Low energy shock wave therapy induces angiogenesis in acute hind-limb ischemia via VEGF receptor 2 phosphorylation

Cardiac shockwave therapy in addition to coronary bypass surgery improves myocardial function in ischaemic heart failure: the CAST-HF trial

BACKGROUND AND AIMS

In chronic ischaemic heart failure, revascularisation strategies control symptoms but are less effective in improving left ventricular ejection fraction (LVEF). The aim of this trial is to investigate the safety of cardiac shockwave therapy (SWT) as a novel treatment option and its efficacy in increasing cardiac function by inducing angiogenesis and regeneration in hibernating myocardium.

METHODS

In this single-blind, parallel-group, sham-controlled trial (cardiac shockwave therapy for ischemic heart failure, CAST-HF; NCT03859466) patients with LVEF ≤40% requiring surgical revascularisation were enrolled. Patients were randomly assigned to undergo direct cardiac SWT or sham treatment in addition to coronary bypass surgery. The primary efficacy endpoint was the improvement in LVEF measured by cardiac magnetic resonance imaging from baseline to 360 days.

RESULTS

Overall, 63 patients were randomized, out of which 30 patients of the SWT group and 28 patients of the Sham group attained 1-year follow-up of the primary endpoint. Greater improvement in LVEF was observed in the SWT group (Δ from baseline to 360 days: SWT 11.3%, SD 8.8; Sham 6.3%, SD 7.4, P = .0146). Secondary endpoints included the 6-minute walking test, where patients randomized in the SWT group showed a greater Δ from baseline to 360 days (127.5 m, SD 110.6) than patients in the Sham group (43.6 m, SD 172.1) (P = .028) and Minnesota Living with Heart Failure Questionnaire score on day 360, which was 11.0 points (SD 19.1) for the SWT group and 17.3 points (SD 15.1) for the Sham group (P = .15). Two patients in the treatment group died for non-device-related reasons.

CONCLUSIONS

In conclusion, the CAST-HF trial indicates that direct cardiac SWT, in addition to coronary bypass surgery improves LVEF and physical capacity in patients with ischaemic heart failure.

Preadipocytes in human granulation tissue: role in wound healing and response to macrophage polarization

BACKGROUND

Chronic non-healing wounds pose a global health challenge. Under optimized conditions, skin wounds heal by the formation of scar tissue. However, deregulated cell activation leads to persistent inflammation and the formation of granulation tissue, a type of premature scar tissue without epithelialization. Regenerative cells from the wound periphery contribute to the healing process, but little is known about their cellular fate in an inflammatory, macrophage-dominated wound microenvironment.

METHODS

We examined CD45-/CD31-/CD34+ preadipocytes and CD68+ macrophages in human granulation tissue from pressure ulcers (n=6) using immunofluorescence, immunohistochemistry, and flow cytometry. In vitro, we studied macrophage-preadipocyte interactions using primary human adipose-derived stem cells (ASCs) exposed to conditioned medium harvested from IFNG/LPS (M1)- or IL4/IL13 (M2)-activated macrophages. Macrophages were derived from THP1 cells or CD14+ monocytes. In addition to confocal microscopy and flow cytometry, ASCs were analyzed for metabolic (OXPHOS, glycolysis), morphological (cytoskeleton), and mitochondrial (ATP production, membrane potential) changes. Angiogenic properties of ASCs were determined by HUVEC-based angiogenesis assay. Protein and mRNA levels were assessed by immunoblotting and quantitative RT-PCR.

RESULTS

CD45-/CD31-/CD34+ preadipocytes were observed with a prevalence of up to 1.5% of total viable cells in human granulation tissue. Immunofluorescence staining suggested a spatial proximity of these cells to CD68+ macrophages in vivo. In vitro, ASCs exposed to M1, but not to M2 macrophage secretome showed a pro-fibrotic response characterized by stress fiber formation, elevated alpha smooth muscle actin (SMA), and increased expression of integrins ITGA5 and ITGAV. Macrophage-secreted IL1B and TGFB1 mediated this response via the PI3K/AKT and p38-MAPK pathways. In addition, ASCs exposed to M1-inflammatory stress demonstrated reduced migration, switched to a glycolysis-dominated metabolism with reduced ATP production, and increased levels of inflammatory cytokines such as IL1B, IL8, and MCP1. Notably, M1 but not M2 macrophages enhanced the angiogenic potential of ASCs.

CONCLUSION

Preadipocyte fate in wound tissue is influenced by macrophage polarization. Pro-inflammatory M1 macrophages induce a pro-fibrotic response in ASCs through IL1B and TGFB1 signaling, while anti-inflammatory M2 macrophages have limited effects. These findings shed light on cellular interactions in chronic wounds and provide important information for the potential therapeutic use of ASCs in human wound healing.

Polydeoxyribonucleotide and Shock Wave Therapy Sequence Efficacy in Regenerating Immobilized Rabbit Calf Muscles

This study primarily aimed to investigate the combined effects of polydeoxyribonucleotide (PDRN) and extracorporeal shock wave therapy (ESWT) sequences on the regenerative processes in atrophied animal muscles. Thirty male New Zealand rabbits, aged 12 weeks, were divided into five groups: normal saline (Group 1), PDRN (Group 2), ESWT (Group 3), PDRN injection before ESWT (Group 4), and PDRN injection after ESWT (Group 5). After 2 weeks of cast immobilization, the respective treatments were administered to the atrophied calf muscles. Radial ESWT was performed twice weekly. Calf circumference, tibial nerve compound muscle action potential (CMAP), and gastrocnemius (GCM) muscle thickness after 2 weeks of treatment were evaluated. Histological and immunohistochemical staining, as well as Western blot analysis, were conducted 2 weeks post-treatment. Staining intensity and extent were assessed using semi-quantitative scores. Groups 4 and 5 demonstrated significantly greater calf muscle circumference, GCM muscle thickness, tibial nerve CMAP, and GCM muscle fiber cross-sectional area (type I, type II, and total) than the remaining three groups (p < 0.05), while they did not differ significantly in these parameters. Groups 2 and 3 showed higher values for all the mentioned parameters than Group 1 (p < 0.05). Group 4 had the greatest ratio of vascular endothelial growth factor (VEGF) to platelet endothelial cell adhesion molecule-1 (PECAM-1) in the GCM muscle fibers compared to the other four groups (p < 0.05). Western blot analysis revealed significantly higher expression of angiogenesis cytokines in Groups 4 and 5 than in the other groups (p < 0.05). The combination of ESWT and PDRN injection demonstrated superior regenerative efficacy for atrophied calf muscle tissue in rabbit models compared to these techniques alone or saline. In particular, administering ESWT after PDRN injection yielded the most favorable outcomes in specific parameters.

Low-Intensity Ultrasound Reduces Brain Infarct Size by Upregulating Phosphorylated Endothelial Nitric Oxide in Mouse Model of Middle Cerebral Artery Occlusion

OBJECTIVE

There have been attempts to use therapeutic ultrasound (US) for the treatment of both experimental and clinical stroke. We hypothesized that low-intensity US has direct beneficial effects on the brain independent of cerebral blood flow (CBF) during middle cerebral artery occlusion (MCAO).

METHODS

Three groups of mice were studied. Group I included 84 mice with MCAO undergoing US treatment/no treatment at two US frequencies (0.25 and 1.05 MHz) with three different acoustic pressures at each frequency in which infarct size (IS) was measured 24 h later. Group II included 11 mice undergoing treatment based on best US results from group I animals in which the IS/risk area (RA) ratio was measured 24 h later. Group III included 38 normal mice undergoing US treatment/no treatment for assessment of CBF, tissue metabolite and protein expression and histopathology.

DISCUSSION

Ultrasound at both frequencies and most acoustic pressures resulted in reduction in IS in group I animals, with the best results obtained with 0.25 MHz at 2.0 MPa: IS was reduced 4-fold in the cerebral cortex, 1.5-fold in the caudate putamen and 3.5-fold in the cerebral hemisphere compared with control. US application in group III animals elicited only a marginal increase in CBF despite a 2.6-fold increase in phosphorylated endothelial nitric oxide synthase (p-eNOS)-S1177 and a corresponding decrease in p-eNOS-T494. Histopathology revealed no evidence of hemorrhage, inflammation or necrosis.

CONCLUSION

Low-intensity US at specific frequencies and acoustic pressures results in marked neuroprotection in a mouse model of stroke by modulation of p-eNOS independent of its effect on CBF.

