Exercise ameliorates renal cell apoptosis in chronic kidney disease by intervening in the intrinsic and the extrinsic apoptotic pathways in a rat model

Benefits of high-intensity interval training compared to continuous training to reduce apoptotic markers in female rats with cisplatin nephrotoxicity - possible modulatory role of IL-11

Apoptotic signaling pathways are involved in acute kidney injury (AKI) induced by the antineoplastic drug cisplatin (Cis). Mechanical stress is known to increase interleukin (IL) -11, a pleiotropic cytokine with antiapoptotic and antinecrotic effects. We compared the impact of high-intensity interval training (HIIT) with low-intensity continuous training (LICT) and moderate-intensity continuous training (MICT) on renal levels of IL-11 and the expression of apoptotic markers in female rats with nephrotoxicity induced by Cis. For that, the animals were divided into five groups (n = 7): control and sedentary (C + S); Cis and sedentary (Cis + S); Cis and LICT (Cis + LICT); Cis and MICT (Cis + MICT) and Cis and HIIT (Cis + HIIT). At the end of 8 weeks of treadmill running, the rats received a single injection of Cis (5 mg/kg), and 7 days later they were euthanized. Serum and kidney samples were collected to assess the blood urea nitrogen (BUN), gene expression of TNF receptor 1 (TNFR1) and 2 (TNFR2), caspase-3, (p38) MAPK (MAPK14), p53, Bax, Bak, Bcl-2, and Bcl-xL, renal levels of IL-11, IL-8, and p53, and immunolocalization of cleaved caspase-3, Bax, Bcl-2, and (p38) MAPK in renal tissue. Our data indicate that all trained groups showed a significant intensity-dependent increase in renal levels of IL-11 associated with reduced local expression of proapoptotic and increased antiapoptotic markers, but these effects were more pronounced with HIIT. So, HIIT appears to provide superior renoprotection than traditional continuous training by modulating apoptotic signaling pathways, and this effect can be related to the increase in renal levels of IL-11.

The effect of two types of diet on apoptosis indexes, lipid profile and histopathological outcome in acute kidney injury during exercise

Background

Exercise and some pre-AKI diets have been shown to improve injury, apoptosis, and lipid profile. In this study, the effect of two different diets along with exercise training on acute kidney injury (AKI) was investigated. 

Materials and methods

Laboratory rats were randomly divided into four groups of control, standard diet + exercise, exercise + calorie restriction (CR) and exercise + time restriction (TR). Each group was divided into two subgroups of AKI and no AKI. The animals received endurance training and diet regimens before AKI. Fasting blood glucose, serum creatinine, Bcl-2-associated X protein (Bax), B-cell lymphoma 2 (Bcl2) and histopathological outcome of renal tissue as well as serum lipid profile of animals were assessed 24 h after AKI. 

Results

The percentage of changes in renal Bcl2 and Bax after AKI in the group with previous exercise was lower than the group without previous exercise (p < 0.01). After induction of AKI, serum lipid profile changed in non-exercised rats (p < 0.001). Also, after injury, fasting blood glucose levels increased in non-exercised rats (p < 0.05). After injury, the start of both CR and TR diets during exercise caused less change in Bcl2 and Bax of non-exercised rats compared to exercised rats (p < 0.001). CR diet along with exercise improved lipid profile, and also CR diet along exercise decreased fasting blood glucose levels (p < 0.001). Also, both the CR and TR diets during exercise caused fewer changes in histopathological outcome after AKI.

Conclusion

Exercise alone decreased changes in apoptotic and histopathological indexes, fasting blood glucose, as well as lipid profile of rats after AKI. Reduction of apoptosis and improvement of histopathological outcome after AKI appeared more when CR and TR diets were commenced during exercise. The reduction of lipid profile changes was more pronounced in the group that received CR diet during exercise.

Swimming Exercise Ameliorates Hypertension-Induced Kidney Dysfunction via Alleviating Renal Interstitial Fibrosis and Apoptosis

BACKGROUND

Hypertensive nephropathy is one of the major causes of ESRD. Exercise has been considered a nonpathological therapy for hypertension and its complications, yet mechanisms remain unclear. We sought to investigate whether periodic swimming could ameliorate hypertension-induced kidney dysfunction and its underlying mechanisms.

METHODS

Four-week male spontaneously hypertensive rats (SHRs) were randomly divided into the hypertension group (SHR, n = 8) and exercise group (SE, n = 8, 60 min swimming/day, 6 days per week, for 8 weeks). Wistar-Kyoto rats (WKY, n = 8) were served as a sedentary normotensive group. Bodyweight and blood pressure (BP) were recorded weekly. After 8-week sedentary or swimming exercise, lipids profile, BUN, and Cr were measured. The renal interstitial fibrosis was examined by the histopathological analysis using Masson's trichrome staining and hematoxylin and eosin staining. The kidney cell apoptosis was tested by TUNEL staining. The expressions of critical proteins responsible for the TGF-β1/Smad signaling of fibrosis, that is, TGF-β1, Smad2/3, and Smad7, as well as apoptosis related proteins, Bax and Bcl-2 in kidney cortex tissues were measured.

