Relation of nocturnal melatonin levels to serum matrix metalloproteinase-9 concentrations in patients with myocardial infarction

Clinical Radiological and Molecular Profile of a Patient Affected With Multicentric Osteolysis Nodulosis and Arthropathy

Multicentric Osteolysis Nodulosis and Arthropathy (MONA) is an ultra-rare multisystem autosomal recessive disorder characterized by progressive osteolysis, subcutaneous nodules and developing arthropathy. The characteristic radiological signs combined with symptoms resembling juvenile idiopathic arthritis (JIA) set the diagnosis, which is established either by measuring matrix metalloproteinase-2 (MMP-2) enzyme activity through electrophoresis (zymography) or genomic testing. We report the clinical and radiographic findings of a 14-year-old girl with molecularly proven MONA, who presented with painless osteolytic changes of the feet and upper extremities and developed hip arthritis. To this day, no specific therapy has been identified with proven long term relief and control of the disease progression.

Cardioprotective Role of Melatonin in Acute Myocardial Infarction

Melatonin is a pleiotropic, indole secreted, and synthesized by the human pineal gland. Melatonin has biological effects including anti-apoptosis, protecting mitochondria, anti-oxidation, anti-inflammation, and stimulating target cells to secrete cytokines. Its protective effect on cardiomyocytes in acute myocardial infarction (AMI) has caused widespread interest in the actions of this molecule. The effects of melatonin against oxidative stress, promoting autophagic repair of cells, regulating immune and inflammatory responses, enhancing mitochondrial function, and relieving endoplasmic reticulum stress, play crucial roles in protecting cardiomyocytes from infarction. Mitochondrial apoptosis and dysfunction are common occurrence in cardiomyocyte injury after myocardial infarction. This review focuses on the targets of melatonin in protecting cardiomyocytes in AMI, the main molecular signaling pathways that melatonin influences in its endogenous protective role in myocardial infarction, and the developmental prospect of melatonin in myocardial infarction treatment.

Clock-Bmal1 mediates MMP9 induction in acrolein-promoted atherosclerosis associated with gut microbiota regulation

Circadian rhythm is believed to play important roles in atherosclerosis. The gut microbiota is found to be closely related to atherogenesis, and shows compositional and functional circadian oscillation. However, it's still unclarified whether circadian clock and intestinal microbiota are involved in the progression of atherosclerosis induced by environmental pollutant acrolein. Herein, patients with atherosclerosis showed higher MMP9, a promising biomarker for atherosclerosis, and lower Bmal1 and Clock expression in the plasma. Interestingly, acrolein exposure contributed to the increased MMP9, decreased Clock and Bmal1, and activated MAPK pathways in human umbilical vein endothelial cells (HUVECs). We found that knockdown of Clock or Bmal1 lead to upregulation of MMP9 in HUVECs, and that Clock and Bmal1 expression was elevated while MAPK pathways were blocked. Atherosclerotic apolipoproteinE-deficient mice consumed a high-fat diet were used and treated with acrolein (3 mg/kg/day) in the drinking water for 12 weeks. Upregulation of MMP9, and downregulation of Clock and Bmal1 were also observed in plasma of the mice. Besides, acrolein feeding altered gut microbiota composition at a phylum level especially for an increased Firmicutes and a decreased Bacteroidetes. Additionally, gut microbiota showed correlation with atherosclerotic plaque, MMP9 and Bmal1 levels. Therefore, our findings indicated that acrolein increased the expression of MMP9 through MAPK regulating circadian clock, which was associated with gut microbiota regulation in atherosclerosis. Circadian rhythms and gut microbiota might be promising targets in the prevention of cardiovascular disease caused by environmental pollutants.

Melatonin and age-related cardiovascular diseases

The pineal gland is a neuroendocrine gland closely related to human aging. Melatonin is a kind of indole neuroendocrine hormone secreted by the pineal gland, which is essential for maintaining physiological function. Many researches found that melatonin plays a key role in anti-aging-related cardiovascular diseases. In this paper, the latest advances in the study of melatonin and aging-related cardiovascular diseases are reviewed, and their related physiological functions and mechanisms are discussed.

