy, OVX.Exe; ovariectomised rats that underwent swimming training for eight weeks. At the end of eight weeks, the lungs were harvested and protein expressions in whole lung tissues were analysed by western blotting technique.

RESULT

Analysis of proteins expression in the lung showed significant differences between exercise and ovariectomised group (p < .05).

CONCLUSION

The present study indicates strong potential of exercise in experimental oestrogen deficiency-induced lung damage.

Cardiovascular Benefits of Exercise Training in Postmenopausal Hypertension

Exercise training is often considered the cornerstone of nonpharmacological therapy for postmenopausal hypertension while aerobic exercise is the mainstay of life style modification for antihypertension. Moderate-intensity aerobic exercise is well tolerated on most days of the week by most people with postmenopausal hypertension and is not suspected to detract from exercise adherence. That being said, moderate aerobic exercise may be superior for eliciting cardiovascular benefits in hypertensive postmenopausal women and resistance exercise may offer desirable benefits. The beneficial outcomes of exercise training for hypertensive postmenopausal women include improvements in blood pressure, autonomic tone, baroreflex sensitivity, oxidative stress, nitric oxide (NO), bioavailability, and lipid profiles, as well as cardiovascular function and cardiorespiratory fitness. This partly explains the fact that exercise training programs have a positive effect for cardiovascular disease in hypertensive postmenopausal women. This review is to collect and present the literature of exercise training in postmenopausal hypertension. Our review may provide the current understanding of beneficial effects and mechanisms of exercise intervention for prevention and treatment of stage 1 to 2 hypertensive postmenopausal women.

Physical Exercise and Regulation of Intracellular Calcium in Cardiomyocytes of Hypertensive Rats

BACKGROUND

Regulation of intracellular calcium (Ca2+) in cardiomyocytes is altered by hypertension; and aerobic exercise brings benefits to hypertensive individuals.

OBJECTIVE

To verify the effects of aerobic exercise training on contractility and intracellular calcium (Ca2+) transients of cardiomyocytes and on the expression of microRNA 214 (miR-214) in the left ventricle of spontaneously hypertensive rats (SHR).

METHODS

SHR and normotensive Wistar rats of 16 weeks were divided into 4 groups -sedentary hypertensive (SH); trained hypertensive (TH); sedentary normotensive (SN); and trained normotensive (TN). Animals of the TH and TN groups were subjected to treadmill running program, 5 days/week, 1 hour/day at 60-70% of maximum running velocity for 8 weeks. We adopted a p ≤ 0.05 as significance level for all comparisons.

RESULTS

Exercise training reduced systolic arterial pressure in hypertensive rats. In normotensive rats, exercise training reduced the time to 50% cell relaxation and the time to peak contraction and increased the time to 50% decay of the intracellular Ca2+ transients. In SHR, exercise increased the amplitude and reduced the time to 50% decay of Ca2+ transients. Exercise training increased the expression of miR-214 in hypertensive rats only.

CONCLUSION

The aerobic training applied in this study increased the availability of intracellular Ca2+ and accelerated the sequestration of these ions in left ventricular myocytes of hypertensive rats, despite increased expression of miR-214 and maintenance of cell contractility.

Exercise intervention attenuates hyperhomocysteinemia-induced aortic endothelial oxidative injury by regulating SIRT1 through mitigating NADPH oxidase/LOX-1 signaling

Coronary artery disease (CAD) is a critical cardiovascular disease and a cause of high morbidity and mortality in this world. Hyperhomocysteinemia (HHcy) has been suggested as a risk factor for CAD. In addition, SIRT1 (sirtuin 1) has been reported to play a protective role in a variety of diseases, especially in the cardiovascular system. The main purpose of this study was to investigate the effects of exercise training on apoptosis and inflammation in HHcy animals. We also tested whether exercise protected against Hhcy-induced dysfunction of endothelium through modulation of SIRT1. C57BL mice (8 in each group) were fed with or without 1% L-methionine (w/w) in water for 4 months to induce HHcy. We found that Hhcy repressed SIRT1 and AMPK expression and increased NADPH oxidase activity. Plasma MDA, endothelium LOX-1 and p-p38 were up-regulated by Hhcy induction. NF-κB and it downstream molecules were activated under Hhcy situation, thereby promoting pro-inflammatory responses. Moreover, we also reported that Hhcy caused endothelium apoptosis involving Akt inhibition and mitochondria-dependent apoptotic pathways. Exercise training significantly protected against endothelium from Hhcy caused oxidative injuries. In addition, EX527 (SIRT1 inhibitor) reduced the therapeutic effects by exercise. Our results had indicated that exercise training prevent the development of atherosclerosis through SIRT1 activation and oxidative stress inhibition under Hhcy situation.

