The toposiomerase IIIalpha-RMI1-RMI2 complex orients human Bloom’s syndrome helicase for efficient disruption of D-loops

Homologous recombination (HR) is a ubiquitous and efficient process that serves the repair of severe forms of DNA damage and the generation of genetic diversity during meiosis. HR can proceed via multiple pathways with different outcomes that may aid or impair genome stability and faithful inheritance, underscoring the importance of HR quality control. Human Bloom’s syndrome (BLM, RecQ family) helicase plays central roles in HR pathway selection and quality control via unexplored molecular mechanisms. Here we show that BLM’s multi-domain structural architecture supports a balance between stabilization and disruption of displacement loops (D-loops), early HR intermediates that are key targets for HR regulation. We find that this balance is markedly shifted toward efficient D-loop disruption by the presence of BLM’s interaction partners Topoisomerase IIIα-RMI1-RMI2, which have been shown to be involved in multiple steps of HR-based DNA repair. Our results point to a mechanism whereby BLM can differentially process D-loops and support HR control depending on cellular regulatory mechanisms

Intestinal alkaline phosphatase in the colonic mucosa of children with inflammatory bowel disease

AIM: To investigate intestinal alkaline phosphatase (iAP) in the intestinal mucosa of children with inflammatory bowel disease (IBD). METHODS: Colonic biopsy samples were taken from 15 newly diagnosed IBD patients and from 10 healthy controls. In IBD patients, specimens were obtained both from inflamed and non-inflamed areas. The iAP mRNA and protein expression was determined by reverse transcription-polymerase chain reaction and Western blotting analysis, respectively. Tissue localization of iAP and Toll-like receptor (TLR) 4 was investigated by immunofluorescent staining. RESULTS: The iAP protein level in the inflamed mucosa of children with Crohn's disease (CD) and ulcerative colitis (UC) was significantly decreased when compared with controls (both P < 0.05). Similarly, we found a significantly decreased level of iAP protein in the inflamed mucosa in CD compared with non-inflamed mucosa in CD (P < 0.05). In addition, the iAP protein level in inflamed colonic mucosa in patients with UC was decreased compared with non-inflamed mucosa in patients with CD (P < 0.05). iAP protein levels in the non-inflamed mucosa of patients with CD were similar to controls. iAP mRNA expression in inflamed colonic mucosa of children with CD and UC was not significantly different from that in non-inflamed colonic mucosa with CD. Expression of iAP mRNA in patients with non-inflamed mucosa and in controls were similar. Co-localization of iAP with TLR4 showed intense staining with a dotted-like pattern. iAP was present in the inflamed and non-inflamed mucosa of patients with CD, UC, and in control biopsy specimens, irrespective of whether it was present in the terminal ileum or in the colon. However, the fluorescent signal of TLR4 was more pronounced in the colon compared with the terminal ileum in all groups studied. CONCLUSION: Lower than normal iAP protein levels in inflamed mucosa of IBD patients may indicate a role for iAP in inflammatory lesions in IBD. Based on our results, administration of exogenous iAP enzyme to patients with the active form of IBD may be a therapeutic option

Altered irisin/BDNF axis parallels excessive daytime sleepiness in obstructive sleep apnea patients

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Complete Genome Sequence of a Genotype G23P[37] Pheasant Rotavirus Strain Identified in Hungary

We investigated the genomic properties of a rotavirus A strain isolated from diarrheic pheasant poults in Hungary in 2015. Sequence analyses revealed a shared genomic constellation (G23-P[37]-I4-R4-C4-M4-A16-N10-T4-E4-H4) and close relationship (range of nucleotide sequence similarity: VP2, 88%; VP1 and NSP4, 98%) with another pheasant rotavirus strain isolated previously in Germany

Antioxidant Capacity Determination of Hungarian-, Slovak-, and Polish-Origin Goldenrod Honeys

