Endurance Training Regulates Expression of Some Angiogenesis-Related Genes in Cardiac Tissue of Experimentally Induced Diabetic Rats

Cardiovascular adaptations and pathological changes induced by spaceflight: from cellular mechanisms to organ-level impacts

The advancement in extraterrestrial exploration has highlighted the crucial need for studying how the human cardiovascular system adapts to space conditions. Human development occurs under the influence of gravity, shielded from space radiation by Earth's magnetic field, and within an environment characterized by 24-hour day-night cycles resulting from Earth's rotation, thus deviating from these conditions necessitates adaptive responses for survival. With upcoming manned lunar and Martian missions approaching rapidly, it is essential to understand the impact of various stressors induced by outer-space environments on cardiovascular health. This comprehensive review integrates insights from both actual space missions and simulated experiments on Earth, to analyze how microgravity, space radiation, and disrupted circadian affect cardiovascular well-being. Prolonged exposure to microgravity induces myocardial atrophy and endothelial dysfunction, which may be exacerbated by space radiation. Mitochondrial dysfunction and oxidative stress emerge as key underlying mechanisms along with disturbances in ion channel perturbations, cytoskeletal damage, and myofibril changes. Disruptions in circadian rhythms caused by factors such as microgravity, light exposure, and irregular work schedules, could further exacerbate cardiovascular issues. However, current research tends to predominantly focus on disruptions in the core clock gene, overlooking the multifactorial nature of circadian rhythm disturbances in space. Future space missions should prioritize targeted prevention strategies and early detection methods for identifying cardiovascular risks, to preserve astronaut health and ensure mission success.

The effect of high-intensity interval training on type 2 diabetic muscle: A metabolomics-based study

Background

This study aimed to investigate the effect of eight weeks of high-intensity interval training (HIIT) on muscle metabolism in rats with type 2 diabetes (T2D) using metabolomics approaches.

Methods

20 male Wistar rats at the age of 8 weeks-were assigned to four groups of five, each in the group randomly: control (CTL), type 2 diabetes (DB), HIIT (EX), and type 2 diabetes + HIIT (DBX). T2D was induced by two months of a high-fat diet plus a single dose of streptozotocin (35 mg/kg). Rats in the EX and DBX groups performed eight weeks of HIIT (running at 80-100 % of Vmax, 4-10 intervals). NMR spectroscopy was used to determine the changes in the muscle metabolome profile after training.

Results

Changes in metabolite abundance following exercise revealed distinct clustering in multivariate analysis. The essential metabolite changes between the DB and CTL groups were arginine metabolism, purine metabolism, phosphate pathway, amino sugar metabolism, glutathione metabolism, and aminoacyl-tRNA biosynthesis. However, Arginine biosynthesis, pyrimidine metabolism, aminoacyl-tRNA biosynthesis, and alanine, aspartate, and glutamate metabolism were altered between the DBX and DB groups.

Conclusion

These results suggest that eight weeks of HIIT could reverse metabolic changes induced by T2D in rat muscles, contributing to reduced FBG and HOMA-IR levels.

The effect of 12 weeks of aerobic exercise training with or without saffron supplementation on diabetes-specific markers and inflammation in women with type 2 diabetes: A randomized double-blind placebo-controlled trial

This study was conducted to investigate the effects of 12 weeks of aerobic exercise (AT) and saffron supplementation on hemostasis, inflammatory markers, and insulin resistance in obese women diagnosed with type 2 diabetes (T2D). A total of 44 women with T2D (mean age: 54.12 ± 5.63 years, mean BMI: 31.15 ± 1.50 kg/m2, HbA1c: 85 ± 4.2 mmol/mol) were included in a randomized, double-blind, placebo-controlled study. We were randomly assigned to one of four groups (n = 11 per group): saffron + training (ST), placebo + training (PT), saffron supplement (SS), and placebo (P). The ST and PT groups completed 12 weeks of AT (three sessions per week of mild to moderate intensity). The ST and SS groups were administered a daily dose of 200 mg of saffron powder for 12 weeks. Fasting blood samples were collected 48 h before the first AT session and/or nutritional supplementation and 48 h after the last AT session and/or nutritional supplementation. Post-evaluation, homeostatic model assessment of insulin resistance value (HOMA-IR, p < 0.001) and serum levels of glucose (p < 0.001), fibrinogen (FIB, p < 0.001), homocysteine (HCY, p < 0.001), interleukin-6 (IL-6, p < 0.001), and tumor necrosis factor α (TNFα, p < 0.001) showed significant reduction in the ST, PT, and SS groups compared to the P group (p < 0.05). In particular, the ST group showed a more significant reduction in all variables compared to the PT and SS groups (p < 0.05). Our results suggest that a 12-week intervention with AT and saffron supplementation can independently improve markers related to hemostasis, inflammation, and insulin resistance. However, their combination showed the greatest effectiveness on the above markers.