Swim training attenuates the adverse remodeling of LV structural and mechanical properties in the early compensated phase of hypertension

AIM

Investigate to what extent low-intensity swim training for six weeks counterbalances the adverse remodeling due to the advance of pathological hypertrophy in the left ventricle (LV) structural and mechanical properties in the early compensated phase of hypertension in male SHR.

MAIN METHODS

Four-month-old male SHR and Wistar rats were randomly divided into Sed (sedentary) and Ex (exercised) groups. The exercised rats were submitted to a swimming protocol (1h/day, 5times/week, no additional load) for six weeks. LV tissue and isolated myocytes were used to assess structural and mechanical properties. Myocytes were stimulted at frequencies (F) of 1 and 3Hz at 37°C.

KEY FINDINGS

Exercised SHR showed improvement in cardiovascular parameters compared to sedentary SHR (mean arterial pressure: 13.22%; resting HR: 14.28.%). About structural and mechanical properties, swim training induced a decrease in LV myocyte thickness (10.85%), number of inflammatory cells (21.24%); collagen type III (74.23%) and type I (85.6%) fiber areas; amplitude of single myocyte shortening (47% to F1 and 28.46% to F3), timecourses of shortening (16.5% to F1 and 7.55% to F3) and relaxation (15.31% to F3) compared to sedentary SHR.

SIGNIFICANCE

Six weeks of swim training attenuates the adverse remodeling of LV structural and mechanical properties in the early compensated phase of hypertension in male SHR.

Therapeutic effect of mesenchymal stem cells on experimentally induced hypertensive cardiomyopathy in adult albino rats

Hypertensive heart diseases affect millions of people worldwide. We aimed to investigate the hypertensive left ventricular histological changes and assess the effectiveness of bone marrow derived mesenchymal stem cells (MSCs) therapy in the treatment of hypertensive cardiomyopathy. Adult male albino rats were assigned into two groups: group I (control), group II (Experimental) subdivided into subgroup IIa (hypertensive) and subgroup IIb (stem cell therapy). Left ventricles (LVs) were processed for light and electron microscope. Mallory's trichrome and immunostaining for caspase-3 and desmin were carried out. Hypertension caused left ventricular histological and immunohistochemical changes that had been effectively improved by MSCs therapy.

The Coexistence of Hypertension and Ovariectomy Additively Increases Cardiac Apoptosis

To investigate whether the coexistence of hypertension and ovariectomy will increase cardiac Fas receptor and mitochondrial-dependent apoptotic pathways, histopathological analysis, the TUNEL assay and Western blotting were performed on the excised hearts from three groups of female spontaneously hypertensive rats (SHR), which were divided into a sham-operated group (SHR-Sham), bilaterally ovariectomized group (SHR-OVX) and normotensive Wistar Kyoto rats (WKY). Compared with the WKY group, the SHR-Sham group exhibited decreased protein levels of ERα, ERβ, p-Akt/Akt, Bcl-2, Bcl-xL and p-Bad and decreased further in the SHR-OVX group, as well as protein levels of t-Bid, Bak, Bad, Bax, cytochrome c, activated caspase-9 and activated caspase-3 (mitochondria-dependent apoptosis) increased in the SHR-Sham group and increased further in the SHR-OVX group. Compared with the WKY group, protein levels of Fas ligand, TNF-α, Fas death receptors, TNFR1, FADD and activated caspase-8 (Fas receptor-dependent apoptosis) increased in the SHR-Sham group, but did not increase in the SHR-OVX group, except Fas ligand and TNF-α. The coexistence of hypertension and ovariectomy attenuated the estrogen receptor survival pathway and appeared to additively increase the cardiac mitochondria-dependent, but not the Fas receptor-dependent apoptosis pathway, which might provide one possible mechanism for the development of cardiac abnormalities in hypertensive postmenopausal women.