Melatonin: Protection against age-related cardiac pathology

Aging is a complex and progressive process that involves physiological and metabolic deterioration in every organ and system. Cardiovascular diseases are one of the most common causes of mortality and morbidity among elderly subjects worldwide. Most age-related cardiovascular disorders can be influenced by modifiable behaviours such as a healthy diet rich in fruit and vegetables, avoidance of smoking, increased physical activity and reduced stress. The role of diet in prevention of various disorders is a well-established factor, which has an even more important role in the geriatric population. Melatonin, an indoleamine with multiple actions including antioxidant properties, has been identified in a very large number of plant species, including edible plant products and medical herbs. Among products where melatonin has been identified include wine, olive oil, tomato, beer, and others. Interestingly, consumed melatonin in plant foods or melatonin supplementation may promote health benefits by virtue of its multiple properties and it may counteract pathological conditions also related to cardiovascular disorders, carcinogenesis, neurological diseases and aging. In the present review, we summarized melatonin effects against age-related cardiac alterations and abnormalities with a special focus on heart ischemia/reperfusion (IR) injury and myocardial infarction.

Diurnal variation of tight junction integrity associates inversely with matrix metalloproteinase expression in Xenopus laevis corneal epithelium: implications for circadian regulation of homeostatic surface cell desquamation

Background and Objectives

The corneal epithelium provides a protective barrier against pathogen entrance and abrasive forces, largely due to the intercellular junctional complexes between neighboring cells. After a prescribed duration at the corneal surface, tight junctions between squamous surface cells must be disrupted to enable them to desquamate as a component of the tissue homeostatic renewal. We hypothesize that matrix metalloproteinase (MMPs) are secreted by corneal epithelial cells and cleave intercellular junctional proteins extracellularly at the epithelial surface. The purpose of this study was to examine the expression of specific MMPs and tight junction proteins during both the light and dark phases of the circadian cycle, and to assess their temporal and spatial relationships in the Xenopus laevis corneal epithelium.

Methodology/Principal Findings

Expression of MMP-2, tissue inhibitor of MMP-2 (TIMP-2), membrane type 1-MMP (MT1-MMP) and the tight junction proteins occludin and claudin-4 were examined by confocal double-label immunohistochemistry on corneas obtained from Xenopus frogs at different circadian times. Occludin and claudin-4 expression was generally uniformly intact on the surface corneal epithelial cell lateral membranes during the daytime, but was frequently disrupted in small clusters of cells at night. Concomitantly, MMP-2 expression was often elevated in a mosaic pattern at nighttime and associated with clusters of desquamating surface cells. The MMP-2 binding partners, TIMP-2 and MT1-MMP were also localized to surface corneal epithelial cells during both the light and dark phases, with TIMP-2 tending to be elevated during the daytime.

Conclusions/Significance

MMP-2 protein expression is elevated in a mosaic pattern in surface corneal epithelial cells during the nighttime in Xenopus laevis, and may play a role in homeostatic surface cell desquamation by disrupting intercellular junctional proteins. The sequence of MMP secretion and activation, tight junction protein cleavage, and subsequent surface cell desquamation and renewal may be orchestrated by nocturnal circadian signals.

The effect of solar-geomagnetic activity during and after admission on survival in patients with acute coronary syndromes

A number of studies have established the effects of solar-geomagnetic activity on the human cardio-vascular system. It is plausible that the heliophysical conditions existing during and after hospital admission may affect survival in patients with acute coronary syndromes (ACS). We analyzed data from 1,413 ACS patients who were admitted to the Hospital of Kaunas University of Medicine, Lithuania, and who survived for more than 4 days. We evaluated the associations between active-stormy geomagnetic activity (GMA), solar proton events (SPE), and solar flares (SF) that occurred 0-3 days before and after admission, and 2-year survival, based on Cox's proportional-hazards model, controlling for clinical data. After adjustment for clinical variables, active-stormy GMA on the 2nd day after admission was associated with an increased (by 1.58 times) hazard ratio (HR) of cardiovascular death (HR=1.58, 95 % CI 1.07-2.32). For women, geomagnetic storm (GS) 2 days after SPE occurred 1 day after admission increased the HR by 3.91 times (HR=3.91, 95 % CI 1.31-11.7); active-stormy GMA during the 2nd-3rd day after admission increased the HR by over 2.5 times (HR=2.66, 95 % CI 1.40-5.03). In patients aged over 70 years, GS occurring 1 day before or 2 days after admission, increased the HR by 2.5 times, compared to quiet days; GS in conjunction with SF on the previous day, nearly tripled the HR (HR=3.08, 95 % CI 1.32-7.20). These findings suggest that the heliophysical conditions before or after the admission affect the hazard ratio of lethal outcome; adjusting for clinical variables, these effects were stronger for women and older patients.