RESULTS

The 8-week swimming exercise reduced BP and bodyweight, lowered concentrations of BUN, and serum Cr, compared with SHR. Exercise remarkably inhibited hypertension-induced tubular degeneration, cellular cluster, and tubular cell swelling as well as glomerular degeneration in the kidney cortical tissues, attenuated renal interstitial fibrosis, and renal cell apoptosis. Moreover, expressions of TGF-β1, Smad2/3, and Bax were higher in the SHR than the WKY, which were significantly suppressed by the exercise. In contrast, hypertension-reduced expressions of Smad7 and Bcl-2 were enhanced by the swimming exercise. Strong correlations were found between kidney function indices, blood lipids, and key protein expressions.

CONCLUSION

Our results demonstrate beneficial effects of the periodic swimming on ameliorating hypertension-induced kidney dysfunction highlighting the potential of swimming exercise as a nonpathological therapy for early prevention of hypertension-caused kidney diseases.

Attenuated Renal and Hepatic Cells Apoptosis Following Swimming Exercise Supplemented with Garlic Extract in Old Rats

Background/Objective

One of the problems associated with aging is the development of apoptosis in different tissues. There is evidence that physical activity and herbal remedies can be useful. This study aimed to determine the effect of swimming training (SW) alone or combined with garlic extract on renal and hepatic cells apoptosis, as wellas on the liver and kidney function biomarkers in old rats.

Methods

A total of 35 old rats (aged 40–50 weeks) were randomly divided into 5 groups including control, saline (S), exercise training (ET), garlic (G) and exercise training+ garlic (ET.G) groups. Exercise was started for 5 min/day and then gradually extended to 60 min/day and the G and E+G groups received 1 mL/kg of this mixture by gavage. Twenty-four hours after completion of 8 weeks training, liver, kidney and blood samples were collected for histopathological examinations, liver and kidney functions, oxidative stress and apoptosis biomarkers.

Results

The tissue sections of the SW exercise, control and saline groups showed some mild histopathological changes in liver and kidney, while SW supplemented with garlic prevented these damages. The SW alone or supplemented with garlic significantly increased the Bcl-2 value and declined the BAX level in both liver and kidney (p<0.05). The activities of catalase (CAT) and superoxide dismutase (SOD) in the liver and kidney of the control and saline groups were lower than those in E, G and G+E groups, while a significant increase for malondialdehyde (MDA) value was found in the control and saline groups. Furthermore, the E+G significantly declined the activity of hepatic (ALT, AST and ALP) and renal damage (uric acid, urea and creatinine) biomarkers compared to the control and saline groups (p<0.05).

Discussion

Swimming exercise supplemented with garlic extract not only improves antioxidant capacity but also declines oxidative damages and apoptosis through reducing Bax levels and enhancing Bcl-2 value.

Shen Shuai II Recipe Attenuates Apoptosis in 5/6 Renal Ablation/Infarction Rats by Inhibiting p53 and the Mitochondrial Pathway of Apoptosis

Background. Chronic kidney disease (CKD) is a global health burden with high mortality and morbidity. Clinical efficacy has been demonstrated for Shen Shuai II Recipe (SSR), an approved and widely used Chinese herbal medicine for over 20 years in China, to attenuate CKD progression. In this study, we explored the underlying molecular mechanisms of SSR benefits and studied its effects on apoptosis, a critical process in CKD development and progression. CKD was induced in rats with 5/6 renal ablation and infarction (A/I). Eight weeks after SSR treatment, we mainly assessed the severity of renal injury and fibrosis, the translocation of apoptotic factors in the mitochondrial apoptosis pathway, the degree of mitochondrial dysfunction, and the nuclear and mitochondrial translocation of p53. Furthermore, we detected the interaction of p53 with antiapoptotic Bcl-xL and Bcl-2 proteins. Our results showed that SSR significantly attenuated renal injury and fibrosis and inhibited the mitochondrial accumulation of proapoptotic proteins Bax and Puma and release of cytochrome c from mitochondria to the cytosol in a rat CKD model. In addition, SSR also improved the mitochondrial function and inhibited the nuclear and mitochondrial translocation of p53. In addition, SSR suppressed the p53 transactivation and the interaction of p53 with Bcl-xL and Bcl-2. These results suggested that SSR could block apoptosis in CKD by inhibiting p53 transcriptional-dependent and transcriptional-independent proapoptotic function and the mitochondrial pathway of apoptosis.

