Proteomic Mechanism of Myocardial Angiogenesis Augmented by Remote Ischemic Training of Skeletal Muscle in Rabbit

Amelioration of ischemic cardiomyopathy in patients using physiological ischemic training

BACKGROUND

This study aimed to observe the effect and potential mechanism of physiological ischemic training (PIT) in patients with ischemic cardiomyopathy.

METHODS

A total of 165 patients with ischemic cardiomyopathy were randomly selected by the convenience sampling method and were divided into the control and experimental groups. The control group received conventional drug treatment, while the experimental group received additional PIT. All patients were followed up for 6 months and renin-angiotensin-aldosterone system (RAS) activity parameters and myocardial remodeling indicators were recorded.

RESULTS

After the 6‑month intervention, cardiac function indicators in the two groups were significantly improved compared with before intervention (all P < 0.01), but the experimental group showed significantly more improvement compared with the control group (all P < 0.01). Similarly, RAS activity parameters and myocardial remodeling indicators of the two groups were significantly reduced after intervention compared with before intervention (all P < 0.01). However, the experimental group showed significantly lower myocardial remodeling indicators than the control group (all P < 0.01). Vascular endothelial growth factor (VEGF) and nitric oxide (NO) concentrations in peripheral blood in the experimental group were significantly increased after intervention compared with before intervention (both P < 0.01).

CONCLUSIONS

PIT can be applied in patients with ischemic cardiomyopathy on the basis of the original standardized drug treatment. PIT ameliorates cardiac blood flow reserve by increasing VEGF and NO concentrations in the peripheral blood, as well as by inhibiting the RAS system and myocardial remodeling. This ultimately improves the patient's cardiac function to a greater extent.

Over-expression of JAZF1 promotes cardiac microvascular endothelial cell proliferation and angiogenesis via activation of the Akt signaling pathway in rats with myocardial ischemia-reperfusion

Myocardial ischemia-reperfusion (I/R) injury is caused by endothelial dysfunction and enhanced oxidative stress. The overexpression of JAZF1, a zinc finger protein, has been reported to promote cell proliferation and suppress myogenic differentiation in type 2 diabetes. However, the involvement of JAZF1 in myocardial I/R injury remains to be unclear. The current study aims to investigate the role by which JAZF1 influences cardiac microvascular endothelial cells (CMECs) in a rat model of myocardial I/R injury. A total of 50 rats were established as a myocardial I/R model to isolate CMECs, with alterations in JAZF1 expression. After that, the gain- or loss-function of JAZF1 on the proliferation, apoptosis and tube formation ability of CMECs were evaluated by a series of in vitro experiments. Results indicated that JAZF1 was down-regulated in CMECs of rats with myocardial I/R injury. After treatment with JAZF1, the levels of VEGF, Bcl-2, PDGF and p-Akt/Akt were all increased; however, the expression of Bax, caspase-3, caspase-9, p-Bad/Bad, c-caspase-3/caspase-3, c-caspase-9/caspase-9, and p-FKHR/FKHR exhibited decreased levels; CMEC proliferation and angiogenesis were increased, while cell apoptosis was attenuated. CMECs transfected with JAZF1 shRNA exhibited the contrary tendencies. The key findings of this study suggest that the over-expression of JAZF1 alleviates myocardial I/R injury by enhancing proliferation and angiogenesis of CMECs and in turn inhibiting apoptosis of CMECs via the activation of the Akt signaling pathway.

Randomized clinical trial of physiological ischemic training for patients with coronary heart disease complicated with heart failure: Safety of training, VEGF of peripheral blood and quality of life

Effects of a 12-week physiological ischemic training (PIT) programme on safety of training and quality of life (QOL) in patients with coronary heart disease (CHD) complicated with heart failure were evaluated. A total of 30 patients with CHD complicated with heart failure were randomized to either an intervention group (n=15) or to controls (n=15) after baseline testing. A 12-week, 5 times a week, maximum subjective force group PIT was conducted. Safety of the training was measured with ECG and heart rate and blood pressure, QOL was measured using the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and vascular endothelial growth factor (VEGF) was measured with peripheral blood. VEGF and MLHFQ were improved in the intervention group. The finding of the study shows PIT is safe to patients with CHD complicated with heart failure by improving VEGF of peripheral blood and QOL.

Does stem cell therapy induce myocardial neoangiogenesis? Histological evaluation in an ischemia/reperfusion animal model

BACKGROUND

In an experimental model in the rabbit, a myocardial ischemia-reperfusion injury was obtained. Subsequently, the effects of homologous bone marrow stem cell (BMSC) administration were studied.

METHODS

In 21 New Zealand adult rabbits, ischemia/reperfusion damage was induced by temporary occlusion of the anterior descending coronary artery. Homologous BMSCs were isolated, cultured and re-suspended for injection at the level of the ischemic zone. We evaluated the proangiogenetic effect of intramyocardial injections of BMSC at the peri-infarcted area. Histological evaluations were made after 20 days from the surgical procedure.