Multicentric osteolysis with nodulosis and arthropathy (MONA) with cardiac malformation, mimicking polyarticular juvenile idiopathic arthritis: case report and literature review

The 'vanishing bone' syndrome multicentric osteolysis with nodulosis and arthropathy (MONA) is a rare chronic skeleton disorder caused by matrix metalloproteinase 2 (MMP2) deficiency, mimicking erosive polyarticular juvenile idiopathic arthritis. MONA is characterised by facial dysmorphism, subcutaneous fibrocollagenous nodules, carpal and tarsal osteolysis and interphalangeal joint erosions. We present the case of a 5-year-old boy with double outlet right ventricle, ventricular septal defect, coarctation of the aorta and MONA. Previously, a total of 24 cases of MONA have been reported of which six also had congenital cardiac malformations. Despite treatment attempts of our patient with methotrexate, eternacept and prednisolone, serial X-ray studies documented continuous severe bone degeneration.

CONCLUSION

The case documents the natural history of MONA and establishes a link between MMP2 deficiency and heart development, and given the recurring cardiac association, we suggest that all MONA patients be examined for possible cardiac defects.

Melatonin ameliorates vascular endothelial dysfunction, inflammation, and atherosclerosis by suppressing the TLR4/NF-κB system in high-fat-fed rabbits

Vascular endothelial dysfunction (VED) and inflammation contribute to the initiation and progression of atherosclerosis. Melatonin (MLT) normalizes lipid profile, improves endothelial function, and possesses anti-inflammatory properties. However, the precise mechanisms are still unclear. This study investigated whether MLT could ameliorate VED, inflammation, and atherosclerosis by suppressing the Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) system in high-fat-fed rabbits. Rabbits were randomly divided into three groups that received a standard diet (control group), high-cholesterol diet (atherosclerosis group), or high-cholesterol diet plus 10 mg/kg/day MLT (MLT group) for 12 wk. After treatment, high-fat diet significantly increased serum lipid and inflammatory markers in rabbits in atherosclerosis group compared with that in control group. In addition, high-fat diet also induced VED and typical atherosclerotic plaque formation and increased intima/media thickness ratio, which were significantly improved by MLT therapy as demonstrated in MLT group. Histological and immunoblot analysis further showed that high-fat diet enhanced the expressions of TLR4, myeloid differentiation primary response protein (MyD88), and NF-κB p65, but decreased inhibitor of NF-κB (IκB) expression. By contrast, MLT therapy decreased the expressions of TLR4, MyD88, and NF-κB p65 and increased IκB expression. This study has demonstrated that MLT ameliorates lipid metabolism, VED, and inflammation and inhibits the progression of atherosclerosis in high-fat-fed rabbits. Moreover, our study indicates for the first time that suppression of the TLR4/NF-κB system in local vasculature with atherosclerotic damage is important for the protective effects of MLT.

Melatonin protects against isoproterenol-induced alterations in cardiac mitochondrial energy-metabolizing enzymes, apoptotic proteins, and assists in complete recovery from myocardial injury in rats

The present study was undertaken to explore the protective effect of melatonin against isoproterenol bitartrate (ISO)-induced rat myocardial injury and to test whether melatonin has a role in preventing myocardial injury and recovery when the ISO-induced stress is withdrawn. Treatment for rats with ISO altered the activities of some of the key mitochondrial enzymes related to energy metabolism, the levels of some stress proteins, and the proteins related to apoptosis. These changes were found to be ameliorated when the animals were pretreated with melatonin at a dose of 10 mg/kg BW, i.p. In addition to its ability to reduce ISO-induced mitochondrial dysfunction, we also studied the role of melatonin in the recovery of the cardiac tissue after ISO-induced damage. Continuation of melatonin treatment in rats after the withdrawal of ISO treatment was found to reduce the activities of cardiac injury biomarkers including serum glutamate oxaloacetate transaminase (SGOT), lactate dehydrogenase (LDH), and cardio-specific LDH1 to control levels. The levels of tissue lipid peroxidation and reduced glutathione were also brought back to that seen in control animals by continued melatonin treatment. Continuation of melatonin treatment in post-ISO treatment period was also found to improve cardiac tissue morphology and heart function. Thus, the findings indicate melatonin’s ability to provide cardio protection at a low pharmacological dose and its role in the recovery process. Melatonin, a molecule with very low or no toxicity may be considered as a therapeutic for the treatment for ischemic heart disease.

Matrix metalloproteinase 2 and 9 dysfunction underlie vascular stiffness in circadian clock mutant mice

OBJECTIVE

To determine if elasticity in blood vessels is compromised in circadian clock-mutant mice (Bmal1-knockout [KO] and Per-triple KO) and if matrix metalloproteinases (MMPs) might confer these changes in compliance.

