Propranolol-mediated attenuation of MMP-9 excretion in infants with hemangiomas

Recent progress in mass spectrometry-based urinary proteomics

Serum or plasma is frequently utilized in biomedical research; however, its application is impeded by the requirement for invasive sample collection. The non-invasive nature of urine collection makes it an attractive alternative for disease characterization and biomarker discovery. Mass spectrometry-based protein profiling of urine has led to the discovery of several disease-associated biomarkers. Proteomic analysis of urine has not only been applied to disorders of the kidney and urinary bladder but also to conditions affecting distant organs because proteins excreted in the urine originate from multiple organs. This review provides a progress update on urinary proteomics carried out over the past decade. Studies summarized in this review have expanded the catalog of proteins detected in the urine in a variety of clinical conditions. The wide range of applications of urine analysis-from characterizing diseases to discovering predictive, diagnostic and prognostic markers-continues to drive investigations of the urinary proteome.

The Use of β-Blockers and the Risk of Undergoing a Knee Arthroplasty: A Nested Case-Control Study

BACKGROUND

Research has indicated that β-blockers may downregulate various inflammatory mediators that are involved in osteoarthritis (OA). The objective of this study was to analyze the likelihood of total knee arthroplasty (TKA) among patients with OA who were being treated with β-blockers.

METHODS

A nested case-control study was conducted with use of clinical records from our institutional database. We included patients who attended our outpatient clinic with a history of new-onset knee pain between 2010 and 2019. The case group included individuals who had undergone primary TKA between 2018 and 2019, whereas the control group included subjects who had not undergone TKA. Controls were matched by date of birth ±2 years, sex, calendar time (first outpatient visit ±1 year), and the grade of arthritis; the control-to-case ratio was 1:1. Adherence to β-blocker use was measured with use of the proportion of days covered (PDC) (i.e.,<0.25, ≥0.25 to <0.75, ≥0.75), and the cumulative effect was measured on the basis of the total number of years of treatment with β-blockers. A binary logistic regression analysis adjusted to potential confounders was carried out to assess the risk of TKA associated with the intake of β-blockers.

RESULTS

A total of 600 patients were included (300 in the case group and 300 in the control group). Compared with non-users, any use of β-blockers during the follow-up period was associated with a reduction in the likelihood of undergoing TKA (adjusted odds ratio [OR], 0.51; 95% confidence interval [CI], 0.34-0.77). The adjusted ORs for the use of selective β1-blockers and nonselective β1-blockers were 0.69 (95% CI, 0.36 to 1.31) and 0.42 (95% CI, 0.24 to 0.70), respectively. The adjusted ORs for any recent use, PDC of <0.25, PDC of ≥0.25 to <0.75, and PDC of ≥0.75 were 0.65 (95% CI, 0.51 to 0.99), 0.62 (95% CI, 0.21 to 1.85), 0.32 (95% CI, 0.09 to 1.22), and 0.55 (95% CI, 0.34 to 0.88), respectively. Regarding the cumulative effect of β-blockers, the adjusted ORs for the use for <1 year, ≥1 to <5 years, and ≥5 years were 0.41 (95% CI, 0.20 to 0.85), 0.52 (95% CI, 0.21 to 1.33), and 0.36 (95% CI, 0.22 to 0.60), respectively.

CONCLUSIONS

The use of nonselective β-blockers was associated with a lower likelihood of undergoing TKA. Patients treated for prolonged periods were at a lower likelihood for undergoing TKA.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Research advances in drug therapy for abdominal aortic aneurysms over the past five years: An updated narrative review

BACKGROUND

Abdominal aortic aneurysms (AAA) rupture can lead to patient death. Surgical treatment is currently the optimal treatment for AAA with large diameter (≥50 mm). For AAA with small diameter (30-50 mm), how to administer effective pharmacological treatment to reduce aneurysm expansion rate and rupture risk is the current focus in the field of vascular surgery. There is still no effective drug for the treatment of asymptomatic AAA.