Changes in the hippocampal level of tau but not beta-amyloid may mediate anxiety-like behavior improvement ensuing from exercise in diabetic female rats

BACKGROUND

In the present study, we investigated the effect of high-intensity interval training (HIIT) on cognitive behaviors in female rats with a high-fat diet + streptozotocin (STZ)-induced type 2 diabetes.

METHODS

Twenty-four female rats were divided into four groups randomly (n = 6): control (C), control + exercise (Co + EX), diabetes mellitus (type 2) (T2D), and diabetes mellitus + exercise (T2D + EX). Diabetes was induced by a two-month high-fat diet and a single dose of STZ (35 mg/kg) in the T2D and T2D + EX groups. The Co + EX and T2D + EX groups performed HIIT for eight weeks (five sessions per week, running on a treadmill at 80-100% of VMax, 4-10 intervals). Elevated plus maze (EPM) and open field test (OFT) were used for assessing anxiety-like behaviors, and passive avoidance test (PAT) and Morris water maze (MWM) were applied for evaluating learning and memory. The hippocampal levels of beta-amyloid (Aβ) and Tau were also assessed using Western blot.

RESULTS

An increase in fasting blood glucose (FBG), hippocampal level of Tau, and a decrease in the percentage of open arm time (%OAT) as an index of anxiety-like behavior were seen in the female diabetic rats which could be reversed by HIIT. In addition, T2D led to a significant decrease in rearing and grooming in the OFT. No significant difference among groups was seen for the latency time in the PAT and learning and memory in the MWM.

CONCLUSIONS

HIIT could improve anxiety-like behavior at least in part through changes in hippocampal levels of Tau.

Role of CaMKII in diabetes induced vascular injury and its interaction with anti-diabetes therapy

Diabetes mellitus is a metabolic disorder denoted by chronic hyperglycemia that drives maladaptive structural changes and functional damage to the vasculature. Attenuation of this pathological remodeling of blood vessels remains an unmet target owing to paucity of information on the metabolic signatures of this process. Ca2+/calmodulin-dependent kinase II (CaMKII) is expressed in the vasculature and is implicated in the control of blood vessels homeostasis. Recently, CaMKII has attracted a special attention in view of its chronic upregulated activity in diabetic tissues, yet its role in the diabetic vasculature remains under investigation.This review highlights the physiological and pathological actions of CaMKII in the diabetic vasculature, with focus on the control of the dialogue between endothelial (EC) and vascular smooth muscle cells (VSMC). Activation of CaMKII enhances EC and VSMC proliferation and migration, and increases the production of extracellular matrix which leads to maladaptive remodeling of vessels. This is manifested by activation of genes/proteins implicated in the control of the cell cycle, cytoskeleton organization, proliferation, migration, and inflammation. Endothelial dysfunction is paralleled by impaired nitric oxide signaling, which is also influenced by CaMKII signaling (activation/oxidation). The efficiency of CaMKII inhibitors is currently being tested in animal models, with a focus on the genetic pathways involved in the regulation of CaMKII expression (microRNAs and single nucleotide polymorphisms). Interestingly, studies highlight an interaction between the anti-diabetic drugs and CaMKII expression/activity which requires further investigation. Together, the studies reviewed herein may guide pharmacological approaches to improve health-related outcomes in patients with diabetes.