METHODS AND RESULTS

High-resolution ultrasonography in vivo revealed impaired remodeling and increased pulse-wave velocity in the arteries of Bmal1-KO and Per-triple KO mice. In addition, compliance of remodeled arteries and naïve pressurized arterioles ex vivo from Bmal1-KO and Per-triple KO mice was reduced, consistent with stiffening of the vascular bed. The observed vascular stiffness was coincident with dysregulation of MMP-2 and MMP-9 in Bmal1-KO mice. Furthermore, inhibition of MMPs improved indexes of pathological remodeling in wild-type mice, but the effect was abolished in Bmal1-KO mice.

CONCLUSIONS

Circadian clock dysfunction contributes to hardening of arteries, which may involve impaired control of the extracellular matrix composition.

Melatonin and circadian biology in human cardiovascular disease

Diurnal rhythms influence cardiovascular physiology, i.e. heart rate and blood pressure, and they appear to also modulate the incidence of serious adverse cardiac events. Diurnal variations occur also at the molecular level including changes in gene expression in the heart and blood vessels. Moreover, the risk/benefit ratio of some therapeutic strategies and the concentration of circulating cardiovascular system biomarkers may also vary across the 24-hr light/dark cycle. Synchrony between external and internal diurnal rhythms and harmony among molecular rhythms within the cell are essential for normal organ biology. Diurnal variations in the responsiveness of the cardiovascular system to environmental stimuli are mediated by a complex interplay between extracellular (i.e. neurohumoral factors) and intracellular (i.e. specific genes that are differentially light/dark regulated) mechanisms. Neurohormones, which are particularly relevant to the cardiovascular system, such as melatonin, exhibit a diurnal variation and may play a role in the synchronization of molecular circadian clocks in the peripheral tissue and the suprachiasmatic nucleus. Moreover, mounting evidence reveals that the blood melatonin rhythm has a crucial role in several cardiovascular functions, including daily variations in blood pressure. Melatonin has antioxidant, anti-inflammatory, chronobiotic and, possibly, epigenetic regulatory functions. This article reviews current knowledge related to the biological role of melatonin and its circadian rhythm in cardiovascular disease.

Melatonin protects against isoproterenol-induced myocardial injury in the rat: antioxidative mechanisms

The present study was undertaken to explore the protective effect of melatonin against isoproterenol bitartrate (ISO)-induced myocardial injury in rat. Treatment of rats with ISO increased the level of lipid peroxidation products and decreased the reduced glutathione levels in cardiac tissue indicating that this synthetic catecholamine induces oxidative damage following oxidative stress. Pretreatment of ISO-injected rats with melatonin at a dose of 10 mg/kg body weight, i.p. prevented these changes. Additionally, melatonin also restored the activities and the levels of antioxidant enzymes which were found to be altered by ISO treatment. Treatment of rats with ISO resulted into an increased generation of hydroxyl radicals with melatonin pretreatment significantly reducing their production. Finally, treatment of rats with ISO caused a lowering of systolic pressure with reduced cardiac output and diastolic dysfunction whereas melatonin pretreatment significantly restored many of these parameters to normal. The findings document melatonin's ability to provide cardio protection at a low pharmacological dose. Melatonin has virtually no toxicity which raises the possibility of this indole being a therapeutic treatment for ischemic heart disease.

Association between matrix metalloproteinase-10 concentration and smoking in individuals without cardiovascular disease

INTRODUCTION AND OBJECTIVES

Smoking is an important cardiovascular risk factor whose underlying mechanism is incompletely understood. However, it has been suggested that alterations in the balance between synthesis and degradation of the extracellular matrix (ECM) may play a role. The aim of this study was to determine whether there is an independent association between smoking and the concentration of circulating metalloproteinases (MMPs) in individuals without cardiovascular disease.

METHODS

Metabolic parameters, the carotid intima-media thickness (IMT), inflammatory markers (fibrinogen, C-reactive protein and interleukin-6), markers of endothelial damage (e.g., von Willebrand factor), and the concentration of MMP-1, -9 and -10 and tissue inhibitor of metalloproteinase-1 (TIMP-1) were assessed in 400 asymptomatic individuals with cardiovascular risk factors. Subjects were divided into non-smokers (n=195), smokers (n=118) and former smokers (n=87). In addition, global cardiovascular risk was determined from PROCAM and REGICOR scores.