METHODS

This article searches the PubMed, Web of Science, Embase, and Cochrane databases for clinical studies on the drug treatment of abdominal aortic aneurysms in the past 5 years. The latest progress in the drug treatment of AAA was reviewed, including antibiotics, antihypertensive drugs, antiplatelet drugs, hypoglycemic drugs, hypolipidemic drugs, mast cell inhibitors and corticosteroids.

RESULTS

25 studies were included in this narrative review. Among them, metformin revealed therapeutic effect in 2 prospective cohort study and 3 retrospective cohort study. The therapeutic effect of statins was controversial in 3 retrospective cohort study. However, the definite therapeutic effects of antihypertensive agents, antibiotics, mast cell inhibitors, antiplatelet agents and corticosteroids on abdominal aortic aneurysms have not been verified in prospective studies.

CONCLUSION

Metformin provided a positive effect in reducing expansion rate, rupture risk, and perioperative mortality. The therapeutic effect of statins was controversial, which warrant further validation in prospective cohorts. However, there is still a lack of effective agents for the treatment of AAA based on recent studies.

Overexpression of Annexin A1 is associated with the formation of capillaries in infantile hemangioma

Infantile hemangioma is a common benign tumor in infants. However, the molecular mechanism that controls the proliferation and differentiation of hemangioma is not well understood. Annexin A1 (ANX A1) is a phospholipid-binding protein involved in a variety of biological processes, including inflammation, cell proliferation and apoptosis. To explore the significance of ANX A1 in the process of proliferation or differentiation of hemangioma, proliferating and involuting hemangioma tissues were collected to detect the expression of ANX A1 using immunohistochemistry and western blotting. Normal skin tissues were used as the negative control. The results revealed that ANX A1 was upregulated in the proliferative phase of hemangioma, and its expression was decreased when the hemangioma entered the involuting phase. Additionally, in the proliferative phase, the strongest staining of ANX A1 was observed in newly born capillaries, and the staining of ANX A1 became weaker in enlarged vessels, indicating that ANX A1 plays an important role in promoting the formation of capillaries. The expression of hypoxia-inducible factor (HIF)-1α was positively associated with the expression trend of ANX A1, suggesting that the overexpression of ANX A1 may be associated with the increase of HIF-1α. In summary, the results of the present study revealed that the expression of ANX A1 was increased in proliferating hemangioma tissue, and that high expression of ANX A1 may be closely associated with the formation of capillaries in infantile hemangioma.

The effectiveness and safety of topical β-receptor blocker in treating superficial infantile haemangiomas: A meta-analysis including 20 studies

AIMS

To evaluate the effectiveness and safety of topical β-receptor blocker in treating superficial infantile haemangiomas (SIH) and compare the effectiveness and safety of topical β-receptor blocker against other therapies.

METHODS

A search of the literature using PubMed, Embase, Cochrane Review database, China National Knowledge Infrastructure and Wanfang were performed to identify the studies that estimated the effectiveness and safety of topical β-receptor blocker in treating SIH, the fixed-effect or random-effects meta-analytical techniques were applied to assess the outcomes.

RESULTS

Twenty studies, involving 2098 patients, were included to conduct this analysis. Topical propranolol and topical timolol were discovered to be as effective as oral propranolol in treating SIH (propranolol, odds ratio [OR] = 0.486, 95% confidence interval [CI] 0.165, 1.426, P = .189; timolol, OR = 0.955; 95%CI 0.700, 1.302; P = .769), and topical timolol was more effective than topical imiquimod (OR = 2.561; 95%CI 1.182, 5.550; P = .017), observation (OR = 18.458; 95%CI 5.660, 60.191; P < .001) and topical saline solutions (OR = 19.193; 95%CI 8.837, 41.683; P < .001) in treating SIH. The comparison between topical propranolol and oral propranolol led to no discovery of significant difference in the incidence of adverse effects (OR = 1.258; 95%CI 0.471, 3.358; P = .647). Compared with oral propranolol, topical timolol was associated with fewer incidences of adverse effects (OR = 0.191; 95%CI 0.043, 0.858; P = .031). No significant difference in the incidence of adverse effects was found when topical timolol and topical imiquimod were compared (OR = 0.077; 95%CI 0.005, 1.206; P = .068).

