Epigenetics of Circadian Rhythm Disruption in Cardiovascular Diseases

Circadian rhythm influences the regulation of homeostasis and physiological processes, and its disruption could lead to metabolic disorders and cardiovascular diseases (CVD). CVDs are still the dominant cause of death worldwide, which are related to numerous environmental and hereditary risk factors. Environmental and hereditary factors can clarify a small fraction of the CVD risk discrepancy. Epigenomics is a very bright strategy that will complement the knowledge of the genetic basis of CVDs. Epigenetic mechanisms allow cells to reply promptly to environmental changes and include DNA methylation, histone modification, and noncoding RNA alterations. According to research data, the circadian rhythm regulates many epigenetic regulators. The challenge is to understand how epigenetic events happen rhythmically in tissues that are involved in the development of CVDs. Epigenetic events are possibly reversible through their interface with environmental and nutritional factors, allowing innovative preventive and therapeutic strategies in cardiovascular diseases

Circadian rhythm and myocardial infarction

Cirkadijalni sat kontrolira cijeli niz fizioloških procesa, a njegovi poremećaji mogu dovesti do brojnih patofizioloških promjena. Središnji cirkadijalni sat smješten je u suprahijazmatskoj jezgri u hipotalamusu i reguliran je brojim genima cirkadijalnog ritma. Varijacije tih gena povezane su s pretilošću, poremećajima spavanja, metaboličkim i raznim psihičkim poremećajima te kardiovaskularnim događajima, poput infarkta miokarda, moždanog udara i vaskularne smrti. Mnogi kardiovaskularni procesi pokazuju jasne dnevne varijacije ovisne o cirkadijalnom ritmu (tlak, otkucaji srca), a cirkadijalni obrazac pojavnost karakterističan je za kardiovaskularne bolesti. Kronotip i dnevna pospanost, elementi cirkadijalnog ritma, važni su čimbenici rizika u procijeni nastanaka kardiovaskularnih bolesti, odnosno infarkta. Rad donosi pregled o najnovijim spoznajama utjecaja cirkadijalnog ritma, gena cirkadijalnog ritma i fenotipskih elemenata cirkadijalnog ritma, tj. kronotipa i dnevne pospanosti, na nastanak infarkta miokarda. U doba personalizirane medicine, znanje o cirkadijalnom ritmu pojedine osobe može biti važno za njezino liječenje, a može se uključiti i u dijagnostičke procese.The circadian clock controls many physiological processes, and its abnormalities can lead to many pathophysiological disorders. The central circadian clock is located in the suprachiasmatic nucleus in the hypothalamus and is regulated by numerous circadian clock genes. Variations in these genes have been linked to obesity, sleep disorders, metabolic and psychological disorders, and cardiovascular events such as myocardial infarction, stroke, and vascular death. Many cardiovascular processes show daily variations depending on the circadian rhythm (blood pressure, heart rate), and the circadian pattern is characteristic for cardiovascular diseases. Chronotype and daytime sleepiness, circadian rhythm elements, are significant risk factors in the assessment of the cardiovascular disease occurrence, especially myocardial infarction. This paper presents a review of the latest knowledge of the impact of circadian rhythm, circadian rhythm genes, and circadian rhythm elements (chronotype and daytime sleepiness) on myocardial infarction. Nowadays, in the time of personalized medicine, it is essential to know the circadian rhythm of an individual for its treatment and possible involvement in the diagnostic procedures