Exercise Training Attenuates Right Ventricular Remodeling in Rats with Pulmonary Arterial Stenosis

Introduction: Pulmonary arterial stenosis (PAS) is a congenital defect that causes outflow tract obstruction of the right ventricle (RV). Currently, negative issues are reported in the PAS management: not all patients may be eligible to surgeries; there is often the need for another surgery during passage to adulthood; patients with mild stenosis may have later cardiac adverse repercussions. Thus, the search for approaches to counteract the long-term PAS effects showed to be a current target. At the study herein, we evaluated the cardioprotective role of exercise training in rats submitted to PAS for 9 weeks.

Methods and Results: Exercise resulted in improved physical fitness and systolic RV function. Exercise also blunted concentric cavity changes, diastolic dysfunction, and fibrosis induced by PAS. Exercise additional benefits were also reported in a pro-survival signal, in which there were increased Akt₁ activity and normalized myocardial apoptosis. These findings were accompanied by microRNA-1 downregulation and microRNA-21 upregulation. Moreover, exercise was associated with a higher myocardial abundance of the sarcomeric protein α-MHC and proteins that modulate calcium handling—ryanodine receptor and Serca 2, supporting the potential role of exercise in improving myocardial performance.

Conclusion: Our results represent the first demonstration that exercise can attenuate the RV remodeling in an experimental PAS. The cardioprotective effects were associated with positive modulation of RV function, survival signaling pathway, apoptosis, and proteins involved in the regulation of myocardial contractility.

Light-intensity and high-intensity interval training improve cardiometabolic health in rats

Physical activity has the potential to reduce cardiometabolic risk factors but evaluation of different intensities of physical activity and the mechanisms behind their health effects still need to be fully established. This study examined the effects of sedentary behaviour, light-intensity training, and high-intensity interval training on biometric indices, glucose and lipid metabolism, inflammatory and oxidative stress markers, and vascular and cardiac function in adult rats. Rats (12 weeks old) were randomly assigned to 1 of 4 groups: control (CTL; no exercise), sedentary (SED; no exercise and housed in small cages to reduce activity), light-intensity trained (LIT; four 30-min exercise bouts/day at 8 m/min separated by 2-h rest period, 5 days/week), and high-intensity interval trained (HIIT, four 2.5-min work bouts/day at 50 m/min separated by 3-min rest periods, 5 days/week). After 12 weeks of intervention, SED had greater visceral fat accumulation (p < 0.01) and slower cardiac conduction (p = 0.04) compared with the CTL group. LIT and HIIT demonstrated beneficial changes in body weight, visceral and epididymal fat weight, glucose regulation, low-density lipoprotein cholesterol, total cholesterol, and mesenteric vessel contractile response compared with the CTL group (p < 0.05). LIT had significant improvements in insulin sensitivity and cardiac conduction compared with the CTL and SED groups whilst HIIT had significant improvements in systolic blood pressure and endothelium-independent vasodilation to aorta and mesenteric artery compared with the CTL group (p < 0.05). LIT and HIIT induce health benefits by improving traditional cardiometabolic risk factors. LIT improves cardiac health while HIIT promotes improvements in vascular health.

Deep sea minerals prolong life span of streptozotocin-induced diabetic rats by compensatory augmentation of the IGF-I-survival signaling and inhibition of apoptosis

Consumption of deep sea minerals (DSM), such as magnesium, calcium, and potassium, is known to reduce hypercholesterolemia-induced myocardial hypertrophy and cardiac-apoptosis and provide protection against cardiovascular diseases. Heart diseases develop as a lethal complication among diabetic patients usually due to hyperglycemia-induced cardiac-apoptosis that causes severe cardiac-damages, heart failure, and reduced life expectancy. In this study, we investigated the potential of DSM and its related cardio-protection to increase the life expectancy in diabetic rats. In this study, a heart failure rat model was developed by using streptozotocin (65 mg kg(-1) ) IP injection. Different doses of DSM-1× (37 mg kg(-1) day(-1) ), 2× (74 mg kg(-1) day(-1) ) and 3× (111 mg kg(-1) day(-1) ), were administered to the rats through gavages for 4 weeks. The positive effects of DSM on the survival rate of diabetes rats were determined with respect to the corresponding effects of MgSO4 . Further, to understand the mechanism by which DSM enhances the survival of diabetic rats, their potential to regulate cardiac-apoptosis and control cardiac-dysfunction were examined. Echocardiogram, tissue staining, TUNEL assay, and Western blotting assay were used to investigate modulations in the myocardial contractile function and related signaling protein expression. The results showed that DSM regulate apoptosis and complement the cardiomyocyte proliferation by enhancing survival mechanisms. Moreover DSM significantly reduced the mortality rate and enhanced the survival rate of diabetic rats. Experimental results show that DSM administration can be an effective strategy to improve the life expectancy of diabetic subjects by improving cardiac-cell proliferation and by controlling cardiac-apoptosis and associated cardiac-dysfunction. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 769-781, 2016.