CONCLUSION

This meta-analysis provided evidence that topical β-receptor blockers (propranolol and timolol), especially timolol, may replace oral propranolol as a first-line treatment for SIH.

Oral propranolol in the treatment of proliferating infantile haemangiomas: British Society for Paediatric Dermatology consensus guidelines

BACKGROUND

Infantile haemangiomas (IH) are the most common vascular tumours of infancy. Despite their frequency and potential complications, there are currently no unified U.K. guidelines for the treatment of IH with propranolol. There are still uncertainties and diverse opinions regarding indications, pretreatment investigations, its use in PHACES (posterior fossa malformations-haemangiomas-arterial anomalies-cardiac defects-eye abnormalities-sternal cleft and supraumbilical raphe) syndrome and cessation of treatment.

OBJECTIVES

To provide unified guidelines for the treatment of IH with propranolol.

METHODS

This study used a modified Delphi technique, which involved an international treatment survey, a systematic evidence review of the literature, a face-to-face multidisciplinary panel meeting and anonymous voting.

RESULTS

The expert panel achieved consensus on 47 statements in eight categories, including indications and contraindications for starting propranolol, pretreatment investigations, starting and target dose, monitoring of adverse effects, the use of propranolol in PHACES syndrome and how to stop treatment.

CONCLUSIONS

These consensus guidelines will help to standardize and simplify the treatment of IH with oral propranolol across the U.K. and assist in clinical decision-making.

Interleukin-6, tumor necrosis factor-α, C-reactive protein, and hematological parameters in experimental periodontal disease after β-adrenergic blockade

Background:

Changes in the levels of C-reactive protein (CRP), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) observed during periodontal disease were linked with vascular manifestations. Recent studies showed that the beta-blocker propranolol reduces the pathological parameters associated with certain molecules at sites of bone injury. Hence, in this study, we evaluated the activity of propranolol on hematological parameters and systemic concentrations of inflammatory proteins in a model of experimental periodontitis.

Materials and Methods:

Periodontal disease was induced in rats. After euthanasia, the number of inflammatory cells in each rat was quantified using histopathological assays. In addition, hematological parameters were quantitated using automated analysers, cytokine levels were determined using an enzyme-linked immunosorbent assay, and CRP levels were determined using a high-sensitivity immunoturbidimetric assay.

Results:

Low doses of propranolol suppressed the systemic production of CRP, TNF-α, and IL-6; however, the hematological parameters were not affected.

Conclusions:

β-adrenergic activation indirectly contributes to the pattern of systemic inflammatory molecules observed in periodontal disease. These molecules may initiate cardiovascular diseases as a consequence of periodontitis.

Interventions for infantile haemangiomas of the skin: abridged Cochrane systematic review and GRADE assessments

BACKGROUND

Infantile haemangiomas (IH) are soft swellings of the skin that occur in 3-10% of infants. When haemangiomas occur in high-risk areas or when complications develop, active intervention is necessary.

OBJECTIVE

To update a Cochrane Review assessing the interventions for the management of IH in children.

METHODS

We searched for randomized controlled trials in CENTRAL, MEDLINE, Embase, LILACS, AMED, PsycINFO, CINAHL and six trials registers up to February 2017. We included 28 trials (1728 participants) assessing 12 interventions.

RESULTS

We downgraded evidence from high to moderate/low for issues related to risk of bias and imprecision. Oral propranolol (3 mg kg^-1 daily) probably improves clinician-assessed clearance vs placebo [risk ratio (RR) 16·61, 95% confidence interval (CI) 4·22-65·34; moderate quality of evidence (QoE)]; we found no evidence of a difference in terms of serious adverse events (RR 1·05, 95% CI 0·33-3·39; low QoE). We found the chance of reduction of redness may be improved with topical timolol maleate (0·5% gel applied twice daily) when compared with placebo (RR 8·11, 95% CI 1·09-60·09; low QoE). We found no instances of bradycardia or hypotension for this comparison.