Exercise training improves diabetic renal injury by reducing fetuin-A, oxidative stress and inflammation in type 2 diabetic rats

Background

Diabetic kidney disease (DKD) stands as a primary contributor to end-stage renal disease, associated with heightened mortality in cardiovascular diseases. This study aimed to explore the impact of an eight-week high-intensity interval training (HIIT) on renal injury in diabetic rats.

Methods

Twenty-eight male Wistar rats were randomly allocated into four groups: healthy control (CTL), diabetic control (DC), exercise (EX), and diabetes-exercise (D + EX). Induction of diabetes in the DC and D + EX groups occurred through a two-month high-fat diet followed by a single dose of 35 mg/kg streptozotocin (STZ). Rats in the EX and D + EX groups underwent 4-10 intervals of HIIT (80-100% Vmax) over 8 weeks. Subsequently, pathological and biochemical parameters were assessed in the serum and kidney tissue of the experimental groups.

Results

In the DC group, diabetes led to elevated kidney damage, glomerulosclerosis, fasting blood glucose (FBG), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index, animal weight, kidney dysfunction, albuminuria, and glomerular filtration rate. Additionally, serum and kidney levels of fetuin-A increased, along with kidney levels of KIM-1. Mechanistically, diabetes induction resulted in kidney inflammation by elevating levels of tumor necrosis factor-alpha (TNF-α), transforming growth factor beta (TGF-β), and interleukin 6 (IL-6), while reducing IL-10 levels and increasing the IL-6/IL-10 ratio. Furthermore, diabetes triggered renal oxidative stress, evidenced by increased Malondialdehyde (MDA) levels and decreased levels of glutathione peroxidase (GPx), catalase, and superoxide dismutase (SOD). HIIT mitigated the adverse effects of diabetes in the D + EX group compared to the DC group.

Conclusion

Our findings suggest that HIIT ameliorates type 2 diabetes (T2D)-induced kidney damage by mitigating inflammation, lowering serum levels of fetuin-A, and bolstering antioxidant defenses. This study highlights the potential of HIIT as a time-efficient intervention for diabetic nephropathy.

ATP releasing channels and the ameliorative effects of high intensity interval training on diabetic heart: a multifaceted analysis

Type 2 diabetes (T2D) can cause severe cardiac complications at functional, histologic and molecular levels. These pathological complications could be mediated by ATP-releasing channels such as Panx1 and ATP receptors, in particular P2X7. The aim of our study was to investigate the effect of high-intensity interval training (HIIT) on T2D-induced cardiac complications at the functional, histopathological and molecular levels, with a particular focus on ATP-releasing channels. 48 male Wistar rats at the age of 8 weeks were randomly allocated into four groups: control (Con), Diabetes (T2D), Training (TR), and Diabetes + Training (T2D + TR). T2D was induced by a high-fat diet plus a low dose (35 mg/kg) of STZ administration. Rats in the TR and T2D + TR groups underwent an 8-weeks training program involving intervals ranging from 80 to 100% of their maximum running speed (Vmax), with 4-10 intervals per session. Protein expression of Interleukin 1β (IL1β), Interleukin 10 (IL-10), Pannexin 1 (Panx1), P2X7R (purinergic P2X receptor 7), NLRP1 (NLR Family Pyrin Domain Containing 1), BAX, and Bcl2 were measured in the heart tissue. Additionally, we assessed heart function, histopathological changes, as well as insulin resistance using the homeostasis model assessment of insulin resistance (HOMA-IR). In contrast to the T2D group, HIIT led to increased protein expression of Bcl2 and IL-10 in the heart. It also resulted in improvements in systolic and diastolic blood pressures, heart rate, ± dp/dt (maximum and minimum changes in left ventricular pressure), while reducing protein expression of IL-1β, Panx1, P2X7R, NLRP1, and BAX levels in the heart. Furthermore, left ventricular diastolic pressure (LVDP) was reduced (P ≤ 0.05). Moreover, heart lesion scores increased with T2D but decreased with HIIT, along with a reduction in fibrosis percentage (P ≤ 0.05). The results of this study suggest that the cardioprotective effects of HIIT on the diabetic heart may be mediated by the modulation of ATP-releasing channels. This modulation may lead to a reduction in inflammation and apoptosis, improve cardiac function, and attenuate cardiac injury and fibrosis.