Low-Intensity Extracorporeal Shockwave Therapy (LI-ESWT) in Renal Diseases: A Review of Animal and Human Studies

Background

Low-intensity extracorporeal shockwave therapy (LI-ESWT) has been suggested as a treatment for vascular diseases such as ischemic heart disease, diabetic foot ulcers, and erectile dysfunction. Primarily, LI-ESWT is known for its ability to stimulate angiogenesis and activation of stem cells in target tissues. Application of LI-ESWT in chronic progressive renal diseases is a novel area. The aim of the present review was to summarize available data on the effects of LI-ESWT used in the setting of renal diseases.

Methods

We systematically searched PubMed, Medline, and Embase databases for relevant studies. Our review included the results from preclinical animal experiments and clinical research.

Results

Eleven animal studies and one clinical study were included in the review. In the animal studies, LI-ESWT was used for the treatment of hypertensive nephropathy (n=1), diabetic nephropathy (n=1), or various types of ischemic renal injury (ie, artery occlusion, reperfusion injury) (n=9). The clinical study was conducted in a single-arm cohort as a Phase 1 study with patients having diabetic nephropathy. In animal studies, the application of LI-ESWT was associated with several effects: LI-ESWT led to increased VEGF and endothelial cell proliferation and improved vascularity and perfusion of the kidney tissue. LI-ESWT reduced renal inflammation and fibrosis. LI-ESWT caused only mild side effects in the clinical study, and, similarly, there were no signs of kidney injury after LI-ESWT in the animal studies.

Conclusion

LI-ESWT, as a non-invasive treatment, reduces the pathological manifestations (inflammation, capillary rarefaction, fibrosis, decreased perfusion) associated with certain types of renal disease. The efficacy of renal LI-ESWT needs to be confirmed in randomized clinical trials.

Cardioprotective effects of shock wave therapy: A cardiac magnetic resonance imaging study on acute ischemia-reperfusion injury

Introduction

Cardioprotection strategies remain a new frontier in treating acute myocardial infarction (AMI), aiming at further protect the myocardium from the ischemia-reperfusion damage. Therefore, we aimed at investigating the mechano-transduction effects induced by shock waves (SW) therapy at time of the ischemia reperfusion as a non-invasive cardioprotective innovative approach to trigger healing molecular mechanisms.

Methods

We evaluated the SW therapy effects in an open-chest pig ischemia-reperfusion (IR) model, with quantitative cardiac Magnetic Resonance (MR) imaging performed along the experiments at multiple time points (baseline (B), during ischemia (I), at early reperfusion (ER) (∼15 min), and late reperfusion (LR) (3 h)). AMI was obtained by a left anterior artery temporary occlusion (50 min) in 18 pigs (32 ± 1.9 kg) randomized into SW therapy and control groups. In the SW therapy group, treatment was started at the end of the ischemia period and extended during early reperfusion (600 + 1,200 shots @0.09 J/mm2, f = 5 Hz). The MR protocol included at all time points LV global function assessment, regional strain quantification, native T1 and T2 parametric mapping. Then, after contrast injection (gadolinium), we obtained late gadolinium imaging and extra-cellular volume (ECV) mapping. Before animal sacrifice, Evans blue dye was administrated after re-occlusion for area-at-risk sizing.

Results

During ischemia, LVEF decreased in both groups (25 ± 4.8% in controls (p = 0.031), 31.6 ± 3.2% in SW (p = 0.02). After reperfusion, left ventricular ejection fraction (LVEF) remained significantly decreased in controls (39.9 ± 4% at LR vs. 60 ± 5% at baseline (p = 0.02). In the SW group, LVEF increased quickly ER (43.7 ± 11.4% vs. 52.4 ± 8.2%), and further improved at LR (49.4 ± 10.1) (ER vs. LR p = 0.05), close to baseline reference (LR vs. B p = 0.92). Furthermore, there was no significant difference in myocardial relaxation time (i.e. edema) after reperfusion in the intervention group compared to the control group: ΔT1 (MI vs. remote) was increased by 23.2±% for SW vs. +25.2% for the controls, while ΔT2 (MI vs. remote) increased by +24.9% for SW vs. +21.7% for the control group.

Discussion

In conclusion, we showed in an ischemia-reperfusion open-chest swine model that SW therapy, when applied near the relief of 50' LAD occlusion, led to a nearly immediate cardioprotective effect translating to a reduction in the acute ischemia-reperfusion lesion size and to a significant LV function improvement. These new and promising results related to the multi-targeted effects of SW therapy in IR injury need to be confirmed by further in-vivo studies in close chest models with longitudinal follow-up.

The association of catestatin and endocan with the effects of cardiac shock wave therapy: Biomarker sub-study of the randomized, sham procedure-controlled trial

Introduction

Cardiac shock-wave therapy (CSWT) is a non-invasive regenerative treatment method based on low-frequency ultrasound waves, which stimulate angiogenesis. Current data about the effects of revascularization procedures on angiogenesis biomarkers is limited. Recently, an association of catestatin and endocan with coronary collateral development was shown in several trials. In this study, we aimed to evaluate the impact of CSWT on the dynamics of catestatin and endocan levels and to assess their correlation with parameters of myocardial perfusion and function.

Methods

Prospective, randomized, triple-blind, sham procedure-controlled study enrolled 72 adult subjects who complied with defined inclusion criteria (NCT02339454). We measured biomarkers in 48 patients with stable angina (24 patients of CSWT group, 24 patients of sham-procedure group). Additionally, patients were divided into responders and non-responders according to improvement in myocardial perfusion and/or contractility assessed by myocardial scintigraphy and dobutamine echocardiography (30 and 13 patients, respectively). The blood samples were collected at baseline, after the last treatment procedure (9th treatment week) and at 6-month follow-up to evaluate biomarkers concentration and stored at -80° until analysis. Serum catestatin and endocan levels were determined by commercially available ELISA kits.

Results

Serum catestatin concentration significantly increased in all patients. While endocan levels significantly decreased in the responders sub-group. The increase in catestatin levels at 9th week and 6 months was positively associated with improvement in summed difference score (rho = 0.356, p = 0.028) and wall motion score, WMS (rho = 0.397, p = 0.009) at 6 months in the whole study population. Meanwhile, the decrease in endocan levels over 6 months was positively correlated with improvement in WMS at 3- and 6- months (r = 0.378, p = 0.015 and r = 0.311, p = 0.045, respectively). ROC analysis revealed that a change at 6 months in catestatin and endocan levels significantly predicted improvement in myocardial perfusion and contractile function with 68.9% sensitivity and 75.0% specificity (p = 0.039) and 51.7% sensitivity, and 91.7% specificity (p = 0.017), respectively. Baseline endocan concentration and its change at 6 months predicted response to CSWT with 68.8% sensitivity and 83.3% specificity (p = 0.039) and 81.3% sensitivity and 100% specificity (p < 0.0001), respectively.

Conclusion

This study demonstrates the association of increase in catestatin and decrease in endocan levels with the improvement of myocardial perfusion and contractile function. The potential predictive value of catestatin and endocan dynamics for the response to regenerative therapy is shown.

Prevention of Oxidative Damage in Spinal Cord Ischemia Upon Aortic Surgery: First-In-Human Results of Shock Wave Therapy Prove Safety and Feasibility

Background Spinal cord ischemia (SCI) remains a devastating complication after aortic dissection or repair. A primary hypoxic damage is followed by a secondary damage resulting in further cellular loss via apoptosis. Affected patients have a poor prognosis and limited therapeutic options. Shock wave therapy (SWT) improves functional outcome, neuronal degeneration and survival in murine spinal cord injury. In this first-in-human study we treated 5 patients with spinal cord ischemia with SWT aiming to prove safety and feasibility. Methods and Results Human neurons were subjected to ischemic injury with subsequent SWT. Reactive oxygen species and cellular apoptosis were quantified using flow cytometry. Signaling of the antioxidative transcription factor NRF2 (nuclear factor erythroid 2-related factor 2) and immune receptor Toll-like receptor 3 (TLR3) were analyzed. To assess whether SWT act via a conserved mechanism, transgenic tlr3^-/- zebrafish created via CRISPR/Cas9 were subjected to spinal cord injury. To translate our findings into a clinical setting, 5 patients with SCI underwent SWT. Baseline analysis and follow-up (6 months) included assessment of American Spinal Cord Injury Association (ASIA) impairment scale, evaluation of Spinal Cord Independence Measure score and World Health Organization Quality of Life questionnaire. SWT reduced the number of reactive oxygen species positive cells and apoptosis upon ischemia via induction of the antioxidative factor nuclear factor erythroid 2-related factor 2. Inhibition or deletion of tlr3 impaired axonal growth after spinal cord lesion in zebrafish, whereas tlr3 stimulation enhanced spinal regeneration. In a first-in-human study, we treated 5 patients with SCI using SWT (mean age, 65.3 years). Four patients presented with acute aortic dissection (80%), 2 of them exhibited preoperative neurological symptoms (40%). Impairment was ASIA A in 1 patient (20%), ASIA B in 3 patients (60%), and ASIA D in 1 patient (20%) at baseline. At follow-up, 2 patients were graded as ASIA A (40%) and 3 patients as ASIA B (60%). Spinal cord independence measure score showed significant improvement. Examination of World Health Organization Quality of Life questionnaires revealed increased scores at follow-up. Conclusions SWT reduces oxidative damage upon SCI via immune receptor TLR3. The first-in-human application proved safety and feasibility in patients with SCI. SWT could therefore become a powerful regenerative treatment option for this devastating injury.