CONCLUSIONS

Our key results indicate that oral propranolol and topical timolol maleate are more beneficial than placebo in terms of clearance or other measures of resolution, or both, without an increase in harm.

Interventions for infantile haemangiomas of the skin

BACKGROUND

Infantile haemangiomas (previously known as strawberry birthmarks) are soft, raised swellings of the skin that occur in 3% to 10% of infants. These benign vascular tumours are usually uncomplicated and tend to regress spontaneously. However, when haemangiomas occur in high-risk areas, such as near the eyes, throat, or nose, impairing their function, or when complications develop, intervention may be necessary. This is an update of a Cochrane Review first published in 2011.

OBJECTIVES

To assess the effects of interventions for the management of infantile haemangiomas in children.

SEARCH METHODS

We updated our searches of the following databases to February 2017: the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, AMED, LILACS, and CINAHL. We also searched five trials registries and checked the reference lists of included studies for further references to relevant trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of all types of interventions, versus placebo, active monitoring, or other interventions, in any child with single or multiple infantile haemangiomas (IHs) located on the skin.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. The primary outcome measures were clearance, a subjective measure of improvement, and adverse events. Secondary outcomes were other measures of resolution; proportion of parents or children who consider there is still a problem; aesthetic appearance; and requirement for surgical correction. We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics.

MAIN RESULTS

We included 28 RCTs, with a total of 1728 participants, assessing 12 different interventions, including lasers, beta blockers (e.g. propranolol, timolol maleate), radiation therapy, and steroids. Comparators included placebo, an active monitoring approach, sham radiation, and interventions given alone or in combination.Studies were conducted in a number of countries, including China, Egypt, France, and Australia. Participant age ranged from 12 weeks to 13.4 years. Most studies (23/28) included a majority of females and different types of IHs. Duration of follow-up ranged from 7 days to 72 months.We considered most of the trials as at low risk of random sequence generation, attrition bias, and selective reporting bias. Domains such as allocation concealment and blinding were not clearly reported in general. We downgraded evidence for issues related to risk of bias and imprecision.We report results for the three most important comparisons, which we chose on the basis of current use. Outcome measurement of these comparisons was at 24 weeks' follow-up.Oral propranolol versus placeboCompared with placebo, oral propranolol 3 mg/kg/day probably improves clinician-assessed clearance (risk ratio (RR) 16.61, 95% confidence interval (CI) 4.22 to 65.34; 1 study; 156 children; moderate-quality evidence) and probably leads to a clinician-assessed reduction in mean haemangioma volume of 45.9% (95% CI 11.60 to 80.20; 1 study; 40 children; moderate-quality evidence). We found no evidence of a difference in terms of short- or long-term serious adverse events (RR 1.05, 95% CI 0.33 to 3.39; 3 studies; 509 children; low-quality evidence), nor in terms of bronchospasm, hypoglycaemia, or serious cardiovascular adverse events. The results relating to clearance and resolution for this comparison were based on one industry-sponsored study.Topical timolol maleate versus placeboThe chance of reduction of redness, as a measure of clinician-assessed resolution, may be improved with topical timolol maleate 0.5% gel applied twice daily when compared with placebo (RR 8.11, 95% CI 1.09 to 60.09; 1 study; 41 children;low-quality evidence). Regarding short- or long-term serious cardiovascular events, we found no instances of bradycardia (slower than normal heart rate) or hypotension in either group (1 study; 41 children; low-quality evidence). No other safety data were assessed, and clearance was not measured.Oral propranolol versus topical timolol maleateWhen topical timolol maleate (0.5% eye drops applied twice daily) was compared with oral propranolol (via a tablet taken once per day, at a 1.0 mg/kg dose), there was no evidence of a difference in haemangioma size (as a measure of resolution) when measured by the proportion of patients with a clinician-assessed reduction of 50% or greater (RR 1.13, 95% CI 0.64 to 1.97; 1 study; 26 participants; low-quality evidence). Although there were more short- or long-term general adverse effects (such as severe diarrhoea, lethargy, and loss of appetite) in the oral propranolol group, there was no evidence of a difference between groups (RR 7.00, 95% CI 0.40 to 123.35; 1 study; 26 participants; very low-quality evidence). This comparison did not measure clearance.None of our key comparisons evaluated, at any follow-up, a subjective measure of improvement assessed by the parent or child; proportion of parents or children who consider there is still a problem; or physician-, child-, or parent-assessed aesthetic appearance.