The goldenrod (Solidago) species are flowering plants that produce nectar and can be the sources of unifloral honeys. S. canadensis and S. gigantea are native to North America and invasive in several European countries, while S. virgaurea is native to Europe. The aim of this work was to determine and compare the antioxidant capacity of goldenrod honeys collected in three central European countries (Hungary, Poland, and Slovakia), from three locations within each country. The botanical origin of each honey sample was checked with melissopalynological analysis. Color intensity was determined using the Pfund scale. The antioxidant activity was determined with different spectrophotometric methods (DPPH, ABTS, and FRAP). The content of total polyphenols, flavonoids, and phenolic acids was quantified using spectrophotometric methods. The highest radical-scavenging activity was identified for Hungarian samples with all three antioxidant capacity assays. Medium antioxidant activity was described for Slovak samples. The DPPH and ABTS assays discriminated Polish honeys with the lowest antioxidant activity. The highest flavonoid and phenolic acid content was detected in Hungarian and Slovak honeys, while the lowest values were measured in Polish samples. Our study shows that the antioxidant capacity of unifloral goldenrod honeys can be different in various countries of origin, correlating with color intensity and polyphenol content

Highly potent dUTPase inhibition by a bacterial repressor protein reveals a novel mechanism for gene expression control

Transfer of phage-related pathogenicity islands of Staphylococcus aureus (SaPI-s) was recently reported to be activated by helper phage dUTPases. This is a novel function for dUTPases otherwise involved in preservation of genomic integrity by sanitizing the dNTP pool. Here we investigated the molecular mechanism of the dUTPase-induced gene expression control using direct techniques. The expression of SaPI transfer initiating proteins is repressed by proteins called Stl. We found that Φ11 helper phage dUTPase eliminates SaPIbov1 Stl binding to its cognate DNA by binding tightly to Stl protein. We also show that dUTPase enzymatic activity is strongly inhibited in the dUTPase:Stl complex and that the dUTPase:dUTP complex is inaccessible to the Stl repressor. Our results disprove the previously proposed G-protein-like mechanism of SaPI transfer activation. We propose that the transfer only occurs if dUTP is cleared from the nucleotide pool, a condition promoting genomic stability of the virulence elements

Long-Term PDE-5A Inhibition Improves Myofilament Function in Left and Right Ventricular Cardiomyocytes through Partially Different Mechanisms in Diabetic Rat Hearts

Heart failure with preserved ejection fraction (HFpEF) and right ventricular (RV) dysfunc- tion are frequent complications of diabetic cardiomyopathy. Here we aimed to characterize RV and left ventricular (LV) remodeling and its prevention by vardenafil (a long-acting phosphodiesterase- 5A (PDE-5A) inhibitor) administration in a diabetic HFpEF model. Zucker Diabetic Fatty (ZDF) and control, ZDF Lean (Lean) male rats received 10 mg/kg vardenafil (ZDF + Vard; Lean + Vard) per os, on a daily basis for a period of 25 weeks. In vitro force measurements, biochemical and histochemical assays were employed to assess cardiomyocyte function and signaling. Vardenafil treatment increased cyclic guanosine monophosphate (cGMP) levels and decreased 3-nitrotyrosine (3-NT) levels in the left and right ventricles of ZDF animals, but not in Lean animals. Cardiomyocyte passive tension (Fpassive) was higher in LV and RV cardiomyocytes of ZDF rats than in those receiving preventive vardenafil treatment. Levels of overall titin phosphorylation did not differ in the four experimental groups. Maximal Ca2+-activated force (Fmax) of LV and RV cardiomyocytes were preserved in ZDF animals. Ca2+-sensitivity of isometric force production (pCa50) was significantly higher in LV (but not in RV) cardiomyocytes of ZDF rats than in their counterparts in the Lean or Lean + Vard groups. In accordance, the phosphorylation levels of cardiac troponin I (cTnI) and myosin binding protein-C (cMyBP-C) were lower in LV (but not in RV) cardiomyocytes of ZDF animals than in their counterparts of the Lean or Lean + Vard groups. Vardenafil treatment normalized pCa50 values in LV cardiomyocytes, and it decreased pCa50 below control levels in RV cardiomyocytes in the ZDF + Vard group. Our data illustrate partially overlapping myofilament protein alterations for LV and RV cardiomyocytes in diabetic rat hearts upon long-term PDE-5A inhibition. While uniform patterns in cGMP, 3-NT and Fpassive levels predict identical effects of vardenafil therapy for the diastolic function in both ventricles, the uneven cTnI, cMyBP-C phosphorylation levels and pCa50 values implicate different responses for the systolic function