A narrative review on the application of high-intensity focused ultrasound for the treatment of occlusive and thrombotic arterial disease

Objectives

High-intensity focused ultrasound (HIFU) is a noninvasive therapeutic modality with a variety of applications. It is approved for the treatment of essential tremors, ablation of prostate, hepatic, breast, and uterine tumors. Although not approved for use in the treatment of atherosclerotic arterial disease, there is a growing body of evidence investigating applications of HIFU. Currently, percutaneous endovascular techniques are predominant for the treatment of arterial pathology; however, there are no endovascular techniques of HIFU available. This study aims to review the state of current evidence for the application of HIFU in atherosclerotic arterial disease.

Methods

All English-language articles evaluating the effect of HIFU on arterial occlusive and thrombotic disease until 2021 were reviewed. Both preclinical and human clinical studies were included. Study parameters such as animal or clinical model and outcomes were reviewed. In addition, details pertaining to settings on the HIFU device used were also reviewed.

Results

In preclinical models, atherosclerotic plaque progression was inhibited by HIFU, through decreases in oxidized low-density lipoprotein cholesterol and increases in macrophage apoptosis. Additionally, HIFU promotes angiogenesis in hindlimb ischemic models by the upregulation of angiogenic and antiapoptotic factors, with increased angiogenesis at higher line densities of HIFU. HIFU also promotes thrombolysis and conversely induces platelet activation at low frequencies and higher intensities. Various clinical studies have attempted to translate some of these properties and demonstrated positive clinical outcomes for arterial recanalization after thrombotic stroke, decreased atherosclerotic plaque burden in carotid arteries, increase in tissue perfusion and a decrease in diameter stenosis in patients with atherosclerotic arterial disease.

Conclusions

In current preclinical and clinical data, the safety and efficacy of HIFU shows great promise in the treatment of atherosclerotic arterial disease. Future focused studies are warranted to guide the refinement of HIFU settings for more widespread adoption of this technology.

Cardiac Shockwave Therapy – A Novel Therapy for Ischemic Cardiomyopathy?

Over the past decades, shockwave therapy (SWT) has gained increasing interest as a therapeutic approach for regenerative medicine applications, such as healing of bone fractures and wounds. More recently, pre-clinical studies have elucidated potential mechanisms for the regenerative effects of SWT in myocardial ischemia. The mechanical stimulus of SWT may induce regenerative effects in ischemic tissue via growth factor release, modulation of inflammatory response, and angiogenesis. Activation of the innate immune system and stimulation of purinergic receptors by SWT appears to enhance vascularization and regeneration of injured tissue with functional improvement. Intriguingly, small single center studies suggest that SWT may improve angina, exercise tolerance, and hemodynamics in patients with ischemic heart disease. Thus, SWT may represent a promising technology to induce cardiac protection or repair in patients with ischemic heart disease.

The effect of extracorporeal shock wave therapy in acute traumatic spinal cord injury on motor and sensory function within 6 months post-injury: a study protocol for a two-arm three-stage adaptive, prospective, multi-center, randomized, blinded, placebo-controlled clinical trial

Background

The pathological mechanism in acute spinal cord injury (SCI) is dual sequential: the primary mechanical lesion and the secondary injury due to a cascade of biochemical and pathological changes initiated by the primary lesion. Therapeutic approaches have focused on modulating the mechanisms of secondary injury. Despite extensive efforts in the treatment of SCI, there is yet no causal, curative treatment approach available.

Extracorporeal shock wave therapy (ESWT) has been successfully implemented in clinical use. Biological responses to therapeutic shock waves include altered metabolic activity of various cell types due to direct and indirect mechanotransduction leading to improved migration, proliferation, chemotaxis, modulation of the inflammatory response, angiogenesis, and neovascularization, thus inducing rather a regeneration than repair.

The aim of this clinical study is to investigate the effect of ESWT in humans within the first 48 h after an acute traumatic SCI, with the objective to intervene in the secondary injury phase in order to reduce the extent of neuronal loss.

Methods

This two-arm three-stage adaptive, prospective, multi-center, randomized, blinded, placebo-controlled study has been initiated in July 2020, and a total of 82 patients with acute traumatic SCI will be recruited for the first stage in 15 participating hospitals as part of a two-armed three-stage adaptive trial design. The focused ESWT (energy flux density: 0.1–0.19 mJ/mm², frequency: 2–5 Hz) is applied once at the level of the lesion, five segments above/below, and on the plantar surface of both feet within the first 48 h after trauma.

The degree of improvement in motor and sensory function after 6 months post-injury is the primary endpoint of the study. Secondary endpoints include routine blood chemistry parameters, the degree of spasticity, the ability to walk, urological function, quality of life, and the independence in everyday life.

Discussion

The application of ESWT activates the nervous tissue regeneration involving a multitude of various biochemical and cellular events and leads to a decreased neuronal loss. ESWT might contribute to an improvement in the treatment of acute traumatic SCI in future clinical use.

Trial registration

ClinicalTrials.govNCT04474106

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06161-8.

Combined extracorporeal shockwave therapy and exercise for the treatment of tendinopathy: A narrative review

Tendinopathy is a chronic degenerative musculoskeletal disorder that is common in both athletes and the general population. Exercise and extracorporeal shockwave therapy (ESWT) is among the most common treatments used to mediate tendon healing and regeneration. The review presents the current understanding of mechanisms of action of ESWT and exercise in isolation and briefly synthesises evidence of their effectiveness for various tendinopathies. The central purpose of the review is to synthesize research findings investigating the combination of ESWT and exercise for five common tendinopathies (plantar heel pain, rotator cuff, lateral elbow, Achilles, and patellar tendinopathy) and provide recommendations on clinical applicability. Collectively, the available evidence indicates that ESWT combined with exercise in the form of eccentric training, tissue-specific stretching, or heavy slow resistance training are effective for specific tendinopathies and can therefore be recommended in treatment. Whilst there are at present a limited number of studies investigating combined EWST and exercise approaches, there is evidence to suggest that the combination improves outcomes in the treatment of plantar heel pain, Achilles, lateral elbow, and rotator cuff tendinopathy. However, despite overall positive outcomes in patellar tendinopathy, the combined treatment has not been shown at present to offer additional benefit over eccentric exercise alone.

New Treatment Option for Clinical and Subclinical Mastitis in Dairy Cows Using Acoustic Pulse Technology (APT)

The effect of acoustic pulse technology (APT) on recovery, culling, milk yield, and economic benefits for 118 cows with subclinical mastitis was compared with a no-treatment control (59 vs. 59), and another 118 APT-treated cows with clinical mastitis were compared with antibiotic-treated controls (59 vs. 59). Recovery was defined as a decrease in somatic cell count (SCC) to <250 × 103 cells/mL in at least two out of three monthly milk recordings after treatments. For the subclinically infected cows, APT treatment resulted in 65.5% recovery, 0% culling, and additional milk yield of 2.74 L/cow per day compared to 35.6% recovery and 5.1% culling in the no-treatment controls. For the clinically infected cows, APT treatment resulted in 67.8% recovery, 6.8% culling, and additional milk yield of 3.9 L/cow per day compared to 35.6% recovery and 32.2% culling in the antibiotic-treated group. Bacteriological analysis was run for 95 (80%) cows with clinical mastitis (APT-46; AB-49). For cows with Escherichia coli infection, 85.7% (18/21) treated with APT recovered vs. 17.6% (3/17) in the antibiotic-treated group; for cows with streptococcal infection, 66.0% (12/18) in the APT-treated group recovered vs. 44.4% (8/18) in the antibiotic-treated group.