AUTHORS' CONCLUSIONS

We found there to be a limited evidence base for the treatment of infantile haemangiomas: a large number of interventions and outcomes have not been assessed in RCTs.Our key results indicate that in the management of IH in children, oral propranolol and topical timolol maleate are more beneficial than placebo in terms of clearance or other measures of resolution, or both, without an increase in harms. We found no evidence of a difference between oral propranolol and topical timolol maleate with regard to reducing haemangioma size, but we are uncertain if there is a difference in safety. Oral propranolol is currently the standard treatment for this condition, and our review has not found evidence to challenge this. However, these results are based on moderate- to very low-quality evidence.The included studies were limited by small sample sizes and risk of bias in some domains. Future trials should blind personnel and participants; describe trials thoroughly in publications; and recruit a sufficient number of children to deduce meaningful results. Future trials should assess patient-reported outcomes, as well as objective outcomes of benefit, and should report adverse events comprehensively. Propranolol and timolol maleate require further assessment in RCTs of all types of IH, including those considered problematic, as do other lesser-used interventions and new interventions. All treatments should be compared against propranolol and timolol maleate, as beta blockers are approved as standard care.

Epigenetic silencing of miR-130a ameliorates hemangioma by targeting tissue factor pathway inhibitor 2 through FAK/PI3K/Rac1/mdm2 signaling

Hemangiomas are the most common vascular tumors that occur frequently in prematures and females. microRNA (miR)-130a is associated with the growth and invasion in many tumors, and its role in hemangiomas has not been addressed so far. The present study revealed that miR‑130a was overexpressed in infantile hemangioma tissues compared with matched tumor-adjacent tissues. The inhibitor of miR-130a restrained cell growth and induced cell apoptosis in vitro. miR‑130a inhibitor also induced a cell cycle arrest at G2/M phase. Further studies revealed that tissue factor pathway inhibitor 2 (TFPI2) was a novel miR-130a target, due to miR-130a bound directly to its 3'-untranslated region and miR-130a inhibitor enhanced the expression of TFPI2. Contrary to the effects of miR-130a inhibitor, TFPI2 siRNA strongly promoted cell growth and colony formation, whereas TFPI2 overexpression contributed to the suppressing effect of miR-130a inhibitor in cell viability. Furthermore, miR-130a inhibitor reduced the activation of focal adhesion kinase (FAK)/phosphoinositide 3-kinase (PI3K)/Rac1/anti-mouse double minute (mdm2) pathway proteins, inhibited the expression and nuclear translocation of mdm2. Moreover, FAK overexpression prevented miR-130a inhibitor-induced cell cycle arrest and decrease of cell viability. In vivo experiments, miR-130a inhibition effectively suppressed the tumor growth, restrained angiogenesis by decreasing the expression of angiogenesis markers and the percentage of CD31+ and CD34+. Taken together, our research indicated that miR-130a functions as an oncogene by targeting TFPI2, miR-130a inhibition reduced the growth and angiogenesis of hemangioma by inactivating the FAK/PI3K/Rac1/mdm2 pathway. Thus, miR-130a may serve as a potential therapeutic strategy for the treatment of hemangioma.

Temperature Instability in an Infant Treated with Propranolol for Infantile Hemangioma

Infantile hemangiomas are prevalent in the first few months of life and can be associated with risks of scarring, blindness, ulcerations, and airway obstruction depending on the location of lesions. Options for therapy include surgery, laser therapy, or medications. Propranolol is the only US Food and Drug Administration-approved medication option. Propranolol is a nonselective beta-blocker that crosses the blood-brain barrier because of its high lipophilicity, which increases the likelihood of central nervous system effects. In this case, a preterm infant developed infantile hemangiomas on the left forearm, left trunk, left buttock, and nasal tip. The patient was treated with propranolol and concurrently required placement into a heated incubator and was subsequently unable to wean from the incubator. Upon discontinuation of propranolol, temperature instability resolved. Atenolol, a cardioselective beta-blocker that does not cross the blood-brain barrier, was then initiated for the infantile hemangiomas and displayed no adverse effect on the thermoregulation of the infant.