The Role of Exercise in Cardiac Aging: From Physiology to Molecular Mechanisms

Aging induces structural and functional changes in the heart that are associated with increased risk of cardiovascular disease and impaired functional capacity in the elderly. Exercise is a diagnostic and therapeutic tool, with the potential to provide insights into clinical diagnosis and prognosis, as well as the molecular mechanisms by which aging influences cardiac physiology and function. In this review, we first provide an overview of how aging impacts the cardiac response to exercise, and the implications this has for functional capacity in older adults. We then review the underlying molecular mechanisms by which cardiac aging contributes to exercise intolerance, and conversely how exercise training can potentially modulate aging phenotypes in the heart. Finally, we highlight the potential use of these exercise models to complement models of disease in efforts to uncover new therapeutic targets to prevent or treat heart disease in the aging population.

Antiapoptotic effect of exercise training on ovariectomized rat hearts

The purpose of this study was to evaluate the effects of exercise training on cardiac Fas receptor-dependent and mitochondria-dependent apoptotic pathways in ovariectomized rats. Histopathological analysis, TUNEL assay, and Western blotting were performed on the excised hearts from three groups of Sprague-Dawley rats, which were divided into a sham-operated group, a bilaterally ovariectomized group (OVX), and a bilaterally ovariectomized group that underwent treadmill running exercise for 60 min/day, 5 sessions/wk, for 10 wk (OVX-EX). The abnormal myocardial architecture, cardiac trichome-stained fibrosis and cardiac TUNEL-positive apoptotic cells in ovariectomized rats improved after exercise training. The protein levels of tumor necrosis factor-α, tumor necrosis factor receptor 1, Fas ligand, Fas receptors, Fas-associated death domain, activated caspase-8 and activated caspase-3 (Fas receptor-dependent apoptotic pathways), as well as t-Bid, Bad, Bak, Bax, cytosolic cytochrome c, activated caspase-9, and activated caspase-3 (mitochondria-dependent apoptotic pathways) were decreased in the OVX-EX group compared with the OVX group. Exercise training suppressed ovariectomy-induced cardiac Fas receptor-dependent and mitochondria-dependent apoptotic pathways in ovariectomized rat models. These findings might indicate a new therapeutic effect for exercise training to prevent cardiac apoptosis in menopausal or bilaterally oophorectomized women.

Therapeutic effects of Dioscorea on post-menopause-induced cardiac apoptosis in rats

OBJECTIVE

To evaluate the effects of Dioscorea on bilateral ovariectomies-induced cardiac Fasdependent and mitochondria-dependent apoptotic pathways.

METHODS

Forty-eight female Wistar rats at 6-7 months of age were equally divided into a sham-operated group, and a bilateral ovariectomized (OVX) group for 2 months, and the rats in the OVX group were further fed with 0, 250 or 750 mL/kg Dioscorea spp. daily in the 2nd month. The excised hearts were measured by positive terminal deoxynucleotidyltransferase UTP nick end labeling (TUNEL) assays, western blotting and reverse transcription-polymerase chain reaction.

RESULTS

Dioscorea spp. decreased OVX-induced cardiac TUNEL-positive apoptotic cells; decreased OVX-induced TNF-alpha, Fas ligand, Fas death receptors, Fas-associated death domain, activated caspase-8, and -3 (Fas pathways); decreased OVX-induced Bad, Bax, Bax-to-Bcl2 ratio, activated caspase-9, and -3 (mitochondria pathway).