Lactate-induced autophagy activation: unraveling the therapeutic impact of high-intensity interval training on insulin resistance in type 2 diabetic rats

Impaired autophagy is a hallmark of diabetes. The current study proposed to investigate if high intensity interval training (HIIT) induced lactate accumulation could stimulate autophagy in type 2 diabetic male rats. 28 male Wistar rats were randomly assigned into four groups: Healthy Control (CO), Diabetes Control (T2D), Exercise (EX), and Diabetes + Exercise (T2D + EX). Diabetes was induced by feeding high-fat diet and administrating single dose of streptozotocin (35 mg/kg). After becoming diabetic, the animals in the exercise groups (EX and T2D + EX) performed an eight-week HIIT (4-10 interval, 80-100% Vmax, 5 days per week). Serum levels of lactate, glucose and insulin as well as the levels of lactate, pyruvate, lactate transporter monocarboxylate transporter 1 (MCT1), phosphorylated mitogen-activated protein kinases (p-MAP 1 and 2), phosphorylated extracellular signal-regulated protein kinases 1 and 2 (p-ERK 1 and 2), mammalian target of rapamycin (p-mTOR), ribosomal protein S6 kinase beta-1 (p-70S6k), p90 ribosomal S6 kinases (p-90RSK), autophagy related 7 (ATG7), Beclin-1, microtubule-associated protein 1A/1B, and 2A/2B -light chain 3 levels (LC3-I), (LC3- II), (LC3I/LC3II) in soleus muscle were measured. Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) and serum glucose was lower in T2D + EX compared to T2D group (P < 0.0001). While serum and soleus muscle levels of lactate was not different between T2D and T2D + Ex, the levels of Pyruvate (P < 0.01), MCT1, p-ERK1/2, p-mTOR, p70S6k, P-90RSK, ATG7, LC3-II, and LC3-II/LC3I ratios were higher in T2D + EX compared to T2D group (P < 0.0001). We concluded that eight weeks of high-intensity interval training could activated ERK/P90SRK while inhibiting mTOR/P70S6K signaling pathway in lactate dependent manner. It means increased autophagy which resulted in improve insulin resistance (IR) and reduce blood glucose.

The Effects of Eight Weeks of Circuit Resistance Training on Serum METRNL Levels and Insulin Resistance in Individuals with Type 2 Diabetes

Purpose

The effects of exercise training on meteorin-like protein (METRNL), one of the newest factors involved, is one of the treatment strategies for diabetes. The present study aimed to investigate the effects of circuit resistance training on METRNL and insulin resistance in people with Type 2 Diabetes Mellitus (T2DM).

Methods

Twenty eligible diabetics volunteered to participate and were randomly divided into control (n = 10, age = 51 ± 1 years, BMI = 27.43 ± 0.98 kg/m2) and experimental groups (n = 10, age = 51 ± 1 years, BMI = 30.12 ± 0.92 kg/m2). The circuit resistance training (10 exercises) used in this study was performed for eight weeks (3 non-consecutive sessions/week, 2-4 circuits, 40%-80% 1RM, 15-6 repetitions). The rest period between each exercise was 20-30 s, and the rest between each circuit was 3 min. Participants in the control groups were asked to maintain their daily physical activities and not to engage in any systematic training program throughout the study.

Results

METRNL did not change significantly in the control group (0.66 ± 0.06 to 0.7 ± 0.04), but it increased significantly in the experimental group (0.3 ± 0.06 to 0.71 ± 0.03, p = 0.001); In contrast, FBS increased significantly in the control group (122.8 ± 7.5 to 192.8 ± 14.9) and decreased significantly in the experimental group (197.2 ± 7.1 to 135.00 ± 14.00, p = 0.001). Insulin in control and experimental groups did not change significantly (p = 0.96); However, the IR of the control group increased significantly (6.37 ± 1.46 to 9.6 ± 1.53), but its level was significantly attenuated in the experimental group (4.89 ± 1.37 to 4.38 ± 1.44, p = 0.028).