Diabeteses kisér-károsodás vizsgálata optikai koherencia tomográfián alapuló angiográfiával = Evaluation of diabetic microangiopathy using optical coherence tomography angiography

Absztrakt: Bevezetés: Az optikai koherencia tomográfián alapuló angiográfia új noninvazív eszköz, amely lehetővé teszi a retinalis érhálózat vizsgálatát, és segítséget nyújthat a microangiopathiával járó szemfenéki betegségek nyomon követésében. Célkitűzés: Diabeteses betegek mindkét szemén optikai koherencia tomográfiás angiográfiával meghatározni a retinalis kisér-károsodás mértékét az általános rizikófaktorok függvényében. Módszer: Optikai koherencia tomográfiás angiográfia során 36 diabeteses, valamint 45 kontrollszemély mindkét szemén meghatároztuk a retinalis érhálózat sűrűségét. Rögzítettük a magas vérnyomást, a diabetes fennállási idejét, az inzulinkezelést, a HbA1c-szintet, a dyslipidaemia és a diabeteses retinopathia jelenlétét, továbbá a szem tengelyhosszát. A rizikófaktoroknak az érhálózat-sűrűségre és a két szem közötti aszimmetriára kifejtett hatását többváltozós regressziós modellekben vizsgáltuk. Eredmények: Diabeteses betegekben a retinalis érhálózat sűrűsége szignifikánsan alacsonyabb volt, mint kontrollszemélyekben (p<0,05), és ugyanazon beteg két szemének adatai között mért különbség szignifikánsan magasabb volt, mint a kontroll egészséges személyek két szeme között mért különbség (p<0,05). Mind a retinalis érsűrűség, mind a két szem közötti aszimmetria korrelált a diabetes fennállási idejével (p<0,05), kontroll alatt tartva az általános rizikófaktorok hatását. A kontrollcsoporttal összehasonlítva a két szem közötti aszimmetria mértéke szignifikánsan magasabb volt olyan diabeteses betegek két szeme között is, akiknél a diabeteses retinopathia szemfenéki jelei nem voltak láthatók (p<0,001). Következtetések: Diabeteses betegekben csökkent az érhálózat sűrűsége egészséges személyekkel összehasonlítva, továbbá fokozott a két szem közötti aszimmetria. A csökkent érhálózat-sűrűség és a két szem közötti fokozott aszimmetria a betegség fennállási idejével arányos, és alkalmas lehet a diabeteses retinopathia igen korai, szemfenékvizsgálattal még nem látható formáinak kiszűrésére, így segítve a terápia mielőbbi megkezdését. Orv Hetil. 2018; 159(8): 320–326. | Abstract: Introduction: Optical coherence tomography angiography is a non-invasive imaging technique that is able to visualize the different retinal vascular layers using motion contrast to detect blood flow without intravenous dye injection. This method might help to assess microangiopathy in diabetic retinopathy during screening and follow-up. Aim: To quantify retinal microvasculature alterations in both eyes of diabetic patients in relation to systemic risk factors using optical coherence tomography angiography. Method: Both eyes of 36 diabetic patients and 45 individuals without diabetes were examined. Duration of diabetes, insulin therapy, blood pressure, HbA1c, dyslipidemia, axial length and the presence of diabetic retinopathy were recorded. Retinal vessel density was measured by optical coherence tomography angiography. The effect of risk factors on vessel density and between-eye asymmetry was assessed using multivariable regression analysis. Results: Vessel density was significantly lower and between-eye difference was significantly higher in diabetic patients compared to controls (p<0.05). Both vessel density and between-eye asymmetry significantly correlated with diabetes duration (p<0.05) after controlling for the effect of risk factors. The between-eye asymmetry in vessel density was significantly higher in patients without clinically detectable diabetic retinopathy compared to control subjects (p<0.001). Conclusions: There is a decrease in retinal vessel density and an increase in between-eye asymmetry in patients with diabetes compared to healthy subjects. By using optical coherence tomography angiography, the detection of these microvascular alterations is possible before clinically detectable diabetic retinopathy and might serve as a useful tool in both screening and timing of treatment. Orv Hetil. 2018; 159(8): 320–326