Effect of β-blocker on aneurysm sac behavior after endovascular abdominal aortic repair

OBJECTIVE

This study was conducted to determine whether β-blocker (BB) therapy is associated with abdominal aortic aneurysm (AAA) sac regression after endovascular abdominal aortic repair (EVAR).

METHODS

A total of 198 patients (mean age, 76 years) who underwent EVAR were analyzed (104 in the BB group and 94 in the non-BB group). The primary end point was the incidence of AAA sac regression at 1 and 2 years.

RESULTS

Hypertension, coronary artery disease, and hyperlipidemia were more common in the BB group. The BB group was also more likely to have been prescribed an aspirin and a statin than the non-BB group. The length of proximal neck was significantly longer in the non-BB group than in the BB group. All study patients were monitored for at least 1 year after EVAR, and 2-year follow-up was available in 104 patients (52.5%). There was no statistically significant difference in the incidence of aneurysm sac regression in either group at 1 year (52.1% in the non-BB group vs 45.2% in the BB group; P = .330) and 2 years (58.5% in the non-BB group vs 64.7% in the BB group; P = .515). The difference of the change of AAA maximum diameter between two groups did not reach statistical significance at 1 year (-6.0 ± 7.0 mm in the non-BB group vs -5.5 ± 8.1 mm in the BB group; P = .644) and 2 years (-9.0 ± 10.5 mm in the non-BB group vs -9.0 ± 10.0 mm in the BB group; P = .977). BB therapy was not associated with increased odds of AAA sac regression. The effect of third-generation BBs on AAA sac regression was not significant.

CONCLUSIONS

BB therapy had no effect on AAA sac regression. At the present time, there is insufficient evidence to recommend BB therapy for the purpose of AAA sac regression.

Repurposing Drugs in Oncology (ReDO)-Propranolol as an anti-cancer agent

Propranolol (PRO) is a well-known and widely used non-selective beta-adrenergic receptor antagonist (beta-blocker), with a range of actions which are of interest in an oncological context. PRO displays effects on cellular proliferation and invasion, on the immune system, on the angiogenic cascade, and on tumour cell sensitivity to existing treatments. Both pre-clinical and clinical evidence of these effects, in multiple cancer types, is assessed and summarised and relevant mechanisms of action outlined. In particular there is evidence that PRO is effective at multiple points in the metastatic cascade, particularly in the context of the post-surgical wound response. Based on this evidence the case is made for further clinical investigation of the anticancer effects of PRO, particularly in combination with other agents. A number of trials are on-going, in different treatment settings for various cancers.

A case of giant fetal intracranial capillary hemangioma cured with propranolol

Fetal brain tumors are rare. This report describes a giant posterior fossa capillary hemangioma treated with 3 mg/kg/day of propranolol for 6 months. Total regression was confirmed at 1 year, and no additional tumors were observed during the subsequent 2 years. No side effects relating to the use of this drug were detected; thus, the authors believe that propranolol may be useful for treating all intracranial capillary hemangiomas.

Propranolol induces regression of hemangioma cells via the down-regulation of the PI3K/Akt/eNOS/VEGF pathway

BACKGROUND

Infantile hemangioma (IH) is a benign vascular neoplasm resulting from the abnormal proliferation of endothelial cells and pericytes in infants. Propranolol, a non-selective β-adrenergic blocker, has recently emerged as an effective therapy for IH, causing regression. However, its potential therapeutic mechanism remains largely unknown.

PROCEDURE

An XPTS-1 cell line was established by isolating hemangioma-derived endothelial cells (HemECs) from a specimen of human proliferating IH. Flow cytometer assay was performed to assess the effect of propranolol on cell cycle distribution. Western blot was employed to determine changes of protein expression. Matrigel invasion and tube formation assays were used to measure invasion ability and tube formation ability, respectively. Commercial kits were employed to quantify NO and VEGF levels.