Conclusion

Eigth weeks of circuit resistance training with low to high intensities can increase the resting levels of METRNL in men with T2DM, which can be significantly associated with the improved fasting blood glucose levels and insulin resistance.

High-Intensity Interval Training Ameliorates Molecular Changes in the Hippocampus of Male Rats with the Diabetic Brain: the Role of Adiponectin

Alzheimer's disease (AD) is closely related to type 2 diabetes (T2D). This study investigated the impact of high-intensity interval training (HIIT) on diabetes-induced disturbances in AD-related factors (including AMP-activated protein kinase (AMPK), glycogen synthase kinase-3β (GSK3β), and tau protein) in the hippocampus, with the main focus on adiponectin signaling.In total, 28 male Wistar rats at the age of 8 weeks were randomly assigned to four groups (n = 7 in each group): control (Con), type 2 diabetes (T2D), HIIT (Ex), and type 2 diabetes + HIIT (T2D + Ex). T2D was induced by a high-fat diet plus a single dose of streptozotocin (STZ). Rats in Ex and T2D + Ex groups performed 8 weeks of HIIT (running at 8-95% of V_max, 4-10 intervals). Insulin and adiponectin levels in serum and hippocampus were measured along with hippocampal expression of insulin and adiponectin receptors, phosphorylated AMPK, dephosphorylated GSK3β, and phosphorylated tau. Homeostasis model assessment for insulin resistance (HOMA-IR), homeostasis model assessment for insulin resistance beta (HOMA-β), and quantitative insulin sensitivity check index (QUICKI) were calculated to assess insulin resistance and sensitivity. T2D decreased insulin and adiponectin levels in serum and hippocampus, as well as the hippocampal levels of insulin and adiponectin receptors and AMPK, but increased GSK3β and tau in the hippocampus. HIIT reversed diabetes-induced impairments and consequently decreased tau accumulation in the hippocampus of diabetic rats. HOMA-IR, HOMA-β, and QUICKI were improved in Ex and T2D + Ex groups. Overall, our results confirmed that T2D has undesirable effects on the levels of some Alzheimer's-related factors in the hippocampus, and HIIT could ameliorate these impairments in the hippocampus.

Interactions between the ERK1/2 signaling pathway and PCAF play a key role in PE‑induced cardiomyocyte hypertrophy

Cardiomyocyte hypertrophy is a compensatory phase of chronic heart failure that is induced by the activation of multiple signaling pathways. The extracellular signal-regulated protein kinase (ERK) signaling pathway is an important regulator of cardiomyocyte hypertrophy. In our previous study, it was demonstrated that phenylephrine (PE)-induced cardiomyocyte hypertrophy involves the hyperacetylation of histone H3K9ac by P300/CBP-associated factor (PCAF). However, the upstream signaling pathway has yet to be fully identified. In the present study, the role of the extracellular signal-regulated protein kinase (ERK)1/2 signaling pathway in PE-induced cardiomyocyte hypertrophy was investigated. The mice cardiomyocyte hypertrophy model was successfully established by treating cells with PE in vitro. The results showed that phospho-(p-)ERK1/2 interacted with PCAF and modified the pattern of histone H3K9ac acetylation. An ERK inhibitor (U0126) and/or a histone acetylase inhibitor (anacardic acid; AA) attenuated the overexpression of phospho-ERK1/2 and H3K9ac hyperacetylation by inhibiting the expression of PCAF in PE-induced cardiomyocyte hypertrophy. Moreover, U0126 and/or AA could attenuate the overexpression of several biomarker genes related to cardiac hypertrophy (myocyte enhancer factor 2C, atrial natriuretic peptide, brain natriuretic peptide and β-myosin heavy chain) and prevented cardiomyocyte hypertrophy. These results revealed a novel mechanism in that AA protects against PE-induced cardiomyocyte hypertrophy in mice via the ERK1/2 signaling pathway, and by modifying the acetylation of H3K9ac. These findings may assist in the development of novel methods for preventing and treating hypertrophic cardiomyopathy.