CONCLUSIONS

Dioscorea spp. prevented ovariectomy-induced cardiac Fas-dependent and mitochondriadependent apoptotic pathways in rat models. The fifi ndings may provide possible therapeutic effects of dioscorea for potentially preventing cardiac apoptosis after ovariectomy or post-menopause.

Anti-apoptotic effect of San Huang Shel Shin Tang cyclodextrin complex (SHSSTc) on CCl4 -induced hepatotoxicity in rats

The metabolic loading is heavier in liver especially when injured or inflammation. San Huang Shel Shin Tang (SHSST) was an old traditional herbal decoction, which composed with Rheum officinale Baill, Scutellaria baicalnsis Geprgi and Coptis chinensis Franch (1:1:2 in weight), can provide a liver protection effects. We used a beta-cyclodextrin (β-CD) drug modification method in reduce of the necessary dose of the SHSST. As the results, the FAS-FADD expressions leaded apoptosis in CCl4 intraperitoneal (IP) injection induced acute liver injury in rats. Silymarin, baicalein, SHSST, and SHSST β-CD complex (SHSSTc) pretreatments protected liver through the decreasing of the expressions of FAS-FADD and downstream caspase-3 and caspase-8. Particularly, SHSSTc (30 mg/kg day) treatment enhanced cell survival pathway activation through the PI3K, Akt and Bad phosphorylation. Compared with SHSST as well as silymarin and baicalein, SHSSTc provided a magnificent liver protection effect, especially in survival pathway activation/TUNEL-apoptotic cell reduction/serum cholesterol level suppression. All these data suggested that β-CD complex modified the SHSST and promoted the bioavailability and liver protection effects. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 663-670, 2016.

San Huang Shel Shin Tang beta-cyclodextrin complex augmented the hepatoprotective effects against carbon tetrachloride-induced acute hepatotoxicity in rats

BACKGROUND

San Huang Shel Shin Tang (SHSST) is a traditional herbal decoction used as a hepato-protective agent and is composed of Rheum officinale Baill, Scutellaria baicalnsis Geprgi and Coptis chinensis Franch (2:1:1 w/w). Beta-cyclodextrin (β-CD) modification may potentially increase the solubility and spectral properties of SHSST.

METHODS

In this research, the hepato-protective effects of unmodified SHSST, β-CD modified SHSST complex (SHSSTc) and silymarin were evaluated in carbon tetrachloride (CCl4) induced acute hepatotoxicity in rats.

RESULTS

SHHSTc (40 mg/kg/day) and silymarin (100 mg/kg/day) both decreased the CCl4-induced cirrhosis pathway-related transforming growth factor beta (TGF-β) and apoptosis pathway-related caspase-8 protein expressions, but SHSST (40 mg/kg/day) did not reduce TGF-β and caspase-8 significantly . Moreover, SHHSTc (40 mg/kg/day) enhanced the activation of insulin-like growth factor 1 receptor (IGF1R) mediated survival pathway than the silymarin (100 mg/kg/day) to protect the liver from damage induced by CCl4.

CONCLUSIONS

β-CD modification promotes hepato-protective effects of SHSST and reduces the required-dosage of the SHSST.

The expanding GRK interactome: Implications in cardiovascular disease and potential for therapeutic development

Heart failure (HF) is a global epidemic with the highest degree of mortality and morbidity of any disease presently studied. G protein-coupled receptors (GPCRs) are prominent regulators of cardiovascular function. Activated GPCRs are "turned off" by GPCR kinases (GRKs) in a process known as "desensitization". GRKs 2 and 5 are highly expressed in the heart, and known to be upregulated in HF. Over the last 20 years, both GRK2 and GRK5 have been demonstrated to be critical mediators of the molecular alterations that occur in the failing heart. In the present review, we will highlight recent findings that further characterize "non-canonical" GRK signaling observed in HF. Further, we will also present potential therapeutic strategies (i.e. small molecule inhibition, microRNAs, gene therapy) that may have potential in combating the deleterious effects of GRKs in HF.