Validation of screening method for dynamic mutation in the FMR1 gene

Ciljevi istraživanja su sljedeći: a) validacija metode izravnoga PCR-a s tri početnice (engl. direct triplet-primed PCR, dTP-PCR) za određivanje dinamičkih mutacija u genu FMR1, te b) usporedba rezultata dobivenih metodom dTP-PCR s rezultatima dobivenim Southern blot metodom. Uzorak ispitanika sastojao se od 40 pacijenata upućenih u Klinički bolnički centar (KBC) Osijek s dijagnozom intelektualnog zaostajanja. Ispitanici su nasumično izabrani i validacija je provedena slijepim istraživanjem. Izolacija genomske DNA napravljena je iz pune krvi. Broj tripleta CGG gena FMR1 utvrđen je metodom izravne lančane reakcije polimeraze u stvarnom vremenu s tri početnice (dTP-PCR) uz analizu krivulje mekšanja DNA. Analizom krivulje mekšanja utvrđena je temperatura mekšanja za svaki umnoženi uzorak DNA ispitanika. Temeljem razlike u temperaturi mekšanja ispitivanoga uzorka i kontrolnih uzoraka s poznatim brojem ponavljanja tripleta CGG (30, 41 i 53 ponavljanja) svi su ispitanici svrstani u četiri kategorije (normalan broj CGG tripleta ≤ 44 CGG, siva zona od 45 do 54 CGG, premutacija od 55 do 200 CGG i puna mutacija > 200 CGG). Prisutnost proširenih alela (> 200 tripleta CGG) kod osoba oba spola imala je drugačiju krivulju mekšanja DNA od normalnih alela ( 30) u genu FMR1. Metoda dTP-PCR-a primjerena je za brzi probir promjene broja ponavljanja tripleta CGG, kao i za otkrivanje nositelja premutacija i mutacija u genu FMR1 u populaciji ispitanika koja obuhvaća osobe s intelektualnim poteškoćama nepoznatoga uzroka.Objectives of this study are validation of the direct triplet-primed PCR method (dTP-PCR) for determination of dynamic mutation in the FMR1 gene, and comparison of the results of dTP-PCR method and Southern blot analysis. In this study 40 patients from Osijek University Hospital with diagnosis of the intellectual disability were included. The patients were chosen randomly and validation of the method was conducted as a blind study. DNA was extracted from the whole blood. The number of the CGG repeats in the FMR1 gene is determined by direct triplet-primed PCR method and melting curve analysis. Cut-off temperature between normal and permutation of the CGG repeats is determined by control samples with known number of CGG repeats. All patients are classified in four categories based on DNA melting curve (normal number of CGG repeats ≤44, grey zone 45 to 54 CGG repeats, premutation 55 to 200 CGG repeats, and full mutation >200 CGG repeats). Presence of expanded alleles (>200 CGG repeats) in both sex had different DNA melting curve than the melting curve of normal allele (30) repeats in FMR1 gene. This method is appropriate for quick determination of allelic changes in the FMR1 gene, screening population and defining mutations or permutation carriers in the population with intellectual disabilities with unknown cause

Myocardial Infarction and Circadian Rhythm

Human physiological activity and condition during illness are under the control of the circadian rhythm. Circadian rhythms handle a wide diversity of physiological and metabolic functions, and the interruption of these rhythms has been linked to obesity, sleep disorders, metabolic and psychological disorders, and cardiovascular events such as myocardial infarction (MI), stroke, and vascular death. Disruption of circadian rhythms increases the risk of developing myocardial infarction, indicating that circadian genes might play an essential role in determining disease susceptibility. It is well known that many cardiovascular processes show daily variations depending on the circadian rhythm (blood pressure, heart rate), and the gene expression of the cardiomyocyte circadian clock influences myocardial contractile function, metabolism, and other gene expressions. We present a review of the latest knowledge on the impact of circadian rhythm and circadian rhythm genes on myocardial infarction. Today, in a time of personalized medicine, it is essential to know each person’s circadian rhythm for its treatment and possible inclusion in the diagnostic procedures

De Novo Case of a Partial Trisomy 4p and a Partial Monosomy 8p

The extent of clinical expression in cases of segmental aneuploidy often varies depending on the size of the chromosomal region involved. Here we present clinical and cytogenetic findings in a 5-month old boy with a duplication of a chromosomal segment 4p16.1→4pter and a deletion of a chromosomal segment 8p23.1→8pter. His karyotype was determined by applying classical GTG banding and FISH method (WHCR region, centromere 4, centromere 8, telomere 8p) as 46,XY,der(8)t(4;8)(p16.1;p23.1).ish der(8)t(4;8)(D8S504-,WHCR+,D8Z2+)dn. Parents are not related and have normal karyotypes, indicating de novo origin. We have compared similarity of the clinical features in our proband to other patients carrying only a duplication of the distal part of 4p or a deletion of distal part of 8p or similar combination described in the literature

The effect of subminimal inhibitory concentrations of antibiotics on the adherence ability of Pseudomonas aeruginosa to epithelial cells in vitro

Background and purpose: The aim of this study was to examine the influence of subminimal inhibitory concentrations (subMICs) of ceftazidime, ciprofloxacin and gentamicin on the adherence ability and morphology of wild-type Pseudomonas aeruginosa strains to the Buffalo green monkey kidney cell line, using indirect immunofluorescence staining. Materials and methods: Bacterial adherence changes were tested before and after exposure to 1/2, 1/4, 1/8, 1/16 and 1/32 MIC of antibiotics. Results: A statistical difference in the number of attached bacteria after exposure to all subMICs of ceftazidime and ciprofloxacin was observed (p<0.05), even after only 1/2 MIC of gentamicin. Conclusion: The results of this study have shown that antibiotics in much lower concentrations than those necessary for inhibition of bacterial multiplications could damage the adherence of Pseudomonas aeruginosa to the epithelial cell line