Efficacy of penile low-intensity shockwave treatment for erectile dysfunction: correlation with the severity of cavernous artery disease

We analyzed the efficacy of penile low-intensity extracorporeal shockwave treatment for erectile dysfunction (ED) combined with cavernous artery disease (CAD). ED was evaluated by the International Index of Erectile Function, subdividing patients into mild and moderate/severe forms. CAD was assessed using penile color Doppler ultrasonography. Patients (n = 111) with a positive outcome after treatment, based upon the minimal clinically important difference of the International Index of ED, were followed up for 3 months and 6 months. We found a significant mean increase in the index of erectile function, with an overall improvement in hemodynamic parameters of the cavernous artery. In particular, 93.9% of the patients with mild ED without CAD responded to treatment and 72.7% resumed normal erectile function. Only 31.2% of the patients with moderate/severe ED and CAD responded to treatment, and none resumed normal erectile function. All patients with mild ED and no CAD maintained the effects of therapy after 3 months, while no patients with moderate/severe ED and CAD maintained the benefits of treatment after 3 months. Thus, patients with mild ED and no CAD have better and longer lasting responses to such treatment, with a higher probability of resuming normal erectile function than patients with moderate/severe ED and CAD.

Normoxic low-altitude simulation (at 714 mmHg) improves limb blood perfusion in mice with hindlimb ischemia

Humans have fewer cardiovascular events and improved outcomes after cardiovascular events when living at low and moderate altitudes (<3000 m) above sea level. We have previously shown that low‐altitude simulation using reductions in barometric pressure enhances vasodilation ex vivo in arterial segments and reduces systemic vascular resistance in vivo and can also improve left ventricular function after a myocardial infarction. We hypothesize that low‐altitude simulation could also improve hindlimb ischemia, a model of peripheral artery disease in humans. We performed femoral artery ligation to generate hindlimb ischemia in 3‐month‐old C57BL6 mice. Control group mice (n = 10) recovered at 754 mmHg (control) for 14 days. Treatment group mice (n = 15) were placed in a low‐altitude simulation chamber (at 714 mmHg) to recover from surgery for 3‐hours daily for 14 days. Hindlimb perfusion imaging using a laser Doppler line scanner was performed for all mice prior to the surgery, and then on days 1, 3, 7, and 14 post‐surgery. At 2 weeks, ischemic reserve was significantly higher in the treatment group mice (0.50 ± 0.13 vs. 0.20 ± 0.06; p = 0.01). Treatment mice had higher functional scores and were able to walk better at two weeks. There was approximately three times less HIF1α found via western blotting and a small but statistically significant improvement of lectin perfusion in calf tissue of treatment mice. We conclude that low‐altitude simulation improves blood perfusion in murine hindlimb ischemia. This approach may have therapeutic implications for humans with peripheral artery disease.

Defining a therapeutic range for regeneration of ischemic myocardium via shock waves

Shockwave therapy (SWT) represents a promising regenerative treatment option for patients with ischemic cardiomyopathy. Although no side-effects have been described upon SWT, potential cellular damage at therapeutic energies has not been addressed so far. In this work, we aimed to define a therapeutic range for shock wave application for myocardial regeneration. We could demonstrate that SWT does not induce cellular damage beneath energy levels of 0.27 mJ/mm² total flux density. Endothelial cell proliferation, angiogenic gene expression and phosphorylation of AKT and ERK are enhanced in a dose dependent manner until 0.15 mJ/mm² energy flux density. SWT induces regeneration of ischemic muscle in vivo via expression of angiogenic gene expression, enhanced neovascularization and improved limb perfusion in a dose-dependent manner. Therefore, we provide evidence for a dose-dependent induction of angiogenesis after SWT, as well as the absence of cellular damage upon SWT within the therapeutic range. These data define for the first time a therapeutic range of SWT, a promising regenerative treatment option for ischemic cardiomyopathy.

Shock waves promote spinal cord repair via TLR3

Spinal cord injury (SCI) remains a devastating condition with poor prognosis and very limited treatment options. Affected patients are severely restricted in their daily activities. Shock wave therapy (SWT) has shown potent regenerative properties in bone fractures, wounds, and ischemic myocardium via activation of the innate immune receptor TLR3. Here, we report on the efficacy of SWT for regeneration of SCI. SWT improved motor function and decreased lesion size in WT but not Tlr3-/- mice via inhibition of neuronal degeneration and IL6-dependent recruitment and differentiation of neuronal progenitor cells. Both SWT and TLR3 stimulation enhanced neuronal sprouting and improved neuronal survival, even in human spinal cord cultures. We identified tlr3 as crucial enhancer of spinal cord regeneration in zebrafish. Our findings indicate that TLR3 signaling is involved in neuroprotection and spinal cord repair and suggest that TLR3 stimulation via SWT could become a potent regenerative treatment option.

Safety and efficacy of direct Cardiac Shockwave Therapy in patients with ischemic cardiomyopathy undergoing coronary artery bypass grafting (the CAST-HF trial): study protocol for a randomized controlled trial

BACKGROUND

Coronary artery diseases (CAD) remains a severe socio-economic burden in the Western world. Coronary obstruction and subsequent myocardial ischemia result in progressive replacement of contractile myocardium with dysfunctional, fibrotic scar tissue. Post-infarctional remodeling is causal for the concomitant decline of left-ventricular function and the fatal syndrome of heart failure. Available neurohumoral treatment strategies aim at the improvement of symptoms. Despite extensive research, therapeutic options for myocardial regeneration, including (stem)-cell therapy, gene therapy, cellular reprogramming or tissue engineering, remain purely experimental. Thus, there is an urgent clinical need for novel treatment options for inducing myocardial regeneration and improving left-ventricular function in ischemic cardiomyopathy. Shockwave Therapy (SWT) is a well-established regenerative tool that is effective for the treatment of chronic tendonitis, long-bone non-union and wound-healing disorders. In preclinical trials, SWT regenerated ischemic myocardium via the induction of angiogenesis and the reduction of fibrotic scar tissue, resulting in improved left-ventricular function.

METHODS/DESIGN

In this prospective, randomized controlled, single-blind, monocentric study, 80 patients with reduced left-ventricular ejection fraction (LVEF≤ 40%) are subjected to coronary-artery bypass-graft surgery (CABG) surgery and randomized in a 1:1 ratio to receive additional cardiac SWT (intervention group; 40 patients) or CABG surgery with sham treatment (control group; 40 patients). This study aims to evaluate (1) the safety and (2) the efficacy of cardiac SWT as adjunctive treatment during CABG surgery for the regeneration of ischemic myocardium. The primary endpoints of the study represent (1) major cardiac events and (2) changes in left-ventricular function 12 months after treatment. Secondary endpoints include 6-min Walk Test distance, improvement of symptoms and assessment of quality of life.

DISCUSSION

This study aims to investigate the safety and efficacy of cardiac SWT during CABG surgery for myocardial regeneration. The induction of angiogenesis, decrease of fibrotic scar tissue formation and, thus, improvement of left-ventricular function could lead to improved quality of life and prognosis for patients with ischemic heart failure. Thus, it could become the first clinically available treatment strategy for the regeneration of ischemic myocardium alleviating the socio-economic burden of heart failure.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03859466. Registered on 1 March 2019.

The Basic Science Behind Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction: A Systematic Scoping Review of Pre-Clinical Studies

INTRODUCTION

Despite recent promising clinical results, the underlying mechanism of action of low-intensity extracorporeal shockwave therapy (Li-ESWT) for erectile dysfunction (ED) is mostly unclear and currently under investigation.

AIM

To systematically identify and evaluate evidence regarding the basic science behind Li-ESWT for ED, discuss and propose a putative mechanism of action, address the limitations, and imply insights for further investigation in the field.

METHODS

Using Cochrane's methodologic recommendations on scoping studies and systematic reviews, we conducted a systematic scoping review of the literature on experimental research regarding Li-ESWT for ED and other pathologic conditions. The initial systematic search was carried between January and November 2017, with 2 additional searches in April and August 2018. All studies that applied shockwave treatment at an energy flux density >0.25 mJ/mm² were excluded from the final analysis.

MAIN OUTCOME MEASURE

We primarily aimed to clarify the biological responses in erectile tissue after Li-ESWT that could lead to improvement in erectile function.

RESULTS

59 publications were selected for inclusion in this study. 15 experimental research articles were identified on Li-ESWT for ED and 44 on Li-ESWT for other pathologic conditions. Li-ESWT for ED seems to improve erectile function possibly through stimulation of mechanosensors, inducing the activation of neoangiogenesis processes, recruitment and activation of progenitor cells, improving microcirculation, nerve regeneration, remodeling of erectile tissue, and reducing inflammatory and cellular stress responses.

CLINICAL IMPLICATIONS

Improving our understanding of the mechanism of action of Li-ESWT for ED can help us improve our study designs, as well as suggest new avenues of investigation.