Anti-Apoptotic and Pro-Survival Effect of Alpinate Oxyphyllae Fructus (AOF) in a d-Galactose-Induced Aging Heart

Aging, a natural biological/physiological phenomenon, is accelerated by reactive oxygen species (ROS) accumulation and identified by a progressive decrease in physiological function. Several studies have shown a positive relationship between aging and chronic heart failure (HF). Cardiac apoptosis was found in age-related diseases. We used a traditional Chinese medicine, Alpinate Oxyphyllae Fructus (AOF), to evaluate its effect on cardiac anti-apoptosis and pro-survival. Male eight-week-old Sprague–Dawley (SD) rats were segregated into five groups: normal control group (NC), d-Galactose-Induced aging group (Aging), and AOF of 50 (AL (AOF low)), 100 (AM (AOF medium)), 150 (AH (AOF high)) mg/kg/day. After eight weeks, hearts were measured by an Hematoxylin–Eosin (H&E) stain, Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-assays and Western blotting. The experimental results show that the cardiomyocyte apoptotic pathway protein expression increased in the d-Galactose-Induced aging groups, with dose-dependent inhibition in the AOF treatment group (AL, AM, and AH). Moreover, the expression of the pro-survival p-Akt (protein kinase B (Akt)), Bcl-2 (B-cell lymphoma 2), anti-apoptotic protein (Bcl-xL) protein decreased significantly in the d-Galactose-induced aging group, with increased performance in the AOF treatment group with levels of p-IGFIR and p-PI3K (Phosphatidylinositol-3′ kinase (PI3K)) to increase by dosage and compensatory performance. On the other hand, the protein of the Sirtuin 1 (SIRT1) pathway expression decreased in the aging groups and showed improvement in the AOF treatment group. Our results suggest that AOF strongly works against ROS-induced aging heart problems.

"Canonical and non-canonical actions of GRK5 in the heart"

As the average world-wide lifespan continues to increase, heart failure (HF) has dramatically increased in incidence leading to the highest degree of mortality and morbidity of any disease presently studied. G protein-coupled receptors (GPCRs) play a prominent role in regulation of cardiovascular function. GPCRs are effectively "turned off" by GPCR kinases (GRKs) in a process known as "desensitization". GRKs 2 and 5 are highly expressed in the heart, and known to be upregulated in HF. Over the last 20years, the role of GRK2 in HF has been widely studied. However, until recently, the role of GRK5 in cardiac pathophysiology had yet to be elucidated. In the present review, we will focus on GRK5's role in the myocardium in normal physiology, and its apparent critical role in the progression of HF. Further, we will also present potential therapeutic strategies (i.e. small molecule inhibition, gene therapy) that may have potential in combating the deleterious effects of GRK5 in HF.

Heat-killed Lactobacillus Reuteri GMNL-263 Prevents Epididymal Fat Accumulation and Cardiac Injury in High-Calorie Diet-Fed Rats

High-calorie diet-induced obesity leads to cardiomyocyte dysfunction and apoptosis. Impaired regulation of epididymal fat content in obese patients has been known to increase the risk of cardiac injury. In our study, a lactic acid bacteria, Lactobacillus reuteri GMNL-263, was evaluated for its potential to reduce body weight and body fat ratio and to prevent heart injury in rats with high-fat diet-induced obesity. Lactic acid bacteria supplementation restored the cardiac function and decreased the physiological changes in the heart of the obese rats. In addition, the Fas/Fas-associated protein pathway-induced caspase 3/e Poly polymerase mediated apoptosis in the cardiomyocytes of the obese rats was reversed in the Lr263-treated rats. These results reveal that fed with Lr-263 reduces body fat ratio, inhibits caspase 3-mediated apoptosis and restores cardiac function in obese rats through recovery of ejection fraction and fractional shortening. Our results indicated that the administration of Lr263 lactic acid bacteria can significantly down-regulate body fat and prevent cardiomyocyte injury in obese rats.

Multi-Strain Probiotics Inhibit Cardiac Myopathies and Autophagy to Prevent Heart Injury in High-Fat Diet-Fed Rats