Exercise stimulates beneficial adaptations to diminish doxorubicin-induced cellular toxicity

Doxorubicin (DOX) is a highly effective antitumor agent used for the treatment of a wide range of cancers. Unfortunately, DOX treatment results in cytotoxic side effects due to its accumulation within off-target tissues. DOX-induced cellular toxicity occurs as a result of increased oxidative damage, resulting in apoptosis and cell death. While there is no standard-of-care practice to prevent DOX-induced toxicity to healthy organs, exercise has been shown to prevent cellular dysfunction when combined with DOX chemotherapy. Endurance exercise stimulates numerous biochemical adaptations that promote a healthy phenotype in several vulnerable tissues without affecting the antineoplastic properties of DOX. Therefore, for the development of an effective strategy to combat the pathological effects of DOX, it is important to determine the appropriate exercise regimen to prescribe to cancer patients receiving DOX therapy and to understand the mechanisms responsible for exercise-induced protection against DOX toxicity to noncancer cells. This review summarizes the cytotoxic effects of DOX on the heart, skeletal muscle, liver, and kidneys and discusses the current understanding of the clinical benefits of regular physical activity and the potential mechanisms mediating the positive effects of exercise on each organ system.

Oxidative Imbalance and Kidney Damage in Cafeteria Diet-Induced Rat Model of Metabolic Syndrome: Effect of Bergamot Polyphenolic Fraction

Obesity is a potent risk factor for kidney disease as it increases the possibility of developing diabetes and hypertension, and it has a direct impact on the development of chronic kidney disease and end-stage renal disease. In this study, we tested the effect of bergamot polyphenolic fraction in a cafeteria with diet-fed rats, an excellent experimental model for studying human metabolic syndrome, as it is able to induce severe obesity with insulin resistance and high plasma triglyceride levels more efficiently than a traditional lard-based high-fat diet used in rodent models. We analyzed the plasmatic oxidative balance by photometric tests, and the expression of cytoplasmic antioxidant enzymes (superoxide dismutase 1 and glutatione S-tranferasi P1) and apoptotic markers (Caspase 8 and 9) in kidney tissues by Western blot analysis. Our results clearly showed that the cafeteria diet induces a marked pro-oxidant effect: significant reduction of plasmatic antioxidant capacity; downregulation of cytoplasmic antioxidant enzymes expression; and activation of apoptotic pathways. All these hallmarks of redox disequilibrium were mitigated by treatment with polyphenolic fraction of bergamot, highlighting its antioxidant effect in the metabolic syndrome. Our data show that the link between obesity and renal damage could be represented by oxidative stress.

Aerobic interval exercise improves renal functionality and affects mineral metabolism in obese Zucker rats

Obesity, metabolic syndrome, and renal injury are considered risk factors for type 2 diabetes, as well as kidney disease. Functional and structural changes in the kidney as consequence of obesity and metabolic syndrome may lead to impaired mineral metabolism in what is known as chronic kidney disease-mineral and bone disorder. Lifestyle interventions such as physical activity are good strategies to manage these pathologies and therefore, prevent the loss of kidney functionality and related complications in mineral metabolism. In this study, we have used 40 male Zucker rats that were randomly allocated into four different experimental groups, two of them (an obese and a lean one) performed an aerobic interval training protocol, and the other two groups were sedentary. At the end of the experimental period (8 wk), urine, plasma, and femur were collected for biochemical and mineral composition analysis, whereas the kidney was processed for histological studies. The obese rats exhibited albuminuria, glomerulosclerosis, and hypertrophy in glomeruli and renal tubule in some areas, together with alterations in mineral content of plasma but not of femur. The training protocol prevented the generation of albuminuria and glomerulosclerosis, showing a significant action on plasma and bone mineral levels. Therefore, the specific training protocol used in this study was able to prevent the development of diabetic nephropathy and affected the metabolism of certain minerals.

Effects of voluntary exercise on apoptosis and cortisol after chronic restraint stress in mice

[Purpose]

To determine whether voluntary exercise (wheel running) has the potential of relieving stress.

[Methods]

In this study, restraint stress with or without voluntary wheel running was performed for mice housed in individual cages. A total of 21 ICR male mice were assigned into control (CON), restraint stress with voluntary exercise (RSVE), or restraint stress (RS) without voluntary exercise groups (n = 7 each).

[Results]

No significant difference in body weight increase was found among the three groups, although CON and RS groups had a tendency of having smaller body weight increase compared to the RSVE group. No significant difference in the expression level of liver heat shock protein 70, Bcl-2, or p53 was found among the three groups. However, caspase-3 protein level in RS group was significantly higher than that in the other two groups. Blood cortisol concentration in RS was higher (p < 0.05) than that in RSVE or CON group. It was the lowest (p < 0.05) in the RSVE group.

[Conclusion]

Our findings suggest that apoptosis caused by chronic restraint stress might be suppressed by voluntary exercise in mice.