RESULTS

Propranolol blocked norepinephrine-induced HemECs cell cycle progression as well as the expression of cyclin A2 and cyclin D2; whereas p21 and p27 proteins were altered conversely. Propranolol inhibited norepinephrine-induced cell invasion by reducing the expression of MMP-9, VEGF, and p-cofilin. NO and VEGF release induced by norepinephrine was decreased by propranolol pretreatment, coincident with alterations in the phosphorylation of Akt, eNOS, and VEGFR-2. Tube formation ability and subsequent levels of NO and VEGF elevated by norepinephrine were distinctively counteracted in HemECs.

CONCLUSIONS

The current study demonstrated the antiangiogenic properties of propranolol in vitro and that the drug was able to induce the regression of hemangioma cells via the inhibition of cell cycle progression, invasion, and tube formation, concomitantly with decreased NO and VEGF levels through the down-regulation of the PI3K/Akt/eNOS/VEGF pathway.

Infantile hemangiomas, retinopathy of prematurity and cancer: a common pathogenetic role of the β-adrenergic system

The serendipitous demonstration that the nonselective β-adrenergic receptor (β-AR) antagonist propranolol promotes the regression of infantile hemangiomas (IHs) aroused interest around the involvement of the β-adrenergic system in angiogenic processes. The efficacy of propranolol was related to the β2-AR blockade and the consequent inhibition of the production of vascular endothelial growth factor (VEGF), suggesting the hypothesis that propranolol could also be effective in treating retinopathy of prematurity (ROP), a retinal pathology characterized by VEGF-induced neoangiogenesis. Consequent to the encouraging animal studies, a pilot clinical trial showed that oral propranolol protects newborns from ROP progression, even though this treatment is not sufficiently safe. Further, animal studies clarified the role of β3-ARs in the development of ROP and, together with several preclinical studies demonstrating the key role of the β-adrenergic system in tumor progression, vascularization, and metastasis, prompted us to also investigate the participation of β3-ARs in tumor growth. The aim of this review is to gather the recent findings on the role of the β-adrenergic system in IHs, ROP, and cancer, highlighting the fact that these different pathologies, triggered by different pathogenic noxae, share common pathogenic mechanisms characterized by the presence of hypoxia-induced angiogenesis, which may be contrasted by targeting the β-adrenergic system. The mechanisms characterizing the pathogenesis of IHs, ROP, and cancer may also be active during the fetal-neonatal development, and a great contribution to the knowledge on the role of β-ARs in diseases characterized by chronic hypoxia may come from research focusing on the fetal and neonatal period.

The use of propranolol in the treatment of infantile haemangiomas: an update on potential mechanisms of action

Currently, propranolol is the preferred treatment for problematic proliferating infantile haemangiomas (IHs). The rapid action of propranolol has been shown to be especially dramatic in IHs involving dyspnoea, haemodynamic compromise, palpebral occlusion or ulceration. Another remarkable aspect of propranolol treatment revealed that the growth of the IHs was not only stabilized, but also that the improvement continued until complete involution was achieved, leading to a considerable shortening of the natural course of IH. However, the mechanisms underlying the effects of propranolol have not been fully elucidated. Recent studies have offered evidence of a variety of mechanisms. These include the promotion of pericyte-mediated vasoconstriction, the inhibition of vasculogenesis and catecholamine-induced angiogenesis, the disruption of haemodynamic force-induced cell survival, and the inactivation of the renin-angiotensin system. This review summarizes these mechanisms and the new concepts that are emerging in this area of research. Moreover, several molecular mechanisms by which propranolol may modify neovascularization in IH have also been proposed. The antihaemangioma effect of propranolol may not be attributable to a single mechanism, but rather to a combination of events that have not yet been elucidated or understood. Further studies are needed to evaluate and verify these mechanisms to gain a greater understanding of the effects of the intake of propranolol on haemangioma involution.