High-fat diets induce obesity, leading to cardiomyocyte fibrosis and autophagy imbalance. In addition, no previous studies have indicated that probiotics have potential health effects associated with cardiac fibrosis and autophagy in obese rats. This study investigates the effects of probiotics on high-fat (HF) diet-induced obesity and cardiac fibrosis and autophagy in rat hearts. Eight-week-old male Wistar rats were separated randomly into five equally sized experimental groups: Normal diet (control) and high-fat (HF) diet groups and groups fed a high-fat diet supplemented with low (HL), medium (HM) or high (HH) doses of multi-strain probiotic powders. These experiments were designed for an 8-week trial period. The myocardial architecture of the left ventricle was evaluated using Masson's trichrome staining and immunohistochemistry staining. Key probiotics-related pathway molecules were analyzed using western blotting. Abnormal myocardial architecture and enlarged interstitial spaces were observed in HF hearts. These interstitial spaces were significantly decreased in groups provided with multi-strain probiotics compared with HF hearts. Western blot analysis demonstrated that key components of the TGF/MMP2/MMP9 fibrosis pathways and ERK5/uPA/ANP cardiac hypertrophy pathways were significantly suppressed in probiotic groups compared to the HF group. Autophagy balance is very important in cardiomyocytes. In this study, we observed that the beclin-1/LC3B/Atg7 autophagy pathway in HF was increased after probiotic supplementation was significantly decreased. Together, these results suggest that oral administration of probiotics may attenuate cardiomyocyte fibrosis and cardiac hypertrophy and the autophagy-signaling pathway in obese rats.

Regulation of cardiac microRNAs induced by aerobic exercise training during heart failure

Exercise training (ET) has beneficial effects on the myocardium in heart failure (HF) patients and in animal models of induced cardiac hypertrophy and failure. We hypothesized that if microRNAs (miRNAs) respond to changes following cardiac stress, then myocardial profiling of these miRNAs may reveal cardio-protective mechanisms of aerobic ET in HF. We used ascending aortic stenosis (AS) inducing HF in Wistar rats. Controls were sham-operated animals. At 18 wk after surgery, rats with cardiac dysfunction were randomized to 10 wk of aerobic ET (HF-ET) or to a heart failure sedentary group (HF-S). ET attenuated cardiac remodeling as well as clinical and pathological signs of HF with maintenance of systolic and diastolic function when compared with that of the HF-S. Global miRNA expression profiling of the cardiac tissue revealed 53 miRNAs exclusively dysregulated in animals in the HF-ET, but only 11 miRNAs were exclusively dysregulated in the HF-S. Out of 23 miRNAs that were differentially regulated in both groups, 17 miRNAs exhibited particularly high increases in expression, including miR-598, miR-429, miR-224, miR-425, and miR-221. From the initial set of deregulated miRNAs, 14 miRNAs with validated targets expressed in cardiac tissue that respond robustly to ET in HF were used to construct miRNA-mRNA regulatory networks that revealed a set of 203 miRNA-target genes involved in programmed cell death, TGF-β signaling, cellular metabolic processes, cytokine signaling, and cell morphogenesis. Our findings reveal that ET attenuates cardiac abnormalities during HF by regulating cardiac miRNAs with a potential role in cardio-protective mechanisms through multiple effects on gene expression.

Protective effects of electroacupuncture at LR3 on cardiac hypertrophy and apoptosis in hypertensive rats

OBJECTIVES

To investigate the effect of electroacupuncture (EA) at LR3 on blood pressure (BP) and cardiovascular remodelling and hypertrophy in male spontaneously hypertensive rats (SHRs).

METHODS

Healthy Wistar-Kyoto rats were used as normotensive controls (control group, n=9). SHRs either remained untreated (SHR group, n=9) or received EA treatment at LR3 (SHR+LR3 group, n=9) or a nearby non-acupuncture point (SHR+sham group, n=9) for 3 weeks. BP was measured on day 3 and day 19. Samples of left ventricle were stained with haematoxylin and eosin or subjected to terminal deoxynucleotidyl transferase dUTP (deoxyuridine triphosphate) nick end labelling (TUNEL) to assess histology and apoptosis, respectively (n=3 per group). Western blotting was used to determine the relative expression of antioxidants and molecular markers of detoxification capacity, cardiac hypertrophy, and apoptosis (n=5 per group).

RESULTS

By day 3, the systolic BP, mean BP, and diastolic BP in the untreated SHRs increased from 169.5±14, 131.6±14, and 112.2±15 mm Hg (at baseline) to 179.6±1, 137.6±4, and 118.7±5 mm Hg, respectively (p<0.001 vs control group). BP in the SHR+LR3 rats was approximately 15 mm Hg lower than the SHR and SHR+sham groups (p<0.05). SHRs also exhibited cardiac hypertrophy (evident from histological and Western blot analyses). However, SHR+LR3 rats showed significant reductions in markers of cardiac hypertrophy and apoptosis, as well as elevated expression of antioxidant enzymes including superoxide dismutase-1 (SOD1).