STRENGTHS & LIMITATIONS

A common limitation in all these studies is the heterogeneity of the shockwave treatment application and protocol.

CONCLUSION

Li-ESWT for ED, based on current experimental studies, seems to improve erectile function by inducing angiogenesis and reversing pathologic processes in erectile tissue. These studies provide preliminary insights, but no definitive answers, and many questions remain unanswered regarding the mechanism of action, as well as the ideal treatment protocol. Sokolakis I, Dimitriadis F, Teo P, et al. The Basic Science Behind Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction: A Systematic Scoping Review of Pre-Clinical Studies. J Sex Med 2019;16:168-194.

Shock Wave Therapy Improves Cardiac Function in a Model of Chronic Ischemic Heart Failure: Evidence for a Mechanism Involving VEGF Signaling and the Extracellular Matrix

Background

Mechanical stimulation of acute ischemic myocardium by shock wave therapy (SWT) is known to improve cardiac function by induction of angiogenesis. However, SWT in chronic heart failure is poorly understood. We aimed to study whether mechanical stimulation upon SWT improves heart function in chronic ischemic heart failure by induction of angiogenesis and postnatal vasculogenesis and to dissect underlying mechanisms.

Methods and Results

SWT was applied in a mouse model of chronic myocardial ischemia. To study effects of SWT on postnatal vasculogenesis, wild‐type mice received bone marrow transplantation from green fluorescence protein donor mice. Underlying mechanisms were elucidated in vitro in endothelial cells and murine aortic rings. Echocardiography and pressure/volume measurements revealed improved left ventricular ejection fraction, myocardial contractility, and diastolic function and decreased myocardial fibrosis after treatment. Concomitantly, numbers of capillaries and arterioles were increased. SWT resulted in enhanced expression of the chemoattractant stromal cell–derived factor 1 in ischemic myocardium and serum. Treatment induced recruitment of bone marrow–derived endothelial cells to the site of injury. In vitro, SWT resulted in endothelial cell proliferation, enhanced survival, and capillary sprouting. The effects were vascular endothelial growth factor receptor 2 and heparan sulfate proteoglycan dependent.

Conclusions

SWT positively affects heart function in chronic ischemic heart failure by induction of angiogenesis and postnatal vasculogenesis. SWT upregulated pivotal angiogenic and vasculogenic factors in the myocardium in vivo and induced proliferative and anti‐apoptotic effects on endothelial cells in vitro. Mechanistically, these effects depend on vascular endothelial growth factor signaling and heparan sulfate proteoglycans. SWT is a promising treatment option for regeneration of ischemic myocardium.

Physical energies to the rescue of damaged tissues

Rhythmic oscillatory patterns sustain cellular dynamics, driving the concerted action of regulatory molecules, microtubules, and molecular motors. We describe cellular microtubules as oscillators capable of synchronization and swarming, generating mechanical and electric patterns that impact biomolecular recognition. We consider the biological relevance of seeing the inside of cells populated by a network of molecules that behave as bioelectronic circuits and chromophores. We discuss the novel perspectives disclosed by mechanobiology, bioelectromagnetism, and photobiomodulation, both in term of fundamental basic science and in light of the biomedical implication of using physical energies to govern (stem) cell fate. We focus on the feasibility of exploiting atomic force microscopy and hyperspectral imaging to detect signatures of nanomotions and electromagnetic radiation (light), respectively, generated by the stem cells across the specification of their multilineage repertoire. The chance is reported of using these signatures and the diffusive features of physical waves to direct specifically the differentiation program of stem cells in situ, where they already are resident in all the tissues of the human body. We discuss how this strategy may pave the way to a regenerative and precision medicine without the needs for (stem) cell or tissue transplantation. We describe a novel paradigm based upon boosting our inherent ability for self-healing.

Low-energy shock waves evoke intracellular Ca2+ increases independently of sonoporation

Low-energy shock waves (LESWs) accelerate the healing of a broad range of tissue injuries, including angiogenesis and bone fractures. In cells, LESW irradiations enhance gene expression and protein synthesis. One probable mechanism underlying the enhancements is mechanosensing. Shock waves also can induce sonoporation. Thus, sonoporation is another probable mechanism underlying the enhancements. It remains elusive whether LESWs require sonoporation to evoke cellular responses. An intracellular Ca²⁺ increase was evoked with LESW irradiations in endothelial cells. The minimum acoustic energy required for sufficient evocation was 1.7 μJ/mm². With the same acoustic energy, sonoporation, by which calcein and propidium iodide would become permeated, was not observed. It was found that intracellular Ca²⁺ increases evoked by LESW irradiations do not require sonoporation. In the intracellular Ca²⁺ increase, actin cytoskeletons and stretch-activated Ca²⁺ channels were involved; however, microtubules were not. In addition, with Ca²⁺ influx through the Ca²⁺ channels, the Ca²⁺ release through the PLC-IP₃-IP₃R cascade contributed to the intracellular Ca²⁺ increase. These results demonstrate that LESW irradiations can evoke cellular responses independently of sonoporation. Rather, LESW irradiations evoke cellular responses through mechanosensing.

Cellular signaling pathways modulated by low-intensity extracorporeal shock wave therapy

Low-intensity extracorporeal shock wave therapy (Li-ESWT) is a form of energy transfer that is of lower intensity (<0.2mJ/mm²) relative to traditional Extracorporeal Shock Wave Lithotripsy (ESWL) used for management of urinary stones. At this intensity and at appropriate dosing energy transfer is thought to induce beneficial effects in human tissues. The proposed therapeutic mechanisms of action for Li-ESWT include neovascularization, tissue regeneration, and reduction of inflammation. These effects are thought to be mediated by enhanced expression of vascular endothelial growth factor, endothelial nitric oxide synthase, and proliferating cell nuclear antigen. Upregulation of chemoattractant factors and recruitment/activation of stem/progenitor cells may also play a role. Li-ESWT has been studied for management of musculoskeletal disease, ischemic cardiovascular disorders, Peyronie's Disease, and more recently erectile dysfunction (ED). The underlying mechanism of Li-ESWT for treatment of ED is incompletely understood. We summarize the current evidence basis by which Li-ESWT is thought to enhance penile hemodynamics with an intention of outlining the fundamental mechanisms by which this therapy may help manage ED.

Stimulation of angiogenesis using single-pulse low-pressure shock wave treatment

Endothelial cells respond to mechanical stimuli such as stretch. This property can be exploited with caution to induce angiogenesis which will have immense potential to treat pathological conditions associated with insufficient angiogenesis. The primary aim of this study is to test if low-pressure shock waves can be used to induce angiogenesis. Using a simple diaphragm-based shock tube, we demonstrate that a single pulse of low pressure (0.4 bar) shock wave is enough to induce proliferation in bovine aortic endothelial cells and human pulmonary microvascular endothelial cells. We show that this is associated with enhanced Ca⁺⁺ influx and phosphorylation of phosphatidylinositol-3-kinase (PI3K) which is normally observed when endothelial cells are exposed to stretch. We also demonstrate the pro-angiogenic effect of shock waves of single pulse (per dose) using murine back punch wound model. Shock wave treated mice showed enhanced wound-induced angiogenesis as reflected by increased vascular area and vessel length. They also showed accelerated wound closure compared to control mice. Overall, our study shows that just a single pulse/shot (per dose) of shock waves can be used to induce angiogenesis. Importantly, we demonstrate this effect using a pulse of low-pressure shock waves (0.4 bar, in vitro and 0.15 bar, in vivo). KEY MESSAGES: Low-pressure single-pulse shock waves can induce endothelial cell migration and proliferation. This effect is endothelial cell specific. These shock waves enhance wound-induced angiogenesis in vivo. These shock waves can also accelerate wound healing in vivo.

Unfocused shockwaves for osteoinduction in bone substitutes in rat cortical bone defects

Bone substitutes are frequently used in clinical practice but often exhibit limited osteoinductivity. We hypothesized that unfocused shockwaves enhance the osteoinductivity of bone substitutes and improve osteointegration and angiogenesis. Three different bone substitutes, namely porous tricalcium phosphate, porous hydroxyapatite and porous titanium alloy, were implanted in a critical size (i.e. 6-mm) femoral defect in rats. The femora were treated twice with 1500 shockwaves at 2 and 4 weeks after surgery and compared with non-treated controls. The net volume of de novo bone in the defect was measured by microCT-scanning during 11-weeks follow-up. Bone ingrowth and angiogenesis in the bone substitutes was examined at 5 and 11 weeks using histology. It was shown that hydroxyapatite and titanium both had an increase of bone ingrowth with more bone in the shockwave group compared to the control group, whereas resorption was seen in tricalcium phosphate bone substitutes over time and this was insensitive to shockwave treatment. In conclusion, hydroxyapatite and titanium bone substitutes favour from shockwave treatment, whereas tricalcium phosphate does not. This study shows that osteoinduction and osteointegration of bone substitutes can be influenced with unfocused shockwave therapy, but among other factors depend on the type of bone substitute, likely reflecting its mechanical and biological properties.