RESULTS

In rabbits treated with intramyocardial BMSC administration, we demonstrated histologically capillary neoangiogenesis, without signs of tissue immunological reaction or of generation of new myocardial cells. On the contrary, only minimal neovascular supply was detected in rabbits treated with intravenous administration of BMSC. Only typical signs of ischemic myocardium injury were observed in the control group.

CONCLUSION

These observations suggest that the effect of direct BMSC administration in ischemic myocardium could promote a capillary neoangiogenesis, which helps to prevent ischemic myocardial damage.

Proteomic-Biostatistic Integrated Approach for Finding the Underlying Molecular Determinants of Hypertension in Human Plasma

Despite advancements in lowering blood pressure, the best approach to lower it remains controversial because of the lack of information on the molecular basis of hypertension. We, therefore, performed plasma proteomics of plasma from patients with hypertension to identify molecular determinants detectable in these subjects but not in controls and vice versa. Plasma samples from hypertensive subjects (cases; n=118) and controls (n=85) from the InGenious HyperCare cohort were used for this study and performed mass spectrometric analysis. Using biostatistical methods, plasma peptides specific for hypertension were identified, and a model was developed using least absolute shrinkage and selection operator logistic regression. The underlying peptides were identified and sequenced off-line using matrix-assisted laser desorption ionization orbitrap mass spectrometry. By comparison of the molecular composition of the plasma samples, 27 molecular determinants were identified differently expressed in cases from controls. Seventy percent of the molecular determinants selected were found to occur less likely in hypertensive patients. In cross-validation, the overall R2 was 0.434, and the area under the curve was 0.891 with 95% confidence interval 0.8482 to 0.9349, P<0.0001. The mean values of the cross-validated proteomic score of normotensive and hypertensive patients were found to be -2.007±0.3568 and 3.383±0.2643, respectively, P<0.0001. The molecular determinants were successfully identified, and the proteomic model developed shows an excellent discriminatory ability between hypertensives and normotensives. The identified molecular determinants may be the starting point for further studies to clarify the molecular causes of hypertension.

Isometric Exercise Training for Managing Vascular Risk Factors in Mild Cognitive Impairment and Alzheimer's Disease

Alzheimer’s disease (AD) is the most common form of dementia diagnosed amongst the elderly. Mild cognitive impairment (MCI) is a condition often indicative of the earliest symptomatology of AD with 10%–15% of MCI patients reportedly progressing to a diagnosis of AD. Individuals with a history of vascular risk factors (VRF’s) are considered high risk candidates for developing cognitive impairment in later life. Evidence suggests that vascular injury resulting from untreated VRF’s promotes progression from MCI to AD and exacerbates the severity of dementia in AD, and neuroimaging studies have found that the neurodegenerative processes associated with AD are heavily driven by VRF’s that promote cerebral hypoperfusion. Subsequently, common links between vascular disorders such as hypertension and neurodegenerative disorders such as AD include compromised vasculature, cerebral hypoperfusion and chronic low grade inflammation (a hallmark of both hypertension and AD). Exercise has been demonstrated to be an effective intervention for blood pressure management, chronic low grade inflammation and improvements in cognition. Data from recent analyses suggests that isometric exercise training (IET) may improve vascular integrity and elicit blood pressure reductions in hypertensives greater than those seen with dynamic aerobic and resistance exercise. IET may also play an effective role in the management of VRF’s at the MCI stage of AD and may prove to be a significant strategy in the prevention, attenuation or delay of progression to AD. A plausible hypothesis is that the reactive hyperemia stimulated by IET initiates a cascade of vascular, neurotrophic and neuro-endocrine events that lead to improvements in cognitive function.

Physiological Ischemic Training Promotes Brain Collateral Formation and Improves Functions in Patients with Acute Cerebral Infarction

Objectives

To observe the effectiveness and mechanisms of physiological ischemic training (PIT) on brain cerebral collateral formation and functional recovery in patients with acute cerebral infarction.

Methods

20 eligible patients with acute cerebral infarction were randomly assigned to either PIT group (n = 10) or Control group (n = 10). Both groups received 4 weeks of routine rehabilitation therapy, while an additional session of PIT, which consisted of 10 times of maximal voluntary isometric handgrip for 1 min followed by 1 min rest, was prescribed for patients in the PIT groups. Each patient was trained with four sections a day and 5 days a week for 4 weeks. The Fugl–Meyer Assessment (FMA), the Modified Barthel Index (MBI), and the short-form 36-item health survey questionnaire (SF-36) were applied for the evaluation of motor impairment, activity of daily living, and quality of life at the baseline and endpoint. MRI was applied to detect the collateral formation in the brain. The concentration of vascular endothelial growth factor (VEGF) and endothelial progenitor cells (EPCs) number in plasma were also tested at the endpoint.