CONCLUSIONS

EA at LR3 reduced BP and had positive effects on markers of cardiac apoptosis and hypertrophy in a rat model of hypertension. Thus, EA is a potentially promising intervention to treat cardiovascular remodelling secondary to hypertension.

Differential Role of G Protein-Coupled Receptor Kinase 5 in Physiological Versus Pathological Cardiac Hypertrophy

RATIONALE

G protein-coupled receptor kinases (GRKs) are dynamic regulators of cellular signaling. GRK5 is highly expressed within myocardium and is upregulated in heart failure. Although GRK5 is a critical regulator of cardiac G protein-coupled receptor signaling, recent data has uncovered noncanonical activity of GRK5 within nuclei that plays a key role in pathological hypertrophy. Targeted cardiac elevation of GRK5 in mice leads to exaggerated hypertrophy and early heart failure after transverse aortic constriction (TAC) because of GRK5 nuclear accumulation.

OBJECTIVE

In this study, we investigated the role of GRK5 in physiological, swimming-induced hypertrophy (SIH).

METHODS AND RESULTS

Cardiac-specific GRK5 transgenic mice and nontransgenic littermate control mice were subjected to a 21-day high-intensity swim protocol (or no swim sham controls). SIH and specific molecular and genetic indices of physiological hypertrophy were assessed, including nuclear localization of GRK5, and compared with TAC. Unlike after TAC, swim-trained transgenic GRK5 and nontransgenic littermate control mice exhibited similar increases in cardiac growth. Mechanistically, SIH did not lead to GRK5 nuclear accumulation, which was confirmed in vitro as insulin-like growth factor-1, a known mediator of physiological hypertrophy, was unable to induce GRK5 nuclear translocation in myocytes. We found specific patterns of altered gene expression between TAC and SIH with GRK5 overexpression. Further, SIH in post-TAC transgenic GRK5 mice was able to preserve cardiac function.

CONCLUSIONS

These data suggest that although nuclear-localized GRK5 is a pathological mediator after stress, this noncanonical nuclear activity of GRK5 is not induced during physiological hypertrophy.

Long-term treadmill training ameliorates endothelium-dependent vasorelaxation mediated by insulin and insulin-like growth factor-1 in hypertension

Dysfunction of insulin and insulin-like growth factor-1 (IGF-1) is associated with the pathophysiology of hypertension. The influence of long-term exercise on vascular dysfunction caused by hypertension remains unclear. We investigated whether long-term treadmill training improved insulin- and IGF-1-mediated vasorelaxation in hypertensive rats. Eight-week-old male spontaneously hypertensive rats (SHR) were randomly divided into sedentary and exercise (SHR-EX) groups. The SHR-EX group was trained on a treadmill for 60 min/day, 5 days/wk, for 8 wk. Wistar-Kyoto rats (WKY) were used as the normal control group. After training, aortic insulin- and IGF-1-mediated vasorelaxation was evaluated in organ baths. Additionally, the roles of phosphatidylinositol 3-kinase (PI3K), nitric oxide synthase (NOS), and aortic protein expression were examined in the three groups. Compared with sedentary SHR and WKY groups, insulin- and IGF-1-mediated vasorelaxation was significantly enhanced to a nearly normal level in the SHR-EX group. After endothelial denudation, blunted and comparable vasorelaxation was found among the three groups. Pretreatment with selective PI3K and NOS inhibitors attenuated insulin- and IGF-1-mediated vasorelaxation, and no significant difference was found among the three groups after the pretreatment. The aortic protein levels of the insulin receptor (IR), IGF-1 receptor (IGF-1R), insulin receptor substrate-1 (IRS-1), and endothelial NOS (eNOS) were also significantly increased in the SHR-EX group compared with the other two groups. These results suggested that treadmill training elicited the amelioration of endothelium-dependent insulin/IGF-1-mediated vasorelaxation partly via the increased activation of PI3K and NOS, as well as the enhancement of protein levels of IR, IGF-1R, IRS-1, and eNOS, in hypertension.