The effect of subminimal inhibitory concentrations of antibiotics on the adherence ability of Pseudomonas aeruginosa to epithelial cells in vitro

Background and purpose: The aim of this study was to examine the influence of subminimal inhibitory concentrations (subMICs) of ceftazidime, ciprofloxacin and gentamicin on the adherence ability and morphology of wild-type Pseudomonas aeruginosa strains to the Buffalo green monkey kidney cell line, using indirect immunofluorescence staining. Materials and methods: Bacterial adherence changes were tested before and after exposure to 1/2, 1/4, 1/8, 1/16 and 1/32 MIC of antibiotics. Results: A statistical difference in the number of attached bacteria after exposure to all subMICs of ceftazidime and ciprofloxacin was observed (p<0.05), even after only 1/2 MIC of gentamicin. Conclusion: The results of this study have shown that antibiotics in much lower concentrations than those necessary for inhibition of bacterial multiplications could damage the adherence of Pseudomonas aeruginosa to the epithelial cell line

Povezanost cirkadijalnog ritma s infarktom miokarda

Cardiovascular diseases are the world’s leading cause of death. Human physiologic activities and state during illness are under the control of circadian rhythm. The aim of the study was to determine the potential association of chronotype and daytime sleepiness with susceptibility to myocardial infarction. We conducted a case-control study on 200 patients hospitalized due to myocardial infarction and 200 healthy controls. Systematic information on the past and present medical history was obtained from all participants. Chronotype was assessed using the Morningness-Eveningness Questionnaire (MEQ), and daytime sleepiness was assessed by the Epworth Sleepiness Scale (ESS). The mean age of the study population was 64±13 years, and 54.5% were male. There was no significant difference in MEQ (58.88±6.52 vs. 58.46±7.78, p=0.601) or ESS (5 (interquartile range, IQR 4-7.5) vs. 6 (IQR 3-8), p=0.912) score between patients and controls. Nevertheless, we found statistically significant differences related to risk factors for cardiovascular diseases, such as hypertension, dyslipidemia, and diabetes mellitus. However, there was no association of MEQ and ESS score with myocardial infarction in the study population.Kardiovaskularne bolesti su vodeći uzrok smrtnosti u svijetu. Pod kontrolom cirkadijalnog sata su humana fiziologija i fiziološka stanja tijekom bolesti. Cilj ovoga istraživanja bio je utvrditi potencijalnu povezanost kronotipa i dnevne pospanosti s infarktom miokarda. Provedeno je istraživanje slučajeva i kontrola na 200 bolesnika s infarktom miokarda te 200 zdravih kontrolnih ispitanika. Od svih ispitanika prikupljeni su podaci o prošloj i trenutnoj medicinskoj anamnezi. Kronotip je procijenjen pomoću upitnika MEQ (Morningness-Eveningness Questionnaire), a dnevna pospanost pomoću Epworthove ljestvice pospanosti (ESS, Epworth Sleepiness Scale). Prosječna životna dob ispitivane populacije bila je 64±13 godina, a 54,5% ispitanika činili su muškarci. Statistički značajna razlika nije pronađena između bolesnika i kontrola u kronotipu (58,88±6,52 nasuprot 58,46±7,78; p=0,601) i dnevnoj pospanosti (5 (IQR 4-7,5) nasuprot 6 (IQR 3-8); p=0,912). Unatoč tome, pronađena je statistički značajna razlika povezana sa čimbenicima rizika za kardiovaskularne bolesti kao što su hipertenzija, dislipidemija i dijabetes. Međutim, u ovom istraživanju nije utvrđena povezanost kronotipa i dnevne pospanosti s infarktom miokarda

The effect of subminimal inhibitory concentrations of antibiotics on the adherence ability of Pseudomonas aeruginosa to epithelial cells in vitro

Background and purpose: The aim of this study was to examine the influence of subminimal inhibitory concentrations (subMICs) of ceftazidime, ciprofloxacin and gentamicin on the adherence ability and morphology of wild-type Pseudomonas aeruginosa strains to the Buffalo green monkey kidney cell line, using indirect immunofluorescence staining. Materials and methods: Bacterial adherence changes were tested before and after exposure to 1/2, 1/4, 1/8, 1/16 and 1/32 MIC of antibiotics. Results: A statistical difference in the number of attached bacteria after exposure to all subMICs of ceftazidime and ciprofloxacin was observed (p Conclusion: The results of this study have shown that antibiotics in much lower concentrations than those necessary for inhibition of bacterial multiplications could damage the adherence of Pseudomonas aeruginosa to the epithelial cell line.</p