Extracorporeal shockwave therapy for intermittent claudication: Medium-term outcomes from a double-blind randomised placebo-controlled pilot trial

Objectives Peripheral arterial disease most commonly presents as intermittent claudication (IC). Early evidence has suggested that extracorporeal shockwave therapy is efficacious in the short term for the management of intermittent claudication. The objective of this pilot trial was to evaluate the medium-term efficacy of this treatment. Methods This double-blind randomised placebo-controlled pilot trial randomised patients with unilateral intermittent claudication in a 1:1 fashion to receive extracorporeal shockwave therapy or a sham treatment for three sessions per week over three weeks. Primary outcomes were maximum walking distance and intermittent claudication distance using a fixed-load treadmill test. Secondary outcomes included pre- and post-exertional ankle-brachial pressure indices, safety and quality of life assessed using generic (SF36, EQ-5D-3L) and disease-specific (vascular quality of life) measures. All outcome measures were assessed at 12 months post-treatment. Results Thirty participants were included in the study (extracorporeal shockwave therapy, n = 15; sham, n = 15), with 26 followed up and analysed at 12 months (extracorporeal shockwave therapy, n = 13; sham, n = 13). Intragroup analysis demonstrated significant improvements in maximum walking distance, intermittent claudication distance and post-exertional ankle-brachial pressure indices ( p < 0.05) in the active treatment group, with no improvements in pre-exertional ankle-brachial pressure indices. Significant improvements in quality of life were observed in 3 out of 19 domains assessed in the active group. A re-intervention rate of 26.7% was seen in both groups. Conclusions These findings suggest that extracorporeal shockwave therapy is effective in improving walking distances at 12 months. Although this study provides important pilot data, a larger study is needed to corroborate these findings and to investigate the actions of this treatment.

ISRCTN

NCT02652078.

Extracorporeal Shock Wave Therapy in Acute Injury Care: A Systematic Review

Objectives:

We provide a systematic review of the literature to identify clinical studies assessing the effects of extracorporeal shock wave therapy (ESWT) on acutely injured tissues of human subjects, also highlighting the biological mechanisms by which the technique is proposed to promote the processes of early tissue repair. Special attention is also paid to the progress of research in animal models.

Method:

A systematic review of the literature on ESWT of acute injuries of bone and soft tissue as available in the PubMed/MEDLINE, Cochrane CENTRAL, SPORTDiscus, and CINAHL databases up to December 2017 was conducted.

Results:

A total of 10 studies were included. There is some evidence for the application of ESWT in an early postacute injury phase. Most studies report benefits with no or minimal side effects. However, different types of treated tissues and wounds (varying cause and severity) and resulting heterogeneity in study design and outcome measurement make it difficult to compare studies. The picture of knowledge remains limited by an apparent lack of data on optimal treatment timing and on tissue- and injury-specific parameters.

Conclusions:

Although the amount of studies to date is still limited, recent clinical research has presented first successful steps to introduce ESWT as a means of treatment in acute injury care. Therefore, on the basis of the analyzed data, further testing is encouraged to validate optimal timing, physical settings, and possible long-term effects to exclude potential risks.

Low-energy shock wave preconditioning reduces renal ischemic reperfusion injury caused by renal artery occlusion

Purpose:

To evaluate whether low energy shock wave preconditioning could reduce renal ischemic reperfusion injury caused by renal artery occlusion.

Methods:

The right kidneys of 64 male Sprague Dawley rats were removed to establish an isolated kidney model. The rats were then divided into four treatment groups: Group 1 was the sham treatment group; Group 2, received only low-energy (12 kv, 1 Hz, 200 times) shock wave preconditioning; Group 3 received the same low-energy shock wave preconditioning as Group 2, and then the left renal artery was occluded for 45 minutes; and Group 4 had the left renal artery occluded for 45 minutes. At 24 hours and one-week time points after reperfusion, serum inducible nitric oxide synthase (iNOS), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), creatinine (Cr), and cystatin C (Cys C) levels were measured, malondialdehyde (MDA) in kidney tissue was detected, and changes in nephric morphology were evaluated by light and electron microscopy.

Results:

Twenty-four hours after reperfusion, serum iNOS, NGAL, Cr, Cys C, and MDA levels in Group 3 were significantly lower than those in Group 4; light and electron microscopy showed that the renal tissue injury in Group 3 was significantly lighter than that in Group 4. One week after reperfusion, serum NGAL, KIM-1, and Cys C levels in Group 3 were significantly lower than those in Group 4.

Conclusion:

Low-energy shock wave preconditioning can reduce renal ischemic reperfusion injury caused by renal artery occlusion in an isolated kidney rat model.

Extracorporeal shock wave therapy in situ - novel approach to obtain an activated fat graft

One of the mainstays of facial rejuvenation strategies is volume restoration, which can be achieved by autologous fat grafting. In our novel approach, we treated the adipose tissue harvest site with extracorporeal shock wave therapy (ESWT) in order to improve the quality of the regenerative cells in situ. The latter was demonstrated by characterizing the cells of the stromal vascular fraction (SVF) in the harvested liposuction material regarding cell yield, adenosine triphosphate (ATP) content, proliferative capacity, surface marker profile, differentiation potential and secretory protein profile. Although the SVF cell yield was only slightly enhanced, viability and ATP concentration of freshly isolated cells as well as proliferation doublings after 3 weeks in culture were significantly increased in the ESWT compared with the untreated group. Likewise, cells expressing mesenchymal and endothelial/pericytic markers were significantly elevated concomitant with an improved differentiation capacity towards the adipogenic lineage and enhancement in specific angiogenic proteins. Hence, in situ ESWT might be applied in the future to promote cell fitness, adipogenesis and angiogenesis within the fat graft for successful facial rejuvenation strategies with potential long-term graft survival.

Improvement of adipose tissue-derived cells by low-energy extracorporeal shock wave therapy

BACKGROUND

Cell-based therapies with autologous adipose tissue-derived cells have shown great potential in several clinical studies in the last decades. The majority of these studies have been using the stromal vascular fraction (SVF), a heterogeneous mixture of fibroblasts, lymphocytes, monocytes/macrophages, endothelial cells, endothelial progenitor cells, pericytes and adipose-derived stromal/stem cells (ASC) among others. Although possible clinical applications of autologous adipose tissue-derived cells are manifold, they are limited by insufficient uniformity in cell identity and regenerative potency.

METHODS

In our experimental set-up, low-energy extracorporeal shock wave therapy (ESWT) was performed on freshly obtained human adipose tissue and isolated adipose tissue SVF cells aiming to equalize and enhance stem cell properties and functionality.

RESULTS

After ESWT on adipose tissue we could achieve higher cellular adenosine triphosphate (ATP) levels compared with ESWT on the isolated SVF as well as the control. ESWT on adipose tissue resulted in a significantly higher expression of single mesenchymal and vascular marker compared with untreated control. Analysis of SVF protein secretome revealed a significant enhancement in insulin-like growth factor (IGF)-1 and placental growth factor (PLGF) after ESWT on adipose tissue.

DISCUSSION

Summarizing we could show that ESWT on adipose tissue enhanced the cellular ATP content and modified the expression of single mesenchymal and vascular marker, and thus potentially provides a more regenerative cell population. Because the effectiveness of autologous cell therapy is dependent on the therapeutic potency of the patient's cells, this technology might raise the number of patients eligible for autologous cell transplantation.

Extracorporeal Shockwave Therapy for Peripheral Arterial Disease: A Review of the Potential Mechanisms of Action

BACKGROUND

Lower limb peripheral arterial disease (PAD) affects 20% of population over 65 years. Extracorporeal shockwave therapy (ESWT) has recently emerged as a novel, safe, and effective treatment option. This review aims to assess the mechanism of action by which ESWT improves symptoms in patients with PAD.

METHODS

MEDLINE and EMBASE databases were searched in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Any article investigating the mechanism of action of ESWT in PAD was considered for inclusion.

RESULTS

The systematic review of the current literature yielded 8 relevant articles reporting studies on animal models of hind limb ischemia or on patients with PAD. These articles described the effects of ESWT on angiogenesis, arteriogenesis, vasculogenesis, endothelial nitric oxide synthase, lower limb micro/macrocirculation, and atherosclerosis.