RESULTS

Both MMP-1 and MMP-10 concentrations were significantly higher in smokers than non-smokers (P< .05 and P< .001, respectively), though there was no difference in the levels of MMP-9, TIMP-1, IMT and other inflammatory parameters. There were positive correlations between the MMP-10 concentration and PROCAM and REGICOR scores (P< .001). Multivariate analysis showed that there was still an association between smoking and the MMP-10 concentration after adjustment for age, sex and other cardiovascular risk factors (P< .001). Multiple regression analysis showed that smoking accounted for 28% of the variability in the MMP-10 concentration.

CONCLUSIONS

There was an independent association between smoking and the MMP-10 concentration in asymptomatic individuals. This relationship between MMP-10 and the ECM may indicate a mechanism through which this MMP contributes to smoking-related atherosclerosis.

Immunomodulation by chronobiologically-based glucocorticoids treatment for multiple sclerosis relapses

This study compares the effects of daytime versus nighttime intravenous glucocorticoid treatment of multiple sclerosis (MS) relapses for several immune indicators. The levels of serum CRP, TNFalpha, ESR, MMP-2, MMP-9, TIMP-1, and TIMP-2 were determined at trial entry and at day 7 post therapy initiation in 35 MS patients. Serum MMP-9 protein levels were differentially affected by treatment regimen, and were significantly lower after nighttime treatment. Both treatment protocols led to a similar reduction of ESR, CRP and TNFalpha. These findings provide preliminary characterization of biomarkers in the application of chronobiology-based glucocorticoid therapeutics in MS and other immune disorders.

Light/dark patterns of soluble vascular cell adhesion molecule-1 in relation to melatonin in patients with ST-segment elevation myocardial infarction

Elevated levels of soluble cellular adhesion molecules have been reported in patients with acute coronary syndromes. Likewise, a relation between decreased nocturnal melatonin levels and coronary artery disease has been suggested. The aim of the present study was to investigate the day-night variations in the concentration of soluble vascular cell adhesion molecule-1 (sVCAM-1) in patients with ST-segment elevation myocardial infarction (STEMI) in relation to the light/dark melatonin pattern. Ninety consecutive patients with STEMI who were admitted to the Coronary Care Unit of our institution were studied. We also recruited 70 age- and gender-matched healthy normal subjects. Blood samples were drawn at 09:00 and 02:00 hr, while patients were at rest, for the assessment of sVCAM-1 and melatonin, which were measured using commercially available ELISA. In STEMI patients, melatonin concentrations maintained a diurnal variation, but the difference between nocturnal and diurnal levels was less than that in healthy subjects (P < 0.0001). In contrast to findings with melatonin, sVCAM-1 levels showed no diurnal variations in control subjects. In the STEMI group, however, sVCAM-1 concentration at 02:00 hr was significantly higher than that during the light phase (09:00 hr; 1391 +/- 38 versus 1200 +/- 43 ng/mL, P < 0.05). The results suggest that diurnal variations in endogenous sVCAM-1 production in STEMI patients might be related to an attenuated circadian secretion of melatonin.

Association of ischemia-modified albumin and melatonin in patients with ST-elevation myocardial infarction

INTRODUCTION

It has been proposed that reactive oxygen species (ROS) generated during myocardial ischemia-reperfusion modify the N-terminus of serum albumin resulting in ischemia-modified albumin (IMA) formation. Likewise, several recent publications provide evidence that melatonin, a circadian endogenously produced indolamine, is a direct scavenger of ROS. We sought to investigate the relationship between IMA and melatonin in ST- elevation myocardial infarction (STEMI).

METHODS

We compared IMA and melatonin levels in 27 patients with STEMI undergoing primary angioplasty and 20 age- and gender-matched healthy normal subjects. Blood samples were drawn at 02:00h (night period) and 09:00h (day period) while patients were resting, to assess IMA and melatonin.

RESULTS

In both groups, melatonin concentrations maintained a diurnal variation, but the difference between nocturnal and diurnal levels was less in the STEMI-patients than in the control group (p<0.001). In contrast to findings about melatonin, IMA levels showed no diurnal variations in control subjects. However, the STEMI group showed a diurnal fluctuation with significantly higher levels at 02:00h (p<0.01). The association between IMA and melatonin remained statistically significant after adjustment for cardiovascular risk factors. An inverse correlation between IMA and melatonin at 02:00h and at 09:00h was observed, with respective r-values of -0.42 (p<0.03) and -0.57 (p<0.002).

CONCLUSIONS

Circulating IMA is negatively correlated to melatonin in STEMI-patients. Our results suggest that melatonin might exert a beneficial effect as a radical scavenger in a human model of myocardial ischemia-reperfusion.