Results

Demographic data were consistent between experimental groups. At the endpoint, the scores of the FMA, MBI, and SF-36 were significantly higher than that at baseline. As compared to the Control group, the score of FMA and SF-36 in PIT group was significantly higher, while no significant difference was detected between groups in terms of MBI. Both groups had significantly higher cerebral blood flow (CBF) level at endpoint as compared to that at baseline. Moreover, the CBF level was even higher in the PIT group as compared to that in the Control group after 4 weeks of training. The same situations were also found in the plasma VEGF and EPCs assessment. In addition, positive correlations were found between FMA score and CBF level (r = 0.686, p < 0.01), CBF level and VEGF concentration (r = 0.675, p < 0.01), and VEGF concentration and EPC number (r = 0.722, p < 0.01).

Conclusion

PIT may be effective in increasing the expression of VEGF and recruitment of EPCs and in turn promote the formation of brain collateral circulation. The positive correlations may demonstrate a potential association between biological and functional parameters, and PIT may be able to improve the motor function, activity of daily living, and quality of life in patients with stroke.

The evolving concept of physiological ischemia training vs. ischemia preconditioning

Ischemic heart diseases are the leading cause of death with increasing numbers of patients worldwide. Despite advances in revascularization techniques, angiogenic therapies remain highly attractive. Physiological ischemia training, which is first proposed in our laboratory, refers to reversible ischemia training of normal skeletal muscles by using a tourniquet or isometric contraction to cause physiologic ischemia for about 4 weeks for the sake of triggering molecular and cellular mechanisms to promote angiogenesis and formation of collateral vessels and protect remote ischemia areas. Physiological ischemia training therapy augments angiogenesis in the ischemic myocardium by inducing differential expression of proteins involved in energy metabolism, cell migration, protein folding, and generation. It upregulates the expressions of vascular endothelial growth factor, and induces angiogenesis, protects the myocardium when infarction occurs by increasing circulating endothelial progenitor cells and enhancing their migration, which is in accordance with physical training in heart disease rehabilitation. These findings may lead to a new approach of therapeutic angiogenesis for patients with ischemic heart diseases. On the basis of the promising results in animal studies, studies were also conducted in patients with coronary artery disease without any adverse effect in vivo, indicating that physiological ischemia training therapy is a safe, effective and non-invasive angiogenic approach for cardiovascular rehabilitation. Preconditioning is considered to be the most protective intervention against myocardial ischemia-reperfusion injury to date. Physiological ischemia training is different from preconditioning. This review summarizes the preclinical and clinical data of physiological ischemia training and its difference from preconditioning.

Impact of remote physiological ischemic training on vascular endothelial growth factor, endothelial progenitor cells and coronary angiogenesis after myocardial ischemia

OBJECTIVE

This experimental study investigates the potential role of physiological ischemic training (PIT) of remote limbs on vascular endothelial growth factor (VEGF), endothelial progenitor cells (EPCs) and myocardial angiogenesis after myocardial ischemia.

METHODS

Forty-two rabbits were assigned into six groups at random: sham-operated (SO), training only (TO), myocardial ischemia (MI), PIT, EPC promoter (PIT+), and EPC inhibitor (PIT-). MI was experimentally induced by implanting a constrictor around the left ventricular branch. The PIT procedure included three 3-min cycles of cuff inflations on the hind limbs followed by a 5 min reperfusion. VEGF mRNA, protein and EPC numbers were measured in plasma and myocardium. Capillary density (CD), coronary blood flow (CBF) and coronary collateral blood flow (CCBF) were also determined.

RESULTS

Groups were compared using non-parametric statistics and associations between agents were explored with fractional polynomial regression. VEGF-mRNA and -protein levels were highest in PIT+ and PIT. PIT differed significantly from SO, TO, MI, and PIT- regarding VEGF-mRNA and -protein in plasma and VEGF-protein in myocardium. EPCs were highest in PIT+ followed by PIT. PIT differed significantly from SO, TO, MI, and PIT- regarding plasma EPCs. CD, CCBF and CCBF/CBF were significantly increased in PIT+ and PIT as compared to controls. PIT- did not differ significantly from SO and TO. VEGF explained up to 43% of variance in EPCs. EPCs explained up to 87% of variance in CD. CD explained up to 97% of variance in CCBF and CCBF/CBF.

CONCLUSION

PIT stimulates VEGF-mediated mobilization of EPCs as well as angiogenesis and might be proven as a new treatment strategy for patients with coronary heart disease.

Physical ischaemia induced by isometric exercise facilitated collateral development in the remote ischaemic myocardium of humans

Isometric-handgrip-exercise-induced local ischaemia in the normal limb facilitated collateral recruitment in acutely occluded vessels in patients with coronary artery disease. Ischaemic-handgrip-exercise-induced physical ischaemic training for 3 months facilitated myocardial collateral growth.