CONCLUSION

ESWT increases the expression of angiogenic, arteriogenic, and vasculogenic factors, reduces vessel wall stenosis, and improves limb perfusion. However, most of the evidence is based on animal studies. Future research should focus on elucidating the mechanism of action of ESWT in PAD patients.

Radial extracorporeal shock wave therapy improves cerebral blood flow and neurological function in a rat model of cerebral ischemia

We performed middle cerebral artery occlusion (MCAO) in rats to investigate the effect and some of the underlying mechanisms of radial extracorporeal shock wave therapy (rESWT) in cerebral ischemia rats. We measured neurological function and cerebral blood flow (CBF) using a full-field laser perfusion imager and brain infarct volume on days 3, 12, and 30. Immunofluorescence, western blot, and real-time polymerase chain reaction (PCR) techniques were used to detect the expression of vascular endothelial growth factor (VEGF), neuron-specific enolase (NSE), nestin, Wnt3a, and β-catenin in the ischemic hemisphere. The dose of rESWT used on the head revealed remarkable advantages over sham rESWT, as demonstrated by improved neurological function scores, increased CBF, and reduced brain infarct volume. Furthermore, applying rESWT to the head and limbs enhanced short-term neurological function. Our results confirmed that rESWT can induce VEGF expression over an extended period with a profound effect, which may be the primary reason for CBF recovery. High NSE and nestin expression levels suggest that rESWT enhanced the number of neurons and neural stem cells (NSCs). Wnt3a and β-catenin expression were up-regulated in the ischemic hemisphere, indicating that rESWT promoted NSC proliferation and differentiation via the Wnt/β-catenin pathway. Overall, our findings suggest that an appropriate rESWT dose delivered to the head of rats helps restore neurological function and CBF, and additional application of rESWT to the limbs is more effective than treating the head alone.

Therapeutic ultrasound protects HUVECs from ischemia/hypoxia-induced apoptosis via the PI3K-Akt pathway

Background: Previous studies have demonstrated that therapeutic ultrasound (TUS) ameliorates angiogenesis on ischemic hind limb animals and also promotes human umbilical vein endothelial cells (HUVECs) tube formation. Apoptosis plays a key role in post-ischemic angiogenesis pathogenesis. However, the mechanisms underlying the anti-apoptotic effects of TUS are not clear. Therefore we put forward the hypothesis that TUS might promote angiogenesis during ischemia/hypoxia (I/H) by decreasing apoptosis. Methods: We investigated the cytoprotective role of TUS and the underlying mechanisms in I/H-induced HUVEC apoptosis. HUVECs were treated under hypoxic serum-starved conditions for 36 h and then treated with or without TUS (9 minutes, 1 MHz, 0.3 W/cm²). The cell viability was examined by the CCK-8 assay, apoptosis cell rate was determined by TUNEL staining and flow cytometry assay. In addition, the mitochondrial-dependent apoptosis pathway was evaluated by the protein activity of Bax, Bcl-2 and Caspase-3. Results: 1) apoptosis could be induced by I/H in HUVECs. 2) TUS attenuates HUVECs cell apoptosis induced by I/H. 3) TUS inhibits the protein expression of apoptosis modulators and effectors that regulate the mitochondrial pathway of apoptosis in HUVECs. 4) TUS increases the phosphorylation of Akt, which demonstrates the activation of the phosphoinositide 3-kinase (PI3K)- serine/threonine kinase (Akt) signal pathway. Conclusions: The present study indicates that exposure to TUS exerts a protective effect against I/H-induced apoptosis among HUVECs and that this process is mediated through the mitochondrial-dependent intrinsic apoptotic pathway. We also confirm that the PI3K-Akt signal cascade may be taken part in the TUS effects on apoptosis.

Shock wave treatment after hindlimb ischaemia results in increased perfusion and M2 macrophage presence

Shock wave therapy (SWT) has been shown to induce angiogenesis in ischaemic muscle. However, the mechanism of action remains unknown. Macrophages are crucial for angiogenic responses after ischaemic injury. The M2 macrophage subset enables tissue repair and induces angiogenesis. It was hypothesized that the angiogenic effects of SWT are at least partly caused by enhanced macrophage recruitment. C57BL/6 mice were subjected to hind limb ischaemia with subsequent SWT or sham treatment. Muscles were analysed via immunofluorescence staining, reverse-transcription polymerase chain reaction and western blot. Gene expression and proteins involved in macrophage recruitment were analysed and tissue sections were stained for macrophages, including subsets, capillaries and arterioles. Laser Doppler perfusion imaging was performed to assess functional outcome. Treated muscles showed increased expression of the pivotal macrophage recruiting factor monocyte chemotactic protein 1 (MCP-1). Higher levels of macrophage marker CD14 were found. Increased numbers of macrophages after SWT could be confirmed by immunofluorescence staining. The expression of the M2 polarization promoting chemokine interleukin 13 was significantly elevated in the treatment group. Elevated mRNA expression of the M2 scavenger receptor CD163 was found after SWT. Immunofluorescence staining confirmed increased numbers of M2 macrophages after treatment. It was found that SWT resulted in higher number of capillaries and arterioles. Assessment of functional outcome revealed significantly improved limb perfusion in treated animals. Shock wave therapy causes increased macrophage recruitment and enhanced polarization towards reparative M2 macrophages in ischaemic muscle resulting in angiogenesis and improved limb perfusion and therefore represents a promising new treatment option for the treatment of ischaemic heart disease. Copyright © 2016 John Wiley & Sons, Ltd.

Shockwaves prevent from heart failure after acute myocardial ischaemia via RNA/protein complexes

Shock wave treatment (SWT) was shown to induce regeneration of ischaemic myocardium via Toll‐like receptor 3 (TLR3). The antimicrobial peptide LL37 gets released by mechanical stress and is known to form complexes with nucleic acids thus activating Toll‐like receptors. We suggested that SWT in the acute setting prevents from the development of heart failure via RNA/protein release. Myocardial infarction in mice was induced followed by subsequent SWT. Heart function was assessed 4 weeks later via transthoracic echocardiography and pressure–volume measurements. Human umbilical vein endothelial cells (HUVECs) were treated with SWT in the presence of RNase and proteinase and analysed for proliferation, tube formation and LL37 expression. RNA release and uptake after SWT was evaluated. We found significantly improved cardiac function after SWT. SWT resulted in significantly higher numbers of capillaries and arterioles and less left ventricular fibrosis. Supernatants of treated cells activated TLR3 reporter cells. Analysis of the supernatant revealed increased RNA levels. The effect could not be abolished by pre‐treatment of the supernatant with RNase, but only by a sequential digestion with proteinase and RNase hinting strongly towards the involvement of RNA/protein complexes. Indeed, LL37 expression as well as cellular RNA uptake were significantly increased after SWT. We show for the first time that SWT prevents from left ventricular remodelling and cardiac dysfunction via RNA/protein complex release and subsequent induction of angiogenesis. It might therefore develop a potent regenerative treatment alternative for ischaemic heart disease.

Therapeutic potential of pro-angiogenic BPC157 is associated with VEGFR2 activation and up-regulation

BPC 157, a pentadecapeptide with extensive healing effects, has recently been suggested to contribute to angiogenesis. However, the underlying mechanism is not yet clear. The present study aimed to explore the potential therapeutic effect and pro-angiogenic mechanism of BPC 157. As demonstrated by the chick chorioallantoic membrane (CAM) assay and endothelial tube formation assay, BPC 157 could increase the vessel density both in vivo and in vitro, respectively. BPC 157 could also accelerate the recovery of blood flow in the ischemic muscle of the rat hind limb as detected by laser Doppler scanning, indicating the promotion of angiogenesis. Histological analysis of the hind limb muscle confirmed the increased number of vessels and the enhanced vascular expression of vascular endothelial growth factor receptor 2 (VEGFR2) in rat with BPC 157 treatment. In vitro study using human vascular endothelial cells further confirmed the increased mRNA and protein expressions of VEGFR2 but not VEGF-A by BPC 157. In addition, BPC 157 could promote VEGFR2 internalization in vascular endothelial cells which was blocked in the presence of dynasore, an inhibitor of endocytosis. BPC 157 time dependently activated the VEGFR2-Akt-eNOS signaling pathway which could also be suppressed by dynasore. The increase of endothelial tube formation induced by BPC 157 was also inhibited by dynasore. This study demonstrates the pro-angiogenic effects of BPC 157 that is associated with the increased expression, internalization of VEGFR2, and the activation of VEGFR2-Akt-eNOS signaling pathway. BPC 157 promotes angiogenesis in CAM assay and tube formation assay. BPC 157 accelerates the blood flow recovery and vessel number in rats with hind limb ischemia. BPC 157 up-regulates VEGFR2 expression in rats with hind limb ischemia and endothelial cell culture. BPC 157 promotes VEGFR2 internalization in association with VEGFR2-Akt-eNOS activation.

KEY MESSAGE

BPC 157 promotes angiogenesis in CAM assay and tube formation assay. BPC 157 accelerates the blood flow recovery and vessel number in rats with hind limb ischemia. BPC 157 up-regulates VEGFR2 expression in rats with hind limb ischemia and endothelial cell culture. BPC 157 promotes VEGFR2 internalization in association with VEGFR2-Akt-eNOS activation.

Extracorporeal shock wave therapy does not improve hypertensive nephropathy

Low-energy extracorporeal shock wave therapy (SWT) has been shown to improve myocardial dysfunction, hind limb ischemia, erectile function, and to facilitate cell therapy and healing process. These therapeutic effects were mainly due to promoting angiogenesis. Since chronic kidney diseases are characterized by renal fibrosis and capillaries rarefaction, they may benefit from a proangiogenic treatment. The objective of our study was to determine whether SWT could ameliorate renal repair and favor angiogenesis in L-NAME-induced hypertensive nephropathy in rats. SWT was started when proteinuria exceeded 1 g/mmol of creatinine and 1 week after L-NAME removal. SWT consisted of implying 0.09 mJ/mm(2) (400 shots), 3 times per week. After 4 weeks of SWT, blood pressure, renal function and urinary protein excretion did not differ between treated (LN + SWT) and untreated rats (LN). Histological lesions including glomerulosclerosis and arteriolosclerosis scores, tubular dilatation and interstitial fibrosis were similar in both groups. In addition, peritubular capillaries and eNOS, VEGF, VEGF-R, SDF-1 gene expressions did not increase in SWT-treated compared to untreated animals. No procedural complications or adverse effects were observed in control (C + SWT) and hypertensive rats (LN + SWT). These results suggest that extracorporeal kidney shock wave therapy does not induce angiogenesis and does not improve renal function and structure, at least in the model of hypertensive nephropathy although the treatment is well tolerated.

Shock wave as biological therapeutic tool: From mechanical stimulation to recovery and healing, through mechanotransduction

Extracorporeal Shock Wave Therapy (ESWT) is a form of "mechanotherapy", that, from its original applications as urological lithotripsy, gained the field of musculo-skeletal diseases as Orthotripsy (mainly tendinopaties and bone regenerative disorders) and Regenerative Medicine as well. The mechanisms of action of Shock Waves (SW), when applied in non-urological indications, are not related to the direct mechanical effect, but to the different pathways of biological reactions, that derive from that acoustic stimulations, through "mechano-transduction". So, the "mechanical model" of urological lithotripsy has been substituted by a "biological model", also supported by current knowledge in "mechanobiology", the emerging multidisciplinary field of science that investigates how physical forces and changes in cell/tissue mechanics can influence the tissue development, physiology and diseases. Although some details are still under study, it is known that SW are able to relief pain, as well to positively regulate inflammation (probably as immunomodulator), to induce neoangiogenesis and stem cells activities, thus improving tissue regeneration and healing. ESWT can be nowadays considered an effective, safe, versatile, repeatable, noninvasive therapy for the treatment of many musculo-skeletal diseases, and for some pathological conditions where regenerative effects are desirable, especially when some other noninvasive/conservative therapies have failed. Moreover, based on the current knowledge in SW mechanobiology, it seems possible to foresee new interesting and promising applications in the fields of Regenerative Medicine, tissue engineering and cell therapies.

Effect of shock waves on macrophages: A possible role in tissue regeneration and remodeling

INTRODUCTION

Extracorporeal Shock Wave Therapy (ESWT) is broadly used as a non-surgical therapy in various diseases for its pro-angiogenic and anti-inflammatory effects. However, the molecular mechanisms translating tissue exposure to shock waves (SW) in a biological response with potential therapeutic activity are largely unknown. As macrophages take part in both the onset and amplification of the inflammatory response, and well in its resolution, we investigated the effect of SW on their biology.

METHODS

Human monocyte-derived macrophages were polarized to classic (M1) pro-inflammatory macrophages or alternative (M2) anti-inflammatory macrophages and exposed to SW ad different intensities. Expression levels of marker genes of macrophage activation were measured by qPCR at different time points.

RESULTS

SW did not induce activation of resting macrophages at any energy level used. Conversely, when used at low energy SW caused a significant inhibition of some M1 marker genes (CD80, COX2, CCL5) in M1 macrophages and a significant synergistic effect for some M2 marker genes (ALOX15, MRC1, CCL18) in M2 macrophages. SW also affected cytokine and chemokine production, inducing in particular a significant increase in IL-10 and reduction in IL-1β production.

CONCLUSIONS

Macrophage exposure to low energy SW dampens the induction of the pro-inflammatory profile characterizing M1 macrophages and promotes the acquisition of an anti-inflammatory profile synergizing with macrophage alternative activation.

Angiogenesis effect of therapeutic ultrasound on HUVECs through activation of the PI3K-Akt-eNOS signal pathway

Therapeutic angiogenic effects of low-intensity ultrasound have been reported in endothelial cells and animal models of hind limb ischemia. It has been shown that the proliferation, migration, and tube formation of endothelial cells play critical roles in angiogenesis. The purpose of this study was to determine the underlying mechanism of low-intensity continuous therapeutic ultrasound on angiogenesis in endothelial cells. In the present study, human umbilical vein endothelial cells (HUVECs) were simulated of low-intensity therapeutic ultrasound (TUS, 1 MHz, 0.3 W/cm(2), 9 minute per day) for 3 days, and we observed migration, tube formation, and expression of endothelial nitric oxide synthase (eNOS) and serine/threonine kinase (Akt) in HUVECs. Specific inhibitors of eNOS and phosphoinositide 3-kinase (PI3K) were added to the culture medium and TUS-induced changes in the pathways that mediate angiogenesis were investigated. After exposure to TUS, HUVECs tube formation and migration were significantly promoted, which was blocked by the eNOS inhibitor Immunofluorescence assay and Western blotting analysis demonstrated that eNOS expression in the HUVECs was significantly increased after TUS exhibition. Proteins of phosphorylated eNOS and Akt were both up-regulated after TUS stimulation. However, the specific inhibitor of PI3K not only significantly decreased the expression of p-Akt, but also down-regulated the p-eNOS. This suggested that the PI3K/Akt signal pathway might participate in modulating the activity of eNOS. In short, TUS therapy promotes angiogenesis through activation of the PI3K-Akt-eNOS signal cascade in HUVECs.

Beetroot juice reduces infarct size and improves cardiac function following ischemia-reperfusion injury: Possible involvement of endogenous H2S

Ingestion of high dietary nitrate in the form of beetroot juice (BRJ) has been shown to exert antihypertensive effects in humans through increasing cyclic guanosine monophosphate (cGMP) levels. Since enhanced cGMP protects against myocardial ischemia-reperfusion (I/R) injury through upregulation of hydrogen sulfide (H2S), we tested the hypothesis that BRJ protects against I/R injury via H2S. Adult male CD-1 mice received either regular drinking water or those dissolved with BRJ powder (10 g/L, containing ∼ 0.7 mM nitrate). Seven days later, the hearts were explanted for molecular analyses. Subsets of mice were subjected to I/R injury by occlusion of the left coronary artery for 30 min and reperfusion for 24 h. A specific inhibitor of H2S producing enzyme--cystathionine-γ-lyase (CSE), DL-propargylglycine (PAG, 50 mg/kg) was given i.p. 30 min before ischemia. Myocardial infarct size was significantly reduced in BRJ-fed mice (15.8 ± 3.2%) versus controls (46.5 ± 3.5%, mean ± standard error [SE], n = 6/group, P < .05). PAG completely blocked the infarct-limiting effect of BRJ. Moreover, BRJ significantly preserved ventricular function following I/R. Myocardial levels of H2S and its putative protein target--vascular endothelial growth factor receptor 2 (VEGFR2) were significantly increased by BRJ intake, whereas CSE mRNA and protein content did not change. Interestingly, the BRJ-induced cardioprotection was not associated with elevated blood nitrate-nitrite levels following I/R nor induction of cardiac peroxiredoxin 5, a mitochondrial antioxidant enzyme previously linked to nitrate-induced cardioprotection. We conclude that BRJ ingestion protects against post-I/R myocardial infarction and ventricular dysfunction possibly through CSE-mediated endogenous H2S generation. BRJ could be a promising natural and inexpensive nutraceutical supplement to reduce cardiac I/R injury in patients.